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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485/* SPDX-License-Identifier: GPL-2.0 *//* Atomic operations usable in machine independent code */#ifndef _LINUX_ATOMIC_H#define _LINUX_ATOMIC_H#include <linux/types.h>
#include <asm/atomic.h>#include <asm/barrier.h>
/* * Relaxed variants of xchg, cmpxchg and some atomic operations. * * We support four variants: * * - Fully ordered: The default implementation, no suffix required. * - Acquire: Provides ACQUIRE semantics, _acquire suffix. * - Release: Provides RELEASE semantics, _release suffix. * - Relaxed: No ordering guarantees, _relaxed suffix. * * For compound atomics performing both a load and a store, ACQUIRE * semantics apply only to the load and RELEASE semantics only to the * store portion of the operation. Note that a failed cmpxchg_acquire * does -not- imply any memory ordering constraints. * * See Documentation/memory-barriers.txt for ACQUIRE/RELEASE definitions. */
#define atomic_cond_read_acquire(v, c) smp_cond_load_acquire(&(v)->counter, (c))#define atomic_cond_read_relaxed(v, c) smp_cond_load_relaxed(&(v)->counter, (c))
#define atomic64_cond_read_acquire(v, c) smp_cond_load_acquire(&(v)->counter, (c))#define atomic64_cond_read_relaxed(v, c) smp_cond_load_relaxed(&(v)->counter, (c))
/* * The idea here is to build acquire/release variants by adding explicit * barriers on top of the relaxed variant. In the case where the relaxed * variant is already fully ordered, no additional barriers are needed. * * If an architecture overrides __atomic_acquire_fence() it will probably * want to define smp_mb__after_spinlock(). */#ifndef __atomic_acquire_fence#define __atomic_acquire_fence smp_mb__after_atomic#endif
#ifndef __atomic_release_fence#define __atomic_release_fence smp_mb__before_atomic#endif
#ifndef __atomic_pre_full_fence#define __atomic_pre_full_fence smp_mb__before_atomic#endif
#ifndef __atomic_post_full_fence#define __atomic_post_full_fence smp_mb__after_atomic#endif
#define __atomic_op_acquire(op, args...) \({ \ typeof(op##_relaxed(args)) __ret = op##_relaxed(args); \ __atomic_acquire_fence(); \ __ret; \})
#define __atomic_op_release(op, args...) \({ \ __atomic_release_fence(); \ op##_relaxed(args); \})
#define __atomic_op_fence(op, args...) \({ \ typeof(op##_relaxed(args)) __ret; \ __atomic_pre_full_fence(); \ __ret = op##_relaxed(args); \ __atomic_post_full_fence(); \ __ret; \})
#include <linux/atomic/atomic-arch-fallback.h>#include <linux/atomic/atomic-long.h>#include <linux/atomic/atomic-instrumented.h>
#endif /* _LINUX_ATOMIC_H */