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/* 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 ([email protected])
*/
#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 */
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