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| 1 /* Copyright (c) 2008, Google Inc. |
| 2 * All rights reserved. |
| 3 * |
| 4 * Redistribution and use in source and binary forms, with or without |
| 5 * modification, are permitted provided that the following conditions are |
| 6 * met: |
| 7 * |
| 8 * * Redistributions of source code must retain the above copyright |
| 9 * notice, this list of conditions and the following disclaimer. |
| 10 * * Redistributions in binary form must reproduce the above |
| 11 * copyright notice, this list of conditions and the following disclaimer |
| 12 * in the documentation and/or other materials provided with the |
| 13 * distribution. |
| 14 * * Neither the name of Google Inc. nor the names of its |
| 15 * contributors may be used to endorse or promote products derived from |
| 16 * this software without specific prior written permission. |
| 17 * |
| 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 29 * |
| 30 * --- |
| 31 */ |
| 32 |
| 33 // Implementation of atomic operations for ppc-linux. This file should not |
| 34 // be included directly. Clients should instead include |
| 35 // "base/atomicops.h". |
| 36 |
| 37 #ifndef BASE_ATOMICOPS_INTERNALS_LINUXPPC_H_ |
| 38 #define BASE_ATOMICOPS_INTERNALS_LINUXPPC_H_ |
| 39 |
| 40 typedef int32_t Atomic32; |
| 41 |
| 42 #ifdef __PPC64__ |
| 43 #define BASE_HAS_ATOMIC64 1 |
| 44 #endif |
| 45 |
| 46 namespace base { |
| 47 namespace subtle { |
| 48 |
| 49 static inline void _sync(void) { |
| 50 __asm__ __volatile__("sync": : : "memory"); |
| 51 } |
| 52 |
| 53 static inline void _lwsync(void) { |
| 54 // gcc defines __NO_LWSYNC__ when appropriate; see |
| 55 // http://gcc.gnu.org/ml/gcc-patches/2006-11/msg01238.html |
| 56 #ifdef __NO_LWSYNC__ |
| 57 __asm__ __volatile__("msync": : : "memory"); |
| 58 #else |
| 59 __asm__ __volatile__("lwsync": : : "memory"); |
| 60 #endif |
| 61 } |
| 62 |
| 63 static inline void _isync(void) { |
| 64 __asm__ __volatile__("isync": : : "memory"); |
| 65 } |
| 66 |
| 67 static inline Atomic32 OSAtomicAdd32(Atomic32 amount, Atomic32 *value) { |
| 68 Atomic32 t; |
| 69 __asm__ __volatile__( |
| 70 "1: lwarx %0,0,%3\n\ |
| 71 add %0,%2,%0\n\ |
| 72 stwcx. %0,0,%3 \n\ |
| 73 bne- 1b" |
| 74 : "=&r" (t), "+m" (*value) |
| 75 : "r" (amount), "r" (value) |
| 76 : "cc"); |
| 77 return t; |
| 78 } |
| 79 |
| 80 static inline Atomic32 OSAtomicAdd32Barrier(Atomic32 amount, Atomic32 *value) { |
| 81 Atomic32 t; |
| 82 _lwsync(); |
| 83 t = OSAtomicAdd32(amount, value); |
| 84 // This is based on the code snippet in the architecture manual (Vol |
| 85 // 2, Appendix B). It's a little tricky: correctness depends on the |
| 86 // fact that the code right before this (in OSAtomicAdd32) has a |
| 87 // conditional branch with a data dependency on the update. |
| 88 // Otherwise, we'd have to use sync. |
| 89 _isync(); |
| 90 return t; |
| 91 } |
| 92 |
| 93 static inline bool OSAtomicCompareAndSwap32(Atomic32 old_value, |
| 94 Atomic32 new_value, |
| 95 Atomic32 *value) { |
| 96 Atomic32 prev; |
| 97 __asm__ __volatile__( |
| 98 "1: lwarx %0,0,%2\n\ |
| 99 cmpw 0,%0,%3\n\ |
| 100 bne- 2f\n\ |
| 101 stwcx. %4,0,%2\n\ |
| 102 bne- 1b\n\ |
| 103 2:" |
| 104 : "=&r" (prev), "+m" (*value) |
| 105 : "r" (value), "r" (old_value), "r" (new_value) |
| 106 : "cc"); |
| 107 return prev == old_value; |
| 108 } |
| 109 |
| 110 static inline Atomic32 OSAtomicCompareAndSwap32Acquire(Atomic32 old_value, |
| 111 Atomic32 new_value, |
| 112 Atomic32 *value) { |
| 113 Atomic32 t; |
| 114 t = OSAtomicCompareAndSwap32(old_value, new_value, value); |
| 115 // This is based on the code snippet in the architecture manual (Vol |
| 116 // 2, Appendix B). It's a little tricky: correctness depends on the |
| 117 // fact that the code right before this (in |
| 118 // OSAtomicCompareAndSwap32) has a conditional branch with a data |
| 119 // dependency on the update. Otherwise, we'd have to use sync. |
| 120 _isync(); |
| 121 return t; |
| 122 } |
| 123 |
| 124 static inline Atomic32 OSAtomicCompareAndSwap32Release(Atomic32 old_value, |
| 125 Atomic32 new_value, |
| 126 Atomic32 *value) { |
| 127 _lwsync(); |
| 128 return OSAtomicCompareAndSwap32(old_value, new_value, value); |
| 129 } |
| 130 |
| 131 typedef int64_t Atomic64; |
| 132 |
| 133 inline void MemoryBarrier() { |
| 134 // This can't be _lwsync(); we need to order the immediately |
| 135 // preceding stores against any load that may follow, but lwsync |
| 136 // doesn't guarantee that. |
| 137 _sync(); |
| 138 } |
| 139 |
| 140 // 32-bit Versions. |
| 141 |
| 142 inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32 *ptr, |
| 143 Atomic32 old_value, |
| 144 Atomic32 new_value) { |
| 145 Atomic32 prev_value; |
| 146 do { |
| 147 if (OSAtomicCompareAndSwap32(old_value, new_value, |
| 148 const_cast<Atomic32*>(ptr))) { |
| 149 return old_value; |
| 150 } |
| 151 prev_value = *ptr; |
| 152 } while (prev_value == old_value); |
| 153 return prev_value; |
| 154 } |
| 155 |
| 156 inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32 *ptr, |
| 157 Atomic32 new_value) { |
| 158 Atomic32 old_value; |
| 159 do { |
| 160 old_value = *ptr; |
| 161 } while (!OSAtomicCompareAndSwap32(old_value, new_value, |
| 162 const_cast<Atomic32*>(ptr))); |
| 163 return old_value; |
| 164 } |
| 165 |
| 166 inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32 *ptr, |
| 167 Atomic32 increment) { |
| 168 return OSAtomicAdd32(increment, const_cast<Atomic32*>(ptr)); |
| 169 } |
| 170 |
| 171 inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32 *ptr, |
| 172 Atomic32 increment) { |
| 173 return OSAtomicAdd32Barrier(increment, const_cast<Atomic32*>(ptr)); |
| 174 } |
| 175 |
| 176 inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32 *ptr, |
| 177 Atomic32 old_value, |
| 178 Atomic32 new_value) { |
| 179 Atomic32 prev_value; |
| 180 do { |
| 181 if (OSAtomicCompareAndSwap32Acquire(old_value, new_value, |
| 182 const_cast<Atomic32*>(ptr))) { |
| 183 return old_value; |
| 184 } |
| 185 prev_value = *ptr; |
| 186 } while (prev_value == old_value); |
| 187 return prev_value; |
| 188 } |
| 189 |
| 190 inline Atomic32 Release_CompareAndSwap(volatile Atomic32 *ptr, |
| 191 Atomic32 old_value, |
| 192 Atomic32 new_value) { |
| 193 Atomic32 prev_value; |
| 194 do { |
| 195 if (OSAtomicCompareAndSwap32Release(old_value, new_value, |
| 196 const_cast<Atomic32*>(ptr))) { |
| 197 return old_value; |
| 198 } |
| 199 prev_value = *ptr; |
| 200 } while (prev_value == old_value); |
| 201 return prev_value; |
| 202 } |
| 203 |
| 204 #ifdef __PPC64__ |
| 205 |
| 206 // 64-bit Versions. |
| 207 |
| 208 static inline Atomic64 OSAtomicAdd64(Atomic64 amount, Atomic64 *value) { |
| 209 Atomic64 t; |
| 210 __asm__ __volatile__( |
| 211 "1: ldarx %0,0,%3\n\ |
| 212 add %0,%2,%0\n\ |
| 213 stdcx. %0,0,%3 \n\ |
| 214 bne- 1b" |
| 215 : "=&r" (t), "+m" (*value) |
| 216 : "r" (amount), "r" (value) |
| 217 : "cc"); |
| 218 return t; |
| 219 } |
| 220 |
| 221 static inline Atomic64 OSAtomicAdd64Barrier(Atomic64 amount, Atomic64 *value) { |
| 222 Atomic64 t; |
| 223 _lwsync(); |
| 224 t = OSAtomicAdd64(amount, value); |
| 225 // This is based on the code snippet in the architecture manual (Vol |
| 226 // 2, Appendix B). It's a little tricky: correctness depends on the |
| 227 // fact that the code right before this (in OSAtomicAdd64) has a |
| 228 // conditional branch with a data dependency on the update. |
| 229 // Otherwise, we'd have to use sync. |
| 230 _isync(); |
| 231 return t; |
| 232 } |
| 233 |
| 234 static inline bool OSAtomicCompareAndSwap64(Atomic64 old_value, |
| 235 Atomic64 new_value, |
| 236 Atomic64 *value) { |
| 237 Atomic64 prev; |
| 238 __asm__ __volatile__( |
| 239 "1: ldarx %0,0,%2\n\ |
| 240 cmpw 0,%0,%3\n\ |
| 241 bne- 2f\n\ |
| 242 stdcx. %4,0,%2\n\ |
| 243 bne- 1b\n\ |
| 244 2:" |
| 245 : "=&r" (prev), "+m" (*value) |
| 246 : "r" (value), "r" (old_value), "r" (new_value) |
| 247 : "cc"); |
| 248 return prev == old_value; |
| 249 } |
| 250 |
| 251 static inline Atomic64 OSAtomicCompareAndSwap64Acquire(Atomic64 old_value, |
| 252 Atomic64 new_value, |
| 253 Atomic64 *value) { |
| 254 Atomic64 t; |
| 255 t = OSAtomicCompareAndSwap64(old_value, new_value, value); |
| 256 // This is based on the code snippet in the architecture manual (Vol |
| 257 // 2, Appendix B). It's a little tricky: correctness depends on the |
| 258 // fact that the code right before this (in |
| 259 // OSAtomicCompareAndSwap64) has a conditional branch with a data |
| 260 // dependency on the update. Otherwise, we'd have to use sync. |
| 261 _isync(); |
| 262 return t; |
| 263 } |
| 264 |
| 265 static inline Atomic64 OSAtomicCompareAndSwap64Release(Atomic64 old_value, |
| 266 Atomic64 new_value, |
| 267 Atomic64 *value) { |
| 268 _lwsync(); |
| 269 return OSAtomicCompareAndSwap64(old_value, new_value, value); |
| 270 } |
| 271 |
| 272 |
| 273 inline Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64 *ptr, |
| 274 Atomic64 old_value, |
| 275 Atomic64 new_value) { |
| 276 Atomic64 prev_value; |
| 277 do { |
| 278 if (OSAtomicCompareAndSwap64(old_value, new_value, |
| 279 const_cast<Atomic64*>(ptr))) { |
| 280 return old_value; |
| 281 } |
| 282 prev_value = *ptr; |
| 283 } while (prev_value == old_value); |
| 284 return prev_value; |
| 285 } |
| 286 |
| 287 inline Atomic64 NoBarrier_AtomicExchange(volatile Atomic64 *ptr, |
| 288 Atomic64 new_value) { |
| 289 Atomic64 old_value; |
| 290 do { |
| 291 old_value = *ptr; |
| 292 } while (!OSAtomicCompareAndSwap64(old_value, new_value, |
| 293 const_cast<Atomic64*>(ptr))); |
| 294 return old_value; |
| 295 } |
| 296 |
| 297 inline Atomic64 NoBarrier_AtomicIncrement(volatile Atomic64 *ptr, |
| 298 Atomic64 increment) { |
| 299 return OSAtomicAdd64(increment, const_cast<Atomic64*>(ptr)); |
| 300 } |
| 301 |
| 302 inline Atomic64 Barrier_AtomicIncrement(volatile Atomic64 *ptr, |
| 303 Atomic64 increment) { |
| 304 return OSAtomicAdd64Barrier(increment, const_cast<Atomic64*>(ptr)); |
| 305 } |
| 306 |
| 307 inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64 *ptr, |
| 308 Atomic64 old_value, |
| 309 Atomic64 new_value) { |
| 310 Atomic64 prev_value; |
| 311 do { |
| 312 if (OSAtomicCompareAndSwap64Acquire(old_value, new_value, |
| 313 const_cast<Atomic64*>(ptr))) { |
| 314 return old_value; |
| 315 } |
| 316 prev_value = *ptr; |
| 317 } while (prev_value == old_value); |
| 318 return prev_value; |
| 319 } |
| 320 |
| 321 inline Atomic64 Release_CompareAndSwap(volatile Atomic64 *ptr, |
| 322 Atomic64 old_value, |
| 323 Atomic64 new_value) { |
| 324 Atomic64 prev_value; |
| 325 do { |
| 326 if (OSAtomicCompareAndSwap64Release(old_value, new_value, |
| 327 const_cast<Atomic64*>(ptr))) { |
| 328 return old_value; |
| 329 } |
| 330 prev_value = *ptr; |
| 331 } while (prev_value == old_value); |
| 332 return prev_value; |
| 333 } |
| 334 |
| 335 #endif |
| 336 |
| 337 inline void NoBarrier_Store(volatile Atomic32 *ptr, Atomic32 value) { |
| 338 *ptr = value; |
| 339 } |
| 340 |
| 341 inline void Acquire_Store(volatile Atomic32 *ptr, Atomic32 value) { |
| 342 *ptr = value; |
| 343 // This can't be _lwsync(); we need to order the immediately |
| 344 // preceding stores against any load that may follow, but lwsync |
| 345 // doesn't guarantee that. |
| 346 _sync(); |
| 347 } |
| 348 |
| 349 inline void Release_Store(volatile Atomic32 *ptr, Atomic32 value) { |
| 350 _lwsync(); |
| 351 *ptr = value; |
| 352 } |
| 353 |
| 354 inline Atomic32 NoBarrier_Load(volatile const Atomic32 *ptr) { |
| 355 return *ptr; |
| 356 } |
| 357 |
| 358 inline Atomic32 Acquire_Load(volatile const Atomic32 *ptr) { |
| 359 Atomic32 value = *ptr; |
| 360 _lwsync(); |
| 361 return value; |
| 362 } |
| 363 |
| 364 inline Atomic32 Release_Load(volatile const Atomic32 *ptr) { |
| 365 // This can't be _lwsync(); we need to order the immediately |
| 366 // preceding stores against any load that may follow, but lwsync |
| 367 // doesn't guarantee that. |
| 368 _sync(); |
| 369 return *ptr; |
| 370 } |
| 371 |
| 372 #ifdef __PPC64__ |
| 373 |
| 374 // 64-bit Versions. |
| 375 |
| 376 inline void NoBarrier_Store(volatile Atomic64 *ptr, Atomic64 value) { |
| 377 *ptr = value; |
| 378 } |
| 379 |
| 380 inline void Acquire_Store(volatile Atomic64 *ptr, Atomic64 value) { |
| 381 *ptr = value; |
| 382 // This can't be _lwsync(); we need to order the immediately |
| 383 // preceding stores against any load that may follow, but lwsync |
| 384 // doesn't guarantee that. |
| 385 _sync(); |
| 386 } |
| 387 |
| 388 inline void Release_Store(volatile Atomic64 *ptr, Atomic64 value) { |
| 389 _lwsync(); |
| 390 *ptr = value; |
| 391 } |
| 392 |
| 393 inline Atomic64 NoBarrier_Load(volatile const Atomic64 *ptr) { |
| 394 return *ptr; |
| 395 } |
| 396 |
| 397 inline Atomic64 Acquire_Load(volatile const Atomic64 *ptr) { |
| 398 Atomic64 value = *ptr; |
| 399 _lwsync(); |
| 400 return value; |
| 401 } |
| 402 |
| 403 inline Atomic64 Release_Load(volatile const Atomic64 *ptr) { |
| 404 // This can't be _lwsync(); we need to order the immediately |
| 405 // preceding stores against any load that may follow, but lwsync |
| 406 // doesn't guarantee that. |
| 407 _sync(); |
| 408 return *ptr; |
| 409 } |
| 410 |
| 411 #endif |
| 412 |
| 413 } // namespace base::subtle |
| 414 } // namespace base |
| 415 |
| 416 #endif // BASE_ATOMICOPS_INTERNALS_LINUXPPC_H_ |
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