| 1 | /* |
| 2 | * Copyright (C) 2010 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #ifndef ANDROID_CUTILS_ATOMIC_X86_H |
| 18 | #define ANDROID_CUTILS_ATOMIC_X86_H |
| 19 | |
| 20 | #include <stdint.h> |
| 21 | |
| 22 | extern inline void android_compiler_barrier(void) |
| 23 | { |
| 24 | __asm__ __volatile__ ("" : : : "memory"); |
| 25 | } |
| 26 | |
| 27 | #if ANDROID_SMP == 0 |
| 28 | extern inline void android_memory_barrier(void) |
| 29 | { |
| 30 | android_compiler_barrier(); |
| 31 | } |
| 32 | extern inline void android_memory_store_barrier(void) |
| 33 | { |
| 34 | android_compiler_barrier(); |
| 35 | } |
| 36 | #else |
| 37 | extern inline void android_memory_barrier(void) |
| 38 | { |
| 39 | __asm__ __volatile__ ("mfence" : : : "memory"); |
| 40 | } |
| 41 | extern inline void android_memory_store_barrier(void) |
| 42 | { |
| 43 | android_compiler_barrier(); |
| 44 | } |
| 45 | #endif |
| 46 | |
| 47 | extern inline int32_t android_atomic_acquire_load(volatile const int32_t *ptr) |
| 48 | { |
| 49 | int32_t value = *ptr; |
| 50 | android_compiler_barrier(); |
| 51 | return value; |
| 52 | } |
| 53 | |
| 54 | extern inline int32_t android_atomic_release_load(volatile const int32_t *ptr) |
| 55 | { |
| 56 | android_memory_barrier(); |
| 57 | return *ptr; |
| 58 | } |
| 59 | |
| 60 | extern inline void android_atomic_acquire_store(int32_t value, |
| 61 | volatile int32_t *ptr) |
| 62 | { |
| 63 | *ptr = value; |
| 64 | android_memory_barrier(); |
| 65 | } |
| 66 | |
| 67 | extern inline void android_atomic_release_store(int32_t value, |
| 68 | volatile int32_t *ptr) |
| 69 | { |
| 70 | android_compiler_barrier(); |
| 71 | *ptr = value; |
| 72 | } |
| 73 | |
| 74 | extern inline int android_atomic_cas(int32_t old_value, int32_t new_value, |
| 75 | volatile int32_t *ptr) |
| 76 | { |
| 77 | int32_t prev; |
| 78 | __asm__ __volatile__ ("lock; cmpxchgl %1, %2" |
| 79 | : "=a" (prev) |
| 80 | : "q" (new_value), "m" (*ptr), "0" (old_value) |
| 81 | : "memory"); |
| 82 | return prev != old_value; |
| 83 | } |
| 84 | |
| 85 | extern inline int android_atomic_acquire_cas(int32_t old_value, |
| 86 | int32_t new_value, |
| 87 | volatile int32_t *ptr) |
| 88 | { |
| 89 | /* Loads are not reordered with other loads. */ |
| 90 | return android_atomic_cas(old_value, new_value, ptr); |
| 91 | } |
| 92 | |
| 93 | extern inline int android_atomic_release_cas(int32_t old_value, |
| 94 | int32_t new_value, |
| 95 | volatile int32_t *ptr) |
| 96 | { |
| 97 | /* Stores are not reordered with other stores. */ |
| 98 | return android_atomic_cas(old_value, new_value, ptr); |
| 99 | } |
| 100 | |
| 101 | extern inline int32_t android_atomic_add(int32_t increment, |
| 102 | volatile int32_t *ptr) |
| 103 | { |
| 104 | __asm__ __volatile__ ("lock; xaddl %0, %1" |
| 105 | : "+r" (increment), "+m" (*ptr) |
| 106 | : : "memory"); |
| 107 | /* increment now holds the old value of *ptr */ |
| 108 | return increment; |
| 109 | } |
| 110 | |
| 111 | extern inline int32_t android_atomic_inc(volatile int32_t *addr) |
| 112 | { |
| 113 | return android_atomic_add(1, addr); |
| 114 | } |
| 115 | |
| 116 | extern inline int32_t android_atomic_dec(volatile int32_t *addr) |
| 117 | { |
| 118 | return android_atomic_add(-1, addr); |
| 119 | } |
| 120 | |
| 121 | extern inline int32_t android_atomic_and(int32_t value, |
| 122 | volatile int32_t *ptr) |
| 123 | { |
| 124 | int32_t prev, status; |
| 125 | do { |
| 126 | prev = *ptr; |
| 127 | status = android_atomic_cas(prev, prev & value, ptr); |
| 128 | } while (__builtin_expect(status != 0, 0)); |
| 129 | return prev; |
| 130 | } |
| 131 | |
| 132 | extern inline int32_t android_atomic_or(int32_t value, volatile int32_t *ptr) |
| 133 | { |
| 134 | int32_t prev, status; |
| 135 | do { |
| 136 | prev = *ptr; |
| 137 | status = android_atomic_cas(prev, prev | value, ptr); |
| 138 | } while (__builtin_expect(status != 0, 0)); |
| 139 | return prev; |
| 140 | } |
| 141 | |
| 142 | #endif /* ANDROID_CUTILS_ATOMIC_X86_H */ |