2009-05-13 16:56:35 -06:00
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/*
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2011-07-26 17:09:08 -06:00
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* Generic C implementation of atomic counter operations. Usable on
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* UP systems only. Do not include in machine independent code.
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*
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2009-05-13 16:56:35 -06:00
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public Licence
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* as published by the Free Software Foundation; either version
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* 2 of the Licence, or (at your option) any later version.
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*/
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#ifndef __ASM_GENERIC_ATOMIC_H
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#define __ASM_GENERIC_ATOMIC_H
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2012-03-28 11:30:03 -06:00
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#include <asm/cmpxchg.h>
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arch: Prepare for smp_mb__{before,after}_atomic()
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>
2014-02-06 10:16:07 -07:00
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#include <asm/barrier.h>
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2012-03-28 11:30:03 -06:00
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2014-04-23 08:12:30 -06:00
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/*
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* atomic_$op() - $op integer to atomic variable
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* @i: integer value to $op
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* @v: pointer to the atomic variable
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*
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* Atomically $ops @i to @v. Does not strictly guarantee a memory-barrier, use
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* smp_mb__{before,after}_atomic().
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*/
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/*
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* atomic_$op_return() - $op interer to atomic variable and returns the result
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* @i: integer value to $op
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* @v: pointer to the atomic variable
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*
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* Atomically $ops @i to @v. Does imply a full memory barrier.
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*/
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2009-05-13 16:56:35 -06:00
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#ifdef CONFIG_SMP
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2014-04-23 08:12:30 -06:00
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/* we can build all atomic primitives from cmpxchg */
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#define ATOMIC_OP(op, c_op) \
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static inline void atomic_##op(int i, atomic_t *v) \
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{ \
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int c, old; \
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\
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c = v->counter; \
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while ((old = cmpxchg(&v->counter, c, c c_op i)) != c) \
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c = old; \
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}
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#define ATOMIC_OP_RETURN(op, c_op) \
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static inline int atomic_##op##_return(int i, atomic_t *v) \
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{ \
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int c, old; \
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\
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c = v->counter; \
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while ((old = cmpxchg(&v->counter, c, c c_op i)) != c) \
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c = old; \
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\
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return c c_op i; \
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}
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locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
Now that all the architectures have implemented support for these new
atomic primitives add on the generic infrastructure to expose and use
it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-17 16:54:38 -06:00
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#define ATOMIC_FETCH_OP(op, c_op) \
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static inline int atomic_fetch_##op(int i, atomic_t *v) \
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{ \
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int c, old; \
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\
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c = v->counter; \
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while ((old = cmpxchg(&v->counter, c, c c_op i)) != c) \
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c = old; \
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\
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return c; \
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}
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2014-04-23 08:12:30 -06:00
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#else
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#include <linux/irqflags.h>
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#define ATOMIC_OP(op, c_op) \
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static inline void atomic_##op(int i, atomic_t *v) \
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{ \
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unsigned long flags; \
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\
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raw_local_irq_save(flags); \
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v->counter = v->counter c_op i; \
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raw_local_irq_restore(flags); \
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}
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#define ATOMIC_OP_RETURN(op, c_op) \
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static inline int atomic_##op##_return(int i, atomic_t *v) \
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{ \
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unsigned long flags; \
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int ret; \
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\
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raw_local_irq_save(flags); \
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ret = (v->counter = v->counter c_op i); \
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raw_local_irq_restore(flags); \
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\
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return ret; \
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}
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locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
Now that all the architectures have implemented support for these new
atomic primitives add on the generic infrastructure to expose and use
it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-17 16:54:38 -06:00
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#define ATOMIC_FETCH_OP(op, c_op) \
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static inline int atomic_fetch_##op(int i, atomic_t *v) \
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{ \
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unsigned long flags; \
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int ret; \
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\
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raw_local_irq_save(flags); \
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ret = v->counter; \
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v->counter = v->counter c_op i; \
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raw_local_irq_restore(flags); \
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\
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return ret; \
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}
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2014-04-23 08:12:30 -06:00
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#endif /* CONFIG_SMP */
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#ifndef atomic_add_return
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ATOMIC_OP_RETURN(add, +)
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#endif
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#ifndef atomic_sub_return
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ATOMIC_OP_RETURN(sub, -)
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#endif
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locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
Now that all the architectures have implemented support for these new
atomic primitives add on the generic infrastructure to expose and use
it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-17 16:54:38 -06:00
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#ifndef atomic_fetch_add
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ATOMIC_FETCH_OP(add, +)
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#endif
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#ifndef atomic_fetch_sub
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ATOMIC_FETCH_OP(sub, -)
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#endif
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#ifndef atomic_fetch_and
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ATOMIC_FETCH_OP(and, &)
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#endif
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#ifndef atomic_fetch_or
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ATOMIC_FETCH_OP(or, |)
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#endif
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#ifndef atomic_fetch_xor
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ATOMIC_FETCH_OP(xor, ^)
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#endif
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2015-07-15 07:47:25 -06:00
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#ifndef atomic_and
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2014-04-23 08:12:30 -06:00
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ATOMIC_OP(and, &)
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2015-07-15 07:47:25 -06:00
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#endif
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#ifndef atomic_or
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2014-04-23 08:12:30 -06:00
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ATOMIC_OP(or, |)
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2015-07-15 07:47:25 -06:00
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#endif
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2014-04-23 11:32:50 -06:00
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#ifndef atomic_xor
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ATOMIC_OP(xor, ^)
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2014-04-23 08:12:30 -06:00
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#endif
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locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
Now that all the architectures have implemented support for these new
atomic primitives add on the generic infrastructure to expose and use
it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-17 16:54:38 -06:00
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#undef ATOMIC_FETCH_OP
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2014-04-23 08:12:30 -06:00
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#undef ATOMIC_OP_RETURN
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#undef ATOMIC_OP
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2009-05-13 16:56:35 -06:00
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/*
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* Atomic operations that C can't guarantee us. Useful for
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* resource counting etc..
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*/
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#define ATOMIC_INIT(i) { (i) }
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/**
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* atomic_read - read atomic variable
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* @v: pointer of type atomic_t
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*
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2010-05-24 15:33:09 -06:00
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* Atomically reads the value of @v.
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2009-05-13 16:56:35 -06:00
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*/
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2011-07-26 17:09:11 -06:00
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#ifndef atomic_read
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2015-09-18 03:13:10 -06:00
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#define atomic_read(v) READ_ONCE((v)->counter)
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2011-07-26 17:09:11 -06:00
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#endif
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2009-05-13 16:56:35 -06:00
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/**
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* atomic_set - set atomic variable
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* @v: pointer of type atomic_t
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* @i: required value
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*
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2010-05-24 15:33:09 -06:00
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* Atomically sets the value of @v to @i.
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2009-05-13 16:56:35 -06:00
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*/
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2015-09-18 03:13:10 -06:00
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#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i))
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2009-05-13 16:56:35 -06:00
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2010-10-07 07:08:55 -06:00
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#include <linux/irqflags.h>
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2009-05-13 16:56:35 -06:00
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static inline void atomic_add(int i, atomic_t *v)
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{
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atomic_add_return(i, v);
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}
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static inline void atomic_sub(int i, atomic_t *v)
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{
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atomic_sub_return(i, v);
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}
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2010-06-27 04:26:06 -06:00
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#define atomic_xchg(ptr, v) (xchg(&(ptr)->counter, (v)))
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#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
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2009-05-13 16:56:35 -06:00
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#endif /* __ASM_GENERIC_ATOMIC_H */
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