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linux/arch/mips/kernel/r2300_switch.S

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Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
/*
* r2300_switch.S: R2300 specific task switching code.
*
* Copyright (C) 1994, 1995, 1996, 1999 by Ralf Baechle
* Copyright (C) 1994, 1995, 1996 by Andreas Busse
*
* Multi-cpu abstraction and macros for easier reading:
update David Miller's old email address Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-04-05 05:15:29 +08:00
* Copyright (C) 1996 David S. Miller (davem@davemloft.net)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
*
* Further modifications to make this work:
* Copyright (c) 1998-2000 Harald Koerfgen
*/
#include <asm/asm.h>
#include <asm/cachectl.h>
#include <asm/fpregdef.h>
#include <asm/mipsregs.h>
kbuild: mips use generic asm-offsets.h support Removed obsolete stuff from arch makefile. mips had a special rule for generating asm-offsets.h so preserved it using an architecture specific hook in top-level Kbuild file. Renamed .h file to asm-offsets.h Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-09-10 04:32:31 +08:00
#include <asm/asm-offsets.h>
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
#include <asm/regdef.h>
#include <asm/stackframe.h>
#include <asm/thread_info.h>
#include <asm/asmmacro.h>
.set mips1
.align 5
/*
* Offset to the current process status flags, the first 32 bytes of the
* stack are not used.
*/
#define ST_OFF (_THREAD_SIZE - 32 - PT_SIZE + PT_STATUS)
/*
* task_struct *resume(task_struct *prev, task_struct *next,
MIPS: Fix R2300 FP context switch handling Commit 1a3d59579b9f ("MIPS: Tidy up FPU context switching") removed FP context saving from the asm-written resume function in favour of reusing existing code to perform the same task. However it only removed the FP context saving code from the r4k_switch.S implementation of resume. Remove it from the r2300_switch.S implementation too in order to prevent attempting to save the FP context twice, which would likely lead to an exception from the second save because the FPU had already been disabled by the first save. This patch has only been build tested, using rbtx49xx_defconfig. Fixes: 1a3d59579b9f ("MIPS: Tidy up FPU context switching") Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-kernel@vger.kernel.org Cc: Manuel Lauss <manuel.lauss@gmail.com> Patchwork: https://patchwork.linux-mips.org/patch/11167/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-22 01:07:42 +08:00
* struct thread_info *next_ti)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
*/
LEAF(resume)
[MIPS] Disallow CpU exception in kernel again. The commit 4d40bff7110e9e1a97ff8c01bdd6350e9867cc10 ("Allow CpU exception in kernel partially") was broken. The commit was to fix theoretical problem but broke usual case. Revert it for now. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-04-14 01:37:26 +08:00
mfc0 t1, CP0_STATUS
sw t1, THREAD_STATUS(a0)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
cpu_save_nonscratch a0
sw ra, THREAD_REG31(a0)
MIPS: r4k,octeon,r2300: stack protector: change canary per task For non-SMP, uses the new random canary value that is stored in the task struct whenever a new task is forked. Based on ARM version in df0698be14c6683606d5df2d83e3ae40f85ed0d9 and subject to the same limitations: the variable GCC expects, __stack_chk_guard, is global, so this will not work on SMP. Quoting Nicolas Pitre <nico@fluxnic.net>: "One way to overcome this GCC limitation would be to locate the __stack_chk_guard variable into a memory page of its own for each CPU, and then use TLB locking to have each CPU see its own page at the same virtual address for each of them." Signed-off-by: Gregory Fong <gregory.0xf0@gmail.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5488/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-06-18 03:36:07 +08:00
#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
MIPS: stack protector: Fix per-task canary switch Commit 1400eb6 (MIPS: r4k,octeon,r2300: stack protector: change canary per task) was merged in v3.11 and introduced assembly in the MIPS resume functions to update the value of the current canary in __stack_chk_guard. However it used PTR_L resulting in a load of the canary value, instead of PTR_LA to construct its address. The value is intended to be random but is then treated as an address in the subsequent LONG_S (store). This was observed to cause a fault and panic: CPU 0 Unable to handle kernel paging request at virtual address 139fea20, epc == 8000cc0c, ra == 8034f2a4 Oops[#1]: ... $24 : 139fea20 1e1f7cb6 ... Call Trace: [<8000cc0c>] resume+0xac/0x118 [<8034f2a4>] __schedule+0x5f8/0x78c [<8034f4e0>] schedule_preempt_disabled+0x20/0x2c [<80348eec>] rest_init+0x74/0x84 [<804dc990>] start_kernel+0x43c/0x454 Code: 3c18804b 8f184030 8cb901f8 <af190000> 00c0e021 8cb002f0 8cb102f4 8cb202f8 8cb302fc This can also be forced by modifying arch/mips/include/asm/stackprotector.h so that the default __stack_chk_guard value is more likely to be a bad (or unaligned) pointer. Fix it to use PTR_LA instead, to load the address of the canary value, which the LONG_S can then use to write into it. Reported-by: bobjones (via #mipslinux on IRC) Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gregory Fong <gregory.0xf0@gmail.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/6026/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-10-07 19:14:26 +08:00
PTR_LA t8, __stack_chk_guard
MIPS: r4k,octeon,r2300: stack protector: change canary per task For non-SMP, uses the new random canary value that is stored in the task struct whenever a new task is forked. Based on ARM version in df0698be14c6683606d5df2d83e3ae40f85ed0d9 and subject to the same limitations: the variable GCC expects, __stack_chk_guard, is global, so this will not work on SMP. Quoting Nicolas Pitre <nico@fluxnic.net>: "One way to overcome this GCC limitation would be to locate the __stack_chk_guard variable into a memory page of its own for each CPU, and then use TLB locking to have each CPU see its own page at the same virtual address for each of them." Signed-off-by: Gregory Fong <gregory.0xf0@gmail.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5488/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-06-18 03:36:07 +08:00
LONG_L t9, TASK_STACK_CANARY(a1)
LONG_S t9, 0(t8)
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
/*
* The order of restoring the registers takes care of the race
* updating $28, $29 and kernelsp without disabling ints.
*/
move $28, a2
cpu_restore_nonscratch a1
addiu t1, $28, _THREAD_SIZE - 32
sw t1, kernelsp
mfc0 t1, CP0_STATUS /* Do we really need this? */
li a3, 0xff01
and t1, a3
lw a2, THREAD_STATUS(a1)
nor a3, $0, a3
and a2, a3
or a2, t1
mtc0 a2, CP0_STATUS
move v0, a0
jr ra
END(resume)
/*
* Save a thread's fp context.
*/
LEAF(_save_fp)
fpu_save_single a0, t1 # clobbers t1
jr ra
END(_save_fp)
/*
* Restore a thread's fp context.
*/
LEAF(_restore_fp)
fpu_restore_single a0, t1 # clobbers t1
jr ra
END(_restore_fp)
/*
* Load the FPU with signalling NANS. This bit pattern we're using has
* the property that no matter whether considered as single or as double
* precision represents signaling NANS.
*
MIPS: Respect the ISA level in FCSR handling Define the central place the default FCSR value is set from, initialised in `cpu_probe'. Determine the FCSR mask applied to values written to the register with CTC1 in the full emulation mode and via ptrace(2), according to the ISA level of processor hardware or the writability of bits 31:18 if actual FPU hardware is used. Software may rely on FCSR bits whose functions our emulator does not implement, so it should not allow them to be set or software may get confused. For ptrace(2) it's just sanity. [ralf@linux-mips.org: Fixed double inclusion of <asm/current.h>.] Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9711/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-04 06:27:48 +08:00
* The value to initialize fcr31 to comes in $a0.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
*/
MIPS: Fix build with binutils 2.24.51+ Starting with version 2.24.51.20140728 MIPS binutils complain loudly about mixing soft-float and hard-float object files, leading to this build failure since GCC is invoked with "-msoft-float" on MIPS: {standard input}: Warning: .gnu_attribute 4,3 requires `softfloat' LD arch/mips/alchemy/common/built-in.o mipsel-softfloat-linux-gnu-ld: Warning: arch/mips/alchemy/common/built-in.o uses -msoft-float (set by arch/mips/alchemy/common/prom.o), arch/mips/alchemy/common/sleeper.o uses -mhard-float To fix this, we detect if GAS is new enough to support "-msoft-float" command option, and if it does, we can let GCC pass it to GAS; but then we also need to sprinkle the files which make use of floating point registers with the necessary ".set hardfloat" directives. Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com> Cc: Linux-MIPS <linux-mips@linux-mips.org> Cc: Matthew Fortune <Matthew.Fortune@imgtec.com> Cc: Markos Chandras <Markos.Chandras@imgtec.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Patchwork: https://patchwork.linux-mips.org/patch/8355/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-07 21:13:54 +08:00
.set push
SET_HARDFLOAT
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
LEAF(_init_fpu)
mfc0 t0, CP0_STATUS
li t1, ST0_CU1
or t0, t1
mtc0 t0, CP0_STATUS
MIPS: Respect the ISA level in FCSR handling Define the central place the default FCSR value is set from, initialised in `cpu_probe'. Determine the FCSR mask applied to values written to the register with CTC1 in the full emulation mode and via ptrace(2), according to the ISA level of processor hardware or the writability of bits 31:18 if actual FPU hardware is used. Software may rely on FCSR bits whose functions our emulator does not implement, so it should not allow them to be set or software may get confused. For ptrace(2) it's just sanity. [ralf@linux-mips.org: Fixed double inclusion of <asm/current.h>.] Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9711/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-04 06:27:48 +08:00
ctc1 a0, fcr31
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
li t0, -1
mtc1 t0, $f0
mtc1 t0, $f1
mtc1 t0, $f2
mtc1 t0, $f3
mtc1 t0, $f4
mtc1 t0, $f5
mtc1 t0, $f6
mtc1 t0, $f7
mtc1 t0, $f8
mtc1 t0, $f9
mtc1 t0, $f10
mtc1 t0, $f11
mtc1 t0, $f12
mtc1 t0, $f13
mtc1 t0, $f14
mtc1 t0, $f15
mtc1 t0, $f16
mtc1 t0, $f17
mtc1 t0, $f18
mtc1 t0, $f19
mtc1 t0, $f20
mtc1 t0, $f21
mtc1 t0, $f22
mtc1 t0, $f23
mtc1 t0, $f24
mtc1 t0, $f25
mtc1 t0, $f26
mtc1 t0, $f27
mtc1 t0, $f28
mtc1 t0, $f29
mtc1 t0, $f30
mtc1 t0, $f31
jr ra
END(_init_fpu)
MIPS: Fix build with binutils 2.24.51+ Starting with version 2.24.51.20140728 MIPS binutils complain loudly about mixing soft-float and hard-float object files, leading to this build failure since GCC is invoked with "-msoft-float" on MIPS: {standard input}: Warning: .gnu_attribute 4,3 requires `softfloat' LD arch/mips/alchemy/common/built-in.o mipsel-softfloat-linux-gnu-ld: Warning: arch/mips/alchemy/common/built-in.o uses -msoft-float (set by arch/mips/alchemy/common/prom.o), arch/mips/alchemy/common/sleeper.o uses -mhard-float To fix this, we detect if GAS is new enough to support "-msoft-float" command option, and if it does, we can let GCC pass it to GAS; but then we also need to sprinkle the files which make use of floating point registers with the necessary ".set hardfloat" directives. Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com> Cc: Linux-MIPS <linux-mips@linux-mips.org> Cc: Matthew Fortune <Matthew.Fortune@imgtec.com> Cc: Markos Chandras <Markos.Chandras@imgtec.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Patchwork: https://patchwork.linux-mips.org/patch/8355/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-07 21:13:54 +08:00
.set pop