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linux/arch/powerpc/kernel/process.c

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powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
/*
* Derived from "arch/i386/kernel/process.c"
* Copyright (C) 1995 Linus Torvalds
*
* Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
* Paul Mackerras (paulus@cs.anu.edu.au)
*
* PowerPC version
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/elf.h>
#include <linux/prctl.h>
#include <linux/init_task.h>
powerpc: various straight conversions from module.h --> export.h All these files were including module.h just for the basic EXPORT_SYMBOL infrastructure. We can shift them off to the export.h header which is a way smaller footprint and thus realize some compile time gains. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-07-23 06:24:23 +08:00
#include <linux/export.h>
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
#include <linux/kallsyms.h>
#include <linux/mqueue.h>
#include <linux/hardirq.h>
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
#include <linux/utsname.h>
powerpc64: port of the function graph tracer This is a port of the function graph tracer that was written by Frederic Weisbecker for the x86. This only works for PPC64 at the moment and only for static tracing. PPC32 and dynamic function graph tracing support will come later. The trace produces a visual calling of functions: # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | 0) 2.224 us | } 0) ! 271.024 us | } 0) ! 320.080 us | } 0) ! 324.656 us | } 0) ! 329.136 us | } 0) | .put_prev_task_fair() { 0) | .update_curr() { 0) 2.240 us | .update_min_vruntime(); 0) 6.512 us | } 0) 2.528 us | .__enqueue_entity(); 0) + 15.536 us | } 0) | .pick_next_task_fair() { 0) 2.032 us | .__pick_next_entity(); 0) 2.064 us | .__clear_buddies(); 0) | .set_next_entity() { 0) 2.672 us | .__dequeue_entity(); 0) 6.864 us | } Geoff Lavand tested on PS3. Tested-by: Geoff Levand <geoffrey.levand@am.sony.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-10 13:10:27 +08:00
#include <linux/ftrace.h>
[PATCH] idle cputime accounting The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 22:11:38 +08:00
#include <linux/kernel_stat.h>
powerpc: Randomise lower bits of stack address Randomise the lower bits of the stack address. More randomisation is good for security but the scatter can also help with SMT threads that share an L1. A quick test case shows this working: int main() { int sp; printf("%x\n", (unsigned long)&sp & 4095); } before: 80 80 80 80 80 after: 610 490 300 6b0 d80 Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-22 09:50:03 +08:00
#include <linux/personality.h>
#include <linux/random.h>
powerpc, hw_breakpoints: Implement hw_breakpoints for 64-bit server processors Implement perf-events based hw-breakpoint interfaces for PowerPC 64-bit server (Book III S) processors. This allows access to a given location to be used as an event that can be counted or profiled by the perf_events subsystem. This is done using the DABR (data breakpoint register), which can also be used for process debugging via ptrace. When perf_event hw_breakpoint support is configured in, the perf_event subsystem manages the DABR and arbitrates access to it, and ptrace then creates a perf_event when it is requested to set a data breakpoint. [Adopted suggestions from Paul Mackerras <paulus@samba.org> to - emulate_step() all system-wide breakpoints and single-step only the per-task breakpoints - perform arch-specific cleanup before unregistration through arch_unregister_hw_breakpoint() ] Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2010-06-15 14:05:19 +08:00
#include <linux/hw_breakpoint.h>
powerpc: Use probe_kernel_address in show_instructions We really don't want to take a pagefault in show_instructions, so use probe_kernel_address instead of __get_user. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-13 17:27:15 +08:00
#include <linux/uaccess.h>
powerpc: sparse: Include headers for __weak symbols Sometimes when sparse warns about undefined symbols, it isn't because they should have 'static' added, it's because they're overriding __weak symbols defined elsewhere, and the header has been missed. Fix a few of them by adding appropriate headers. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-01-06 08:45:51 +08:00
#include <linux/elf-randomize.h>
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/mmu.h>
#include <asm/prom.h>
[PATCH] powerpc: Make ppc_md.set_dabr non 64-bit specific Define ppc_md.set_dabr for both 32 + 64 bit. Cleanup the implementation for pSeries also, it was needlessly complex. Now we just do two firmware tests at setup time, and use one of two functions, rather than using one function and testing on every call. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-07 10:12:03 +08:00
#include <asm/machdep.h>
powerpc: Implement accurate task and CPU time accounting This implements accurate task and cpu time accounting for 64-bit powerpc kernels. Instead of accounting a whole jiffy of time to a task on a timer interrupt because that task happened to be running at the time, we now account time in units of timebase ticks according to the actual time spent by the task in user mode and kernel mode. We also count the time spent processing hardware and software interrupts accurately. This is conditional on CONFIG_VIRT_CPU_ACCOUNTING. If that is not set, we do tick-based approximate accounting as before. To get this accurate information, we read either the PURR (processor utilization of resources register) on POWER5 machines, or the timebase on other machines on * each entry to the kernel from usermode * each exit to usermode * transitions between process context, hard irq context and soft irq context in kernel mode * context switches. On POWER5 systems with shared-processor logical partitioning we also read both the PURR and the timebase at each timer interrupt and context switch in order to determine how much time has been taken by the hypervisor to run other partitions ("steal" time). Unfortunately, since we need values of the PURR on both threads at the same time to accurately calculate the steal time, and since we can only calculate steal time on a per-core basis, the apportioning of the steal time between idle time (time which we ceded to the hypervisor in the idle loop) and actual stolen time is somewhat approximate at the moment. This is all based quite heavily on what s390 does, and it uses the generic interfaces that were added by the s390 developers, i.e. account_system_time(), account_user_time(), etc. This patch doesn't add any new interfaces between the kernel and userspace, and doesn't change the units in which time is reported to userspace by things such as /proc/stat, /proc/<pid>/stat, getrusage(), times(), etc. Internally the various task and cpu times are stored in timebase units, but they are converted to USER_HZ units (1/100th of a second) when reported to userspace. Some precision is therefore lost but there should not be any accumulating error, since the internal accumulation is at full precision. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-24 07:06:59 +08:00
#include <asm/time.h>
Disintegrate asm/system.h for PowerPC Disintegrate asm/system.h for PowerPC. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> cc: linuxppc-dev@lists.ozlabs.org
2012-03-29 01:30:02 +08:00
#include <asm/runlatch.h>
[PATCH] powerpc: declare arch syscalls in <asm/syscalls.h> powerpc currently declares some of its own system calls in <asm/unistd.h>, but not all of them. That place also contains remainders of the now almost unused kernel syscall hack. - Add a new <asm/syscalls.h> with clean declarations - Include that file from every source that implements one of these - Get rid of old declarations in <asm/unistd.h> This patch is required as a base for implementing system calls from an SPU, but also makes sense as a general cleanup. Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-23 07:00:08 +08:00
#include <asm/syscalls.h>
Disintegrate asm/system.h for PowerPC Disintegrate asm/system.h for PowerPC. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> cc: linuxppc-dev@lists.ozlabs.org
2012-03-29 01:30:02 +08:00
#include <asm/switch_to.h>
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes When we switch out a task, we need to save both the checkpointed and the speculated state into the thread struct. Similarly when we are switching in a task we need to load both the checkpointed and speculated state. If the task was using FP, we non-lazily reload both the original and the speculative FP register states. This is because the kernel doesn't see if/when a TM rollback occurs, so if we take an FP unavoidable later, we are unable to determine which set of FP regs need to be restored. This simply adds these functions. It doesn't hook them into the existing code yet. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:37 +08:00
#include <asm/tm.h>
Disintegrate asm/system.h for PowerPC Disintegrate asm/system.h for PowerPC. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> cc: linuxppc-dev@lists.ozlabs.org
2012-03-29 01:30:02 +08:00
#include <asm/debug.h>
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
#ifdef CONFIG_PPC64
#include <asm/firmware.h>
#endif
powerpc: Fix kernel thread creation on ABIv2 Change how we setup registers for ret_from_kernel_thread. In ABIv1, instead of passing a function descriptor in, dereference it and pass the target in directly. Use ppc_global_function_entry to get it right on both ABIv1 and ABIv2. Signed-off-by: Anton Blanchard <anton@samba.org>
2014-02-04 13:08:51 +08:00
#include <asm/code-patching.h>
powerpc: sparse: Include headers for __weak symbols Sometimes when sparse warns about undefined symbols, it isn't because they should have 'static' added, it's because they're overriding __weak symbols defined elsewhere, and the header has been missed. Fix a few of them by adding appropriate headers. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-01-06 08:45:51 +08:00
#include <asm/exec.h>
powerpc/livepatch: Add livepatch stack to struct thread_info In order to support live patching we need to maintain an alternate stack of TOC & LR values. We use the base of the stack for this, and store the "live patch stack pointer" in struct thread_info. Unlike the other fields of thread_info, we can not statically initialise that value, so it must be done at run time. This patch just adds the code to support that, it is not enabled until the next patch which actually adds live patch support. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Balbir Singh <bsingharora@gmail.com>
2016-03-24 19:04:04 +08:00
#include <asm/livepatch.h>
powerpc: Move cpu_has_feature() to a separate file We plan to use jump label for cpu_has_feature(). In order to implement this we need to include the linux/jump_label.h in asm/cputable.h. Unfortunately if we do that it leads to an include loop. The root of the problem seems to be that reg.h needs cputable.h (for CPU_FTRs), and then cputable.h via jump_label.h eventually pulls in hw_irq.h which needs reg.h (for MSR_EE). So move cpu_has_feature() to a separate file on its own. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Rename to cpu_has_feature.h and flesh out change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-23 17:12:40 +08:00
#include <asm/cpu_has_feature.h>
powerpc/sparse: Add more assembler prototypes Another set of things that are only called from assembler and so need prototypes to keep sparse happy. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-06 13:32:43 +08:00
#include <asm/asm-prototypes.h>
powerpc/livepatch: Add livepatch stack to struct thread_info In order to support live patching we need to maintain an alternate stack of TOC & LR values. We use the base of the stack for this, and store the "live patch stack pointer" in struct thread_info. Unlike the other fields of thread_info, we can not statically initialise that value, so it must be done at run time. This patch just adds the code to support that, it is not enabled until the next patch which actually adds live patch support. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Balbir Singh <bsingharora@gmail.com>
2016-03-24 19:04:04 +08:00
powerpc: BookE hardware watchpoint support This patch implements support for HW based watchpoint via the DBSR_DAC (Data Address Compare) facility of the BookE processors. It does so by interfacing with the existing DABR breakpoint code and adding the necessary bits and pieces for the new bits to be properly set or cleared Signed-off-by: Luis Machado <luisgpm@br.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-24 00:10:41 +08:00
#include <linux/kprobes.h>
#include <linux/kdebug.h>
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
powerpc: Initial stack protector (-fstack-protector) support Partialy copied from commit c743f38013aef ("ARM: initial stack protector (-fstack-protector) support") This is the very basic stuff without the changing canary upon task switch yet. Just the Kconfig option and a constant canary value initialized at boot time. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-22 18:49:30 +08:00
#ifdef CONFIG_CC_STACKPROTECTOR
#include <linux/stackprotector.h>
unsigned long __stack_chk_guard __read_mostly;
EXPORT_SYMBOL(__stack_chk_guard);
#endif
powerpc: New macros for transactional memory support This adds new macros for saving and restoring checkpointed architected state from and to the thread_struct. It also adds some debugging macros for when your brain explodes trying to debug your transactional memory enabled kernel. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:32 +08:00
/* Transactional Memory debug */
#ifdef TM_DEBUG_SW
#define TM_DEBUG(x...) printk(KERN_INFO x)
#else
#define TM_DEBUG(x...) do { } while(0)
#endif
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
extern unsigned long _get_SP(void);
powerpc: Don't corrupt transactional state when using FP/VMX in kernel Currently, when we have a process using the transactional memory facilities on POWER8 (that is, the processor is in transactional or suspended state), and the process enters the kernel and the kernel then uses the floating-point or vector (VMX/Altivec) facility, we end up corrupting the user-visible FP/VMX/VSX state. This happens, for example, if a page fault causes a copy-on-write operation, because the copy_page function will use VMX to do the copy on POWER8. The test program below demonstrates the bug. The bug happens because when FP/VMX state for a transactional process is stored in the thread_struct, we store the checkpointed state in .fp_state/.vr_state and the transactional (current) state in .transact_fp/.transact_vr. However, when the kernel wants to use FP/VMX, it calls enable_kernel_fp() or enable_kernel_altivec(), which saves the current state in .fp_state/.vr_state. Furthermore, when we return to the user process we return with FP/VMX/VSX disabled. The next time the process uses FP/VMX/VSX, we don't know which set of state (the current register values, .fp_state/.vr_state, or .transact_fp/.transact_vr) we should be using, since we have no way to tell if we are still in the same transaction, and if not, whether the previous transaction succeeded or failed. Thus it is necessary to strictly adhere to the rule that if FP has been enabled at any point in a transaction, we must keep FP enabled for the user process with the current transactional state in the FP registers, until we detect that it is no longer in a transaction. Similarly for VMX; once enabled it must stay enabled until the process is no longer transactional. In order to keep this rule, we add a new thread_info flag which we test when returning from the kernel to userspace, called TIF_RESTORE_TM. This flag indicates that there is FP/VMX/VSX state to be restored before entering userspace, and when it is set the .tm_orig_msr field in the thread_struct indicates what state needs to be restored. The restoration is done by restore_tm_state(). The TIF_RESTORE_TM bit is set by new giveup_fpu/altivec_maybe_transactional helpers, which are called from enable_kernel_fp/altivec, giveup_vsx, and flush_fp/altivec_to_thread instead of giveup_fpu/altivec. The other thing to be done is to get the transactional FP/VMX/VSX state from .fp_state/.vr_state when doing reclaim, if that state has been saved there by giveup_fpu/altivec_maybe_transactional. Having done this, we set the FP/VMX bit in the thread's MSR after reclaim to indicate that that part of the state is now valid (having been reclaimed from the processor's checkpointed state). Finally, in the signal handling code, we move the clearing of the transactional state bits in the thread's MSR a bit earlier, before calling flush_fp_to_thread(), so that we don't unnecessarily set the TIF_RESTORE_TM bit. This is the test program: /* Michael Neuling 4/12/2013 * * See if the altivec state is leaked out of an aborted transaction due to * kernel vmx copy loops. * * gcc -m64 htm_vmxcopy.c -o htm_vmxcopy * */ /* We don't use all of these, but for reference: */ int main(int argc, char *argv[]) { long double vecin = 1.3; long double vecout; unsigned long pgsize = getpagesize(); int i; int fd; int size = pgsize*16; char tmpfile[] = "/tmp/page_faultXXXXXX"; char buf[pgsize]; char *a; uint64_t aborted = 0; fd = mkstemp(tmpfile); assert(fd >= 0); memset(buf, 0, pgsize); for (i = 0; i < size; i += pgsize) assert(write(fd, buf, pgsize) == pgsize); unlink(tmpfile); a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); assert(a != MAP_FAILED); asm __volatile__( "lxvd2x 40,0,%[vecinptr] ; " // set 40 to initial value TBEGIN "beq 3f ;" TSUSPEND "xxlxor 40,40,40 ; " // set 40 to 0 "std 5, 0(%[map]) ;" // cause kernel vmx copy page TABORT TRESUME TEND "li %[res], 0 ;" "b 5f ;" "3: ;" // Abort handler "li %[res], 1 ;" "5: ;" "stxvd2x 40,0,%[vecoutptr] ; " : [res]"=r"(aborted) : [vecinptr]"r"(&vecin), [vecoutptr]"r"(&vecout), [map]"r"(a) : "memory", "r0", "r3", "r4", "r5", "r6", "r7"); if (aborted && (vecin != vecout)){ printf("FAILED: vector state leaked on abort %f != %f\n", (double)vecin, (double)vecout); exit(1); } munmap(a, size); close(fd); printf("PASSED!\n"); return 0; } Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-13 12:56:29 +08:00
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
powerpc: Simplify TM restore checks Instead of having multiple giveup_*_maybe_transactional() functions, separate out the TM check into a new function called check_if_tm_restore_required(). This will make it easier to optimise the giveup_*() functions in a subsequent patch. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:43:58 +08:00
static void check_if_tm_restore_required(struct task_struct *tsk)
powerpc: Don't corrupt transactional state when using FP/VMX in kernel Currently, when we have a process using the transactional memory facilities on POWER8 (that is, the processor is in transactional or suspended state), and the process enters the kernel and the kernel then uses the floating-point or vector (VMX/Altivec) facility, we end up corrupting the user-visible FP/VMX/VSX state. This happens, for example, if a page fault causes a copy-on-write operation, because the copy_page function will use VMX to do the copy on POWER8. The test program below demonstrates the bug. The bug happens because when FP/VMX state for a transactional process is stored in the thread_struct, we store the checkpointed state in .fp_state/.vr_state and the transactional (current) state in .transact_fp/.transact_vr. However, when the kernel wants to use FP/VMX, it calls enable_kernel_fp() or enable_kernel_altivec(), which saves the current state in .fp_state/.vr_state. Furthermore, when we return to the user process we return with FP/VMX/VSX disabled. The next time the process uses FP/VMX/VSX, we don't know which set of state (the current register values, .fp_state/.vr_state, or .transact_fp/.transact_vr) we should be using, since we have no way to tell if we are still in the same transaction, and if not, whether the previous transaction succeeded or failed. Thus it is necessary to strictly adhere to the rule that if FP has been enabled at any point in a transaction, we must keep FP enabled for the user process with the current transactional state in the FP registers, until we detect that it is no longer in a transaction. Similarly for VMX; once enabled it must stay enabled until the process is no longer transactional. In order to keep this rule, we add a new thread_info flag which we test when returning from the kernel to userspace, called TIF_RESTORE_TM. This flag indicates that there is FP/VMX/VSX state to be restored before entering userspace, and when it is set the .tm_orig_msr field in the thread_struct indicates what state needs to be restored. The restoration is done by restore_tm_state(). The TIF_RESTORE_TM bit is set by new giveup_fpu/altivec_maybe_transactional helpers, which are called from enable_kernel_fp/altivec, giveup_vsx, and flush_fp/altivec_to_thread instead of giveup_fpu/altivec. The other thing to be done is to get the transactional FP/VMX/VSX state from .fp_state/.vr_state when doing reclaim, if that state has been saved there by giveup_fpu/altivec_maybe_transactional. Having done this, we set the FP/VMX bit in the thread's MSR after reclaim to indicate that that part of the state is now valid (having been reclaimed from the processor's checkpointed state). Finally, in the signal handling code, we move the clearing of the transactional state bits in the thread's MSR a bit earlier, before calling flush_fp_to_thread(), so that we don't unnecessarily set the TIF_RESTORE_TM bit. This is the test program: /* Michael Neuling 4/12/2013 * * See if the altivec state is leaked out of an aborted transaction due to * kernel vmx copy loops. * * gcc -m64 htm_vmxcopy.c -o htm_vmxcopy * */ /* We don't use all of these, but for reference: */ int main(int argc, char *argv[]) { long double vecin = 1.3; long double vecout; unsigned long pgsize = getpagesize(); int i; int fd; int size = pgsize*16; char tmpfile[] = "/tmp/page_faultXXXXXX"; char buf[pgsize]; char *a; uint64_t aborted = 0; fd = mkstemp(tmpfile); assert(fd >= 0); memset(buf, 0, pgsize); for (i = 0; i < size; i += pgsize) assert(write(fd, buf, pgsize) == pgsize); unlink(tmpfile); a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); assert(a != MAP_FAILED); asm __volatile__( "lxvd2x 40,0,%[vecinptr] ; " // set 40 to initial value TBEGIN "beq 3f ;" TSUSPEND "xxlxor 40,40,40 ; " // set 40 to 0 "std 5, 0(%[map]) ;" // cause kernel vmx copy page TABORT TRESUME TEND "li %[res], 0 ;" "b 5f ;" "3: ;" // Abort handler "li %[res], 1 ;" "5: ;" "stxvd2x 40,0,%[vecoutptr] ; " : [res]"=r"(aborted) : [vecinptr]"r"(&vecin), [vecoutptr]"r"(&vecout), [map]"r"(a) : "memory", "r0", "r3", "r4", "r5", "r6", "r7"); if (aborted && (vecin != vecout)){ printf("FAILED: vector state leaked on abort %f != %f\n", (double)vecin, (double)vecout); exit(1); } munmap(a, size); close(fd); printf("PASSED!\n"); return 0; } Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-13 12:56:29 +08:00
{
/*
* If we are saving the current thread's registers, and the
* thread is in a transactional state, set the TIF_RESTORE_TM
* bit so that we know to restore the registers before
* returning to userspace.
*/
if (tsk == current && tsk->thread.regs &&
MSR_TM_ACTIVE(tsk->thread.regs->msr) &&
!test_thread_flag(TIF_RESTORE_TM)) {
powerpc/tm: Drop tm_orig_msr from thread_struct Currently tm_orig_msr is getting used during process context switch only. Then there is ckpt_regs which saves the checkpointed userspace context The MSR slot contained in ckpt_regs structure can be used during process context switch instead of tm_orig_msr, thus allowing us to drop it from thread_struct structure. This patch does that change. Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-07-06 18:54:10 +08:00
tsk->thread.ckpt_regs.msr = tsk->thread.regs->msr;
powerpc: Don't corrupt transactional state when using FP/VMX in kernel Currently, when we have a process using the transactional memory facilities on POWER8 (that is, the processor is in transactional or suspended state), and the process enters the kernel and the kernel then uses the floating-point or vector (VMX/Altivec) facility, we end up corrupting the user-visible FP/VMX/VSX state. This happens, for example, if a page fault causes a copy-on-write operation, because the copy_page function will use VMX to do the copy on POWER8. The test program below demonstrates the bug. The bug happens because when FP/VMX state for a transactional process is stored in the thread_struct, we store the checkpointed state in .fp_state/.vr_state and the transactional (current) state in .transact_fp/.transact_vr. However, when the kernel wants to use FP/VMX, it calls enable_kernel_fp() or enable_kernel_altivec(), which saves the current state in .fp_state/.vr_state. Furthermore, when we return to the user process we return with FP/VMX/VSX disabled. The next time the process uses FP/VMX/VSX, we don't know which set of state (the current register values, .fp_state/.vr_state, or .transact_fp/.transact_vr) we should be using, since we have no way to tell if we are still in the same transaction, and if not, whether the previous transaction succeeded or failed. Thus it is necessary to strictly adhere to the rule that if FP has been enabled at any point in a transaction, we must keep FP enabled for the user process with the current transactional state in the FP registers, until we detect that it is no longer in a transaction. Similarly for VMX; once enabled it must stay enabled until the process is no longer transactional. In order to keep this rule, we add a new thread_info flag which we test when returning from the kernel to userspace, called TIF_RESTORE_TM. This flag indicates that there is FP/VMX/VSX state to be restored before entering userspace, and when it is set the .tm_orig_msr field in the thread_struct indicates what state needs to be restored. The restoration is done by restore_tm_state(). The TIF_RESTORE_TM bit is set by new giveup_fpu/altivec_maybe_transactional helpers, which are called from enable_kernel_fp/altivec, giveup_vsx, and flush_fp/altivec_to_thread instead of giveup_fpu/altivec. The other thing to be done is to get the transactional FP/VMX/VSX state from .fp_state/.vr_state when doing reclaim, if that state has been saved there by giveup_fpu/altivec_maybe_transactional. Having done this, we set the FP/VMX bit in the thread's MSR after reclaim to indicate that that part of the state is now valid (having been reclaimed from the processor's checkpointed state). Finally, in the signal handling code, we move the clearing of the transactional state bits in the thread's MSR a bit earlier, before calling flush_fp_to_thread(), so that we don't unnecessarily set the TIF_RESTORE_TM bit. This is the test program: /* Michael Neuling 4/12/2013 * * See if the altivec state is leaked out of an aborted transaction due to * kernel vmx copy loops. * * gcc -m64 htm_vmxcopy.c -o htm_vmxcopy * */ /* We don't use all of these, but for reference: */ int main(int argc, char *argv[]) { long double vecin = 1.3; long double vecout; unsigned long pgsize = getpagesize(); int i; int fd; int size = pgsize*16; char tmpfile[] = "/tmp/page_faultXXXXXX"; char buf[pgsize]; char *a; uint64_t aborted = 0; fd = mkstemp(tmpfile); assert(fd >= 0); memset(buf, 0, pgsize); for (i = 0; i < size; i += pgsize) assert(write(fd, buf, pgsize) == pgsize); unlink(tmpfile); a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); assert(a != MAP_FAILED); asm __volatile__( "lxvd2x 40,0,%[vecinptr] ; " // set 40 to initial value TBEGIN "beq 3f ;" TSUSPEND "xxlxor 40,40,40 ; " // set 40 to 0 "std 5, 0(%[map]) ;" // cause kernel vmx copy page TABORT TRESUME TEND "li %[res], 0 ;" "b 5f ;" "3: ;" // Abort handler "li %[res], 1 ;" "5: ;" "stxvd2x 40,0,%[vecoutptr] ; " : [res]"=r"(aborted) : [vecinptr]"r"(&vecin), [vecoutptr]"r"(&vecout), [map]"r"(a) : "memory", "r0", "r3", "r4", "r5", "r6", "r7"); if (aborted && (vecin != vecout)){ printf("FAILED: vector state leaked on abort %f != %f\n", (double)vecin, (double)vecout); exit(1); } munmap(a, size); close(fd); printf("PASSED!\n"); return 0; } Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-13 12:56:29 +08:00
set_thread_flag(TIF_RESTORE_TM);
}
}
powerpc: Always restore FPU/VEC/VSX if hardware transactional memory in use Comment from arch/powerpc/kernel/process.c:967: If userspace is inside a transaction (whether active or suspended) and FP/VMX/VSX instructions have ever been enabled inside that transaction, then we have to keep them enabled and keep the FP/VMX/VSX state loaded while ever the transaction continues. The reason is that if we didn't, and subsequently got a FP/VMX/VSX unavailable interrupt inside a transaction, we don't know whether it's the same transaction, and thus we don't know which of the checkpointed state and the ransactional state to use. restore_math() restore_fp() and restore_altivec() currently may not restore the registers. It doesn't appear that this is more serious than a performance penalty. If the math registers aren't restored the userspace thread will still be run with the facility disabled. Userspace will not be able to read invalid values. On the first access it will take an facility unavailable exception and the kernel will detected an active transaction, at which point it will abort the transaction. There is the possibility for a pathological case preventing any progress by transactions, however, transactions are never guaranteed to make progress. Fixes: 70fe3d9 ("powerpc: Restore FPU/VEC/VSX if previously used") Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:08 +08:00
static inline bool msr_tm_active(unsigned long msr)
{
return MSR_TM_ACTIVE(msr);
}
powerpc: Don't corrupt transactional state when using FP/VMX in kernel Currently, when we have a process using the transactional memory facilities on POWER8 (that is, the processor is in transactional or suspended state), and the process enters the kernel and the kernel then uses the floating-point or vector (VMX/Altivec) facility, we end up corrupting the user-visible FP/VMX/VSX state. This happens, for example, if a page fault causes a copy-on-write operation, because the copy_page function will use VMX to do the copy on POWER8. The test program below demonstrates the bug. The bug happens because when FP/VMX state for a transactional process is stored in the thread_struct, we store the checkpointed state in .fp_state/.vr_state and the transactional (current) state in .transact_fp/.transact_vr. However, when the kernel wants to use FP/VMX, it calls enable_kernel_fp() or enable_kernel_altivec(), which saves the current state in .fp_state/.vr_state. Furthermore, when we return to the user process we return with FP/VMX/VSX disabled. The next time the process uses FP/VMX/VSX, we don't know which set of state (the current register values, .fp_state/.vr_state, or .transact_fp/.transact_vr) we should be using, since we have no way to tell if we are still in the same transaction, and if not, whether the previous transaction succeeded or failed. Thus it is necessary to strictly adhere to the rule that if FP has been enabled at any point in a transaction, we must keep FP enabled for the user process with the current transactional state in the FP registers, until we detect that it is no longer in a transaction. Similarly for VMX; once enabled it must stay enabled until the process is no longer transactional. In order to keep this rule, we add a new thread_info flag which we test when returning from the kernel to userspace, called TIF_RESTORE_TM. This flag indicates that there is FP/VMX/VSX state to be restored before entering userspace, and when it is set the .tm_orig_msr field in the thread_struct indicates what state needs to be restored. The restoration is done by restore_tm_state(). The TIF_RESTORE_TM bit is set by new giveup_fpu/altivec_maybe_transactional helpers, which are called from enable_kernel_fp/altivec, giveup_vsx, and flush_fp/altivec_to_thread instead of giveup_fpu/altivec. The other thing to be done is to get the transactional FP/VMX/VSX state from .fp_state/.vr_state when doing reclaim, if that state has been saved there by giveup_fpu/altivec_maybe_transactional. Having done this, we set the FP/VMX bit in the thread's MSR after reclaim to indicate that that part of the state is now valid (having been reclaimed from the processor's checkpointed state). Finally, in the signal handling code, we move the clearing of the transactional state bits in the thread's MSR a bit earlier, before calling flush_fp_to_thread(), so that we don't unnecessarily set the TIF_RESTORE_TM bit. This is the test program: /* Michael Neuling 4/12/2013 * * See if the altivec state is leaked out of an aborted transaction due to * kernel vmx copy loops. * * gcc -m64 htm_vmxcopy.c -o htm_vmxcopy * */ /* We don't use all of these, but for reference: */ int main(int argc, char *argv[]) { long double vecin = 1.3; long double vecout; unsigned long pgsize = getpagesize(); int i; int fd; int size = pgsize*16; char tmpfile[] = "/tmp/page_faultXXXXXX"; char buf[pgsize]; char *a; uint64_t aborted = 0; fd = mkstemp(tmpfile); assert(fd >= 0); memset(buf, 0, pgsize); for (i = 0; i < size; i += pgsize) assert(write(fd, buf, pgsize) == pgsize); unlink(tmpfile); a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); assert(a != MAP_FAILED); asm __volatile__( "lxvd2x 40,0,%[vecinptr] ; " // set 40 to initial value TBEGIN "beq 3f ;" TSUSPEND "xxlxor 40,40,40 ; " // set 40 to 0 "std 5, 0(%[map]) ;" // cause kernel vmx copy page TABORT TRESUME TEND "li %[res], 0 ;" "b 5f ;" "3: ;" // Abort handler "li %[res], 1 ;" "5: ;" "stxvd2x 40,0,%[vecoutptr] ; " : [res]"=r"(aborted) : [vecinptr]"r"(&vecin), [vecoutptr]"r"(&vecout), [map]"r"(a) : "memory", "r0", "r3", "r4", "r5", "r6", "r7"); if (aborted && (vecin != vecout)){ printf("FAILED: vector state leaked on abort %f != %f\n", (double)vecin, (double)vecout); exit(1); } munmap(a, size); close(fd); printf("PASSED!\n"); return 0; } Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-13 12:56:29 +08:00
#else
powerpc: Always restore FPU/VEC/VSX if hardware transactional memory in use Comment from arch/powerpc/kernel/process.c:967: If userspace is inside a transaction (whether active or suspended) and FP/VMX/VSX instructions have ever been enabled inside that transaction, then we have to keep them enabled and keep the FP/VMX/VSX state loaded while ever the transaction continues. The reason is that if we didn't, and subsequently got a FP/VMX/VSX unavailable interrupt inside a transaction, we don't know whether it's the same transaction, and thus we don't know which of the checkpointed state and the ransactional state to use. restore_math() restore_fp() and restore_altivec() currently may not restore the registers. It doesn't appear that this is more serious than a performance penalty. If the math registers aren't restored the userspace thread will still be run with the facility disabled. Userspace will not be able to read invalid values. On the first access it will take an facility unavailable exception and the kernel will detected an active transaction, at which point it will abort the transaction. There is the possibility for a pathological case preventing any progress by transactions, however, transactions are never guaranteed to make progress. Fixes: 70fe3d9 ("powerpc: Restore FPU/VEC/VSX if previously used") Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:08 +08:00
static inline bool msr_tm_active(unsigned long msr) { return false; }
powerpc: Simplify TM restore checks Instead of having multiple giveup_*_maybe_transactional() functions, separate out the TM check into a new function called check_if_tm_restore_required(). This will make it easier to optimise the giveup_*() functions in a subsequent patch. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:43:58 +08:00
static inline void check_if_tm_restore_required(struct task_struct *tsk) { }
powerpc: Don't corrupt transactional state when using FP/VMX in kernel Currently, when we have a process using the transactional memory facilities on POWER8 (that is, the processor is in transactional or suspended state), and the process enters the kernel and the kernel then uses the floating-point or vector (VMX/Altivec) facility, we end up corrupting the user-visible FP/VMX/VSX state. This happens, for example, if a page fault causes a copy-on-write operation, because the copy_page function will use VMX to do the copy on POWER8. The test program below demonstrates the bug. The bug happens because when FP/VMX state for a transactional process is stored in the thread_struct, we store the checkpointed state in .fp_state/.vr_state and the transactional (current) state in .transact_fp/.transact_vr. However, when the kernel wants to use FP/VMX, it calls enable_kernel_fp() or enable_kernel_altivec(), which saves the current state in .fp_state/.vr_state. Furthermore, when we return to the user process we return with FP/VMX/VSX disabled. The next time the process uses FP/VMX/VSX, we don't know which set of state (the current register values, .fp_state/.vr_state, or .transact_fp/.transact_vr) we should be using, since we have no way to tell if we are still in the same transaction, and if not, whether the previous transaction succeeded or failed. Thus it is necessary to strictly adhere to the rule that if FP has been enabled at any point in a transaction, we must keep FP enabled for the user process with the current transactional state in the FP registers, until we detect that it is no longer in a transaction. Similarly for VMX; once enabled it must stay enabled until the process is no longer transactional. In order to keep this rule, we add a new thread_info flag which we test when returning from the kernel to userspace, called TIF_RESTORE_TM. This flag indicates that there is FP/VMX/VSX state to be restored before entering userspace, and when it is set the .tm_orig_msr field in the thread_struct indicates what state needs to be restored. The restoration is done by restore_tm_state(). The TIF_RESTORE_TM bit is set by new giveup_fpu/altivec_maybe_transactional helpers, which are called from enable_kernel_fp/altivec, giveup_vsx, and flush_fp/altivec_to_thread instead of giveup_fpu/altivec. The other thing to be done is to get the transactional FP/VMX/VSX state from .fp_state/.vr_state when doing reclaim, if that state has been saved there by giveup_fpu/altivec_maybe_transactional. Having done this, we set the FP/VMX bit in the thread's MSR after reclaim to indicate that that part of the state is now valid (having been reclaimed from the processor's checkpointed state). Finally, in the signal handling code, we move the clearing of the transactional state bits in the thread's MSR a bit earlier, before calling flush_fp_to_thread(), so that we don't unnecessarily set the TIF_RESTORE_TM bit. This is the test program: /* Michael Neuling 4/12/2013 * * See if the altivec state is leaked out of an aborted transaction due to * kernel vmx copy loops. * * gcc -m64 htm_vmxcopy.c -o htm_vmxcopy * */ /* We don't use all of these, but for reference: */ int main(int argc, char *argv[]) { long double vecin = 1.3; long double vecout; unsigned long pgsize = getpagesize(); int i; int fd; int size = pgsize*16; char tmpfile[] = "/tmp/page_faultXXXXXX"; char buf[pgsize]; char *a; uint64_t aborted = 0; fd = mkstemp(tmpfile); assert(fd >= 0); memset(buf, 0, pgsize); for (i = 0; i < size; i += pgsize) assert(write(fd, buf, pgsize) == pgsize); unlink(tmpfile); a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); assert(a != MAP_FAILED); asm __volatile__( "lxvd2x 40,0,%[vecinptr] ; " // set 40 to initial value TBEGIN "beq 3f ;" TSUSPEND "xxlxor 40,40,40 ; " // set 40 to 0 "std 5, 0(%[map]) ;" // cause kernel vmx copy page TABORT TRESUME TEND "li %[res], 0 ;" "b 5f ;" "3: ;" // Abort handler "li %[res], 1 ;" "5: ;" "stxvd2x 40,0,%[vecoutptr] ; " : [res]"=r"(aborted) : [vecinptr]"r"(&vecin), [vecoutptr]"r"(&vecout), [map]"r"(a) : "memory", "r0", "r3", "r4", "r5", "r6", "r7"); if (aborted && (vecin != vecout)){ printf("FAILED: vector state leaked on abort %f != %f\n", (double)vecin, (double)vecout); exit(1); } munmap(a, size); close(fd); printf("PASSED!\n"); return 0; } Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-13 12:56:29 +08:00
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
powerpc: Add ppc_strict_facility_enable boot option Add a boot option that strictly manages the MSR unavailable bits. This catches kernel uses of FP/Altivec/SPE that would otherwise corrupt user state. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:06 +08:00
bool strict_msr_control;
EXPORT_SYMBOL(strict_msr_control);
static int __init enable_strict_msr_control(char *str)
{
strict_msr_control = true;
pr_info("Enabling strict facility control\n");
return 0;
}
early_param("ppc_strict_facility_enable", enable_strict_msr_control);
powerpc: Return the new MSR from msr_check_and_set() msr_check_and_set() always performs a mfmsr() to determine if it needs to perform an mtmsr(), as mfmsr() can be a costly operation msr_check_and_set() could return the MSR now on the CPU to avoid callers of msr_check_and_set having to make their own mfmsr() call. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:10 +08:00
unsigned long msr_check_and_set(unsigned long bits)
powerpc: Move part of giveup_fpu,altivec,spe into c Move the MSR modification into new c functions. Removing it from the low level functions will allow us to avoid costly MSR writes by batching them up. Move the check_if_tm_restore_required() check into these new functions. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:01 +08:00
{
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
unsigned long oldmsr = mfmsr();
unsigned long newmsr;
powerpc: Move part of giveup_fpu,altivec,spe into c Move the MSR modification into new c functions. Removing it from the low level functions will allow us to avoid costly MSR writes by batching them up. Move the check_if_tm_restore_required() check into these new functions. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:01 +08:00
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
newmsr = oldmsr | bits;
powerpc: Move part of giveup_fpu,altivec,spe into c Move the MSR modification into new c functions. Removing it from the low level functions will allow us to avoid costly MSR writes by batching them up. Move the check_if_tm_restore_required() check into these new functions. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:01 +08:00
#ifdef CONFIG_VSX
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
powerpc: Move part of giveup_fpu,altivec,spe into c Move the MSR modification into new c functions. Removing it from the low level functions will allow us to avoid costly MSR writes by batching them up. Move the check_if_tm_restore_required() check into these new functions. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:01 +08:00
newmsr |= MSR_VSX;
#endif
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
powerpc: Move part of giveup_fpu,altivec,spe into c Move the MSR modification into new c functions. Removing it from the low level functions will allow us to avoid costly MSR writes by batching them up. Move the check_if_tm_restore_required() check into these new functions. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:01 +08:00
if (oldmsr != newmsr)
mtmsr_isync(newmsr);
powerpc: Return the new MSR from msr_check_and_set() msr_check_and_set() always performs a mfmsr() to determine if it needs to perform an mtmsr(), as mfmsr() can be a costly operation msr_check_and_set() could return the MSR now on the CPU to avoid callers of msr_check_and_set having to make their own mfmsr() call. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:10 +08:00
return newmsr;
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
}
powerpc: Move part of giveup_fpu,altivec,spe into c Move the MSR modification into new c functions. Removing it from the low level functions will allow us to avoid costly MSR writes by batching them up. Move the check_if_tm_restore_required() check into these new functions. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:01 +08:00
powerpc: Add ppc_strict_facility_enable boot option Add a boot option that strictly manages the MSR unavailable bits. This catches kernel uses of FP/Altivec/SPE that would otherwise corrupt user state. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:06 +08:00
void __msr_check_and_clear(unsigned long bits)
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
{
unsigned long oldmsr = mfmsr();
unsigned long newmsr;
newmsr = oldmsr & ~bits;
#ifdef CONFIG_VSX
if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
newmsr &= ~MSR_VSX;
#endif
if (oldmsr != newmsr)
mtmsr_isync(newmsr);
}
powerpc: Add ppc_strict_facility_enable boot option Add a boot option that strictly manages the MSR unavailable bits. This catches kernel uses of FP/Altivec/SPE that would otherwise corrupt user state. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:06 +08:00
EXPORT_SYMBOL(__msr_check_and_clear);
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
#ifdef CONFIG_PPC_FPU
powerpc: Add the ability to save FPU without giving it up This patch adds the ability to be able to save the FPU registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch optimises the thread copy path (as a result of a fork() or clone()) so that the parent thread can return to userspace with hot registers avoiding a possibly pointless reload of FPU register state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:49 +08:00
void __giveup_fpu(struct task_struct *tsk)
{
powerpc: Avoid load hit store in __giveup_fpu() and __giveup_altivec() In both __giveup_fpu() and __giveup_altivec() we make two modifications to tsk->thread.regs->msr. gcc decides to do a read/modify/write of each change, so we end up with a load hit store: ld r9,264(r10) rldicl r9,r9,50,1 rotldi r9,r9,14 std r9,264(r10) ... ld r9,264(r10) rldicl r9,r9,40,1 rotldi r9,r9,24 std r9,264(r10) Fix this by using a temporary. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-29 20:03:50 +08:00
unsigned long msr;
powerpc: Add the ability to save FPU without giving it up This patch adds the ability to be able to save the FPU registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch optimises the thread copy path (as a result of a fork() or clone()) so that the parent thread can return to userspace with hot registers avoiding a possibly pointless reload of FPU register state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:49 +08:00
save_fpu(tsk);
powerpc: Avoid load hit store in __giveup_fpu() and __giveup_altivec() In both __giveup_fpu() and __giveup_altivec() we make two modifications to tsk->thread.regs->msr. gcc decides to do a read/modify/write of each change, so we end up with a load hit store: ld r9,264(r10) rldicl r9,r9,50,1 rotldi r9,r9,14 std r9,264(r10) ... ld r9,264(r10) rldicl r9,r9,40,1 rotldi r9,r9,24 std r9,264(r10) Fix this by using a temporary. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-29 20:03:50 +08:00
msr = tsk->thread.regs->msr;
msr &= ~MSR_FP;
powerpc: Add the ability to save FPU without giving it up This patch adds the ability to be able to save the FPU registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch optimises the thread copy path (as a result of a fork() or clone()) so that the parent thread can return to userspace with hot registers avoiding a possibly pointless reload of FPU register state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:49 +08:00
#ifdef CONFIG_VSX
if (cpu_has_feature(CPU_FTR_VSX))
powerpc: Avoid load hit store in __giveup_fpu() and __giveup_altivec() In both __giveup_fpu() and __giveup_altivec() we make two modifications to tsk->thread.regs->msr. gcc decides to do a read/modify/write of each change, so we end up with a load hit store: ld r9,264(r10) rldicl r9,r9,50,1 rotldi r9,r9,14 std r9,264(r10) ... ld r9,264(r10) rldicl r9,r9,40,1 rotldi r9,r9,24 std r9,264(r10) Fix this by using a temporary. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-29 20:03:50 +08:00
msr &= ~MSR_VSX;
powerpc: Add the ability to save FPU without giving it up This patch adds the ability to be able to save the FPU registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch optimises the thread copy path (as a result of a fork() or clone()) so that the parent thread can return to userspace with hot registers avoiding a possibly pointless reload of FPU register state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:49 +08:00
#endif
powerpc: Avoid load hit store in __giveup_fpu() and __giveup_altivec() In both __giveup_fpu() and __giveup_altivec() we make two modifications to tsk->thread.regs->msr. gcc decides to do a read/modify/write of each change, so we end up with a load hit store: ld r9,264(r10) rldicl r9,r9,50,1 rotldi r9,r9,14 std r9,264(r10) ... ld r9,264(r10) rldicl r9,r9,40,1 rotldi r9,r9,24 std r9,264(r10) Fix this by using a temporary. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-29 20:03:50 +08:00
tsk->thread.regs->msr = msr;
powerpc: Add the ability to save FPU without giving it up This patch adds the ability to be able to save the FPU registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch optimises the thread copy path (as a result of a fork() or clone()) so that the parent thread can return to userspace with hot registers avoiding a possibly pointless reload of FPU register state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:49 +08:00
}
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
void giveup_fpu(struct task_struct *tsk)
{
check_if_tm_restore_required(tsk);
msr_check_and_set(MSR_FP);
powerpc: Move part of giveup_fpu,altivec,spe into c Move the MSR modification into new c functions. Removing it from the low level functions will allow us to avoid costly MSR writes by batching them up. Move the check_if_tm_restore_required() check into these new functions. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:01 +08:00
__giveup_fpu(tsk);
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
msr_check_and_clear(MSR_FP);
powerpc: Move part of giveup_fpu,altivec,spe into c Move the MSR modification into new c functions. Removing it from the low level functions will allow us to avoid costly MSR writes by batching them up. Move the check_if_tm_restore_required() check into these new functions. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:01 +08:00
}
EXPORT_SYMBOL(giveup_fpu);
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
/*
* Make sure the floating-point register state in the
* the thread_struct is up to date for task tsk.
*/
void flush_fp_to_thread(struct task_struct *tsk)
{
if (tsk->thread.regs) {
/*
* We need to disable preemption here because if we didn't,
* another process could get scheduled after the regs->msr
* test but before we have finished saving the FP registers
* to the thread_struct. That process could take over the
* FPU, and then when we get scheduled again we would store
* bogus values for the remaining FP registers.
*/
preempt_disable();
if (tsk->thread.regs->msr & MSR_FP) {
/*
* This should only ever be called for current or
* for a stopped child process. Since we save away
powerpc: Remove UP only lazy floating point and vector optimisations The UP only lazy floating point and vector optimisations were written back when SMP was not common, and neither glibc nor gcc used vector instructions. Now SMP is very common, glibc aggressively uses vector instructions and gcc autovectorises. We want to add new optimisations that apply to both UP and SMP, but in preparation for that remove these UP only optimisations. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:43:57 +08:00
* the FP register state on context switch,
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
* there is something wrong if a stopped child appears
* to still have its FP state in the CPU registers.
*/
BUG_ON(tsk != current);
powerpc: Simplify TM restore checks Instead of having multiple giveup_*_maybe_transactional() functions, separate out the TM check into a new function called check_if_tm_restore_required(). This will make it easier to optimise the giveup_*() functions in a subsequent patch. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:43:58 +08:00
giveup_fpu(tsk);
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
}
preempt_enable();
}
}
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
EXPORT_SYMBOL_GPL(flush_fp_to_thread);
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
void enable_kernel_fp(void)
{
powerpc: Never giveup a reclaimed thread when enabling kernel {fp, altivec, vsx} After a thread is reclaimed from its active or suspended transactional state the checkpointed state exists on CPU, this state (along with the live/transactional state) has been saved in its entirety by the reclaiming process. There exists a sequence of events that would cause the kernel to call one of enable_kernel_fp(), enable_kernel_altivec() or enable_kernel_vsx() after a thread has been reclaimed. These functions save away any user state on the CPU so that the kernel can use the registers. Not only is this saving away unnecessary at this point, it is actually incorrect. It causes a save of the checkpointed state to the live structures within the thread struct thus destroying the true live state for that thread. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:11 +08:00
unsigned long cpumsr;
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
WARN_ON(preemptible());
powerpc: Never giveup a reclaimed thread when enabling kernel {fp, altivec, vsx} After a thread is reclaimed from its active or suspended transactional state the checkpointed state exists on CPU, this state (along with the live/transactional state) has been saved in its entirety by the reclaiming process. There exists a sequence of events that would cause the kernel to call one of enable_kernel_fp(), enable_kernel_altivec() or enable_kernel_vsx() after a thread has been reclaimed. These functions save away any user state on the CPU so that the kernel can use the registers. Not only is this saving away unnecessary at this point, it is actually incorrect. It causes a save of the checkpointed state to the live structures within the thread struct thus destroying the true live state for that thread. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:11 +08:00
cpumsr = msr_check_and_set(MSR_FP);
powerpc: Create mtmsrd_isync() mtmsrd_isync() will do an mtmsrd followed by an isync on older processors. On newer processors we avoid the isync via a feature fixup. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:43:59 +08:00
powerpc: Call check_if_tm_restore_required() in enable_kernel_*() Commit a0e72cf12b1a ("powerpc: Create msr_check_and_{set,clear}()") removed a call to check_if_tm_restore_required() in the enable_kernel_*() functions. Add them back in. Fixes: a0e72cf12b1a ("powerpc: Create msr_check_and_{set,clear}()") Reported-by: Rashmica Gupta <rashmicy@gmail.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-10 17:04:05 +08:00
if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) {
check_if_tm_restore_required(current);
powerpc: Never giveup a reclaimed thread when enabling kernel {fp, altivec, vsx} After a thread is reclaimed from its active or suspended transactional state the checkpointed state exists on CPU, this state (along with the live/transactional state) has been saved in its entirety by the reclaiming process. There exists a sequence of events that would cause the kernel to call one of enable_kernel_fp(), enable_kernel_altivec() or enable_kernel_vsx() after a thread has been reclaimed. These functions save away any user state on the CPU so that the kernel can use the registers. Not only is this saving away unnecessary at this point, it is actually incorrect. It causes a save of the checkpointed state to the live structures within the thread struct thus destroying the true live state for that thread. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:11 +08:00
/*
* If a thread has already been reclaimed then the
* checkpointed registers are on the CPU but have definitely
* been saved by the reclaim code. Don't need to and *cannot*
* giveup as this would save to the 'live' structure not the
* checkpointed structure.
*/
if(!msr_tm_active(cpumsr) && msr_tm_active(current->thread.regs->msr))
return;
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
__giveup_fpu(current);
powerpc: Call check_if_tm_restore_required() in enable_kernel_*() Commit a0e72cf12b1a ("powerpc: Create msr_check_and_{set,clear}()") removed a call to check_if_tm_restore_required() in the enable_kernel_*() functions. Add them back in. Fixes: a0e72cf12b1a ("powerpc: Create msr_check_and_{set,clear}()") Reported-by: Rashmica Gupta <rashmicy@gmail.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-10 17:04:05 +08:00
}
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
}
EXPORT_SYMBOL(enable_kernel_fp);
powerpc: Restore FPU/VEC/VSX if previously used Currently the FPU, VEC and VSX facilities are lazily loaded. This is not a problem unless a process is using these facilities. Modern versions of GCC are very good at automatically vectorising code, new and modernised workloads make use of floating point and vector facilities, even the kernel makes use of vectorised memcpy. All this combined greatly increases the cost of a syscall since the kernel uses the facilities sometimes even in syscall fast-path making it increasingly common for a thread to take an *_unavailable exception soon after a syscall, not to mention potentially taking all three. The obvious overcompensation to this problem is to simply always load all the facilities on every exit to userspace. Loading up all FPU, VEC and VSX registers every time can be expensive and if a workload does avoid using them, it should not be forced to incur this penalty. An 8bit counter is used to detect if the registers have been used in the past and the registers are always loaded until the value wraps to back to zero. Several versions of the assembly in entry_64.S were tested: 1. Always calling C. 2. Performing a common case check and then calling C. 3. A complex check in asm. After some benchmarking it was determined that avoiding C in the common case is a performance benefit (option 2). The full check in asm (option 3) greatly complicated that codepath for a negligible performance gain and the trade-off was deemed not worth it. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> [mpe: Move load_vec in the struct to fill an existing hole, reword change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> fixup
2016-02-29 14:53:47 +08:00
static int restore_fp(struct task_struct *tsk) {
powerpc: Always restore FPU/VEC/VSX if hardware transactional memory in use Comment from arch/powerpc/kernel/process.c:967: If userspace is inside a transaction (whether active or suspended) and FP/VMX/VSX instructions have ever been enabled inside that transaction, then we have to keep them enabled and keep the FP/VMX/VSX state loaded while ever the transaction continues. The reason is that if we didn't, and subsequently got a FP/VMX/VSX unavailable interrupt inside a transaction, we don't know whether it's the same transaction, and thus we don't know which of the checkpointed state and the ransactional state to use. restore_math() restore_fp() and restore_altivec() currently may not restore the registers. It doesn't appear that this is more serious than a performance penalty. If the math registers aren't restored the userspace thread will still be run with the facility disabled. Userspace will not be able to read invalid values. On the first access it will take an facility unavailable exception and the kernel will detected an active transaction, at which point it will abort the transaction. There is the possibility for a pathological case preventing any progress by transactions, however, transactions are never guaranteed to make progress. Fixes: 70fe3d9 ("powerpc: Restore FPU/VEC/VSX if previously used") Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:08 +08:00
if (tsk->thread.load_fp || msr_tm_active(tsk->thread.regs->msr)) {
powerpc: Restore FPU/VEC/VSX if previously used Currently the FPU, VEC and VSX facilities are lazily loaded. This is not a problem unless a process is using these facilities. Modern versions of GCC are very good at automatically vectorising code, new and modernised workloads make use of floating point and vector facilities, even the kernel makes use of vectorised memcpy. All this combined greatly increases the cost of a syscall since the kernel uses the facilities sometimes even in syscall fast-path making it increasingly common for a thread to take an *_unavailable exception soon after a syscall, not to mention potentially taking all three. The obvious overcompensation to this problem is to simply always load all the facilities on every exit to userspace. Loading up all FPU, VEC and VSX registers every time can be expensive and if a workload does avoid using them, it should not be forced to incur this penalty. An 8bit counter is used to detect if the registers have been used in the past and the registers are always loaded until the value wraps to back to zero. Several versions of the assembly in entry_64.S were tested: 1. Always calling C. 2. Performing a common case check and then calling C. 3. A complex check in asm. After some benchmarking it was determined that avoiding C in the common case is a performance benefit (option 2). The full check in asm (option 3) greatly complicated that codepath for a negligible performance gain and the trade-off was deemed not worth it. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> [mpe: Move load_vec in the struct to fill an existing hole, reword change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> fixup
2016-02-29 14:53:47 +08:00
load_fp_state(&current->thread.fp_state);
current->thread.load_fp++;
return 1;
}
return 0;
}
#else
static int restore_fp(struct task_struct *tsk) { return 0; }
powerpc: clean up asm/switch_to.h Remove a bunch of unnecessary fallback functions and group things in a more logical way. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:11 +08:00
#endif /* CONFIG_PPC_FPU */
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
#ifdef CONFIG_ALTIVEC
powerpc: Restore FPU/VEC/VSX if previously used Currently the FPU, VEC and VSX facilities are lazily loaded. This is not a problem unless a process is using these facilities. Modern versions of GCC are very good at automatically vectorising code, new and modernised workloads make use of floating point and vector facilities, even the kernel makes use of vectorised memcpy. All this combined greatly increases the cost of a syscall since the kernel uses the facilities sometimes even in syscall fast-path making it increasingly common for a thread to take an *_unavailable exception soon after a syscall, not to mention potentially taking all three. The obvious overcompensation to this problem is to simply always load all the facilities on every exit to userspace. Loading up all FPU, VEC and VSX registers every time can be expensive and if a workload does avoid using them, it should not be forced to incur this penalty. An 8bit counter is used to detect if the registers have been used in the past and the registers are always loaded until the value wraps to back to zero. Several versions of the assembly in entry_64.S were tested: 1. Always calling C. 2. Performing a common case check and then calling C. 3. A complex check in asm. After some benchmarking it was determined that avoiding C in the common case is a performance benefit (option 2). The full check in asm (option 3) greatly complicated that codepath for a negligible performance gain and the trade-off was deemed not worth it. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> [mpe: Move load_vec in the struct to fill an existing hole, reword change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> fixup
2016-02-29 14:53:47 +08:00
#define loadvec(thr) ((thr).load_vec)
powerpc: Add the ability to save Altivec without giving it up This patch adds the ability to be able to save the VEC registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch builds on a previous optimisation for the FPU registers in the thread copy path to avoid a possibly pointless reload of VEC state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:50 +08:00
static void __giveup_altivec(struct task_struct *tsk)
{
powerpc: Avoid load hit store in __giveup_fpu() and __giveup_altivec() In both __giveup_fpu() and __giveup_altivec() we make two modifications to tsk->thread.regs->msr. gcc decides to do a read/modify/write of each change, so we end up with a load hit store: ld r9,264(r10) rldicl r9,r9,50,1 rotldi r9,r9,14 std r9,264(r10) ... ld r9,264(r10) rldicl r9,r9,40,1 rotldi r9,r9,24 std r9,264(r10) Fix this by using a temporary. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-29 20:03:50 +08:00
unsigned long msr;
powerpc: Add the ability to save Altivec without giving it up This patch adds the ability to be able to save the VEC registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch builds on a previous optimisation for the FPU registers in the thread copy path to avoid a possibly pointless reload of VEC state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:50 +08:00
save_altivec(tsk);
powerpc: Avoid load hit store in __giveup_fpu() and __giveup_altivec() In both __giveup_fpu() and __giveup_altivec() we make two modifications to tsk->thread.regs->msr. gcc decides to do a read/modify/write of each change, so we end up with a load hit store: ld r9,264(r10) rldicl r9,r9,50,1 rotldi r9,r9,14 std r9,264(r10) ... ld r9,264(r10) rldicl r9,r9,40,1 rotldi r9,r9,24 std r9,264(r10) Fix this by using a temporary. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-29 20:03:50 +08:00
msr = tsk->thread.regs->msr;
msr &= ~MSR_VEC;
powerpc: Add the ability to save Altivec without giving it up This patch adds the ability to be able to save the VEC registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch builds on a previous optimisation for the FPU registers in the thread copy path to avoid a possibly pointless reload of VEC state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:50 +08:00
#ifdef CONFIG_VSX
if (cpu_has_feature(CPU_FTR_VSX))
powerpc: Avoid load hit store in __giveup_fpu() and __giveup_altivec() In both __giveup_fpu() and __giveup_altivec() we make two modifications to tsk->thread.regs->msr. gcc decides to do a read/modify/write of each change, so we end up with a load hit store: ld r9,264(r10) rldicl r9,r9,50,1 rotldi r9,r9,14 std r9,264(r10) ... ld r9,264(r10) rldicl r9,r9,40,1 rotldi r9,r9,24 std r9,264(r10) Fix this by using a temporary. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-29 20:03:50 +08:00
msr &= ~MSR_VSX;
powerpc: Add the ability to save Altivec without giving it up This patch adds the ability to be able to save the VEC registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch builds on a previous optimisation for the FPU registers in the thread copy path to avoid a possibly pointless reload of VEC state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:50 +08:00
#endif
powerpc: Avoid load hit store in __giveup_fpu() and __giveup_altivec() In both __giveup_fpu() and __giveup_altivec() we make two modifications to tsk->thread.regs->msr. gcc decides to do a read/modify/write of each change, so we end up with a load hit store: ld r9,264(r10) rldicl r9,r9,50,1 rotldi r9,r9,14 std r9,264(r10) ... ld r9,264(r10) rldicl r9,r9,40,1 rotldi r9,r9,24 std r9,264(r10) Fix this by using a temporary. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-29 20:03:50 +08:00
tsk->thread.regs->msr = msr;
powerpc: Add the ability to save Altivec without giving it up This patch adds the ability to be able to save the VEC registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch builds on a previous optimisation for the FPU registers in the thread copy path to avoid a possibly pointless reload of VEC state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:50 +08:00
}
powerpc: Move part of giveup_fpu,altivec,spe into c Move the MSR modification into new c functions. Removing it from the low level functions will allow us to avoid costly MSR writes by batching them up. Move the check_if_tm_restore_required() check into these new functions. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:01 +08:00
void giveup_altivec(struct task_struct *tsk)
{
check_if_tm_restore_required(tsk);
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
msr_check_and_set(MSR_VEC);
powerpc: Move part of giveup_fpu,altivec,spe into c Move the MSR modification into new c functions. Removing it from the low level functions will allow us to avoid costly MSR writes by batching them up. Move the check_if_tm_restore_required() check into these new functions. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:01 +08:00
__giveup_altivec(tsk);
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
msr_check_and_clear(MSR_VEC);
powerpc: Move part of giveup_fpu,altivec,spe into c Move the MSR modification into new c functions. Removing it from the low level functions will allow us to avoid costly MSR writes by batching them up. Move the check_if_tm_restore_required() check into these new functions. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:01 +08:00
}
EXPORT_SYMBOL(giveup_altivec);
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
void enable_kernel_altivec(void)
{
powerpc: Never giveup a reclaimed thread when enabling kernel {fp, altivec, vsx} After a thread is reclaimed from its active or suspended transactional state the checkpointed state exists on CPU, this state (along with the live/transactional state) has been saved in its entirety by the reclaiming process. There exists a sequence of events that would cause the kernel to call one of enable_kernel_fp(), enable_kernel_altivec() or enable_kernel_vsx() after a thread has been reclaimed. These functions save away any user state on the CPU so that the kernel can use the registers. Not only is this saving away unnecessary at this point, it is actually incorrect. It causes a save of the checkpointed state to the live structures within the thread struct thus destroying the true live state for that thread. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:11 +08:00
unsigned long cpumsr;
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
WARN_ON(preemptible());
powerpc: Never giveup a reclaimed thread when enabling kernel {fp, altivec, vsx} After a thread is reclaimed from its active or suspended transactional state the checkpointed state exists on CPU, this state (along with the live/transactional state) has been saved in its entirety by the reclaiming process. There exists a sequence of events that would cause the kernel to call one of enable_kernel_fp(), enable_kernel_altivec() or enable_kernel_vsx() after a thread has been reclaimed. These functions save away any user state on the CPU so that the kernel can use the registers. Not only is this saving away unnecessary at this point, it is actually incorrect. It causes a save of the checkpointed state to the live structures within the thread struct thus destroying the true live state for that thread. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:11 +08:00
cpumsr = msr_check_and_set(MSR_VEC);
powerpc: Create mtmsrd_isync() mtmsrd_isync() will do an mtmsrd followed by an isync on older processors. On newer processors we avoid the isync via a feature fixup. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:43:59 +08:00
powerpc: Call check_if_tm_restore_required() in enable_kernel_*() Commit a0e72cf12b1a ("powerpc: Create msr_check_and_{set,clear}()") removed a call to check_if_tm_restore_required() in the enable_kernel_*() functions. Add them back in. Fixes: a0e72cf12b1a ("powerpc: Create msr_check_and_{set,clear}()") Reported-by: Rashmica Gupta <rashmicy@gmail.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-10 17:04:05 +08:00
if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) {
check_if_tm_restore_required(current);
powerpc: Never giveup a reclaimed thread when enabling kernel {fp, altivec, vsx} After a thread is reclaimed from its active or suspended transactional state the checkpointed state exists on CPU, this state (along with the live/transactional state) has been saved in its entirety by the reclaiming process. There exists a sequence of events that would cause the kernel to call one of enable_kernel_fp(), enable_kernel_altivec() or enable_kernel_vsx() after a thread has been reclaimed. These functions save away any user state on the CPU so that the kernel can use the registers. Not only is this saving away unnecessary at this point, it is actually incorrect. It causes a save of the checkpointed state to the live structures within the thread struct thus destroying the true live state for that thread. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:11 +08:00
/*
* If a thread has already been reclaimed then the
* checkpointed registers are on the CPU but have definitely
* been saved by the reclaim code. Don't need to and *cannot*
* giveup as this would save to the 'live' structure not the
* checkpointed structure.
*/
if(!msr_tm_active(cpumsr) && msr_tm_active(current->thread.regs->msr))
return;
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
__giveup_altivec(current);
powerpc: Call check_if_tm_restore_required() in enable_kernel_*() Commit a0e72cf12b1a ("powerpc: Create msr_check_and_{set,clear}()") removed a call to check_if_tm_restore_required() in the enable_kernel_*() functions. Add them back in. Fixes: a0e72cf12b1a ("powerpc: Create msr_check_and_{set,clear}()") Reported-by: Rashmica Gupta <rashmicy@gmail.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-10 17:04:05 +08:00
}
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
}
EXPORT_SYMBOL(enable_kernel_altivec);
/*
* Make sure the VMX/Altivec register state in the
* the thread_struct is up to date for task tsk.
*/
void flush_altivec_to_thread(struct task_struct *tsk)
{
if (tsk->thread.regs) {
preempt_disable();
if (tsk->thread.regs->msr & MSR_VEC) {
BUG_ON(tsk != current);
powerpc: Simplify TM restore checks Instead of having multiple giveup_*_maybe_transactional() functions, separate out the TM check into a new function called check_if_tm_restore_required(). This will make it easier to optimise the giveup_*() functions in a subsequent patch. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:43:58 +08:00
giveup_altivec(tsk);
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
}
preempt_enable();
}
}
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
EXPORT_SYMBOL_GPL(flush_altivec_to_thread);
powerpc: Restore FPU/VEC/VSX if previously used Currently the FPU, VEC and VSX facilities are lazily loaded. This is not a problem unless a process is using these facilities. Modern versions of GCC are very good at automatically vectorising code, new and modernised workloads make use of floating point and vector facilities, even the kernel makes use of vectorised memcpy. All this combined greatly increases the cost of a syscall since the kernel uses the facilities sometimes even in syscall fast-path making it increasingly common for a thread to take an *_unavailable exception soon after a syscall, not to mention potentially taking all three. The obvious overcompensation to this problem is to simply always load all the facilities on every exit to userspace. Loading up all FPU, VEC and VSX registers every time can be expensive and if a workload does avoid using them, it should not be forced to incur this penalty. An 8bit counter is used to detect if the registers have been used in the past and the registers are always loaded until the value wraps to back to zero. Several versions of the assembly in entry_64.S were tested: 1. Always calling C. 2. Performing a common case check and then calling C. 3. A complex check in asm. After some benchmarking it was determined that avoiding C in the common case is a performance benefit (option 2). The full check in asm (option 3) greatly complicated that codepath for a negligible performance gain and the trade-off was deemed not worth it. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> [mpe: Move load_vec in the struct to fill an existing hole, reword change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> fixup
2016-02-29 14:53:47 +08:00
static int restore_altivec(struct task_struct *tsk)
{
powerpc: Always restore FPU/VEC/VSX if hardware transactional memory in use Comment from arch/powerpc/kernel/process.c:967: If userspace is inside a transaction (whether active or suspended) and FP/VMX/VSX instructions have ever been enabled inside that transaction, then we have to keep them enabled and keep the FP/VMX/VSX state loaded while ever the transaction continues. The reason is that if we didn't, and subsequently got a FP/VMX/VSX unavailable interrupt inside a transaction, we don't know whether it's the same transaction, and thus we don't know which of the checkpointed state and the ransactional state to use. restore_math() restore_fp() and restore_altivec() currently may not restore the registers. It doesn't appear that this is more serious than a performance penalty. If the math registers aren't restored the userspace thread will still be run with the facility disabled. Userspace will not be able to read invalid values. On the first access it will take an facility unavailable exception and the kernel will detected an active transaction, at which point it will abort the transaction. There is the possibility for a pathological case preventing any progress by transactions, however, transactions are never guaranteed to make progress. Fixes: 70fe3d9 ("powerpc: Restore FPU/VEC/VSX if previously used") Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:08 +08:00
if (cpu_has_feature(CPU_FTR_ALTIVEC) &&
(tsk->thread.load_vec || msr_tm_active(tsk->thread.regs->msr))) {
powerpc: Restore FPU/VEC/VSX if previously used Currently the FPU, VEC and VSX facilities are lazily loaded. This is not a problem unless a process is using these facilities. Modern versions of GCC are very good at automatically vectorising code, new and modernised workloads make use of floating point and vector facilities, even the kernel makes use of vectorised memcpy. All this combined greatly increases the cost of a syscall since the kernel uses the facilities sometimes even in syscall fast-path making it increasingly common for a thread to take an *_unavailable exception soon after a syscall, not to mention potentially taking all three. The obvious overcompensation to this problem is to simply always load all the facilities on every exit to userspace. Loading up all FPU, VEC and VSX registers every time can be expensive and if a workload does avoid using them, it should not be forced to incur this penalty. An 8bit counter is used to detect if the registers have been used in the past and the registers are always loaded until the value wraps to back to zero. Several versions of the assembly in entry_64.S were tested: 1. Always calling C. 2. Performing a common case check and then calling C. 3. A complex check in asm. After some benchmarking it was determined that avoiding C in the common case is a performance benefit (option 2). The full check in asm (option 3) greatly complicated that codepath for a negligible performance gain and the trade-off was deemed not worth it. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> [mpe: Move load_vec in the struct to fill an existing hole, reword change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> fixup
2016-02-29 14:53:47 +08:00
load_vr_state(&tsk->thread.vr_state);
tsk->thread.used_vr = 1;
tsk->thread.load_vec++;
return 1;
}
return 0;
}
#else
#define loadvec(thr) 0
static inline int restore_altivec(struct task_struct *tsk) { return 0; }
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
#endif /* CONFIG_ALTIVEC */
powerpc: Add VSX context save/restore, ptrace and signal support This patch extends the floating point save and restore code to use the VSX load/stores when VSX is available. This will make FP context save/restore marginally slower on FP only code, when VSX is available, as it has to load/store 128bits rather than just 64bits. Mixing FP, VMX and VSX code will get constant architected state. The signals interface is extended to enable access to VSR 0-31 doubleword 1 after discussions with tool chain maintainers. Backward compatibility is maintained. The ptrace interface is also extended to allow access to VSR 0-31 full registers. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-25 12:07:18 +08:00
#ifdef CONFIG_VSX
powerpc: Add the ability to save VSX without giving it up This patch adds the ability to be able to save the VSX registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch builds on a previous optimisation for the FPU and VEC registers in the thread copy path to avoid a possibly pointless reload of VSX state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:51 +08:00
static void __giveup_vsx(struct task_struct *tsk)
powerpc: Move part of giveup_vsx into c Move the MSR modification into c. Removing it from the assembly function will allow us to avoid costly MSR writes by batching them up. Check the FP and VMX bits before calling the relevant giveup_*() function. This makes giveup_vsx() and flush_vsx_to_thread() perform more like their sister functions, and allows us to use flush_vsx_to_thread() in the signal code. Move the check_if_tm_restore_required() check in. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:02 +08:00
{
if (tsk->thread.regs->msr & MSR_FP)
__giveup_fpu(tsk);
if (tsk->thread.regs->msr & MSR_VEC)
__giveup_altivec(tsk);
powerpc: Add the ability to save VSX without giving it up This patch adds the ability to be able to save the VSX registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch builds on a previous optimisation for the FPU and VEC registers in the thread copy path to avoid a possibly pointless reload of VSX state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:51 +08:00
tsk->thread.regs->msr &= ~MSR_VSX;
}
static void giveup_vsx(struct task_struct *tsk)
{
check_if_tm_restore_required(tsk);
msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
powerpc: Move part of giveup_vsx into c Move the MSR modification into c. Removing it from the assembly function will allow us to avoid costly MSR writes by batching them up. Check the FP and VMX bits before calling the relevant giveup_*() function. This makes giveup_vsx() and flush_vsx_to_thread() perform more like their sister functions, and allows us to use flush_vsx_to_thread() in the signal code. Move the check_if_tm_restore_required() check in. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:02 +08:00
__giveup_vsx(tsk);
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX);
powerpc: Move part of giveup_vsx into c Move the MSR modification into c. Removing it from the assembly function will allow us to avoid costly MSR writes by batching them up. Check the FP and VMX bits before calling the relevant giveup_*() function. This makes giveup_vsx() and flush_vsx_to_thread() perform more like their sister functions, and allows us to use flush_vsx_to_thread() in the signal code. Move the check_if_tm_restore_required() check in. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:02 +08:00
}
powerpc: Add the ability to save VSX without giving it up This patch adds the ability to be able to save the VSX registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch builds on a previous optimisation for the FPU and VEC registers in the thread copy path to avoid a possibly pointless reload of VSX state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:51 +08:00
static void save_vsx(struct task_struct *tsk)
{
if (tsk->thread.regs->msr & MSR_FP)
save_fpu(tsk);
if (tsk->thread.regs->msr & MSR_VEC)
save_altivec(tsk);
}
powerpc: Move part of giveup_vsx into c Move the MSR modification into c. Removing it from the assembly function will allow us to avoid costly MSR writes by batching them up. Check the FP and VMX bits before calling the relevant giveup_*() function. This makes giveup_vsx() and flush_vsx_to_thread() perform more like their sister functions, and allows us to use flush_vsx_to_thread() in the signal code. Move the check_if_tm_restore_required() check in. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:02 +08:00
powerpc: Add VSX context save/restore, ptrace and signal support This patch extends the floating point save and restore code to use the VSX load/stores when VSX is available. This will make FP context save/restore marginally slower on FP only code, when VSX is available, as it has to load/store 128bits rather than just 64bits. Mixing FP, VMX and VSX code will get constant architected state. The signals interface is extended to enable access to VSR 0-31 doubleword 1 after discussions with tool chain maintainers. Backward compatibility is maintained. The ptrace interface is also extended to allow access to VSR 0-31 full registers. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-25 12:07:18 +08:00
void enable_kernel_vsx(void)
{
powerpc: Never giveup a reclaimed thread when enabling kernel {fp, altivec, vsx} After a thread is reclaimed from its active or suspended transactional state the checkpointed state exists on CPU, this state (along with the live/transactional state) has been saved in its entirety by the reclaiming process. There exists a sequence of events that would cause the kernel to call one of enable_kernel_fp(), enable_kernel_altivec() or enable_kernel_vsx() after a thread has been reclaimed. These functions save away any user state on the CPU so that the kernel can use the registers. Not only is this saving away unnecessary at this point, it is actually incorrect. It causes a save of the checkpointed state to the live structures within the thread struct thus destroying the true live state for that thread. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:11 +08:00
unsigned long cpumsr;
powerpc: Add VSX context save/restore, ptrace and signal support This patch extends the floating point save and restore code to use the VSX load/stores when VSX is available. This will make FP context save/restore marginally slower on FP only code, when VSX is available, as it has to load/store 128bits rather than just 64bits. Mixing FP, VMX and VSX code will get constant architected state. The signals interface is extended to enable access to VSR 0-31 doubleword 1 after discussions with tool chain maintainers. Backward compatibility is maintained. The ptrace interface is also extended to allow access to VSR 0-31 full registers. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-25 12:07:18 +08:00
WARN_ON(preemptible());
powerpc: Never giveup a reclaimed thread when enabling kernel {fp, altivec, vsx} After a thread is reclaimed from its active or suspended transactional state the checkpointed state exists on CPU, this state (along with the live/transactional state) has been saved in its entirety by the reclaiming process. There exists a sequence of events that would cause the kernel to call one of enable_kernel_fp(), enable_kernel_altivec() or enable_kernel_vsx() after a thread has been reclaimed. These functions save away any user state on the CPU so that the kernel can use the registers. Not only is this saving away unnecessary at this point, it is actually incorrect. It causes a save of the checkpointed state to the live structures within the thread struct thus destroying the true live state for that thread. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:11 +08:00
cpumsr = msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
powerpc: Create mtmsrd_isync() mtmsrd_isync() will do an mtmsrd followed by an isync on older processors. On newer processors we avoid the isync via a feature fixup. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:43:59 +08:00
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
if (current->thread.regs && (current->thread.regs->msr & MSR_VSX)) {
powerpc: Call check_if_tm_restore_required() in enable_kernel_*() Commit a0e72cf12b1a ("powerpc: Create msr_check_and_{set,clear}()") removed a call to check_if_tm_restore_required() in the enable_kernel_*() functions. Add them back in. Fixes: a0e72cf12b1a ("powerpc: Create msr_check_and_{set,clear}()") Reported-by: Rashmica Gupta <rashmicy@gmail.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-10 17:04:05 +08:00
check_if_tm_restore_required(current);
powerpc: Never giveup a reclaimed thread when enabling kernel {fp, altivec, vsx} After a thread is reclaimed from its active or suspended transactional state the checkpointed state exists on CPU, this state (along with the live/transactional state) has been saved in its entirety by the reclaiming process. There exists a sequence of events that would cause the kernel to call one of enable_kernel_fp(), enable_kernel_altivec() or enable_kernel_vsx() after a thread has been reclaimed. These functions save away any user state on the CPU so that the kernel can use the registers. Not only is this saving away unnecessary at this point, it is actually incorrect. It causes a save of the checkpointed state to the live structures within the thread struct thus destroying the true live state for that thread. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:11 +08:00
/*
* If a thread has already been reclaimed then the
* checkpointed registers are on the CPU but have definitely
* been saved by the reclaim code. Don't need to and *cannot*
* giveup as this would save to the 'live' structure not the
* checkpointed structure.
*/
if(!msr_tm_active(cpumsr) && msr_tm_active(current->thread.regs->msr))
return;
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
if (current->thread.regs->msr & MSR_FP)
__giveup_fpu(current);
if (current->thread.regs->msr & MSR_VEC)
__giveup_altivec(current);
__giveup_vsx(current);
powerpc: Create mtmsrd_isync() mtmsrd_isync() will do an mtmsrd followed by an isync on older processors. On newer processors we avoid the isync via a feature fixup. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:43:59 +08:00
}
powerpc: Add VSX context save/restore, ptrace and signal support This patch extends the floating point save and restore code to use the VSX load/stores when VSX is available. This will make FP context save/restore marginally slower on FP only code, when VSX is available, as it has to load/store 128bits rather than just 64bits. Mixing FP, VMX and VSX code will get constant architected state. The signals interface is extended to enable access to VSR 0-31 doubleword 1 after discussions with tool chain maintainers. Backward compatibility is maintained. The ptrace interface is also extended to allow access to VSR 0-31 full registers. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-25 12:07:18 +08:00
}
EXPORT_SYMBOL(enable_kernel_vsx);
void flush_vsx_to_thread(struct task_struct *tsk)
{
if (tsk->thread.regs) {
preempt_disable();
if (tsk->thread.regs->msr & MSR_VSX) {
BUG_ON(tsk != current);
giveup_vsx(tsk);
}
preempt_enable();
}
}
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
EXPORT_SYMBOL_GPL(flush_vsx_to_thread);
powerpc: Restore FPU/VEC/VSX if previously used Currently the FPU, VEC and VSX facilities are lazily loaded. This is not a problem unless a process is using these facilities. Modern versions of GCC are very good at automatically vectorising code, new and modernised workloads make use of floating point and vector facilities, even the kernel makes use of vectorised memcpy. All this combined greatly increases the cost of a syscall since the kernel uses the facilities sometimes even in syscall fast-path making it increasingly common for a thread to take an *_unavailable exception soon after a syscall, not to mention potentially taking all three. The obvious overcompensation to this problem is to simply always load all the facilities on every exit to userspace. Loading up all FPU, VEC and VSX registers every time can be expensive and if a workload does avoid using them, it should not be forced to incur this penalty. An 8bit counter is used to detect if the registers have been used in the past and the registers are always loaded until the value wraps to back to zero. Several versions of the assembly in entry_64.S were tested: 1. Always calling C. 2. Performing a common case check and then calling C. 3. A complex check in asm. After some benchmarking it was determined that avoiding C in the common case is a performance benefit (option 2). The full check in asm (option 3) greatly complicated that codepath for a negligible performance gain and the trade-off was deemed not worth it. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> [mpe: Move load_vec in the struct to fill an existing hole, reword change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> fixup
2016-02-29 14:53:47 +08:00
static int restore_vsx(struct task_struct *tsk)
{
if (cpu_has_feature(CPU_FTR_VSX)) {
tsk->thread.used_vsr = 1;
return 1;
}
return 0;
}
#else
static inline int restore_vsx(struct task_struct *tsk) { return 0; }
powerpc: Add the ability to save VSX without giving it up This patch adds the ability to be able to save the VSX registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch builds on a previous optimisation for the FPU and VEC registers in the thread copy path to avoid a possibly pointless reload of VSX state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:51 +08:00
static inline void save_vsx(struct task_struct *tsk) { }
powerpc: Add VSX context save/restore, ptrace and signal support This patch extends the floating point save and restore code to use the VSX load/stores when VSX is available. This will make FP context save/restore marginally slower on FP only code, when VSX is available, as it has to load/store 128bits rather than just 64bits. Mixing FP, VMX and VSX code will get constant architected state. The signals interface is extended to enable access to VSR 0-31 doubleword 1 after discussions with tool chain maintainers. Backward compatibility is maintained. The ptrace interface is also extended to allow access to VSR 0-31 full registers. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-25 12:07:18 +08:00
#endif /* CONFIG_VSX */
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
#ifdef CONFIG_SPE
powerpc: Move part of giveup_fpu,altivec,spe into c Move the MSR modification into new c functions. Removing it from the low level functions will allow us to avoid costly MSR writes by batching them up. Move the check_if_tm_restore_required() check into these new functions. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:01 +08:00
void giveup_spe(struct task_struct *tsk)
{
check_if_tm_restore_required(tsk);
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
msr_check_and_set(MSR_SPE);
powerpc: Move part of giveup_fpu,altivec,spe into c Move the MSR modification into new c functions. Removing it from the low level functions will allow us to avoid costly MSR writes by batching them up. Move the check_if_tm_restore_required() check into these new functions. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:01 +08:00
__giveup_spe(tsk);
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
msr_check_and_clear(MSR_SPE);
powerpc: Move part of giveup_fpu,altivec,spe into c Move the MSR modification into new c functions. Removing it from the low level functions will allow us to avoid costly MSR writes by batching them up. Move the check_if_tm_restore_required() check into these new functions. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:01 +08:00
}
EXPORT_SYMBOL(giveup_spe);
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
void enable_kernel_spe(void)
{
WARN_ON(preemptible());
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
msr_check_and_set(MSR_SPE);
powerpc: Create mtmsrd_isync() mtmsrd_isync() will do an mtmsrd followed by an isync on older processors. On newer processors we avoid the isync via a feature fixup. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:43:59 +08:00
powerpc: Call check_if_tm_restore_required() in enable_kernel_*() Commit a0e72cf12b1a ("powerpc: Create msr_check_and_{set,clear}()") removed a call to check_if_tm_restore_required() in the enable_kernel_*() functions. Add them back in. Fixes: a0e72cf12b1a ("powerpc: Create msr_check_and_{set,clear}()") Reported-by: Rashmica Gupta <rashmicy@gmail.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-10 17:04:05 +08:00
if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) {
check_if_tm_restore_required(current);
powerpc: Create msr_check_and_{set,clear}() Create helper functions to set and clear MSR bits after first checking if they are already set. Grouping them will make it easy to avoid the MSR writes in a subsequent optimisation. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:04 +08:00
__giveup_spe(current);
powerpc: Call check_if_tm_restore_required() in enable_kernel_*() Commit a0e72cf12b1a ("powerpc: Create msr_check_and_{set,clear}()") removed a call to check_if_tm_restore_required() in the enable_kernel_*() functions. Add them back in. Fixes: a0e72cf12b1a ("powerpc: Create msr_check_and_{set,clear}()") Reported-by: Rashmica Gupta <rashmicy@gmail.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-10 17:04:05 +08:00
}
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
}
EXPORT_SYMBOL(enable_kernel_spe);
void flush_spe_to_thread(struct task_struct *tsk)
{
if (tsk->thread.regs) {
preempt_disable();
if (tsk->thread.regs->msr & MSR_SPE) {
BUG_ON(tsk != current);
powerpc/e500: Save SPEFCSR in flush_spe_to_thread() giveup_spe() saves the SPE state which is protected by MSR[SPE]. However, modifying SPEFSCR does not trap when MSR[SPE]=0. And since SPEFSCR is already saved/restored in _switch(), not all the callers want to save SPEFSCR again. Thus, saving SPEFSCR should not belong to giveup_spe(). This patch moves SPEFSCR saving to flush_spe_to_thread(), and cleans up the caller that needs to save SPEFSCR accordingly. Signed-off-by: Liu Yu <yu.liu@freescale.com> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-15 07:34:25 +08:00
tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
[POWERPC] Flush registers to proper task context When we flush register state for FP, Altivec, or SPE in flush_*_to_thread we need to respect the task_struct that the caller has passed to us. Most cases we are called with current, however sometimes (ptrace) we may be passed a different task_struct. This showed up when using gdbserver debugging a simple program that used floating point. When gdb tried to show the FP regs they all showed up as 0, because the child's FP registers were never properly flushed to memory. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-08-29 10:15:53 +08:00
giveup_spe(tsk);
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
}
preempt_enable();
}
}
#endif /* CONFIG_SPE */
powerpc: create giveup_all() Create a single function that gives everything up (FP, VMX, VSX, SPE). Doing this all at once means we only do one MSR write. A context switch microbenchmark using yield(): http://ozlabs.org/~anton/junkcode/context_switch2.c ./context_switch2 --test=yield --fp --altivec --vector 0 0 shows an improvement of 3% on POWER8. Signed-off-by: Anton Blanchard <anton@samba.org> [mpe: giveup_all() needs to be EXPORT_SYMBOL'ed] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:08 +08:00
static unsigned long msr_all_available;
static int __init init_msr_all_available(void)
{
#ifdef CONFIG_PPC_FPU
msr_all_available |= MSR_FP;
#endif
#ifdef CONFIG_ALTIVEC
if (cpu_has_feature(CPU_FTR_ALTIVEC))
msr_all_available |= MSR_VEC;
#endif
#ifdef CONFIG_VSX
if (cpu_has_feature(CPU_FTR_VSX))
msr_all_available |= MSR_VSX;
#endif
#ifdef CONFIG_SPE
if (cpu_has_feature(CPU_FTR_SPE))
msr_all_available |= MSR_SPE;
#endif
return 0;
}
early_initcall(init_msr_all_available);
void giveup_all(struct task_struct *tsk)
{
unsigned long usermsr;
if (!tsk->thread.regs)
return;
usermsr = tsk->thread.regs->msr;
if ((usermsr & msr_all_available) == 0)
return;
msr_check_and_set(msr_all_available);
powerpc: Add check_if_tm_restore_required() to giveup_all() giveup_all() causes FPU/VMX/VSX facilities to be disabled in a threads MSR. If the thread performing the giveup was transactional, the kernel must record which facilities were in use before the giveup as the thread must have these facilities re-enabled on return to userspace. >From process.c: /* * This is called if we are on the way out to userspace and the * TIF_RESTORE_TM flag is set. It checks if we need to reload * FP and/or vector state and does so if necessary. * If userspace is inside a transaction (whether active or * suspended) and FP/VMX/VSX instructions have ever been enabled * inside that transaction, then we have to keep them enabled * and keep the FP/VMX/VSX state loaded while ever the transaction * continues. The reason is that if we didn't, and subsequently * got a FP/VMX/VSX unavailable interrupt inside a transaction, * we don't know whether it's the same transaction, and thus we * don't know which of the checkpointed state and the transactional * state to use. */ Calling check_if_tm_restore_required() will set TIF_RESTORE_TM and save the MSR if needed. Fixes: c208505 ("powerpc: create giveup_all()") Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:09 +08:00
check_if_tm_restore_required(tsk);
powerpc: create giveup_all() Create a single function that gives everything up (FP, VMX, VSX, SPE). Doing this all at once means we only do one MSR write. A context switch microbenchmark using yield(): http://ozlabs.org/~anton/junkcode/context_switch2.c ./context_switch2 --test=yield --fp --altivec --vector 0 0 shows an improvement of 3% on POWER8. Signed-off-by: Anton Blanchard <anton@samba.org> [mpe: giveup_all() needs to be EXPORT_SYMBOL'ed] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:08 +08:00
#ifdef CONFIG_PPC_FPU
if (usermsr & MSR_FP)
__giveup_fpu(tsk);
#endif
#ifdef CONFIG_ALTIVEC
if (usermsr & MSR_VEC)
__giveup_altivec(tsk);
#endif
#ifdef CONFIG_VSX
if (usermsr & MSR_VSX)
__giveup_vsx(tsk);
#endif
#ifdef CONFIG_SPE
if (usermsr & MSR_SPE)
__giveup_spe(tsk);
#endif
msr_check_and_clear(msr_all_available);
}
EXPORT_SYMBOL(giveup_all);
powerpc: Restore FPU/VEC/VSX if previously used Currently the FPU, VEC and VSX facilities are lazily loaded. This is not a problem unless a process is using these facilities. Modern versions of GCC are very good at automatically vectorising code, new and modernised workloads make use of floating point and vector facilities, even the kernel makes use of vectorised memcpy. All this combined greatly increases the cost of a syscall since the kernel uses the facilities sometimes even in syscall fast-path making it increasingly common for a thread to take an *_unavailable exception soon after a syscall, not to mention potentially taking all three. The obvious overcompensation to this problem is to simply always load all the facilities on every exit to userspace. Loading up all FPU, VEC and VSX registers every time can be expensive and if a workload does avoid using them, it should not be forced to incur this penalty. An 8bit counter is used to detect if the registers have been used in the past and the registers are always loaded until the value wraps to back to zero. Several versions of the assembly in entry_64.S were tested: 1. Always calling C. 2. Performing a common case check and then calling C. 3. A complex check in asm. After some benchmarking it was determined that avoiding C in the common case is a performance benefit (option 2). The full check in asm (option 3) greatly complicated that codepath for a negligible performance gain and the trade-off was deemed not worth it. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> [mpe: Move load_vec in the struct to fill an existing hole, reword change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> fixup
2016-02-29 14:53:47 +08:00
void restore_math(struct pt_regs *regs)
{
unsigned long msr;
powerpc: Always restore FPU/VEC/VSX if hardware transactional memory in use Comment from arch/powerpc/kernel/process.c:967: If userspace is inside a transaction (whether active or suspended) and FP/VMX/VSX instructions have ever been enabled inside that transaction, then we have to keep them enabled and keep the FP/VMX/VSX state loaded while ever the transaction continues. The reason is that if we didn't, and subsequently got a FP/VMX/VSX unavailable interrupt inside a transaction, we don't know whether it's the same transaction, and thus we don't know which of the checkpointed state and the ransactional state to use. restore_math() restore_fp() and restore_altivec() currently may not restore the registers. It doesn't appear that this is more serious than a performance penalty. If the math registers aren't restored the userspace thread will still be run with the facility disabled. Userspace will not be able to read invalid values. On the first access it will take an facility unavailable exception and the kernel will detected an active transaction, at which point it will abort the transaction. There is the possibility for a pathological case preventing any progress by transactions, however, transactions are never guaranteed to make progress. Fixes: 70fe3d9 ("powerpc: Restore FPU/VEC/VSX if previously used") Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:08 +08:00
if (!msr_tm_active(regs->msr) &&
!current->thread.load_fp && !loadvec(current->thread))
powerpc: Restore FPU/VEC/VSX if previously used Currently the FPU, VEC and VSX facilities are lazily loaded. This is not a problem unless a process is using these facilities. Modern versions of GCC are very good at automatically vectorising code, new and modernised workloads make use of floating point and vector facilities, even the kernel makes use of vectorised memcpy. All this combined greatly increases the cost of a syscall since the kernel uses the facilities sometimes even in syscall fast-path making it increasingly common for a thread to take an *_unavailable exception soon after a syscall, not to mention potentially taking all three. The obvious overcompensation to this problem is to simply always load all the facilities on every exit to userspace. Loading up all FPU, VEC and VSX registers every time can be expensive and if a workload does avoid using them, it should not be forced to incur this penalty. An 8bit counter is used to detect if the registers have been used in the past and the registers are always loaded until the value wraps to back to zero. Several versions of the assembly in entry_64.S were tested: 1. Always calling C. 2. Performing a common case check and then calling C. 3. A complex check in asm. After some benchmarking it was determined that avoiding C in the common case is a performance benefit (option 2). The full check in asm (option 3) greatly complicated that codepath for a negligible performance gain and the trade-off was deemed not worth it. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> [mpe: Move load_vec in the struct to fill an existing hole, reword change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> fixup
2016-02-29 14:53:47 +08:00
return;
msr = regs->msr;
msr_check_and_set(msr_all_available);
/*
* Only reload if the bit is not set in the user MSR, the bit BEING set
* indicates that the registers are hot
*/
if ((!(msr & MSR_FP)) && restore_fp(current))
msr |= MSR_FP | current->thread.fpexc_mode;
if ((!(msr & MSR_VEC)) && restore_altivec(current))
msr |= MSR_VEC;
if ((msr & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC) &&
restore_vsx(current)) {
msr |= MSR_VSX;
}
msr_check_and_clear(msr_all_available);
regs->msr = msr;
}
powerpc: Prepare for splitting giveup_{fpu, altivec, vsx} in two This prepares for the decoupling of saving {fpu,altivec,vsx} registers and marking {fpu,altivec,vsx} as being unused by a thread. Currently giveup_{fpu,altivec,vsx}() does both however optimisations to task switching can be made if these two operations are decoupled. save_all() will permit the saving of registers to thread structs and leave threads MSR with bits enabled. This patch introduces no functional change. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:48 +08:00
void save_all(struct task_struct *tsk)
{
unsigned long usermsr;
if (!tsk->thread.regs)
return;
usermsr = tsk->thread.regs->msr;
if ((usermsr & msr_all_available) == 0)
return;
msr_check_and_set(msr_all_available);
powerpc: Add the ability to save VSX without giving it up This patch adds the ability to be able to save the VSX registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch builds on a previous optimisation for the FPU and VEC registers in the thread copy path to avoid a possibly pointless reload of VSX state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:51 +08:00
/*
* Saving the way the register space is in hardware, save_vsx boils
* down to a save_fpu() and save_altivec()
*/
if (usermsr & MSR_VSX) {
save_vsx(tsk);
} else {
if (usermsr & MSR_FP)
save_fpu(tsk);
if (usermsr & MSR_VEC)
save_altivec(tsk);
}
powerpc: Prepare for splitting giveup_{fpu, altivec, vsx} in two This prepares for the decoupling of saving {fpu,altivec,vsx} registers and marking {fpu,altivec,vsx} as being unused by a thread. Currently giveup_{fpu,altivec,vsx}() does both however optimisations to task switching can be made if these two operations are decoupled. save_all() will permit the saving of registers to thread structs and leave threads MSR with bits enabled. This patch introduces no functional change. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:48 +08:00
if (usermsr & MSR_SPE)
__giveup_spe(tsk);
msr_check_and_clear(msr_all_available);
}
powerpc: create flush_all_to_thread() Create a single function that flushes everything (FP, VMX, VSX, SPE). Doing this all at once means we only do one MSR write. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:09 +08:00
void flush_all_to_thread(struct task_struct *tsk)
{
if (tsk->thread.regs) {
preempt_disable();
BUG_ON(tsk != current);
powerpc: Prepare for splitting giveup_{fpu, altivec, vsx} in two This prepares for the decoupling of saving {fpu,altivec,vsx} registers and marking {fpu,altivec,vsx} as being unused by a thread. Currently giveup_{fpu,altivec,vsx}() does both however optimisations to task switching can be made if these two operations are decoupled. save_all() will permit the saving of registers to thread structs and leave threads MSR with bits enabled. This patch introduces no functional change. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:48 +08:00
save_all(tsk);
powerpc: create flush_all_to_thread() Create a single function that flushes everything (FP, VMX, VSX, SPE). Doing this all at once means we only do one MSR write. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:09 +08:00
#ifdef CONFIG_SPE
if (tsk->thread.regs->msr & MSR_SPE)
tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
#endif
preempt_enable();
}
}
EXPORT_SYMBOL(flush_all_to_thread);
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
void do_send_trap(struct pt_regs *regs, unsigned long address,
unsigned long error_code, int signal_code, int breakpt)
{
siginfo_t info;
powerpc: Add trap_nr to thread_struct Add thread_struct.trap_nr and use it to store the last exception the thread experienced. In this patch, we populate the field at various places where we force_sig_info() to the process. This is also used in uprobes to determine if the probed instruction caused an exception. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-08-24 05:27:09 +08:00
current->thread.trap_nr = signal_code;
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
11, SIGSEGV) == NOTIFY_STOP)
return;
/* Deliver the signal to userspace */
info.si_signo = SIGTRAP;
info.si_errno = breakpt; /* breakpoint or watchpoint id */
info.si_code = signal_code;
info.si_addr = (void __user *)address;
force_sig_info(SIGTRAP, &info, current);
}
#else /* !CONFIG_PPC_ADV_DEBUG_REGS */
powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:44 +08:00
void do_break (struct pt_regs *regs, unsigned long address,
powerpc: BookE hardware watchpoint support This patch implements support for HW based watchpoint via the DBSR_DAC (Data Address Compare) facility of the BookE processors. It does so by interfacing with the existing DABR breakpoint code and adding the necessary bits and pieces for the new bits to be properly set or cleared Signed-off-by: Luis Machado <luisgpm@br.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-24 00:10:41 +08:00
unsigned long error_code)
{
siginfo_t info;
powerpc: Add trap_nr to thread_struct Add thread_struct.trap_nr and use it to store the last exception the thread experienced. In this patch, we populate the field at various places where we force_sig_info() to the process. This is also used in uprobes to determine if the probed instruction caused an exception. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-08-24 05:27:09 +08:00
current->thread.trap_nr = TRAP_HWBKPT;
powerpc: BookE hardware watchpoint support This patch implements support for HW based watchpoint via the DBSR_DAC (Data Address Compare) facility of the BookE processors. It does so by interfacing with the existing DABR breakpoint code and adding the necessary bits and pieces for the new bits to be properly set or cleared Signed-off-by: Luis Machado <luisgpm@br.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-24 00:10:41 +08:00
if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
11, SIGSEGV) == NOTIFY_STOP)
return;
powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:44 +08:00
if (debugger_break_match(regs))
powerpc: BookE hardware watchpoint support This patch implements support for HW based watchpoint via the DBSR_DAC (Data Address Compare) facility of the BookE processors. It does so by interfacing with the existing DABR breakpoint code and adding the necessary bits and pieces for the new bits to be properly set or cleared Signed-off-by: Luis Machado <luisgpm@br.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-24 00:10:41 +08:00
return;
powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:44 +08:00
/* Clear the breakpoint */
hw_breakpoint_disable();
powerpc: BookE hardware watchpoint support This patch implements support for HW based watchpoint via the DBSR_DAC (Data Address Compare) facility of the BookE processors. It does so by interfacing with the existing DABR breakpoint code and adding the necessary bits and pieces for the new bits to be properly set or cleared Signed-off-by: Luis Machado <luisgpm@br.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-24 00:10:41 +08:00
/* Deliver the signal to userspace */
info.si_signo = SIGTRAP;
info.si_errno = 0;
info.si_code = TRAP_HWBKPT;
info.si_addr = (void __user *)address;
force_sig_info(SIGTRAP, &info, current);
}
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
powerpc: BookE hardware watchpoint support This patch implements support for HW based watchpoint via the DBSR_DAC (Data Address Compare) facility of the BookE processors. It does so by interfacing with the existing DABR breakpoint code and adding the necessary bits and pieces for the new bits to be properly set or cleared Signed-off-by: Luis Machado <luisgpm@br.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-24 00:10:41 +08:00
powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:44 +08:00
static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk);
[POWERPC] Fix missed hardware breakpoints across multiple threads There is a bug in the powerpc DABR (data access breakpoint) handling, which can result in us missing breakpoints if several threads are trying to break on the same address. The circumstances are that do_page_fault() calls do_dabr(), this clears the DABR (sets it to 0) and sets up the signal which will report to userspace that the DABR was hit. The do_signal() code will restore the DABR value on the way out to userspace. If we reschedule before calling do_signal(), __switch_to() will check the cached DABR value and compare it to the new thread's value, if they match we don't set the DABR in hardware. So if two threads have the same DABR value, and we schedule from one to the other after taking the interrupt for the first thread hitting the DABR, the second thread will run without the DABR set in hardware. The cleanest fix is to move the cache update into set_dabr(), that way we can't forget to do it. Reported-by: Jan Kratochvil <jan.kratochvil@redhat.com> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-03-28 16:11:48 +08:00
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
/*
* Set the debug registers back to their default "safe" values.
*/
static void set_debug_reg_defaults(struct thread_struct *thread)
{
powerpc: move debug registers in a structure This way we can use same data type struct with KVM and also help in using other debug related function. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Acked-by: Michael Neuling <mikey@neuling.org> [scottwood@freescale.com: removed obvious debug_reg comment] Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-07-04 14:15:46 +08:00
thread->debug.iac1 = thread->debug.iac2 = 0;
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#if CONFIG_PPC_ADV_DEBUG_IACS > 2
powerpc: move debug registers in a structure This way we can use same data type struct with KVM and also help in using other debug related function. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Acked-by: Michael Neuling <mikey@neuling.org> [scottwood@freescale.com: removed obvious debug_reg comment] Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-07-04 14:15:46 +08:00
thread->debug.iac3 = thread->debug.iac4 = 0;
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#endif
powerpc: move debug registers in a structure This way we can use same data type struct with KVM and also help in using other debug related function. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Acked-by: Michael Neuling <mikey@neuling.org> [scottwood@freescale.com: removed obvious debug_reg comment] Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-07-04 14:15:46 +08:00
thread->debug.dac1 = thread->debug.dac2 = 0;
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
powerpc: move debug registers in a structure This way we can use same data type struct with KVM and also help in using other debug related function. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Acked-by: Michael Neuling <mikey@neuling.org> [scottwood@freescale.com: removed obvious debug_reg comment] Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-07-04 14:15:46 +08:00
thread->debug.dvc1 = thread->debug.dvc2 = 0;
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#endif
powerpc: move debug registers in a structure This way we can use same data type struct with KVM and also help in using other debug related function. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Acked-by: Michael Neuling <mikey@neuling.org> [scottwood@freescale.com: removed obvious debug_reg comment] Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-07-04 14:15:46 +08:00
thread->debug.dbcr0 = 0;
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#ifdef CONFIG_BOOKE
/*
* Force User/Supervisor bits to b11 (user-only MSR[PR]=1)
*/
powerpc: move debug registers in a structure This way we can use same data type struct with KVM and also help in using other debug related function. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Acked-by: Michael Neuling <mikey@neuling.org> [scottwood@freescale.com: removed obvious debug_reg comment] Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-07-04 14:15:46 +08:00
thread->debug.dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US |
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
DBCR1_IAC3US | DBCR1_IAC4US;
/*
* Force Data Address Compare User/Supervisor bits to be User-only
* (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0.
*/
powerpc: move debug registers in a structure This way we can use same data type struct with KVM and also help in using other debug related function. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Acked-by: Michael Neuling <mikey@neuling.org> [scottwood@freescale.com: removed obvious debug_reg comment] Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-07-04 14:15:46 +08:00
thread->debug.dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US;
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#else
powerpc: move debug registers in a structure This way we can use same data type struct with KVM and also help in using other debug related function. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Acked-by: Michael Neuling <mikey@neuling.org> [scottwood@freescale.com: removed obvious debug_reg comment] Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-07-04 14:15:46 +08:00
thread->debug.dbcr1 = 0;
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#endif
}
powerpc/kvm/booke: Fix build break due to stack frame size warning Commit ce11e48b7fdd256ec68b932a89b397a790566031 ("KVM: PPC: E500: Add userspace debug stub support") added "struct thread_struct" to the stack of kvmppc_vcpu_run(). thread_struct is 1152 bytes on my build, compared to 48 bytes for the recently-introduced "struct debug_reg". Use the latter instead. This fixes the following error: cc1: warnings being treated as errors arch/powerpc/kvm/booke.c: In function 'kvmppc_vcpu_run': arch/powerpc/kvm/booke.c:760:1: error: the frame size of 1424 bytes is larger than 1024 bytes make[2]: *** [arch/powerpc/kvm/booke.o] Error 1 make[1]: *** [arch/powerpc/kvm] Error 2 make[1]: *** Waiting for unfinished jobs.... Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-11-23 05:52:29 +08:00
static void prime_debug_regs(struct debug_reg *debug)
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
{
powerpc/booke64: Fix kernel hangs at kernel_dbg_exc MSR_DE is not cleared on entry to the kernel, and we don't clear it explicitly outside of debug code. If we have MSR_DE set in prime_debug_regs(), and the new thread has events enabled in DBCR0 (e.g. ICMP is set in thread->dbsr0, even though it was cleared in the real DBCR0 when the thread got scheduled out), we'll end up taking a debug exception in the kernel when DBCR0 is loaded. DSRR0 will not point to an exception vector, and the kernel ends up hanging at kernel_dbg_exc. Fix this by always clearing MSR_DE when we load new debug state. Another observed source of kernel_dbg_exc hangs is with the branch taken event. If this event is active, but we take a non-debug trap (e.g. a TLB miss or an asynchronous interrupt) before the next branch. We end up taking a branch-taken debug exception on the initial branch instruction of the exception vector, but because the debug exception is DBSR_BT rather than DBSR_IC we branch to kernel_dbg_exc before even checking the DSRR0 address. Fix this by checking for DBSR_BT as well as DBSR_IC, which is what 32-bit does and what the comments suggest was intended in the 64-bit code as well. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-13 22:14:53 +08:00
/*
* We could have inherited MSR_DE from userspace, since
* it doesn't get cleared on exception entry. Make sure
* MSR_DE is clear before we enable any debug events.
*/
mtmsr(mfmsr() & ~MSR_DE);
powerpc/kvm/booke: Fix build break due to stack frame size warning Commit ce11e48b7fdd256ec68b932a89b397a790566031 ("KVM: PPC: E500: Add userspace debug stub support") added "struct thread_struct" to the stack of kvmppc_vcpu_run(). thread_struct is 1152 bytes on my build, compared to 48 bytes for the recently-introduced "struct debug_reg". Use the latter instead. This fixes the following error: cc1: warnings being treated as errors arch/powerpc/kvm/booke.c: In function 'kvmppc_vcpu_run': arch/powerpc/kvm/booke.c:760:1: error: the frame size of 1424 bytes is larger than 1024 bytes make[2]: *** [arch/powerpc/kvm/booke.o] Error 1 make[1]: *** [arch/powerpc/kvm] Error 2 make[1]: *** Waiting for unfinished jobs.... Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-11-23 05:52:29 +08:00
mtspr(SPRN_IAC1, debug->iac1);
mtspr(SPRN_IAC2, debug->iac2);
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#if CONFIG_PPC_ADV_DEBUG_IACS > 2
powerpc/kvm/booke: Fix build break due to stack frame size warning Commit ce11e48b7fdd256ec68b932a89b397a790566031 ("KVM: PPC: E500: Add userspace debug stub support") added "struct thread_struct" to the stack of kvmppc_vcpu_run(). thread_struct is 1152 bytes on my build, compared to 48 bytes for the recently-introduced "struct debug_reg". Use the latter instead. This fixes the following error: cc1: warnings being treated as errors arch/powerpc/kvm/booke.c: In function 'kvmppc_vcpu_run': arch/powerpc/kvm/booke.c:760:1: error: the frame size of 1424 bytes is larger than 1024 bytes make[2]: *** [arch/powerpc/kvm/booke.o] Error 1 make[1]: *** [arch/powerpc/kvm] Error 2 make[1]: *** Waiting for unfinished jobs.... Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-11-23 05:52:29 +08:00
mtspr(SPRN_IAC3, debug->iac3);
mtspr(SPRN_IAC4, debug->iac4);
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#endif
powerpc/kvm/booke: Fix build break due to stack frame size warning Commit ce11e48b7fdd256ec68b932a89b397a790566031 ("KVM: PPC: E500: Add userspace debug stub support") added "struct thread_struct" to the stack of kvmppc_vcpu_run(). thread_struct is 1152 bytes on my build, compared to 48 bytes for the recently-introduced "struct debug_reg". Use the latter instead. This fixes the following error: cc1: warnings being treated as errors arch/powerpc/kvm/booke.c: In function 'kvmppc_vcpu_run': arch/powerpc/kvm/booke.c:760:1: error: the frame size of 1424 bytes is larger than 1024 bytes make[2]: *** [arch/powerpc/kvm/booke.o] Error 1 make[1]: *** [arch/powerpc/kvm] Error 2 make[1]: *** Waiting for unfinished jobs.... Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-11-23 05:52:29 +08:00
mtspr(SPRN_DAC1, debug->dac1);
mtspr(SPRN_DAC2, debug->dac2);
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
powerpc/kvm/booke: Fix build break due to stack frame size warning Commit ce11e48b7fdd256ec68b932a89b397a790566031 ("KVM: PPC: E500: Add userspace debug stub support") added "struct thread_struct" to the stack of kvmppc_vcpu_run(). thread_struct is 1152 bytes on my build, compared to 48 bytes for the recently-introduced "struct debug_reg". Use the latter instead. This fixes the following error: cc1: warnings being treated as errors arch/powerpc/kvm/booke.c: In function 'kvmppc_vcpu_run': arch/powerpc/kvm/booke.c:760:1: error: the frame size of 1424 bytes is larger than 1024 bytes make[2]: *** [arch/powerpc/kvm/booke.o] Error 1 make[1]: *** [arch/powerpc/kvm] Error 2 make[1]: *** Waiting for unfinished jobs.... Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-11-23 05:52:29 +08:00
mtspr(SPRN_DVC1, debug->dvc1);
mtspr(SPRN_DVC2, debug->dvc2);
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#endif
powerpc/kvm/booke: Fix build break due to stack frame size warning Commit ce11e48b7fdd256ec68b932a89b397a790566031 ("KVM: PPC: E500: Add userspace debug stub support") added "struct thread_struct" to the stack of kvmppc_vcpu_run(). thread_struct is 1152 bytes on my build, compared to 48 bytes for the recently-introduced "struct debug_reg". Use the latter instead. This fixes the following error: cc1: warnings being treated as errors arch/powerpc/kvm/booke.c: In function 'kvmppc_vcpu_run': arch/powerpc/kvm/booke.c:760:1: error: the frame size of 1424 bytes is larger than 1024 bytes make[2]: *** [arch/powerpc/kvm/booke.o] Error 1 make[1]: *** [arch/powerpc/kvm] Error 2 make[1]: *** Waiting for unfinished jobs.... Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-11-23 05:52:29 +08:00
mtspr(SPRN_DBCR0, debug->dbcr0);
mtspr(SPRN_DBCR1, debug->dbcr1);
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#ifdef CONFIG_BOOKE
powerpc/kvm/booke: Fix build break due to stack frame size warning Commit ce11e48b7fdd256ec68b932a89b397a790566031 ("KVM: PPC: E500: Add userspace debug stub support") added "struct thread_struct" to the stack of kvmppc_vcpu_run(). thread_struct is 1152 bytes on my build, compared to 48 bytes for the recently-introduced "struct debug_reg". Use the latter instead. This fixes the following error: cc1: warnings being treated as errors arch/powerpc/kvm/booke.c: In function 'kvmppc_vcpu_run': arch/powerpc/kvm/booke.c:760:1: error: the frame size of 1424 bytes is larger than 1024 bytes make[2]: *** [arch/powerpc/kvm/booke.o] Error 1 make[1]: *** [arch/powerpc/kvm] Error 2 make[1]: *** Waiting for unfinished jobs.... Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-11-23 05:52:29 +08:00
mtspr(SPRN_DBCR2, debug->dbcr2);
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#endif
}
/*
* Unless neither the old or new thread are making use of the
* debug registers, set the debug registers from the values
* stored in the new thread.
*/
powerpc/kvm/booke: Fix build break due to stack frame size warning Commit ce11e48b7fdd256ec68b932a89b397a790566031 ("KVM: PPC: E500: Add userspace debug stub support") added "struct thread_struct" to the stack of kvmppc_vcpu_run(). thread_struct is 1152 bytes on my build, compared to 48 bytes for the recently-introduced "struct debug_reg". Use the latter instead. This fixes the following error: cc1: warnings being treated as errors arch/powerpc/kvm/booke.c: In function 'kvmppc_vcpu_run': arch/powerpc/kvm/booke.c:760:1: error: the frame size of 1424 bytes is larger than 1024 bytes make[2]: *** [arch/powerpc/kvm/booke.o] Error 1 make[1]: *** [arch/powerpc/kvm] Error 2 make[1]: *** Waiting for unfinished jobs.... Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-11-23 05:52:29 +08:00
void switch_booke_debug_regs(struct debug_reg *new_debug)
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
{
powerpc: move debug registers in a structure This way we can use same data type struct with KVM and also help in using other debug related function. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Acked-by: Michael Neuling <mikey@neuling.org> [scottwood@freescale.com: removed obvious debug_reg comment] Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-07-04 14:15:46 +08:00
if ((current->thread.debug.dbcr0 & DBCR0_IDM)
powerpc/kvm/booke: Fix build break due to stack frame size warning Commit ce11e48b7fdd256ec68b932a89b397a790566031 ("KVM: PPC: E500: Add userspace debug stub support") added "struct thread_struct" to the stack of kvmppc_vcpu_run(). thread_struct is 1152 bytes on my build, compared to 48 bytes for the recently-introduced "struct debug_reg". Use the latter instead. This fixes the following error: cc1: warnings being treated as errors arch/powerpc/kvm/booke.c: In function 'kvmppc_vcpu_run': arch/powerpc/kvm/booke.c:760:1: error: the frame size of 1424 bytes is larger than 1024 bytes make[2]: *** [arch/powerpc/kvm/booke.o] Error 1 make[1]: *** [arch/powerpc/kvm] Error 2 make[1]: *** Waiting for unfinished jobs.... Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-11-23 05:52:29 +08:00
|| (new_debug->dbcr0 & DBCR0_IDM))
prime_debug_regs(new_debug);
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
}
powerpc: export debug registers save function for KVM KVM need this function when switching from vcpu to user-space thread. My subsequent patch will use this function. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-07-04 14:57:44 +08:00
EXPORT_SYMBOL_GPL(switch_booke_debug_regs);
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#else /* !CONFIG_PPC_ADV_DEBUG_REGS */
powerpc: Fix call to flush_ptrace_hw_breakpoint() Fix the error in spelling the config option for hw-breakpoints and fix the build issue that follows. Signed-off by: K.Prasad <prasad@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-02-10 12:44:35 +08:00
#ifndef CONFIG_HAVE_HW_BREAKPOINT
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
static void set_debug_reg_defaults(struct thread_struct *thread)
{
powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:44 +08:00
thread->hw_brk.address = 0;
thread->hw_brk.type = 0;
powerpc: Rename set_break to avoid naming conflict With allmodconfig we are getting: drivers/tty/synclink_gt.c:160:12: error: conflicting types for 'set_break' arch/powerpc/include/asm/debug.h:49:5: note: previous declaration of 'set_break' was here drivers/tty/synclinkmp.c:526:12: error: conflicting types for 'set_break' arch/powerpc/include/asm/debug.h:49:5: note: previous declaration of 'set_break' was here This renames set_break to set_breakpoint to avoid this naming conflict Signed-off-by: Michael Neuling <mikey@neuling.org> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-10 22:25:34 +08:00
set_breakpoint(&thread->hw_brk);
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
}
powerpc: Fix call to flush_ptrace_hw_breakpoint() Fix the error in spelling the config option for hw-breakpoints and fix the build issue that follows. Signed-off by: K.Prasad <prasad@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-02-10 12:44:35 +08:00
#endif /* !CONFIG_HAVE_HW_BREAKPOINT */
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
powerpc/booke: Introduce new CONFIG options for advanced debug registers powerpc/booke: Introduce new CONFIG options for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Introduce new config options to simplify the ifdefs pertaining to the advanced debug registers for booke and 40x processors: CONFIG_PPC_ADV_DEBUG_REGS - boolean: true for dac-based processors CONFIG_PPC_ADV_DEBUG_IACS - number of IAC registers CONFIG_PPC_ADV_DEBUG_DACS - number of DAC registers CONFIG_PPC_ADV_DEBUG_DVCS - number of DVC registers CONFIG_PPC_ADV_DEBUG_DAC_RANGE - DAC ranges supported Beginning conservatively, since I only have the facilities to test 440 hardware. I believe all 40x and booke platforms support at least 2 IAC and 2 DAC registers. For 440, 4 IAC and 2 DVC registers are enabled, as well as the DAC ranges. Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Acked-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:50:57 +08:00
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:44 +08:00
static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
{
powerpc: BookE hardware watchpoint support This patch implements support for HW based watchpoint via the DBSR_DAC (Data Address Compare) facility of the BookE processors. It does so by interfacing with the existing DABR breakpoint code and adding the necessary bits and pieces for the new bits to be properly set or cleared Signed-off-by: Luis Machado <luisgpm@br.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-24 00:10:41 +08:00
mtspr(SPRN_DAC1, dabr);
powerpc/476: Add isync after loading mmu and debug spr's 476 requires an isync after loading MMU and debug related SPR's. Some of these are in performance-critical paths and may need to be optimized, but initially, we're playing it safe. Signed-off-by: Torez Smith <lnxtorez@linux.vnet.ibm.com> Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
2010-03-05 18:43:24 +08:00
#ifdef CONFIG_PPC_47x
isync();
#endif
powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:44 +08:00
return 0;
}
powerpc/booke: Don't set DABR on 64-bit BookE, use DAC1 instead Also remove a duplicate setting of it in the context switch path on BookE. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-09-08 22:16:58 +08:00
#elif defined(CONFIG_PPC_BOOK3S)
powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:44 +08:00
static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
{
powerpc/booke: Don't set DABR on 64-bit BookE, use DAC1 instead Also remove a duplicate setting of it in the context switch path on BookE. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-09-08 22:16:58 +08:00
mtspr(SPRN_DABR, dabr);
powerpc/hw_breakpoints: Add DABRX cpu feature to fix 32-bit regression When introducing support for DABRX in 4474ef0, we broke older 32-bit CPUs that don't have that register. Some CPUs have a DABR but not DABRX. Configuration are: - No 32bit CPUs have DABRX but some have DABR. - POWER4+ and below have the DABR but no DABRX. - 970 and POWER5 and above have DABR and DABRX. - POWER8 has DAWR, hence no DABRX. This introduces CPU_FTR_DABRX and sets it on appropriate CPUs. We use the top 64 bits for CPU FTR bits since only 64 bit CPUs have this. Processors that don't have the DABRX will still work as they will fall back to software filtering these breakpoints via perf_exclude_event(). Signed-off-by: Michael Neuling <mikey@neuling.org> Reported-by: "Gorelik, Jacob (335F)" <jacob.gorelik@jpl.nasa.gov> cc: stable@vger.kernel.org (v3.9 only) Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-17 04:27:31 +08:00
if (cpu_has_feature(CPU_FTR_DABRX))
mtspr(SPRN_DABRX, dabrx);
powerpc: Make set_dabr() a ppc_md function Move pSeries specific code in set_dabr() into a ppc_md function, this will allow us to keep plpar_wrappers.h private to platforms/pseries. Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
2005-11-03 12:30:49 +08:00
return 0;
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
}
powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:44 +08:00
#else
static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
{
return -EINVAL;
}
#endif
static inline int set_dabr(struct arch_hw_breakpoint *brk)
{
unsigned long dabr, dabrx;
dabr = brk->address | (brk->type & HW_BRK_TYPE_DABR);
dabrx = ((brk->type >> 3) & 0x7);
if (ppc_md.set_dabr)
return ppc_md.set_dabr(dabr, dabrx);
return __set_dabr(dabr, dabrx);
}
powerpc: Add the DAWR support to the set_break() This adds DAWR supoprt to the set_break(). It does both bare metal and PAPR versions of setting the DAWR. There is still some work we can do to make full use of the watchpoint but that will come later. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:45 +08:00
static inline int set_dawr(struct arch_hw_breakpoint *brk)
{
powerpc: Add length setting to set_dawr Currently we set the length field in the DAWR to 0 which defaults it to one double word (64bits) which is the same as the DABR. Change this so that we can set it to longer values as supported by the DAWR. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-24 23:02:58 +08:00
unsigned long dawr, dawrx, mrd;
powerpc: Add the DAWR support to the set_break() This adds DAWR supoprt to the set_break(). It does both bare metal and PAPR versions of setting the DAWR. There is still some work we can do to make full use of the watchpoint but that will come later. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:45 +08:00
dawr = brk->address;
dawrx = (brk->type & (HW_BRK_TYPE_READ | HW_BRK_TYPE_WRITE)) \
<< (63 - 58); //* read/write bits */
dawrx |= ((brk->type & (HW_BRK_TYPE_TRANSLATE)) >> 2) \
<< (63 - 59); //* translate */
dawrx |= (brk->type & (HW_BRK_TYPE_PRIV_ALL)) \
>> 3; //* PRIM bits */
powerpc: Add length setting to set_dawr Currently we set the length field in the DAWR to 0 which defaults it to one double word (64bits) which is the same as the DABR. Change this so that we can set it to longer values as supported by the DAWR. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-24 23:02:58 +08:00
/* dawr length is stored in field MDR bits 48:53. Matches range in
doublewords (64 bits) baised by -1 eg. 0b000000=1DW and
0b111111=64DW.
brk->len is in bytes.
This aligns up to double word size, shifts and does the bias.
*/
mrd = ((brk->len + 7) >> 3) - 1;
dawrx |= (mrd & 0x3f) << (63 - 53);
powerpc: Add the DAWR support to the set_break() This adds DAWR supoprt to the set_break(). It does both bare metal and PAPR versions of setting the DAWR. There is still some work we can do to make full use of the watchpoint but that will come later. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:45 +08:00
if (ppc_md.set_dawr)
return ppc_md.set_dawr(dawr, dawrx);
mtspr(SPRN_DAWR, dawr);
mtspr(SPRN_DAWRX, dawrx);
return 0;
}
powerpc: Fix smp_processor_id() in preemptible splat in set_breakpoint Currently, on 8641D, which doesn't set CONFIG_HAVE_HW_BREAKPOINT we get the following splat: BUG: using smp_processor_id() in preemptible [00000000] code: login/1382 caller is set_breakpoint+0x1c/0xa0 CPU: 0 PID: 1382 Comm: login Not tainted 3.15.0-rc3-00041-g2aafe1a4d451 #1 Call Trace: [decd5d80] [c0008dc4] show_stack+0x50/0x158 (unreliable) [decd5dc0] [c03c6fa0] dump_stack+0x7c/0xdc [decd5de0] [c01f8818] check_preemption_disabled+0xf4/0x104 [decd5e00] [c00086b8] set_breakpoint+0x1c/0xa0 [decd5e10] [c00d4530] flush_old_exec+0x2bc/0x588 [decd5e40] [c011c468] load_elf_binary+0x2ac/0x1164 [decd5ec0] [c00d35f8] search_binary_handler+0xc4/0x1f8 [decd5ef0] [c00d4ee8] do_execve+0x3d8/0x4b8 [decd5f40] [c001185c] ret_from_syscall+0x0/0x38 --- Exception: c01 at 0xfeee554 LR = 0xfeee7d4 The call path in this case is: flush_thread --> set_debug_reg_defaults --> set_breakpoint --> __get_cpu_var Since preemption is enabled in the cleanup of flush thread, and there is no need to disable it, introduce the distinction between set_breakpoint and __set_breakpoint, leaving only the flush_thread instance as the current user of set_breakpoint. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-04-30 03:25:17 +08:00
void __set_breakpoint(struct arch_hw_breakpoint *brk)
powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:44 +08:00
{
powerpc: Replace __get_cpu_var uses This still has not been merged and now powerpc is the only arch that does not have this change. Sorry about missing linuxppc-dev before. V2->V2 - Fix up to work against 3.18-rc1 __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> Signed-off-by: Christoph Lameter <cl@linux.com> [mpe: Fix build errors caused by set/or_softirq_pending(), and rework assignment in __set_breakpoint() to use memcpy().] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-22 04:23:25 +08:00
memcpy(this_cpu_ptr(&current_brk), brk, sizeof(*brk));
powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:44 +08:00
powerpc: Add the DAWR support to the set_break() This adds DAWR supoprt to the set_break(). It does both bare metal and PAPR versions of setting the DAWR. There is still some work we can do to make full use of the watchpoint but that will come later. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:45 +08:00
if (cpu_has_feature(CPU_FTR_DAWR))
powerpc: Drop return value from set_breakpoint as it is unused None of the callers check the return value, so it might as well not have one at all. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-04-30 03:25:16 +08:00
set_dawr(brk);
else
set_dabr(brk);
powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:44 +08:00
}
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
powerpc: Fix smp_processor_id() in preemptible splat in set_breakpoint Currently, on 8641D, which doesn't set CONFIG_HAVE_HW_BREAKPOINT we get the following splat: BUG: using smp_processor_id() in preemptible [00000000] code: login/1382 caller is set_breakpoint+0x1c/0xa0 CPU: 0 PID: 1382 Comm: login Not tainted 3.15.0-rc3-00041-g2aafe1a4d451 #1 Call Trace: [decd5d80] [c0008dc4] show_stack+0x50/0x158 (unreliable) [decd5dc0] [c03c6fa0] dump_stack+0x7c/0xdc [decd5de0] [c01f8818] check_preemption_disabled+0xf4/0x104 [decd5e00] [c00086b8] set_breakpoint+0x1c/0xa0 [decd5e10] [c00d4530] flush_old_exec+0x2bc/0x588 [decd5e40] [c011c468] load_elf_binary+0x2ac/0x1164 [decd5ec0] [c00d35f8] search_binary_handler+0xc4/0x1f8 [decd5ef0] [c00d4ee8] do_execve+0x3d8/0x4b8 [decd5f40] [c001185c] ret_from_syscall+0x0/0x38 --- Exception: c01 at 0xfeee554 LR = 0xfeee7d4 The call path in this case is: flush_thread --> set_debug_reg_defaults --> set_breakpoint --> __get_cpu_var Since preemption is enabled in the cleanup of flush thread, and there is no need to disable it, introduce the distinction between set_breakpoint and __set_breakpoint, leaving only the flush_thread instance as the current user of set_breakpoint. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-04-30 03:25:17 +08:00
void set_breakpoint(struct arch_hw_breakpoint *brk)
{
preempt_disable();
__set_breakpoint(brk);
preempt_enable();
}
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
#ifdef CONFIG_PPC64
DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
#endif
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:44 +08:00
static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
struct arch_hw_breakpoint *b)
{
if (a->address != b->address)
return false;
if (a->type != b->type)
return false;
if (a->len != b->len)
return false;
return true;
}
powerpc: Don't corrupt transactional state when using FP/VMX in kernel Currently, when we have a process using the transactional memory facilities on POWER8 (that is, the processor is in transactional or suspended state), and the process enters the kernel and the kernel then uses the floating-point or vector (VMX/Altivec) facility, we end up corrupting the user-visible FP/VMX/VSX state. This happens, for example, if a page fault causes a copy-on-write operation, because the copy_page function will use VMX to do the copy on POWER8. The test program below demonstrates the bug. The bug happens because when FP/VMX state for a transactional process is stored in the thread_struct, we store the checkpointed state in .fp_state/.vr_state and the transactional (current) state in .transact_fp/.transact_vr. However, when the kernel wants to use FP/VMX, it calls enable_kernel_fp() or enable_kernel_altivec(), which saves the current state in .fp_state/.vr_state. Furthermore, when we return to the user process we return with FP/VMX/VSX disabled. The next time the process uses FP/VMX/VSX, we don't know which set of state (the current register values, .fp_state/.vr_state, or .transact_fp/.transact_vr) we should be using, since we have no way to tell if we are still in the same transaction, and if not, whether the previous transaction succeeded or failed. Thus it is necessary to strictly adhere to the rule that if FP has been enabled at any point in a transaction, we must keep FP enabled for the user process with the current transactional state in the FP registers, until we detect that it is no longer in a transaction. Similarly for VMX; once enabled it must stay enabled until the process is no longer transactional. In order to keep this rule, we add a new thread_info flag which we test when returning from the kernel to userspace, called TIF_RESTORE_TM. This flag indicates that there is FP/VMX/VSX state to be restored before entering userspace, and when it is set the .tm_orig_msr field in the thread_struct indicates what state needs to be restored. The restoration is done by restore_tm_state(). The TIF_RESTORE_TM bit is set by new giveup_fpu/altivec_maybe_transactional helpers, which are called from enable_kernel_fp/altivec, giveup_vsx, and flush_fp/altivec_to_thread instead of giveup_fpu/altivec. The other thing to be done is to get the transactional FP/VMX/VSX state from .fp_state/.vr_state when doing reclaim, if that state has been saved there by giveup_fpu/altivec_maybe_transactional. Having done this, we set the FP/VMX bit in the thread's MSR after reclaim to indicate that that part of the state is now valid (having been reclaimed from the processor's checkpointed state). Finally, in the signal handling code, we move the clearing of the transactional state bits in the thread's MSR a bit earlier, before calling flush_fp_to_thread(), so that we don't unnecessarily set the TIF_RESTORE_TM bit. This is the test program: /* Michael Neuling 4/12/2013 * * See if the altivec state is leaked out of an aborted transaction due to * kernel vmx copy loops. * * gcc -m64 htm_vmxcopy.c -o htm_vmxcopy * */ /* We don't use all of these, but for reference: */ int main(int argc, char *argv[]) { long double vecin = 1.3; long double vecout; unsigned long pgsize = getpagesize(); int i; int fd; int size = pgsize*16; char tmpfile[] = "/tmp/page_faultXXXXXX"; char buf[pgsize]; char *a; uint64_t aborted = 0; fd = mkstemp(tmpfile); assert(fd >= 0); memset(buf, 0, pgsize); for (i = 0; i < size; i += pgsize) assert(write(fd, buf, pgsize) == pgsize); unlink(tmpfile); a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); assert(a != MAP_FAILED); asm __volatile__( "lxvd2x 40,0,%[vecinptr] ; " // set 40 to initial value TBEGIN "beq 3f ;" TSUSPEND "xxlxor 40,40,40 ; " // set 40 to 0 "std 5, 0(%[map]) ;" // cause kernel vmx copy page TABORT TRESUME TEND "li %[res], 0 ;" "b 5f ;" "3: ;" // Abort handler "li %[res], 1 ;" "5: ;" "stxvd2x 40,0,%[vecoutptr] ; " : [res]"=r"(aborted) : [vecinptr]"r"(&vecin), [vecoutptr]"r"(&vecout), [map]"r"(a) : "memory", "r0", "r3", "r4", "r5", "r6", "r7"); if (aborted && (vecin != vecout)){ printf("FAILED: vector state leaked on abort %f != %f\n", (double)vecin, (double)vecout); exit(1); } munmap(a, size); close(fd); printf("PASSED!\n"); return 0; } Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-13 12:56:29 +08:00
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes When we switch out a task, we need to save both the checkpointed and the speculated state into the thread struct. Similarly when we are switching in a task we need to load both the checkpointed and speculated state. If the task was using FP, we non-lazily reload both the original and the speculative FP register states. This is because the kernel doesn't see if/when a TM rollback occurs, so if we take an FP unavoidable later, we are unable to determine which set of FP regs need to be restored. This simply adds these functions. It doesn't hook them into the existing code yet. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:37 +08:00
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
powerpc: tm: Enable transactional memory (TM) lazily for userspace Currently the MSR TM bit is always set if the hardware is TM capable. This adds extra overhead as it means the TM SPRS (TFHAR, TEXASR and TFAIR) must be swapped for each process regardless of if they use TM. For processes that don't use TM the TM MSR bit can be turned off allowing the kernel to avoid the expensive swap of the TM registers. A TM unavailable exception will occur if a thread does use TM and the kernel will enable MSR_TM and leave it so for some time afterwards. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-14 16:02:16 +08:00
static inline bool tm_enabled(struct task_struct *tsk)
{
return tsk && tsk->thread.regs && (tsk->thread.regs->msr & MSR_TM);
}
powerpc: Don't corrupt transactional state when using FP/VMX in kernel Currently, when we have a process using the transactional memory facilities on POWER8 (that is, the processor is in transactional or suspended state), and the process enters the kernel and the kernel then uses the floating-point or vector (VMX/Altivec) facility, we end up corrupting the user-visible FP/VMX/VSX state. This happens, for example, if a page fault causes a copy-on-write operation, because the copy_page function will use VMX to do the copy on POWER8. The test program below demonstrates the bug. The bug happens because when FP/VMX state for a transactional process is stored in the thread_struct, we store the checkpointed state in .fp_state/.vr_state and the transactional (current) state in .transact_fp/.transact_vr. However, when the kernel wants to use FP/VMX, it calls enable_kernel_fp() or enable_kernel_altivec(), which saves the current state in .fp_state/.vr_state. Furthermore, when we return to the user process we return with FP/VMX/VSX disabled. The next time the process uses FP/VMX/VSX, we don't know which set of state (the current register values, .fp_state/.vr_state, or .transact_fp/.transact_vr) we should be using, since we have no way to tell if we are still in the same transaction, and if not, whether the previous transaction succeeded or failed. Thus it is necessary to strictly adhere to the rule that if FP has been enabled at any point in a transaction, we must keep FP enabled for the user process with the current transactional state in the FP registers, until we detect that it is no longer in a transaction. Similarly for VMX; once enabled it must stay enabled until the process is no longer transactional. In order to keep this rule, we add a new thread_info flag which we test when returning from the kernel to userspace, called TIF_RESTORE_TM. This flag indicates that there is FP/VMX/VSX state to be restored before entering userspace, and when it is set the .tm_orig_msr field in the thread_struct indicates what state needs to be restored. The restoration is done by restore_tm_state(). The TIF_RESTORE_TM bit is set by new giveup_fpu/altivec_maybe_transactional helpers, which are called from enable_kernel_fp/altivec, giveup_vsx, and flush_fp/altivec_to_thread instead of giveup_fpu/altivec. The other thing to be done is to get the transactional FP/VMX/VSX state from .fp_state/.vr_state when doing reclaim, if that state has been saved there by giveup_fpu/altivec_maybe_transactional. Having done this, we set the FP/VMX bit in the thread's MSR after reclaim to indicate that that part of the state is now valid (having been reclaimed from the processor's checkpointed state). Finally, in the signal handling code, we move the clearing of the transactional state bits in the thread's MSR a bit earlier, before calling flush_fp_to_thread(), so that we don't unnecessarily set the TIF_RESTORE_TM bit. This is the test program: /* Michael Neuling 4/12/2013 * * See if the altivec state is leaked out of an aborted transaction due to * kernel vmx copy loops. * * gcc -m64 htm_vmxcopy.c -o htm_vmxcopy * */ /* We don't use all of these, but for reference: */ int main(int argc, char *argv[]) { long double vecin = 1.3; long double vecout; unsigned long pgsize = getpagesize(); int i; int fd; int size = pgsize*16; char tmpfile[] = "/tmp/page_faultXXXXXX"; char buf[pgsize]; char *a; uint64_t aborted = 0; fd = mkstemp(tmpfile); assert(fd >= 0); memset(buf, 0, pgsize); for (i = 0; i < size; i += pgsize) assert(write(fd, buf, pgsize) == pgsize); unlink(tmpfile); a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); assert(a != MAP_FAILED); asm __volatile__( "lxvd2x 40,0,%[vecinptr] ; " // set 40 to initial value TBEGIN "beq 3f ;" TSUSPEND "xxlxor 40,40,40 ; " // set 40 to 0 "std 5, 0(%[map]) ;" // cause kernel vmx copy page TABORT TRESUME TEND "li %[res], 0 ;" "b 5f ;" "3: ;" // Abort handler "li %[res], 1 ;" "5: ;" "stxvd2x 40,0,%[vecoutptr] ; " : [res]"=r"(aborted) : [vecinptr]"r"(&vecin), [vecoutptr]"r"(&vecout), [map]"r"(a) : "memory", "r0", "r3", "r4", "r5", "r6", "r7"); if (aborted && (vecin != vecout)){ printf("FAILED: vector state leaked on abort %f != %f\n", (double)vecin, (double)vecout); exit(1); } munmap(a, size); close(fd); printf("PASSED!\n"); return 0; } Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-13 12:56:29 +08:00
static void tm_reclaim_thread(struct thread_struct *thr,
struct thread_info *ti, uint8_t cause)
{
powerpc/tm: Check for already reclaimed tasks Currently we can hit a scenario where we'll tm_reclaim() twice. This results in a TM bad thing exception because the second reclaim occurs when not in suspend mode. The scenario in which this can happen is the following. We attempt to deliver a signal to userspace. To do this we need obtain the stack pointer to write the signal context. To get this stack pointer we must tm_reclaim() in case we need to use the checkpointed stack pointer (see get_tm_stackpointer()). Normally we'd then return directly to userspace to deliver the signal without going through __switch_to(). Unfortunatley, if at this point we get an error (such as a bad userspace stack pointer), we need to exit the process. The exit will result in a __switch_to(). __switch_to() will attempt to save the process state which results in another tm_reclaim(). This tm_reclaim() now causes a TM Bad Thing exception as this state has already been saved and the processor is no longer in TM suspend mode. Whee! This patch checks the state of the MSR to ensure we are TM suspended before we attempt the tm_reclaim(). If we've already saved the state away, we should no longer be in TM suspend mode. This has the additional advantage of checking for a potential TM Bad Thing exception. Found using syscall fuzzer. Fixes: fb09692e71f1 ("powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes") Cc: stable@vger.kernel.org # v3.9+ Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-11-19 12:44:45 +08:00
/*
* Use the current MSR TM suspended bit to track if we have
* checkpointed state outstanding.
* On signal delivery, we'd normally reclaim the checkpointed
* state to obtain stack pointer (see:get_tm_stackpointer()).
* This will then directly return to userspace without going
* through __switch_to(). However, if the stack frame is bad,
* we need to exit this thread which calls __switch_to() which
* will again attempt to reclaim the already saved tm state.
* Hence we need to check that we've not already reclaimed
* this state.
* We do this using the current MSR, rather tracking it in
* some specific thread_struct bit, as it has the additional
powerpc: Various typo fixes Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-06-01 14:34:37 +08:00
* benefit of checking for a potential TM bad thing exception.
powerpc/tm: Check for already reclaimed tasks Currently we can hit a scenario where we'll tm_reclaim() twice. This results in a TM bad thing exception because the second reclaim occurs when not in suspend mode. The scenario in which this can happen is the following. We attempt to deliver a signal to userspace. To do this we need obtain the stack pointer to write the signal context. To get this stack pointer we must tm_reclaim() in case we need to use the checkpointed stack pointer (see get_tm_stackpointer()). Normally we'd then return directly to userspace to deliver the signal without going through __switch_to(). Unfortunatley, if at this point we get an error (such as a bad userspace stack pointer), we need to exit the process. The exit will result in a __switch_to(). __switch_to() will attempt to save the process state which results in another tm_reclaim(). This tm_reclaim() now causes a TM Bad Thing exception as this state has already been saved and the processor is no longer in TM suspend mode. Whee! This patch checks the state of the MSR to ensure we are TM suspended before we attempt the tm_reclaim(). If we've already saved the state away, we should no longer be in TM suspend mode. This has the additional advantage of checking for a potential TM Bad Thing exception. Found using syscall fuzzer. Fixes: fb09692e71f1 ("powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes") Cc: stable@vger.kernel.org # v3.9+ Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-11-19 12:44:45 +08:00
*/
if (!MSR_TM_SUSPENDED(mfmsr()))
return;
powerpc: tm: Always use fp_state and vr_state to store live registers There is currently an inconsistency as to how the entire CPU register state is saved and restored when a thread uses transactional memory (TM). Using transactional memory results in the CPU having duplicated (almost) all of its register state. This duplication results in a set of registers which can be considered 'live', those being currently modified by the instructions being executed and another set that is frozen at a point in time. On context switch, both sets of state have to be saved and (later) restored. These two states are often called a variety of different things. Common terms for the state which only exists after the CPU has entered a transaction (performed a TBEGIN instruction) in hardware are 'transactional' or 'speculative'. Between a TBEGIN and a TEND or TABORT (or an event that causes the hardware to abort), regardless of the use of TSUSPEND the transactional state can be referred to as the live state. The second state is often to referred to as the 'checkpointed' state and is a duplication of the live state when the TBEGIN instruction is executed. This state is kept in the hardware and will be rolled back to on transaction failure. Currently all the registers stored in pt_regs are ALWAYS the live registers, that is, when a thread has transactional registers their values are stored in pt_regs and the checkpointed state is in ckpt_regs. A strange opposite is true for fp_state/vr_state. When a thread is non transactional fp_state/vr_state holds the live registers. When a thread has initiated a transaction fp_state/vr_state holds the checkpointed state and transact_fp/transact_vr become the structure which holds the live state (at this point it is a transactional state). This method creates confusion as to where the live state is, in some circumstances it requires extra work to determine where to put the live state and prevents the use of common functions designed (probably before TM) to save the live state. With this patch pt_regs, fp_state and vr_state all represent the same thing and the other structures [pending rename] are for checkpointed state. Acked-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:24 +08:00
giveup_all(container_of(thr, struct task_struct, thread));
powerpc: Don't corrupt transactional state when using FP/VMX in kernel Currently, when we have a process using the transactional memory facilities on POWER8 (that is, the processor is in transactional or suspended state), and the process enters the kernel and the kernel then uses the floating-point or vector (VMX/Altivec) facility, we end up corrupting the user-visible FP/VMX/VSX state. This happens, for example, if a page fault causes a copy-on-write operation, because the copy_page function will use VMX to do the copy on POWER8. The test program below demonstrates the bug. The bug happens because when FP/VMX state for a transactional process is stored in the thread_struct, we store the checkpointed state in .fp_state/.vr_state and the transactional (current) state in .transact_fp/.transact_vr. However, when the kernel wants to use FP/VMX, it calls enable_kernel_fp() or enable_kernel_altivec(), which saves the current state in .fp_state/.vr_state. Furthermore, when we return to the user process we return with FP/VMX/VSX disabled. The next time the process uses FP/VMX/VSX, we don't know which set of state (the current register values, .fp_state/.vr_state, or .transact_fp/.transact_vr) we should be using, since we have no way to tell if we are still in the same transaction, and if not, whether the previous transaction succeeded or failed. Thus it is necessary to strictly adhere to the rule that if FP has been enabled at any point in a transaction, we must keep FP enabled for the user process with the current transactional state in the FP registers, until we detect that it is no longer in a transaction. Similarly for VMX; once enabled it must stay enabled until the process is no longer transactional. In order to keep this rule, we add a new thread_info flag which we test when returning from the kernel to userspace, called TIF_RESTORE_TM. This flag indicates that there is FP/VMX/VSX state to be restored before entering userspace, and when it is set the .tm_orig_msr field in the thread_struct indicates what state needs to be restored. The restoration is done by restore_tm_state(). The TIF_RESTORE_TM bit is set by new giveup_fpu/altivec_maybe_transactional helpers, which are called from enable_kernel_fp/altivec, giveup_vsx, and flush_fp/altivec_to_thread instead of giveup_fpu/altivec. The other thing to be done is to get the transactional FP/VMX/VSX state from .fp_state/.vr_state when doing reclaim, if that state has been saved there by giveup_fpu/altivec_maybe_transactional. Having done this, we set the FP/VMX bit in the thread's MSR after reclaim to indicate that that part of the state is now valid (having been reclaimed from the processor's checkpointed state). Finally, in the signal handling code, we move the clearing of the transactional state bits in the thread's MSR a bit earlier, before calling flush_fp_to_thread(), so that we don't unnecessarily set the TIF_RESTORE_TM bit. This is the test program: /* Michael Neuling 4/12/2013 * * See if the altivec state is leaked out of an aborted transaction due to * kernel vmx copy loops. * * gcc -m64 htm_vmxcopy.c -o htm_vmxcopy * */ /* We don't use all of these, but for reference: */ int main(int argc, char *argv[]) { long double vecin = 1.3; long double vecout; unsigned long pgsize = getpagesize(); int i; int fd; int size = pgsize*16; char tmpfile[] = "/tmp/page_faultXXXXXX"; char buf[pgsize]; char *a; uint64_t aborted = 0; fd = mkstemp(tmpfile); assert(fd >= 0); memset(buf, 0, pgsize); for (i = 0; i < size; i += pgsize) assert(write(fd, buf, pgsize) == pgsize); unlink(tmpfile); a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); assert(a != MAP_FAILED); asm __volatile__( "lxvd2x 40,0,%[vecinptr] ; " // set 40 to initial value TBEGIN "beq 3f ;" TSUSPEND "xxlxor 40,40,40 ; " // set 40 to 0 "std 5, 0(%[map]) ;" // cause kernel vmx copy page TABORT TRESUME TEND "li %[res], 0 ;" "b 5f ;" "3: ;" // Abort handler "li %[res], 1 ;" "5: ;" "stxvd2x 40,0,%[vecoutptr] ; " : [res]"=r"(aborted) : [vecinptr]"r"(&vecin), [vecoutptr]"r"(&vecout), [map]"r"(a) : "memory", "r0", "r3", "r4", "r5", "r6", "r7"); if (aborted && (vecin != vecout)){ printf("FAILED: vector state leaked on abort %f != %f\n", (double)vecin, (double)vecout); exit(1); } munmap(a, size); close(fd); printf("PASSED!\n"); return 0; } Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-13 12:56:29 +08:00
powerpc: tm: Always use fp_state and vr_state to store live registers There is currently an inconsistency as to how the entire CPU register state is saved and restored when a thread uses transactional memory (TM). Using transactional memory results in the CPU having duplicated (almost) all of its register state. This duplication results in a set of registers which can be considered 'live', those being currently modified by the instructions being executed and another set that is frozen at a point in time. On context switch, both sets of state have to be saved and (later) restored. These two states are often called a variety of different things. Common terms for the state which only exists after the CPU has entered a transaction (performed a TBEGIN instruction) in hardware are 'transactional' or 'speculative'. Between a TBEGIN and a TEND or TABORT (or an event that causes the hardware to abort), regardless of the use of TSUSPEND the transactional state can be referred to as the live state. The second state is often to referred to as the 'checkpointed' state and is a duplication of the live state when the TBEGIN instruction is executed. This state is kept in the hardware and will be rolled back to on transaction failure. Currently all the registers stored in pt_regs are ALWAYS the live registers, that is, when a thread has transactional registers their values are stored in pt_regs and the checkpointed state is in ckpt_regs. A strange opposite is true for fp_state/vr_state. When a thread is non transactional fp_state/vr_state holds the live registers. When a thread has initiated a transaction fp_state/vr_state holds the checkpointed state and transact_fp/transact_vr become the structure which holds the live state (at this point it is a transactional state). This method creates confusion as to where the live state is, in some circumstances it requires extra work to determine where to put the live state and prevents the use of common functions designed (probably before TM) to save the live state. With this patch pt_regs, fp_state and vr_state all represent the same thing and the other structures [pending rename] are for checkpointed state. Acked-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:24 +08:00
tm_reclaim(thr, thr->ckpt_regs.msr, cause);
powerpc: Don't corrupt transactional state when using FP/VMX in kernel Currently, when we have a process using the transactional memory facilities on POWER8 (that is, the processor is in transactional or suspended state), and the process enters the kernel and the kernel then uses the floating-point or vector (VMX/Altivec) facility, we end up corrupting the user-visible FP/VMX/VSX state. This happens, for example, if a page fault causes a copy-on-write operation, because the copy_page function will use VMX to do the copy on POWER8. The test program below demonstrates the bug. The bug happens because when FP/VMX state for a transactional process is stored in the thread_struct, we store the checkpointed state in .fp_state/.vr_state and the transactional (current) state in .transact_fp/.transact_vr. However, when the kernel wants to use FP/VMX, it calls enable_kernel_fp() or enable_kernel_altivec(), which saves the current state in .fp_state/.vr_state. Furthermore, when we return to the user process we return with FP/VMX/VSX disabled. The next time the process uses FP/VMX/VSX, we don't know which set of state (the current register values, .fp_state/.vr_state, or .transact_fp/.transact_vr) we should be using, since we have no way to tell if we are still in the same transaction, and if not, whether the previous transaction succeeded or failed. Thus it is necessary to strictly adhere to the rule that if FP has been enabled at any point in a transaction, we must keep FP enabled for the user process with the current transactional state in the FP registers, until we detect that it is no longer in a transaction. Similarly for VMX; once enabled it must stay enabled until the process is no longer transactional. In order to keep this rule, we add a new thread_info flag which we test when returning from the kernel to userspace, called TIF_RESTORE_TM. This flag indicates that there is FP/VMX/VSX state to be restored before entering userspace, and when it is set the .tm_orig_msr field in the thread_struct indicates what state needs to be restored. The restoration is done by restore_tm_state(). The TIF_RESTORE_TM bit is set by new giveup_fpu/altivec_maybe_transactional helpers, which are called from enable_kernel_fp/altivec, giveup_vsx, and flush_fp/altivec_to_thread instead of giveup_fpu/altivec. The other thing to be done is to get the transactional FP/VMX/VSX state from .fp_state/.vr_state when doing reclaim, if that state has been saved there by giveup_fpu/altivec_maybe_transactional. Having done this, we set the FP/VMX bit in the thread's MSR after reclaim to indicate that that part of the state is now valid (having been reclaimed from the processor's checkpointed state). Finally, in the signal handling code, we move the clearing of the transactional state bits in the thread's MSR a bit earlier, before calling flush_fp_to_thread(), so that we don't unnecessarily set the TIF_RESTORE_TM bit. This is the test program: /* Michael Neuling 4/12/2013 * * See if the altivec state is leaked out of an aborted transaction due to * kernel vmx copy loops. * * gcc -m64 htm_vmxcopy.c -o htm_vmxcopy * */ /* We don't use all of these, but for reference: */ int main(int argc, char *argv[]) { long double vecin = 1.3; long double vecout; unsigned long pgsize = getpagesize(); int i; int fd; int size = pgsize*16; char tmpfile[] = "/tmp/page_faultXXXXXX"; char buf[pgsize]; char *a; uint64_t aborted = 0; fd = mkstemp(tmpfile); assert(fd >= 0); memset(buf, 0, pgsize); for (i = 0; i < size; i += pgsize) assert(write(fd, buf, pgsize) == pgsize); unlink(tmpfile); a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); assert(a != MAP_FAILED); asm __volatile__( "lxvd2x 40,0,%[vecinptr] ; " // set 40 to initial value TBEGIN "beq 3f ;" TSUSPEND "xxlxor 40,40,40 ; " // set 40 to 0 "std 5, 0(%[map]) ;" // cause kernel vmx copy page TABORT TRESUME TEND "li %[res], 0 ;" "b 5f ;" "3: ;" // Abort handler "li %[res], 1 ;" "5: ;" "stxvd2x 40,0,%[vecoutptr] ; " : [res]"=r"(aborted) : [vecinptr]"r"(&vecin), [vecoutptr]"r"(&vecout), [map]"r"(a) : "memory", "r0", "r3", "r4", "r5", "r6", "r7"); if (aborted && (vecin != vecout)){ printf("FAILED: vector state leaked on abort %f != %f\n", (double)vecin, (double)vecout); exit(1); } munmap(a, size); close(fd); printf("PASSED!\n"); return 0; } Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-13 12:56:29 +08:00
}
void tm_reclaim_current(uint8_t cause)
{
tm_enable();
tm_reclaim_thread(&current->thread, current_thread_info(), cause);
}
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes When we switch out a task, we need to save both the checkpointed and the speculated state into the thread struct. Similarly when we are switching in a task we need to load both the checkpointed and speculated state. If the task was using FP, we non-lazily reload both the original and the speculative FP register states. This is because the kernel doesn't see if/when a TM rollback occurs, so if we take an FP unavoidable later, we are unable to determine which set of FP regs need to be restored. This simply adds these functions. It doesn't hook them into the existing code yet. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:37 +08:00
static inline void tm_reclaim_task(struct task_struct *tsk)
{
/* We have to work out if we're switching from/to a task that's in the
* middle of a transaction.
*
* In switching we need to maintain a 2nd register state as
* oldtask->thread.ckpt_regs. We tm_reclaim(oldproc); this saves the
powerpc: tm: Rename transct_(*) to ck(\1)_state Make the structures being used for checkpointed state named consistently with the pt_regs/ckpt_regs. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:25 +08:00
* checkpointed (tbegin) state in ckpt_regs, ckfp_state and
* ckvr_state
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes When we switch out a task, we need to save both the checkpointed and the speculated state into the thread struct. Similarly when we are switching in a task we need to load both the checkpointed and speculated state. If the task was using FP, we non-lazily reload both the original and the speculative FP register states. This is because the kernel doesn't see if/when a TM rollback occurs, so if we take an FP unavoidable later, we are unable to determine which set of FP regs need to be restored. This simply adds these functions. It doesn't hook them into the existing code yet. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:37 +08:00
*
* We also context switch (save) TFHAR/TEXASR/TFIAR in here.
*/
struct thread_struct *thr = &tsk->thread;
if (!thr->regs)
return;
if (!MSR_TM_ACTIVE(thr->regs->msr))
goto out_and_saveregs;
TM_DEBUG("--- tm_reclaim on pid %d (NIP=%lx, "
"ccr=%lx, msr=%lx, trap=%lx)\n",
tsk->pid, thr->regs->nip,
thr->regs->ccr, thr->regs->msr,
thr->regs->trap);
powerpc: Don't corrupt transactional state when using FP/VMX in kernel Currently, when we have a process using the transactional memory facilities on POWER8 (that is, the processor is in transactional or suspended state), and the process enters the kernel and the kernel then uses the floating-point or vector (VMX/Altivec) facility, we end up corrupting the user-visible FP/VMX/VSX state. This happens, for example, if a page fault causes a copy-on-write operation, because the copy_page function will use VMX to do the copy on POWER8. The test program below demonstrates the bug. The bug happens because when FP/VMX state for a transactional process is stored in the thread_struct, we store the checkpointed state in .fp_state/.vr_state and the transactional (current) state in .transact_fp/.transact_vr. However, when the kernel wants to use FP/VMX, it calls enable_kernel_fp() or enable_kernel_altivec(), which saves the current state in .fp_state/.vr_state. Furthermore, when we return to the user process we return with FP/VMX/VSX disabled. The next time the process uses FP/VMX/VSX, we don't know which set of state (the current register values, .fp_state/.vr_state, or .transact_fp/.transact_vr) we should be using, since we have no way to tell if we are still in the same transaction, and if not, whether the previous transaction succeeded or failed. Thus it is necessary to strictly adhere to the rule that if FP has been enabled at any point in a transaction, we must keep FP enabled for the user process with the current transactional state in the FP registers, until we detect that it is no longer in a transaction. Similarly for VMX; once enabled it must stay enabled until the process is no longer transactional. In order to keep this rule, we add a new thread_info flag which we test when returning from the kernel to userspace, called TIF_RESTORE_TM. This flag indicates that there is FP/VMX/VSX state to be restored before entering userspace, and when it is set the .tm_orig_msr field in the thread_struct indicates what state needs to be restored. The restoration is done by restore_tm_state(). The TIF_RESTORE_TM bit is set by new giveup_fpu/altivec_maybe_transactional helpers, which are called from enable_kernel_fp/altivec, giveup_vsx, and flush_fp/altivec_to_thread instead of giveup_fpu/altivec. The other thing to be done is to get the transactional FP/VMX/VSX state from .fp_state/.vr_state when doing reclaim, if that state has been saved there by giveup_fpu/altivec_maybe_transactional. Having done this, we set the FP/VMX bit in the thread's MSR after reclaim to indicate that that part of the state is now valid (having been reclaimed from the processor's checkpointed state). Finally, in the signal handling code, we move the clearing of the transactional state bits in the thread's MSR a bit earlier, before calling flush_fp_to_thread(), so that we don't unnecessarily set the TIF_RESTORE_TM bit. This is the test program: /* Michael Neuling 4/12/2013 * * See if the altivec state is leaked out of an aborted transaction due to * kernel vmx copy loops. * * gcc -m64 htm_vmxcopy.c -o htm_vmxcopy * */ /* We don't use all of these, but for reference: */ int main(int argc, char *argv[]) { long double vecin = 1.3; long double vecout; unsigned long pgsize = getpagesize(); int i; int fd; int size = pgsize*16; char tmpfile[] = "/tmp/page_faultXXXXXX"; char buf[pgsize]; char *a; uint64_t aborted = 0; fd = mkstemp(tmpfile); assert(fd >= 0); memset(buf, 0, pgsize); for (i = 0; i < size; i += pgsize) assert(write(fd, buf, pgsize) == pgsize); unlink(tmpfile); a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); assert(a != MAP_FAILED); asm __volatile__( "lxvd2x 40,0,%[vecinptr] ; " // set 40 to initial value TBEGIN "beq 3f ;" TSUSPEND "xxlxor 40,40,40 ; " // set 40 to 0 "std 5, 0(%[map]) ;" // cause kernel vmx copy page TABORT TRESUME TEND "li %[res], 0 ;" "b 5f ;" "3: ;" // Abort handler "li %[res], 1 ;" "5: ;" "stxvd2x 40,0,%[vecoutptr] ; " : [res]"=r"(aborted) : [vecinptr]"r"(&vecin), [vecoutptr]"r"(&vecout), [map]"r"(a) : "memory", "r0", "r3", "r4", "r5", "r6", "r7"); if (aborted && (vecin != vecout)){ printf("FAILED: vector state leaked on abort %f != %f\n", (double)vecin, (double)vecout); exit(1); } munmap(a, size); close(fd); printf("PASSED!\n"); return 0; } Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-13 12:56:29 +08:00
tm_reclaim_thread(thr, task_thread_info(tsk), TM_CAUSE_RESCHED);
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes When we switch out a task, we need to save both the checkpointed and the speculated state into the thread struct. Similarly when we are switching in a task we need to load both the checkpointed and speculated state. If the task was using FP, we non-lazily reload both the original and the speculative FP register states. This is because the kernel doesn't see if/when a TM rollback occurs, so if we take an FP unavoidable later, we are unable to determine which set of FP regs need to be restored. This simply adds these functions. It doesn't hook them into the existing code yet. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:37 +08:00
TM_DEBUG("--- tm_reclaim on pid %d complete\n",
tsk->pid);
out_and_saveregs:
/* Always save the regs here, even if a transaction's not active.
* This context-switches a thread's TM info SPRs. We do it here to
* be consistent with the restore path (in recheckpoint) which
* cannot happen later in _switch().
*/
tm_save_sprs(thr);
}
powerpc/tm: Disable IRQ in tm_recheckpoint We can't take an IRQ when we're about to do a trechkpt as our GPR state is set to user GPR values. We've hit this when running some IBM Java stress tests in the lab resulting in the following dump: cpu 0x3f: Vector: 700 (Program Check) at [c000000007eb3d40] pc: c000000000050074: restore_gprs+0xc0/0x148 lr: 00000000b52a8184 sp: ac57d360 msr: 8000000100201030 current = 0xc00000002c500000 paca = 0xc000000007dbfc00 softe: 0 irq_happened: 0x00 pid = 34535, comm = Pooled Thread # R00 = 00000000b52a8184 R16 = 00000000b3e48fda R01 = 00000000ac57d360 R17 = 00000000ade79bd8 R02 = 00000000ac586930 R18 = 000000000fac9bcc R03 = 00000000ade60000 R19 = 00000000ac57f930 R04 = 00000000f6624918 R20 = 00000000ade79be8 R05 = 00000000f663f238 R21 = 00000000ac218a54 R06 = 0000000000000002 R22 = 000000000f956280 R07 = 0000000000000008 R23 = 000000000000007e R08 = 000000000000000a R24 = 000000000000000c R09 = 00000000b6e69160 R25 = 00000000b424cf00 R10 = 0000000000000181 R26 = 00000000f66256d4 R11 = 000000000f365ec0 R27 = 00000000b6fdcdd0 R12 = 00000000f66400f0 R28 = 0000000000000001 R13 = 00000000ada71900 R29 = 00000000ade5a300 R14 = 00000000ac2185a8 R30 = 00000000f663f238 R15 = 0000000000000004 R31 = 00000000f6624918 pc = c000000000050074 restore_gprs+0xc0/0x148 cfar= c00000000004fe28 dont_restore_vec+0x1c/0x1a4 lr = 00000000b52a8184 msr = 8000000100201030 cr = 24804888 ctr = 0000000000000000 xer = 0000000000000000 trap = 700 This moves tm_recheckpoint to a C function and moves the tm_restore_sprs into that function. It then adds IRQ disabling over the trechkpt critical section. It also sets the TEXASR FS in the signals code to ensure this is never set now that we explictly write the TM sprs in tm_recheckpoint. Signed-off-by: Michael Neuling <mikey@neuling.org> cc: stable@vger.kernel.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-04-04 17:19:48 +08:00
extern void __tm_recheckpoint(struct thread_struct *thread,
unsigned long orig_msr);
void tm_recheckpoint(struct thread_struct *thread,
unsigned long orig_msr)
{
unsigned long flags;
powerpc: tm: Enable transactional memory (TM) lazily for userspace Currently the MSR TM bit is always set if the hardware is TM capable. This adds extra overhead as it means the TM SPRS (TFHAR, TEXASR and TFAIR) must be swapped for each process regardless of if they use TM. For processes that don't use TM the TM MSR bit can be turned off allowing the kernel to avoid the expensive swap of the TM registers. A TM unavailable exception will occur if a thread does use TM and the kernel will enable MSR_TM and leave it so for some time afterwards. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-14 16:02:16 +08:00
if (!(thread->regs->msr & MSR_TM))
return;
powerpc/tm: Disable IRQ in tm_recheckpoint We can't take an IRQ when we're about to do a trechkpt as our GPR state is set to user GPR values. We've hit this when running some IBM Java stress tests in the lab resulting in the following dump: cpu 0x3f: Vector: 700 (Program Check) at [c000000007eb3d40] pc: c000000000050074: restore_gprs+0xc0/0x148 lr: 00000000b52a8184 sp: ac57d360 msr: 8000000100201030 current = 0xc00000002c500000 paca = 0xc000000007dbfc00 softe: 0 irq_happened: 0x00 pid = 34535, comm = Pooled Thread # R00 = 00000000b52a8184 R16 = 00000000b3e48fda R01 = 00000000ac57d360 R17 = 00000000ade79bd8 R02 = 00000000ac586930 R18 = 000000000fac9bcc R03 = 00000000ade60000 R19 = 00000000ac57f930 R04 = 00000000f6624918 R20 = 00000000ade79be8 R05 = 00000000f663f238 R21 = 00000000ac218a54 R06 = 0000000000000002 R22 = 000000000f956280 R07 = 0000000000000008 R23 = 000000000000007e R08 = 000000000000000a R24 = 000000000000000c R09 = 00000000b6e69160 R25 = 00000000b424cf00 R10 = 0000000000000181 R26 = 00000000f66256d4 R11 = 000000000f365ec0 R27 = 00000000b6fdcdd0 R12 = 00000000f66400f0 R28 = 0000000000000001 R13 = 00000000ada71900 R29 = 00000000ade5a300 R14 = 00000000ac2185a8 R30 = 00000000f663f238 R15 = 0000000000000004 R31 = 00000000f6624918 pc = c000000000050074 restore_gprs+0xc0/0x148 cfar= c00000000004fe28 dont_restore_vec+0x1c/0x1a4 lr = 00000000b52a8184 msr = 8000000100201030 cr = 24804888 ctr = 0000000000000000 xer = 0000000000000000 trap = 700 This moves tm_recheckpoint to a C function and moves the tm_restore_sprs into that function. It then adds IRQ disabling over the trechkpt critical section. It also sets the TEXASR FS in the signals code to ensure this is never set now that we explictly write the TM sprs in tm_recheckpoint. Signed-off-by: Michael Neuling <mikey@neuling.org> cc: stable@vger.kernel.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-04-04 17:19:48 +08:00
/* We really can't be interrupted here as the TEXASR registers can't
* change and later in the trecheckpoint code, we have a userspace R1.
* So let's hard disable over this region.
*/
local_irq_save(flags);
hard_irq_disable();
/* The TM SPRs are restored here, so that TEXASR.FS can be set
* before the trecheckpoint and no explosion occurs.
*/
tm_restore_sprs(thread);
__tm_recheckpoint(thread, orig_msr);
local_irq_restore(flags);
}
powerpc: Hook in new transactional memory code This hooks the new transactional memory code into context switching, FP/VMX/VMX unavailable and exception return. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:40 +08:00
static inline void tm_recheckpoint_new_task(struct task_struct *new)
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes When we switch out a task, we need to save both the checkpointed and the speculated state into the thread struct. Similarly when we are switching in a task we need to load both the checkpointed and speculated state. If the task was using FP, we non-lazily reload both the original and the speculative FP register states. This is because the kernel doesn't see if/when a TM rollback occurs, so if we take an FP unavoidable later, we are unable to determine which set of FP regs need to be restored. This simply adds these functions. It doesn't hook them into the existing code yet. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:37 +08:00
{
unsigned long msr;
if (!cpu_has_feature(CPU_FTR_TM))
return;
/* Recheckpoint the registers of the thread we're about to switch to.
*
* If the task was using FP, we non-lazily reload both the original and
* the speculative FP register states. This is because the kernel
* doesn't see if/when a TM rollback occurs, so if we take an FP
powerpc: tm: Always use fp_state and vr_state to store live registers There is currently an inconsistency as to how the entire CPU register state is saved and restored when a thread uses transactional memory (TM). Using transactional memory results in the CPU having duplicated (almost) all of its register state. This duplication results in a set of registers which can be considered 'live', those being currently modified by the instructions being executed and another set that is frozen at a point in time. On context switch, both sets of state have to be saved and (later) restored. These two states are often called a variety of different things. Common terms for the state which only exists after the CPU has entered a transaction (performed a TBEGIN instruction) in hardware are 'transactional' or 'speculative'. Between a TBEGIN and a TEND or TABORT (or an event that causes the hardware to abort), regardless of the use of TSUSPEND the transactional state can be referred to as the live state. The second state is often to referred to as the 'checkpointed' state and is a duplication of the live state when the TBEGIN instruction is executed. This state is kept in the hardware and will be rolled back to on transaction failure. Currently all the registers stored in pt_regs are ALWAYS the live registers, that is, when a thread has transactional registers their values are stored in pt_regs and the checkpointed state is in ckpt_regs. A strange opposite is true for fp_state/vr_state. When a thread is non transactional fp_state/vr_state holds the live registers. When a thread has initiated a transaction fp_state/vr_state holds the checkpointed state and transact_fp/transact_vr become the structure which holds the live state (at this point it is a transactional state). This method creates confusion as to where the live state is, in some circumstances it requires extra work to determine where to put the live state and prevents the use of common functions designed (probably before TM) to save the live state. With this patch pt_regs, fp_state and vr_state all represent the same thing and the other structures [pending rename] are for checkpointed state. Acked-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:24 +08:00
* unavailable later, we are unable to determine which set of FP regs
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes When we switch out a task, we need to save both the checkpointed and the speculated state into the thread struct. Similarly when we are switching in a task we need to load both the checkpointed and speculated state. If the task was using FP, we non-lazily reload both the original and the speculative FP register states. This is because the kernel doesn't see if/when a TM rollback occurs, so if we take an FP unavoidable later, we are unable to determine which set of FP regs need to be restored. This simply adds these functions. It doesn't hook them into the existing code yet. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:37 +08:00
* need to be restored.
*/
powerpc: tm: Enable transactional memory (TM) lazily for userspace Currently the MSR TM bit is always set if the hardware is TM capable. This adds extra overhead as it means the TM SPRS (TFHAR, TEXASR and TFAIR) must be swapped for each process regardless of if they use TM. For processes that don't use TM the TM MSR bit can be turned off allowing the kernel to avoid the expensive swap of the TM registers. A TM unavailable exception will occur if a thread does use TM and the kernel will enable MSR_TM and leave it so for some time afterwards. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-14 16:02:16 +08:00
if (!tm_enabled(new))
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes When we switch out a task, we need to save both the checkpointed and the speculated state into the thread struct. Similarly when we are switching in a task we need to load both the checkpointed and speculated state. If the task was using FP, we non-lazily reload both the original and the speculative FP register states. This is because the kernel doesn't see if/when a TM rollback occurs, so if we take an FP unavoidable later, we are unable to determine which set of FP regs need to be restored. This simply adds these functions. It doesn't hook them into the existing code yet. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:37 +08:00
return;
powerpc/tm: Disable IRQ in tm_recheckpoint We can't take an IRQ when we're about to do a trechkpt as our GPR state is set to user GPR values. We've hit this when running some IBM Java stress tests in the lab resulting in the following dump: cpu 0x3f: Vector: 700 (Program Check) at [c000000007eb3d40] pc: c000000000050074: restore_gprs+0xc0/0x148 lr: 00000000b52a8184 sp: ac57d360 msr: 8000000100201030 current = 0xc00000002c500000 paca = 0xc000000007dbfc00 softe: 0 irq_happened: 0x00 pid = 34535, comm = Pooled Thread # R00 = 00000000b52a8184 R16 = 00000000b3e48fda R01 = 00000000ac57d360 R17 = 00000000ade79bd8 R02 = 00000000ac586930 R18 = 000000000fac9bcc R03 = 00000000ade60000 R19 = 00000000ac57f930 R04 = 00000000f6624918 R20 = 00000000ade79be8 R05 = 00000000f663f238 R21 = 00000000ac218a54 R06 = 0000000000000002 R22 = 000000000f956280 R07 = 0000000000000008 R23 = 000000000000007e R08 = 000000000000000a R24 = 000000000000000c R09 = 00000000b6e69160 R25 = 00000000b424cf00 R10 = 0000000000000181 R26 = 00000000f66256d4 R11 = 000000000f365ec0 R27 = 00000000b6fdcdd0 R12 = 00000000f66400f0 R28 = 0000000000000001 R13 = 00000000ada71900 R29 = 00000000ade5a300 R14 = 00000000ac2185a8 R30 = 00000000f663f238 R15 = 0000000000000004 R31 = 00000000f6624918 pc = c000000000050074 restore_gprs+0xc0/0x148 cfar= c00000000004fe28 dont_restore_vec+0x1c/0x1a4 lr = 00000000b52a8184 msr = 8000000100201030 cr = 24804888 ctr = 0000000000000000 xer = 0000000000000000 trap = 700 This moves tm_recheckpoint to a C function and moves the tm_restore_sprs into that function. It then adds IRQ disabling over the trechkpt critical section. It also sets the TEXASR FS in the signals code to ensure this is never set now that we explictly write the TM sprs in tm_recheckpoint. Signed-off-by: Michael Neuling <mikey@neuling.org> cc: stable@vger.kernel.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-04-04 17:19:48 +08:00
if (!MSR_TM_ACTIVE(new->thread.regs->msr)){
tm_restore_sprs(&new->thread);
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes When we switch out a task, we need to save both the checkpointed and the speculated state into the thread struct. Similarly when we are switching in a task we need to load both the checkpointed and speculated state. If the task was using FP, we non-lazily reload both the original and the speculative FP register states. This is because the kernel doesn't see if/when a TM rollback occurs, so if we take an FP unavoidable later, we are unable to determine which set of FP regs need to be restored. This simply adds these functions. It doesn't hook them into the existing code yet. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:37 +08:00
return;
powerpc/tm: Disable IRQ in tm_recheckpoint We can't take an IRQ when we're about to do a trechkpt as our GPR state is set to user GPR values. We've hit this when running some IBM Java stress tests in the lab resulting in the following dump: cpu 0x3f: Vector: 700 (Program Check) at [c000000007eb3d40] pc: c000000000050074: restore_gprs+0xc0/0x148 lr: 00000000b52a8184 sp: ac57d360 msr: 8000000100201030 current = 0xc00000002c500000 paca = 0xc000000007dbfc00 softe: 0 irq_happened: 0x00 pid = 34535, comm = Pooled Thread # R00 = 00000000b52a8184 R16 = 00000000b3e48fda R01 = 00000000ac57d360 R17 = 00000000ade79bd8 R02 = 00000000ac586930 R18 = 000000000fac9bcc R03 = 00000000ade60000 R19 = 00000000ac57f930 R04 = 00000000f6624918 R20 = 00000000ade79be8 R05 = 00000000f663f238 R21 = 00000000ac218a54 R06 = 0000000000000002 R22 = 000000000f956280 R07 = 0000000000000008 R23 = 000000000000007e R08 = 000000000000000a R24 = 000000000000000c R09 = 00000000b6e69160 R25 = 00000000b424cf00 R10 = 0000000000000181 R26 = 00000000f66256d4 R11 = 000000000f365ec0 R27 = 00000000b6fdcdd0 R12 = 00000000f66400f0 R28 = 0000000000000001 R13 = 00000000ada71900 R29 = 00000000ade5a300 R14 = 00000000ac2185a8 R30 = 00000000f663f238 R15 = 0000000000000004 R31 = 00000000f6624918 pc = c000000000050074 restore_gprs+0xc0/0x148 cfar= c00000000004fe28 dont_restore_vec+0x1c/0x1a4 lr = 00000000b52a8184 msr = 8000000100201030 cr = 24804888 ctr = 0000000000000000 xer = 0000000000000000 trap = 700 This moves tm_recheckpoint to a C function and moves the tm_restore_sprs into that function. It then adds IRQ disabling over the trechkpt critical section. It also sets the TEXASR FS in the signals code to ensure this is never set now that we explictly write the TM sprs in tm_recheckpoint. Signed-off-by: Michael Neuling <mikey@neuling.org> cc: stable@vger.kernel.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-04-04 17:19:48 +08:00
}
powerpc/tm: Drop tm_orig_msr from thread_struct Currently tm_orig_msr is getting used during process context switch only. Then there is ckpt_regs which saves the checkpointed userspace context The MSR slot contained in ckpt_regs structure can be used during process context switch instead of tm_orig_msr, thus allowing us to drop it from thread_struct structure. This patch does that change. Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-07-06 18:54:10 +08:00
msr = new->thread.ckpt_regs.msr;
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes When we switch out a task, we need to save both the checkpointed and the speculated state into the thread struct. Similarly when we are switching in a task we need to load both the checkpointed and speculated state. If the task was using FP, we non-lazily reload both the original and the speculative FP register states. This is because the kernel doesn't see if/when a TM rollback occurs, so if we take an FP unavoidable later, we are unable to determine which set of FP regs need to be restored. This simply adds these functions. It doesn't hook them into the existing code yet. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:37 +08:00
/* Recheckpoint to restore original checkpointed register state. */
TM_DEBUG("*** tm_recheckpoint of pid %d "
"(new->msr 0x%lx, new->origmsr 0x%lx)\n",
new->pid, new->thread.regs->msr, msr);
tm_recheckpoint(&new->thread, msr);
powerpc: tm: Always use fp_state and vr_state to store live registers There is currently an inconsistency as to how the entire CPU register state is saved and restored when a thread uses transactional memory (TM). Using transactional memory results in the CPU having duplicated (almost) all of its register state. This duplication results in a set of registers which can be considered 'live', those being currently modified by the instructions being executed and another set that is frozen at a point in time. On context switch, both sets of state have to be saved and (later) restored. These two states are often called a variety of different things. Common terms for the state which only exists after the CPU has entered a transaction (performed a TBEGIN instruction) in hardware are 'transactional' or 'speculative'. Between a TBEGIN and a TEND or TABORT (or an event that causes the hardware to abort), regardless of the use of TSUSPEND the transactional state can be referred to as the live state. The second state is often to referred to as the 'checkpointed' state and is a duplication of the live state when the TBEGIN instruction is executed. This state is kept in the hardware and will be rolled back to on transaction failure. Currently all the registers stored in pt_regs are ALWAYS the live registers, that is, when a thread has transactional registers their values are stored in pt_regs and the checkpointed state is in ckpt_regs. A strange opposite is true for fp_state/vr_state. When a thread is non transactional fp_state/vr_state holds the live registers. When a thread has initiated a transaction fp_state/vr_state holds the checkpointed state and transact_fp/transact_vr become the structure which holds the live state (at this point it is a transactional state). This method creates confusion as to where the live state is, in some circumstances it requires extra work to determine where to put the live state and prevents the use of common functions designed (probably before TM) to save the live state. With this patch pt_regs, fp_state and vr_state all represent the same thing and the other structures [pending rename] are for checkpointed state. Acked-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:24 +08:00
/*
* The checkpointed state has been restored but the live state has
* not, ensure all the math functionality is turned off to trigger
* restore_math() to reload.
*/
new->thread.regs->msr &= ~(MSR_FP | MSR_VEC | MSR_VSX);
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes When we switch out a task, we need to save both the checkpointed and the speculated state into the thread struct. Similarly when we are switching in a task we need to load both the checkpointed and speculated state. If the task was using FP, we non-lazily reload both the original and the speculative FP register states. This is because the kernel doesn't see if/when a TM rollback occurs, so if we take an FP unavoidable later, we are unable to determine which set of FP regs need to be restored. This simply adds these functions. It doesn't hook them into the existing code yet. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:37 +08:00
TM_DEBUG("*** tm_recheckpoint of pid %d complete "
"(kernel msr 0x%lx)\n",
new->pid, mfmsr());
}
powerpc: tm: Always use fp_state and vr_state to store live registers There is currently an inconsistency as to how the entire CPU register state is saved and restored when a thread uses transactional memory (TM). Using transactional memory results in the CPU having duplicated (almost) all of its register state. This duplication results in a set of registers which can be considered 'live', those being currently modified by the instructions being executed and another set that is frozen at a point in time. On context switch, both sets of state have to be saved and (later) restored. These two states are often called a variety of different things. Common terms for the state which only exists after the CPU has entered a transaction (performed a TBEGIN instruction) in hardware are 'transactional' or 'speculative'. Between a TBEGIN and a TEND or TABORT (or an event that causes the hardware to abort), regardless of the use of TSUSPEND the transactional state can be referred to as the live state. The second state is often to referred to as the 'checkpointed' state and is a duplication of the live state when the TBEGIN instruction is executed. This state is kept in the hardware and will be rolled back to on transaction failure. Currently all the registers stored in pt_regs are ALWAYS the live registers, that is, when a thread has transactional registers their values are stored in pt_regs and the checkpointed state is in ckpt_regs. A strange opposite is true for fp_state/vr_state. When a thread is non transactional fp_state/vr_state holds the live registers. When a thread has initiated a transaction fp_state/vr_state holds the checkpointed state and transact_fp/transact_vr become the structure which holds the live state (at this point it is a transactional state). This method creates confusion as to where the live state is, in some circumstances it requires extra work to determine where to put the live state and prevents the use of common functions designed (probably before TM) to save the live state. With this patch pt_regs, fp_state and vr_state all represent the same thing and the other structures [pending rename] are for checkpointed state. Acked-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:24 +08:00
static inline void __switch_to_tm(struct task_struct *prev,
struct task_struct *new)
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes When we switch out a task, we need to save both the checkpointed and the speculated state into the thread struct. Similarly when we are switching in a task we need to load both the checkpointed and speculated state. If the task was using FP, we non-lazily reload both the original and the speculative FP register states. This is because the kernel doesn't see if/when a TM rollback occurs, so if we take an FP unavoidable later, we are unable to determine which set of FP regs need to be restored. This simply adds these functions. It doesn't hook them into the existing code yet. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:37 +08:00
{
if (cpu_has_feature(CPU_FTR_TM)) {
powerpc: tm: Enable transactional memory (TM) lazily for userspace Currently the MSR TM bit is always set if the hardware is TM capable. This adds extra overhead as it means the TM SPRS (TFHAR, TEXASR and TFAIR) must be swapped for each process regardless of if they use TM. For processes that don't use TM the TM MSR bit can be turned off allowing the kernel to avoid the expensive swap of the TM registers. A TM unavailable exception will occur if a thread does use TM and the kernel will enable MSR_TM and leave it so for some time afterwards. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-14 16:02:16 +08:00
if (tm_enabled(prev) || tm_enabled(new))
tm_enable();
if (tm_enabled(prev)) {
prev->thread.load_tm++;
tm_reclaim_task(prev);
if (!MSR_TM_ACTIVE(prev->thread.regs->msr) && prev->thread.load_tm == 0)
prev->thread.regs->msr &= ~MSR_TM;
}
powerpc: tm: Always use fp_state and vr_state to store live registers There is currently an inconsistency as to how the entire CPU register state is saved and restored when a thread uses transactional memory (TM). Using transactional memory results in the CPU having duplicated (almost) all of its register state. This duplication results in a set of registers which can be considered 'live', those being currently modified by the instructions being executed and another set that is frozen at a point in time. On context switch, both sets of state have to be saved and (later) restored. These two states are often called a variety of different things. Common terms for the state which only exists after the CPU has entered a transaction (performed a TBEGIN instruction) in hardware are 'transactional' or 'speculative'. Between a TBEGIN and a TEND or TABORT (or an event that causes the hardware to abort), regardless of the use of TSUSPEND the transactional state can be referred to as the live state. The second state is often to referred to as the 'checkpointed' state and is a duplication of the live state when the TBEGIN instruction is executed. This state is kept in the hardware and will be rolled back to on transaction failure. Currently all the registers stored in pt_regs are ALWAYS the live registers, that is, when a thread has transactional registers their values are stored in pt_regs and the checkpointed state is in ckpt_regs. A strange opposite is true for fp_state/vr_state. When a thread is non transactional fp_state/vr_state holds the live registers. When a thread has initiated a transaction fp_state/vr_state holds the checkpointed state and transact_fp/transact_vr become the structure which holds the live state (at this point it is a transactional state). This method creates confusion as to where the live state is, in some circumstances it requires extra work to determine where to put the live state and prevents the use of common functions designed (probably before TM) to save the live state. With this patch pt_regs, fp_state and vr_state all represent the same thing and the other structures [pending rename] are for checkpointed state. Acked-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:24 +08:00
tm_recheckpoint_new_task(new);
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes When we switch out a task, we need to save both the checkpointed and the speculated state into the thread struct. Similarly when we are switching in a task we need to load both the checkpointed and speculated state. If the task was using FP, we non-lazily reload both the original and the speculative FP register states. This is because the kernel doesn't see if/when a TM rollback occurs, so if we take an FP unavoidable later, we are unable to determine which set of FP regs need to be restored. This simply adds these functions. It doesn't hook them into the existing code yet. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:37 +08:00
}
}
powerpc: Don't corrupt transactional state when using FP/VMX in kernel Currently, when we have a process using the transactional memory facilities on POWER8 (that is, the processor is in transactional or suspended state), and the process enters the kernel and the kernel then uses the floating-point or vector (VMX/Altivec) facility, we end up corrupting the user-visible FP/VMX/VSX state. This happens, for example, if a page fault causes a copy-on-write operation, because the copy_page function will use VMX to do the copy on POWER8. The test program below demonstrates the bug. The bug happens because when FP/VMX state for a transactional process is stored in the thread_struct, we store the checkpointed state in .fp_state/.vr_state and the transactional (current) state in .transact_fp/.transact_vr. However, when the kernel wants to use FP/VMX, it calls enable_kernel_fp() or enable_kernel_altivec(), which saves the current state in .fp_state/.vr_state. Furthermore, when we return to the user process we return with FP/VMX/VSX disabled. The next time the process uses FP/VMX/VSX, we don't know which set of state (the current register values, .fp_state/.vr_state, or .transact_fp/.transact_vr) we should be using, since we have no way to tell if we are still in the same transaction, and if not, whether the previous transaction succeeded or failed. Thus it is necessary to strictly adhere to the rule that if FP has been enabled at any point in a transaction, we must keep FP enabled for the user process with the current transactional state in the FP registers, until we detect that it is no longer in a transaction. Similarly for VMX; once enabled it must stay enabled until the process is no longer transactional. In order to keep this rule, we add a new thread_info flag which we test when returning from the kernel to userspace, called TIF_RESTORE_TM. This flag indicates that there is FP/VMX/VSX state to be restored before entering userspace, and when it is set the .tm_orig_msr field in the thread_struct indicates what state needs to be restored. The restoration is done by restore_tm_state(). The TIF_RESTORE_TM bit is set by new giveup_fpu/altivec_maybe_transactional helpers, which are called from enable_kernel_fp/altivec, giveup_vsx, and flush_fp/altivec_to_thread instead of giveup_fpu/altivec. The other thing to be done is to get the transactional FP/VMX/VSX state from .fp_state/.vr_state when doing reclaim, if that state has been saved there by giveup_fpu/altivec_maybe_transactional. Having done this, we set the FP/VMX bit in the thread's MSR after reclaim to indicate that that part of the state is now valid (having been reclaimed from the processor's checkpointed state). Finally, in the signal handling code, we move the clearing of the transactional state bits in the thread's MSR a bit earlier, before calling flush_fp_to_thread(), so that we don't unnecessarily set the TIF_RESTORE_TM bit. This is the test program: /* Michael Neuling 4/12/2013 * * See if the altivec state is leaked out of an aborted transaction due to * kernel vmx copy loops. * * gcc -m64 htm_vmxcopy.c -o htm_vmxcopy * */ /* We don't use all of these, but for reference: */ int main(int argc, char *argv[]) { long double vecin = 1.3; long double vecout; unsigned long pgsize = getpagesize(); int i; int fd; int size = pgsize*16; char tmpfile[] = "/tmp/page_faultXXXXXX"; char buf[pgsize]; char *a; uint64_t aborted = 0; fd = mkstemp(tmpfile); assert(fd >= 0); memset(buf, 0, pgsize); for (i = 0; i < size; i += pgsize) assert(write(fd, buf, pgsize) == pgsize); unlink(tmpfile); a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); assert(a != MAP_FAILED); asm __volatile__( "lxvd2x 40,0,%[vecinptr] ; " // set 40 to initial value TBEGIN "beq 3f ;" TSUSPEND "xxlxor 40,40,40 ; " // set 40 to 0 "std 5, 0(%[map]) ;" // cause kernel vmx copy page TABORT TRESUME TEND "li %[res], 0 ;" "b 5f ;" "3: ;" // Abort handler "li %[res], 1 ;" "5: ;" "stxvd2x 40,0,%[vecoutptr] ; " : [res]"=r"(aborted) : [vecinptr]"r"(&vecin), [vecoutptr]"r"(&vecout), [map]"r"(a) : "memory", "r0", "r3", "r4", "r5", "r6", "r7"); if (aborted && (vecin != vecout)){ printf("FAILED: vector state leaked on abort %f != %f\n", (double)vecin, (double)vecout); exit(1); } munmap(a, size); close(fd); printf("PASSED!\n"); return 0; } Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-13 12:56:29 +08:00
/*
* This is called if we are on the way out to userspace and the
* TIF_RESTORE_TM flag is set. It checks if we need to reload
* FP and/or vector state and does so if necessary.
* If userspace is inside a transaction (whether active or
* suspended) and FP/VMX/VSX instructions have ever been enabled
* inside that transaction, then we have to keep them enabled
* and keep the FP/VMX/VSX state loaded while ever the transaction
* continues. The reason is that if we didn't, and subsequently
* got a FP/VMX/VSX unavailable interrupt inside a transaction,
* we don't know whether it's the same transaction, and thus we
* don't know which of the checkpointed state and the transactional
* state to use.
*/
void restore_tm_state(struct pt_regs *regs)
{
unsigned long msr_diff;
powerpc: tm: Always use fp_state and vr_state to store live registers There is currently an inconsistency as to how the entire CPU register state is saved and restored when a thread uses transactional memory (TM). Using transactional memory results in the CPU having duplicated (almost) all of its register state. This duplication results in a set of registers which can be considered 'live', those being currently modified by the instructions being executed and another set that is frozen at a point in time. On context switch, both sets of state have to be saved and (later) restored. These two states are often called a variety of different things. Common terms for the state which only exists after the CPU has entered a transaction (performed a TBEGIN instruction) in hardware are 'transactional' or 'speculative'. Between a TBEGIN and a TEND or TABORT (or an event that causes the hardware to abort), regardless of the use of TSUSPEND the transactional state can be referred to as the live state. The second state is often to referred to as the 'checkpointed' state and is a duplication of the live state when the TBEGIN instruction is executed. This state is kept in the hardware and will be rolled back to on transaction failure. Currently all the registers stored in pt_regs are ALWAYS the live registers, that is, when a thread has transactional registers their values are stored in pt_regs and the checkpointed state is in ckpt_regs. A strange opposite is true for fp_state/vr_state. When a thread is non transactional fp_state/vr_state holds the live registers. When a thread has initiated a transaction fp_state/vr_state holds the checkpointed state and transact_fp/transact_vr become the structure which holds the live state (at this point it is a transactional state). This method creates confusion as to where the live state is, in some circumstances it requires extra work to determine where to put the live state and prevents the use of common functions designed (probably before TM) to save the live state. With this patch pt_regs, fp_state and vr_state all represent the same thing and the other structures [pending rename] are for checkpointed state. Acked-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:24 +08:00
/*
* This is the only moment we should clear TIF_RESTORE_TM as
* it is here that ckpt_regs.msr and pt_regs.msr become the same
* again, anything else could lead to an incorrect ckpt_msr being
* saved and therefore incorrect signal contexts.
*/
powerpc: Don't corrupt transactional state when using FP/VMX in kernel Currently, when we have a process using the transactional memory facilities on POWER8 (that is, the processor is in transactional or suspended state), and the process enters the kernel and the kernel then uses the floating-point or vector (VMX/Altivec) facility, we end up corrupting the user-visible FP/VMX/VSX state. This happens, for example, if a page fault causes a copy-on-write operation, because the copy_page function will use VMX to do the copy on POWER8. The test program below demonstrates the bug. The bug happens because when FP/VMX state for a transactional process is stored in the thread_struct, we store the checkpointed state in .fp_state/.vr_state and the transactional (current) state in .transact_fp/.transact_vr. However, when the kernel wants to use FP/VMX, it calls enable_kernel_fp() or enable_kernel_altivec(), which saves the current state in .fp_state/.vr_state. Furthermore, when we return to the user process we return with FP/VMX/VSX disabled. The next time the process uses FP/VMX/VSX, we don't know which set of state (the current register values, .fp_state/.vr_state, or .transact_fp/.transact_vr) we should be using, since we have no way to tell if we are still in the same transaction, and if not, whether the previous transaction succeeded or failed. Thus it is necessary to strictly adhere to the rule that if FP has been enabled at any point in a transaction, we must keep FP enabled for the user process with the current transactional state in the FP registers, until we detect that it is no longer in a transaction. Similarly for VMX; once enabled it must stay enabled until the process is no longer transactional. In order to keep this rule, we add a new thread_info flag which we test when returning from the kernel to userspace, called TIF_RESTORE_TM. This flag indicates that there is FP/VMX/VSX state to be restored before entering userspace, and when it is set the .tm_orig_msr field in the thread_struct indicates what state needs to be restored. The restoration is done by restore_tm_state(). The TIF_RESTORE_TM bit is set by new giveup_fpu/altivec_maybe_transactional helpers, which are called from enable_kernel_fp/altivec, giveup_vsx, and flush_fp/altivec_to_thread instead of giveup_fpu/altivec. The other thing to be done is to get the transactional FP/VMX/VSX state from .fp_state/.vr_state when doing reclaim, if that state has been saved there by giveup_fpu/altivec_maybe_transactional. Having done this, we set the FP/VMX bit in the thread's MSR after reclaim to indicate that that part of the state is now valid (having been reclaimed from the processor's checkpointed state). Finally, in the signal handling code, we move the clearing of the transactional state bits in the thread's MSR a bit earlier, before calling flush_fp_to_thread(), so that we don't unnecessarily set the TIF_RESTORE_TM bit. This is the test program: /* Michael Neuling 4/12/2013 * * See if the altivec state is leaked out of an aborted transaction due to * kernel vmx copy loops. * * gcc -m64 htm_vmxcopy.c -o htm_vmxcopy * */ /* We don't use all of these, but for reference: */ int main(int argc, char *argv[]) { long double vecin = 1.3; long double vecout; unsigned long pgsize = getpagesize(); int i; int fd; int size = pgsize*16; char tmpfile[] = "/tmp/page_faultXXXXXX"; char buf[pgsize]; char *a; uint64_t aborted = 0; fd = mkstemp(tmpfile); assert(fd >= 0); memset(buf, 0, pgsize); for (i = 0; i < size; i += pgsize) assert(write(fd, buf, pgsize) == pgsize); unlink(tmpfile); a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); assert(a != MAP_FAILED); asm __volatile__( "lxvd2x 40,0,%[vecinptr] ; " // set 40 to initial value TBEGIN "beq 3f ;" TSUSPEND "xxlxor 40,40,40 ; " // set 40 to 0 "std 5, 0(%[map]) ;" // cause kernel vmx copy page TABORT TRESUME TEND "li %[res], 0 ;" "b 5f ;" "3: ;" // Abort handler "li %[res], 1 ;" "5: ;" "stxvd2x 40,0,%[vecoutptr] ; " : [res]"=r"(aborted) : [vecinptr]"r"(&vecin), [vecoutptr]"r"(&vecout), [map]"r"(a) : "memory", "r0", "r3", "r4", "r5", "r6", "r7"); if (aborted && (vecin != vecout)){ printf("FAILED: vector state leaked on abort %f != %f\n", (double)vecin, (double)vecout); exit(1); } munmap(a, size); close(fd); printf("PASSED!\n"); return 0; } Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-13 12:56:29 +08:00
clear_thread_flag(TIF_RESTORE_TM);
if (!MSR_TM_ACTIVE(regs->msr))
return;
powerpc/tm: Drop tm_orig_msr from thread_struct Currently tm_orig_msr is getting used during process context switch only. Then there is ckpt_regs which saves the checkpointed userspace context The MSR slot contained in ckpt_regs structure can be used during process context switch instead of tm_orig_msr, thus allowing us to drop it from thread_struct structure. This patch does that change. Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-07-06 18:54:10 +08:00
msr_diff = current->thread.ckpt_regs.msr & ~regs->msr;
powerpc: Don't corrupt transactional state when using FP/VMX in kernel Currently, when we have a process using the transactional memory facilities on POWER8 (that is, the processor is in transactional or suspended state), and the process enters the kernel and the kernel then uses the floating-point or vector (VMX/Altivec) facility, we end up corrupting the user-visible FP/VMX/VSX state. This happens, for example, if a page fault causes a copy-on-write operation, because the copy_page function will use VMX to do the copy on POWER8. The test program below demonstrates the bug. The bug happens because when FP/VMX state for a transactional process is stored in the thread_struct, we store the checkpointed state in .fp_state/.vr_state and the transactional (current) state in .transact_fp/.transact_vr. However, when the kernel wants to use FP/VMX, it calls enable_kernel_fp() or enable_kernel_altivec(), which saves the current state in .fp_state/.vr_state. Furthermore, when we return to the user process we return with FP/VMX/VSX disabled. The next time the process uses FP/VMX/VSX, we don't know which set of state (the current register values, .fp_state/.vr_state, or .transact_fp/.transact_vr) we should be using, since we have no way to tell if we are still in the same transaction, and if not, whether the previous transaction succeeded or failed. Thus it is necessary to strictly adhere to the rule that if FP has been enabled at any point in a transaction, we must keep FP enabled for the user process with the current transactional state in the FP registers, until we detect that it is no longer in a transaction. Similarly for VMX; once enabled it must stay enabled until the process is no longer transactional. In order to keep this rule, we add a new thread_info flag which we test when returning from the kernel to userspace, called TIF_RESTORE_TM. This flag indicates that there is FP/VMX/VSX state to be restored before entering userspace, and when it is set the .tm_orig_msr field in the thread_struct indicates what state needs to be restored. The restoration is done by restore_tm_state(). The TIF_RESTORE_TM bit is set by new giveup_fpu/altivec_maybe_transactional helpers, which are called from enable_kernel_fp/altivec, giveup_vsx, and flush_fp/altivec_to_thread instead of giveup_fpu/altivec. The other thing to be done is to get the transactional FP/VMX/VSX state from .fp_state/.vr_state when doing reclaim, if that state has been saved there by giveup_fpu/altivec_maybe_transactional. Having done this, we set the FP/VMX bit in the thread's MSR after reclaim to indicate that that part of the state is now valid (having been reclaimed from the processor's checkpointed state). Finally, in the signal handling code, we move the clearing of the transactional state bits in the thread's MSR a bit earlier, before calling flush_fp_to_thread(), so that we don't unnecessarily set the TIF_RESTORE_TM bit. This is the test program: /* Michael Neuling 4/12/2013 * * See if the altivec state is leaked out of an aborted transaction due to * kernel vmx copy loops. * * gcc -m64 htm_vmxcopy.c -o htm_vmxcopy * */ /* We don't use all of these, but for reference: */ int main(int argc, char *argv[]) { long double vecin = 1.3; long double vecout; unsigned long pgsize = getpagesize(); int i; int fd; int size = pgsize*16; char tmpfile[] = "/tmp/page_faultXXXXXX"; char buf[pgsize]; char *a; uint64_t aborted = 0; fd = mkstemp(tmpfile); assert(fd >= 0); memset(buf, 0, pgsize); for (i = 0; i < size; i += pgsize) assert(write(fd, buf, pgsize) == pgsize); unlink(tmpfile); a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); assert(a != MAP_FAILED); asm __volatile__( "lxvd2x 40,0,%[vecinptr] ; " // set 40 to initial value TBEGIN "beq 3f ;" TSUSPEND "xxlxor 40,40,40 ; " // set 40 to 0 "std 5, 0(%[map]) ;" // cause kernel vmx copy page TABORT TRESUME TEND "li %[res], 0 ;" "b 5f ;" "3: ;" // Abort handler "li %[res], 1 ;" "5: ;" "stxvd2x 40,0,%[vecoutptr] ; " : [res]"=r"(aborted) : [vecinptr]"r"(&vecin), [vecoutptr]"r"(&vecout), [map]"r"(a) : "memory", "r0", "r3", "r4", "r5", "r6", "r7"); if (aborted && (vecin != vecout)){ printf("FAILED: vector state leaked on abort %f != %f\n", (double)vecin, (double)vecout); exit(1); } munmap(a, size); close(fd); printf("PASSED!\n"); return 0; } Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-13 12:56:29 +08:00
msr_diff &= MSR_FP | MSR_VEC | MSR_VSX;
powerpc: Restore FPU/VEC/VSX if previously used Currently the FPU, VEC and VSX facilities are lazily loaded. This is not a problem unless a process is using these facilities. Modern versions of GCC are very good at automatically vectorising code, new and modernised workloads make use of floating point and vector facilities, even the kernel makes use of vectorised memcpy. All this combined greatly increases the cost of a syscall since the kernel uses the facilities sometimes even in syscall fast-path making it increasingly common for a thread to take an *_unavailable exception soon after a syscall, not to mention potentially taking all three. The obvious overcompensation to this problem is to simply always load all the facilities on every exit to userspace. Loading up all FPU, VEC and VSX registers every time can be expensive and if a workload does avoid using them, it should not be forced to incur this penalty. An 8bit counter is used to detect if the registers have been used in the past and the registers are always loaded until the value wraps to back to zero. Several versions of the assembly in entry_64.S were tested: 1. Always calling C. 2. Performing a common case check and then calling C. 3. A complex check in asm. After some benchmarking it was determined that avoiding C in the common case is a performance benefit (option 2). The full check in asm (option 3) greatly complicated that codepath for a negligible performance gain and the trade-off was deemed not worth it. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> [mpe: Move load_vec in the struct to fill an existing hole, reword change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> fixup
2016-02-29 14:53:47 +08:00
powerpc: Always restore FPU/VEC/VSX if hardware transactional memory in use Comment from arch/powerpc/kernel/process.c:967: If userspace is inside a transaction (whether active or suspended) and FP/VMX/VSX instructions have ever been enabled inside that transaction, then we have to keep them enabled and keep the FP/VMX/VSX state loaded while ever the transaction continues. The reason is that if we didn't, and subsequently got a FP/VMX/VSX unavailable interrupt inside a transaction, we don't know whether it's the same transaction, and thus we don't know which of the checkpointed state and the ransactional state to use. restore_math() restore_fp() and restore_altivec() currently may not restore the registers. It doesn't appear that this is more serious than a performance penalty. If the math registers aren't restored the userspace thread will still be run with the facility disabled. Userspace will not be able to read invalid values. On the first access it will take an facility unavailable exception and the kernel will detected an active transaction, at which point it will abort the transaction. There is the possibility for a pathological case preventing any progress by transactions, however, transactions are never guaranteed to make progress. Fixes: 70fe3d9 ("powerpc: Restore FPU/VEC/VSX if previously used") Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:08 +08:00
/* Ensure that restore_math() will restore */
if (msr_diff & MSR_FP)
current->thread.load_fp = 1;
powerpc/process: Fix CONFIG_ALIVEC typo in restore_tm_state() It should be ALTIVEC, not ALIVEC. Cyril explains: If a thread performs a transaction with altivec and then gets preempted for whatever reason, this bug may cause the kernel to not re-enable altivec when that thread runs again. This will result in an altivec unavailable fault, when that fault happens inside a user transaction the kernel has no choice but to enable altivec and doom the transaction. The result is that transactions using altivec may get aborted more often than they should. The difficulty in catching this with a selftest is my deliberate use of the word may above. Optimisations to avoid FPU/altivec/VSX faults mean that the kernel will always leave them on for 255 switches. This code prevents the kernel turning it off if it got to the 256th switch (and userspace was transactional). Fixes: dc16b553c949 ("powerpc: Always restore FPU/VEC/VSX if hardware transactional memory in use") Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-05 13:57:26 +08:00
#ifdef CONFIG_ALTIVEC
powerpc: Always restore FPU/VEC/VSX if hardware transactional memory in use Comment from arch/powerpc/kernel/process.c:967: If userspace is inside a transaction (whether active or suspended) and FP/VMX/VSX instructions have ever been enabled inside that transaction, then we have to keep them enabled and keep the FP/VMX/VSX state loaded while ever the transaction continues. The reason is that if we didn't, and subsequently got a FP/VMX/VSX unavailable interrupt inside a transaction, we don't know whether it's the same transaction, and thus we don't know which of the checkpointed state and the ransactional state to use. restore_math() restore_fp() and restore_altivec() currently may not restore the registers. It doesn't appear that this is more serious than a performance penalty. If the math registers aren't restored the userspace thread will still be run with the facility disabled. Userspace will not be able to read invalid values. On the first access it will take an facility unavailable exception and the kernel will detected an active transaction, at which point it will abort the transaction. There is the possibility for a pathological case preventing any progress by transactions, however, transactions are never guaranteed to make progress. Fixes: 70fe3d9 ("powerpc: Restore FPU/VEC/VSX if previously used") Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:08 +08:00
if (cpu_has_feature(CPU_FTR_ALTIVEC) && msr_diff & MSR_VEC)
current->thread.load_vec = 1;
#endif
powerpc: Restore FPU/VEC/VSX if previously used Currently the FPU, VEC and VSX facilities are lazily loaded. This is not a problem unless a process is using these facilities. Modern versions of GCC are very good at automatically vectorising code, new and modernised workloads make use of floating point and vector facilities, even the kernel makes use of vectorised memcpy. All this combined greatly increases the cost of a syscall since the kernel uses the facilities sometimes even in syscall fast-path making it increasingly common for a thread to take an *_unavailable exception soon after a syscall, not to mention potentially taking all three. The obvious overcompensation to this problem is to simply always load all the facilities on every exit to userspace. Loading up all FPU, VEC and VSX registers every time can be expensive and if a workload does avoid using them, it should not be forced to incur this penalty. An 8bit counter is used to detect if the registers have been used in the past and the registers are always loaded until the value wraps to back to zero. Several versions of the assembly in entry_64.S were tested: 1. Always calling C. 2. Performing a common case check and then calling C. 3. A complex check in asm. After some benchmarking it was determined that avoiding C in the common case is a performance benefit (option 2). The full check in asm (option 3) greatly complicated that codepath for a negligible performance gain and the trade-off was deemed not worth it. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> [mpe: Move load_vec in the struct to fill an existing hole, reword change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> fixup
2016-02-29 14:53:47 +08:00
restore_math(regs);
powerpc: Don't corrupt transactional state when using FP/VMX in kernel Currently, when we have a process using the transactional memory facilities on POWER8 (that is, the processor is in transactional or suspended state), and the process enters the kernel and the kernel then uses the floating-point or vector (VMX/Altivec) facility, we end up corrupting the user-visible FP/VMX/VSX state. This happens, for example, if a page fault causes a copy-on-write operation, because the copy_page function will use VMX to do the copy on POWER8. The test program below demonstrates the bug. The bug happens because when FP/VMX state for a transactional process is stored in the thread_struct, we store the checkpointed state in .fp_state/.vr_state and the transactional (current) state in .transact_fp/.transact_vr. However, when the kernel wants to use FP/VMX, it calls enable_kernel_fp() or enable_kernel_altivec(), which saves the current state in .fp_state/.vr_state. Furthermore, when we return to the user process we return with FP/VMX/VSX disabled. The next time the process uses FP/VMX/VSX, we don't know which set of state (the current register values, .fp_state/.vr_state, or .transact_fp/.transact_vr) we should be using, since we have no way to tell if we are still in the same transaction, and if not, whether the previous transaction succeeded or failed. Thus it is necessary to strictly adhere to the rule that if FP has been enabled at any point in a transaction, we must keep FP enabled for the user process with the current transactional state in the FP registers, until we detect that it is no longer in a transaction. Similarly for VMX; once enabled it must stay enabled until the process is no longer transactional. In order to keep this rule, we add a new thread_info flag which we test when returning from the kernel to userspace, called TIF_RESTORE_TM. This flag indicates that there is FP/VMX/VSX state to be restored before entering userspace, and when it is set the .tm_orig_msr field in the thread_struct indicates what state needs to be restored. The restoration is done by restore_tm_state(). The TIF_RESTORE_TM bit is set by new giveup_fpu/altivec_maybe_transactional helpers, which are called from enable_kernel_fp/altivec, giveup_vsx, and flush_fp/altivec_to_thread instead of giveup_fpu/altivec. The other thing to be done is to get the transactional FP/VMX/VSX state from .fp_state/.vr_state when doing reclaim, if that state has been saved there by giveup_fpu/altivec_maybe_transactional. Having done this, we set the FP/VMX bit in the thread's MSR after reclaim to indicate that that part of the state is now valid (having been reclaimed from the processor's checkpointed state). Finally, in the signal handling code, we move the clearing of the transactional state bits in the thread's MSR a bit earlier, before calling flush_fp_to_thread(), so that we don't unnecessarily set the TIF_RESTORE_TM bit. This is the test program: /* Michael Neuling 4/12/2013 * * See if the altivec state is leaked out of an aborted transaction due to * kernel vmx copy loops. * * gcc -m64 htm_vmxcopy.c -o htm_vmxcopy * */ /* We don't use all of these, but for reference: */ int main(int argc, char *argv[]) { long double vecin = 1.3; long double vecout; unsigned long pgsize = getpagesize(); int i; int fd; int size = pgsize*16; char tmpfile[] = "/tmp/page_faultXXXXXX"; char buf[pgsize]; char *a; uint64_t aborted = 0; fd = mkstemp(tmpfile); assert(fd >= 0); memset(buf, 0, pgsize); for (i = 0; i < size; i += pgsize) assert(write(fd, buf, pgsize) == pgsize); unlink(tmpfile); a = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); assert(a != MAP_FAILED); asm __volatile__( "lxvd2x 40,0,%[vecinptr] ; " // set 40 to initial value TBEGIN "beq 3f ;" TSUSPEND "xxlxor 40,40,40 ; " // set 40 to 0 "std 5, 0(%[map]) ;" // cause kernel vmx copy page TABORT TRESUME TEND "li %[res], 0 ;" "b 5f ;" "3: ;" // Abort handler "li %[res], 1 ;" "5: ;" "stxvd2x 40,0,%[vecoutptr] ; " : [res]"=r"(aborted) : [vecinptr]"r"(&vecin), [vecoutptr]"r"(&vecout), [map]"r"(a) : "memory", "r0", "r3", "r4", "r5", "r6", "r7"); if (aborted && (vecin != vecout)){ printf("FAILED: vector state leaked on abort %f != %f\n", (double)vecin, (double)vecout); exit(1); } munmap(a, size); close(fd); printf("PASSED!\n"); return 0; } Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-13 12:56:29 +08:00
regs->msr |= msr_diff;
}
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes When we switch out a task, we need to save both the checkpointed and the speculated state into the thread struct. Similarly when we are switching in a task we need to load both the checkpointed and speculated state. If the task was using FP, we non-lazily reload both the original and the speculative FP register states. This is because the kernel doesn't see if/when a TM rollback occurs, so if we take an FP unavoidable later, we are unable to determine which set of FP regs need to be restored. This simply adds these functions. It doesn't hook them into the existing code yet. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:37 +08:00
#else
#define tm_recheckpoint_new_task(new)
powerpc: tm: Always use fp_state and vr_state to store live registers There is currently an inconsistency as to how the entire CPU register state is saved and restored when a thread uses transactional memory (TM). Using transactional memory results in the CPU having duplicated (almost) all of its register state. This duplication results in a set of registers which can be considered 'live', those being currently modified by the instructions being executed and another set that is frozen at a point in time. On context switch, both sets of state have to be saved and (later) restored. These two states are often called a variety of different things. Common terms for the state which only exists after the CPU has entered a transaction (performed a TBEGIN instruction) in hardware are 'transactional' or 'speculative'. Between a TBEGIN and a TEND or TABORT (or an event that causes the hardware to abort), regardless of the use of TSUSPEND the transactional state can be referred to as the live state. The second state is often to referred to as the 'checkpointed' state and is a duplication of the live state when the TBEGIN instruction is executed. This state is kept in the hardware and will be rolled back to on transaction failure. Currently all the registers stored in pt_regs are ALWAYS the live registers, that is, when a thread has transactional registers their values are stored in pt_regs and the checkpointed state is in ckpt_regs. A strange opposite is true for fp_state/vr_state. When a thread is non transactional fp_state/vr_state holds the live registers. When a thread has initiated a transaction fp_state/vr_state holds the checkpointed state and transact_fp/transact_vr become the structure which holds the live state (at this point it is a transactional state). This method creates confusion as to where the live state is, in some circumstances it requires extra work to determine where to put the live state and prevents the use of common functions designed (probably before TM) to save the live state. With this patch pt_regs, fp_state and vr_state all represent the same thing and the other structures [pending rename] are for checkpointed state. Acked-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:24 +08:00
#define __switch_to_tm(prev, new)
powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes When we switch out a task, we need to save both the checkpointed and the speculated state into the thread struct. Similarly when we are switching in a task we need to load both the checkpointed and speculated state. If the task was using FP, we non-lazily reload both the original and the speculative FP register states. This is because the kernel doesn't see if/when a TM rollback occurs, so if we take an FP unavoidable later, we are unable to determine which set of FP regs need to be restored. This simply adds these functions. It doesn't hook them into the existing code yet. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:37 +08:00
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers This is a rewrite so that we don't assume we are using the DABR throughout the code. We now use the arch_hw_breakpoint to store the breakpoint in a generic manner in the thread_struct, rather than storing the raw DABR value. The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from userspace. We keep this functionality, so that future changes (like the POWER8 DAWR), will still fake the DABR to userspace. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-20 22:06:44 +08:00
powerpc: Create context switch helpers save_sprs() and restore_sprs() Move all our context switch SPR save and restore code into two helpers. We do a few optimisations: - Group all mfsprs and all mtsprs. In many cases an mtspr sets a scoreboarding bit that an mfspr waits on, so the current practise of mfspr A; mtspr A; mfpsr B; mtspr B is the worst scheduling we can do. - SPR writes are slow, so check that the value is changing before writing it. A context switch microbenchmark using yield(): http://ozlabs.org/~anton/junkcode/context_switch2.c ./context_switch2 --test=yield 0 0 shows an improvement of almost 10% on POWER8. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:43:55 +08:00
static inline void save_sprs(struct thread_struct *t)
{
#ifdef CONFIG_ALTIVEC
powerpc/process: Fix altivec SPR not being saved In save_sprs() in process.c contains the following test: if (cpu_has_feature(cpu_has_feature(CPU_FTR_ALTIVEC))) t->vrsave = mfspr(SPRN_VRSAVE); CPU feature with the mask 0x1 is CPU_FTR_COHERENT_ICACHE so the test is equivilent to: if (cpu_has_feature(CPU_FTR_ALTIVEC) && cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) On CPUs without support for both (i.e G5) this results in vrsave not being saved between context switches. The vector register save/restore code doesn't use VRSAVE to determine which registers to save/restore, but the value of VRSAVE is used to determine if altivec is being used in several code paths. Fixes: 152d523e6307 ("powerpc: Create context switch helpers save_sprs() and restore_sprs()") Cc: stable@vger.kernel.org Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-08 06:08:47 +08:00
if (cpu_has_feature(CPU_FTR_ALTIVEC))
powerpc: Create context switch helpers save_sprs() and restore_sprs() Move all our context switch SPR save and restore code into two helpers. We do a few optimisations: - Group all mfsprs and all mtsprs. In many cases an mtspr sets a scoreboarding bit that an mfspr waits on, so the current practise of mfspr A; mtspr A; mfpsr B; mtspr B is the worst scheduling we can do. - SPR writes are slow, so check that the value is changing before writing it. A context switch microbenchmark using yield(): http://ozlabs.org/~anton/junkcode/context_switch2.c ./context_switch2 --test=yield 0 0 shows an improvement of almost 10% on POWER8. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:43:55 +08:00
t->vrsave = mfspr(SPRN_VRSAVE);
#endif
#ifdef CONFIG_PPC_BOOK3S_64
if (cpu_has_feature(CPU_FTR_DSCR))
t->dscr = mfspr(SPRN_DSCR);
if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
t->bescr = mfspr(SPRN_BESCR);
t->ebbhr = mfspr(SPRN_EBBHR);
t->ebbrr = mfspr(SPRN_EBBRR);
t->fscr = mfspr(SPRN_FSCR);
/*
* Note that the TAR is not available for use in the kernel.
* (To provide this, the TAR should be backed up/restored on
* exception entry/exit instead, and be in pt_regs. FIXME,
* this should be in pt_regs anyway (for debug).)
*/
t->tar = mfspr(SPRN_TAR);
}
#endif
}
static inline void restore_sprs(struct thread_struct *old_thread,
struct thread_struct *new_thread)
{
#ifdef CONFIG_ALTIVEC
if (cpu_has_feature(CPU_FTR_ALTIVEC) &&
old_thread->vrsave != new_thread->vrsave)
mtspr(SPRN_VRSAVE, new_thread->vrsave);
#endif
#ifdef CONFIG_PPC_BOOK3S_64
if (cpu_has_feature(CPU_FTR_DSCR)) {
u64 dscr = get_paca()->dscr_default;
powerpc: Improve FSCR init and context switching This fixes a few issues with FSCR init and switching. In commit 152d523e6307 ("powerpc: Create context switch helpers save_sprs() and restore_sprs()") we moved the setting of the FSCR register from inside an CPU_FTR_ARCH_207S section to inside just a CPU_FTR_ARCH_DSCR section. Hence we are setting FSCR on POWER6/7 where the FSCR doesn't exist. This is harmless but we shouldn't do it. Also, we can simplify the FSCR context switch. We don't need to go through the calculation involving dscr_inherit. We can just restore what we saved last time. We also set an initial value in INIT_THREAD, so that pid 1 which is cloned from that gets a sane value. Based on patch by Jack Miller. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-06-09 10:31:08 +08:00
if (new_thread->dscr_inherit)
powerpc: Create context switch helpers save_sprs() and restore_sprs() Move all our context switch SPR save and restore code into two helpers. We do a few optimisations: - Group all mfsprs and all mtsprs. In many cases an mtspr sets a scoreboarding bit that an mfspr waits on, so the current practise of mfspr A; mtspr A; mfpsr B; mtspr B is the worst scheduling we can do. - SPR writes are slow, so check that the value is changing before writing it. A context switch microbenchmark using yield(): http://ozlabs.org/~anton/junkcode/context_switch2.c ./context_switch2 --test=yield 0 0 shows an improvement of almost 10% on POWER8. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:43:55 +08:00
dscr = new_thread->dscr;
if (old_thread->dscr != dscr)
mtspr(SPRN_DSCR, dscr);
}
if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
if (old_thread->bescr != new_thread->bescr)
mtspr(SPRN_BESCR, new_thread->bescr);
if (old_thread->ebbhr != new_thread->ebbhr)
mtspr(SPRN_EBBHR, new_thread->ebbhr);
if (old_thread->ebbrr != new_thread->ebbrr)
mtspr(SPRN_EBBRR, new_thread->ebbrr);
powerpc: Improve FSCR init and context switching This fixes a few issues with FSCR init and switching. In commit 152d523e6307 ("powerpc: Create context switch helpers save_sprs() and restore_sprs()") we moved the setting of the FSCR register from inside an CPU_FTR_ARCH_207S section to inside just a CPU_FTR_ARCH_DSCR section. Hence we are setting FSCR on POWER6/7 where the FSCR doesn't exist. This is harmless but we shouldn't do it. Also, we can simplify the FSCR context switch. We don't need to go through the calculation involving dscr_inherit. We can just restore what we saved last time. We also set an initial value in INIT_THREAD, so that pid 1 which is cloned from that gets a sane value. Based on patch by Jack Miller. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-06-09 10:31:08 +08:00
if (old_thread->fscr != new_thread->fscr)
mtspr(SPRN_FSCR, new_thread->fscr);
powerpc: Create context switch helpers save_sprs() and restore_sprs() Move all our context switch SPR save and restore code into two helpers. We do a few optimisations: - Group all mfsprs and all mtsprs. In many cases an mtspr sets a scoreboarding bit that an mfspr waits on, so the current practise of mfspr A; mtspr A; mfpsr B; mtspr B is the worst scheduling we can do. - SPR writes are slow, so check that the value is changing before writing it. A context switch microbenchmark using yield(): http://ozlabs.org/~anton/junkcode/context_switch2.c ./context_switch2 --test=yield 0 0 shows an improvement of almost 10% on POWER8. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:43:55 +08:00
if (old_thread->tar != new_thread->tar)
mtspr(SPRN_TAR, new_thread->tar);
}
#endif
}
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
struct task_struct *__switch_to(struct task_struct *prev,
struct task_struct *new)
{
struct thread_struct *new_thread, *old_thread;
struct task_struct *last;
powerpc: mmu_gather rework Fix up powerpc to the new mmu_gather stuff. PPC has an extra batching queue to RCU free the actual pagetable allocations, use the ARCH extentions for that for now. For the ppc64_tlb_batch, which tracks the vaddrs to unhash from the hardware hash-table, keep using per-cpu arrays but flush on context switch and use a TLF bit to track the lazy_mmu state. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Tony Luck <tony.luck@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:11:48 +08:00
#ifdef CONFIG_PPC_BOOK3S_64
struct ppc64_tlb_batch *batch;
#endif
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
powerpc: Create context switch helpers save_sprs() and restore_sprs() Move all our context switch SPR save and restore code into two helpers. We do a few optimisations: - Group all mfsprs and all mtsprs. In many cases an mtspr sets a scoreboarding bit that an mfspr waits on, so the current practise of mfspr A; mtspr A; mfpsr B; mtspr B is the worst scheduling we can do. - SPR writes are slow, so check that the value is changing before writing it. A context switch microbenchmark using yield(): http://ozlabs.org/~anton/junkcode/context_switch2.c ./context_switch2 --test=yield 0 0 shows an improvement of almost 10% on POWER8. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:43:55 +08:00
new_thread = &new->thread;
old_thread = &current->thread;
powerpc/tm: Remove interrupt disable in __switch_to() We currently turn IRQs off in __switch_to(0 but this is unnecessary as it's already disabled in the caller. This removes the IRQ disable but adds a check to make sure it is really off in case this changes in future. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-02 15:15:14 +08:00
WARN_ON(!irqs_disabled());
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
#ifdef CONFIG_PPC64
/*
* Collect processor utilization data per process
*/
if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
powerpc: Replace __get_cpu_var uses This still has not been merged and now powerpc is the only arch that does not have this change. Sorry about missing linuxppc-dev before. V2->V2 - Fix up to work against 3.18-rc1 __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> Signed-off-by: Christoph Lameter <cl@linux.com> [mpe: Fix build errors caused by set/or_softirq_pending(), and rework assignment in __set_breakpoint() to use memcpy().] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-22 04:23:25 +08:00
struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array);
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
long unsigned start_tb, current_tb;
start_tb = old_thread->start_tb;
cu->current_tb = current_tb = mfspr(SPRN_PURR);
old_thread->accum_tb += (current_tb - start_tb);
new_thread->start_tb = current_tb;
}
powerpc: mmu_gather rework Fix up powerpc to the new mmu_gather stuff. PPC has an extra batching queue to RCU free the actual pagetable allocations, use the ARCH extentions for that for now. For the ppc64_tlb_batch, which tracks the vaddrs to unhash from the hardware hash-table, keep using per-cpu arrays but flush on context switch and use a TLF bit to track the lazy_mmu state. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Tony Luck <tony.luck@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:11:48 +08:00
#endif /* CONFIG_PPC64 */
powerpc/mm/radix: Use STD_MMU_64 to properly isolate hash related code We also use MMU_FTR_RADIX to branch out from code path specific to hash. No functionality change. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 21:26:07 +08:00
#ifdef CONFIG_PPC_STD_MMU_64
powerpc: Replace __get_cpu_var uses This still has not been merged and now powerpc is the only arch that does not have this change. Sorry about missing linuxppc-dev before. V2->V2 - Fix up to work against 3.18-rc1 __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> Signed-off-by: Christoph Lameter <cl@linux.com> [mpe: Fix build errors caused by set/or_softirq_pending(), and rework assignment in __set_breakpoint() to use memcpy().] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-22 04:23:25 +08:00
batch = this_cpu_ptr(&ppc64_tlb_batch);
powerpc: mmu_gather rework Fix up powerpc to the new mmu_gather stuff. PPC has an extra batching queue to RCU free the actual pagetable allocations, use the ARCH extentions for that for now. For the ppc64_tlb_batch, which tracks the vaddrs to unhash from the hardware hash-table, keep using per-cpu arrays but flush on context switch and use a TLF bit to track the lazy_mmu state. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Tony Luck <tony.luck@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:11:48 +08:00
if (batch->active) {
current_thread_info()->local_flags |= _TLF_LAZY_MMU;
if (batch->index)
__flush_tlb_pending(batch);
batch->active = 0;
}
powerpc/mm/radix: Use STD_MMU_64 to properly isolate hash related code We also use MMU_FTR_RADIX to branch out from code path specific to hash. No functionality change. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 21:26:07 +08:00
#endif /* CONFIG_PPC_STD_MMU_64 */
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
powerpc: Rearrange __switch_to() Most of __switch_to() is housekeeping, TLB batching, timekeeping etc. Move these away from the more complex and critical context switching code. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:10 +08:00
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
switch_booke_debug_regs(&new->thread.debug);
#else
/*
* For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would
* schedule DABR
*/
#ifndef CONFIG_HAVE_HW_BREAKPOINT
if (unlikely(!hw_brk_match(this_cpu_ptr(&current_brk), &new->thread.hw_brk)))
__set_breakpoint(&new->thread.hw_brk);
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#endif
/*
* We need to save SPRs before treclaim/trecheckpoint as these will
* change a number of them.
*/
save_sprs(&prev->thread);
/* Save FPU, Altivec, VSX and SPE state */
giveup_all(prev);
powerpc: tm: Always use fp_state and vr_state to store live registers There is currently an inconsistency as to how the entire CPU register state is saved and restored when a thread uses transactional memory (TM). Using transactional memory results in the CPU having duplicated (almost) all of its register state. This duplication results in a set of registers which can be considered 'live', those being currently modified by the instructions being executed and another set that is frozen at a point in time. On context switch, both sets of state have to be saved and (later) restored. These two states are often called a variety of different things. Common terms for the state which only exists after the CPU has entered a transaction (performed a TBEGIN instruction) in hardware are 'transactional' or 'speculative'. Between a TBEGIN and a TEND or TABORT (or an event that causes the hardware to abort), regardless of the use of TSUSPEND the transactional state can be referred to as the live state. The second state is often to referred to as the 'checkpointed' state and is a duplication of the live state when the TBEGIN instruction is executed. This state is kept in the hardware and will be rolled back to on transaction failure. Currently all the registers stored in pt_regs are ALWAYS the live registers, that is, when a thread has transactional registers their values are stored in pt_regs and the checkpointed state is in ckpt_regs. A strange opposite is true for fp_state/vr_state. When a thread is non transactional fp_state/vr_state holds the live registers. When a thread has initiated a transaction fp_state/vr_state holds the checkpointed state and transact_fp/transact_vr become the structure which holds the live state (at this point it is a transactional state). This method creates confusion as to where the live state is, in some circumstances it requires extra work to determine where to put the live state and prevents the use of common functions designed (probably before TM) to save the live state. With this patch pt_regs, fp_state and vr_state all represent the same thing and the other structures [pending rename] are for checkpointed state. Acked-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:24 +08:00
__switch_to_tm(prev, new);
[POWERPC] Fix PMU + soft interrupt disable bug Since the PMU is an NMI now, it can come at any time we are only soft disabled. We must hard disable around the two places we allow the kernel stack SLB and r1 to go out of sync. Otherwise the PMU exception can force a kernel stack SLB into another slot, which can lead to it getting evicted, which can lead to a nasty unrecoverable SLB miss in the exception entry code. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-03-17 12:27:09 +08:00
/*
* We can't take a PMU exception inside _switch() since there is a
* window where the kernel stack SLB and the kernel stack are out
* of sync. Hard disable here.
*/
hard_irq_disable();
powerpc: Hook in new transactional memory code This hooks the new transactional memory code into context switching, FP/VMX/VMX unavailable and exception return. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:40 +08:00
powerpc: Call restore_sprs() before _switch() commit 152d523e6307 ("powerpc: Create context switch helpers save_sprs() and restore_sprs()") moved the restore of SPRs after the call to _switch(). There is an issue with this approach - new tasks do not return through _switch(), they are set up by copy_thread() to directly return through ret_from_fork() or ret_from_kernel_thread(). This means restore_sprs() is not getting called for new tasks. Fix this by moving restore_sprs() before _switch(). Fixes: 152d523e6307 ("powerpc: Create context switch helpers save_sprs() and restore_sprs()") Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-10 17:44:39 +08:00
/*
* Call restore_sprs() before calling _switch(). If we move it after
* _switch() then we miss out on calling it for new tasks. The reason
* for this is we manually create a stack frame for new tasks that
* directly returns through ret_from_fork() or
* ret_from_kernel_thread(). See copy_thread() for details.
*/
powerpc: Rearrange __switch_to() Most of __switch_to() is housekeeping, TLB batching, timekeeping etc. Move these away from the more complex and critical context switching code. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:10 +08:00
restore_sprs(old_thread, new_thread);
powerpc: Call restore_sprs() before _switch() commit 152d523e6307 ("powerpc: Create context switch helpers save_sprs() and restore_sprs()") moved the restore of SPRs after the call to _switch(). There is an issue with this approach - new tasks do not return through _switch(), they are set up by copy_thread() to directly return through ret_from_fork() or ret_from_kernel_thread(). This means restore_sprs() is not getting called for new tasks. Fix this by moving restore_sprs() before _switch(). Fixes: 152d523e6307 ("powerpc: Create context switch helpers save_sprs() and restore_sprs()") Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-10 17:44:39 +08:00
last = _switch(old_thread, new_thread);
powerpc/mm/radix: Use STD_MMU_64 to properly isolate hash related code We also use MMU_FTR_RADIX to branch out from code path specific to hash. No functionality change. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 21:26:07 +08:00
#ifdef CONFIG_PPC_STD_MMU_64
powerpc: mmu_gather rework Fix up powerpc to the new mmu_gather stuff. PPC has an extra batching queue to RCU free the actual pagetable allocations, use the ARCH extentions for that for now. For the ppc64_tlb_batch, which tracks the vaddrs to unhash from the hardware hash-table, keep using per-cpu arrays but flush on context switch and use a TLF bit to track the lazy_mmu state. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Tony Luck <tony.luck@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:11:48 +08:00
if (current_thread_info()->local_flags & _TLF_LAZY_MMU) {
current_thread_info()->local_flags &= ~_TLF_LAZY_MMU;
powerpc: Replace __get_cpu_var uses This still has not been merged and now powerpc is the only arch that does not have this change. Sorry about missing linuxppc-dev before. V2->V2 - Fix up to work against 3.18-rc1 __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> Signed-off-by: Christoph Lameter <cl@linux.com> [mpe: Fix build errors caused by set/or_softirq_pending(), and rework assignment in __set_breakpoint() to use memcpy().] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-22 04:23:25 +08:00
batch = this_cpu_ptr(&ppc64_tlb_batch);
powerpc: mmu_gather rework Fix up powerpc to the new mmu_gather stuff. PPC has an extra batching queue to RCU free the actual pagetable allocations, use the ARCH extentions for that for now. For the ppc64_tlb_batch, which tracks the vaddrs to unhash from the hardware hash-table, keep using per-cpu arrays but flush on context switch and use a TLF bit to track the lazy_mmu state. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Tony Luck <tony.luck@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:11:48 +08:00
batch->active = 1;
}
powerpc: Restore FPU/VEC/VSX if previously used Currently the FPU, VEC and VSX facilities are lazily loaded. This is not a problem unless a process is using these facilities. Modern versions of GCC are very good at automatically vectorising code, new and modernised workloads make use of floating point and vector facilities, even the kernel makes use of vectorised memcpy. All this combined greatly increases the cost of a syscall since the kernel uses the facilities sometimes even in syscall fast-path making it increasingly common for a thread to take an *_unavailable exception soon after a syscall, not to mention potentially taking all three. The obvious overcompensation to this problem is to simply always load all the facilities on every exit to userspace. Loading up all FPU, VEC and VSX registers every time can be expensive and if a workload does avoid using them, it should not be forced to incur this penalty. An 8bit counter is used to detect if the registers have been used in the past and the registers are always loaded until the value wraps to back to zero. Several versions of the assembly in entry_64.S were tested: 1. Always calling C. 2. Performing a common case check and then calling C. 3. A complex check in asm. After some benchmarking it was determined that avoiding C in the common case is a performance benefit (option 2). The full check in asm (option 3) greatly complicated that codepath for a negligible performance gain and the trade-off was deemed not worth it. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> [mpe: Move load_vec in the struct to fill an existing hole, reword change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> fixup
2016-02-29 14:53:47 +08:00
if (current_thread_info()->task->thread.regs)
restore_math(current_thread_info()->task->thread.regs);
powerpc/mm/radix: Use STD_MMU_64 to properly isolate hash related code We also use MMU_FTR_RADIX to branch out from code path specific to hash. No functionality change. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 21:26:07 +08:00
#endif /* CONFIG_PPC_STD_MMU_64 */
powerpc: mmu_gather rework Fix up powerpc to the new mmu_gather stuff. PPC has an extra batching queue to RCU free the actual pagetable allocations, use the ARCH extentions for that for now. For the ppc64_tlb_batch, which tracks the vaddrs to unhash from the hardware hash-table, keep using per-cpu arrays but flush on context switch and use a TLF bit to track the lazy_mmu state. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Tony Luck <tony.luck@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:11:48 +08:00
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
return last;
}
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
static int instructions_to_print = 16;
static void show_instructions(struct pt_regs *regs)
{
int i;
unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
sizeof(int));
printk("Instruction dump:");
for (i = 0; i < instructions_to_print; i++) {
int instr;
if (!(i % 8))
powerpc/oops: Fix missing pr_cont()s in instruction dump Since the KERN_CONT changes, the current code in show_instructions() prints out a whole bunch of unnecessary newlines. Change occurrences of printk("\n") to pr_cont("\n"). While we're here, change all the other cases of printk(KERN_CONT ...) to pr_cont() as well. Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-04 14:20:40 +08:00
pr_cont("\n");
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
[POWERPC] Make instruction dumping work in real mode On non-book-E, exceptions execute in real mode. If a fault happens that leads to a register dump, the kernel currently prints XXXXXXXX because it doesn't realize that PC is a physical address. This patch checks whether instruction address translation is turned on, and if not converts PC into a virtual address. Signed-off-by: Scott Wood <scottwood@freescale.com> Acked-by: Kumar Gala <galak@kernel.crashing.org> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-09-28 02:38:55 +08:00
#if !defined(CONFIG_BOOKE)
/* If executing with the IMMU off, adjust pc rather
* than print XXXXXXXX.
*/
if (!(regs->msr & MSR_IR))
pc = (unsigned long)phys_to_virt(pc);
#endif
[POWERPC] Better check in show_instructions Instead of just checking that an address is in the right range, use the provided __kernel_text_address() helper which covers both the kernel and module text sections. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-10-13 10:17:16 +08:00
if (!__kernel_text_address(pc) ||
powerpc: Use probe_kernel_address in show_instructions We really don't want to take a pagefault in show_instructions, so use probe_kernel_address instead of __get_user. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-13 17:27:15 +08:00
probe_kernel_address((unsigned int __user *)pc, instr)) {
powerpc/oops: Fix missing pr_cont()s in instruction dump Since the KERN_CONT changes, the current code in show_instructions() prints out a whole bunch of unnecessary newlines. Change occurrences of printk("\n") to pr_cont("\n"). While we're here, change all the other cases of printk(KERN_CONT ...) to pr_cont() as well. Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-04 14:20:40 +08:00
pr_cont("XXXXXXXX ");
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
} else {
if (regs->nip == pc)
powerpc/oops: Fix missing pr_cont()s in instruction dump Since the KERN_CONT changes, the current code in show_instructions() prints out a whole bunch of unnecessary newlines. Change occurrences of printk("\n") to pr_cont("\n"). While we're here, change all the other cases of printk(KERN_CONT ...) to pr_cont() as well. Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-04 14:20:40 +08:00
pr_cont("<%08x> ", instr);
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
else
powerpc/oops: Fix missing pr_cont()s in instruction dump Since the KERN_CONT changes, the current code in show_instructions() prints out a whole bunch of unnecessary newlines. Change occurrences of printk("\n") to pr_cont("\n"). While we're here, change all the other cases of printk(KERN_CONT ...) to pr_cont() as well. Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-04 14:20:40 +08:00
pr_cont("%08x ", instr);
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
}
pc += sizeof(int);
}
powerpc/oops: Fix missing pr_cont()s in instruction dump Since the KERN_CONT changes, the current code in show_instructions() prints out a whole bunch of unnecessary newlines. Change occurrences of printk("\n") to pr_cont("\n"). While we're here, change all the other cases of printk(KERN_CONT ...) to pr_cont() as well. Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-04 14:20:40 +08:00
pr_cont("\n");
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
}
powerpc: Print MSR TM bits in oops messages Print MSR TM bits in oops messages. This appends them to the end like this: MSR: 8000000502823031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[TE]> You get the TM[] only if at least one TM MSR bit is set. Inside the TM[], E means Enabled (bit 32), S means Suspended (bit 33), and T means Transactional (bit 34) If no bits are set, you get no TM[] output. Include rework of printbits() to handle this case. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-11-20 12:15:32 +08:00
struct regbit {
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
unsigned long bit;
const char *name;
powerpc: Print MSR TM bits in oops messages Print MSR TM bits in oops messages. This appends them to the end like this: MSR: 8000000502823031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[TE]> You get the TM[] only if at least one TM MSR bit is set. Inside the TM[], E means Enabled (bit 32), S means Suspended (bit 33), and T means Transactional (bit 34) If no bits are set, you get no TM[] output. Include rework of printbits() to handle this case. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-11-20 12:15:32 +08:00
};
static struct regbit msr_bits[] = {
powerpc: Decode correct MSR bits in oops output On a 64bit book3s machine I have an oops from a system reset that claims the book3e CE bit was set: MSR: 8000000000021032 <ME,CE,IR,DR> CR: 24004082 XER: 00000010 On a book3s machine system reset sets IBM bit 46 and 47 depending on the power saving mode. Separate the definitions by type and for completeness add the rest of the bits in. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 03:35:57 +08:00
#if defined(CONFIG_PPC64) && !defined(CONFIG_BOOKE)
{MSR_SF, "SF"},
{MSR_HV, "HV"},
#endif
{MSR_VEC, "VEC"},
{MSR_VSX, "VSX"},
#ifdef CONFIG_BOOKE
{MSR_CE, "CE"},
#endif
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
{MSR_EE, "EE"},
{MSR_PR, "PR"},
{MSR_FP, "FP"},
{MSR_ME, "ME"},
powerpc: Decode correct MSR bits in oops output On a 64bit book3s machine I have an oops from a system reset that claims the book3e CE bit was set: MSR: 8000000000021032 <ME,CE,IR,DR> CR: 24004082 XER: 00000010 On a book3s machine system reset sets IBM bit 46 and 47 depending on the power saving mode. Separate the definitions by type and for completeness add the rest of the bits in. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 03:35:57 +08:00
#ifdef CONFIG_BOOKE
powerpc: Add MSR[CE, DE] to the MSR bits we print on show_regs() Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-11-19 12:39:53 +08:00
{MSR_DE, "DE"},
powerpc: Decode correct MSR bits in oops output On a 64bit book3s machine I have an oops from a system reset that claims the book3e CE bit was set: MSR: 8000000000021032 <ME,CE,IR,DR> CR: 24004082 XER: 00000010 On a book3s machine system reset sets IBM bit 46 and 47 depending on the power saving mode. Separate the definitions by type and for completeness add the rest of the bits in. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 03:35:57 +08:00
#else
{MSR_SE, "SE"},
{MSR_BE, "BE"},
#endif
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
{MSR_IR, "IR"},
{MSR_DR, "DR"},
powerpc: Decode correct MSR bits in oops output On a 64bit book3s machine I have an oops from a system reset that claims the book3e CE bit was set: MSR: 8000000000021032 <ME,CE,IR,DR> CR: 24004082 XER: 00000010 On a book3s machine system reset sets IBM bit 46 and 47 depending on the power saving mode. Separate the definitions by type and for completeness add the rest of the bits in. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25 03:35:57 +08:00
{MSR_PMM, "PMM"},
#ifndef CONFIG_BOOKE
{MSR_RI, "RI"},
{MSR_LE, "LE"},
#endif
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
{0, NULL}
};
powerpc: Print MSR TM bits in oops messages Print MSR TM bits in oops messages. This appends them to the end like this: MSR: 8000000502823031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[TE]> You get the TM[] only if at least one TM MSR bit is set. Inside the TM[], E means Enabled (bit 32), S means Suspended (bit 33), and T means Transactional (bit 34) If no bits are set, you get no TM[] output. Include rework of printbits() to handle this case. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-11-20 12:15:32 +08:00
static void print_bits(unsigned long val, struct regbit *bits, const char *sep)
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
{
powerpc: Print MSR TM bits in oops messages Print MSR TM bits in oops messages. This appends them to the end like this: MSR: 8000000502823031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[TE]> You get the TM[] only if at least one TM MSR bit is set. Inside the TM[], E means Enabled (bit 32), S means Suspended (bit 33), and T means Transactional (bit 34) If no bits are set, you get no TM[] output. Include rework of printbits() to handle this case. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-11-20 12:15:32 +08:00
const char *s = "";
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
for (; bits->bit; ++bits)
if (val & bits->bit) {
powerpc/oops: Fix missing pr_cont()s in print_msr_bits() et. al. Since the KERN_CONT changes these are being horribly split across lines, for example: MSR: 8000000000009033 < SF,EE ,ME,IR ,DR,RI ,LE> So fix it by using pr_cont() where appropriate. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-02 19:20:47 +08:00
pr_cont("%s%s", s, bits->name);
powerpc: Print MSR TM bits in oops messages Print MSR TM bits in oops messages. This appends them to the end like this: MSR: 8000000502823031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[TE]> You get the TM[] only if at least one TM MSR bit is set. Inside the TM[], E means Enabled (bit 32), S means Suspended (bit 33), and T means Transactional (bit 34) If no bits are set, you get no TM[] output. Include rework of printbits() to handle this case. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-11-20 12:15:32 +08:00
s = sep;
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
}
powerpc: Print MSR TM bits in oops messages Print MSR TM bits in oops messages. This appends them to the end like this: MSR: 8000000502823031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[TE]> You get the TM[] only if at least one TM MSR bit is set. Inside the TM[], E means Enabled (bit 32), S means Suspended (bit 33), and T means Transactional (bit 34) If no bits are set, you get no TM[] output. Include rework of printbits() to handle this case. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-11-20 12:15:32 +08:00
}
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
static struct regbit msr_tm_bits[] = {
{MSR_TS_T, "T"},
{MSR_TS_S, "S"},
{MSR_TM, "E"},
{0, NULL}
};
static void print_tm_bits(unsigned long val)
{
/*
* This only prints something if at least one of the TM bit is set.
* Inside the TM[], the output means:
* E: Enabled (bit 32)
* S: Suspended (bit 33)
* T: Transactional (bit 34)
*/
if (val & (MSR_TM | MSR_TS_S | MSR_TS_T)) {
powerpc/oops: Fix missing pr_cont()s in print_msr_bits() et. al. Since the KERN_CONT changes these are being horribly split across lines, for example: MSR: 8000000000009033 < SF,EE ,ME,IR ,DR,RI ,LE> So fix it by using pr_cont() where appropriate. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-02 19:20:47 +08:00
pr_cont(",TM[");
powerpc: Print MSR TM bits in oops messages Print MSR TM bits in oops messages. This appends them to the end like this: MSR: 8000000502823031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[TE]> You get the TM[] only if at least one TM MSR bit is set. Inside the TM[], E means Enabled (bit 32), S means Suspended (bit 33), and T means Transactional (bit 34) If no bits are set, you get no TM[] output. Include rework of printbits() to handle this case. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-11-20 12:15:32 +08:00
print_bits(val, msr_tm_bits, "");
powerpc/oops: Fix missing pr_cont()s in print_msr_bits() et. al. Since the KERN_CONT changes these are being horribly split across lines, for example: MSR: 8000000000009033 < SF,EE ,ME,IR ,DR,RI ,LE> So fix it by using pr_cont() where appropriate. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-02 19:20:47 +08:00
pr_cont("]");
powerpc: Print MSR TM bits in oops messages Print MSR TM bits in oops messages. This appends them to the end like this: MSR: 8000000502823031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[TE]> You get the TM[] only if at least one TM MSR bit is set. Inside the TM[], E means Enabled (bit 32), S means Suspended (bit 33), and T means Transactional (bit 34) If no bits are set, you get no TM[] output. Include rework of printbits() to handle this case. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-11-20 12:15:32 +08:00
}
}
#else
static void print_tm_bits(unsigned long val) {}
#endif
static void print_msr_bits(unsigned long val)
{
powerpc/oops: Fix missing pr_cont()s in print_msr_bits() et. al. Since the KERN_CONT changes these are being horribly split across lines, for example: MSR: 8000000000009033 < SF,EE ,ME,IR ,DR,RI ,LE> So fix it by using pr_cont() where appropriate. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-02 19:20:47 +08:00
pr_cont("<");
powerpc: Print MSR TM bits in oops messages Print MSR TM bits in oops messages. This appends them to the end like this: MSR: 8000000502823031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[TE]> You get the TM[] only if at least one TM MSR bit is set. Inside the TM[], E means Enabled (bit 32), S means Suspended (bit 33), and T means Transactional (bit 34) If no bits are set, you get no TM[] output. Include rework of printbits() to handle this case. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-11-20 12:15:32 +08:00
print_bits(val, msr_bits, ",");
print_tm_bits(val);
powerpc/oops: Fix missing pr_cont()s in print_msr_bits() et. al. Since the KERN_CONT changes these are being horribly split across lines, for example: MSR: 8000000000009033 < SF,EE ,ME,IR ,DR,RI ,LE> So fix it by using pr_cont() where appropriate. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-02 19:20:47 +08:00
pr_cont(">");
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
}
#ifdef CONFIG_PPC64
[POWERPC] Use lowercase for hex printouts in oops messages. Use lowercase for hex printouts in oops messages. The number of times I have tried to copy and paste from an oops into an objdump search... Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-03-21 09:38:19 +08:00
#define REG "%016lx"
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
#define REGS_PER_LINE 4
#define LAST_VOLATILE 13
#else
[POWERPC] Use lowercase for hex printouts in oops messages. Use lowercase for hex printouts in oops messages. The number of times I have tried to copy and paste from an oops into an objdump search... Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-03-21 09:38:19 +08:00
#define REG "%08lx"
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
#define REGS_PER_LINE 8
#define LAST_VOLATILE 12
#endif
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
void show_regs(struct pt_regs * regs)
{
int i, trap;
dump_stack: unify debug information printed by show_regs() show_regs() is inherently arch-dependent but it does make sense to print generic debug information and some archs already do albeit in slightly different forms. This patch introduces a generic function to print debug information from show_regs() so that different archs print out the same information and it's much easier to modify what's printed. show_regs_print_info() prints out the same debug info as dump_stack() does plus task and thread_info pointers. * Archs which didn't print debug info now do. alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r, metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc, um, xtensa * Already prints debug info. Replaced with show_regs_print_info(). The printed information is superset of what used to be there. arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86 * s390 is special in that it used to print arch-specific information along with generic debug info. Heiko and Martin think that the arch-specific extra isn't worth keeping s390 specfic implementation. Converted to use the generic version. Note that now all archs print the debug info before actual register dumps. An example BUG() dump follows. kernel BUG at /work/os/work/kernel/workqueue.c:4841! invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #7 Hardware name: empty empty/S3992, BIOS 080011 10/26/2007 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000 RIP: 0010:[<ffffffff8234a07e>] [<ffffffff8234a07e>] init_workqueues+0x4/0x6 RSP: 0000:ffff88007c861ec8 EFLAGS: 00010246 RAX: ffff88007c861fd8 RBX: ffffffff824466a8 RCX: 0000000000000001 RDX: 0000000000000046 RSI: 0000000000000001 RDI: ffffffff8234a07a RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a07a R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffff88007c861ef8 ffffffff81000312 ffffffff824466a8 ffff88007c85e650 0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47760 Call Trace: [<ffffffff81000312>] do_one_initcall+0x122/0x170 [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8 [<ffffffff81c47760>] ? rest_init+0x140/0x140 [<ffffffff81c4776e>] kernel_init+0xe/0xf0 [<ffffffff81c6be9c>] ret_from_fork+0x7c/0xb0 [<ffffffff81c47760>] ? rest_init+0x140/0x140 ... v2: Typo fix in x86-32. v3: CPU number dropped from show_regs_print_info() as dump_stack_print_info() has been updated to print it. s390 specific implementation dropped as requested by s390 maintainers. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Sam Ravnborg <sam@ravnborg.org> Acked-by: Chris Metcalf <cmetcalf@tilera.com> [tile bits] Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon bits] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-01 06:27:17 +08:00
show_regs_print_info(KERN_DEFAULT);
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
regs->nip, regs->link, regs->ctr);
printk("REGS: %p TRAP: %04lx %s (%s)\n",
[PATCH] namespaces: utsname: use init_utsname when appropriate In some places, particularly drivers and __init code, the init utsns is the appropriate one to use. This patch replaces those with a the init_utsname helper. Changes: Removed several uses of init_utsname(). Hope I picked all the right ones in net/ipv4/ipconfig.c. These are now changed to utsname() (the per-process namespace utsname) in the previous patch (2/7) [akpm@osdl.org: CIFS fix] Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Andrey Savochkin <saw@sw.ru> Cc: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 17:18:13 +08:00
regs, regs->trap, print_tainted(), init_utsname()->release);
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
printk("MSR: "REG" ", regs->msr);
powerpc: Print MSR TM bits in oops messages Print MSR TM bits in oops messages. This appends them to the end like this: MSR: 8000000502823031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[TE]> You get the TM[] only if at least one TM MSR bit is set. Inside the TM[], E means Enabled (bit 32), S means Suspended (bit 33), and T means Transactional (bit 34) If no bits are set, you get no TM[] output. Include rework of printbits() to handle this case. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-11-20 12:15:32 +08:00
print_msr_bits(regs->msr);
[POWERPC] Use lowercase for hex printouts in oops messages. Use lowercase for hex printouts in oops messages. The number of times I have tried to copy and paste from an oops into an objdump search... Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-03-21 09:38:19 +08:00
printk(" CR: %08lx XER: %08lx\n", regs->ccr, regs->xer);
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
trap = TRAP(regs);
powerpc: Add CFAR to oops output Now we have the CFAR saved add it to the oops output. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-07-15 03:25:12 +08:00
if ((regs->trap != 0xc00) && cpu_has_feature(CPU_FTR_CFAR))
powerpc/oops: Fix missing pr_cont()s in show_regs() Fix up our oops output by converting continuation lines to use pr_cont(). Some of these are dubious, eg. printing a continuation line which starts with a newline, but seem to work OK for now. This whole function needs a rewrite in the next release. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-03 17:45:26 +08:00
pr_cont("CFAR: "REG" ", regs->orig_gpr3);
powerpc: Print DAR and DSISR on machine check oopses Machine check exceptions set DAR and DSISR, so print them in our oops output. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-11-15 12:41:19 +08:00
if (trap == 0x200 || trap == 0x300 || trap == 0x600)
powerpc: Revert show_regs() define for readability We had an existing ifdef for 4xx & BOOKE processors that got changed to CONFIG_PPC_ADV_DEBUG_REGS. The define has nothing to do with CONFIG_PPC_ADV_DEBUG_REGS. The define really should be: #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) and not #ifdef CONFIG_PPC_ADV_DEBUG_REGS Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-10-06 10:53:38 +08:00
#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
powerpc/oops: Fix missing pr_cont()s in show_regs() Fix up our oops output by converting continuation lines to use pr_cont(). Some of these are dubious, eg. printing a continuation line which starts with a newline, but seem to work OK for now. This whole function needs a rewrite in the next release. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-03 17:45:26 +08:00
pr_cont("DEAR: "REG" ESR: "REG" ", regs->dar, regs->dsisr);
[POWERPC] Fix register labels on show_regs() message for 4xx/Book-E In a show_regs() message The DEAR and ESR were reported as DAR and DSISR which only exist on classic parts. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-07-26 13:46:15 +08:00
#else
powerpc/oops: Fix missing pr_cont()s in show_regs() Fix up our oops output by converting continuation lines to use pr_cont(). Some of these are dubious, eg. printing a continuation line which starts with a newline, but seem to work OK for now. This whole function needs a rewrite in the next release. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-03 17:45:26 +08:00
pr_cont("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr);
powerpc: Remove a few lines of oops output We waste quite a few lines in our oops output: ... MSR: 8000000000009032 <SF,EE,ME,IR,DR,RI> CR: 28044024 XER: 00000000 SOFTE: 0 CFAR: 0000000000009088 DAR: 000000000000001c, DSISR: 40000000 GPR00: c0000000000c74f0 c00000037cc1b010 c000000000d2bb30 0000000000000000 ... We can do a better job here and remove 3 lines: MSR: 8000000000009032 <SF,EE,ME,IR,DR,RI> CR: 28044024 XER: 00000000 CFAR: 0000000000009088 DAR: 0000000000000010, DSISR: 40000000 SOFTE: 1 GPR00: c0000000000e3d10 c00000037cc2fda0 c000000000d2c3a8 0000000000000001 Also move PACATMSCRATCH up, it doesn't really belong in the stack trace section. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-11-15 12:48:38 +08:00
#endif
#ifdef CONFIG_PPC64
powerpc/oops: Fix missing pr_cont()s in show_regs() Fix up our oops output by converting continuation lines to use pr_cont(). Some of these are dubious, eg. printing a continuation line which starts with a newline, but seem to work OK for now. This whole function needs a rewrite in the next release. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-03 17:45:26 +08:00
pr_cont("SOFTE: %ld ", regs->softe);
powerpc: Remove a few lines of oops output We waste quite a few lines in our oops output: ... MSR: 8000000000009032 <SF,EE,ME,IR,DR,RI> CR: 28044024 XER: 00000000 SOFTE: 0 CFAR: 0000000000009088 DAR: 000000000000001c, DSISR: 40000000 GPR00: c0000000000c74f0 c00000037cc1b010 c000000000d2bb30 0000000000000000 ... We can do a better job here and remove 3 lines: MSR: 8000000000009032 <SF,EE,ME,IR,DR,RI> CR: 28044024 XER: 00000000 CFAR: 0000000000009088 DAR: 0000000000000010, DSISR: 40000000 SOFTE: 1 GPR00: c0000000000e3d10 c00000037cc2fda0 c000000000d2c3a8 0000000000000001 Also move PACATMSCRATCH up, it doesn't really belong in the stack trace section. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-11-15 12:48:38 +08:00
#endif
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
powerpc: Only print PACATMSCRATCH in oops when TM is active If TM is not active there is no need to print PACATMSCRATCH so we can save ourselves a line. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-11-18 10:19:17 +08:00
if (MSR_TM_ACTIVE(regs->msr))
powerpc/oops: Fix missing pr_cont()s in show_regs() Fix up our oops output by converting continuation lines to use pr_cont(). Some of these are dubious, eg. printing a continuation line which starts with a newline, but seem to work OK for now. This whole function needs a rewrite in the next release. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-03 17:45:26 +08:00
pr_cont("\nPACATMSCRATCH: %016llx ", get_paca()->tm_scratch);
[POWERPC] Fix register labels on show_regs() message for 4xx/Book-E In a show_regs() message The DEAR and ESR were reported as DAR and DSISR which only exist on classic parts. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-07-26 13:46:15 +08:00
#endif
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
for (i = 0; i < 32; i++) {
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
if ((i % REGS_PER_LINE) == 0)
powerpc/oops: Fix missing pr_cont()s in show_regs() Fix up our oops output by converting continuation lines to use pr_cont(). Some of these are dubious, eg. printing a continuation line which starts with a newline, but seem to work OK for now. This whole function needs a rewrite in the next release. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-03 17:45:26 +08:00
pr_cont("\nGPR%02d: ", i);
pr_cont(REG " ", regs->gpr[i]);
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
if (i == LAST_VOLATILE && !FULL_REGS(regs))
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
break;
}
powerpc/oops: Fix missing pr_cont()s in show_regs() Fix up our oops output by converting continuation lines to use pr_cont(). Some of these are dubious, eg. printing a continuation line which starts with a newline, but seem to work OK for now. This whole function needs a rewrite in the next release. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-03 17:45:26 +08:00
pr_cont("\n");
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
#ifdef CONFIG_KALLSYMS
/*
* Lookup NIP late so we have the best change of getting the
* above info out without failing
*/
powerpc: Use new printk extension %pS to print symbols on oops This changes the oops and backtrace code to use the new %pS printk extension to print out symbols rather than manually calling print_symbol. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-07 11:44:31 +08:00
printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip);
printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
powerpc: Add transactional memory paca scratch register to show_regs Add transactional memory paca scratch register to show_regs. This is useful for debugging. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:34 +08:00
#endif
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
show_stack(current, (unsigned long *) regs->gpr[1]);
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
if (!user_mode(regs))
show_instructions(regs);
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
}
void flush_thread(void)
{
powerpc: Fix call to flush_ptrace_hw_breakpoint() Fix the error in spelling the config option for hw-breakpoints and fix the build issue that follows. Signed-off by: K.Prasad <prasad@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-02-10 12:44:35 +08:00
#ifdef CONFIG_HAVE_HW_BREAKPOINT
powerpc, hw_breakpoints: Implement hw_breakpoints for 64-bit server processors Implement perf-events based hw-breakpoint interfaces for PowerPC 64-bit server (Book III S) processors. This allows access to a given location to be used as an event that can be counted or profiled by the perf_events subsystem. This is done using the DABR (data breakpoint register), which can also be used for process debugging via ptrace. When perf_event hw_breakpoint support is configured in, the perf_event subsystem manages the DABR and arbitrates access to it, and ptrace then creates a perf_event when it is requested to set a data breakpoint. [Adopted suggestions from Paul Mackerras <paulus@samba.org> to - emulate_step() all system-wide breakpoints and single-step only the per-task breakpoints - perform arch-specific cleanup before unregistration through arch_unregister_hw_breakpoint() ] Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2010-06-15 14:05:19 +08:00
flush_ptrace_hw_breakpoint(current);
powerpc: Fix call to flush_ptrace_hw_breakpoint() Fix the error in spelling the config option for hw-breakpoints and fix the build issue that follows. Signed-off by: K.Prasad <prasad@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-02-10 12:44:35 +08:00
#else /* CONFIG_HAVE_HW_BREAKPOINT */
powerpc/booke: Add support for advanced debug registers powerpc/booke: Add support for advanced debug registers From: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Based on patches originally written by Torez Smith. This patch defines context switch and trap related functionality for BookE specific Debug Registers. It adds support to ptrace() for setting and getting BookE related Debug Registers Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <dwg@au1.ibm.com> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Sergio Durigan Junior <sergiodj@br.ibm.com> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com> Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-08 19:51:18 +08:00
set_debug_reg_defaults(&current->thread);
powerpc: Fix call to flush_ptrace_hw_breakpoint() Fix the error in spelling the config option for hw-breakpoints and fix the build issue that follows. Signed-off by: K.Prasad <prasad@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-02-10 12:44:35 +08:00
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
}
void
release_thread(struct task_struct *t)
{
}
/*
fork: move the real prepare_to_copy() users to arch_dup_task_struct() Historical prepare_to_copy() is mostly a no-op, duplicated for majority of the architectures and the rest following the x86 model of flushing the extended register state like fpu there. Remove it and use the arch_dup_task_struct() instead. Suggested-by: Oleg Nesterov <oleg@redhat.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1336692811-30576-1-git-send-email-suresh.b.siddha@intel.com Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Chris Zankel <chris@zankel.net> Cc: Richard Henderson <rth@twiddle.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mark Salter <msalter@redhat.com> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-17 06:03:51 +08:00
* this gets called so that we can store coprocessor state into memory and
* copy the current task into the new thread.
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
*/
fork: move the real prepare_to_copy() users to arch_dup_task_struct() Historical prepare_to_copy() is mostly a no-op, duplicated for majority of the architectures and the rest following the x86 model of flushing the extended register state like fpu there. Remove it and use the arch_dup_task_struct() instead. Suggested-by: Oleg Nesterov <oleg@redhat.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1336692811-30576-1-git-send-email-suresh.b.siddha@intel.com Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Chris Zankel <chris@zankel.net> Cc: Richard Henderson <rth@twiddle.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mark Salter <msalter@redhat.com> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-17 06:03:51 +08:00
int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
{
powerpc: create flush_all_to_thread() Create a single function that flushes everything (FP, VMX, VSX, SPE). Doing this all at once means we only do one MSR write. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-29 08:44:09 +08:00
flush_all_to_thread(src);
powerpc/tm: Fix crash when forking inside a transaction When we fork/clone we currently don't copy any of the TM state to the new thread. This results in a TM bad thing (program check) when the new process is switched in as the kernel does a tmrechkpt with TEXASR FS not set. Also, since R1 is from userspace, we trigger the bad kernel stack pointer detection. So we end up with something like this: Bad kernel stack pointer 0 at c0000000000404fc cpu 0x2: Vector: 700 (Program Check) at [c00000003ffefd40] pc: c0000000000404fc: restore_gprs+0xc0/0x148 lr: 0000000000000000 sp: 0 msr: 9000000100201030 current = 0xc000001dd1417c30 paca = 0xc00000000fe00800 softe: 0 irq_happened: 0x01 pid = 0, comm = swapper/2 WARNING: exception is not recoverable, can't continue The below fixes this by flushing the TM state before we copy the task_struct to the clone. To do this we go through the tmreclaim patch, which removes the checkpointed registers from the CPU and transitions the CPU out of TM suspend mode. Hence we need to call tmrechkpt after to restore the checkpointed state and the TM mode for the current task. To make this fail from userspace is simply: tbegin li r0, 2 sc <boom> Kudos to Adhemerval Zanella Neto for finding this. Signed-off-by: Michael Neuling <mikey@neuling.org> cc: Adhemerval Zanella Neto <azanella@br.ibm.com> cc: stable@vger.kernel.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-03-03 11:21:40 +08:00
/*
* Flush TM state out so we can copy it. __switch_to_tm() does this
* flush but it removes the checkpointed state from the current CPU and
* transitions the CPU out of TM mode. Hence we need to call
* tm_recheckpoint_new_task() (on the same task) to restore the
* checkpointed state back and the TM mode.
powerpc: tm: Enable transactional memory (TM) lazily for userspace Currently the MSR TM bit is always set if the hardware is TM capable. This adds extra overhead as it means the TM SPRS (TFHAR, TEXASR and TFAIR) must be swapped for each process regardless of if they use TM. For processes that don't use TM the TM MSR bit can be turned off allowing the kernel to avoid the expensive swap of the TM registers. A TM unavailable exception will occur if a thread does use TM and the kernel will enable MSR_TM and leave it so for some time afterwards. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-14 16:02:16 +08:00
*
* Can't pass dst because it isn't ready. Doesn't matter, passing
* dst is only important for __switch_to()
powerpc/tm: Fix crash when forking inside a transaction When we fork/clone we currently don't copy any of the TM state to the new thread. This results in a TM bad thing (program check) when the new process is switched in as the kernel does a tmrechkpt with TEXASR FS not set. Also, since R1 is from userspace, we trigger the bad kernel stack pointer detection. So we end up with something like this: Bad kernel stack pointer 0 at c0000000000404fc cpu 0x2: Vector: 700 (Program Check) at [c00000003ffefd40] pc: c0000000000404fc: restore_gprs+0xc0/0x148 lr: 0000000000000000 sp: 0 msr: 9000000100201030 current = 0xc000001dd1417c30 paca = 0xc00000000fe00800 softe: 0 irq_happened: 0x01 pid = 0, comm = swapper/2 WARNING: exception is not recoverable, can't continue The below fixes this by flushing the TM state before we copy the task_struct to the clone. To do this we go through the tmreclaim patch, which removes the checkpointed registers from the CPU and transitions the CPU out of TM suspend mode. Hence we need to call tmrechkpt after to restore the checkpointed state and the TM mode for the current task. To make this fail from userspace is simply: tbegin li r0, 2 sc <boom> Kudos to Adhemerval Zanella Neto for finding this. Signed-off-by: Michael Neuling <mikey@neuling.org> cc: Adhemerval Zanella Neto <azanella@br.ibm.com> cc: stable@vger.kernel.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-03-03 11:21:40 +08:00
*/
powerpc: tm: Always use fp_state and vr_state to store live registers There is currently an inconsistency as to how the entire CPU register state is saved and restored when a thread uses transactional memory (TM). Using transactional memory results in the CPU having duplicated (almost) all of its register state. This duplication results in a set of registers which can be considered 'live', those being currently modified by the instructions being executed and another set that is frozen at a point in time. On context switch, both sets of state have to be saved and (later) restored. These two states are often called a variety of different things. Common terms for the state which only exists after the CPU has entered a transaction (performed a TBEGIN instruction) in hardware are 'transactional' or 'speculative'. Between a TBEGIN and a TEND or TABORT (or an event that causes the hardware to abort), regardless of the use of TSUSPEND the transactional state can be referred to as the live state. The second state is often to referred to as the 'checkpointed' state and is a duplication of the live state when the TBEGIN instruction is executed. This state is kept in the hardware and will be rolled back to on transaction failure. Currently all the registers stored in pt_regs are ALWAYS the live registers, that is, when a thread has transactional registers their values are stored in pt_regs and the checkpointed state is in ckpt_regs. A strange opposite is true for fp_state/vr_state. When a thread is non transactional fp_state/vr_state holds the live registers. When a thread has initiated a transaction fp_state/vr_state holds the checkpointed state and transact_fp/transact_vr become the structure which holds the live state (at this point it is a transactional state). This method creates confusion as to where the live state is, in some circumstances it requires extra work to determine where to put the live state and prevents the use of common functions designed (probably before TM) to save the live state. With this patch pt_regs, fp_state and vr_state all represent the same thing and the other structures [pending rename] are for checkpointed state. Acked-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23 14:18:24 +08:00
__switch_to_tm(src, src);
powerpc/perf: Core EBB support for 64-bit book3s Add support for EBB (Event Based Branches) on 64-bit book3s. See the included documentation for more details. EBBs are a feature which allows the hardware to branch directly to a specified user space address when a PMU event overflows. This can be used by programs for self-monitoring with no kernel involvement in the inner loop. Most of the logic is in the generic book3s code, primarily to avoid a proliferation of PMU callbacks. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-28 16:15:16 +08:00
fork: move the real prepare_to_copy() users to arch_dup_task_struct() Historical prepare_to_copy() is mostly a no-op, duplicated for majority of the architectures and the rest following the x86 model of flushing the extended register state like fpu there. Remove it and use the arch_dup_task_struct() instead. Suggested-by: Oleg Nesterov <oleg@redhat.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1336692811-30576-1-git-send-email-suresh.b.siddha@intel.com Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Chris Zankel <chris@zankel.net> Cc: Richard Henderson <rth@twiddle.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mark Salter <msalter@redhat.com> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-17 06:03:51 +08:00
*dst = *src;
powerpc/perf: Core EBB support for 64-bit book3s Add support for EBB (Event Based Branches) on 64-bit book3s. See the included documentation for more details. EBBs are a feature which allows the hardware to branch directly to a specified user space address when a PMU event overflows. This can be used by programs for self-monitoring with no kernel involvement in the inner loop. Most of the logic is in the generic book3s code, primarily to avoid a proliferation of PMU callbacks. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-28 16:15:16 +08:00
clear_task_ebb(dst);
fork: move the real prepare_to_copy() users to arch_dup_task_struct() Historical prepare_to_copy() is mostly a no-op, duplicated for majority of the architectures and the rest following the x86 model of flushing the extended register state like fpu there. Remove it and use the arch_dup_task_struct() instead. Suggested-by: Oleg Nesterov <oleg@redhat.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1336692811-30576-1-git-send-email-suresh.b.siddha@intel.com Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Chris Zankel <chris@zankel.net> Cc: Richard Henderson <rth@twiddle.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mark Salter <msalter@redhat.com> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-17 06:03:51 +08:00
return 0;
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
}
powerpc: Pull out ksp_vsid logic into a helper The previous patch left a bit of a wart in copy_process(). Clean it up a bit by moving the logic out into a helper. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-07-10 10:29:21 +08:00
static void setup_ksp_vsid(struct task_struct *p, unsigned long sp)
{
#ifdef CONFIG_PPC_STD_MMU_64
unsigned long sp_vsid;
unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
powerpc/mm/radix: Use STD_MMU_64 to properly isolate hash related code We also use MMU_FTR_RADIX to branch out from code path specific to hash. No functionality change. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 21:26:07 +08:00
if (radix_enabled())
return;
powerpc: Pull out ksp_vsid logic into a helper The previous patch left a bit of a wart in copy_process(). Clean it up a bit by moving the logic out into a helper. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-07-10 10:29:21 +08:00
if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T)
<< SLB_VSID_SHIFT_1T;
else
sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M)
<< SLB_VSID_SHIFT;
sp_vsid |= SLB_VSID_KERNEL | llp;
p->thread.ksp_vsid = sp_vsid;
#endif
}
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
/*
* Copy a thread..
*/
powerpc: Per process DSCR + some fixes (try#4) The DSCR (aka Data Stream Control Register) is supported on some server PowerPC chips and allow some control over the prefetch of data streams. This patch allows the value to be specified per thread by emulating the corresponding mfspr and mtspr instructions. Children of such threads inherit the value. Other threads use a default value that can be specified in sysfs - /sys/devices/system/cpu/dscr_default. If a thread starts with non default value in the sysfs entry, all children threads inherit this non default value even if the sysfs value is changed later. Signed-off-by: Alexey Kardashevskiy <aik@au1.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-03-02 23:18:48 +08:00
powerpc/kernel: Rename copy_thread() 'arg' argument to 'kthread_arg' The 'arg' argument to copy_thread() is only ever used when forking a new kernel thread. Hence, rename it to 'kthread_arg' for clarity. Signed-off-by: Alex Dowad <alexinbeijing@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-03-14 02:14:46 +08:00
/*
* Copy architecture-specific thread state
*/
Simplify copy_thread() First argument unused since 2.3.11. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-03 07:56:59 +08:00
int copy_thread(unsigned long clone_flags, unsigned long usp,
powerpc/kernel: Rename copy_thread() 'arg' argument to 'kthread_arg' The 'arg' argument to copy_thread() is only ever used when forking a new kernel thread. Hence, rename it to 'kthread_arg' for clarity. Signed-off-by: Alex Dowad <alexinbeijing@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-03-14 02:14:46 +08:00
unsigned long kthread_arg, struct task_struct *p)
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
{
struct pt_regs *childregs, *kregs;
extern void ret_from_fork(void);
powerpc: split ret_from_fork ... and get rid of in-kernel syscalls in kernel_thread() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-13 06:32:42 +08:00
extern void ret_from_kernel_thread(void);
void (*f)(void);
[PATCH] powerpc: task_stack_page() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 17:06:02 +08:00
unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
powerpc/livepatch: Add livepatch stack to struct thread_info In order to support live patching we need to maintain an alternate stack of TOC & LR values. We use the base of the stack for this, and store the "live patch stack pointer" in struct thread_info. Unlike the other fields of thread_info, we can not statically initialise that value, so it must be done at run time. This patch just adds the code to support that, it is not enabled until the next patch which actually adds live patch support. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Balbir Singh <bsingharora@gmail.com>
2016-03-24 19:04:04 +08:00
struct thread_info *ti = task_thread_info(p);
klp_init_thread_info(ti);
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
/* Copy registers */
sp -= sizeof(struct pt_regs);
childregs = (struct pt_regs *) sp;
powerpc: make fork_idle() take the common "kernel thread" path in copy_thread() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-22 10:33:39 +08:00
if (unlikely(p->flags & PF_KTHREAD)) {
powerpc/kernel: Rename copy_thread() 'arg' argument to 'kthread_arg' The 'arg' argument to copy_thread() is only ever used when forking a new kernel thread. Hence, rename it to 'kthread_arg' for clarity. Signed-off-by: Alex Dowad <alexinbeijing@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-03-14 02:14:46 +08:00
/* kernel thread */
powerpc: split ret_from_fork ... and get rid of in-kernel syscalls in kernel_thread() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-13 06:32:42 +08:00
memset(childregs, 0, sizeof(struct pt_regs));
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
childregs->gpr[1] = sp + sizeof(struct pt_regs);
powerpc: Fix kernel thread creation on ABIv2 Change how we setup registers for ret_from_kernel_thread. In ABIv1, instead of passing a function descriptor in, dereference it and pass the target in directly. Use ppc_global_function_entry to get it right on both ABIv1 and ABIv2. Signed-off-by: Anton Blanchard <anton@samba.org>
2014-02-04 13:08:51 +08:00
/* function */
if (usp)
childregs->gpr[14] = ppc_function_entry((void *)usp);
powerpc: split ret_from_fork ... and get rid of in-kernel syscalls in kernel_thread() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-13 06:32:42 +08:00
#ifdef CONFIG_PPC64
[PATCH] powerpc: task_thread_info() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 17:06:01 +08:00
clear_tsk_thread_flag(p, TIF_32BIT);
powerpc: switch to saner kernel_execve() semantics Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11 20:41:43 +08:00
childregs->softe = 1;
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
#endif
powerpc/kernel: Rename copy_thread() 'arg' argument to 'kthread_arg' The 'arg' argument to copy_thread() is only ever used when forking a new kernel thread. Hence, rename it to 'kthread_arg' for clarity. Signed-off-by: Alex Dowad <alexinbeijing@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-03-14 02:14:46 +08:00
childregs->gpr[15] = kthread_arg;
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
p->thread.regs = NULL; /* no user register state */
powerpc: switch to saner kernel_execve() semantics Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11 20:41:43 +08:00
ti->flags |= _TIF_RESTOREALL;
powerpc: split ret_from_fork ... and get rid of in-kernel syscalls in kernel_thread() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-13 06:32:42 +08:00
f = ret_from_kernel_thread;
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
} else {
powerpc/kernel: Rename copy_thread() 'arg' argument to 'kthread_arg' The 'arg' argument to copy_thread() is only ever used when forking a new kernel thread. Hence, rename it to 'kthread_arg' for clarity. Signed-off-by: Alex Dowad <alexinbeijing@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-03-14 02:14:46 +08:00
/* user thread */
flagday: don't pass regs to copy_thread() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-23 10:51:14 +08:00
struct pt_regs *regs = current_pt_regs();
powerpc: split ret_from_fork ... and get rid of in-kernel syscalls in kernel_thread() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-13 06:32:42 +08:00
CHECK_FULL_REGS(regs);
*childregs = *regs;
powerpc: put the "zero usp means using parent's stack pointer" to copy_thread() simplifies callers, at that... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-22 10:28:43 +08:00
if (usp)
childregs->gpr[1] = usp;
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
p->thread.regs = childregs;
powerpc: split ret_from_fork ... and get rid of in-kernel syscalls in kernel_thread() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-13 06:32:42 +08:00
childregs->gpr[3] = 0; /* Result from fork() */
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
if (clone_flags & CLONE_SETTLS) {
#ifdef CONFIG_PPC64
powerpc: Use is_32bit_task() helper to test 32 bit binary Use is_32bit_task() helper to test 32 bit binary. Signed-off-by: Denis Kirjanov <dkirjanov@kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-07-30 06:04:39 +08:00
if (!is_32bit_task())
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
childregs->gpr[13] = childregs->gpr[6];
else
#endif
childregs->gpr[2] = childregs->gpr[6];
}
powerpc: split ret_from_fork ... and get rid of in-kernel syscalls in kernel_thread() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-13 06:32:42 +08:00
f = ret_from_fork;
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
}
powerpc: Explicitly disable math features when copying thread Currently when threads get scheduled off they always giveup the FPU, Altivec (VMX) and Vector (VSX) units if they were using them. When they are scheduled back on a fault is then taken to enable each facility and load registers. As a result explicitly disabling FPU/VMX/VSX has not been necessary. Future changes and optimisations remove this mandatory giveup and fault which could cause calls such as clone() and fork() to copy threads and run them later with FPU/VMX/VSX enabled but no registers loaded. This patch starts the process of having MSR_{FP,VEC,VSX} mean that a threads registers are hot while not having MSR_{FP,VEC,VSX} means that the registers must be loaded. This allows for a smarter return to userspace. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:46 +08:00
childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX);
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
sp -= STACK_FRAME_OVERHEAD;
/*
* The way this works is that at some point in the future
* some task will call _switch to switch to the new task.
* That will pop off the stack frame created below and start
* the new task running at ret_from_fork. The new task will
* do some house keeping and then return from the fork or clone
* system call, using the stack frame created above.
*/
powerpc: Fix MAX_STACK_TRACE_ENTRIES too low warning again Saw this warning again, and this time from the ret_from_fork path. It seems we could clear the back chain earlier in copy_thread(), which could cover both path, and also fix potential lockdep usage in schedule_tail(), or exception occurred before we clear the back chain. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-07 06:44:41 +08:00
((unsigned long *)sp)[0] = 0;
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
sp -= sizeof(struct pt_regs);
kregs = (struct pt_regs *) sp;
sp -= STACK_FRAME_OVERHEAD;
p->thread.ksp = sp;
powerpc: Remove ksp_limit on ppc64 We've been keeping that field in thread_struct for a while, it contains the "limit" of the current stack pointer and is meant to be used for detecting stack overflows. It has a few problems however: - First, it was never actually *used* on 64-bit. Set and updated but not actually exploited - When switching stack to/from irq and softirq stacks, it's update is racy unless we hard disable interrupts, which is costly. This is fine on 32-bit as we don't soft-disable there but not on 64-bit. Thus rather than fixing 2 in order to implement 1 in some hypothetical future, let's remove the code completely from 64-bit. In order to avoid a clutter of ifdef's, we remove the updates from C code completely during interrupt stack switching, and instead maintain it from the asm helper that is used to do the stack switching in the first place. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-24 13:17:21 +08:00
#ifdef CONFIG_PPC32
[POWERPC] Add IRQSTACKS support on ppc32 This makes it possible to use separate stacks for hard and soft IRQs on 32-bit powerpc as well as on 64-bit. The code for 32-bit is just the 32-bit analog of the 64-bit code. * Added allocation and initialization of the irq stacks. We limit the stacks to be in lowmem for ppc32. * Implemented ppc32 versions of call_do_softirq() and call_handle_irq() to switch the stack pointers * Reworked how we do stack overflow detection. We now keep around the limit of the stack in the thread_struct and compare against the limit to see if we've overflowed. We can now use this on ppc64 if desired. [ paulus@samba.org: Fixed bug on 6xx where we need to reload r9 with the thread_info pointer. ] Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-28 14:21:22 +08:00
p->thread.ksp_limit = (unsigned long)task_stack_page(p) +
_ALIGN_UP(sizeof(struct thread_info), 16);
powerpc: Remove ksp_limit on ppc64 We've been keeping that field in thread_struct for a while, it contains the "limit" of the current stack pointer and is meant to be used for detecting stack overflows. It has a few problems however: - First, it was never actually *used* on 64-bit. Set and updated but not actually exploited - When switching stack to/from irq and softirq stacks, it's update is racy unless we hard disable interrupts, which is costly. This is fine on 32-bit as we don't soft-disable there but not on 64-bit. Thus rather than fixing 2 in order to implement 1 in some hypothetical future, let's remove the code completely from 64-bit. In order to avoid a clutter of ifdef's, we remove the updates from C code completely during interrupt stack switching, and instead maintain it from the asm helper that is used to do the stack switching in the first place. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-24 13:17:21 +08:00
#endif
ptrace/powerpc: Don't flush_ptrace_hw_breakpoint() on fork() arch_dup_task_struct() does flush_ptrace_hw_breakpoint(src), this destroys the parent's breakpoints for no reason. We should clear child->thread.ptrace_bps[] copied by dup_task_struct() instead. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-04-21 14:47:59 +08:00
#ifdef CONFIG_HAVE_HW_BREAKPOINT
p->thread.ptrace_bps[0] = NULL;
#endif
powerpc: Provide for giveup_fpu/altivec to save state in alternate location This provides a facility which is intended for use by KVM, where the contents of the FP/VSX and VMX (Altivec) registers can be saved away to somewhere other than the thread_struct when kernel code wants to use floating point or VMX instructions. This is done by providing a pointer in the thread_struct to indicate where the state should be saved to. The giveup_fpu() and giveup_altivec() functions test these pointers and save state to the indicated location if they are non-NULL. Note that the MSR_FP/VEC bits in task->thread.regs->msr are still used to indicate whether the CPU register state is live, even when an alternate save location is being used. This also provides load_fp_state() and load_vr_state() functions, which load up FP/VSX and VMX state from memory into the CPU registers, and corresponding store_fp_state() and store_vr_state() functions, which store FP/VSX and VMX state into memory from the CPU registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-10 18:21:10 +08:00
p->thread.fp_save_area = NULL;
#ifdef CONFIG_ALTIVEC
p->thread.vr_save_area = NULL;
#endif
powerpc: Pull out ksp_vsid logic into a helper The previous patch left a bit of a wart in copy_process(). Clean it up a bit by moving the logic out into a helper. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-07-10 10:29:21 +08:00
setup_ksp_vsid(p, sp);
powerpc: Per process DSCR + some fixes (try#4) The DSCR (aka Data Stream Control Register) is supported on some server PowerPC chips and allow some control over the prefetch of data streams. This patch allows the value to be specified per thread by emulating the corresponding mfspr and mtspr instructions. Children of such threads inherit the value. Other threads use a default value that can be specified in sysfs - /sys/devices/system/cpu/dscr_default. If a thread starts with non default value in the sysfs entry, all children threads inherit this non default value even if the sysfs value is changed later. Signed-off-by: Alexey Kardashevskiy <aik@au1.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-03-02 23:18:48 +08:00
#ifdef CONFIG_PPC64
if (cpu_has_feature(CPU_FTR_DSCR)) {
powerpc: Fix DSCR inheritance in copy_thread() If the default DSCR is non zero we set thread.dscr_inherit in copy_thread() meaning the new thread and all its children will ignore future updates to the default DSCR. This is not intended and is a change in behaviour that a number of our users have hit. We just need to inherit thread.dscr and thread.dscr_inherit from the parent which ends up being much simpler. This was found with the following test case: http://ozlabs.org/~anton/junkcode/dscr_default_test.c Signed-off-by: Anton Blanchard <anton@samba.org> Cc: <stable@kernel.org> # 3.0+ Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-04 00:49:47 +08:00
p->thread.dscr_inherit = current->thread.dscr_inherit;
powerpc: Fix DSCR inheritance over fork() Two DSCR tests have a hack in them: /* * XXX: Force a context switch out so that DSCR * current value is copied into the thread struct * which is required for the child to inherit the * changed value. */ sleep(1); We should not be working around this in the testcase, it is a kernel bug. Fix it by copying the current DSCR to the child, instead of what we had in the thread struct at last context switch. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-09 17:11:47 +08:00
p->thread.dscr = mfspr(SPRN_DSCR);
powerpc: Per process DSCR + some fixes (try#4) The DSCR (aka Data Stream Control Register) is supported on some server PowerPC chips and allow some control over the prefetch of data streams. This patch allows the value to be specified per thread by emulating the corresponding mfspr and mtspr instructions. Children of such threads inherit the value. Other threads use a default value that can be specified in sysfs - /sys/devices/system/cpu/dscr_default. If a thread starts with non default value in the sysfs entry, all children threads inherit this non default value even if the sysfs value is changed later. Signed-off-by: Alexey Kardashevskiy <aik@au1.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-03-02 23:18:48 +08:00
}
powerpc: Define ppr in thread_struct [PATCH 4/6] powerpc: Define ppr in thread_struct ppr in thread_struct is used to save PPR and restore it before process exits from kernel. This patch sets the default priority to 3 when tasks are created such that users can use 4 for higher priority tasks. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-07 05:49:56 +08:00
if (cpu_has_feature(CPU_FTR_HAS_PPR))
p->thread.ppr = INIT_PPR;
powerpc: Per process DSCR + some fixes (try#4) The DSCR (aka Data Stream Control Register) is supported on some server PowerPC chips and allow some control over the prefetch of data streams. This patch allows the value to be specified per thread by emulating the corresponding mfspr and mtspr instructions. Children of such threads inherit the value. Other threads use a default value that can be specified in sysfs - /sys/devices/system/cpu/dscr_default. If a thread starts with non default value in the sysfs entry, all children threads inherit this non default value even if the sysfs value is changed later. Signed-off-by: Alexey Kardashevskiy <aik@au1.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-03-02 23:18:48 +08:00
#endif
powerpc: Fix kernel thread creation on ABIv2 Change how we setup registers for ret_from_kernel_thread. In ABIv1, instead of passing a function descriptor in, dereference it and pass the target in directly. Use ppc_global_function_entry to get it right on both ABIv1 and ABIv2. Signed-off-by: Anton Blanchard <anton@samba.org>
2014-02-04 13:08:51 +08:00
kregs->nip = ppc_function_entry(f);
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
return 0;
}
/*
* Set up a thread for executing a new program
*/
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
{
[PATCH] powerpc: Don't blow away load_addr in start_thread The patch to make process.c work for 32-bit and 64-bit (06d67d54741a5bfefa31945ef195dfa748c29025) broke some 64-bit binaries. We were blowing away load_addr in gpr[2], so we weren't properly relocating the entry point. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-21 14:01:33 +08:00
#ifdef CONFIG_PPC64
unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
#endif
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
/*
* If we exec out of a kernel thread then thread.regs will not be
* set. Do it now.
*/
if (!current->thread.regs) {
[PATCH] powerpc: task_stack_page() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 17:06:02 +08:00
struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
current->thread.regs = regs - 1;
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
}
powerpc/tm: Always reclaim in start_thread() for exec() class syscalls Userspace can quite legitimately perform an exec() syscall with a suspended transaction. exec() does not return to the old process, rather it load a new one and starts that, the expectation therefore is that the new process starts not in a transaction. Currently exec() is not treated any differently to any other syscall which creates problems. Firstly it could allow a new process to start with a suspended transaction for a binary that no longer exists. This means that the checkpointed state won't be valid and if the suspended transaction were ever to be resumed and subsequently aborted (a possibility which is exceedingly likely as exec()ing will likely doom the transaction) the new process will jump to invalid state. Secondly the incorrect attempt to keep the transactional state while still zeroing state for the new process creates at least two TM Bad Things. The first triggers on the rfid to return to userspace as start_thread() has given the new process a 'clean' MSR but the suspend will still be set in the hardware MSR. The second TM Bad Thing triggers in __switch_to() as the processor is still transactionally suspended but __switch_to() wants to zero the TM sprs for the new process. This is an example of the outcome of calling exec() with a suspended transaction. Note the first 700 is likely the first TM bad thing decsribed earlier only the kernel can't report it as we've loaded userspace registers. c000000000009980 is the rfid in fast_exception_return() Bad kernel stack pointer 3fffcfa1a370 at c000000000009980 Oops: Bad kernel stack pointer, sig: 6 [#1] CPU: 0 PID: 2006 Comm: tm-execed Not tainted NIP: c000000000009980 LR: 0000000000000000 CTR: 0000000000000000 REGS: c00000003ffefd40 TRAP: 0700 Not tainted MSR: 8000000300201031 <SF,ME,IR,DR,LE,TM[SE]> CR: 00000000 XER: 00000000 CFAR: c0000000000098b4 SOFTE: 0 PACATMSCRATCH: b00000010000d033 GPR00: 0000000000000000 00003fffcfa1a370 0000000000000000 0000000000000000 GPR04: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR12: 00003fff966611c0 0000000000000000 0000000000000000 0000000000000000 NIP [c000000000009980] fast_exception_return+0xb0/0xb8 LR [0000000000000000] (null) Call Trace: Instruction dump: f84d0278 e9a100d8 7c7b03a6 e84101a0 7c4ff120 e8410170 7c5a03a6 e8010070 e8410080 e8610088 e8810090 e8210078 <4c000024> 48000000 e8610178 88ed023b Kernel BUG at c000000000043e80 [verbose debug info unavailable] Unexpected TM Bad Thing exception at c000000000043e80 (msr 0x201033) Oops: Unrecoverable exception, sig: 6 [#2] CPU: 0 PID: 2006 Comm: tm-execed Tainted: G D task: c0000000fbea6d80 ti: c00000003ffec000 task.ti: c0000000fb7ec000 NIP: c000000000043e80 LR: c000000000015a24 CTR: 0000000000000000 REGS: c00000003ffef7e0 TRAP: 0700 Tainted: G D MSR: 8000000300201033 <SF,ME,IR,DR,RI,LE,TM[SE]> CR: 28002828 XER: 00000000 CFAR: c000000000015a20 SOFTE: 0 PACATMSCRATCH: b00000010000d033 GPR00: 0000000000000000 c00000003ffefa60 c000000000db5500 c0000000fbead000 GPR04: 8000000300001033 2222222222222222 2222222222222222 00000000ff160000 GPR08: 0000000000000000 800000010000d033 c0000000fb7e3ea0 c00000000fe00004 GPR12: 0000000000002200 c00000000fe00000 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 c0000000fbea7410 00000000ff160000 GPR24: c0000000ffe1f600 c0000000fbea8700 c0000000fbea8700 c0000000fbead000 GPR28: c000000000e20198 c0000000fbea6d80 c0000000fbeab680 c0000000fbea6d80 NIP [c000000000043e80] tm_restore_sprs+0xc/0x1c LR [c000000000015a24] __switch_to+0x1f4/0x420 Call Trace: Instruction dump: 7c800164 4e800020 7c0022a6 f80304a8 7c0222a6 f80304b0 7c0122a6 f80304b8 4e800020 e80304a8 7c0023a6 e80304b0 <7c0223a6> e80304b8 7c0123a6 4e800020 This fixes CVE-2016-5828. Fixes: bc2a9408fa65 ("powerpc: Hook in new transactional memory code") Cc: stable@vger.kernel.org # v3.9+ Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-06-17 12:58:34 +08:00
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
/*
* Clear any transactional state, we're exec()ing. The cause is
* not important as there will never be a recheckpoint so it's not
* user visible.
*/
if (MSR_TM_SUSPENDED(mfmsr()))
tm_reclaim_current(0);
#endif
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
memset(regs->gpr, 0, sizeof(regs->gpr));
regs->ctr = 0;
regs->link = 0;
regs->xer = 0;
regs->ccr = 0;
regs->gpr[1] = sp;
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
[POWERPC] Ensure FULL_REGS on exec When PTRACE_O_TRACEEXEC is used, a ptrace call to fetch the registers at the PTRACE_EVENT_EXEC stop (PTRACE_PEEKUSR) will oops in CHECK_FULL_REGS. With recent versions, "gdb --args /bin/sh -c 'exec /bin/true'" and "run" at the (gdb) prompt is sufficient to produce this. I also have written an isolated test case, see https://bugzilla.redhat.com/show_bug.cgi?id=301791#c15. This change fixes the problem by clearing the low bit of pt_regs.trap in start_thread so that FULL_REGS is true again. This is correct since all of the GPRs that "full" refers to are cleared in start_thread. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-09-25 07:52:44 +08:00
/*
* We have just cleared all the nonvolatile GPRs, so make
* FULL_REGS(regs) return true. This is necessary to allow
* ptrace to examine the thread immediately after exec.
*/
regs->trap &= ~1UL;
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
#ifdef CONFIG_PPC32
regs->mq = 0;
regs->nip = start;
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
regs->msr = MSR_USER;
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
#else
powerpc: Use is_32bit_task() helper to test 32 bit binary Use is_32bit_task() helper to test 32 bit binary. Signed-off-by: Denis Kirjanov <dkirjanov@kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-07-30 06:04:39 +08:00
if (!is_32bit_task()) {
powerpc: ELF2 binaries launched directly. No function descriptor, but we set r12 up and set TIF_RESTOREALL as it normally isn't restored on return from syscall. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-11-20 19:15:02 +08:00
unsigned long entry;
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
powerpc: ELF2 binaries launched directly. No function descriptor, but we set r12 up and set TIF_RESTOREALL as it normally isn't restored on return from syscall. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-11-20 19:15:02 +08:00
if (is_elf2_task()) {
/* Look ma, no function descriptors! */
entry = start;
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
powerpc: ELF2 binaries launched directly. No function descriptor, but we set r12 up and set TIF_RESTOREALL as it normally isn't restored on return from syscall. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-11-20 19:15:02 +08:00
/*
* Ulrich says:
* The latest iteration of the ABI requires that when
* calling a function (at its global entry point),
* the caller must ensure r12 holds the entry point
* address (so that the function can quickly
* establish addressability).
*/
regs->gpr[12] = start;
/* Make sure that's restored on entry to userspace. */
set_thread_flag(TIF_RESTOREALL);
} else {
unsigned long toc;
/* start is a relocated pointer to the function
* descriptor for the elf _start routine. The first
* entry in the function descriptor is the entry
* address of _start and the second entry is the TOC
* value we need to use.
*/
__get_user(entry, (unsigned long __user *)start);
__get_user(toc, (unsigned long __user *)start+1);
/* Check whether the e_entry function descriptor entries
* need to be relocated before we can use them.
*/
if (load_addr != 0) {
entry += load_addr;
toc += load_addr;
}
regs->gpr[2] = toc;
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
}
regs->nip = entry;
regs->msr = MSR_USER64;
ppc64: merge binfmt_elf32.c and use start_thread for both 32 and 64 bit bineries. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
2005-10-13 11:40:54 +08:00
} else {
regs->nip = start;
regs->gpr[2] = 0;
regs->msr = MSR_USER32;
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
}
#endif
powerpc: Add VSX context save/restore, ptrace and signal support This patch extends the floating point save and restore code to use the VSX load/stores when VSX is available. This will make FP context save/restore marginally slower on FP only code, when VSX is available, as it has to load/store 128bits rather than just 64bits. Mixing FP, VMX and VSX code will get constant architected state. The signals interface is extended to enable access to VSR 0-31 doubleword 1 after discussions with tool chain maintainers. Backward compatibility is maintained. The ptrace interface is also extended to allow access to VSR 0-31 full registers. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-25 12:07:18 +08:00
#ifdef CONFIG_VSX
current->thread.used_vsr = 0;
#endif
powerpc: Put FP/VSX and VR state into structures This creates new 'thread_fp_state' and 'thread_vr_state' structures to store FP/VSX state (including FPSCR) and Altivec/VSX state (including VSCR), and uses them in the thread_struct. In the thread_fp_state, the FPRs and VSRs are represented as u64 rather than double, since we rarely perform floating-point computations on the values, and this will enable the structures to be used in KVM code as well. Similarly FPSCR is now a u64 rather than a structure of two 32-bit values. This takes the offsets out of the macros such as SAVE_32FPRS, REST_32FPRS, etc. This enables the same macros to be used for normal and transactional state, enabling us to delete the transactional versions of the macros. This also removes the unused do_load_up_fpu and do_load_up_altivec, which were in fact buggy since they didn't create large enough stack frames to account for the fact that load_up_fpu and load_up_altivec are not designed to be called from C and assume that their caller's stack frame is an interrupt frame. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-10 18:20:42 +08:00
memset(&current->thread.fp_state, 0, sizeof(current->thread.fp_state));
powerpc: Provide for giveup_fpu/altivec to save state in alternate location This provides a facility which is intended for use by KVM, where the contents of the FP/VSX and VMX (Altivec) registers can be saved away to somewhere other than the thread_struct when kernel code wants to use floating point or VMX instructions. This is done by providing a pointer in the thread_struct to indicate where the state should be saved to. The giveup_fpu() and giveup_altivec() functions test these pointers and save state to the indicated location if they are non-NULL. Note that the MSR_FP/VEC bits in task->thread.regs->msr are still used to indicate whether the CPU register state is live, even when an alternate save location is being used. This also provides load_fp_state() and load_vr_state() functions, which load up FP/VSX and VMX state from memory into the CPU registers, and corresponding store_fp_state() and store_vr_state() functions, which store FP/VSX and VMX state into memory from the CPU registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-10 18:21:10 +08:00
current->thread.fp_save_area = NULL;
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
#ifdef CONFIG_ALTIVEC
powerpc: Put FP/VSX and VR state into structures This creates new 'thread_fp_state' and 'thread_vr_state' structures to store FP/VSX state (including FPSCR) and Altivec/VSX state (including VSCR), and uses them in the thread_struct. In the thread_fp_state, the FPRs and VSRs are represented as u64 rather than double, since we rarely perform floating-point computations on the values, and this will enable the structures to be used in KVM code as well. Similarly FPSCR is now a u64 rather than a structure of two 32-bit values. This takes the offsets out of the macros such as SAVE_32FPRS, REST_32FPRS, etc. This enables the same macros to be used for normal and transactional state, enabling us to delete the transactional versions of the macros. This also removes the unused do_load_up_fpu and do_load_up_altivec, which were in fact buggy since they didn't create large enough stack frames to account for the fact that load_up_fpu and load_up_altivec are not designed to be called from C and assume that their caller's stack frame is an interrupt frame. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-10 18:20:42 +08:00
memset(&current->thread.vr_state, 0, sizeof(current->thread.vr_state));
current->thread.vr_state.vscr.u[3] = 0x00010000; /* Java mode disabled */
powerpc: Provide for giveup_fpu/altivec to save state in alternate location This provides a facility which is intended for use by KVM, where the contents of the FP/VSX and VMX (Altivec) registers can be saved away to somewhere other than the thread_struct when kernel code wants to use floating point or VMX instructions. This is done by providing a pointer in the thread_struct to indicate where the state should be saved to. The giveup_fpu() and giveup_altivec() functions test these pointers and save state to the indicated location if they are non-NULL. Note that the MSR_FP/VEC bits in task->thread.regs->msr are still used to indicate whether the CPU register state is live, even when an alternate save location is being used. This also provides load_fp_state() and load_vr_state() functions, which load up FP/VSX and VMX state from memory into the CPU registers, and corresponding store_fp_state() and store_vr_state() functions, which store FP/VSX and VMX state into memory from the CPU registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-10 18:21:10 +08:00
current->thread.vr_save_area = NULL;
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
current->thread.vrsave = 0;
current->thread.used_vr = 0;
#endif /* CONFIG_ALTIVEC */
#ifdef CONFIG_SPE
memset(current->thread.evr, 0, sizeof(current->thread.evr));
current->thread.acc = 0;
current->thread.spefscr = 0;
current->thread.used_spe = 0;
#endif /* CONFIG_SPE */
powerpc: Hook in new transactional memory code This hooks the new transactional memory code into context switching, FP/VMX/VMX unavailable and exception return. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-14 00:21:40 +08:00
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
current->thread.tm_tfhar = 0;
current->thread.tm_texasr = 0;
current->thread.tm_tfiar = 0;
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
}
powerpc: Move more symbol exports next to function definitions Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-08-20 06:00:02 +08:00
EXPORT_SYMBOL(start_thread);
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
#define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
| PR_FP_EXC_RES | PR_FP_EXC_INV)
int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
{
struct pt_regs *regs = tsk->thread.regs;
/* This is a bit hairy. If we are an SPE enabled processor
* (have embedded fp) we store the IEEE exception enable flags in
* fpexc_mode. fpexc_mode is also used for setting FP exception
* mode (asyn, precise, disabled) for 'Classic' FP. */
if (val & PR_FP_EXC_SW_ENABLE) {
#ifdef CONFIG_SPE
[POWERPC] Add cpu feature for SPE handling Make it so that SPE support can be determined at runtime. This is similiar to how we handle AltiVec. This allows us to have SPE support built in and work on processors with and without SPE. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-09-13 14:44:20 +08:00
if (cpu_has_feature(CPU_FTR_SPE)) {
powerpc: fix exception clearing in e500 SPE float emulation The e500 SPE floating-point emulation code clears existing exceptions (__FPU_FPSCR &= ~FP_EX_MASK;) before ORing in the exceptions from the emulated operation. However, these exception bits are the "sticky", cumulative exception bits, and should only be cleared by the user program setting SPEFSCR, not implicitly by any floating-point instruction (whether executed purely by the hardware or emulated). The spurious clearing of these bits shows up as missing exceptions in glibc testing. Fixing this, however, is not as simple as just not clearing the bits, because while the bits may be from previous floating-point operations (in which case they should not be cleared), the processor can also set the sticky bits itself before the interrupt for an exception occurs, and this can happen in cases when IEEE 754 semantics are that the sticky bit should not be set. Specifically, the "invalid" sticky bit is set in various cases with non-finite operands, where IEEE 754 semantics do not involve raising such an exception, and the "underflow" sticky bit is set in cases of exact underflow, whereas IEEE 754 semantics are that this flag is set only for inexact underflow. Thus, for correct emulation the kernel needs to know the setting of these two sticky bits before the instruction being emulated. When a floating-point operation raises an exception, the kernel can note the state of the sticky bits immediately afterwards. Some <fenv.h> functions that affect the state of these bits, such as fesetenv and feholdexcept, need to use prctl with PR_GET_FPEXC and PR_SET_FPEXC anyway, and so it is natural to record the state of those bits during that call into the kernel and so avoid any need for a separate call into the kernel to inform it of a change to those bits. Thus, the interface I chose to use (in this patch and the glibc port) is that one of those prctl calls must be made after any userspace change to those sticky bits, other than through a floating-point operation that traps into the kernel anyway. feclearexcept and fesetexceptflag duly make those calls, which would not be required were it not for this issue. The previous EGLIBC port, and the uClibc code copied from it, is fundamentally broken as regards any use of prctl for floating-point exceptions because it didn't use the PR_FP_EXC_SW_ENABLE bit in its prctl calls (and did various worse things, such as passing a pointer when prctl expected an integer). If you avoid anything where prctl is used, the clearing of sticky bits still means it will never give anything approximating correct exception semantics with existing kernels. I don't believe the patch makes things any worse for existing code that doesn't try to inform the kernel of changes to sticky bits - such code may get incorrect exceptions in some cases, but it would have done so anyway in other cases. Signed-off-by: Joseph Myers <joseph@codesourcery.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-12-11 07:07:45 +08:00
/*
* When the sticky exception bits are set
* directly by userspace, it must call prctl
* with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
* in the existing prctl settings) or
* PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
* the bits being set). <fenv.h> functions
* saving and restoring the whole
* floating-point environment need to do so
* anyway to restore the prctl settings from
* the saved environment.
*/
tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
[POWERPC] Add cpu feature for SPE handling Make it so that SPE support can be determined at runtime. This is similiar to how we handle AltiVec. This allows us to have SPE support built in and work on processors with and without SPE. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-09-13 14:44:20 +08:00
tsk->thread.fpexc_mode = val &
(PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
return 0;
} else {
return -EINVAL;
}
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
#else
return -EINVAL;
#endif
}
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
/* on a CONFIG_SPE this does not hurt us. The bits that
* __pack_fe01 use do not overlap with bits used for
* PR_FP_EXC_SW_ENABLE. Additionally, the MSR[FE0,FE1] bits
* on CONFIG_SPE implementations are reserved so writing to
* them does not change anything */
if (val > PR_FP_EXC_PRECISE)
return -EINVAL;
tsk->thread.fpexc_mode = __pack_fe01(val);
if (regs != NULL && (regs->msr & MSR_FP) != 0)
regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
| tsk->thread.fpexc_mode;
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
return 0;
}
int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
{
unsigned int val;
if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
#ifdef CONFIG_SPE
powerpc: fix exception clearing in e500 SPE float emulation The e500 SPE floating-point emulation code clears existing exceptions (__FPU_FPSCR &= ~FP_EX_MASK;) before ORing in the exceptions from the emulated operation. However, these exception bits are the "sticky", cumulative exception bits, and should only be cleared by the user program setting SPEFSCR, not implicitly by any floating-point instruction (whether executed purely by the hardware or emulated). The spurious clearing of these bits shows up as missing exceptions in glibc testing. Fixing this, however, is not as simple as just not clearing the bits, because while the bits may be from previous floating-point operations (in which case they should not be cleared), the processor can also set the sticky bits itself before the interrupt for an exception occurs, and this can happen in cases when IEEE 754 semantics are that the sticky bit should not be set. Specifically, the "invalid" sticky bit is set in various cases with non-finite operands, where IEEE 754 semantics do not involve raising such an exception, and the "underflow" sticky bit is set in cases of exact underflow, whereas IEEE 754 semantics are that this flag is set only for inexact underflow. Thus, for correct emulation the kernel needs to know the setting of these two sticky bits before the instruction being emulated. When a floating-point operation raises an exception, the kernel can note the state of the sticky bits immediately afterwards. Some <fenv.h> functions that affect the state of these bits, such as fesetenv and feholdexcept, need to use prctl with PR_GET_FPEXC and PR_SET_FPEXC anyway, and so it is natural to record the state of those bits during that call into the kernel and so avoid any need for a separate call into the kernel to inform it of a change to those bits. Thus, the interface I chose to use (in this patch and the glibc port) is that one of those prctl calls must be made after any userspace change to those sticky bits, other than through a floating-point operation that traps into the kernel anyway. feclearexcept and fesetexceptflag duly make those calls, which would not be required were it not for this issue. The previous EGLIBC port, and the uClibc code copied from it, is fundamentally broken as regards any use of prctl for floating-point exceptions because it didn't use the PR_FP_EXC_SW_ENABLE bit in its prctl calls (and did various worse things, such as passing a pointer when prctl expected an integer). If you avoid anything where prctl is used, the clearing of sticky bits still means it will never give anything approximating correct exception semantics with existing kernels. I don't believe the patch makes things any worse for existing code that doesn't try to inform the kernel of changes to sticky bits - such code may get incorrect exceptions in some cases, but it would have done so anyway in other cases. Signed-off-by: Joseph Myers <joseph@codesourcery.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-12-11 07:07:45 +08:00
if (cpu_has_feature(CPU_FTR_SPE)) {
/*
* When the sticky exception bits are set
* directly by userspace, it must call prctl
* with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
* in the existing prctl settings) or
* PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
* the bits being set). <fenv.h> functions
* saving and restoring the whole
* floating-point environment need to do so
* anyway to restore the prctl settings from
* the saved environment.
*/
tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
[POWERPC] Add cpu feature for SPE handling Make it so that SPE support can be determined at runtime. This is similiar to how we handle AltiVec. This allows us to have SPE support built in and work on processors with and without SPE. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-09-13 14:44:20 +08:00
val = tsk->thread.fpexc_mode;
powerpc: fix exception clearing in e500 SPE float emulation The e500 SPE floating-point emulation code clears existing exceptions (__FPU_FPSCR &= ~FP_EX_MASK;) before ORing in the exceptions from the emulated operation. However, these exception bits are the "sticky", cumulative exception bits, and should only be cleared by the user program setting SPEFSCR, not implicitly by any floating-point instruction (whether executed purely by the hardware or emulated). The spurious clearing of these bits shows up as missing exceptions in glibc testing. Fixing this, however, is not as simple as just not clearing the bits, because while the bits may be from previous floating-point operations (in which case they should not be cleared), the processor can also set the sticky bits itself before the interrupt for an exception occurs, and this can happen in cases when IEEE 754 semantics are that the sticky bit should not be set. Specifically, the "invalid" sticky bit is set in various cases with non-finite operands, where IEEE 754 semantics do not involve raising such an exception, and the "underflow" sticky bit is set in cases of exact underflow, whereas IEEE 754 semantics are that this flag is set only for inexact underflow. Thus, for correct emulation the kernel needs to know the setting of these two sticky bits before the instruction being emulated. When a floating-point operation raises an exception, the kernel can note the state of the sticky bits immediately afterwards. Some <fenv.h> functions that affect the state of these bits, such as fesetenv and feholdexcept, need to use prctl with PR_GET_FPEXC and PR_SET_FPEXC anyway, and so it is natural to record the state of those bits during that call into the kernel and so avoid any need for a separate call into the kernel to inform it of a change to those bits. Thus, the interface I chose to use (in this patch and the glibc port) is that one of those prctl calls must be made after any userspace change to those sticky bits, other than through a floating-point operation that traps into the kernel anyway. feclearexcept and fesetexceptflag duly make those calls, which would not be required were it not for this issue. The previous EGLIBC port, and the uClibc code copied from it, is fundamentally broken as regards any use of prctl for floating-point exceptions because it didn't use the PR_FP_EXC_SW_ENABLE bit in its prctl calls (and did various worse things, such as passing a pointer when prctl expected an integer). If you avoid anything where prctl is used, the clearing of sticky bits still means it will never give anything approximating correct exception semantics with existing kernels. I don't believe the patch makes things any worse for existing code that doesn't try to inform the kernel of changes to sticky bits - such code may get incorrect exceptions in some cases, but it would have done so anyway in other cases. Signed-off-by: Joseph Myers <joseph@codesourcery.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-12-11 07:07:45 +08:00
} else
[POWERPC] Add cpu feature for SPE handling Make it so that SPE support can be determined at runtime. This is similiar to how we handle AltiVec. This allows us to have SPE support built in and work on processors with and without SPE. Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-09-13 14:44:20 +08:00
return -EINVAL;
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
#else
return -EINVAL;
#endif
else
val = __unpack_fe01(tsk->thread.fpexc_mode);
return put_user(val, (unsigned int __user *) adr);
}
[PATCH] powerpc: Implement support for setting little-endian mode via prctl This adds the PowerPC part of the code to allow processes to change their endian mode via prctl. This also extends the alignment exception handler to be able to fix up alignment exceptions that occur in little-endian mode, both for "PowerPC" little-endian and true little-endian. We always enter signal handlers in big-endian mode -- the support for little-endian mode does not amount to the creation of a little-endian user/kernel ABI. If the signal handler returns, the endian mode is restored to what it was when the signal was delivered. We have two new kernel CPU feature bits, one for PPC little-endian and one for true little-endian. Most of the classic 32-bit processors support PPC little-endian, and this is reflected in the CPU feature table. There are two corresponding feature bits reported to userland in the AT_HWCAP aux vector entry. This is based on an earlier patch by Anton Blanchard. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-07 14:14:40 +08:00
int set_endian(struct task_struct *tsk, unsigned int val)
{
struct pt_regs *regs = tsk->thread.regs;
if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) ||
(val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE)))
return -EINVAL;
if (regs == NULL)
return -EINVAL;
if (val == PR_ENDIAN_BIG)
regs->msr &= ~MSR_LE;
else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
regs->msr |= MSR_LE;
else
return -EINVAL;
return 0;
}
int get_endian(struct task_struct *tsk, unsigned long adr)
{
struct pt_regs *regs = tsk->thread.regs;
unsigned int val;
if (!cpu_has_feature(CPU_FTR_PPC_LE) &&
!cpu_has_feature(CPU_FTR_REAL_LE))
return -EINVAL;
if (regs == NULL)
return -EINVAL;
if (regs->msr & MSR_LE) {
if (cpu_has_feature(CPU_FTR_REAL_LE))
val = PR_ENDIAN_LITTLE;
else
val = PR_ENDIAN_PPC_LITTLE;
} else
val = PR_ENDIAN_BIG;
return put_user(val, (unsigned int __user *)adr);
}
[PATCH] powerpc: Implement PR_[GS]ET_UNALIGN prctls for powerpc This gives the ability to control whether alignment exceptions get fixed up or reported to the process as a SIGBUS, using the existing PR_SET_UNALIGN and PR_GET_UNALIGN prctls. We do not implement the option of logging a message on alignment exceptions. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-07 14:15:39 +08:00
int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
{
tsk->thread.align_ctl = val;
return 0;
}
int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
{
return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
}
[POWERPC] Harden validate_sp against stack corruption If something has overflowed or corrupted the stack and causes an oops, and we try to print a stack trace, that will call validate_sp, which can itself cause an oops if the cpu field of the thread_info struct at the bottom of the stack has been corrupted (if CONFIG_IRQSTACKS is set). This makes debugging harder. To avoid the second oops, this adds a check to make sure that the cpu number is reasonable before using it to check whether the stack is on the softirq or hardirq stack. Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-02-19 08:42:42 +08:00
static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
unsigned long nbytes)
{
unsigned long stack_page;
unsigned long cpu = task_cpu(p);
/*
* Avoid crashing if the stack has overflowed and corrupted
* task_cpu(p), which is in the thread_info struct.
*/
if (cpu < NR_CPUS && cpu_possible(cpu)) {
stack_page = (unsigned long) hardirq_ctx[cpu];
if (sp >= stack_page + sizeof(struct thread_struct)
&& sp <= stack_page + THREAD_SIZE - nbytes)
return 1;
stack_page = (unsigned long) softirq_ctx[cpu];
if (sp >= stack_page + sizeof(struct thread_struct)
&& sp <= stack_page + THREAD_SIZE - nbytes)
return 1;
}
return 0;
}
[PATCH] powerpc: export validate_sp for oprofile calltrace Export validate_sp so we can use it in the oprofile calltrace code. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-27 08:46:18 +08:00
int validate_sp(unsigned long sp, struct task_struct *p,
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
unsigned long nbytes)
{
[PATCH] powerpc: task_stack_page() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 17:06:02 +08:00
unsigned long stack_page = (unsigned long)task_stack_page(p);
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
if (sp >= stack_page + sizeof(struct thread_struct)
&& sp <= stack_page + THREAD_SIZE - nbytes)
return 1;
[POWERPC] Harden validate_sp against stack corruption If something has overflowed or corrupted the stack and causes an oops, and we try to print a stack trace, that will call validate_sp, which can itself cause an oops if the cpu field of the thread_info struct at the bottom of the stack has been corrupted (if CONFIG_IRQSTACKS is set). This makes debugging harder. To avoid the second oops, this adds a check to make sure that the cpu number is reasonable before using it to check whether the stack is on the softirq or hardirq stack. Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-02-19 08:42:42 +08:00
return valid_irq_stack(sp, p, nbytes);
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
}
[PATCH] powerpc: export validate_sp for oprofile calltrace Export validate_sp so we can use it in the oprofile calltrace code. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-27 08:46:18 +08:00
EXPORT_SYMBOL(validate_sp);
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
unsigned long get_wchan(struct task_struct *p)
{
unsigned long ip, sp;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
sp = p->thread.ksp;
[POWERPC] Move stackframe definitions to common header This moves various definitions used all over the place to parse stack frames to ptrace.h so only one definition is needed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-17 12:34:59 +08:00
if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
return 0;
do {
sp = *(unsigned long *)sp;
[POWERPC] Move stackframe definitions to common header This moves various definitions used all over the place to parse stack frames to ptrace.h so only one definition is needed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-17 12:34:59 +08:00
if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
return 0;
if (count > 0) {
[POWERPC] Move stackframe definitions to common header This moves various definitions used all over the place to parse stack frames to ptrace.h so only one definition is needed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-17 12:34:59 +08:00
ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE];
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
if (!in_sched_functions(ip))
return ip;
}
} while (count++ < 16);
return 0;
}
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
powerpc: Allow the max stack trace depth to be configured On my screen, when something crashes, I only have space for maybe 16 functions of the stack trace before the information above it scrolls off the screen. It's easy to hack the kernel to print out only that much, but it's harder to remember to do it. This introduces a config option for it so that I can keep the setting in my config. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-11-20 11:24:07 +08:00
static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH;
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
void show_stack(struct task_struct *tsk, unsigned long *stack)
{
unsigned long sp, ip, lr, newsp;
int count = 0;
int firstframe = 1;
powerpc64: port of the function graph tracer This is a port of the function graph tracer that was written by Frederic Weisbecker for the x86. This only works for PPC64 at the moment and only for static tracing. PPC32 and dynamic function graph tracing support will come later. The trace produces a visual calling of functions: # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | 0) 2.224 us | } 0) ! 271.024 us | } 0) ! 320.080 us | } 0) ! 324.656 us | } 0) ! 329.136 us | } 0) | .put_prev_task_fair() { 0) | .update_curr() { 0) 2.240 us | .update_min_vruntime(); 0) 6.512 us | } 0) 2.528 us | .__enqueue_entity(); 0) + 15.536 us | } 0) | .pick_next_task_fair() { 0) 2.032 us | .__pick_next_entity(); 0) 2.064 us | .__clear_buddies(); 0) | .set_next_entity() { 0) 2.672 us | .__dequeue_entity(); 0) 6.864 us | } Geoff Lavand tested on PS3. Tested-by: Geoff Levand <geoffrey.levand@am.sony.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-10 13:10:27 +08:00
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
int curr_frame = current->curr_ret_stack;
extern void return_to_handler(void);
powerpc/ftrace: show real return addresses in modules When the function graph tracer is enabled, it replaces the return address with a hook back to the tracer. This makes back traces see the hook instead of the actual return address. The current code also shows the real address by checking if the return address jumps to the return_to_handler. If it is, is also prints out the saved real return address. On powerpc64, some modules may return to mod_return_to_handler, which is not checked. This patch will also show the real address if a return is to mod_return_to_handler as well. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-15 23:20:15 +08:00
unsigned long rth = (unsigned long)return_to_handler;
powerpc64: port of the function graph tracer This is a port of the function graph tracer that was written by Frederic Weisbecker for the x86. This only works for PPC64 at the moment and only for static tracing. PPC32 and dynamic function graph tracing support will come later. The trace produces a visual calling of functions: # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | 0) 2.224 us | } 0) ! 271.024 us | } 0) ! 320.080 us | } 0) ! 324.656 us | } 0) ! 329.136 us | } 0) | .put_prev_task_fair() { 0) | .update_curr() { 0) 2.240 us | .update_min_vruntime(); 0) 6.512 us | } 0) 2.528 us | .__enqueue_entity(); 0) + 15.536 us | } 0) | .pick_next_task_fair() { 0) 2.032 us | .__pick_next_entity(); 0) 2.064 us | .__clear_buddies(); 0) | .set_next_entity() { 0) 2.672 us | .__dequeue_entity(); 0) 6.864 us | } Geoff Lavand tested on PS3. Tested-by: Geoff Levand <geoffrey.levand@am.sony.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-10 13:10:27 +08:00
#endif
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
sp = (unsigned long) stack;
if (tsk == NULL)
tsk = current;
if (sp == 0) {
if (tsk == current)
powerpc: Rename __get_SP() to current_stack_pointer() Michael points out that __get_SP() is a pretty horrible function name. Let's give it a better name. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-13 16:41:39 +08:00
sp = current_stack_pointer();
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
else
sp = tsk->thread.ksp;
}
lr = 0;
printk("Call Trace:\n");
do {
[POWERPC] Move stackframe definitions to common header This moves various definitions used all over the place to parse stack frames to ptrace.h so only one definition is needed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-17 12:34:59 +08:00
if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
return;
stack = (unsigned long *) sp;
newsp = stack[0];
[POWERPC] Move stackframe definitions to common header This moves various definitions used all over the place to parse stack frames to ptrace.h so only one definition is needed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-17 12:34:59 +08:00
ip = stack[STACK_FRAME_LR_SAVE];
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
if (!firstframe || ip != lr) {
powerpc: Use new printk extension %pS to print symbols on oops This changes the oops and backtrace code to use the new %pS printk extension to print out symbols rather than manually calling print_symbol. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-07 11:44:31 +08:00
printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip);
powerpc64: port of the function graph tracer This is a port of the function graph tracer that was written by Frederic Weisbecker for the x86. This only works for PPC64 at the moment and only for static tracing. PPC32 and dynamic function graph tracing support will come later. The trace produces a visual calling of functions: # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | 0) 2.224 us | } 0) ! 271.024 us | } 0) ! 320.080 us | } 0) ! 324.656 us | } 0) ! 329.136 us | } 0) | .put_prev_task_fair() { 0) | .update_curr() { 0) 2.240 us | .update_min_vruntime(); 0) 6.512 us | } 0) 2.528 us | .__enqueue_entity(); 0) + 15.536 us | } 0) | .pick_next_task_fair() { 0) 2.032 us | .__pick_next_entity(); 0) 2.064 us | .__clear_buddies(); 0) | .set_next_entity() { 0) 2.672 us | .__dequeue_entity(); 0) 6.864 us | } Geoff Lavand tested on PS3. Tested-by: Geoff Levand <geoffrey.levand@am.sony.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-10 13:10:27 +08:00
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
powerpc/ftrace: Remove mod_return_to_handler mod_return_to_handler is the same as return_to_handler, except it handles the change of the TOC (r2). Add this into return_to_handler and remove mod_return_to_handler. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-09-17 15:07:03 +08:00
if ((ip == rth) && curr_frame >= 0) {
powerpc/oops: Fix missing pr_cont()s in show_stack() Previously we got away with printing the stack trace in multiple pieces and it usually looked right. But since commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing continuation lines"), KERN_CONT is now required when printing continuation lines. Use pr_cont() as appropriate. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-02 19:20:46 +08:00
pr_cont(" (%pS)",
powerpc64: port of the function graph tracer This is a port of the function graph tracer that was written by Frederic Weisbecker for the x86. This only works for PPC64 at the moment and only for static tracing. PPC32 and dynamic function graph tracing support will come later. The trace produces a visual calling of functions: # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | 0) 2.224 us | } 0) ! 271.024 us | } 0) ! 320.080 us | } 0) ! 324.656 us | } 0) ! 329.136 us | } 0) | .put_prev_task_fair() { 0) | .update_curr() { 0) 2.240 us | .update_min_vruntime(); 0) 6.512 us | } 0) 2.528 us | .__enqueue_entity(); 0) + 15.536 us | } 0) | .pick_next_task_fair() { 0) 2.032 us | .__pick_next_entity(); 0) 2.064 us | .__clear_buddies(); 0) | .set_next_entity() { 0) 2.672 us | .__dequeue_entity(); 0) 6.864 us | } Geoff Lavand tested on PS3. Tested-by: Geoff Levand <geoffrey.levand@am.sony.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-10 13:10:27 +08:00
(void *)current->ret_stack[curr_frame].ret);
curr_frame--;
}
#endif
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
if (firstframe)
powerpc/oops: Fix missing pr_cont()s in show_stack() Previously we got away with printing the stack trace in multiple pieces and it usually looked right. But since commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing continuation lines"), KERN_CONT is now required when printing continuation lines. Use pr_cont() as appropriate. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-02 19:20:46 +08:00
pr_cont(" (unreliable)");
pr_cont("\n");
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
}
firstframe = 0;
/*
* See if this is an exception frame.
* We look for the "regshere" marker in the current frame.
*/
[POWERPC] Move stackframe definitions to common header This moves various definitions used all over the place to parse stack frames to ptrace.h so only one definition is needed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-17 12:34:59 +08:00
if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE)
&& stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
struct pt_regs *regs = (struct pt_regs *)
(sp + STACK_FRAME_OVERHEAD);
lr = regs->link;
powerpc: Reduce scariness of interrupt frames in stack traces Some people see things like "Exception: 501" in stack traces in dmesg and assume that means that something has gone badly wrong, when in fact "Exception: 501" just means a device interrupt was taken. This changes "Exception" to "interrupt" to make it clearer that we are just recording the fact of a change in control flow rather than some error condition. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-06-12 14:53:08 +08:00
printk("--- interrupt: %lx at %pS\n LR = %pS\n",
powerpc: Use new printk extension %pS to print symbols on oops This changes the oops and backtrace code to use the new %pS printk extension to print out symbols rather than manually calling print_symbol. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-07 11:44:31 +08:00
regs->trap, (void *)regs->nip, (void *)lr);
powerpc: make process.c suitable for both 32-bit and 64-bit Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:29:05 +08:00
firstframe = 1;
}
sp = newsp;
} while (count++ < kstack_depth_to_print);
}
[PATCH] powerpc: Fix runlatch performance issues The runlatch SPR can take a lot of time to write. My original runlatch code would set it on every exception entry even though most of the time this was not required. It would also continually set it in the idle loop, which is an issue on an SMT capable processor. Now we cache the runlatch value in a threadinfo bit, and only check for it in decrementer and hardware interrupt exceptions as well as the idle loop. Boot on POWER3, POWER5 and iseries, and compile tested on pmac32. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-13 11:48:35 +08:00
#ifdef CONFIG_PPC64
powerpc: Rework runlatch code This moves the inlines into system.h and changes the runlatch code to use the thread local flags (non-atomic) rather than the TIF flags (atomic) to keep track of the latch state. The code to turn it back on in an asynchronous interrupt is now simplified and partially inlined. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-03-01 09:45:27 +08:00
/* Called with hard IRQs off */
powerpc: Fix stack overflow crash in resume_kernel when ftracing It's possible for us to crash when running with ftrace enabled, eg: Bad kernel stack pointer bffffd12 at c00000000000a454 cpu 0x3: Vector: 300 (Data Access) at [c00000000ffe3d40] pc: c00000000000a454: resume_kernel+0x34/0x60 lr: c00000000000335c: performance_monitor_common+0x15c/0x180 sp: bffffd12 msr: 8000000000001032 dar: bffffd12 dsisr: 42000000 If we look at current's stack (paca->__current->stack) we see it is equal to c0000002ecab0000. Our stack is 16K, and comparing to paca->kstack (c0000002ecab3e30) we can see that we have overflowed our kernel stack. This leads to us writing over our struct thread_info, and in this case we have corrupted thread_info->flags and set _TIF_EMULATE_STACK_STORE. Dumping the stack we see: 3:mon> t c0000002ecab0000 [c0000002ecab0000] c00000000002131c .performance_monitor_exception+0x5c/0x70 [c0000002ecab0080] c00000000000335c performance_monitor_common+0x15c/0x180 --- Exception: f01 (Performance Monitor) at c0000000000fb2ec .trace_hardirqs_off+0x1c/0x30 [c0000002ecab0370] c00000000016fdb0 .trace_graph_entry+0xb0/0x280 (unreliable) [c0000002ecab0410] c00000000003d038 .prepare_ftrace_return+0x98/0x130 [c0000002ecab04b0] c00000000000a920 .ftrace_graph_caller+0x14/0x28 [c0000002ecab0520] c0000000000d6b58 .idle_cpu+0x18/0x90 [c0000002ecab05a0] c00000000000a934 .return_to_handler+0x0/0x34 [c0000002ecab0620] c00000000001e660 .timer_interrupt+0x160/0x300 [c0000002ecab06d0] c0000000000025dc decrementer_common+0x15c/0x180 --- Exception: 901 (Decrementer) at c0000000000104d4 .arch_local_irq_restore+0x74/0xa0 [c0000002ecab09c0] c0000000000fe044 .trace_hardirqs_on+0x14/0x30 (unreliable) [c0000002ecab0fb0] c00000000016fe3c .trace_graph_entry+0x13c/0x280 [c0000002ecab1050] c00000000003d038 .prepare_ftrace_return+0x98/0x130 [c0000002ecab10f0] c00000000000a920 .ftrace_graph_caller+0x14/0x28 [c0000002ecab1160] c0000000000161f0 .__ppc64_runlatch_on+0x10/0x40 [c0000002ecab11d0] c00000000000a934 .return_to_handler+0x0/0x34 --- Exception: 901 (Decrementer) at c0000000000104d4 .arch_local_irq_restore+0x74/0xa0 ... and so on __ppc64_runlatch_on() is called from RUNLATCH_ON in the exception entry path. At that point the irq state is not consistent, ie. interrupts are hard disabled (by the exception entry), but the paca soft-enabled flag may be out of sync. This leads to the local_irq_restore() in trace_graph_entry() actually enabling interrupts, which we do not want. Because we have not yet reprogrammed the decrementer we immediately take another decrementer exception, and recurse. The fix is twofold. Firstly make sure we call DISABLE_INTS before calling RUNLATCH_ON. The badly named DISABLE_INTS actually reconciles the irq state in the paca with the hardware, making it safe again to call local_irq_save/restore(). Although that should be sufficient to fix the bug, we also mark the runlatch routines as notrace. They are called very early in the exception entry and we are asking for trouble tracing them. They are also fairly uninteresting and tracing them just adds unnecessary overhead. [ This regression was introduced by fe1952fc0afb9a2e4c79f103c08aef5d13db1873 "powerpc: Rework runlatch code" by myself --BenH ] CC: <stable@vger.kernel.org> [v3.4+] Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-13 19:04:56 +08:00
void notrace __ppc64_runlatch_on(void)
[PATCH] powerpc: Fix runlatch performance issues The runlatch SPR can take a lot of time to write. My original runlatch code would set it on every exception entry even though most of the time this was not required. It would also continually set it in the idle loop, which is an issue on an SMT capable processor. Now we cache the runlatch value in a threadinfo bit, and only check for it in decrementer and hardware interrupt exceptions as well as the idle loop. Boot on POWER3, POWER5 and iseries, and compile tested on pmac32. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-13 11:48:35 +08:00
{
powerpc: Rework runlatch code This moves the inlines into system.h and changes the runlatch code to use the thread local flags (non-atomic) rather than the TIF flags (atomic) to keep track of the latch state. The code to turn it back on in an asynchronous interrupt is now simplified and partially inlined. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-03-01 09:45:27 +08:00
struct thread_info *ti = current_thread_info();
[PATCH] powerpc: Fix runlatch performance issues The runlatch SPR can take a lot of time to write. My original runlatch code would set it on every exception entry even though most of the time this was not required. It would also continually set it in the idle loop, which is an issue on an SMT capable processor. Now we cache the runlatch value in a threadinfo bit, and only check for it in decrementer and hardware interrupt exceptions as well as the idle loop. Boot on POWER3, POWER5 and iseries, and compile tested on pmac32. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-13 11:48:35 +08:00
unsigned long ctrl;
powerpc: Rework runlatch code This moves the inlines into system.h and changes the runlatch code to use the thread local flags (non-atomic) rather than the TIF flags (atomic) to keep track of the latch state. The code to turn it back on in an asynchronous interrupt is now simplified and partially inlined. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-03-01 09:45:27 +08:00
ctrl = mfspr(SPRN_CTRLF);
ctrl |= CTRL_RUNLATCH;
mtspr(SPRN_CTRLT, ctrl);
[PATCH] powerpc: Fix runlatch performance issues The runlatch SPR can take a lot of time to write. My original runlatch code would set it on every exception entry even though most of the time this was not required. It would also continually set it in the idle loop, which is an issue on an SMT capable processor. Now we cache the runlatch value in a threadinfo bit, and only check for it in decrementer and hardware interrupt exceptions as well as the idle loop. Boot on POWER3, POWER5 and iseries, and compile tested on pmac32. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-13 11:48:35 +08:00
powerpc: Fix typo in runlatch code Commit fe1952fc0afb9a2e4c79f103c08aef5d13db1873 "powerpc: Rework runlatch code" has a nasty typo where it uses "TLF_RUNLATCH" instead of "_TLF_RUNLATCH" (bit number instead of bit mask), causing some flags to be potentially lost such as _TLF_RESTORE_SIGMASK (Brown paper bag for me ! We should be able to make that break at compile time with a bit of magic, any volunteer ?) Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-04-11 08:42:15 +08:00
ti->local_flags |= _TLF_RUNLATCH;
[PATCH] powerpc: Fix runlatch performance issues The runlatch SPR can take a lot of time to write. My original runlatch code would set it on every exception entry even though most of the time this was not required. It would also continually set it in the idle loop, which is an issue on an SMT capable processor. Now we cache the runlatch value in a threadinfo bit, and only check for it in decrementer and hardware interrupt exceptions as well as the idle loop. Boot on POWER3, POWER5 and iseries, and compile tested on pmac32. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-13 11:48:35 +08:00
}
powerpc: Rework runlatch code This moves the inlines into system.h and changes the runlatch code to use the thread local flags (non-atomic) rather than the TIF flags (atomic) to keep track of the latch state. The code to turn it back on in an asynchronous interrupt is now simplified and partially inlined. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-03-01 09:45:27 +08:00
/* Called with hard IRQs off */
powerpc: Fix stack overflow crash in resume_kernel when ftracing It's possible for us to crash when running with ftrace enabled, eg: Bad kernel stack pointer bffffd12 at c00000000000a454 cpu 0x3: Vector: 300 (Data Access) at [c00000000ffe3d40] pc: c00000000000a454: resume_kernel+0x34/0x60 lr: c00000000000335c: performance_monitor_common+0x15c/0x180 sp: bffffd12 msr: 8000000000001032 dar: bffffd12 dsisr: 42000000 If we look at current's stack (paca->__current->stack) we see it is equal to c0000002ecab0000. Our stack is 16K, and comparing to paca->kstack (c0000002ecab3e30) we can see that we have overflowed our kernel stack. This leads to us writing over our struct thread_info, and in this case we have corrupted thread_info->flags and set _TIF_EMULATE_STACK_STORE. Dumping the stack we see: 3:mon> t c0000002ecab0000 [c0000002ecab0000] c00000000002131c .performance_monitor_exception+0x5c/0x70 [c0000002ecab0080] c00000000000335c performance_monitor_common+0x15c/0x180 --- Exception: f01 (Performance Monitor) at c0000000000fb2ec .trace_hardirqs_off+0x1c/0x30 [c0000002ecab0370] c00000000016fdb0 .trace_graph_entry+0xb0/0x280 (unreliable) [c0000002ecab0410] c00000000003d038 .prepare_ftrace_return+0x98/0x130 [c0000002ecab04b0] c00000000000a920 .ftrace_graph_caller+0x14/0x28 [c0000002ecab0520] c0000000000d6b58 .idle_cpu+0x18/0x90 [c0000002ecab05a0] c00000000000a934 .return_to_handler+0x0/0x34 [c0000002ecab0620] c00000000001e660 .timer_interrupt+0x160/0x300 [c0000002ecab06d0] c0000000000025dc decrementer_common+0x15c/0x180 --- Exception: 901 (Decrementer) at c0000000000104d4 .arch_local_irq_restore+0x74/0xa0 [c0000002ecab09c0] c0000000000fe044 .trace_hardirqs_on+0x14/0x30 (unreliable) [c0000002ecab0fb0] c00000000016fe3c .trace_graph_entry+0x13c/0x280 [c0000002ecab1050] c00000000003d038 .prepare_ftrace_return+0x98/0x130 [c0000002ecab10f0] c00000000000a920 .ftrace_graph_caller+0x14/0x28 [c0000002ecab1160] c0000000000161f0 .__ppc64_runlatch_on+0x10/0x40 [c0000002ecab11d0] c00000000000a934 .return_to_handler+0x0/0x34 --- Exception: 901 (Decrementer) at c0000000000104d4 .arch_local_irq_restore+0x74/0xa0 ... and so on __ppc64_runlatch_on() is called from RUNLATCH_ON in the exception entry path. At that point the irq state is not consistent, ie. interrupts are hard disabled (by the exception entry), but the paca soft-enabled flag may be out of sync. This leads to the local_irq_restore() in trace_graph_entry() actually enabling interrupts, which we do not want. Because we have not yet reprogrammed the decrementer we immediately take another decrementer exception, and recurse. The fix is twofold. Firstly make sure we call DISABLE_INTS before calling RUNLATCH_ON. The badly named DISABLE_INTS actually reconciles the irq state in the paca with the hardware, making it safe again to call local_irq_save/restore(). Although that should be sufficient to fix the bug, we also mark the runlatch routines as notrace. They are called very early in the exception entry and we are asking for trouble tracing them. They are also fairly uninteresting and tracing them just adds unnecessary overhead. [ This regression was introduced by fe1952fc0afb9a2e4c79f103c08aef5d13db1873 "powerpc: Rework runlatch code" by myself --BenH ] CC: <stable@vger.kernel.org> [v3.4+] Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-13 19:04:56 +08:00
void notrace __ppc64_runlatch_off(void)
[PATCH] powerpc: Fix runlatch performance issues The runlatch SPR can take a lot of time to write. My original runlatch code would set it on every exception entry even though most of the time this was not required. It would also continually set it in the idle loop, which is an issue on an SMT capable processor. Now we cache the runlatch value in a threadinfo bit, and only check for it in decrementer and hardware interrupt exceptions as well as the idle loop. Boot on POWER3, POWER5 and iseries, and compile tested on pmac32. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-13 11:48:35 +08:00
{
powerpc: Rework runlatch code This moves the inlines into system.h and changes the runlatch code to use the thread local flags (non-atomic) rather than the TIF flags (atomic) to keep track of the latch state. The code to turn it back on in an asynchronous interrupt is now simplified and partially inlined. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-03-01 09:45:27 +08:00
struct thread_info *ti = current_thread_info();
[PATCH] powerpc: Fix runlatch performance issues The runlatch SPR can take a lot of time to write. My original runlatch code would set it on every exception entry even though most of the time this was not required. It would also continually set it in the idle loop, which is an issue on an SMT capable processor. Now we cache the runlatch value in a threadinfo bit, and only check for it in decrementer and hardware interrupt exceptions as well as the idle loop. Boot on POWER3, POWER5 and iseries, and compile tested on pmac32. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-13 11:48:35 +08:00
unsigned long ctrl;
powerpc: Fix typo in runlatch code Commit fe1952fc0afb9a2e4c79f103c08aef5d13db1873 "powerpc: Rework runlatch code" has a nasty typo where it uses "TLF_RUNLATCH" instead of "_TLF_RUNLATCH" (bit number instead of bit mask), causing some flags to be potentially lost such as _TLF_RESTORE_SIGMASK (Brown paper bag for me ! We should be able to make that break at compile time with a bit of magic, any volunteer ?) Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-04-11 08:42:15 +08:00
ti->local_flags &= ~_TLF_RUNLATCH;
[PATCH] powerpc: Fix runlatch performance issues The runlatch SPR can take a lot of time to write. My original runlatch code would set it on every exception entry even though most of the time this was not required. It would also continually set it in the idle loop, which is an issue on an SMT capable processor. Now we cache the runlatch value in a threadinfo bit, and only check for it in decrementer and hardware interrupt exceptions as well as the idle loop. Boot on POWER3, POWER5 and iseries, and compile tested on pmac32. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-13 11:48:35 +08:00
powerpc: Inline ppc64_runlatch_off I'm sick of seeing ppc64_runlatch_off in our profiles, so inline it into the callers. To avoid a mess of circular includes I didn't add it as an inline function. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-08-06 11:28:19 +08:00
ctrl = mfspr(SPRN_CTRLF);
ctrl &= ~CTRL_RUNLATCH;
mtspr(SPRN_CTRLT, ctrl);
[PATCH] powerpc: Fix runlatch performance issues The runlatch SPR can take a lot of time to write. My original runlatch code would set it on every exception entry even though most of the time this was not required. It would also continually set it in the idle loop, which is an issue on an SMT capable processor. Now we cache the runlatch value in a threadinfo bit, and only check for it in decrementer and hardware interrupt exceptions as well as the idle loop. Boot on POWER3, POWER5 and iseries, and compile tested on pmac32. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-13 11:48:35 +08:00
}
powerpc: Rework runlatch code This moves the inlines into system.h and changes the runlatch code to use the thread local flags (non-atomic) rather than the TIF flags (atomic) to keep track of the latch state. The code to turn it back on in an asynchronous interrupt is now simplified and partially inlined. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-03-01 09:45:27 +08:00
#endif /* CONFIG_PPC64 */
[POWERPC] Fix kernel stack allocation alignment The powerpc kernel stacks need to be naturally aligned, as they contain the thread info at the bottom, which is obtained by clearing the low bits of the stack pointer. However, when using 64K pages, the stack is smaller than a page, so we use kmalloc to allocate it, but that doesn't provide the alignment guarantee we need. It appeared to work so far... until one enables SLUB debugging which then returns unaligned pointers. Ooops... This fixes it by using a slab cache with enforced alignment. It relies on my previous patch that adds a thread_info_cache_init() callback. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-18 14:56:17 +08:00
powerpc: Randomise lower bits of stack address Randomise the lower bits of the stack address. More randomisation is good for security but the scatter can also help with SMT threads that share an L1. A quick test case shows this working: int main() { int sp; printf("%x\n", (unsigned long)&sp & 4095); } before: 80 80 80 80 80 after: 610 490 300 6b0 d80 Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-22 09:50:03 +08:00
unsigned long arch_align_stack(unsigned long sp)
{
if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
sp -= get_random_int() & ~PAGE_MASK;
return sp & ~0xf;
}
powerpc: Randomise the brk region Randomize the heap. before: tundro2:~ # sleep 1 & cat /proc/${!}/maps | grep heap 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] after tundro2:~ # sleep 1 & cat /proc/${!}/maps | grep heap 19419000-1951a000 rw-p 19419000 00:00 0 [heap] 325ff000-32700000 rw-p 325ff000 00:00 0 [heap] 1a97c000-1aa7d000 rw-p 1a97c000 00:00 0 [heap] 1cc60000-1cd61000 rw-p 1cc60000 00:00 0 [heap] 1afa9000-1b0aa000 rw-p 1afa9000 00:00 0 [heap] Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-22 09:50:04 +08:00
static inline unsigned long brk_rnd(void)
{
unsigned long rnd = 0;
/* 8MB for 32bit, 1GB for 64bit */
if (is_32bit_task())
mm: ASLR: use get_random_long() Replace calls to get_random_int() followed by a cast to (unsigned long) with calls to get_random_long(). Also address shifting bug which, in case of x86 removed entropy mask for mmap_rnd_bits values > 31 bits. Signed-off-by: Daniel Cashman <dcashman@android.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: David S. Miller <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Nick Kralevich <nnk@google.com> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Mark Salyzyn <salyzyn@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-27 07:19:37 +08:00
rnd = (get_random_long() % (1UL<<(23-PAGE_SHIFT)));
powerpc: Randomise the brk region Randomize the heap. before: tundro2:~ # sleep 1 & cat /proc/${!}/maps | grep heap 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] after tundro2:~ # sleep 1 & cat /proc/${!}/maps | grep heap 19419000-1951a000 rw-p 19419000 00:00 0 [heap] 325ff000-32700000 rw-p 325ff000 00:00 0 [heap] 1a97c000-1aa7d000 rw-p 1a97c000 00:00 0 [heap] 1cc60000-1cd61000 rw-p 1cc60000 00:00 0 [heap] 1afa9000-1b0aa000 rw-p 1afa9000 00:00 0 [heap] Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-22 09:50:04 +08:00
else
mm: ASLR: use get_random_long() Replace calls to get_random_int() followed by a cast to (unsigned long) with calls to get_random_long(). Also address shifting bug which, in case of x86 removed entropy mask for mmap_rnd_bits values > 31 bits. Signed-off-by: Daniel Cashman <dcashman@android.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: David S. Miller <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Nick Kralevich <nnk@google.com> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Mark Salyzyn <salyzyn@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-27 07:19:37 +08:00
rnd = (get_random_long() % (1UL<<(30-PAGE_SHIFT)));
powerpc: Randomise the brk region Randomize the heap. before: tundro2:~ # sleep 1 & cat /proc/${!}/maps | grep heap 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] after tundro2:~ # sleep 1 & cat /proc/${!}/maps | grep heap 19419000-1951a000 rw-p 19419000 00:00 0 [heap] 325ff000-32700000 rw-p 325ff000 00:00 0 [heap] 1a97c000-1aa7d000 rw-p 1a97c000 00:00 0 [heap] 1cc60000-1cd61000 rw-p 1cc60000 00:00 0 [heap] 1afa9000-1b0aa000 rw-p 1afa9000 00:00 0 [heap] Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-22 09:50:04 +08:00
return rnd << PAGE_SHIFT;
}
unsigned long arch_randomize_brk(struct mm_struct *mm)
{
powerpc: Move 64bit heap above 1TB on machines with 1TB segments If we are using 1TB segments and we are allowed to randomise the heap, we can put it above 1TB so it is backed by a 1TB segment. Otherwise the heap will be in the bottom 1TB which always uses 256MB segments and this may result in a performance penalty. This functionality is disabled when heap randomisation is turned off: echo 1 > /proc/sys/kernel/randomize_va_space which may be useful when trying to allocate the maximum amount of 16M or 16G pages. On a microbenchmark that repeatedly touches 32GB of memory with a stride of 256MB + 4kB (designed to stress 256MB segments while still mapping nicely into the L1 cache), we see the improvement: Force malloc to use heap all the time: # export MALLOC_MMAP_MAX_=0 MALLOC_TRIM_THRESHOLD_=-1 Disable heap randomization: # echo 1 > /proc/sys/kernel/randomize_va_space # time ./test 12.51s Enable heap randomization: # echo 2 > /proc/sys/kernel/randomize_va_space # time ./test 1.70s Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-09-22 00:52:35 +08:00
unsigned long base = mm->brk;
unsigned long ret;
powerpc: Fix compile errors found by new ppc64e_defconfig Fix the following 3 issues: arch/powerpc/kernel/process.c: In function 'arch_randomize_brk': arch/powerpc/kernel/process.c:1183: error: 'mmu_highuser_ssize' undeclared (first use in this function) arch/powerpc/kernel/process.c:1183: error: (Each undeclared identifier is reported only once arch/powerpc/kernel/process.c:1183: error: for each function it appears in.) arch/powerpc/kernel/process.c:1183: error: 'MMU_SEGSIZE_1T' undeclared (first use in this function) In file included from arch/powerpc/kernel/setup_64.c:60: arch/powerpc/include/asm/mmu-hash64.h:132: error: redefinition of 'struct mmu_psize_def' arch/powerpc/include/asm/mmu-hash64.h:159: error: expected identifier or '(' before numeric constant arch/powerpc/include/asm/mmu-hash64.h:396: error: conflicting types for 'mm_context_t' arch/powerpc/include/asm/mmu-book3e.h:184: error: previous declaration of 'mm_context_t' was here cc1: warnings being treated as errors arch/powerpc/kernel/pci_64.c: In function 'pcibios_unmap_io_space': arch/powerpc/kernel/pci_64.c:100: error: unused variable 'res' Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-10-16 15:05:17 +08:00
#ifdef CONFIG_PPC_STD_MMU_64
powerpc: Move 64bit heap above 1TB on machines with 1TB segments If we are using 1TB segments and we are allowed to randomise the heap, we can put it above 1TB so it is backed by a 1TB segment. Otherwise the heap will be in the bottom 1TB which always uses 256MB segments and this may result in a performance penalty. This functionality is disabled when heap randomisation is turned off: echo 1 > /proc/sys/kernel/randomize_va_space which may be useful when trying to allocate the maximum amount of 16M or 16G pages. On a microbenchmark that repeatedly touches 32GB of memory with a stride of 256MB + 4kB (designed to stress 256MB segments while still mapping nicely into the L1 cache), we see the improvement: Force malloc to use heap all the time: # export MALLOC_MMAP_MAX_=0 MALLOC_TRIM_THRESHOLD_=-1 Disable heap randomization: # echo 1 > /proc/sys/kernel/randomize_va_space # time ./test 12.51s Enable heap randomization: # echo 2 > /proc/sys/kernel/randomize_va_space # time ./test 1.70s Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-09-22 00:52:35 +08:00
/*
* If we are using 1TB segments and we are allowed to randomise
* the heap, we can put it above 1TB so it is backed by a 1TB
* segment. Otherwise the heap will be in the bottom 1TB
* which always uses 256MB segments and this may result in a
powerpc/mm/radix: Use STD_MMU_64 to properly isolate hash related code We also use MMU_FTR_RADIX to branch out from code path specific to hash. No functionality change. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-29 21:26:07 +08:00
* performance penalty. We don't need to worry about radix. For
* radix, mmu_highuser_ssize remains unchanged from 256MB.
powerpc: Move 64bit heap above 1TB on machines with 1TB segments If we are using 1TB segments and we are allowed to randomise the heap, we can put it above 1TB so it is backed by a 1TB segment. Otherwise the heap will be in the bottom 1TB which always uses 256MB segments and this may result in a performance penalty. This functionality is disabled when heap randomisation is turned off: echo 1 > /proc/sys/kernel/randomize_va_space which may be useful when trying to allocate the maximum amount of 16M or 16G pages. On a microbenchmark that repeatedly touches 32GB of memory with a stride of 256MB + 4kB (designed to stress 256MB segments while still mapping nicely into the L1 cache), we see the improvement: Force malloc to use heap all the time: # export MALLOC_MMAP_MAX_=0 MALLOC_TRIM_THRESHOLD_=-1 Disable heap randomization: # echo 1 > /proc/sys/kernel/randomize_va_space # time ./test 12.51s Enable heap randomization: # echo 2 > /proc/sys/kernel/randomize_va_space # time ./test 1.70s Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-09-22 00:52:35 +08:00
*/
if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T))
base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T);
#endif
ret = PAGE_ALIGN(base + brk_rnd());
powerpc: Randomise the brk region Randomize the heap. before: tundro2:~ # sleep 1 & cat /proc/${!}/maps | grep heap 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] 10017000-10118000 rw-p 10017000 00:00 0 [heap] after tundro2:~ # sleep 1 & cat /proc/${!}/maps | grep heap 19419000-1951a000 rw-p 19419000 00:00 0 [heap] 325ff000-32700000 rw-p 325ff000 00:00 0 [heap] 1a97c000-1aa7d000 rw-p 1a97c000 00:00 0 [heap] 1cc60000-1cd61000 rw-p 1cc60000 00:00 0 [heap] 1afa9000-1b0aa000 rw-p 1afa9000 00:00 0 [heap] Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-22 09:50:04 +08:00
if (ret < mm->brk)
return mm->brk;
return ret;
}
powerpc: Randomise PIEs Randomise ELF_ET_DYN_BASE, which is used when loading position independent executables. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-22 09:50:07 +08:00