Commit Graph

170 Commits

Author SHA1 Message Date
Robin Holt 7b6d864b48 reboot: arm: change reboot_mode to use enum reboot_mode
Preparing to move the parsing of reboot= to generic kernel code forces
the change in reboot_mode handling to use the enum.

[akpm@linux-foundation.org: fix arch/arm/mach-socfpga/socfpga.c]
Signed-off-by: Robin Holt <holt@sgi.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Russ Anderson <rja@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:29 -07:00
Robin Holt 16d6d5b00e reboot: arm: prepare reboot_mode for moving to generic kernel code
Prepare for the moving the parsing of reboot= to the generic kernel code
by making reboot_mode into a more generic form.

Signed-off-by: Robin Holt <holt@sgi.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Russ Anderson <rja@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:29 -07:00
Russell King cbd379b100 Merge branches 'fixes', 'mcpm', 'misc' and 'mmci' into for-next 2013-06-29 11:43:28 +01:00
André Hentschel a4780adeef ARM: 7735/2: Preserve the user r/w register TPIDRURW on context switch and fork
Since commit 6a1c53124a the user writeable TLS register was zeroed to
prevent it from being used as a covert channel between two tasks.

There are more and more applications coming to Windows RT,
Wine could support them, but mostly they expect to have
the thread environment block (TEB) in TPIDRURW.

This patch preserves that register per thread instead of clearing it.
Unlike the TPIDRURO, which is already switched, the TPIDRURW
can be updated from userspace so needs careful treatment in the case that we
modify TPIDRURW and call fork(). To avoid this we must always read
TPIDRURW in copy_thread.

Signed-off-by: André Hentschel <nerv@dawncrow.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jonathan Austin <jonathan.austin@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-06-24 15:21:59 +01:00
Stephen Warren 19ab428f4b ARM: 7759/1: decouple CPU offlining from reboot/shutdown
Add comments to machine_shutdown()/halt()/power_off()/restart() that
describe their purpose and/or requirements re: CPUs being active/not.

In machine_shutdown(), replace the call to smp_send_stop() with a call to
disable_nonboot_cpus(). This completely disables all but one CPU, thus
satisfying the requirement that only a single CPU be active for kexec.
Adjust Kconfig dependencies for this change.

In machine_halt()/power_off()/restart(), call smp_send_stop() directly,
rather than via machine_shutdown(); these functions don't need to
completely de-activate all CPUs using hotplug, but rather just quiesce
them.

Remove smp_kill_cpus(), and its call from smp_send_stop().
smp_kill_cpus() was indirectly calling smp_ops.cpu_kill() without calling
smp_ops.cpu_die() on the target CPUs first. At least some implementations
of smp_ops had issues with this; it caused cpu_kill() to hang on Tegra,
for example. Since smp_send_stop() is only used for shutdown, halt, and
power-off, there is no need to attempt any kind of CPU hotplug here.

Adjust Kconfig to reflect that machine_shutdown() (and hence kexec)
relies upon disable_nonboot_cpus(). However, this alone doesn't guarantee
that hotplug will work, or even that hotplug is implemented for a
particular piece of HW that a multi-platform zImage runs on. Hence, add
error-checking to machine_kexec() to determine whether it did work.

Suggested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by:  Zhangfei Gao <zhangfei.gao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-06-17 21:35:25 +01:00
Steven Capper 4ca46c5e1f ARM: 7727/1: remove the .vm_mm value from gate_vma
If one reads /proc/$PID/smaps, the mmap_sem belonging to the
address space of the task being examined is locked for reading.
All the pages of the vmas belonging to the task's address space
are then walked with this lock held.

If a gate_vma is present in the architecture, it too is examined
by the fs/proc/task_mmu.c code. As gate_vma doesn't belong to the
address space of the task though, its pages are not walked.

A recent cleanup (commit f6604efe) of the gate_vma initialisation
code set the vm_mm value to &init_mm. Unfortunately a non-NULL
vm_mm value in the gate_vma will cause the task_mmu code to attempt
to walk the pages of the gate_vma (with no mmap-sem lock held). If
one enables Transparent Huge Page support and vm debugging, this
will then cause OOPses as pmd_trans_huge_lock is called without
mmap_sem being locked.

This patch removes the .vm_mm value from gate_vma, restoring the
original behaviour of the task_mmu code.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-05-22 22:01:36 +01:00
Linus Torvalds 8546dc1d4b Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM updates from Russell King:
 "The major items included in here are:

   - MCPM, multi-cluster power management, part of the infrastructure
     required for ARMs big.LITTLE support.

   - A rework of the ARM KVM code to allow re-use by ARM64.

   - Error handling cleanups of the IS_ERR_OR_NULL() madness and fixes
     of that stuff for arch/arm

   - Preparatory patches for Cortex-M3 support from Uwe Kleine-König.

  There is also a set of three patches in here from Hugh/Catalin to
  address freeing of inappropriate page tables on LPAE.  You already
  have these from akpm, but they were already part of my tree at the
  time he sent them, so unfortunately they'll end up with duplicate
  commits"

* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (77 commits)
  ARM: EXYNOS: remove unnecessary use of IS_ERR_VALUE()
  ARM: IMX: remove unnecessary use of IS_ERR_VALUE()
  ARM: OMAP: use consistent error checking
  ARM: cleanup: OMAP hwmod error checking
  ARM: 7709/1: mcpm: Add explicit AFLAGS to support v6/v7 multiplatform kernels
  ARM: 7700/2: Make cpu_init() notrace
  ARM: 7702/1: Set the page table freeing ceiling to TASK_SIZE
  ARM: 7701/1: mm: Allow arch code to control the user page table ceiling
  ARM: 7703/1: Disable preemption in broadcast_tlb*_a15_erratum()
  ARM: mcpm: provide an interface to set the SMP ops at run time
  ARM: mcpm: generic SMP secondary bringup and hotplug support
  ARM: mcpm_head.S: vlock-based first man election
  ARM: mcpm: Add baremetal voting mutexes
  ARM: mcpm: introduce helpers for platform coherency exit/setup
  ARM: mcpm: introduce the CPU/cluster power API
  ARM: multi-cluster PM: secondary kernel entry code
  ARM: cacheflush: add synchronization helpers for mixed cache state accesses
  ARM: cpu hotplug: remove majority of cache flushing from platforms
  ARM: smp: flush L1 cache in cpu_die()
  ARM: tegra: remove tegra specific cpu_disable()
  ...
2013-05-03 09:13:19 -07:00
Russell King 33b9f582c5 Merge branch 'cleanup' into for-linus
Conflicts:
	arch/arm/plat-omap/dmtimer.c
2013-05-02 21:31:29 +01:00
Tejun Heo a43cb95d54 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>
2013-04-30 17:04:02 -07:00
Thomas Gleixner f7b861b7a6 arm: Use generic idle loop
Use the generic idle loop and replace enable/disable_hlt with the
respective core functions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Tested-by: Kevin Hilman <khilman@linaro.org> # OMAP
Link: http://lkml.kernel.org/r/20130321215233.826238797@linutronix.de
2013-04-08 17:39:24 +02:00
Thomas Gleixner 6546327ad1 arch: Cleanup enable/disable_hlt
enable/disable_hlt() does not need to be exported and can be killed on
architectures which do not use it at all.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Link: http://lkml.kernel.org/r/20130321215233.377959540@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-08 17:39:22 +02:00
Russell King f6604efe0b ARM: cleanup gate_vma initialization
Three's no need to have code initializing this by hand; it's more
efficient to initialize the constant structure members directly.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-02-23 17:55:39 +00:00
Len Brown b0ea11497c ARM idle: delete pm_idle
pm_idle() on ARM was a synonym for default_idle(),
so simply invoke default_idle() directly.

Signed-off-by: Len Brown <len.brown@intel.com>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Kevin Hilman <khilman@linaro.org>
2013-02-17 23:37:04 -05:00
Linus Torvalds 9977d9b379 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull big execve/kernel_thread/fork unification series from Al Viro:
 "All architectures are converted to new model.  Quite a bit of that
  stuff is actually shared with architecture trees; in such cases it's
  literally shared branch pulled by both, not a cherry-pick.

  A lot of ugliness and black magic is gone (-3KLoC total in this one):

   - kernel_thread()/kernel_execve()/sys_execve() redesign.

     We don't do syscalls from kernel anymore for either kernel_thread()
     or kernel_execve():

     kernel_thread() is essentially clone(2) with callback run before we
     return to userland, the callbacks either never return or do
     successful do_execve() before returning.

     kernel_execve() is a wrapper for do_execve() - it doesn't need to
     do transition to user mode anymore.

     As a result kernel_thread() and kernel_execve() are
     arch-independent now - they live in kernel/fork.c and fs/exec.c
     resp.  sys_execve() is also in fs/exec.c and it's completely
     architecture-independent.

   - daemonize() is gone, along with its parts in fs/*.c

   - struct pt_regs * is no longer passed to do_fork/copy_process/
     copy_thread/do_execve/search_binary_handler/->load_binary/do_coredump.

   - sys_fork()/sys_vfork()/sys_clone() unified; some architectures
     still need wrappers (ones with callee-saved registers not saved in
     pt_regs on syscall entry), but the main part of those suckers is in
     kernel/fork.c now."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (113 commits)
  do_coredump(): get rid of pt_regs argument
  print_fatal_signal(): get rid of pt_regs argument
  ptrace_signal(): get rid of unused arguments
  get rid of ptrace_signal_deliver() arguments
  new helper: signal_pt_regs()
  unify default ptrace_signal_deliver
  flagday: kill pt_regs argument of do_fork()
  death to idle_regs()
  don't pass regs to copy_process()
  flagday: don't pass regs to copy_thread()
  bfin: switch to generic vfork, get rid of pointless wrappers
  xtensa: switch to generic clone()
  openrisc: switch to use of generic fork and clone
  unicore32: switch to generic clone(2)
  score: switch to generic fork/vfork/clone
  c6x: sanitize copy_thread(), get rid of clone(2) wrapper, switch to generic clone()
  take sys_fork/sys_vfork/sys_clone prototypes to linux/syscalls.h
  mn10300: switch to generic fork/vfork/clone
  h8300: switch to generic fork/vfork/clone
  tile: switch to generic clone()
  ...

Conflicts:
	arch/microblaze/include/asm/Kbuild
2012-12-12 12:22:13 -08:00
Al Viro afa86fc426 flagday: don't pass regs to copy_thread()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-28 23:43:42 -05:00
Al Viro 38a61b6b4a arm: switch to generic fork/vfork/clone
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-28 22:13:54 -05:00
Nicolas Pitre 9ecb47de34 ARM: 7574/1: kernel/process.c: include idmap.h instead of redeclaring setup_mm_for_reboot()
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-11-13 11:47:41 +00:00
fwu 871df85a59 ARM: 7544/1: Add BUG_ON when hlt counter is wrongly used
1. On ARM platform, "nohlt" can be used to prevent core from idle
   process, returning immediately.
2. There are two interfaces, exported for other modules, named
   "disable_hlt" and "enable_hlt" are used to enable/disable the
   cpuidle mechanism by increasing/decreasing "hlt_counter".
   Disable_hlt and enable_hlt are paired operation,
   when you first call disable_hlt and then enable_hlt, the
   semantics are right.
3. There is no obvious constraint to prevent user(driver/module)
   code to prevent the case that enable_hlt is ahead of disable_hlt,
   which is a fatal operation on kernel state change from user,
   and there is no any WARNING or notification if the case happens
   in current kernel code.
   This patch aims to report BUG when the case happens, just like
   what the kernel do when enable_irq is ahead of disable_irq.

Link: https://patchwork.kernel.org/patch/1527881/

Signed-off-by: fwu <fwu@marvell.com>
Signed-off-by: YiLu Mao <ylmao@marvell.com>
Signed-off-by: Ning Jiang <ning.jiang@marvell.com>
Acked-by: Nicolas Pitre
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-10-18 11:06:43 +01:00
Linus Torvalds 4e21fc138b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull third pile of kernel_execve() patches from Al Viro:
 "The last bits of infrastructure for kernel_thread() et.al., with
  alpha/arm/x86 use of those.  Plus sanitizing the asm glue and
  do_notify_resume() on alpha, fixing the "disabled irq while running
  task_work stuff" breakage there.

  At that point the rest of kernel_thread/kernel_execve/sys_execve work
  can be done independently for different architectures.  The only
  pending bits that do depend on having all architectures converted are
  restrictred to fs/* and kernel/* - that'll obviously have to wait for
  the next cycle.

  I thought we'd have to wait for all of them done before we start
  eliminating the longjump-style insanity in kernel_execve(), but it
  turned out there's a very simple way to do that without flagday-style
  changes."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
  alpha: switch to saner kernel_execve() semantics
  arm: switch to saner kernel_execve() semantics
  x86, um: convert to saner kernel_execve() semantics
  infrastructure for saner ret_from_kernel_thread semantics
  make sure that kernel_thread() callbacks call do_exit() themselves
  make sure that we always have a return path from kernel_execve()
  ppc: eeh_event should just use kthread_run()
  don't bother with kernel_thread/kernel_execve for launching linuxrc
  alpha: get rid of switch_stack argument of do_work_pending()
  alpha: don't bother passing switch_stack separately from regs
  alpha: take SIGPENDING/NOTIFY_RESUME loop into signal.c
  alpha: simplify TIF_NEED_RESCHED handling
2012-10-13 10:05:52 +09:00
Al Viro 9fff2fa0db arm: switch to saner kernel_execve() semantics
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-12 13:35:23 -04:00
Linus Torvalds 42859eea96 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull generic execve() changes from Al Viro:
 "This introduces the generic kernel_thread() and kernel_execve()
  functions, and switches x86, arm, alpha, um and s390 over to them."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits)
  s390: convert to generic kernel_execve()
  s390: switch to generic kernel_thread()
  s390: fold kernel_thread_helper() into ret_from_fork()
  s390: fold execve_tail() into start_thread(), convert to generic sys_execve()
  um: switch to generic kernel_thread()
  x86, um/x86: switch to generic sys_execve and kernel_execve
  x86: split ret_from_fork
  alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
  alpha: switch to generic kernel_thread()
  alpha: switch to generic sys_execve()
  arm: get rid of execve wrapper, switch to generic execve() implementation
  arm: optimized current_pt_regs()
  arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
  arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk]
  generic sys_execve()
  generic kernel_execve()
  new helper: current_pt_regs()
  preparation for generic kernel_thread()
  um: kill thread->forking
  um: let signal_delivered() do SIGTRAP on singlestepping into handler
  ...
2012-10-10 12:02:25 +09:00
Al Viro 9e14f828ee arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-30 22:21:36 -04:00
Arnd Bergmann 19e4ab54e7 Merge branch 'for-arm-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds into next/drivers
From Bryan Wu <bryan.wu@canonical.com>:

Based on Linus Walleij's ARM LED consolidation work, this patchset introduce a
new generic led trigger for CPU not only for ARM but also for others.

For enabling CPU idle event, CPU arch code should call ledtrig_cpu() stub to
trigger idle start or idle end event.

These patches convert old style LED driver in arch/arm to gpio_led or new led
driver interface. Against 3.5 release and build successfully for all the machines.

Test ledtrig-cpu driver on OMAP4 Panda board.

v9 --> v10
 * fix compiling issue on versatile_defconfig reported by Russell King
 * rebase to 3.5 kernel and move patches to new git tree

v8 --> v9:
 * use mutex to replace rw_sema pointed out by Tim Gardner
 * add a new struct led_trigger_cpu
 * add lock_is_inited to record mutex lock initialization

v6 --> v7:
 * add a patch to unify the led-trigger name
 * fix some typo pointed
 * use BUG_ON to detect CPU numbers during building stage

v5 --> v6:
 * replace  __get_cpu_var() to per_cpu()
 * remove smp_processor_id() which is wrong with for_each_possible_cpu()
 * test on real OMAP4 Panda board
 * add comments about CPU hotplug in the CPU LED trigger driver

v4 --> v5:
 * rebase all the patches on top of latest linux-next
 * replace on_each_cpu() with for_each_possible_cpu()
 * add some description of ledtrig_cpu() API
 * remove old leds code from driver nwflash.c, which should use a new led trigger then
 * this trigger driver can be built as module now

v3 --> v4:
 * fix a typo pointed by Jochen Friedrich
 * fix some building errors
 * add Reviewed-by and Tested-by into patch log

v2 --> v3:
 * almost rewrote the whole ledtrig-cpu driver, which is more simple
 * every CPU will have a per-CPU trigger
 * cpu trigger can be assigned to any leds
 * fix a lockdep issue in led-trigger common code
 * other fix according to review

v1 --> v2:
 * remove select operations in Kconfig of every machines
 * add back supporting of led in core module of mach-integrator
 * solidate name scheme in ledtrig-cpu.c
 * add comments of CPU_LED_* cpu led events
 * fold patches of RealView and Versatile together
 * add machine_is_ check during assabet led driver init
 * add some Acked-by in patch logs
 * remove code for simpad machine in machine-sa11000, since Jochen Friedrich
   introduced gpiolib and gpio-led driver for simpad
 * on Assabet and Netwinder machine, LED operations is reversed like:
   setting bit means turn off leds
   clearing bit means turn on leds
 * add a new function to read CM_CTRL register for led driver

* 'for-arm-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds:
  ARM: use new LEDS CPU trigger stub to replace old one
  ARM: mach-sa1100: retire custom LED code
  ARM: mach-omap1: retire custom LED code
  ARM: mach-pnx4008: remove including old leds event API header file
  ARM: plat-samsung: remove including old leds event API header file
  ARM: mach-pxa: retire custom LED code
  char: nwflash: remove old led event code
  ARM: mach-footbridge: retire custom LED code
  ARM: mach-ebsa110: retire custom LED code
  ARM: mach-clps711x: retire custom LED code of P720T machine
  ARM: mach-integrator: retire custom LED code
  ARM: mach-integrator: move CM_CTRL to header file for accessing by other functions
  ARM: mach-orion5x: convert custom LED code to gpio_led and LED CPU trigger
  ARM: mach-shark: retire custom LED code
  ARM: mach-ks8695: remove leds driver, since nobody use it
  ARM: mach-realview and mach-versatile: retire custom LED code
  ARM: at91: convert old leds drivers to gpio_led and led_trigger drivers
  led-triggers: create a trigger for CPU activity

Conflicts:
	arch/arm/mach-clps711x/p720t.c
	arch/arm/mach-sa1100/leds-cerf.c
	arch/arm/mach-sa1100/leds-lart.c

Let's hope this is the last time we pull this and it doesn't cause
more trouble. I have verified that version 10 causes no build
warnings or errors any more, and the patches still look good.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2012-08-13 16:45:48 +02:00
Bryan Wu fa8bbb13ab ARM: use new LEDS CPU trigger stub to replace old one
Cc:  Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
2012-08-01 11:22:14 +08:00
Shawn Guo 98bd8b96b2 ARM: 7466/1: disable interrupt before spinning endlessly
The CPU will endlessly spin at the end of machine_halt and
machine_restart calls.  However, this will lead to a soft lockup
warning after about 20 seconds, if CONFIG_LOCKUP_DETECTOR is enabled,
as system timer is still alive.

Disable interrupt before going to spin endlessly, so that the lockup
warning will never be seen.

Cc: <stable@vger.kernel.org>
Reported-by: Marek Vasut <marex@denx.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-31 10:30:31 +01:00
Thomas Gleixner 448eca9093 arm: Remove unused cpu_idle_wait()
cpuidle uses a generic function now. Remove the unused code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Link: http://lkml.kernel.org/r/20120507175652.260797846@linutronix.de
2012-05-08 12:35:06 +02:00
Linus Torvalds 12679a2d7e Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm
Pull more ARM updates from Russell King.

This got a fair number of conflicts with the <asm/system.h> split, but
also with some other sparse-irq and header file include cleanups.  They
all looked pretty trivial, though.

* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (59 commits)
  ARM: fix Kconfig warning for HAVE_BPF_JIT
  ARM: 7361/1: provide XIP_VIRT_ADDR for no-MMU builds
  ARM: 7349/1: integrator: convert to sparse irqs
  ARM: 7259/3: net: JIT compiler for packet filters
  ARM: 7334/1: add jump label support
  ARM: 7333/2: jump label: detect %c support for ARM
  ARM: 7338/1: add support for early console output via semihosting
  ARM: use set_current_blocked() and block_sigmask()
  ARM: exec: remove redundant set_fs(USER_DS)
  ARM: 7332/1: extract out code patch function from kprobes
  ARM: 7331/1: extract out insn generation code from ftrace
  ARM: 7330/1: ftrace: use canonical Thumb-2 wide instruction format
  ARM: 7351/1: ftrace: remove useless memory checks
  ARM: 7316/1: kexec: EOI active and mask all interrupts in kexec crash path
  ARM: Versatile Express: add NO_IOPORT
  ARM: get rid of asm/irq.h in asm/prom.h
  ARM: 7319/1: Print debug info for SIGBUS in user faults
  ARM: 7318/1: gic: refactor irq_start assignment
  ARM: 7317/1: irq: avoid NULL check in for_each_irq_desc loop
  ARM: 7315/1: perf: add support for the Cortex-A7 PMU
  ...
2012-03-29 16:53:48 -07:00
Linus Torvalds 0195c00244 Disintegrate and delete asm/system.h
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Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system

Pull "Disintegrate and delete asm/system.h" from David Howells:
 "Here are a bunch of patches to disintegrate asm/system.h into a set of
  separate bits to relieve the problem of circular inclusion
  dependencies.

  I've built all the working defconfigs from all the arches that I can
  and made sure that they don't break.

  The reason for these patches is that I recently encountered a circular
  dependency problem that came about when I produced some patches to
  optimise get_order() by rewriting it to use ilog2().

  This uses bitops - and on the SH arch asm/bitops.h drags in
  asm-generic/get_order.h by a circuituous route involving asm/system.h.

  The main difficulty seems to be asm/system.h.  It holds a number of
  low level bits with no/few dependencies that are commonly used (eg.
  memory barriers) and a number of bits with more dependencies that
  aren't used in many places (eg.  switch_to()).

  These patches break asm/system.h up into the following core pieces:

    (1) asm/barrier.h

        Move memory barriers here.  This already done for MIPS and Alpha.

    (2) asm/switch_to.h

        Move switch_to() and related stuff here.

    (3) asm/exec.h

        Move arch_align_stack() here.  Other process execution related bits
        could perhaps go here from asm/processor.h.

    (4) asm/cmpxchg.h

        Move xchg() and cmpxchg() here as they're full word atomic ops and
        frequently used by atomic_xchg() and atomic_cmpxchg().

    (5) asm/bug.h

        Move die() and related bits.

    (6) asm/auxvec.h

        Move AT_VECTOR_SIZE_ARCH here.

  Other arch headers are created as needed on a per-arch basis."

Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that.  We'll find out anything that got broken and fix it..

* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
  Delete all instances of asm/system.h
  Remove all #inclusions of asm/system.h
  Add #includes needed to permit the removal of asm/system.h
  Move all declarations of free_initmem() to linux/mm.h
  Disintegrate asm/system.h for OpenRISC
  Split arch_align_stack() out from asm-generic/system.h
  Split the switch_to() wrapper out of asm-generic/system.h
  Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
  Create asm-generic/barrier.h
  Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
  Disintegrate asm/system.h for Xtensa
  Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
  Disintegrate asm/system.h for Tile
  Disintegrate asm/system.h for Sparc
  Disintegrate asm/system.h for SH
  Disintegrate asm/system.h for Score
  Disintegrate asm/system.h for S390
  Disintegrate asm/system.h for PowerPC
  Disintegrate asm/system.h for PA-RISC
  Disintegrate asm/system.h for MN10300
  ...
2012-03-28 15:58:21 -07:00
David Howells 9f97da78bf Disintegrate asm/system.h for ARM
Disintegrate asm/system.h for ARM.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Russell King <linux@arm.linux.org.uk>
cc: linux-arm-kernel@lists.infradead.org
2012-03-28 18:30:01 +01:00
Russell King b0df898680 Merge branch 'devel-stable' into for-linus
Conflicts:
	arch/arm/Kconfig.debug
	arch/arm/plat-versatile/Kconfig
Merge fixes:
	arch/arm/mach-integrator/Kconfig
	drivers/clocksource/Kconfig
2012-03-27 11:30:31 +01:00
Will Deacon f9d4861fc3 ARM: 7294/1: vectors: use gate_vma for vectors user mapping
The current user mapping for the vectors page is inserted as a `horrible
hack vma' into each task via arch_setup_additional_pages. This causes
problems with the MM subsystem and vm_normal_page, as described here:

https://lkml.org/lkml/2012/1/14/55

Following the suggestion from Hugh in the above thread, this patch uses
the gate_vma for the vectors user mapping, therefore consolidating
the horrible hack VMAs into one.

Acked-and-Tested-by: Nicolas Pitre <nico@linaro.org>

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-03-24 09:38:51 +00:00
Linus Torvalds 56c10bf82c Merge branch 'for-armsoc' of git://git.linaro.org/people/rmk/linux-arm
Pull #1 ARM updates from Russell King:
 "This one covers stuff which Arnd is waiting for me to push, as this is
  shared between both our trees and probably other trees elsewhere.

  Essentially, this contains:
   - AMBA primecell device initializer updates - mostly shrinking the
     size of the device declarations in platform code to something more
     reasonable.
   - Getting rid of the NO_IRQ crap from AMBA primecell stuff.
   - Nicolas' idle cleanups.  This in combination with the restart
     cleanups from the last merge window results in a great many
     mach/system.h files being deleted."

Yay: ~80 files, ~2000 lines deleted.

* 'for-armsoc' of git://git.linaro.org/people/rmk/linux-arm: (60 commits)
  ARM: remove disable_fiq and arch_ret_to_user macros
  ARM: make entry-macro.S depend on !MULTI_IRQ_HANDLER
  ARM: rpc: make default fiq handler run-time installed
  ARM: make arch_ret_to_user macro optional
  ARM: amba: samsung: use common amba device initializers
  ARM: amba: spear: use common amba device initializers
  ARM: amba: nomadik: use common amba device initializers
  ARM: amba: u300: use common amba device initializers
  ARM: amba: lpc32xx: use common amba device initializers
  ARM: amba: netx: use common amba device initializers
  ARM: amba: bcmring: use common amba device initializers
  ARM: amba: ep93xx: use common amba device initializers
  ARM: amba: omap2: use common amba device initializers
  ARM: amba: integrator: use common amba device initializers
  ARM: amba: realview: get rid of private platform amba_device initializer
  ARM: amba: versatile: get rid of private platform amba_device initializer
  ARM: amba: vexpress: get rid of private platform amba_device initializer
  ARM: amba: provide common initializers for static amba devices
  ARM: amba: make use of -1 IRQs warn
  ARM: amba: u300: get rid of NO_IRQ initializers
  ...
2012-03-23 17:30:49 -07:00
Jason Baron 909af768e8 coredump: remove VM_ALWAYSDUMP flag
The motivation for this patchset was that I was looking at a way for a
qemu-kvm process, to exclude the guest memory from its core dump, which
can be quite large.  There are already a number of filter flags in
/proc/<pid>/coredump_filter, however, these allow one to specify 'types'
of kernel memory, not specific address ranges (which is needed in this
case).

Since there are no more vma flags available, the first patch eliminates
the need for the 'VM_ALWAYSDUMP' flag.  The flag is used internally by
the kernel to mark vdso and vsyscall pages.  However, it is simple
enough to check if a vma covers a vdso or vsyscall page without the need
for this flag.

The second patch then replaces the 'VM_ALWAYSDUMP' flag with a new
'VM_NODUMP' flag, which can be set by userspace using new madvise flags:
'MADV_DONTDUMP', and unset via 'MADV_DODUMP'.  The core dump filters
continue to work the same as before unless 'MADV_DONTDUMP' is set on the
region.

The qemu code which implements this features is at:

  http://people.redhat.com/~jbaron/qemu-dump/qemu-dump.patch

In my testing the qemu core dump shrunk from 383MB -> 13MB with this
patch.

I also believe that the 'MADV_DONTDUMP' flag might be useful for
security sensitive apps, which might want to select which areas are
dumped.

This patch:

The VM_ALWAYSDUMP flag is currently used by the coredump code to
indicate that a vma is part of a vsyscall or vdso section.  However, we
can determine if a vma is in one these sections by checking it against
the gate_vma and checking for a non-NULL return value from
arch_vma_name().  Thus, freeing a valuable vma bit.

Signed-off-by: Jason Baron <jbaron@redhat.com>
Acked-by: Roland McGrath <roland@hack.frob.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23 16:58:42 -07:00
Thomas Gleixner bd2f55361f sched/rt: Use schedule_preempt_disabled()
Coccinelle based conversion.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-24swm5zut3h9c4a6s46x8rws@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-01 10:28:03 +01:00
Nicolas Pitre ae94091303 ARM: substitute arch_idle()
Now that all implementations of arch_idle() are equivalent to cpu_do_idle()
we can just use the later directly and stop including mach/system.h.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-and-tested-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
2012-01-20 18:55:19 -05:00
Nicolas Pitre 4fa20439a8 ARM: clean up idle handlers
Let's factor out the need_resched() check instead of having it duplicated
in every pm_idle implementations to avoid inconsistencies (omap2_pm_idle
is missing it already).

The forceful re-enablement of IRQs after pm_idle has returned can go.
The warning certainly doesn't trigger for existing users.

To get rid of the pm_idle calling convention oddity, let's introduce
arm_pm_idle() allowing for the local_irq_enable() to be factored out
from SOC specific implementations. The default pm_idle function becomes
a wrapper for arm_pm_idle and it takes care of enabling IRQs closer to
where they are initially disabled.

And finally move the comment explaining the reason for that turning off
of IRQs to a more proper location.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-and-tested-by: Jamie Iles <jamie@jamieiles.com>
2012-01-20 18:55:05 -05:00
Linus Torvalds 770e1b035d Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm
* 'for-linus' of git://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm: (207 commits)
  ARM: 7267/1: Remove BUILD_BUG_ON from asm/bug.h
  ARM: 7269/1: mach-sa1100: fix sched_clock breakage
  ARM: 7198/1: arm/imx6: add restart support for imx6q
  ARM: restart: remove the now empty arch_reset()
  ARM: restart: remove comments about adding code to arch_reset()
  ARM: restart: lpc32xx & u300: remove unnecessary printk
  ARM: restart: plat-samsung: remove plat/reset.h and s5p_reset_hook
  ARM: restart: w90x900: use new restart hook
  ARM: restart: Versatile Express: use new restart hook
  ARM: restart: versatile: use new restart hook
  ARM: restart: u300: use new restart hook
  ARM: restart: tegra: use new restart hook
  ARM: restart: spear: use new restart hook
  ARM: restart: shark: use new restart hook
  ARM: restart: sa1100: use new restart hook
  ARM: 7252/1: restart: S5PV210: use new restart hook
  ARM: 7251/1: restart: S5PC100: use new restart hook
  ARM: 7250/1: restart: S5P64X0: use new restart hook
  ARM: 7266/1: restart: S3C64XX: use new restart hook
  ARM: 7265/1: restart: S3C24XX: use new restart hook
  ...

Fix up trivial conflict in arch/arm/mm/init.c due to removal of
memblock_init() clashing with the movement of the sorting of the meminfo
array.
2012-01-06 18:15:25 -08:00
Russell King 7b9dd47136 Merge branch 'restart' into for-linus
Conflicts:
	arch/arm/mach-exynos/cpu.c

The changes to arch/arm/mach-exynos/cpu.c were moved to
mach-exynos/common.c.
2012-01-05 13:25:27 +00:00
Russell King f88b8979d2 ARM: restart: remove the now empty arch_reset()
Remove the now empty arch_reset() from all the mach/system.h includes,
and remove its callsite.  Remove arm_machine_restart() as this function
no longer does anything useful.

For samsung platforms, remove the include of mach/system-reset.h and
plat/system-reset.h from their respective mach/system.h headers as these
just define their arch_reset functions.  As a result, the s3c2410 and
plat-samsung system-reset.h files are no longer referenced, so remove
these files entirely.

Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-01-05 12:57:22 +00:00
Russell King 4045407fd7 Merge branch 'restart-cleanup' into restart
Conflicts:
	arch/arm/kernel/setup.c
2012-01-05 12:56:44 +00:00
Will Deacon 290130a177 ARM: reset: implement soft_restart for jumping to a physical address
Tools such as kexec and CPU hotplug require a way to reset the processor
and branch to some code in physical space. This requires various bits of
jiggery pokery with the caches and MMU which, when it goes wrong, tends
to lock up the system.

This patch fleshes out the soft_restart implementation so that it
branches to the reset code using the identity mapping. This requires us
to change to a temporary stack, held within the kernel image as a static
array, to avoid conflicting with the new view of memory.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-12-12 16:07:35 +00:00
Frederic Weisbecker 1268fbc746 nohz: Remove tick_nohz_idle_enter_norcu() / tick_nohz_idle_exit_norcu()
Those two APIs were provided to optimize the calls of
tick_nohz_idle_enter() and rcu_idle_enter() into a single
irq disabled section. This way no interrupt happening in-between would
needlessly process any RCU job.

Now we are talking about an optimization for which benefits
have yet to be measured. Let's start simple and completely decouple
idle rcu and dyntick idle logics to simplify.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-12-11 10:31:57 -08:00
Frederic Weisbecker 2bbb6817c0 nohz: Allow rcu extended quiescent state handling seperately from tick stop
It is assumed that rcu won't be used once we switch to tickless
mode and until we restart the tick. However this is not always
true, as in x86-64 where we dereference the idle notifiers after
the tick is stopped.

To prepare for fixing this, add two new APIs:
tick_nohz_idle_enter_norcu() and tick_nohz_idle_exit_norcu().

If no use of RCU is made in the idle loop between
tick_nohz_enter_idle() and tick_nohz_exit_idle() calls, the arch
must instead call the new *_norcu() version such that the arch doesn't
need to call rcu_idle_enter() and rcu_idle_exit().

Otherwise the arch must call tick_nohz_enter_idle() and
tick_nohz_exit_idle() and also call explicitly:

- rcu_idle_enter() after its last use of RCU before the CPU is put
to sleep.
- rcu_idle_exit() before the first use of RCU after the CPU is woken
up.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: David Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-12-11 10:31:36 -08:00
Frederic Weisbecker 280f06774a nohz: Separate out irq exit and idle loop dyntick logic
The tick_nohz_stop_sched_tick() function, which tries to delay
the next timer tick as long as possible, can be called from two
places:

- From the idle loop to start the dytick idle mode
- From interrupt exit if we have interrupted the dyntick
idle mode, so that we reprogram the next tick event in
case the irq changed some internal state that requires this
action.

There are only few minor differences between both that
are handled by that function, driven by the ts->inidle
cpu variable and the inidle parameter. The whole guarantees
that we only update the dyntick mode on irq exit if we actually
interrupted the dyntick idle mode, and that we enter in RCU extended
quiescent state from idle loop entry only.

Split this function into:

- tick_nohz_idle_enter(), which sets ts->inidle to 1, enters
dynticks idle mode unconditionally if it can, and enters into RCU
extended quiescent state.

- tick_nohz_irq_exit() which only updates the dynticks idle mode
when ts->inidle is set (ie: if tick_nohz_idle_enter() has been called).

To maintain symmetry, tick_nohz_restart_sched_tick() has been renamed
into tick_nohz_idle_exit().

This simplifies the code and micro-optimize the irq exit path (no need
for local_irq_save there). This also prepares for the split between
dynticks and rcu extended quiescent state logics. We'll need this split to
further fix illegal uses of RCU in extended quiescent states in the idle
loop.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: David Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-12-11 10:31:35 -08:00
Russell King 742eaa6a6e Merge branch 'for-rmk' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into devel-stable
Conflicts:
	arch/arm/common/gic.c
	arch/arm/plat-omap/include/plat/common.h
2011-12-05 23:20:17 +00:00
Will Deacon 11ed0ba175 ARM: 7161/1: errata: no automatic store buffer drain
This patch implements a workaround for PL310 erratum 769419. On
revisions of the PL310 prior to r3p2, the Store Buffer does not
automatically drain. This can cause normal, non-cacheable writes to be
retained when the memory system is idle, leading to suboptimal I/O
performance for drivers using coherent DMA.

This patch adds an optional wmb() call to the cpu_idle loop. On systems
with an outer cache, this causes an explicit flush of the store buffer.

Cc: stable@vger.kernel.org
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-11-21 13:12:18 +00:00
Russell King e879c862fb ARM: restart: only perform setup for restart when soft-restarting
We only need to set the system up for a soft-restart if we're going to
be doing a soft-restart.  Provide a new function (soft_restart()) which
does the setup and final call for this, and make platforms use it.
Eliminate the call to setup_restart() from the default handler.

This means that platforms arch_reset() function is no longer called with
the page tables prepared for a soft-restart, and caches will still be
enabled.

Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: Krzysztof Ha■asa <khc@pm.waw.pl>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Acked-by: Wan ZongShun <mcuos.com@gmail.com>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-11-21 09:47:48 +00:00
Russell King 5aafec15bd ARM: restart: remove argument to setup_mm_for_reboot()
setup_mm_for_reboot() doesn't make use of its argument, so remove it.

Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-11-10 22:30:28 +00:00
Russell King ac15e00b1e ARM: restart: move reboot failure handing into machine_restart()
Move the failure to reboot into machine_restart() to always catch
this condition, even if a platform decides to hook the restarting
via arm_pm_restart().

Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-11-10 22:30:20 +00:00
Paul Gortmaker ecea4ab6d3 arm: convert core files from module.h to export.h
Many of the core ARM kernel files are not modules, but just
including module.h for exporting symbols.  Now these files can
use the lighter footprint export.h for this role.

There are probably lots more, but ARM files of mach-* and plat-*
don't get coverage via a simple yesconfig build.  They will have
to be cleaned up and tested via using their respective configs.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:30:49 -04:00
Laura Abbott b380ab4f85 ARM: 7068/1: process: change from __backtrace to dump_stack in show_regs
Currently, show_regs calls __backtrace which does
nothing if CONFIG_FRAME_POINTER is not set. Switch to
dump_stack which handles both CONFIG_FRAME_POINTER and
CONFIG_ARM_UNWIND correctly.

__backtrace is now superseded by dump_stack in general
and show_regs was the last caller so remove __backtrace
as well.

Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-10-17 09:12:41 +01:00
David Brown cbc158d6bf cpuidle: Consistent spelling of cpuidle_idle_call()
Commit a0bfa13738 mispells
cpuidle_idle_call() on ARM and SH code.  Fix this to be consistent.

Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: x86@kernel.org
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: David Brown <davidb@codeaurora.org>
[ Also done by Mark Brown - th ebug has been around forever, and was
  noticed in -next, but the idle tree never picked it up. Bad bad bad ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-08-04 16:35:34 -10:00
Len Brown a0bfa13738 cpuidle: stop depending on pm_idle
cpuidle users should call cpuidle_call_idle() directly
rather than via (pm_idle)() function pointer.

Architecture may choose to continue using (pm_idle)(),
but cpuidle need not depend on it:

  my_arch_cpu_idle()
	...
	if(cpuidle_call_idle())
		pm_idle();

cc: Kevin Hilman <khilman@deeprootsystems.com>
cc: Paul Mundt <lethal@linux-sh.org>
cc: x86@kernel.org
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2011-08-03 19:06:37 -04:00
Catalin Marinas 2e82669acf ARM: 6867/1: Introduce THREAD_NOTIFY_COPY for copy_thread() hooks
This patch adds THREAD_NOTIFY_COPY for calling registered handlers
during the copy_thread() function call. It also changes the VFP handler
to use a switch statement rather than if..else and ignore this event.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-04-10 21:13:36 +01:00
Will Deacon 6cde6d4217 ARM: 6619/1: nommu: avoid mapping vectors page when !CONFIG_MMU
When running without an MMU, we do not need to install a mapping for the
vectors page. Attempting to do so causes a compile-time error because
install_special_mapping is not defined.

This patch adds compile-time guards to the vector mapping functions
so that we can build nommu configurations once more.

Acked-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-01-11 17:32:24 +00:00
Russell King 809b4e00ba Merge branch 'devel-stable' into devel 2010-10-19 22:06:36 +01:00
Russell King 23beab76b4 Merge branches 'at91', 'dcache', 'ftrace', 'hwbpt', 'misc', 'mmci', 's3c', 'st-ux' and 'unwind' into devel 2010-10-18 22:34:25 +01:00
Kevin Hilman c7b0aff44a ARM: 6428/1: add cpu_idle_wait() to support CPUidle on SMP systems.
In order for CPUidle to work on SMP systems, an implementation of
cpu_idle_wait() is needed.

This patch duplicates the x86 implementation of cpu_idle_wait() for
ARM.

Tested-by: Colin Cross <ccross@android.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-10-08 10:02:24 +01:00
Nicolas Pitre ec706dab29 ARM: add a vma entry for the user accessible vector page
The kernel makes the high vector page visible to user space. This page
contains (amongst others) small code segments that can be executed in
user space.  Make this page visible through ptrace and /proc/<pid>/mem
in order to let gdb perform code parsing needed for proper unwinding.

For example, the ERESTART_RESTARTBLOCK handler actually has a stack
frame -- it returns to a PC value stored on the user's stack.   To
unwind after a "sleep" system call was interrupted twice, GDB would
have to recognize this situation and understand that stack frame
layout -- which it currently cannot do.

We could fix this by hard-coding addresses in the vector page range into
GDB, but that isn't really portable as not all of those addresses are
guaranteed to remain stable across kernel releases.  And having the gdb
process make an exception for this page and get  content from its own
address space for it looks strange, and it is not future proof either.

Being located above PAGE_OFFSET, this vma cannot be deleted by
user space code.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2010-10-01 22:35:19 -04:00
Will Deacon 864232fa1a ARM: 6357/1: hw-breakpoint: add new ptrace requests for hw-breakpoint interaction
For debuggers to take advantage of the hw-breakpoint framework in the kernel,
it is necessary to expose the API calls via a ptrace interface.

This patch exposes the hardware breakpoints framework as a collection of
virtual registers, accesible using PTRACE_SETHBPREGS and PTRACE_GETHBPREGS
requests. The breakpoints are stored in the debug_info struct of the running
thread.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: S. Karthikeyan <informkarthik@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-09-08 10:05:00 +01:00
Russell King 7b70c4275f Merge branch 'devel-stable' into devel
Conflicts:
	arch/arm/kernel/entry-armv.S
	arch/arm/kernel/setup.c
	arch/arm/mm/init.c
2010-07-31 14:20:16 +01:00
Russell King 3d3f78d752 ARM: call machine_shutdown() from machine_halt(), etc
x86 calls machine_shutdown() from the various machine_*() calls which
take the machine down ready for halting, restarting, etc, and uses
this to bring the system safely to a point where those actions can be
performed.  Such actions are stopping the secondary CPUs.

So, change the ARM implementation of these to reflect what x86 does.

This solves kexec problems on ARM SMP platforms, where the secondary
CPUs were left running across the kexec call.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-27 10:48:43 +01:00
Russell King 9ca03a21e3 ARM: Factor out common code from cpu_proc_fin()
All implementations of cpu_proc_fin() start by disabling interrupts
and then flush caches.  Rather than have every processors proc_fin()
implementation do this, move it out into generic code - and move the
cache flush past setup_mm_for_reboot() (so it can benefit from having
caches still enabled.)

This allows cpu_proc_fin() to become independent of the L1/L2 cache
types, and eventually move the L2 cache flushing into the L2 support
code.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-27 10:48:42 +01:00
Russell King 14764b01a5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/nico/orion into devel-stable 2010-07-21 09:22:45 +01:00
Russell King ac78884e6d ARM: lockdep: fix unannotated irqs-on
CPU: Testing write buffer coherency: ok
------------[ cut here ]------------
WARNING: at kernel/lockdep.c:3145 check_flags+0xcc/0x1dc()
Modules linked in:
[<c0035120>] (unwind_backtrace+0x0/0xf8) from [<c0355374>] (dump_stack+0x20/0x24)
[<c0355374>] (dump_stack+0x20/0x24) from [<c0060c04>] (warn_slowpath_common+0x58/0x70)
[<c0060c04>] (warn_slowpath_common+0x58/0x70) from [<c0060c3c>] (warn_slowpath_null+0x20/0x24)
[<c0060c3c>] (warn_slowpath_null+0x20/0x24) from [<c008f224>] (check_flags+0xcc/0x1dc)
[<c008f224>] (check_flags+0xcc/0x1dc) from [<c00945dc>] (lock_acquire+0x50/0x140)
[<c00945dc>] (lock_acquire+0x50/0x140) from [<c0358434>] (_raw_spin_lock+0x50/0x88)
[<c0358434>] (_raw_spin_lock+0x50/0x88) from [<c00fd114>] (set_task_comm+0x2c/0x60)
[<c00fd114>] (set_task_comm+0x2c/0x60) from [<c007e184>] (kthreadd+0x30/0x108)
[<c007e184>] (kthreadd+0x30/0x108) from [<c0030104>] (kernel_thread_exit+0x0/0x8)
---[ end trace 1b75b31a2719ed1c ]---
possible reason: unannotated irqs-on.
irq event stamp: 3
hardirqs last  enabled at (2): [<c0059bb0>] finish_task_switch+0x48/0xb0
hardirqs last disabled at (3): [<c002f0b0>] ret_slow_syscall+0xc/0x1c
softirqs last  enabled at (0): [<c005f3e0>] copy_process+0x394/0xe5c
softirqs last disabled at (0): [<(null)>] (null)

Fix this by ensuring that the lockdep interrupt state is manipulated in
the appropriate places.  We essentially treat userspace as an entirely
separate environment which isn't relevant to lockdep (lockdep doesn't
monitor userspace.)  We don't tell lockdep that IRQs will be enabled
in that environment.

Instead, when creating kernel threads (which is a rare event compared
to entering/leaving userspace) we have to update the lockdep state.  Do
this by starting threads with IRQs disabled, and in the kthread helper,
tell lockdep that IRQs are enabled, and enable them.

This provides lockdep with a consistent view of the current IRQ state
in kernel space.

This also revert portions of 0d928b0b61
which didn't fix the problem.

Tested-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-10 10:53:13 +01:00
Nicolas Pitre c743f38013 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: Nicolas Pitre <nicolas.pitre@linaro.org>
2010-06-14 21:31:00 -04:00
Nicolas Pitre 990cb8acf2 [ARM] implement arch_randomize_brk()
For this feature to take effect, CONFIG_COMPAT_BRK must be turned
off.  This can safely be turned off for any EABI user space versions.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2010-06-14 21:22:11 -04:00
Russell King 4260415f6a ARM: fix build error in arch/arm/kernel/process.c
/tmp/ccJ3ssZW.s: Assembler messages:
/tmp/ccJ3ssZW.s:1952: Error: can't resolve `.text' {.text section} - `.LFB1077'

This is caused because:

	.section .data
	.section .text
	.section .text
	.previous

does not return us to the .text section, but the .data section; this
makes use of .previous dangerous if the ordering of previous sections
is not known.

Fix up the other users of .previous; .pushsection and .popsection are
a safer pairing to use than .section and .previous.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-04-21 08:45:21 +01:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Rabin Vincent 22325525d8 ARM: 5868/1: ARM: fix "BUG: using smp_processor_id() in preemptible code"
Fix the following warning, which appears when the register dump for a
faulting process is printed in a kernel with SMP, DEBUG_PREEMPT, and
DEBUG_USER (with user_debug=31) enabled:

BUG: using smp_processor_id() in preemptible [00000000] code: init/1
caller is __show_regs+0x18/0x234
Backtrace:
[<c0159e5c>] (dump_backtrace+0x0/0x114) from [<c01faf30>] (dump_stack+0x18/0x1c)
 r6:c781a000 r5:c0157544 r4:00000001 r3:00000000
[<c01faf18>] (dump_stack+0x0/0x1c) from [<c01e5230>] (debug_smp_processor_id+0xc4/0xf8)
[<c01e516c>] (debug_smp_processor_id+0x0/0xf8) from [<c0157544>] (__show_regs+0x18/0x234)
 r6:c781bfb0 r5:00000000 r4:c781bfb0 r3:00000000
[<c015752c>] (__show_regs+0x0/0x234) from [<c01577a0>] (show_regs+0x40/0x50)
[<c0157760>] (show_regs+0x0/0x50) from [<c015c968>] (__do_user_fault+0x5c/0xa4)
 r4:c781c000 r3:00000000
[<c015c90c>] (__do_user_fault+0x0/0xa4) from [<c015cbe0>] (do_page_fault+0x1b4/0x1e4)
 r7:00000000 r6:00010000 r5:c781bfb0 r4:c781c000
[<c015ca2c>] (do_page_fault+0x0/0x1e4) from [<c01554c8>] (do_DataAbort+0x3c/0xa0)
[<c015548c>] (do_DataAbort+0x0/0xa0) from [<c01560c4>] (ret_from_exception+0x0/0x10)

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-01-08 16:14:29 +00:00
Russell King 797245f5da ARM: Convert VFP/Crunch/XscaleCP thread_release() to exit_thread()
This avoids races in the VFP code where the dead thread may have
state on another CPU.  By moving this code to exit_thread(), we
will be running as the thread, and therefore be running on the
current CPU.

This means that we can ensure that the only local state is accessed
in the thread notifiers.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-12-18 14:53:41 +00:00
Artem Bityutskiy cde3f86073 ARM: 5759/1: Add register information of threads to coredump
Defines ELF_CORE_COPY_TASK_REGS so that CPU register information
of every thread is included in coredump. Without this, only the faulting
thread is coredumped.

Cc: Roger Quadros <ext-roger.quadros@nokia.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-10-14 10:33:05 +01:00
Catalin Marinas b86040a59f Thumb-2: Implementation of the unified start-up and exceptions code
This patch implements the ARM/Thumb-2 unified kernel start-up and
exception handling code.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-07-24 12:32:54 +01:00
Russell King 9ccdac3662 [ARM] idle: clean up pm_idle calling, obey hlt_counter
pm_idle is used by infrastructure (eg, cpuidle) which expects architectures
to call it in a certain way.  Arrange for ARM to follow x86's lead on this
and call pm_idle() with interrupts already disabled.  However, we expect
pm_idle() to enable interrupts before it returns.

Also, OMAP wants to be able to disable hlt-ing, so allow hlt_counter to
prevent all calls to pm_idle.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-06-22 22:34:55 +01:00
Catalin Marinas feb97c3644 [ARM] 5559/1: Limit the stack unwinding caused by a kthread exit
When a kthread function returns, it branches to do_exit(). However, the
unwinding information isn't valid anymore and any stack trace caused by
do_exit() may be incorrect. This patch adds a kernel_thread_exit()
function and annotated with '.cantunwind' so that the unwinder stops
when reaching it.

Tested-by: Tony Lindgren <tony@atomide.com>

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-06-19 16:44:23 +01:00
Catalin Marinas 26584853a4 Add core support for ARMv6/v7 big-endian
Starting with ARMv6, the CPUs support the BE-8 variant of big-endian
(byte-invariant). This patch adds the core support:

- setting of the BE-8 mode via the CPSR.E register for both kernel and
  user threads
- big-endian page table walking
- REV used to rotate instructions read from memory during fault
  processing as they are still little-endian format
- Kconfig and Makefile support for BE-8. The --be8 option must be passed
  to the final linking stage to convert the instructions to
  little-endian

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-05-30 14:00:18 +01:00
Alexey Dobriyan 6f2c55b843 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>
2009-04-02 19:04:51 -07:00
Russell King be093beb60 [ARM] pass reboot command line to arch_reset()
OMAP wishes to pass state to the boot loader upon reboot in order to
instruct it whether to wait for USB-based reflashing or not.  There is
already a facility to do this via the reboot() syscall, except we ignore
the string passed to machine_restart().

This patch fixes things to pass this string to arch_reset().  This means
that we keep the reboot mode limited to telling the kernel _how_ to
perform the reboot which should be independent of what we request the
boot loader to do.

Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-03-19 16:20:24 +00:00
Catalin Marinas 2d7c11bfc9 [ARM] 5382/1: unwind: Reorganise the stacktrace support
This patch changes the walk_stacktrace and its callers for easier
integration of stack unwinding. The arch/arm/kernel/stacktrace.h file is
also moved to arch/arm/include/asm/stacktrace.h.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-12 13:21:17 +00:00
Russell King 33fa9b1328 [ARM] Convert asm/uaccess.h to linux/uaccess.h
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-06 11:35:55 +01:00
Russell King 1de765c1e9 [ARM] remove pc_pointer()
pc_pointer() was a function to mask the PC for 26-bit ARMs, which
we no longer support.  Remove it.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-06 10:35:51 +01:00
Russell King 09d9bae064 [ARM] sparse: fix several warnings
arch/arm/kernel/process.c:270:6: warning: symbol 'show_fpregs' was not declared. Should it be static?

This function isn't used, so can be removed.

arch/arm/kernel/setup.c:532:9: warning: symbol 'len' shadows an earlier one
arch/arm/kernel/setup.c:524:6: originally declared here

A function containing two 'len's.

arch/arm/mm/fault-armv.c:188:13: warning: symbol 'check_writebuffer_bugs' was not declared. Should it be static?
arch/arm/mm/mmap.c:122:5: warning: symbol 'valid_phys_addr_range' was not declared. Should it be static?
arch/arm/mm/mmap.c:137:5: warning: symbol 'valid_mmap_phys_addr_range' was not declared. Should it be static?

Missing includes.

arch/arm/kernel/traps.c:71:77: warning: Using plain integer as NULL pointer
arch/arm/mm/ioremap.c:355:46: error: incompatible types in comparison expression (different address spaces)

Sillies.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-05 14:11:24 +01:00
Russell King a09e64fbc0 [ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach
This just leaves include/asm-arm/plat-* to deal with.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-07 09:55:48 +01:00
Ingo Molnar 9b610fda0d Merge branch 'linus' into timers/nohz 2008-07-18 19:53:16 +02:00
Thomas Gleixner b8f8c3cf0a nohz: prevent tick stop outside of the idle loop
Jack Ren and Eric Miao tracked down the following long standing
problem in the NOHZ code:

	scheduler switch to idle task
	enable interrupts

Window starts here

	----> interrupt happens (does not set NEED_RESCHED)
	      	irq_exit() stops the tick

	----> interrupt happens (does set NEED_RESCHED)

	return from schedule()
	
	cpu_idle(): preempt_disable();

Window ends here

The interrupts can happen at any point inside the race window. The
first interrupt stops the tick, the second one causes the scheduler to
rerun and switch away from idle again and we end up with the tick
disabled.

The fact that it needs two interrupts where the first one does not set
NEED_RESCHED and the second one does made the bug obscure and extremly
hard to reproduce and analyse. Kudos to Jack and Eric.

Solution: Limit the NOHZ functionality to the idle loop to make sure
that we can not run into such a situation ever again.

cpu_idle()
{
	preempt_disable();

	while(1) {
		 tick_nohz_stop_sched_tick(1); <- tell NOHZ code that we
		 			          are in the idle loop

		 while (!need_resched())
		       halt();

		 tick_nohz_restart_sched_tick(); <- disables NOHZ mode
		 preempt_enable_no_resched();
		 schedule();
		 preempt_disable();
	}
}

In hindsight we should have done this forever, but ... 

/me grabs a large brown paperbag.

Debugged-by: Jack Ren <jack.ren@marvell.com>, 
Debugged-by: eric miao <eric.y.miao@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-07-18 18:10:28 +02:00
Russell King 205bee6ad8 [ARM] dyntick: Remove obsolete and unused ARM dyntick support
dyntick is superseded by the clocksource/clockevent infrastructure,
using the NO_HZ configuration option.  No one implements dyntick on
ARM anymore, so it's pointless keeping it around.  Remove dyntick
support.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-05-12 17:39:14 +01:00
David Howells 1eb1141123 aout: remove unnecessary inclusions of {asm, linux}/a.out.h
Remove now unnecessary inclusions of {asm,linux}/a.out.h.

[akpm@linux-foundation.org: fix alpha build]
Signed-off-by: David Howells <dhowells@redhat.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>
2008-02-08 09:22:30 -08:00
David Howells 7fa3031500 aout: suppress A.OUT library support if !CONFIG_ARCH_SUPPORTS_AOUT
Suppress A.OUT library support if CONFIG_ARCH_SUPPORTS_AOUT is not set.

Not all architectures support the A.OUT binfmt, so the ELF binfmt should not
be permitted to go looking for A.OUT libraries to load in such a case.  Not
only that, but under such conditions A.OUT core dumps are not produced either.

To make this work, this patch also does the following:

 (1) Makes the existence of the contents of linux/a.out.h contingent on
     CONFIG_ARCH_SUPPORTS_AOUT.

 (2) Renames dump_thread() to aout_dump_thread() as it's only called by A.OUT
     core dumping code.

 (3) Moves aout_dump_thread() into asm/a.out-core.h and makes it inline.  This
     is then included only where needed.  This means that this bit of arch
     code will be stored in the appropriate A.OUT binfmt module rather than
     the core kernel.

 (4) Drops A.OUT support for Blackfin (according to Mike Frysinger it's not
     needed) and FRV.

This patch depends on the previous patch to move STACK_TOP[_MAX] out of
asm/a.out.h and into asm/processor.h as they're required whether or not A.OUT
format is available.

[jdike@addtoit.com: uml: re-remove accidentally restored code]
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:30 -08:00
Alexey Dobriyan 19c5870c0e Use helpers to obtain task pid in printks (arch code)
One of the easiest things to isolate is the pid printed in kernel log.
There was a patch, that made this for arch-independent code, this one makes
so for arch/xxx files.

It took some time to cross-compile it, but hopefully these are all the
printks in arch code.

Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:43 -07:00
George G. Davis 909d6c6c80 [ARM] 4453/1: Fully Decode ARM instruction set state in show_regs() tombstone
The ARM show_regs() tombstone only partially decodes which ARM ISA was
executing at the time a fault occurred displaying either "(T)" for the
Thumb case or nothing at all for other cases.  This patch therefore
explicitly identifies which state the processor is in at the time of
a fault: ARM, Thumb, Jazelle or JazelleEE.

Signed-off-by: George G. Davis <gdavis@mvista.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-07-12 11:13:35 +01:00
Russell King 154c772ebf [ARM] Update show_regs/oops register format
Add the kernel release and version information to the output of
show_regs/oops.  Add the CPU PSR register.  Avoid using printk
to output partial lines; always output a complete line.

Re-combine the "Control" and "Table + DAC" lines after nommu
separated them; we don't want to waste vertical screen space
needlessly.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-06-18 15:04:42 +01:00
Kevin Hilman 9e4559ddff [ARM] 4258/2: Support for dynticks in idle loop
And, wrap timer_tick() and sysdev suspend/resume in
!GENERIC_CLOCKEVENTS since clockevent layer takes care
of these.

Signed-off-by: Kevin Hilman <khilman@mvista.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-04-21 21:02:25 +01:00
Russell King 0f0a00beb8 [ARM] Remove needless linux/ptrace.h includes
Lots of places in arch/arm were needlessly including linux/ptrace.h,
resumably because we used to pass a struct pt_regs to interrupt
handlers.  Now that we don't, all these ptrace.h includes are
redundant.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-04-21 20:34:47 +01:00
Russell King ae0a846e41 [ARM] Move processor_modes[] to .../process.c
bad_mode() currently prints the mode which caused the exception, and
then causes an oops dump to be printed which again displays this
information (since the CPSR in the struct pt_regs is correct.)  This
leads to processor_modes[] being shared between traps.c and process.c
with a local declaration of it.

We can clean this up by moving processor_modes[] to process.c and
removing the duplication, resulting in processor_modes[] becoming
static.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-02-06 16:46:48 +00:00
Paul Gortmaker 122214428a [ARM] 3911/2: Simplify alloc_thread_info on ARM
Remove ARM local cache of 4 struct thread_info.
Can cause oops under certain circumstances.

Russell indicated the original optimization was
required on older kernels to avoid thread starvation
on memory fragmentation, but may no longer be
required.  I've updated the patch to 19rc4 and
ensured no <config.h> dain-bramage slipped in this
time (sorry about that).

Original description follows:

I was given some test results which pointed to an
Oops in alloc_thread_info (happened 2x), and after
looking at the code, I see that ARM has its own
local cache of 4 struct thread_info. There wasn't
any clear (to me) synchronization between the
alloc_thread_info and the free_thread_info.

I looked over the other arch, and they all simply
allocate them on an as needed basis, so I simplified
the ARM to do the same, based on the other arch
(e.g. PPC) and the folks doing the testing have
indicated that this fixed the oops.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-11-30 15:27:03 +00:00
Hyok S. Choi f12d0d7c77 [ARM] nommu: manage the CP15 things
All the current CP15 access codes in ARM arch can be categorized and
conditioned by the defines as follows:

     Related operation	Safe condition
  a. any CP15 access	!CPU_CP15
  b. alignment trap	CPU_CP15_MMU
  c. D-cache(C-bit)	CPU_CP15
  d. I-cache		CPU_CP15 && !( CPU_ARM610 || CPU_ARM710 ||
				CPU_ARM720 || CPU_ARM740 ||
				CPU_XSCALE || CPU_XSC3 )
  e. alternate vector	CPU_CP15 && !CPU_ARM740
  f. TTB		CPU_CP15_MMU
  g. Domain		CPU_CP15_MMU
  h. FSR/FAR		CPU_CP15_MMU

For example, alternate vector is supported if and only if
"CPU_CP15 && !CPU_ARM740" is satisfied.

Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-09-27 17:34:30 +01:00
Linus Torvalds a8c4c20dfa Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (44 commits)
  [ARM] 3541/2: workaround for PXA27x erratum E7
  [ARM] nommu: provide a way for correct control register value selection
  [ARM] 3705/1: add supersection support to ioremap()
  [ARM] 3707/1: iwmmxt: use the generic thread notifier infrastructure
  [ARM] 3706/2: ep93xx: add cirrus logic edb9315a support
  [ARM] 3704/1: format IOP Kconfig with tabs, create more consistency
  [ARM] 3703/1: Add help description for ARCH_EP80219
  [ARM] 3678/1: MMC: Make OMAP MMC work
  [ARM] 3677/1: OMAP: Update H2 defconfig
  [ARM] 3676/1: ARM: OMAP: Fix dmtimers and timer32k to compile on OMAP1
  [ARM] Add section support to ioremap
  [ARM] Fix sa11x0 SDRAM selection
  [ARM] Set bit 4 on section mappings correctly depending on CPU
  [ARM] 3666/1: TRIZEPS4 [1/5] core
  ARM: OMAP: Multiplexing for 24xx GPMC wait pin monitoring
  ARM: OMAP: Fix SRAM to use MT_MEMORY instead of MT_DEVICE
  ARM: OMAP: Update dmtimers
  ARM: OMAP: Make clock variables static
  ARM: OMAP: Fix GPMC compilation when DEBUG is defined
  ARM: OMAP: Mux updates for external DMA and GPIO
  ...
2006-07-02 15:04:12 -07:00
Lennert Buytenhek ae95bfbb2b [ARM] 3707/1: iwmmxt: use the generic thread notifier infrastructure
Patch from Lennert Buytenhek

This patch makes the iWMMXt context switch hook use the generic
thread notifier infrastructure that was recently merged in commit
d6551e884c.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-07-01 19:56:48 +01:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Russell King d6551e884c [ARM] Add thread_notify infrastructure
Some machine classes need to allow VFP support to be built into the
kernel, but still allow the kernel to run even though VFP isn't
present.  Unfortunately, the kernel hard-codes VFP instructions
into the thread switch, which prevents this being run-time selectable.

Solve this by introducing a notifier which things such as VFP can
hook into to be informed of events which affect the VFP subsystem
(eg, creation and destruction of threads, switches between threads.)

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-22 10:24:18 +01:00