| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | #ifndef _LINUX_WAIT_H |
| 3 | #define _LINUX_WAIT_H |
| 4 | /* |
| 5 | * Linux wait queue related types and methods |
| 6 | */ |
| 7 | #include <linux/list.h> |
| 8 | #include <linux/stddef.h> |
| 9 | #include <linux/spinlock.h> |
| 10 | |
| 11 | #include <asm/current.h> |
| 12 | #include <uapi/linux/wait.h> |
| 13 | |
| 14 | typedef struct wait_queue_entry wait_queue_entry_t; |
| 15 | |
| 16 | typedef int (*wait_queue_func_t)(struct wait_queue_entry *wq_entry, unsigned mode, int flags, void *key); |
| 17 | int default_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int flags, void *key); |
| 18 | |
| 19 | /* wait_queue_entry::flags */ |
| 20 | #define WQ_FLAG_EXCLUSIVE 0x01 |
| 21 | #define WQ_FLAG_WOKEN 0x02 |
| 22 | #define WQ_FLAG_BOOKMARK 0x04 |
| 23 | #define WQ_FLAG_CUSTOM 0x08 |
| 24 | #define WQ_FLAG_DONE 0x10 |
| 25 | #define WQ_FLAG_PRIORITY 0x20 |
| 26 | |
| 27 | /* |
| 28 | * A single wait-queue entry structure: |
| 29 | */ |
| 30 | struct wait_queue_entry { |
| 31 | unsigned int flags; |
| 32 | void *private; |
| 33 | wait_queue_func_t func; |
| 34 | struct list_head entry; |
| 35 | }; |
| 36 | |
| 37 | struct wait_queue_head { |
| 38 | spinlock_t lock; |
| 39 | struct list_head head; |
| 40 | }; |
| 41 | typedef struct wait_queue_head wait_queue_head_t; |
| 42 | |
| 43 | struct task_struct; |
| 44 | |
| 45 | /* |
| 46 | * Macros for declaration and initialisaton of the datatypes |
| 47 | */ |
| 48 | |
| 49 | #define __WAITQUEUE_INITIALIZER(name, tsk) { \ |
| 50 | .private = tsk, \ |
| 51 | .func = default_wake_function, \ |
| 52 | .entry = { NULL, NULL } } |
| 53 | |
| 54 | #define DECLARE_WAITQUEUE(name, tsk) \ |
| 55 | struct wait_queue_entry name = __WAITQUEUE_INITIALIZER(name, tsk) |
| 56 | |
| 57 | #define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \ |
| 58 | .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ |
| 59 | .head = LIST_HEAD_INIT(name.head) } |
| 60 | |
| 61 | #define DECLARE_WAIT_QUEUE_HEAD(name) \ |
| 62 | struct wait_queue_head name = __WAIT_QUEUE_HEAD_INITIALIZER(name) |
| 63 | |
| 64 | extern void __init_waitqueue_head(struct wait_queue_head *wq_head, const char *name, struct lock_class_key *); |
| 65 | |
| 66 | #define init_waitqueue_head(wq_head) \ |
| 67 | do { \ |
| 68 | static struct lock_class_key __key; \ |
| 69 | \ |
| 70 | __init_waitqueue_head((wq_head), #wq_head, &__key); \ |
| 71 | } while (0) |
| 72 | |
| 73 | #ifdef CONFIG_LOCKDEP |
| 74 | # define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \ |
| 75 | ({ init_waitqueue_head(&name); name; }) |
| 76 | # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \ |
| 77 | struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) |
| 78 | #else |
| 79 | # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name) |
| 80 | #endif |
| 81 | |
| 82 | static inline void init_waitqueue_entry(struct wait_queue_entry *wq_entry, struct task_struct *p) |
| 83 | { |
| 84 | wq_entry->flags = 0; |
| 85 | wq_entry->private = p; |
| 86 | wq_entry->func = default_wake_function; |
| 87 | } |
| 88 | |
| 89 | static inline void |
| 90 | init_waitqueue_func_entry(struct wait_queue_entry *wq_entry, wait_queue_func_t func) |
| 91 | { |
| 92 | wq_entry->flags = 0; |
| 93 | wq_entry->private = NULL; |
| 94 | wq_entry->func = func; |
| 95 | } |
| 96 | |
| 97 | /** |
| 98 | * waitqueue_active -- locklessly test for waiters on the queue |
| 99 | * @wq_head: the waitqueue to test for waiters |
| 100 | * |
| 101 | * returns true if the wait list is not empty |
| 102 | * |
| 103 | * NOTE: this function is lockless and requires care, incorrect usage _will_ |
| 104 | * lead to sporadic and non-obvious failure. |
| 105 | * |
| 106 | * Use either while holding wait_queue_head::lock or when used for wakeups |
| 107 | * with an extra smp_mb() like:: |
| 108 | * |
| 109 | * CPU0 - waker CPU1 - waiter |
| 110 | * |
| 111 | * for (;;) { |
| 112 | * @cond = true; prepare_to_wait(&wq_head, &wait, state); |
| 113 | * smp_mb(); // smp_mb() from set_current_state() |
| 114 | * if (waitqueue_active(wq_head)) if (@cond) |
| 115 | * wake_up(wq_head); break; |
| 116 | * schedule(); |
| 117 | * } |
| 118 | * finish_wait(&wq_head, &wait); |
| 119 | * |
| 120 | * Because without the explicit smp_mb() it's possible for the |
| 121 | * waitqueue_active() load to get hoisted over the @cond store such that we'll |
| 122 | * observe an empty wait list while the waiter might not observe @cond. |
| 123 | * |
| 124 | * Also note that this 'optimization' trades a spin_lock() for an smp_mb(), |
| 125 | * which (when the lock is uncontended) are of roughly equal cost. |
| 126 | */ |
| 127 | static inline int waitqueue_active(struct wait_queue_head *wq_head) |
| 128 | { |
| 129 | return !list_empty(&wq_head->head); |
| 130 | } |
| 131 | |
| 132 | /** |
| 133 | * wq_has_single_sleeper - check if there is only one sleeper |
| 134 | * @wq_head: wait queue head |
| 135 | * |
| 136 | * Returns true of wq_head has only one sleeper on the list. |
| 137 | * |
| 138 | * Please refer to the comment for waitqueue_active. |
| 139 | */ |
| 140 | static inline bool wq_has_single_sleeper(struct wait_queue_head *wq_head) |
| 141 | { |
| 142 | return list_is_singular(&wq_head->head); |
| 143 | } |
| 144 | |
| 145 | /** |
| 146 | * wq_has_sleeper - check if there are any waiting processes |
| 147 | * @wq_head: wait queue head |
| 148 | * |
| 149 | * Returns true if wq_head has waiting processes |
| 150 | * |
| 151 | * Please refer to the comment for waitqueue_active. |
| 152 | */ |
| 153 | static inline bool wq_has_sleeper(struct wait_queue_head *wq_head) |
| 154 | { |
| 155 | /* |
| 156 | * We need to be sure we are in sync with the |
| 157 | * add_wait_queue modifications to the wait queue. |
| 158 | * |
| 159 | * This memory barrier should be paired with one on the |
| 160 | * waiting side. |
| 161 | */ |
| 162 | smp_mb(); |
| 163 | return waitqueue_active(wq_head); |
| 164 | } |
| 165 | |
| 166 | extern void add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); |
| 167 | extern void add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); |
| 168 | extern void add_wait_queue_priority(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); |
| 169 | extern void remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); |
| 170 | |
| 171 | static inline void __add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) |
| 172 | { |
| 173 | struct list_head *head = &wq_head->head; |
| 174 | struct wait_queue_entry *wq; |
| 175 | |
| 176 | list_for_each_entry(wq, &wq_head->head, entry) { |
| 177 | if (!(wq->flags & WQ_FLAG_PRIORITY)) |
| 178 | break; |
| 179 | head = &wq->entry; |
| 180 | } |
| 181 | list_add(&wq_entry->entry, head); |
| 182 | } |
| 183 | |
| 184 | /* |
| 185 | * Used for wake-one threads: |
| 186 | */ |
| 187 | static inline void |
| 188 | __add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) |
| 189 | { |
| 190 | wq_entry->flags |= WQ_FLAG_EXCLUSIVE; |
| 191 | __add_wait_queue(wq_head, wq_entry); |
| 192 | } |
| 193 | |
| 194 | static inline void __add_wait_queue_entry_tail(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) |
| 195 | { |
| 196 | list_add_tail(&wq_entry->entry, &wq_head->head); |
| 197 | } |
| 198 | |
| 199 | static inline void |
| 200 | __add_wait_queue_entry_tail_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) |
| 201 | { |
| 202 | wq_entry->flags |= WQ_FLAG_EXCLUSIVE; |
| 203 | __add_wait_queue_entry_tail(wq_head, wq_entry); |
| 204 | } |
| 205 | |
| 206 | static inline void |
| 207 | __remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) |
| 208 | { |
| 209 | list_del(&wq_entry->entry); |
| 210 | } |
| 211 | |
| 212 | int __wake_up(struct wait_queue_head *wq_head, unsigned int mode, int nr, void *key); |
| 213 | void __wake_up_locked_key(struct wait_queue_head *wq_head, unsigned int mode, void *key); |
| 214 | void __wake_up_locked_key_bookmark(struct wait_queue_head *wq_head, |
| 215 | unsigned int mode, void *key, wait_queue_entry_t *bookmark); |
| 216 | void __wake_up_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key); |
| 217 | void __wake_up_locked_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key); |
| 218 | void __wake_up_locked(struct wait_queue_head *wq_head, unsigned int mode, int nr); |
| 219 | void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode); |
| 220 | void __wake_up_pollfree(struct wait_queue_head *wq_head); |
| 221 | |
| 222 | #define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL) |
| 223 | #define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL) |
| 224 | #define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL) |
| 225 | #define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL, 1) |
| 226 | #define wake_up_all_locked(x) __wake_up_locked((x), TASK_NORMAL, 0) |
| 227 | |
| 228 | #define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL) |
| 229 | #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL) |
| 230 | #define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL) |
| 231 | #define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE) |
| 232 | |
| 233 | /* |
| 234 | * Wakeup macros to be used to report events to the targets. |
| 235 | */ |
| 236 | #define poll_to_key(m) ((void *)(__force uintptr_t)(__poll_t)(m)) |
| 237 | #define key_to_poll(m) ((__force __poll_t)(uintptr_t)(void *)(m)) |
| 238 | #define wake_up_poll(x, m) \ |
| 239 | __wake_up(x, TASK_NORMAL, 1, poll_to_key(m)) |
| 240 | #define wake_up_locked_poll(x, m) \ |
| 241 | __wake_up_locked_key((x), TASK_NORMAL, poll_to_key(m)) |
| 242 | #define wake_up_interruptible_poll(x, m) \ |
| 243 | __wake_up(x, TASK_INTERRUPTIBLE, 1, poll_to_key(m)) |
| 244 | #define wake_up_interruptible_sync_poll(x, m) \ |
| 245 | __wake_up_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m)) |
| 246 | #define wake_up_interruptible_sync_poll_locked(x, m) \ |
| 247 | __wake_up_locked_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m)) |
| 248 | |
| 249 | /** |
| 250 | * wake_up_pollfree - signal that a polled waitqueue is going away |
| 251 | * @wq_head: the wait queue head |
| 252 | * |
| 253 | * In the very rare cases where a ->poll() implementation uses a waitqueue whose |
| 254 | * lifetime is tied to a task rather than to the 'struct file' being polled, |
| 255 | * this function must be called before the waitqueue is freed so that |
| 256 | * non-blocking polls (e.g. epoll) are notified that the queue is going away. |
| 257 | * |
| 258 | * The caller must also RCU-delay the freeing of the wait_queue_head, e.g. via |
| 259 | * an explicit synchronize_rcu() or call_rcu(), or via SLAB_TYPESAFE_BY_RCU. |
| 260 | */ |
| 261 | static inline void wake_up_pollfree(struct wait_queue_head *wq_head) |
| 262 | { |
| 263 | /* |
| 264 | * For performance reasons, we don't always take the queue lock here. |
| 265 | * Therefore, we might race with someone removing the last entry from |
| 266 | * the queue, and proceed while they still hold the queue lock. |
| 267 | * However, rcu_read_lock() is required to be held in such cases, so we |
| 268 | * can safely proceed with an RCU-delayed free. |
| 269 | */ |
| 270 | if (waitqueue_active(wq_head)) |
| 271 | __wake_up_pollfree(wq_head); |
| 272 | } |
| 273 | |
| 274 | #define ___wait_cond_timeout(condition) \ |
| 275 | ({ \ |
| 276 | bool __cond = (condition); \ |
| 277 | if (__cond && !__ret) \ |
| 278 | __ret = 1; \ |
| 279 | __cond || !__ret; \ |
| 280 | }) |
| 281 | |
| 282 | #define ___wait_is_interruptible(state) \ |
| 283 | (!__builtin_constant_p(state) || \ |
| 284 | (state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL))) |
| 285 | |
| 286 | extern void init_wait_entry(struct wait_queue_entry *wq_entry, int flags); |
| 287 | |
| 288 | /* |
| 289 | * The below macro ___wait_event() has an explicit shadow of the __ret |
| 290 | * variable when used from the wait_event_*() macros. |
| 291 | * |
| 292 | * This is so that both can use the ___wait_cond_timeout() construct |
| 293 | * to wrap the condition. |
| 294 | * |
| 295 | * The type inconsistency of the wait_event_*() __ret variable is also |
| 296 | * on purpose; we use long where we can return timeout values and int |
| 297 | * otherwise. |
| 298 | */ |
| 299 | |
| 300 | #define ___wait_event(wq_head, condition, state, exclusive, ret, cmd) \ |
| 301 | ({ \ |
| 302 | __label__ __out; \ |
| 303 | struct wait_queue_entry __wq_entry; \ |
| 304 | long __ret = ret; /* explicit shadow */ \ |
| 305 | \ |
| 306 | init_wait_entry(&__wq_entry, exclusive ? WQ_FLAG_EXCLUSIVE : 0); \ |
| 307 | for (;;) { \ |
| 308 | long __int = prepare_to_wait_event(&wq_head, &__wq_entry, state);\ |
| 309 | \ |
| 310 | if (condition) \ |
| 311 | break; \ |
| 312 | \ |
| 313 | if (___wait_is_interruptible(state) && __int) { \ |
| 314 | __ret = __int; \ |
| 315 | goto __out; \ |
| 316 | } \ |
| 317 | \ |
| 318 | cmd; \ |
| 319 | } \ |
| 320 | finish_wait(&wq_head, &__wq_entry); \ |
| 321 | __out: __ret; \ |
| 322 | }) |
| 323 | |
| 324 | #define __wait_event(wq_head, condition) \ |
| 325 | (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ |
| 326 | schedule()) |
| 327 | |
| 328 | /** |
| 329 | * wait_event - sleep until a condition gets true |
| 330 | * @wq_head: the waitqueue to wait on |
| 331 | * @condition: a C expression for the event to wait for |
| 332 | * |
| 333 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the |
| 334 | * @condition evaluates to true. The @condition is checked each time |
| 335 | * the waitqueue @wq_head is woken up. |
| 336 | * |
| 337 | * wake_up() has to be called after changing any variable that could |
| 338 | * change the result of the wait condition. |
| 339 | */ |
| 340 | #define wait_event(wq_head, condition) \ |
| 341 | do { \ |
| 342 | might_sleep(); \ |
| 343 | if (condition) \ |
| 344 | break; \ |
| 345 | __wait_event(wq_head, condition); \ |
| 346 | } while (0) |
| 347 | |
| 348 | #define __io_wait_event(wq_head, condition) \ |
| 349 | (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ |
| 350 | io_schedule()) |
| 351 | |
| 352 | /* |
| 353 | * io_wait_event() -- like wait_event() but with io_schedule() |
| 354 | */ |
| 355 | #define io_wait_event(wq_head, condition) \ |
| 356 | do { \ |
| 357 | might_sleep(); \ |
| 358 | if (condition) \ |
| 359 | break; \ |
| 360 | __io_wait_event(wq_head, condition); \ |
| 361 | } while (0) |
| 362 | |
| 363 | #define __wait_event_freezable(wq_head, condition) \ |
| 364 | ___wait_event(wq_head, condition, (TASK_INTERRUPTIBLE|TASK_FREEZABLE), \ |
| 365 | 0, 0, schedule()) |
| 366 | |
| 367 | /** |
| 368 | * wait_event_freezable - sleep (or freeze) until a condition gets true |
| 369 | * @wq_head: the waitqueue to wait on |
| 370 | * @condition: a C expression for the event to wait for |
| 371 | * |
| 372 | * The process is put to sleep (TASK_INTERRUPTIBLE -- so as not to contribute |
| 373 | * to system load) until the @condition evaluates to true. The |
| 374 | * @condition is checked each time the waitqueue @wq_head is woken up. |
| 375 | * |
| 376 | * wake_up() has to be called after changing any variable that could |
| 377 | * change the result of the wait condition. |
| 378 | */ |
| 379 | #define wait_event_freezable(wq_head, condition) \ |
| 380 | ({ \ |
| 381 | int __ret = 0; \ |
| 382 | might_sleep(); \ |
| 383 | if (!(condition)) \ |
| 384 | __ret = __wait_event_freezable(wq_head, condition); \ |
| 385 | __ret; \ |
| 386 | }) |
| 387 | |
| 388 | #define __wait_event_timeout(wq_head, condition, timeout) \ |
| 389 | ___wait_event(wq_head, ___wait_cond_timeout(condition), \ |
| 390 | TASK_UNINTERRUPTIBLE, 0, timeout, \ |
| 391 | __ret = schedule_timeout(__ret)) |
| 392 | |
| 393 | /** |
| 394 | * wait_event_timeout - sleep until a condition gets true or a timeout elapses |
| 395 | * @wq_head: the waitqueue to wait on |
| 396 | * @condition: a C expression for the event to wait for |
| 397 | * @timeout: timeout, in jiffies |
| 398 | * |
| 399 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the |
| 400 | * @condition evaluates to true. The @condition is checked each time |
| 401 | * the waitqueue @wq_head is woken up. |
| 402 | * |
| 403 | * wake_up() has to be called after changing any variable that could |
| 404 | * change the result of the wait condition. |
| 405 | * |
| 406 | * Returns: |
| 407 | * 0 if the @condition evaluated to %false after the @timeout elapsed, |
| 408 | * 1 if the @condition evaluated to %true after the @timeout elapsed, |
| 409 | * or the remaining jiffies (at least 1) if the @condition evaluated |
| 410 | * to %true before the @timeout elapsed. |
| 411 | */ |
| 412 | #define wait_event_timeout(wq_head, condition, timeout) \ |
| 413 | ({ \ |
| 414 | long __ret = timeout; \ |
| 415 | might_sleep(); \ |
| 416 | if (!___wait_cond_timeout(condition)) \ |
| 417 | __ret = __wait_event_timeout(wq_head, condition, timeout); \ |
| 418 | __ret; \ |
| 419 | }) |
| 420 | |
| 421 | #define __wait_event_freezable_timeout(wq_head, condition, timeout) \ |
| 422 | ___wait_event(wq_head, ___wait_cond_timeout(condition), \ |
| 423 | (TASK_INTERRUPTIBLE|TASK_FREEZABLE), 0, timeout, \ |
| 424 | __ret = schedule_timeout(__ret)) |
| 425 | |
| 426 | /* |
| 427 | * like wait_event_timeout() -- except it uses TASK_INTERRUPTIBLE to avoid |
| 428 | * increasing load and is freezable. |
| 429 | */ |
| 430 | #define wait_event_freezable_timeout(wq_head, condition, timeout) \ |
| 431 | ({ \ |
| 432 | long __ret = timeout; \ |
| 433 | might_sleep(); \ |
| 434 | if (!___wait_cond_timeout(condition)) \ |
| 435 | __ret = __wait_event_freezable_timeout(wq_head, condition, timeout); \ |
| 436 | __ret; \ |
| 437 | }) |
| 438 | |
| 439 | #define __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2) \ |
| 440 | (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 1, 0, \ |
| 441 | cmd1; schedule(); cmd2) |
| 442 | /* |
| 443 | * Just like wait_event_cmd(), except it sets exclusive flag |
| 444 | */ |
| 445 | #define wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2) \ |
| 446 | do { \ |
| 447 | if (condition) \ |
| 448 | break; \ |
| 449 | __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2); \ |
| 450 | } while (0) |
| 451 | |
| 452 | #define __wait_event_cmd(wq_head, condition, cmd1, cmd2) \ |
| 453 | (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ |
| 454 | cmd1; schedule(); cmd2) |
| 455 | |
| 456 | /** |
| 457 | * wait_event_cmd - sleep until a condition gets true |
| 458 | * @wq_head: the waitqueue to wait on |
| 459 | * @condition: a C expression for the event to wait for |
| 460 | * @cmd1: the command will be executed before sleep |
| 461 | * @cmd2: the command will be executed after sleep |
| 462 | * |
| 463 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the |
| 464 | * @condition evaluates to true. The @condition is checked each time |
| 465 | * the waitqueue @wq_head is woken up. |
| 466 | * |
| 467 | * wake_up() has to be called after changing any variable that could |
| 468 | * change the result of the wait condition. |
| 469 | */ |
| 470 | #define wait_event_cmd(wq_head, condition, cmd1, cmd2) \ |
| 471 | do { \ |
| 472 | if (condition) \ |
| 473 | break; \ |
| 474 | __wait_event_cmd(wq_head, condition, cmd1, cmd2); \ |
| 475 | } while (0) |
| 476 | |
| 477 | #define __wait_event_interruptible(wq_head, condition) \ |
| 478 | ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0, \ |
| 479 | schedule()) |
| 480 | |
| 481 | /** |
| 482 | * wait_event_interruptible - sleep until a condition gets true |
| 483 | * @wq_head: the waitqueue to wait on |
| 484 | * @condition: a C expression for the event to wait for |
| 485 | * |
| 486 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the |
| 487 | * @condition evaluates to true or a signal is received. |
| 488 | * The @condition is checked each time the waitqueue @wq_head is woken up. |
| 489 | * |
| 490 | * wake_up() has to be called after changing any variable that could |
| 491 | * change the result of the wait condition. |
| 492 | * |
| 493 | * The function will return -ERESTARTSYS if it was interrupted by a |
| 494 | * signal and 0 if @condition evaluated to true. |
| 495 | */ |
| 496 | #define wait_event_interruptible(wq_head, condition) \ |
| 497 | ({ \ |
| 498 | int __ret = 0; \ |
| 499 | might_sleep(); \ |
| 500 | if (!(condition)) \ |
| 501 | __ret = __wait_event_interruptible(wq_head, condition); \ |
| 502 | __ret; \ |
| 503 | }) |
| 504 | |
| 505 | #define __wait_event_interruptible_timeout(wq_head, condition, timeout) \ |
| 506 | ___wait_event(wq_head, ___wait_cond_timeout(condition), \ |
| 507 | TASK_INTERRUPTIBLE, 0, timeout, \ |
| 508 | __ret = schedule_timeout(__ret)) |
| 509 | |
| 510 | /** |
| 511 | * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses |
| 512 | * @wq_head: the waitqueue to wait on |
| 513 | * @condition: a C expression for the event to wait for |
| 514 | * @timeout: timeout, in jiffies |
| 515 | * |
| 516 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the |
| 517 | * @condition evaluates to true or a signal is received. |
| 518 | * The @condition is checked each time the waitqueue @wq_head is woken up. |
| 519 | * |
| 520 | * wake_up() has to be called after changing any variable that could |
| 521 | * change the result of the wait condition. |
| 522 | * |
| 523 | * Returns: |
| 524 | * 0 if the @condition evaluated to %false after the @timeout elapsed, |
| 525 | * 1 if the @condition evaluated to %true after the @timeout elapsed, |
| 526 | * the remaining jiffies (at least 1) if the @condition evaluated |
| 527 | * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was |
| 528 | * interrupted by a signal. |
| 529 | */ |
| 530 | #define wait_event_interruptible_timeout(wq_head, condition, timeout) \ |
| 531 | ({ \ |
| 532 | long __ret = timeout; \ |
| 533 | might_sleep(); \ |
| 534 | if (!___wait_cond_timeout(condition)) \ |
| 535 | __ret = __wait_event_interruptible_timeout(wq_head, \ |
| 536 | condition, timeout); \ |
| 537 | __ret; \ |
| 538 | }) |
| 539 | |
| 540 | #define __wait_event_hrtimeout(wq_head, condition, timeout, state) \ |
| 541 | ({ \ |
| 542 | int __ret = 0; \ |
| 543 | struct hrtimer_sleeper __t; \ |
| 544 | \ |
| 545 | hrtimer_init_sleeper_on_stack(&__t, CLOCK_MONOTONIC, \ |
| 546 | HRTIMER_MODE_REL); \ |
| 547 | if ((timeout) != KTIME_MAX) { \ |
| 548 | hrtimer_set_expires_range_ns(&__t.timer, timeout, \ |
| 549 | current->timer_slack_ns); \ |
| 550 | hrtimer_sleeper_start_expires(&__t, HRTIMER_MODE_REL); \ |
| 551 | } \ |
| 552 | \ |
| 553 | __ret = ___wait_event(wq_head, condition, state, 0, 0, \ |
| 554 | if (!__t.task) { \ |
| 555 | __ret = -ETIME; \ |
| 556 | break; \ |
| 557 | } \ |
| 558 | schedule()); \ |
| 559 | \ |
| 560 | hrtimer_cancel(&__t.timer); \ |
| 561 | destroy_hrtimer_on_stack(&__t.timer); \ |
| 562 | __ret; \ |
| 563 | }) |
| 564 | |
| 565 | /** |
| 566 | * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses |
| 567 | * @wq_head: the waitqueue to wait on |
| 568 | * @condition: a C expression for the event to wait for |
| 569 | * @timeout: timeout, as a ktime_t |
| 570 | * |
| 571 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the |
| 572 | * @condition evaluates to true or a signal is received. |
| 573 | * The @condition is checked each time the waitqueue @wq_head is woken up. |
| 574 | * |
| 575 | * wake_up() has to be called after changing any variable that could |
| 576 | * change the result of the wait condition. |
| 577 | * |
| 578 | * The function returns 0 if @condition became true, or -ETIME if the timeout |
| 579 | * elapsed. |
| 580 | */ |
| 581 | #define wait_event_hrtimeout(wq_head, condition, timeout) \ |
| 582 | ({ \ |
| 583 | int __ret = 0; \ |
| 584 | might_sleep(); \ |
| 585 | if (!(condition)) \ |
| 586 | __ret = __wait_event_hrtimeout(wq_head, condition, timeout, \ |
| 587 | TASK_UNINTERRUPTIBLE); \ |
| 588 | __ret; \ |
| 589 | }) |
| 590 | |
| 591 | /** |
| 592 | * wait_event_interruptible_hrtimeout - sleep until a condition gets true or a timeout elapses |
| 593 | * @wq: the waitqueue to wait on |
| 594 | * @condition: a C expression for the event to wait for |
| 595 | * @timeout: timeout, as a ktime_t |
| 596 | * |
| 597 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the |
| 598 | * @condition evaluates to true or a signal is received. |
| 599 | * The @condition is checked each time the waitqueue @wq is woken up. |
| 600 | * |
| 601 | * wake_up() has to be called after changing any variable that could |
| 602 | * change the result of the wait condition. |
| 603 | * |
| 604 | * The function returns 0 if @condition became true, -ERESTARTSYS if it was |
| 605 | * interrupted by a signal, or -ETIME if the timeout elapsed. |
| 606 | */ |
| 607 | #define wait_event_interruptible_hrtimeout(wq, condition, timeout) \ |
| 608 | ({ \ |
| 609 | long __ret = 0; \ |
| 610 | might_sleep(); \ |
| 611 | if (!(condition)) \ |
| 612 | __ret = __wait_event_hrtimeout(wq, condition, timeout, \ |
| 613 | TASK_INTERRUPTIBLE); \ |
| 614 | __ret; \ |
| 615 | }) |
| 616 | |
| 617 | #define __wait_event_interruptible_exclusive(wq, condition) \ |
| 618 | ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \ |
| 619 | schedule()) |
| 620 | |
| 621 | #define wait_event_interruptible_exclusive(wq, condition) \ |
| 622 | ({ \ |
| 623 | int __ret = 0; \ |
| 624 | might_sleep(); \ |
| 625 | if (!(condition)) \ |
| 626 | __ret = __wait_event_interruptible_exclusive(wq, condition); \ |
| 627 | __ret; \ |
| 628 | }) |
| 629 | |
| 630 | #define __wait_event_killable_exclusive(wq, condition) \ |
| 631 | ___wait_event(wq, condition, TASK_KILLABLE, 1, 0, \ |
| 632 | schedule()) |
| 633 | |
| 634 | #define wait_event_killable_exclusive(wq, condition) \ |
| 635 | ({ \ |
| 636 | int __ret = 0; \ |
| 637 | might_sleep(); \ |
| 638 | if (!(condition)) \ |
| 639 | __ret = __wait_event_killable_exclusive(wq, condition); \ |
| 640 | __ret; \ |
| 641 | }) |
| 642 | |
| 643 | |
| 644 | #define __wait_event_freezable_exclusive(wq, condition) \ |
| 645 | ___wait_event(wq, condition, (TASK_INTERRUPTIBLE|TASK_FREEZABLE), 1, 0,\ |
| 646 | schedule()) |
| 647 | |
| 648 | #define wait_event_freezable_exclusive(wq, condition) \ |
| 649 | ({ \ |
| 650 | int __ret = 0; \ |
| 651 | might_sleep(); \ |
| 652 | if (!(condition)) \ |
| 653 | __ret = __wait_event_freezable_exclusive(wq, condition); \ |
| 654 | __ret; \ |
| 655 | }) |
| 656 | |
| 657 | /** |
| 658 | * wait_event_idle - wait for a condition without contributing to system load |
| 659 | * @wq_head: the waitqueue to wait on |
| 660 | * @condition: a C expression for the event to wait for |
| 661 | * |
| 662 | * The process is put to sleep (TASK_IDLE) until the |
| 663 | * @condition evaluates to true. |
| 664 | * The @condition is checked each time the waitqueue @wq_head is woken up. |
| 665 | * |
| 666 | * wake_up() has to be called after changing any variable that could |
| 667 | * change the result of the wait condition. |
| 668 | * |
| 669 | */ |
| 670 | #define wait_event_idle(wq_head, condition) \ |
| 671 | do { \ |
| 672 | might_sleep(); \ |
| 673 | if (!(condition)) \ |
| 674 | ___wait_event(wq_head, condition, TASK_IDLE, 0, 0, schedule()); \ |
| 675 | } while (0) |
| 676 | |
| 677 | /** |
| 678 | * wait_event_idle_exclusive - wait for a condition with contributing to system load |
| 679 | * @wq_head: the waitqueue to wait on |
| 680 | * @condition: a C expression for the event to wait for |
| 681 | * |
| 682 | * The process is put to sleep (TASK_IDLE) until the |
| 683 | * @condition evaluates to true. |
| 684 | * The @condition is checked each time the waitqueue @wq_head is woken up. |
| 685 | * |
| 686 | * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag |
| 687 | * set thus if other processes wait on the same list, when this |
| 688 | * process is woken further processes are not considered. |
| 689 | * |
| 690 | * wake_up() has to be called after changing any variable that could |
| 691 | * change the result of the wait condition. |
| 692 | * |
| 693 | */ |
| 694 | #define wait_event_idle_exclusive(wq_head, condition) \ |
| 695 | do { \ |
| 696 | might_sleep(); \ |
| 697 | if (!(condition)) \ |
| 698 | ___wait_event(wq_head, condition, TASK_IDLE, 1, 0, schedule()); \ |
| 699 | } while (0) |
| 700 | |
| 701 | #define __wait_event_idle_timeout(wq_head, condition, timeout) \ |
| 702 | ___wait_event(wq_head, ___wait_cond_timeout(condition), \ |
| 703 | TASK_IDLE, 0, timeout, \ |
| 704 | __ret = schedule_timeout(__ret)) |
| 705 | |
| 706 | /** |
| 707 | * wait_event_idle_timeout - sleep without load until a condition becomes true or a timeout elapses |
| 708 | * @wq_head: the waitqueue to wait on |
| 709 | * @condition: a C expression for the event to wait for |
| 710 | * @timeout: timeout, in jiffies |
| 711 | * |
| 712 | * The process is put to sleep (TASK_IDLE) until the |
| 713 | * @condition evaluates to true. The @condition is checked each time |
| 714 | * the waitqueue @wq_head is woken up. |
| 715 | * |
| 716 | * wake_up() has to be called after changing any variable that could |
| 717 | * change the result of the wait condition. |
| 718 | * |
| 719 | * Returns: |
| 720 | * 0 if the @condition evaluated to %false after the @timeout elapsed, |
| 721 | * 1 if the @condition evaluated to %true after the @timeout elapsed, |
| 722 | * or the remaining jiffies (at least 1) if the @condition evaluated |
| 723 | * to %true before the @timeout elapsed. |
| 724 | */ |
| 725 | #define wait_event_idle_timeout(wq_head, condition, timeout) \ |
| 726 | ({ \ |
| 727 | long __ret = timeout; \ |
| 728 | might_sleep(); \ |
| 729 | if (!___wait_cond_timeout(condition)) \ |
| 730 | __ret = __wait_event_idle_timeout(wq_head, condition, timeout); \ |
| 731 | __ret; \ |
| 732 | }) |
| 733 | |
| 734 | #define __wait_event_idle_exclusive_timeout(wq_head, condition, timeout) \ |
| 735 | ___wait_event(wq_head, ___wait_cond_timeout(condition), \ |
| 736 | TASK_IDLE, 1, timeout, \ |
| 737 | __ret = schedule_timeout(__ret)) |
| 738 | |
| 739 | /** |
| 740 | * wait_event_idle_exclusive_timeout - sleep without load until a condition becomes true or a timeout elapses |
| 741 | * @wq_head: the waitqueue to wait on |
| 742 | * @condition: a C expression for the event to wait for |
| 743 | * @timeout: timeout, in jiffies |
| 744 | * |
| 745 | * The process is put to sleep (TASK_IDLE) until the |
| 746 | * @condition evaluates to true. The @condition is checked each time |
| 747 | * the waitqueue @wq_head is woken up. |
| 748 | * |
| 749 | * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag |
| 750 | * set thus if other processes wait on the same list, when this |
| 751 | * process is woken further processes are not considered. |
| 752 | * |
| 753 | * wake_up() has to be called after changing any variable that could |
| 754 | * change the result of the wait condition. |
| 755 | * |
| 756 | * Returns: |
| 757 | * 0 if the @condition evaluated to %false after the @timeout elapsed, |
| 758 | * 1 if the @condition evaluated to %true after the @timeout elapsed, |
| 759 | * or the remaining jiffies (at least 1) if the @condition evaluated |
| 760 | * to %true before the @timeout elapsed. |
| 761 | */ |
| 762 | #define wait_event_idle_exclusive_timeout(wq_head, condition, timeout) \ |
| 763 | ({ \ |
| 764 | long __ret = timeout; \ |
| 765 | might_sleep(); \ |
| 766 | if (!___wait_cond_timeout(condition)) \ |
| 767 | __ret = __wait_event_idle_exclusive_timeout(wq_head, condition, timeout);\ |
| 768 | __ret; \ |
| 769 | }) |
| 770 | |
| 771 | extern int do_wait_intr(wait_queue_head_t *, wait_queue_entry_t *); |
| 772 | extern int do_wait_intr_irq(wait_queue_head_t *, wait_queue_entry_t *); |
| 773 | |
| 774 | #define __wait_event_interruptible_locked(wq, condition, exclusive, fn) \ |
| 775 | ({ \ |
| 776 | int __ret; \ |
| 777 | DEFINE_WAIT(__wait); \ |
| 778 | if (exclusive) \ |
| 779 | __wait.flags |= WQ_FLAG_EXCLUSIVE; \ |
| 780 | do { \ |
| 781 | __ret = fn(&(wq), &__wait); \ |
| 782 | if (__ret) \ |
| 783 | break; \ |
| 784 | } while (!(condition)); \ |
| 785 | __remove_wait_queue(&(wq), &__wait); \ |
| 786 | __set_current_state(TASK_RUNNING); \ |
| 787 | __ret; \ |
| 788 | }) |
| 789 | |
| 790 | |
| 791 | /** |
| 792 | * wait_event_interruptible_locked - sleep until a condition gets true |
| 793 | * @wq: the waitqueue to wait on |
| 794 | * @condition: a C expression for the event to wait for |
| 795 | * |
| 796 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the |
| 797 | * @condition evaluates to true or a signal is received. |
| 798 | * The @condition is checked each time the waitqueue @wq is woken up. |
| 799 | * |
| 800 | * It must be called with wq.lock being held. This spinlock is |
| 801 | * unlocked while sleeping but @condition testing is done while lock |
| 802 | * is held and when this macro exits the lock is held. |
| 803 | * |
| 804 | * The lock is locked/unlocked using spin_lock()/spin_unlock() |
| 805 | * functions which must match the way they are locked/unlocked outside |
| 806 | * of this macro. |
| 807 | * |
| 808 | * wake_up_locked() has to be called after changing any variable that could |
| 809 | * change the result of the wait condition. |
| 810 | * |
| 811 | * The function will return -ERESTARTSYS if it was interrupted by a |
| 812 | * signal and 0 if @condition evaluated to true. |
| 813 | */ |
| 814 | #define wait_event_interruptible_locked(wq, condition) \ |
| 815 | ((condition) \ |
| 816 | ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr)) |
| 817 | |
| 818 | /** |
| 819 | * wait_event_interruptible_locked_irq - sleep until a condition gets true |
| 820 | * @wq: the waitqueue to wait on |
| 821 | * @condition: a C expression for the event to wait for |
| 822 | * |
| 823 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the |
| 824 | * @condition evaluates to true or a signal is received. |
| 825 | * The @condition is checked each time the waitqueue @wq is woken up. |
| 826 | * |
| 827 | * It must be called with wq.lock being held. This spinlock is |
| 828 | * unlocked while sleeping but @condition testing is done while lock |
| 829 | * is held and when this macro exits the lock is held. |
| 830 | * |
| 831 | * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq() |
| 832 | * functions which must match the way they are locked/unlocked outside |
| 833 | * of this macro. |
| 834 | * |
| 835 | * wake_up_locked() has to be called after changing any variable that could |
| 836 | * change the result of the wait condition. |
| 837 | * |
| 838 | * The function will return -ERESTARTSYS if it was interrupted by a |
| 839 | * signal and 0 if @condition evaluated to true. |
| 840 | */ |
| 841 | #define wait_event_interruptible_locked_irq(wq, condition) \ |
| 842 | ((condition) \ |
| 843 | ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr_irq)) |
| 844 | |
| 845 | /** |
| 846 | * wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true |
| 847 | * @wq: the waitqueue to wait on |
| 848 | * @condition: a C expression for the event to wait for |
| 849 | * |
| 850 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the |
| 851 | * @condition evaluates to true or a signal is received. |
| 852 | * The @condition is checked each time the waitqueue @wq is woken up. |
| 853 | * |
| 854 | * It must be called with wq.lock being held. This spinlock is |
| 855 | * unlocked while sleeping but @condition testing is done while lock |
| 856 | * is held and when this macro exits the lock is held. |
| 857 | * |
| 858 | * The lock is locked/unlocked using spin_lock()/spin_unlock() |
| 859 | * functions which must match the way they are locked/unlocked outside |
| 860 | * of this macro. |
| 861 | * |
| 862 | * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag |
| 863 | * set thus when other process waits process on the list if this |
| 864 | * process is awaken further processes are not considered. |
| 865 | * |
| 866 | * wake_up_locked() has to be called after changing any variable that could |
| 867 | * change the result of the wait condition. |
| 868 | * |
| 869 | * The function will return -ERESTARTSYS if it was interrupted by a |
| 870 | * signal and 0 if @condition evaluated to true. |
| 871 | */ |
| 872 | #define wait_event_interruptible_exclusive_locked(wq, condition) \ |
| 873 | ((condition) \ |
| 874 | ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr)) |
| 875 | |
| 876 | /** |
| 877 | * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true |
| 878 | * @wq: the waitqueue to wait on |
| 879 | * @condition: a C expression for the event to wait for |
| 880 | * |
| 881 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the |
| 882 | * @condition evaluates to true or a signal is received. |
| 883 | * The @condition is checked each time the waitqueue @wq is woken up. |
| 884 | * |
| 885 | * It must be called with wq.lock being held. This spinlock is |
| 886 | * unlocked while sleeping but @condition testing is done while lock |
| 887 | * is held and when this macro exits the lock is held. |
| 888 | * |
| 889 | * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq() |
| 890 | * functions which must match the way they are locked/unlocked outside |
| 891 | * of this macro. |
| 892 | * |
| 893 | * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag |
| 894 | * set thus when other process waits process on the list if this |
| 895 | * process is awaken further processes are not considered. |
| 896 | * |
| 897 | * wake_up_locked() has to be called after changing any variable that could |
| 898 | * change the result of the wait condition. |
| 899 | * |
| 900 | * The function will return -ERESTARTSYS if it was interrupted by a |
| 901 | * signal and 0 if @condition evaluated to true. |
| 902 | */ |
| 903 | #define wait_event_interruptible_exclusive_locked_irq(wq, condition) \ |
| 904 | ((condition) \ |
| 905 | ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr_irq)) |
| 906 | |
| 907 | |
| 908 | #define __wait_event_killable(wq, condition) \ |
| 909 | ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule()) |
| 910 | |
| 911 | /** |
| 912 | * wait_event_killable - sleep until a condition gets true |
| 913 | * @wq_head: the waitqueue to wait on |
| 914 | * @condition: a C expression for the event to wait for |
| 915 | * |
| 916 | * The process is put to sleep (TASK_KILLABLE) until the |
| 917 | * @condition evaluates to true or a signal is received. |
| 918 | * The @condition is checked each time the waitqueue @wq_head is woken up. |
| 919 | * |
| 920 | * wake_up() has to be called after changing any variable that could |
| 921 | * change the result of the wait condition. |
| 922 | * |
| 923 | * The function will return -ERESTARTSYS if it was interrupted by a |
| 924 | * signal and 0 if @condition evaluated to true. |
| 925 | */ |
| 926 | #define wait_event_killable(wq_head, condition) \ |
| 927 | ({ \ |
| 928 | int __ret = 0; \ |
| 929 | might_sleep(); \ |
| 930 | if (!(condition)) \ |
| 931 | __ret = __wait_event_killable(wq_head, condition); \ |
| 932 | __ret; \ |
| 933 | }) |
| 934 | |
| 935 | #define __wait_event_state(wq, condition, state) \ |
| 936 | ___wait_event(wq, condition, state, 0, 0, schedule()) |
| 937 | |
| 938 | /** |
| 939 | * wait_event_state - sleep until a condition gets true |
| 940 | * @wq_head: the waitqueue to wait on |
| 941 | * @condition: a C expression for the event to wait for |
| 942 | * @state: state to sleep in |
| 943 | * |
| 944 | * The process is put to sleep (@state) until the @condition evaluates to true |
| 945 | * or a signal is received (when allowed by @state). The @condition is checked |
| 946 | * each time the waitqueue @wq_head is woken up. |
| 947 | * |
| 948 | * wake_up() has to be called after changing any variable that could |
| 949 | * change the result of the wait condition. |
| 950 | * |
| 951 | * The function will return -ERESTARTSYS if it was interrupted by a signal |
| 952 | * (when allowed by @state) and 0 if @condition evaluated to true. |
| 953 | */ |
| 954 | #define wait_event_state(wq_head, condition, state) \ |
| 955 | ({ \ |
| 956 | int __ret = 0; \ |
| 957 | might_sleep(); \ |
| 958 | if (!(condition)) \ |
| 959 | __ret = __wait_event_state(wq_head, condition, state); \ |
| 960 | __ret; \ |
| 961 | }) |
| 962 | |
| 963 | #define __wait_event_killable_timeout(wq_head, condition, timeout) \ |
| 964 | ___wait_event(wq_head, ___wait_cond_timeout(condition), \ |
| 965 | TASK_KILLABLE, 0, timeout, \ |
| 966 | __ret = schedule_timeout(__ret)) |
| 967 | |
| 968 | /** |
| 969 | * wait_event_killable_timeout - sleep until a condition gets true or a timeout elapses |
| 970 | * @wq_head: the waitqueue to wait on |
| 971 | * @condition: a C expression for the event to wait for |
| 972 | * @timeout: timeout, in jiffies |
| 973 | * |
| 974 | * The process is put to sleep (TASK_KILLABLE) until the |
| 975 | * @condition evaluates to true or a kill signal is received. |
| 976 | * The @condition is checked each time the waitqueue @wq_head is woken up. |
| 977 | * |
| 978 | * wake_up() has to be called after changing any variable that could |
| 979 | * change the result of the wait condition. |
| 980 | * |
| 981 | * Returns: |
| 982 | * 0 if the @condition evaluated to %false after the @timeout elapsed, |
| 983 | * 1 if the @condition evaluated to %true after the @timeout elapsed, |
| 984 | * the remaining jiffies (at least 1) if the @condition evaluated |
| 985 | * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was |
| 986 | * interrupted by a kill signal. |
| 987 | * |
| 988 | * Only kill signals interrupt this process. |
| 989 | */ |
| 990 | #define wait_event_killable_timeout(wq_head, condition, timeout) \ |
| 991 | ({ \ |
| 992 | long __ret = timeout; \ |
| 993 | might_sleep(); \ |
| 994 | if (!___wait_cond_timeout(condition)) \ |
| 995 | __ret = __wait_event_killable_timeout(wq_head, \ |
| 996 | condition, timeout); \ |
| 997 | __ret; \ |
| 998 | }) |
| 999 | |
| 1000 | |
| 1001 | #define __wait_event_lock_irq(wq_head, condition, lock, cmd) \ |
| 1002 | (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ |
| 1003 | spin_unlock_irq(&lock); \ |
| 1004 | cmd; \ |
| 1005 | schedule(); \ |
| 1006 | spin_lock_irq(&lock)) |
| 1007 | |
| 1008 | /** |
| 1009 | * wait_event_lock_irq_cmd - sleep until a condition gets true. The |
| 1010 | * condition is checked under the lock. This |
| 1011 | * is expected to be called with the lock |
| 1012 | * taken. |
| 1013 | * @wq_head: the waitqueue to wait on |
| 1014 | * @condition: a C expression for the event to wait for |
| 1015 | * @lock: a locked spinlock_t, which will be released before cmd |
| 1016 | * and schedule() and reacquired afterwards. |
| 1017 | * @cmd: a command which is invoked outside the critical section before |
| 1018 | * sleep |
| 1019 | * |
| 1020 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the |
| 1021 | * @condition evaluates to true. The @condition is checked each time |
| 1022 | * the waitqueue @wq_head is woken up. |
| 1023 | * |
| 1024 | * wake_up() has to be called after changing any variable that could |
| 1025 | * change the result of the wait condition. |
| 1026 | * |
| 1027 | * This is supposed to be called while holding the lock. The lock is |
| 1028 | * dropped before invoking the cmd and going to sleep and is reacquired |
| 1029 | * afterwards. |
| 1030 | */ |
| 1031 | #define wait_event_lock_irq_cmd(wq_head, condition, lock, cmd) \ |
| 1032 | do { \ |
| 1033 | if (condition) \ |
| 1034 | break; \ |
| 1035 | __wait_event_lock_irq(wq_head, condition, lock, cmd); \ |
| 1036 | } while (0) |
| 1037 | |
| 1038 | /** |
| 1039 | * wait_event_lock_irq - sleep until a condition gets true. The |
| 1040 | * condition is checked under the lock. This |
| 1041 | * is expected to be called with the lock |
| 1042 | * taken. |
| 1043 | * @wq_head: the waitqueue to wait on |
| 1044 | * @condition: a C expression for the event to wait for |
| 1045 | * @lock: a locked spinlock_t, which will be released before schedule() |
| 1046 | * and reacquired afterwards. |
| 1047 | * |
| 1048 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the |
| 1049 | * @condition evaluates to true. The @condition is checked each time |
| 1050 | * the waitqueue @wq_head is woken up. |
| 1051 | * |
| 1052 | * wake_up() has to be called after changing any variable that could |
| 1053 | * change the result of the wait condition. |
| 1054 | * |
| 1055 | * This is supposed to be called while holding the lock. The lock is |
| 1056 | * dropped before going to sleep and is reacquired afterwards. |
| 1057 | */ |
| 1058 | #define wait_event_lock_irq(wq_head, condition, lock) \ |
| 1059 | do { \ |
| 1060 | if (condition) \ |
| 1061 | break; \ |
| 1062 | __wait_event_lock_irq(wq_head, condition, lock, ); \ |
| 1063 | } while (0) |
| 1064 | |
| 1065 | |
| 1066 | #define __wait_event_interruptible_lock_irq(wq_head, condition, lock, cmd) \ |
| 1067 | ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0, \ |
| 1068 | spin_unlock_irq(&lock); \ |
| 1069 | cmd; \ |
| 1070 | schedule(); \ |
| 1071 | spin_lock_irq(&lock)) |
| 1072 | |
| 1073 | /** |
| 1074 | * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true. |
| 1075 | * The condition is checked under the lock. This is expected to |
| 1076 | * be called with the lock taken. |
| 1077 | * @wq_head: the waitqueue to wait on |
| 1078 | * @condition: a C expression for the event to wait for |
| 1079 | * @lock: a locked spinlock_t, which will be released before cmd and |
| 1080 | * schedule() and reacquired afterwards. |
| 1081 | * @cmd: a command which is invoked outside the critical section before |
| 1082 | * sleep |
| 1083 | * |
| 1084 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the |
| 1085 | * @condition evaluates to true or a signal is received. The @condition is |
| 1086 | * checked each time the waitqueue @wq_head is woken up. |
| 1087 | * |
| 1088 | * wake_up() has to be called after changing any variable that could |
| 1089 | * change the result of the wait condition. |
| 1090 | * |
| 1091 | * This is supposed to be called while holding the lock. The lock is |
| 1092 | * dropped before invoking the cmd and going to sleep and is reacquired |
| 1093 | * afterwards. |
| 1094 | * |
| 1095 | * The macro will return -ERESTARTSYS if it was interrupted by a signal |
| 1096 | * and 0 if @condition evaluated to true. |
| 1097 | */ |
| 1098 | #define wait_event_interruptible_lock_irq_cmd(wq_head, condition, lock, cmd) \ |
| 1099 | ({ \ |
| 1100 | int __ret = 0; \ |
| 1101 | if (!(condition)) \ |
| 1102 | __ret = __wait_event_interruptible_lock_irq(wq_head, \ |
| 1103 | condition, lock, cmd); \ |
| 1104 | __ret; \ |
| 1105 | }) |
| 1106 | |
| 1107 | /** |
| 1108 | * wait_event_interruptible_lock_irq - sleep until a condition gets true. |
| 1109 | * The condition is checked under the lock. This is expected |
| 1110 | * to be called with the lock taken. |
| 1111 | * @wq_head: the waitqueue to wait on |
| 1112 | * @condition: a C expression for the event to wait for |
| 1113 | * @lock: a locked spinlock_t, which will be released before schedule() |
| 1114 | * and reacquired afterwards. |
| 1115 | * |
| 1116 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the |
| 1117 | * @condition evaluates to true or signal is received. The @condition is |
| 1118 | * checked each time the waitqueue @wq_head is woken up. |
| 1119 | * |
| 1120 | * wake_up() has to be called after changing any variable that could |
| 1121 | * change the result of the wait condition. |
| 1122 | * |
| 1123 | * This is supposed to be called while holding the lock. The lock is |
| 1124 | * dropped before going to sleep and is reacquired afterwards. |
| 1125 | * |
| 1126 | * The macro will return -ERESTARTSYS if it was interrupted by a signal |
| 1127 | * and 0 if @condition evaluated to true. |
| 1128 | */ |
| 1129 | #define wait_event_interruptible_lock_irq(wq_head, condition, lock) \ |
| 1130 | ({ \ |
| 1131 | int __ret = 0; \ |
| 1132 | if (!(condition)) \ |
| 1133 | __ret = __wait_event_interruptible_lock_irq(wq_head, \ |
| 1134 | condition, lock,); \ |
| 1135 | __ret; \ |
| 1136 | }) |
| 1137 | |
| 1138 | #define __wait_event_lock_irq_timeout(wq_head, condition, lock, timeout, state) \ |
| 1139 | ___wait_event(wq_head, ___wait_cond_timeout(condition), \ |
| 1140 | state, 0, timeout, \ |
| 1141 | spin_unlock_irq(&lock); \ |
| 1142 | __ret = schedule_timeout(__ret); \ |
| 1143 | spin_lock_irq(&lock)); |
| 1144 | |
| 1145 | /** |
| 1146 | * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets |
| 1147 | * true or a timeout elapses. The condition is checked under |
| 1148 | * the lock. This is expected to be called with the lock taken. |
| 1149 | * @wq_head: the waitqueue to wait on |
| 1150 | * @condition: a C expression for the event to wait for |
| 1151 | * @lock: a locked spinlock_t, which will be released before schedule() |
| 1152 | * and reacquired afterwards. |
| 1153 | * @timeout: timeout, in jiffies |
| 1154 | * |
| 1155 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the |
| 1156 | * @condition evaluates to true or signal is received. The @condition is |
| 1157 | * checked each time the waitqueue @wq_head is woken up. |
| 1158 | * |
| 1159 | * wake_up() has to be called after changing any variable that could |
| 1160 | * change the result of the wait condition. |
| 1161 | * |
| 1162 | * This is supposed to be called while holding the lock. The lock is |
| 1163 | * dropped before going to sleep and is reacquired afterwards. |
| 1164 | * |
| 1165 | * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it |
| 1166 | * was interrupted by a signal, and the remaining jiffies otherwise |
| 1167 | * if the condition evaluated to true before the timeout elapsed. |
| 1168 | */ |
| 1169 | #define wait_event_interruptible_lock_irq_timeout(wq_head, condition, lock, \ |
| 1170 | timeout) \ |
| 1171 | ({ \ |
| 1172 | long __ret = timeout; \ |
| 1173 | if (!___wait_cond_timeout(condition)) \ |
| 1174 | __ret = __wait_event_lock_irq_timeout( \ |
| 1175 | wq_head, condition, lock, timeout, \ |
| 1176 | TASK_INTERRUPTIBLE); \ |
| 1177 | __ret; \ |
| 1178 | }) |
| 1179 | |
| 1180 | #define wait_event_lock_irq_timeout(wq_head, condition, lock, timeout) \ |
| 1181 | ({ \ |
| 1182 | long __ret = timeout; \ |
| 1183 | if (!___wait_cond_timeout(condition)) \ |
| 1184 | __ret = __wait_event_lock_irq_timeout( \ |
| 1185 | wq_head, condition, lock, timeout, \ |
| 1186 | TASK_UNINTERRUPTIBLE); \ |
| 1187 | __ret; \ |
| 1188 | }) |
| 1189 | |
| 1190 | /* |
| 1191 | * Waitqueues which are removed from the waitqueue_head at wakeup time |
| 1192 | */ |
| 1193 | void prepare_to_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state); |
| 1194 | bool prepare_to_wait_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state); |
| 1195 | long prepare_to_wait_event(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state); |
| 1196 | void finish_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); |
| 1197 | long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout); |
| 1198 | int woken_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key); |
| 1199 | int autoremove_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key); |
| 1200 | |
| 1201 | #define DEFINE_WAIT_FUNC(name, function) \ |
| 1202 | struct wait_queue_entry name = { \ |
| 1203 | .private = current, \ |
| 1204 | .func = function, \ |
| 1205 | .entry = LIST_HEAD_INIT((name).entry), \ |
| 1206 | } |
| 1207 | |
| 1208 | #define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function) |
| 1209 | |
| 1210 | #define init_wait(wait) \ |
| 1211 | do { \ |
| 1212 | (wait)->private = current; \ |
| 1213 | (wait)->func = autoremove_wake_function; \ |
| 1214 | INIT_LIST_HEAD(&(wait)->entry); \ |
| 1215 | (wait)->flags = 0; \ |
| 1216 | } while (0) |
| 1217 | |
| 1218 | typedef int (*task_call_f)(struct task_struct *p, void *arg); |
| 1219 | extern int task_call_func(struct task_struct *p, task_call_f func, void *arg); |
| 1220 | |
| 1221 | #endif /* _LINUX_WAIT_H */ |