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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))
- #define arch_atomic_xchg(ptr, v) (arch_xchg(&(ptr)->counter, (v)))
- #define arch_atomic_cmpxchg(v, old, new) (arch_cmpxchg(&((v)->counter), (old), (new)))
- #endif /* __ASM_GENERIC_ATOMIC_H */
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