projects / mirror_ubuntu-bionic-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 6006c0d8 JH |
2 | #ifndef __ASM_METAG_ATOMIC_LOCK1_H |
| 3 | #define __ASM_METAG_ATOMIC_LOCK1_H | |
| 4 | ||
| 5 | #define ATOMIC_INIT(i) { (i) } | |
| 6 | ||
| 7 | #include <linux/compiler.h> | |
| 8 | ||
| 9 | #include <asm/barrier.h> | |
| 10 | #include <asm/global_lock.h> | |
| 11 | ||
| 12 | static inline int atomic_read(const atomic_t *v) | |
| 13 | { | |
| 62e8a325 | 14 | return READ_ONCE((v)->counter); |
| 6006c0d8 JH |
15 | } |
| 16 | ||
| 17 | /* | |
| 18 | * atomic_set needs to be take the lock to protect atomic_add_unless from a | |
| 19 | * possible race, as it reads the counter twice: | |
| 20 | * | |
| 21 | * CPU0 CPU1 | |
| 22 | * atomic_add_unless(1, 0) | |
| 23 | * ret = v->counter (non-zero) | |
| 24 | * if (ret != u) v->counter = 0 | |
| 25 | * v->counter += 1 (counter set to 1) | |
| 26 | * | |
| 27 | * Making atomic_set take the lock ensures that ordering and logical | |
| 28 | * consistency is preserved. | |
| 29 | */ | |
| 30 | static inline int atomic_set(atomic_t *v, int i) | |
| 31 | { | |
| 32 | unsigned long flags; | |
| 33 | ||
| 34 | __global_lock1(flags); | |
| 35 | fence(); | |
| 36 | v->counter = i; | |
| 37 | __global_unlock1(flags); | |
| 38 | return i; | |
| 39 | } | |
| 40 | ||
| 9d664c0a PZ |
41 | #define atomic_set_release(v, i) atomic_set((v), (i)) |
| 42 | ||
| d6dfe250 PZ |
43 | #define ATOMIC_OP(op, c_op) \ |
| 44 | static inline void atomic_##op(int i, atomic_t *v) \ | |
| 45 | { \ | |
| 46 | unsigned long flags; \ | |
| 47 | \ | |
| 48 | __global_lock1(flags); \ | |
| 49 | fence(); \ | |
| 50 | v->counter c_op i; \ | |
| 51 | __global_unlock1(flags); \ | |
| 52 | } \ | |
| 53 | ||
| 54 | #define ATOMIC_OP_RETURN(op, c_op) \ | |
| 55 | static inline int atomic_##op##_return(int i, atomic_t *v) \ | |
| 56 | { \ | |
| 57 | unsigned long result; \ | |
| 58 | unsigned long flags; \ | |
| 59 | \ | |
| 60 | __global_lock1(flags); \ | |
| 61 | result = v->counter; \ | |
| 62 | result c_op i; \ | |
| 63 | fence(); \ | |
| 64 | v->counter = result; \ | |
| 65 | __global_unlock1(flags); \ | |
| 66 | \ | |
| 67 | return result; \ | |
| 6006c0d8 JH |
68 | } |
| 69 | ||
| e898eb27 PZ |
70 | #define ATOMIC_FETCH_OP(op, c_op) \ |
| 71 | static inline int atomic_fetch_##op(int i, atomic_t *v) \ | |
| 72 | { \ | |
| 73 | unsigned long result; \ | |
| 74 | unsigned long flags; \ | |
| 75 | \ | |
| 76 | __global_lock1(flags); \ | |
| 77 | result = v->counter; \ | |
| 78 | fence(); \ | |
| 79 | v->counter c_op i; \ | |
| 80 | __global_unlock1(flags); \ | |
| 81 | \ | |
| 82 | return result; \ | |
| 83 | } | |
| 84 | ||
| 85 | #define ATOMIC_OPS(op, c_op) \ | |
| 86 | ATOMIC_OP(op, c_op) \ | |
| 87 | ATOMIC_OP_RETURN(op, c_op) \ | |
| 88 | ATOMIC_FETCH_OP(op, c_op) | |
| 6006c0d8 | 89 | |
| d6dfe250 PZ |
90 | ATOMIC_OPS(add, +=) |
| 91 | ATOMIC_OPS(sub, -=) | |
| 6006c0d8 | 92 | |
| d6dfe250 | 93 | #undef ATOMIC_OPS |
| e898eb27 PZ |
94 | #define ATOMIC_OPS(op, c_op) \ |
| 95 | ATOMIC_OP(op, c_op) \ | |
| 96 | ATOMIC_FETCH_OP(op, c_op) | |
| 97 | ||
| 98 | ATOMIC_OPS(and, &=) | |
| 99 | ATOMIC_OPS(or, |=) | |
| 100 | ATOMIC_OPS(xor, ^=) | |
| 101 | ||
| 102 | #undef ATOMIC_OPS | |
| 103 | #undef ATOMIC_FETCH_OP | |
| d6dfe250 PZ |
104 | #undef ATOMIC_OP_RETURN |
| 105 | #undef ATOMIC_OP | |
| 6006c0d8 | 106 | |
| 6006c0d8 JH |
107 | static inline int atomic_cmpxchg(atomic_t *v, int old, int new) |
| 108 | { | |
| 109 | int ret; | |
| 110 | unsigned long flags; | |
| 111 | ||
| 112 | __global_lock1(flags); | |
| 113 | ret = v->counter; | |
| 114 | if (ret == old) { | |
| 115 | fence(); | |
| 116 | v->counter = new; | |
| 117 | } | |
| 118 | __global_unlock1(flags); | |
| 119 | ||
| 120 | return ret; | |
| 121 | } | |
| 122 | ||
| 123 | #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) | |
| 124 | ||
| 125 | static inline int __atomic_add_unless(atomic_t *v, int a, int u) | |
| 126 | { | |
| 127 | int ret; | |
| 128 | unsigned long flags; | |
| 129 | ||
| 130 | __global_lock1(flags); | |
| 131 | ret = v->counter; | |
| 132 | if (ret != u) { | |
| 133 | fence(); | |
| 134 | v->counter += a; | |
| 135 | } | |
| 136 | __global_unlock1(flags); | |
| 137 | ||
| 138 | return ret; | |
| 139 | } | |
| 140 | ||
| 141 | static inline int atomic_sub_if_positive(int i, atomic_t *v) | |
| 142 | { | |
| 143 | int ret; | |
| 144 | unsigned long flags; | |
| 145 | ||
| 146 | __global_lock1(flags); | |
| 147 | ret = v->counter - 1; | |
| 148 | if (ret >= 0) { | |
| 149 | fence(); | |
| 150 | v->counter = ret; | |
| 151 | } | |
| 152 | __global_unlock1(flags); | |
| 153 | ||
| 154 | return ret; | |
| 155 | } | |
| 156 | ||
| 157 | #endif /* __ASM_METAG_ATOMIC_LOCK1_H */ |