Use the much more reader friendly ACCESS_ONCE() instead of the cast to volatile.
This is purely a stylistic change.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
Link: http://lkml.kernel.org/r/1411482607-20948-1-git-send-email-bobby.prani@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Rewrite generic atomic support to only require cmpxchg(), generate all
other primitives from that.
Furthermore reduce the endless repetition for all these primitives to
a few CPP macros. This way we get more for less lines.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140508135852.940119622@infradead.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Since the smp_mb__{before,after}*() ops are fundamentally dependent on
how an arch can implement atomics it doesn't make sense to have 3
variants of them. They must all be the same.
Furthermore, the 3 variants suggest they're only valid for those 3
atomic ops, while we have many more where they could be applied.
So move away from
smp_mb__{before,after}_{atomic,clear}_{dec,inc,bit}() and reduce the
interface to just the two: smp_mb__{before,after}_atomic().
This patch prepares the way by introducing default implementations in
asm-generic/barrier.h that default to a full barrier and providing
__deprecated inlines for the previous 6 barriers if they're not
provided by the arch.
This should allow for a mostly painless transition (lots of deprecated
warns in the interim).
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-wr59327qdyi9mbzn6x937s4e@git.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Chen, Gong" <gong.chen@linux.intel.com>
Cc: John Sullivan <jsrhbz@kanargh.force9.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
asm/cmpxchg.h can be included on its own and needs to be self-consistent.
The definitions for the cmpxchg*_local macros, as such, need to be part
of this file.
This fixes a build issue on OpenRISC since the system.h smashing patch
96f951edb1 that introdued the direct inclusion
asm/cmpxchg.h into linux/llist.h.
CC: David Howells <dhowells@redhat.com>
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Remove all #inclusions of asm/system.h preparatory to splitting and killing
it. Performed with the following command:
perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`
Signed-off-by: David Howells <dhowells@redhat.com>
Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h as all arch
files that #include the former also #include the latter. See:
grep -rl asm-generic/cmpxchg-local[.]h arch/ | sort > b
grep -rl asm-generic/cmpxchg[.]h arch/ | sort > a
comm a b
This simplifies the disintegration of asm-generic/system.h for arches that
don't have their own.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Only a few core funcs need to be implemented for SMP systems, so allow the
arches to override them while getting the rest for free.
At least, this is enough to allow the Blackfin SMP port to use things.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Arun Sharma <asharma@fb.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since arches are expected to implement this guy, add a common version for
people the same way as atomic_clear_mask is handled.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Arun Sharma <asharma@fb.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The atomic helpers are supposed to take an atomic_t pointer, not a random
unsigned long pointer. So convert atomic_clear_mask over.
While we're here, also add some nice documentation to the func.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Arun Sharma <asharma@fb.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We already declared inc/dec helpers, so we don't need to call the
atomic_{add,sub}_return funcs directly.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Arun Sharma <asharma@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This clarifies the differences between <linux/atomic.h> and
<asm-generic/atomic.h>
Signed-off-by: Arun Sharma <asharma@fb.com>
Suggested-by: Mike Frysinger <vapier.adi@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After changing all consumers of atomics to include <linux/atomic.h>, we
ran into some compile time errors due to this dependency chain:
linux/atomic.h
-> asm/atomic.h
-> asm-generic/atomic-long.h
where atomic-long.h could use funcs defined later in linux/atomic.h
without a prototype. This patches moves the code that includes
asm-generic/atomic*.h to linux/atomic.h.
Archs that need <asm-generic/atomic64.h> need to select
CONFIG_GENERIC_ATOMIC64 from now on (some of them used to include it
unconditionally).
Compile tested on i386 and x86_64 with allnoconfig.
Signed-off-by: Arun Sharma <asharma@fb.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is in preparation for more generic atomic primitives based on
__atomic_add_unless.
Signed-off-by: Arun Sharma <asharma@fb.com>
Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
asm-generic/io.h: allow people to override individual funcs
bitops: remove duplicated extern declarations
bitops: make asm-generic/bitops/find.h more generic
asm-generic: kdebug.h: Checkpatch cleanup
asm-generic: fcntl: make exported headers use strict posix types
asm-generic: cmpxchg does not handle non-long arguments
asm-generic: make atomic_add_unless a function
atomic_add_unless is a macro so, bad things happen if the caller defines
a local variable named c, just like like the local variable c defined by
the macro. Thus, convert atomic_add_unless to a function. (bug triggered
by net/ipv4/netfilter/ipt_CLUSTERIP.c: clusterip_config_find_get calls
atomic_inc_not_zero)
Signed-off-by: Mathieu Lacage <mathieu.lacage@inria.fr>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fix the IRQ flag handling naming. In linux/irqflags.h under one configuration,
it maps:
local_irq_enable() -> raw_local_irq_enable()
local_irq_disable() -> raw_local_irq_disable()
local_irq_save() -> raw_local_irq_save()
...
and under the other configuration, it maps:
raw_local_irq_enable() -> local_irq_enable()
raw_local_irq_disable() -> local_irq_disable()
raw_local_irq_save() -> local_irq_save()
...
This is quite confusing. There should be one set of names expected of the
arch, and this should be wrapped to give another set of names that are expected
by users of this facility.
Change this to have the arch provide:
flags = arch_local_save_flags()
flags = arch_local_irq_save()
arch_local_irq_restore(flags)
arch_local_irq_disable()
arch_local_irq_enable()
arch_irqs_disabled_flags(flags)
arch_irqs_disabled()
arch_safe_halt()
Then linux/irqflags.h wraps these to provide:
raw_local_save_flags(flags)
raw_local_irq_save(flags)
raw_local_irq_restore(flags)
raw_local_irq_disable()
raw_local_irq_enable()
raw_irqs_disabled_flags(flags)
raw_irqs_disabled()
raw_safe_halt()
with type checking on the flags 'arguments', and then wraps those to provide:
local_save_flags(flags)
local_irq_save(flags)
local_irq_restore(flags)
local_irq_disable()
local_irq_enable()
irqs_disabled_flags(flags)
irqs_disabled()
safe_halt()
with tracing included if enabled.
The arch functions can now all be inline functions rather than some of them
having to be macros.
Signed-off-by: David Howells <dhowells@redhat.com> [X86, FRV, MN10300]
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> [Tile]
Signed-off-by: Michal Simek <monstr@monstr.eu> [Microblaze]
Tested-by: Catalin Marinas <catalin.marinas@arm.com> [ARM]
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> [AVR]
Acked-by: Tony Luck <tony.luck@intel.com> [IA-64]
Acked-by: Hirokazu Takata <takata@linux-m32r.org> [M32R]
Acked-by: Greg Ungerer <gerg@uclinux.org> [M68K/M68KNOMMU]
Acked-by: Ralf Baechle <ralf@linux-mips.org> [MIPS]
Acked-by: Kyle McMartin <kyle@mcmartin.ca> [PA-RISC]
Acked-by: Paul Mackerras <paulus@samba.org> [PowerPC]
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [S390]
Acked-by: Chen Liqin <liqin.chen@sunplusct.com> [Score]
Acked-by: Matt Fleming <matt@console-pimps.org> [SH]
Acked-by: David S. Miller <davem@davemloft.net> [Sparc]
Acked-by: Chris Zankel <chris@zankel.net> [Xtensa]
Reviewed-by: Richard Henderson <rth@twiddle.net> [Alpha]
Reviewed-by: Yoshinori Sato <ysato@users.sourceforge.jp> [H8300]
Cc: starvik@axis.com [CRIS]
Cc: jesper.nilsson@axis.com [CRIS]
Cc: linux-cris-kernel@axis.com
The start/stop_critical_timing functions for preemptirqsoff, preemptoff
and irqsoff tracers contain atomic_inc() and atomic_dec() operations.
Atomic operations use local_irq_save/restore macros to ensure atomic
access but they are traced by the same function which is causing recursion
problem.
The reason is when these tracers are turn ON then the
local_irq_save/restore macros are changed in include/linux/irqflags.h to
call trace_hardirqs_on/off which call start/stop_critical_timing.
Microblaze was affected because it uses generic atomic implementation.
Signed-off-by: Michal Simek <monstr@monstr.eu>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
32-bit Sparc used to only allow usage of 24-bit of it's atomic_t type.
This was corrected with linux 2.6.3 when Keith M Wesolowski changed the
implementation to use the parisc approach of having an array of spinlocks
to protect the atomic_t.
These warnings were also removed from the sparc implementation when the
new implementation was merged in BKrev:402e4949VThdc6D3iaosSFUgabMfvw, but
the warning still remained in some other places without any 24-bit-only
atomic_t implementation inside the kernel.
We should remove these warnings to allow users to rely on the full 32-bit
range of atomic_t.
Signed-off-by: Peter Fritzsche <peter.fritzsche@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In preparation for removing volatile from the atomic_t definition, this
patch adds a volatile cast to all the atomic read functions.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
atomic.h and io.h are based on the mn10300 architecture,
which is already pretty generic and can be used by
other architectures that do not have hardware support
for atomic operations or out-of-order I/O access.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The existing asm-generic/atomic.h only defines the
atomic_long type. This renames it to atomic-long.h
so we have a place to add a truly generic atomic.h
that can be used on all non-SMP systems.
Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
On a linux-next allyesconfig build:
kernel/trace/ring_buffer.c:1726:
warning: passing argument 1 of 'atomic_cmpxchg' from incompatible pointer type
linux-next/arch/s390/include/asm/atomic.h:112:
note: expected 'struct atomic_t *' but argument is of type 'struct atomic64_t *'
atomic_long_cmpxchg and atomic_long_xchg are incorrectly defined for 64
bit architectures. They should be mapped to the atomic64_* variants.
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
atomic_long_xchg() is not correctly defined for 32bit arches.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove all clameter@sgi.com addresses from the kernel tree since they will
become invalid on June 27th. Change my maintainer email address for the
slab allocators to cl@linux-foundation.org (which will be the new email
address for the future).
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
atomic_add_unless as inline. Remove system.h atomic.h circular dependency.
I agree (with Andi Kleen) this typeof is not needed and more error
prone. All the original atomic.h code that uses cmpxchg (which includes
the atomic_add_unless) uses defines instead of inline functions,
probably to circumvent a circular dependency between system.h and
atomic.h on powerpc (which my patch addresses). Therefore, it makes
sense to use inline functions that will provide type checking.
atomic_add_unless as inline. Remove system.h atomic.h circular dependency.
Digging into the FRV architecture shows me that it is also affected by
such a circular dependency. Here is the diff applying this against the
rest of my atomic.h patches.
It applies over the atomic.h standardization patches.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For some reason, the BITS_PER_LONG == 64 case of atomic_long_set
was using atomic_set instead of atomic64_set. This does not jive
with architectures which use an inline instead of a #define to
implement their atomic_set() primitives.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Several counters already have the need to use 64 atomic variables on 64 bit
platforms (see mm_counter_t in sched.h). We have to do ugly ifdefs to fall
back to 32 bit atomic on 32 bit platforms.
The VM statistics patch that I am working on will also make more extensive
use of atomic64.
This patch introduces a new type atomic_long_t by providing definitions in
asm-generic/atomic.h that works similar to the c "long" type. Its 32 bits
on 32 bit platforms and 64 bits on 64 bit platforms.
Also cleans up the determination of the mm_counter_t in sched.h.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
