/* 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 */