| 1 |
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| 2 | |
| 3 | * Generic C implementation of atomic counter operations. Do not include in
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| 4 | * machine independent code.
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| 5 | *
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| 6 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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| 7 | * Written by David Howells ([email protected])
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| 8 |
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| 9 | #ifndef __ASM_GENERIC_ATOMIC_H
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| 10 | #define __ASM_GENERIC_ATOMIC_H
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| 11 |
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| 12 | #include <asm/cmpxchg.h>
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| 13 | #include <asm/barrier.h>
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| 14 |
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| 15 | #ifdef CONFIG_SMP
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| 16 |
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| 17 |
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| 18 |
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| 19 | #define ATOMIC_OP(op, c_op) \
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| 20 | static inline void generic_atomic_##op(int i, atomic_t *v) \
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| 21 | { \
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| 22 | int c, old; \
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| 23 | \
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| 24 | c = v->counter; \
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| 25 | while ((old = arch_cmpxchg(&v->counter, c, c c_op i)) != c) \
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| 26 | c = old; \
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| 27 | }
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| 28 |
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| 29 | #define ATOMIC_OP_RETURN(op, c_op) \
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| 30 | static inline int generic_atomic_##op##_return(int i, atomic_t *v) \
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| 31 | { \
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| 32 | int c, old; \
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| 33 | \
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| 34 | c = v->counter; \
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| 35 | while ((old = arch_cmpxchg(&v->counter, c, c c_op i)) != c) \
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| 36 | c = old; \
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| 37 | \
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| 38 | return c c_op i; \
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| 39 | }
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| 40 |
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| 41 | #define ATOMIC_FETCH_OP(op, c_op) \
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| 42 | static inline int generic_atomic_fetch_##op(int i, atomic_t *v) \
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| 43 | { \
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| 44 | int c, old; \
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| 45 | \
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| 46 | c = v->counter; \
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| 47 | while ((old = arch_cmpxchg(&v->counter, c, c c_op i)) != c) \
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| 48 | c = old; \
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| 49 | \
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| 50 | return c; \
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| 51 | }
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| 52 |
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| 53 | #else
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| 54 |
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| 55 | #include <linux/irqflags.h>
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| 56 |
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| 57 | #define ATOMIC_OP(op, c_op) \
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| 58 | static inline void generic_atomic_##op(int i, atomic_t *v) \
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| 59 | { \
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| 60 | unsigned long flags; \
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| 61 | \
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| 62 | raw_local_irq_save(flags); \
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| 63 | v->counter = v->counter c_op i; \
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| 64 | raw_local_irq_restore(flags); \
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| 65 | }
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| 66 |
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| 67 | #define ATOMIC_OP_RETURN(op, c_op) \
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| 68 | static inline int generic_atomic_##op##_return(int i, atomic_t *v) \
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| 69 | { \
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| 70 | unsigned long flags; \
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| 71 | int ret; \
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| 72 | \
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| 73 | raw_local_irq_save(flags); \
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| 74 | ret = (v->counter = v->counter c_op i); \
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| 75 | raw_local_irq_restore(flags); \
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| 76 | \
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| 77 | return ret; \
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| 78 | }
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| 79 |
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| 80 | #define ATOMIC_FETCH_OP(op, c_op) \
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| 81 | static inline int generic_atomic_fetch_##op(int i, atomic_t *v) \
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| 82 | { \
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| 83 | unsigned long flags; \
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| 84 | int ret; \
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| 85 | \
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| 86 | raw_local_irq_save(flags); \
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| 87 | ret = v->counter; \
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| 88 | v->counter = v->counter c_op i; \
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| 89 | raw_local_irq_restore(flags); \
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| 90 | \
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| 91 | return ret; \
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| 92 | }
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| 93 |
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| 94 | #endif
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| 95 |
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| 96 | ATOMIC_OP_RETURN(add, +)
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| 97 | ATOMIC_OP_RETURN(sub, -)
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| 98 |
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| 99 | ATOMIC_FETCH_OP(add, +)
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| 100 | ATOMIC_FETCH_OP(sub, -)
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| 101 | ATOMIC_FETCH_OP(and, &)
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| 102 | ATOMIC_FETCH_OP(or, |)
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| 103 | ATOMIC_FETCH_OP(xor, ^)
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| 104 |
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| 105 | ATOMIC_OP(add, +)
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| 106 | ATOMIC_OP(sub, -)
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| 107 | ATOMIC_OP(and, &)
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| 108 | ATOMIC_OP(or, |)
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| 109 | ATOMIC_OP(xor, ^)
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| 110 |
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| 111 | #undef ATOMIC_FETCH_OP
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| 112 | #undef ATOMIC_OP_RETURN
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| 113 | #undef ATOMIC_OP
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| 114 |
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| 115 | #define arch_atomic_add_return generic_atomic_add_return
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| 116 | #define arch_atomic_sub_return generic_atomic_sub_return
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| 117 |
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| 118 | #define arch_atomic_fetch_add generic_atomic_fetch_add
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| 119 | #define arch_atomic_fetch_sub generic_atomic_fetch_sub
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| 120 | #define arch_atomic_fetch_and generic_atomic_fetch_and
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| 121 | #define arch_atomic_fetch_or generic_atomic_fetch_or
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| 122 | #define arch_atomic_fetch_xor generic_atomic_fetch_xor
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| 123 |
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| 124 | #define arch_atomic_add generic_atomic_add
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| 125 | #define arch_atomic_sub generic_atomic_sub
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| 126 | #define arch_atomic_and generic_atomic_and
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| 127 | #define arch_atomic_or generic_atomic_or
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| 128 | #define arch_atomic_xor generic_atomic_xor
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| 129 |
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| 130 | #define arch_atomic_read(v) READ_ONCE((v)->counter)
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| 131 | #define arch_atomic_set(v, i) WRITE_ONCE(((v)->counter), (i))
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| 132 |
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| 133 | #endif
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