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