Something went wrong. Try again.
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Something went wrong. Try again.
3.4 kB · 133 lines
C
at master
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134/* SPDX-License-Identifier: GPL-2.0-or-later *//* * Generic C implementation of atomic counter operations. Do not include in * machine independent code. * * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */#ifndef __ASM_GENERIC_ATOMIC_H#define __ASM_GENERIC_ATOMIC_H
#include <asm/cmpxchg.h>#include <asm/barrier.h>
#ifdef CONFIG_SMP
/* we can build all atomic primitives from cmpxchg */
#define ATOMIC_OP(op, c_op) \static inline void generic_atomic_##op(int i, atomic_t *v) \{ \ int c, old; \ \ c = v->counter; \ while ((old = arch_cmpxchg(&v->counter, c, c c_op i)) != c) \ c = old; \}
#define ATOMIC_OP_RETURN(op, c_op) \static inline int generic_atomic_##op##_return(int i, atomic_t *v) \{ \ int c, old; \ \ c = v->counter; \ while ((old = arch_cmpxchg(&v->counter, c, c c_op i)) != c) \ c = old; \ \ return c c_op i; \}
#define ATOMIC_FETCH_OP(op, c_op) \static inline int generic_atomic_fetch_##op(int i, atomic_t *v) \{ \ int c, old; \ \ c = v->counter; \ while ((old = arch_cmpxchg(&v->counter, c, c c_op i)) != c) \ c = old; \ \ return c; \}
#else
#include <linux/irqflags.h>
#define ATOMIC_OP(op, c_op) \static inline void generic_atomic_##op(int i, atomic_t *v) \{ \ unsigned long flags; \ \ raw_local_irq_save(flags); \ v->counter = v->counter c_op i; \ raw_local_irq_restore(flags); \}
#define ATOMIC_OP_RETURN(op, c_op) \static inline int generic_atomic_##op##_return(int i, atomic_t *v) \{ \ unsigned long flags; \ int ret; \ \ raw_local_irq_save(flags); \ ret = (v->counter = v->counter c_op i); \ raw_local_irq_restore(flags); \ \ return ret; \}
#define ATOMIC_FETCH_OP(op, c_op) \static inline int generic_atomic_fetch_##op(int i, atomic_t *v) \{ \ unsigned long flags; \ int ret; \ \ raw_local_irq_save(flags); \ ret = v->counter; \ v->counter = v->counter c_op i; \ raw_local_irq_restore(flags); \ \ return ret; \}
#endif /* CONFIG_SMP */
ATOMIC_OP_RETURN(add, +)ATOMIC_OP_RETURN(sub, -)
ATOMIC_FETCH_OP(add, +)ATOMIC_FETCH_OP(sub, -)ATOMIC_FETCH_OP(and, &)ATOMIC_FETCH_OP(or, |)ATOMIC_FETCH_OP(xor, ^)
ATOMIC_OP(add, +)ATOMIC_OP(sub, -)ATOMIC_OP(and, &)ATOMIC_OP(or, |)ATOMIC_OP(xor, ^)
#undef ATOMIC_FETCH_OP#undef ATOMIC_OP_RETURN#undef ATOMIC_OP
#define arch_atomic_add_return generic_atomic_add_return#define arch_atomic_sub_return generic_atomic_sub_return
#define arch_atomic_fetch_add generic_atomic_fetch_add#define arch_atomic_fetch_sub generic_atomic_fetch_sub#define arch_atomic_fetch_and generic_atomic_fetch_and#define arch_atomic_fetch_or generic_atomic_fetch_or#define arch_atomic_fetch_xor generic_atomic_fetch_xor
#define arch_atomic_add generic_atomic_add#define arch_atomic_sub generic_atomic_sub#define arch_atomic_and generic_atomic_and#define arch_atomic_or generic_atomic_or#define arch_atomic_xor generic_atomic_xor
#define arch_atomic_read(v) READ_ONCE((v)->counter)#define arch_atomic_set(v, i) WRITE_ONCE(((v)->counter), (i))
#endif /* __ASM_GENERIC_ATOMIC_H */