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
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>
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
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
...
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>
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>
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
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
...
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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
...
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
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>
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
...
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>
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>
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>
* '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.
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Linus Torvalds
Al Viro
Nicolas Pitre
fwu
Arnd Bergmann
Bryan Wu
Shawn Guo
Thomas Gleixner
David Howells
Russell King
Will Deacon
Jason Baron
Frederic Weisbecker
Paul Gortmaker
Laura Abbott
David Brown
Len Brown
Catalin Marinas
Kevin Hilman
Nicolas Pitre