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Diffstat (limited to 'include/asm-generic/atomic.h')
| -rw-r--r-- | include/asm-generic/atomic.h | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/include/asm-generic/atomic.h b/include/asm-generic/atomic.h new file mode 100644 index 0000000000..22142c71d3 --- /dev/null +++ b/include/asm-generic/atomic.h @@ -0,0 +1,133 @@ +/* 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 */ |