Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 | /* atomic operations */ /* * Copyright (c) 1997-2015, Wind River Systems, Inc. * * SPDX-License-Identifier: Apache-2.0 */ #ifndef ZEPHYR_INCLUDE_ATOMIC_H_ #define ZEPHYR_INCLUDE_ATOMIC_H_ #include <stdbool.h> #include <toolchain.h> #include <zephyr/types.h> #ifdef __cplusplus extern "C" { #endif typedef int atomic_t; typedef atomic_t atomic_val_t; /** * @defgroup atomic_apis Atomic Services APIs * @ingroup kernel_apis * @{ */ /** * @brief Atomic compare-and-set. * * This routine performs an atomic compare-and-set on @a target. If the current * value of @a target equals @a old_value, @a target is set to @a new_value. * If the current value of @a target does not equal @a old_value, @a target * is left unchanged. * * @param target Address of atomic variable. * @param old_value Original value to compare against. * @param new_value New value to store. * @return true if @a new_value is written, false otherwise. */ #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN static inline bool atomic_cas(atomic_t *target, atomic_val_t old_value, atomic_val_t new_value) { return __atomic_compare_exchange_n(target, &old_value, new_value, 0, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST); } #elif defined(CONFIG_ATOMIC_OPERATIONS_C) __syscall int atomic_cas(atomic_t *target, atomic_val_t old_value, atomic_val_t new_value); #else extern int atomic_cas(atomic_t *target, atomic_val_t old_value, atomic_val_t new_value); #endif /** * * @brief Atomic addition. * * This routine performs an atomic addition on @a target. * * @param target Address of atomic variable. * @param value Value to add. * * @return Previous value of @a target. */ #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN static inline atomic_val_t atomic_add(atomic_t *target, atomic_val_t value) { return __atomic_fetch_add(target, value, __ATOMIC_SEQ_CST); } #elif defined(CONFIG_ATOMIC_OPERATIONS_C) __syscall atomic_val_t atomic_add(atomic_t *target, atomic_val_t value); #else extern atomic_val_t atomic_add(atomic_t *target, atomic_val_t value); #endif /** * * @brief Atomic subtraction. * * This routine performs an atomic subtraction on @a target. * * @param target Address of atomic variable. * @param value Value to subtract. * * @return Previous value of @a target. */ #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN static inline atomic_val_t atomic_sub(atomic_t *target, atomic_val_t value) { return __atomic_fetch_sub(target, value, __ATOMIC_SEQ_CST); } #elif defined(CONFIG_ATOMIC_OPERATIONS_C) __syscall atomic_val_t atomic_sub(atomic_t *target, atomic_val_t value); #else extern atomic_val_t atomic_sub(atomic_t *target, atomic_val_t value); #endif /** * * @brief Atomic increment. * * This routine performs an atomic increment by 1 on @a target. * * @param target Address of atomic variable. * * @return Previous value of @a target. */ #if defined(CONFIG_ATOMIC_OPERATIONS_BUILTIN) || defined (CONFIG_ATOMIC_OPERATIONS_C) static inline atomic_val_t atomic_inc(atomic_t *target) { return atomic_add(target, 1); } #else extern atomic_val_t atomic_inc(atomic_t *target); #endif /** * * @brief Atomic decrement. * * This routine performs an atomic decrement by 1 on @a target. * * @param target Address of atomic variable. * * @return Previous value of @a target. */ #if defined(CONFIG_ATOMIC_OPERATIONS_BUILTIN) || defined (CONFIG_ATOMIC_OPERATIONS_C) static inline atomic_val_t atomic_dec(atomic_t *target) { return atomic_sub(target, 1); } #else extern atomic_val_t atomic_dec(atomic_t *target); #endif /** * * @brief Atomic get. * * This routine performs an atomic read on @a target. * * @param target Address of atomic variable. * * @return Value of @a target. */ #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN static inline atomic_val_t atomic_get(const atomic_t *target) { return __atomic_load_n(target, __ATOMIC_SEQ_CST); } #else extern atomic_val_t atomic_get(const atomic_t *target); #endif /** * * @brief Atomic get-and-set. * * This routine atomically sets @a target to @a value and returns * the previous value of @a target. * * @param target Address of atomic variable. * @param value Value to write to @a target. * * @return Previous value of @a target. */ #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN static inline atomic_val_t atomic_set(atomic_t *target, atomic_val_t value) { /* This builtin, as described by Intel, is not a traditional * test-and-set operation, but rather an atomic exchange operation. It * writes value into *ptr, and returns the previous contents of *ptr. */ return __atomic_exchange_n(target, value, __ATOMIC_SEQ_CST); } #elif defined(CONFIG_ATOMIC_OPERATIONS_C) __syscall atomic_val_t atomic_set(atomic_t *target, atomic_val_t value); #else extern atomic_val_t atomic_set(atomic_t *target, atomic_val_t value); #endif /** * * @brief Atomic clear. * * This routine atomically sets @a target to zero and returns its previous * value. (Hence, it is equivalent to atomic_set(target, 0).) * * @param target Address of atomic variable. * * @return Previous value of @a target. */ #if defined(CONFIG_ATOMIC_OPERATIONS_BUILTIN) || defined (CONFIG_ATOMIC_OPERATIONS_C) static inline atomic_val_t atomic_clear(atomic_t *target) { return atomic_set(target, 0); } #else extern atomic_val_t atomic_clear(atomic_t *target); #endif /** * * @brief Atomic bitwise inclusive OR. * * This routine atomically sets @a target to the bitwise inclusive OR of * @a target and @a value. * * @param target Address of atomic variable. * @param value Value to OR. * * @return Previous value of @a target. */ #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN static inline atomic_val_t atomic_or(atomic_t *target, atomic_val_t value) { return __atomic_fetch_or(target, value, __ATOMIC_SEQ_CST); } #elif defined(CONFIG_ATOMIC_OPERATIONS_C) __syscall atomic_val_t atomic_or(atomic_t *target, atomic_val_t value); #else extern atomic_val_t atomic_or(atomic_t *target, atomic_val_t value); #endif /** * * @brief Atomic bitwise exclusive OR (XOR). * * This routine atomically sets @a target to the bitwise exclusive OR (XOR) of * @a target and @a value. * * @param target Address of atomic variable. * @param value Value to XOR * * @return Previous value of @a target. */ #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN static inline atomic_val_t atomic_xor(atomic_t *target, atomic_val_t value) { return __atomic_fetch_xor(target, value, __ATOMIC_SEQ_CST); } #elif defined(CONFIG_ATOMIC_OPERATIONS_C) __syscall atomic_val_t atomic_xor(atomic_t *target, atomic_val_t value); #else extern atomic_val_t atomic_xor(atomic_t *target, atomic_val_t value); #endif /** * * @brief Atomic bitwise AND. * * This routine atomically sets @a target to the bitwise AND of @a target * and @a value. * * @param target Address of atomic variable. * @param value Value to AND. * * @return Previous value of @a target. */ #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN static inline atomic_val_t atomic_and(atomic_t *target, atomic_val_t value) { return __atomic_fetch_and(target, value, __ATOMIC_SEQ_CST); } #elif defined(CONFIG_ATOMIC_OPERATIONS_C) __syscall atomic_val_t atomic_and(atomic_t *target, atomic_val_t value); #else extern atomic_val_t atomic_and(atomic_t *target, atomic_val_t value); #endif /** * * @brief Atomic bitwise NAND. * * This routine atomically sets @a target to the bitwise NAND of @a target * and @a value. (This operation is equivalent to target = ~(target & value).) * * @param target Address of atomic variable. * @param value Value to NAND. * * @return Previous value of @a target. */ #ifdef CONFIG_ATOMIC_OPERATIONS_BUILTIN static inline atomic_val_t atomic_nand(atomic_t *target, atomic_val_t value) { return __atomic_fetch_nand(target, value, __ATOMIC_SEQ_CST); } #elif defined(CONFIG_ATOMIC_OPERATIONS_C) __syscall atomic_val_t atomic_nand(atomic_t *target, atomic_val_t value); #else extern atomic_val_t atomic_nand(atomic_t *target, atomic_val_t value); #endif /** * @brief Initialize an atomic variable. * * This macro can be used to initialize an atomic variable. For example, * @code atomic_t my_var = ATOMIC_INIT(75); @endcode * * @param i Value to assign to atomic variable. */ #define ATOMIC_INIT(i) (i) /** * @cond INTERNAL_HIDDEN */ #define ATOMIC_BITS (sizeof(atomic_val_t) * 8) #define ATOMIC_MASK(bit) (1 << ((u32_t)(bit) & (ATOMIC_BITS - 1))) #define ATOMIC_ELEM(addr, bit) ((addr) + ((bit) / ATOMIC_BITS)) /** * INTERNAL_HIDDEN @endcond */ /** * @brief Define an array of atomic variables. * * This macro defines an array of atomic variables containing at least * @a num_bits bits. * * @note * If used from file scope, the bits of the array are initialized to zero; * if used from within a function, the bits are left uninitialized. * * @param name Name of array of atomic variables. * @param num_bits Number of bits needed. */ #define ATOMIC_DEFINE(name, num_bits) \ atomic_t name[1 + ((num_bits) - 1) / ATOMIC_BITS] /** * @brief Atomically test a bit. * * This routine tests whether bit number @a bit of @a target is set or not. * The target may be a single atomic variable or an array of them. * * @param target Address of atomic variable or array. * @param bit Bit number (starting from 0). * * @return true if the bit was set, false if it wasn't. */ static inline bool atomic_test_bit(const atomic_t *target, int bit) { atomic_val_t val = atomic_get(ATOMIC_ELEM(target, bit)); return (1 & (val >> (bit & (ATOMIC_BITS - 1)))) != 0; } /** * @brief Atomically test and clear a bit. * * Atomically clear bit number @a bit of @a target and return its old value. * The target may be a single atomic variable or an array of them. * * @param target Address of atomic variable or array. * @param bit Bit number (starting from 0). * * @return true if the bit was set, false if it wasn't. */ static inline bool atomic_test_and_clear_bit(atomic_t *target, int bit) { atomic_val_t mask = ATOMIC_MASK(bit); atomic_val_t old; old = atomic_and(ATOMIC_ELEM(target, bit), ~mask); return (old & mask) != 0; } /** * @brief Atomically set a bit. * * Atomically set bit number @a bit of @a target and return its old value. * The target may be a single atomic variable or an array of them. * * @param target Address of atomic variable or array. * @param bit Bit number (starting from 0). * * @return true if the bit was set, false if it wasn't. */ static inline bool atomic_test_and_set_bit(atomic_t *target, int bit) { atomic_val_t mask = ATOMIC_MASK(bit); atomic_val_t old; old = atomic_or(ATOMIC_ELEM(target, bit), mask); return (old & mask) != 0; } /** * @brief Atomically clear a bit. * * Atomically clear bit number @a bit of @a target. * The target may be a single atomic variable or an array of them. * * @param target Address of atomic variable or array. * @param bit Bit number (starting from 0). * * @return N/A */ static inline void atomic_clear_bit(atomic_t *target, int bit) { atomic_val_t mask = ATOMIC_MASK(bit); (void)atomic_and(ATOMIC_ELEM(target, bit), ~mask); } /** * @brief Atomically set a bit. * * Atomically set bit number @a bit of @a target. * The target may be a single atomic variable or an array of them. * * @param target Address of atomic variable or array. * @param bit Bit number (starting from 0). * * @return N/A */ static inline void atomic_set_bit(atomic_t *target, int bit) { atomic_val_t mask = ATOMIC_MASK(bit); (void)atomic_or(ATOMIC_ELEM(target, bit), mask); } /** * @brief Atomically set a bit to a given value. * * Atomically set bit number @a bit of @a target to value @a val. * The target may be a single atomic variable or an array of them. * * @param target Address of atomic variable or array. * @param bit Bit number (starting from 0). * @param val true for 1, false for 0. * * @return N/A */ static inline void atomic_set_bit_to(atomic_t *target, int bit, bool val) { atomic_val_t mask = ATOMIC_MASK(bit); if (val) { (void)atomic_or(ATOMIC_ELEM(target, bit), mask); } else { (void)atomic_and(ATOMIC_ELEM(target, bit), ~mask); } } #ifdef CONFIG_ATOMIC_OPERATIONS_C #include <syscalls/atomic.h> #endif /** * @} */ #ifdef __cplusplus } #endif #endif /* ZEPHYR_INCLUDE_ATOMIC_H_ */ |