| 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_ARM_H |
| 18 | #define ANDROID_CUTILS_ATOMIC_ARM_H |
| 19 | |
| 20 | #include <stdint.h> |
| 21 | #include <machine/cpu-features.h> |
| 22 | |
| 23 | extern inline void android_compiler_barrier(void) |
| 24 | { |
| 25 | __asm__ __volatile__ ("" : : : "memory"); |
| 26 | } |
| 27 | |
| 28 | #if ANDROID_SMP == 0 |
| 29 | extern inline void android_memory_barrier(void) |
| 30 | { |
| 31 | android_compiler_barrier(); |
| 32 | } |
| 33 | extern inline void android_memory_store_barrier(void) |
| 34 | { |
| 35 | android_compiler_barrier(); |
| 36 | } |
| 37 | #elif defined(__ARM_HAVE_DMB) |
| 38 | extern inline void android_memory_barrier(void) |
| 39 | { |
| 40 | __asm__ __volatile__ ("dmb" : : : "memory"); |
| 41 | } |
| 42 | extern inline void android_memory_store_barrier(void) |
| 43 | { |
| 44 | __asm__ __volatile__ ("dmb st" : : : "memory"); |
| 45 | } |
| 46 | #elif defined(__ARM_HAVE_LDREX_STREX) |
| 47 | extern inline void android_memory_barrier(void) |
| 48 | { |
| 49 | __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 5" : : "r" (0) : "memory"); |
| 50 | } |
| 51 | extern inline void android_memory_store_barrier(void) |
| 52 | { |
| 53 | android_memory_barrier(); |
| 54 | } |
| 55 | #else |
| 56 | extern inline void android_memory_barrier(void) |
| 57 | { |
| 58 | typedef void (kuser_memory_barrier)(void); |
| 59 | (*(kuser_memory_barrier *)0xffff0fa0)(); |
| 60 | } |
| 61 | extern inline void android_memory_store_barrier(void) |
| 62 | { |
| 63 | android_memory_barrier(); |
| 64 | } |
| 65 | #endif |
| 66 | |
| 67 | extern inline int32_t android_atomic_acquire_load(volatile const int32_t *ptr) |
| 68 | { |
| 69 | int32_t value = *ptr; |
| 70 | android_memory_barrier(); |
| 71 | return value; |
| 72 | } |
| 73 | |
| 74 | extern inline int32_t android_atomic_release_load(volatile const int32_t *ptr) |
| 75 | { |
| 76 | android_memory_barrier(); |
| 77 | return *ptr; |
| 78 | } |
| 79 | |
| 80 | extern inline void android_atomic_acquire_store(int32_t value, |
| 81 | volatile int32_t *ptr) |
| 82 | { |
| 83 | *ptr = value; |
| 84 | android_memory_barrier(); |
| 85 | } |
| 86 | |
| 87 | extern inline void android_atomic_release_store(int32_t value, |
| 88 | volatile int32_t *ptr) |
| 89 | { |
| 90 | android_memory_barrier(); |
| 91 | *ptr = value; |
| 92 | } |
| 93 | |
| 94 | #if defined(__thumb__) |
| 95 | extern int android_atomic_cas(int32_t old_value, int32_t new_value, |
| 96 | volatile int32_t *ptr); |
| 97 | #elif defined(__ARM_HAVE_LDREX_STREX) |
| 98 | extern inline int android_atomic_cas(int32_t old_value, int32_t new_value, |
| 99 | volatile int32_t *ptr) |
| 100 | { |
| 101 | int32_t prev, status; |
| 102 | do { |
| 103 | __asm__ __volatile__ ("ldrex %0, [%3]\n" |
| 104 | "mov %1, #0\n" |
| 105 | "teq %0, %4\n" |
| 106 | "strexeq %1, %5, [%3]" |
| 107 | : "=&r" (prev), "=&r" (status), "+m"(*ptr) |
| 108 | : "r" (ptr), "Ir" (old_value), "r" (new_value) |
| 109 | : "cc"); |
| 110 | } while (__builtin_expect(status != 0, 0)); |
| 111 | return prev != old_value; |
| 112 | } |
| 113 | #else |
| 114 | extern inline int android_atomic_cas(int32_t old_value, int32_t new_value, |
| 115 | volatile int32_t *ptr) |
| 116 | { |
| 117 | typedef int (kuser_cmpxchg)(int32_t, int32_t, volatile int32_t *); |
| 118 | int32_t prev, status; |
| 119 | prev = *ptr; |
| 120 | do { |
| 121 | status = (*(kuser_cmpxchg *)0xffff0fc0)(old_value, new_value, ptr); |
| 122 | if (__builtin_expect(status == 0, 1)) |
| 123 | return 0; |
| 124 | prev = *ptr; |
| 125 | } while (prev == old_value); |
| 126 | return 1; |
| 127 | } |
| 128 | #endif |
| 129 | |
| 130 | extern inline int android_atomic_acquire_cas(int32_t old_value, |
| 131 | int32_t new_value, |
| 132 | volatile int32_t *ptr) |
| 133 | { |
| 134 | int status = android_atomic_cas(old_value, new_value, ptr); |
| 135 | android_memory_barrier(); |
| 136 | return status; |
| 137 | } |
| 138 | |
| 139 | extern inline int android_atomic_release_cas(int32_t old_value, |
| 140 | int32_t new_value, |
| 141 | volatile int32_t *ptr) |
| 142 | { |
| 143 | android_memory_barrier(); |
| 144 | return android_atomic_cas(old_value, new_value, ptr); |
| 145 | } |
| 146 | |
| 147 | |
| 148 | #if defined(__thumb__) |
| 149 | extern int32_t android_atomic_add(int32_t increment, |
| 150 | volatile int32_t *ptr); |
| 151 | #elif defined(__ARM_HAVE_LDREX_STREX) |
| 152 | extern inline int32_t android_atomic_add(int32_t increment, |
| 153 | volatile int32_t *ptr) |
| 154 | { |
| 155 | int32_t prev, tmp, status; |
| 156 | android_memory_barrier(); |
| 157 | do { |
| 158 | __asm__ __volatile__ ("ldrex %0, [%4]\n" |
| 159 | "add %1, %0, %5\n" |
| 160 | "strex %2, %1, [%4]" |
| 161 | : "=&r" (prev), "=&r" (tmp), |
| 162 | "=&r" (status), "+m" (*ptr) |
| 163 | : "r" (ptr), "Ir" (increment) |
| 164 | : "cc"); |
| 165 | } while (__builtin_expect(status != 0, 0)); |
| 166 | return prev; |
| 167 | } |
| 168 | #else |
| 169 | extern inline int32_t android_atomic_add(int32_t increment, |
| 170 | volatile int32_t *ptr) |
| 171 | { |
| 172 | int32_t prev, status; |
| 173 | android_memory_barrier(); |
| 174 | do { |
| 175 | prev = *ptr; |
| 176 | status = android_atomic_cas(prev, prev + increment, ptr); |
| 177 | } while (__builtin_expect(status != 0, 0)); |
| 178 | return prev; |
| 179 | } |
| 180 | #endif |
| 181 | |
| 182 | extern inline int32_t android_atomic_inc(volatile int32_t *addr) |
| 183 | { |
| 184 | return android_atomic_add(1, addr); |
| 185 | } |
| 186 | |
| 187 | extern inline int32_t android_atomic_dec(volatile int32_t *addr) |
| 188 | { |
| 189 | return android_atomic_add(-1, addr); |
| 190 | } |
| 191 | |
| 192 | #if defined(__thumb__) |
| 193 | extern int32_t android_atomic_and(int32_t value, volatile int32_t *ptr); |
| 194 | #elif defined(__ARM_HAVE_LDREX_STREX) |
| 195 | extern inline int32_t android_atomic_and(int32_t value, volatile int32_t *ptr) |
| 196 | { |
| 197 | int32_t prev, tmp, status; |
| 198 | android_memory_barrier(); |
| 199 | do { |
| 200 | __asm__ __volatile__ ("ldrex %0, [%4]\n" |
| 201 | "and %1, %0, %5\n" |
| 202 | "strex %2, %1, [%4]" |
| 203 | : "=&r" (prev), "=&r" (tmp), |
| 204 | "=&r" (status), "+m" (*ptr) |
| 205 | : "r" (ptr), "Ir" (value) |
| 206 | : "cc"); |
| 207 | } while (__builtin_expect(status != 0, 0)); |
| 208 | return prev; |
| 209 | } |
| 210 | #else |
| 211 | extern inline int32_t android_atomic_and(int32_t value, volatile int32_t *ptr) |
| 212 | { |
| 213 | int32_t prev, status; |
| 214 | android_memory_barrier(); |
| 215 | do { |
| 216 | prev = *ptr; |
| 217 | status = android_atomic_cas(prev, prev & value, ptr); |
| 218 | } while (__builtin_expect(status != 0, 0)); |
| 219 | return prev; |
| 220 | } |
| 221 | #endif |
| 222 | |
| 223 | #if defined(__thumb__) |
| 224 | extern int32_t android_atomic_or(int32_t value, volatile int32_t *ptr); |
| 225 | #elif defined(__ARM_HAVE_LDREX_STREX) |
| 226 | extern inline int32_t android_atomic_or(int32_t value, volatile int32_t *ptr) |
| 227 | { |
| 228 | int32_t prev, tmp, status; |
| 229 | android_memory_barrier(); |
| 230 | do { |
| 231 | __asm__ __volatile__ ("ldrex %0, [%4]\n" |
| 232 | "orr %1, %0, %5\n" |
| 233 | "strex %2, %1, [%4]" |
| 234 | : "=&r" (prev), "=&r" (tmp), |
| 235 | "=&r" (status), "+m" (*ptr) |
| 236 | : "r" (ptr), "Ir" (value) |
| 237 | : "cc"); |
| 238 | } while (__builtin_expect(status != 0, 0)); |
| 239 | return prev; |
| 240 | } |
| 241 | #else |
| 242 | extern inline int32_t android_atomic_or(int32_t value, volatile int32_t *ptr) |
| 243 | { |
| 244 | int32_t prev, status; |
| 245 | android_memory_barrier(); |
| 246 | do { |
| 247 | prev = *ptr; |
| 248 | status = android_atomic_cas(prev, prev | value, ptr); |
| 249 | } while (__builtin_expect(status != 0, 0)); |
| 250 | return prev; |
| 251 | } |
| 252 | #endif |
| 253 | |
| 254 | #endif /* ANDROID_CUTILS_ATOMIC_ARM_H */ |