Line data Source code
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 = { &(name).head, &(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 2531 : init_waitqueue_func_entry(struct wait_queue_entry *wq_entry, wait_queue_func_t func)
91 : {
92 2531 : wq_entry->flags = 0;
93 2531 : wq_entry->private = NULL;
94 2531 : 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 40245 : static inline int waitqueue_active(struct wait_queue_head *wq_head)
128 : {
129 34606 : 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 0 : static inline bool wq_has_single_sleeper(struct wait_queue_head *wq_head)
141 : {
142 0 : 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 7304 : 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 7304 : smp_mb();
163 7305 : 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 6405 : static inline void __add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
172 : {
173 6405 : struct list_head *head = &wq_head->head;
174 6405 : struct wait_queue_entry *wq;
175 :
176 6405 : list_for_each_entry(wq, &wq_head->head, entry) {
177 271 : if (!(wq->flags & WQ_FLAG_PRIORITY))
178 : break;
179 0 : head = &wq->entry;
180 : }
181 6405 : list_add(&wq_entry->entry, head);
182 6405 : }
183 :
184 : /*
185 : * Used for wake-one threads:
186 : */
187 : static inline void
188 1534 : __add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
189 : {
190 1534 : wq_entry->flags |= WQ_FLAG_EXCLUSIVE;
191 1534 : __add_wait_queue(wq_head, wq_entry);
192 1534 : }
193 :
194 959 : static inline void __add_wait_queue_entry_tail(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
195 : {
196 959 : list_add_tail(&wq_entry->entry, &wq_head->head);
197 959 : }
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 3070 : __remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
208 : {
209 3070 : list_del(&wq_entry->entry);
210 0 : }
211 :
212 : void __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 :
221 : #define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL)
222 : #define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL)
223 : #define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL)
224 : #define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL, 1)
225 : #define wake_up_all_locked(x) __wake_up_locked((x), TASK_NORMAL, 0)
226 :
227 : #define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
228 : #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
229 : #define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
230 : #define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE)
231 :
232 : /*
233 : * Wakeup macros to be used to report events to the targets.
234 : */
235 : #define poll_to_key(m) ((void *)(__force uintptr_t)(__poll_t)(m))
236 : #define key_to_poll(m) ((__force __poll_t)(uintptr_t)(void *)(m))
237 : #define wake_up_poll(x, m) \
238 : __wake_up(x, TASK_NORMAL, 1, poll_to_key(m))
239 : #define wake_up_locked_poll(x, m) \
240 : __wake_up_locked_key((x), TASK_NORMAL, poll_to_key(m))
241 : #define wake_up_interruptible_poll(x, m) \
242 : __wake_up(x, TASK_INTERRUPTIBLE, 1, poll_to_key(m))
243 : #define wake_up_interruptible_sync_poll(x, m) \
244 : __wake_up_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m))
245 : #define wake_up_interruptible_sync_poll_locked(x, m) \
246 : __wake_up_locked_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m))
247 :
248 : #define ___wait_cond_timeout(condition) \
249 : ({ \
250 : bool __cond = (condition); \
251 : if (__cond && !__ret) \
252 : __ret = 1; \
253 : __cond || !__ret; \
254 : })
255 :
256 : #define ___wait_is_interruptible(state) \
257 : (!__builtin_constant_p(state) || \
258 : state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE) \
259 :
260 : extern void init_wait_entry(struct wait_queue_entry *wq_entry, int flags);
261 :
262 : /*
263 : * The below macro ___wait_event() has an explicit shadow of the __ret
264 : * variable when used from the wait_event_*() macros.
265 : *
266 : * This is so that both can use the ___wait_cond_timeout() construct
267 : * to wrap the condition.
268 : *
269 : * The type inconsistency of the wait_event_*() __ret variable is also
270 : * on purpose; we use long where we can return timeout values and int
271 : * otherwise.
272 : */
273 :
274 : #define ___wait_event(wq_head, condition, state, exclusive, ret, cmd) \
275 : ({ \
276 : __label__ __out; \
277 : struct wait_queue_entry __wq_entry; \
278 : long __ret = ret; /* explicit shadow */ \
279 : \
280 : init_wait_entry(&__wq_entry, exclusive ? WQ_FLAG_EXCLUSIVE : 0); \
281 : for (;;) { \
282 : long __int = prepare_to_wait_event(&wq_head, &__wq_entry, state);\
283 : \
284 : if (condition) \
285 : break; \
286 : \
287 : if (___wait_is_interruptible(state) && __int) { \
288 : __ret = __int; \
289 : goto __out; \
290 : } \
291 : \
292 : cmd; \
293 : } \
294 : finish_wait(&wq_head, &__wq_entry); \
295 : __out: __ret; \
296 : })
297 :
298 : #define __wait_event(wq_head, condition) \
299 : (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
300 : schedule())
301 :
302 : /**
303 : * wait_event - sleep until a condition gets true
304 : * @wq_head: the waitqueue to wait on
305 : * @condition: a C expression for the event to wait for
306 : *
307 : * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
308 : * @condition evaluates to true. The @condition is checked each time
309 : * the waitqueue @wq_head is woken up.
310 : *
311 : * wake_up() has to be called after changing any variable that could
312 : * change the result of the wait condition.
313 : */
314 : #define wait_event(wq_head, condition) \
315 : do { \
316 : might_sleep(); \
317 : if (condition) \
318 : break; \
319 : __wait_event(wq_head, condition); \
320 : } while (0)
321 :
322 : #define __io_wait_event(wq_head, condition) \
323 : (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
324 : io_schedule())
325 :
326 : /*
327 : * io_wait_event() -- like wait_event() but with io_schedule()
328 : */
329 : #define io_wait_event(wq_head, condition) \
330 : do { \
331 : might_sleep(); \
332 : if (condition) \
333 : break; \
334 : __io_wait_event(wq_head, condition); \
335 : } while (0)
336 :
337 : #define __wait_event_freezable(wq_head, condition) \
338 : ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0, \
339 : freezable_schedule())
340 :
341 : /**
342 : * wait_event_freezable - sleep (or freeze) until a condition gets true
343 : * @wq_head: the waitqueue to wait on
344 : * @condition: a C expression for the event to wait for
345 : *
346 : * The process is put to sleep (TASK_INTERRUPTIBLE -- so as not to contribute
347 : * to system load) until the @condition evaluates to true. The
348 : * @condition is checked each time the waitqueue @wq_head is woken up.
349 : *
350 : * wake_up() has to be called after changing any variable that could
351 : * change the result of the wait condition.
352 : */
353 : #define wait_event_freezable(wq_head, condition) \
354 : ({ \
355 : int __ret = 0; \
356 : might_sleep(); \
357 : if (!(condition)) \
358 : __ret = __wait_event_freezable(wq_head, condition); \
359 : __ret; \
360 : })
361 :
362 : #define __wait_event_timeout(wq_head, condition, timeout) \
363 : ___wait_event(wq_head, ___wait_cond_timeout(condition), \
364 : TASK_UNINTERRUPTIBLE, 0, timeout, \
365 : __ret = schedule_timeout(__ret))
366 :
367 : /**
368 : * wait_event_timeout - sleep until a condition gets true or a timeout elapses
369 : * @wq_head: the waitqueue to wait on
370 : * @condition: a C expression for the event to wait for
371 : * @timeout: timeout, in jiffies
372 : *
373 : * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
374 : * @condition evaluates to true. The @condition is checked each time
375 : * the waitqueue @wq_head is woken up.
376 : *
377 : * wake_up() has to be called after changing any variable that could
378 : * change the result of the wait condition.
379 : *
380 : * Returns:
381 : * 0 if the @condition evaluated to %false after the @timeout elapsed,
382 : * 1 if the @condition evaluated to %true after the @timeout elapsed,
383 : * or the remaining jiffies (at least 1) if the @condition evaluated
384 : * to %true before the @timeout elapsed.
385 : */
386 : #define wait_event_timeout(wq_head, condition, timeout) \
387 : ({ \
388 : long __ret = timeout; \
389 : might_sleep(); \
390 : if (!___wait_cond_timeout(condition)) \
391 : __ret = __wait_event_timeout(wq_head, condition, timeout); \
392 : __ret; \
393 : })
394 :
395 : #define __wait_event_freezable_timeout(wq_head, condition, timeout) \
396 : ___wait_event(wq_head, ___wait_cond_timeout(condition), \
397 : TASK_INTERRUPTIBLE, 0, timeout, \
398 : __ret = freezable_schedule_timeout(__ret))
399 :
400 : /*
401 : * like wait_event_timeout() -- except it uses TASK_INTERRUPTIBLE to avoid
402 : * increasing load and is freezable.
403 : */
404 : #define wait_event_freezable_timeout(wq_head, condition, timeout) \
405 : ({ \
406 : long __ret = timeout; \
407 : might_sleep(); \
408 : if (!___wait_cond_timeout(condition)) \
409 : __ret = __wait_event_freezable_timeout(wq_head, condition, timeout); \
410 : __ret; \
411 : })
412 :
413 : #define __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2) \
414 : (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 1, 0, \
415 : cmd1; schedule(); cmd2)
416 : /*
417 : * Just like wait_event_cmd(), except it sets exclusive flag
418 : */
419 : #define wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2) \
420 : do { \
421 : if (condition) \
422 : break; \
423 : __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2); \
424 : } while (0)
425 :
426 : #define __wait_event_cmd(wq_head, condition, cmd1, cmd2) \
427 : (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
428 : cmd1; schedule(); cmd2)
429 :
430 : /**
431 : * wait_event_cmd - sleep until a condition gets true
432 : * @wq_head: the waitqueue to wait on
433 : * @condition: a C expression for the event to wait for
434 : * @cmd1: the command will be executed before sleep
435 : * @cmd2: the command will be executed after sleep
436 : *
437 : * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
438 : * @condition evaluates to true. The @condition is checked each time
439 : * the waitqueue @wq_head is woken up.
440 : *
441 : * wake_up() has to be called after changing any variable that could
442 : * change the result of the wait condition.
443 : */
444 : #define wait_event_cmd(wq_head, condition, cmd1, cmd2) \
445 : do { \
446 : if (condition) \
447 : break; \
448 : __wait_event_cmd(wq_head, condition, cmd1, cmd2); \
449 : } while (0)
450 :
451 : #define __wait_event_interruptible(wq_head, condition) \
452 : ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0, \
453 : schedule())
454 :
455 : /**
456 : * wait_event_interruptible - sleep until a condition gets true
457 : * @wq_head: the waitqueue to wait on
458 : * @condition: a C expression for the event to wait for
459 : *
460 : * The process is put to sleep (TASK_INTERRUPTIBLE) until the
461 : * @condition evaluates to true or a signal is received.
462 : * The @condition is checked each time the waitqueue @wq_head is woken up.
463 : *
464 : * wake_up() has to be called after changing any variable that could
465 : * change the result of the wait condition.
466 : *
467 : * The function will return -ERESTARTSYS if it was interrupted by a
468 : * signal and 0 if @condition evaluated to true.
469 : */
470 : #define wait_event_interruptible(wq_head, condition) \
471 : ({ \
472 : int __ret = 0; \
473 : might_sleep(); \
474 : if (!(condition)) \
475 : __ret = __wait_event_interruptible(wq_head, condition); \
476 : __ret; \
477 : })
478 :
479 : #define __wait_event_interruptible_timeout(wq_head, condition, timeout) \
480 : ___wait_event(wq_head, ___wait_cond_timeout(condition), \
481 : TASK_INTERRUPTIBLE, 0, timeout, \
482 : __ret = schedule_timeout(__ret))
483 :
484 : /**
485 : * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
486 : * @wq_head: the waitqueue to wait on
487 : * @condition: a C expression for the event to wait for
488 : * @timeout: timeout, in jiffies
489 : *
490 : * The process is put to sleep (TASK_INTERRUPTIBLE) until the
491 : * @condition evaluates to true or a signal is received.
492 : * The @condition is checked each time the waitqueue @wq_head is woken up.
493 : *
494 : * wake_up() has to be called after changing any variable that could
495 : * change the result of the wait condition.
496 : *
497 : * Returns:
498 : * 0 if the @condition evaluated to %false after the @timeout elapsed,
499 : * 1 if the @condition evaluated to %true after the @timeout elapsed,
500 : * the remaining jiffies (at least 1) if the @condition evaluated
501 : * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
502 : * interrupted by a signal.
503 : */
504 : #define wait_event_interruptible_timeout(wq_head, condition, timeout) \
505 : ({ \
506 : long __ret = timeout; \
507 : might_sleep(); \
508 : if (!___wait_cond_timeout(condition)) \
509 : __ret = __wait_event_interruptible_timeout(wq_head, \
510 : condition, timeout); \
511 : __ret; \
512 : })
513 :
514 : #define __wait_event_hrtimeout(wq_head, condition, timeout, state) \
515 : ({ \
516 : int __ret = 0; \
517 : struct hrtimer_sleeper __t; \
518 : \
519 : hrtimer_init_sleeper_on_stack(&__t, CLOCK_MONOTONIC, \
520 : HRTIMER_MODE_REL); \
521 : if ((timeout) != KTIME_MAX) \
522 : hrtimer_start_range_ns(&__t.timer, timeout, \
523 : current->timer_slack_ns, \
524 : HRTIMER_MODE_REL); \
525 : \
526 : __ret = ___wait_event(wq_head, condition, state, 0, 0, \
527 : if (!__t.task) { \
528 : __ret = -ETIME; \
529 : break; \
530 : } \
531 : schedule()); \
532 : \
533 : hrtimer_cancel(&__t.timer); \
534 : destroy_hrtimer_on_stack(&__t.timer); \
535 : __ret; \
536 : })
537 :
538 : /**
539 : * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses
540 : * @wq_head: the waitqueue to wait on
541 : * @condition: a C expression for the event to wait for
542 : * @timeout: timeout, as a ktime_t
543 : *
544 : * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
545 : * @condition evaluates to true or a signal is received.
546 : * The @condition is checked each time the waitqueue @wq_head is woken up.
547 : *
548 : * wake_up() has to be called after changing any variable that could
549 : * change the result of the wait condition.
550 : *
551 : * The function returns 0 if @condition became true, or -ETIME if the timeout
552 : * elapsed.
553 : */
554 : #define wait_event_hrtimeout(wq_head, condition, timeout) \
555 : ({ \
556 : int __ret = 0; \
557 : might_sleep(); \
558 : if (!(condition)) \
559 : __ret = __wait_event_hrtimeout(wq_head, condition, timeout, \
560 : TASK_UNINTERRUPTIBLE); \
561 : __ret; \
562 : })
563 :
564 : /**
565 : * wait_event_interruptible_hrtimeout - sleep until a condition gets true or a timeout elapses
566 : * @wq: the waitqueue to wait on
567 : * @condition: a C expression for the event to wait for
568 : * @timeout: timeout, as a ktime_t
569 : *
570 : * The process is put to sleep (TASK_INTERRUPTIBLE) until the
571 : * @condition evaluates to true or a signal is received.
572 : * The @condition is checked each time the waitqueue @wq is woken up.
573 : *
574 : * wake_up() has to be called after changing any variable that could
575 : * change the result of the wait condition.
576 : *
577 : * The function returns 0 if @condition became true, -ERESTARTSYS if it was
578 : * interrupted by a signal, or -ETIME if the timeout elapsed.
579 : */
580 : #define wait_event_interruptible_hrtimeout(wq, condition, timeout) \
581 : ({ \
582 : long __ret = 0; \
583 : might_sleep(); \
584 : if (!(condition)) \
585 : __ret = __wait_event_hrtimeout(wq, condition, timeout, \
586 : TASK_INTERRUPTIBLE); \
587 : __ret; \
588 : })
589 :
590 : #define __wait_event_interruptible_exclusive(wq, condition) \
591 : ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \
592 : schedule())
593 :
594 : #define wait_event_interruptible_exclusive(wq, condition) \
595 : ({ \
596 : int __ret = 0; \
597 : might_sleep(); \
598 : if (!(condition)) \
599 : __ret = __wait_event_interruptible_exclusive(wq, condition); \
600 : __ret; \
601 : })
602 :
603 : #define __wait_event_killable_exclusive(wq, condition) \
604 : ___wait_event(wq, condition, TASK_KILLABLE, 1, 0, \
605 : schedule())
606 :
607 : #define wait_event_killable_exclusive(wq, condition) \
608 : ({ \
609 : int __ret = 0; \
610 : might_sleep(); \
611 : if (!(condition)) \
612 : __ret = __wait_event_killable_exclusive(wq, condition); \
613 : __ret; \
614 : })
615 :
616 :
617 : #define __wait_event_freezable_exclusive(wq, condition) \
618 : ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \
619 : freezable_schedule())
620 :
621 : #define wait_event_freezable_exclusive(wq, condition) \
622 : ({ \
623 : int __ret = 0; \
624 : might_sleep(); \
625 : if (!(condition)) \
626 : __ret = __wait_event_freezable_exclusive(wq, condition); \
627 : __ret; \
628 : })
629 :
630 : /**
631 : * wait_event_idle - wait for a condition without contributing to system load
632 : * @wq_head: the waitqueue to wait on
633 : * @condition: a C expression for the event to wait for
634 : *
635 : * The process is put to sleep (TASK_IDLE) until the
636 : * @condition evaluates to true.
637 : * The @condition is checked each time the waitqueue @wq_head is woken up.
638 : *
639 : * wake_up() has to be called after changing any variable that could
640 : * change the result of the wait condition.
641 : *
642 : */
643 : #define wait_event_idle(wq_head, condition) \
644 : do { \
645 : might_sleep(); \
646 : if (!(condition)) \
647 : ___wait_event(wq_head, condition, TASK_IDLE, 0, 0, schedule()); \
648 : } while (0)
649 :
650 : /**
651 : * wait_event_idle_exclusive - wait for a condition with contributing to system load
652 : * @wq_head: the waitqueue to wait on
653 : * @condition: a C expression for the event to wait for
654 : *
655 : * The process is put to sleep (TASK_IDLE) until the
656 : * @condition evaluates to true.
657 : * The @condition is checked each time the waitqueue @wq_head is woken up.
658 : *
659 : * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
660 : * set thus if other processes wait on the same list, when this
661 : * process is woken further processes are not considered.
662 : *
663 : * wake_up() has to be called after changing any variable that could
664 : * change the result of the wait condition.
665 : *
666 : */
667 : #define wait_event_idle_exclusive(wq_head, condition) \
668 : do { \
669 : might_sleep(); \
670 : if (!(condition)) \
671 : ___wait_event(wq_head, condition, TASK_IDLE, 1, 0, schedule()); \
672 : } while (0)
673 :
674 : #define __wait_event_idle_timeout(wq_head, condition, timeout) \
675 : ___wait_event(wq_head, ___wait_cond_timeout(condition), \
676 : TASK_IDLE, 0, timeout, \
677 : __ret = schedule_timeout(__ret))
678 :
679 : /**
680 : * wait_event_idle_timeout - sleep without load until a condition becomes true or a timeout elapses
681 : * @wq_head: the waitqueue to wait on
682 : * @condition: a C expression for the event to wait for
683 : * @timeout: timeout, in jiffies
684 : *
685 : * The process is put to sleep (TASK_IDLE) until the
686 : * @condition evaluates to true. The @condition is checked each time
687 : * the waitqueue @wq_head is woken up.
688 : *
689 : * wake_up() has to be called after changing any variable that could
690 : * change the result of the wait condition.
691 : *
692 : * Returns:
693 : * 0 if the @condition evaluated to %false after the @timeout elapsed,
694 : * 1 if the @condition evaluated to %true after the @timeout elapsed,
695 : * or the remaining jiffies (at least 1) if the @condition evaluated
696 : * to %true before the @timeout elapsed.
697 : */
698 : #define wait_event_idle_timeout(wq_head, condition, timeout) \
699 : ({ \
700 : long __ret = timeout; \
701 : might_sleep(); \
702 : if (!___wait_cond_timeout(condition)) \
703 : __ret = __wait_event_idle_timeout(wq_head, condition, timeout); \
704 : __ret; \
705 : })
706 :
707 : #define __wait_event_idle_exclusive_timeout(wq_head, condition, timeout) \
708 : ___wait_event(wq_head, ___wait_cond_timeout(condition), \
709 : TASK_IDLE, 1, timeout, \
710 : __ret = schedule_timeout(__ret))
711 :
712 : /**
713 : * wait_event_idle_exclusive_timeout - sleep without load until a condition becomes true or a timeout elapses
714 : * @wq_head: the waitqueue to wait on
715 : * @condition: a C expression for the event to wait for
716 : * @timeout: timeout, in jiffies
717 : *
718 : * The process is put to sleep (TASK_IDLE) until the
719 : * @condition evaluates to true. The @condition is checked each time
720 : * the waitqueue @wq_head is woken up.
721 : *
722 : * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
723 : * set thus if other processes wait on the same list, when this
724 : * process is woken further processes are not considered.
725 : *
726 : * wake_up() has to be called after changing any variable that could
727 : * change the result of the wait condition.
728 : *
729 : * Returns:
730 : * 0 if the @condition evaluated to %false after the @timeout elapsed,
731 : * 1 if the @condition evaluated to %true after the @timeout elapsed,
732 : * or the remaining jiffies (at least 1) if the @condition evaluated
733 : * to %true before the @timeout elapsed.
734 : */
735 : #define wait_event_idle_exclusive_timeout(wq_head, condition, timeout) \
736 : ({ \
737 : long __ret = timeout; \
738 : might_sleep(); \
739 : if (!___wait_cond_timeout(condition)) \
740 : __ret = __wait_event_idle_exclusive_timeout(wq_head, condition, timeout);\
741 : __ret; \
742 : })
743 :
744 : extern int do_wait_intr(wait_queue_head_t *, wait_queue_entry_t *);
745 : extern int do_wait_intr_irq(wait_queue_head_t *, wait_queue_entry_t *);
746 :
747 : #define __wait_event_interruptible_locked(wq, condition, exclusive, fn) \
748 : ({ \
749 : int __ret; \
750 : DEFINE_WAIT(__wait); \
751 : if (exclusive) \
752 : __wait.flags |= WQ_FLAG_EXCLUSIVE; \
753 : do { \
754 : __ret = fn(&(wq), &__wait); \
755 : if (__ret) \
756 : break; \
757 : } while (!(condition)); \
758 : __remove_wait_queue(&(wq), &__wait); \
759 : __set_current_state(TASK_RUNNING); \
760 : __ret; \
761 : })
762 :
763 :
764 : /**
765 : * wait_event_interruptible_locked - sleep until a condition gets true
766 : * @wq: the waitqueue to wait on
767 : * @condition: a C expression for the event to wait for
768 : *
769 : * The process is put to sleep (TASK_INTERRUPTIBLE) until the
770 : * @condition evaluates to true or a signal is received.
771 : * The @condition is checked each time the waitqueue @wq is woken up.
772 : *
773 : * It must be called with wq.lock being held. This spinlock is
774 : * unlocked while sleeping but @condition testing is done while lock
775 : * is held and when this macro exits the lock is held.
776 : *
777 : * The lock is locked/unlocked using spin_lock()/spin_unlock()
778 : * functions which must match the way they are locked/unlocked outside
779 : * of this macro.
780 : *
781 : * wake_up_locked() has to be called after changing any variable that could
782 : * change the result of the wait condition.
783 : *
784 : * The function will return -ERESTARTSYS if it was interrupted by a
785 : * signal and 0 if @condition evaluated to true.
786 : */
787 : #define wait_event_interruptible_locked(wq, condition) \
788 : ((condition) \
789 : ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr))
790 :
791 : /**
792 : * wait_event_interruptible_locked_irq - 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_irq()/spin_unlock_irq()
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_irq(wq, condition) \
815 : ((condition) \
816 : ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr_irq))
817 :
818 : /**
819 : * wait_event_interruptible_exclusive_locked - sleep exclusively 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()/spin_unlock()
832 : * functions which must match the way they are locked/unlocked outside
833 : * of this macro.
834 : *
835 : * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
836 : * set thus when other process waits process on the list if this
837 : * process is awaken further processes are not considered.
838 : *
839 : * wake_up_locked() has to be called after changing any variable that could
840 : * change the result of the wait condition.
841 : *
842 : * The function will return -ERESTARTSYS if it was interrupted by a
843 : * signal and 0 if @condition evaluated to true.
844 : */
845 : #define wait_event_interruptible_exclusive_locked(wq, condition) \
846 : ((condition) \
847 : ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr))
848 :
849 : /**
850 : * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true
851 : * @wq: the waitqueue to wait on
852 : * @condition: a C expression for the event to wait for
853 : *
854 : * The process is put to sleep (TASK_INTERRUPTIBLE) until the
855 : * @condition evaluates to true or a signal is received.
856 : * The @condition is checked each time the waitqueue @wq is woken up.
857 : *
858 : * It must be called with wq.lock being held. This spinlock is
859 : * unlocked while sleeping but @condition testing is done while lock
860 : * is held and when this macro exits the lock is held.
861 : *
862 : * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
863 : * functions which must match the way they are locked/unlocked outside
864 : * of this macro.
865 : *
866 : * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
867 : * set thus when other process waits process on the list if this
868 : * process is awaken further processes are not considered.
869 : *
870 : * wake_up_locked() has to be called after changing any variable that could
871 : * change the result of the wait condition.
872 : *
873 : * The function will return -ERESTARTSYS if it was interrupted by a
874 : * signal and 0 if @condition evaluated to true.
875 : */
876 : #define wait_event_interruptible_exclusive_locked_irq(wq, condition) \
877 : ((condition) \
878 : ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr_irq))
879 :
880 :
881 : #define __wait_event_killable(wq, condition) \
882 : ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule())
883 :
884 : /**
885 : * wait_event_killable - sleep until a condition gets true
886 : * @wq_head: the waitqueue to wait on
887 : * @condition: a C expression for the event to wait for
888 : *
889 : * The process is put to sleep (TASK_KILLABLE) until the
890 : * @condition evaluates to true or a signal is received.
891 : * The @condition is checked each time the waitqueue @wq_head is woken up.
892 : *
893 : * wake_up() has to be called after changing any variable that could
894 : * change the result of the wait condition.
895 : *
896 : * The function will return -ERESTARTSYS if it was interrupted by a
897 : * signal and 0 if @condition evaluated to true.
898 : */
899 : #define wait_event_killable(wq_head, condition) \
900 : ({ \
901 : int __ret = 0; \
902 : might_sleep(); \
903 : if (!(condition)) \
904 : __ret = __wait_event_killable(wq_head, condition); \
905 : __ret; \
906 : })
907 :
908 : #define __wait_event_killable_timeout(wq_head, condition, timeout) \
909 : ___wait_event(wq_head, ___wait_cond_timeout(condition), \
910 : TASK_KILLABLE, 0, timeout, \
911 : __ret = schedule_timeout(__ret))
912 :
913 : /**
914 : * wait_event_killable_timeout - sleep until a condition gets true or a timeout elapses
915 : * @wq_head: the waitqueue to wait on
916 : * @condition: a C expression for the event to wait for
917 : * @timeout: timeout, in jiffies
918 : *
919 : * The process is put to sleep (TASK_KILLABLE) until the
920 : * @condition evaluates to true or a kill signal is received.
921 : * The @condition is checked each time the waitqueue @wq_head is woken up.
922 : *
923 : * wake_up() has to be called after changing any variable that could
924 : * change the result of the wait condition.
925 : *
926 : * Returns:
927 : * 0 if the @condition evaluated to %false after the @timeout elapsed,
928 : * 1 if the @condition evaluated to %true after the @timeout elapsed,
929 : * the remaining jiffies (at least 1) if the @condition evaluated
930 : * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
931 : * interrupted by a kill signal.
932 : *
933 : * Only kill signals interrupt this process.
934 : */
935 : #define wait_event_killable_timeout(wq_head, condition, timeout) \
936 : ({ \
937 : long __ret = timeout; \
938 : might_sleep(); \
939 : if (!___wait_cond_timeout(condition)) \
940 : __ret = __wait_event_killable_timeout(wq_head, \
941 : condition, timeout); \
942 : __ret; \
943 : })
944 :
945 :
946 : #define __wait_event_lock_irq(wq_head, condition, lock, cmd) \
947 : (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
948 : spin_unlock_irq(&lock); \
949 : cmd; \
950 : schedule(); \
951 : spin_lock_irq(&lock))
952 :
953 : /**
954 : * wait_event_lock_irq_cmd - sleep until a condition gets true. The
955 : * condition is checked under the lock. This
956 : * is expected to be called with the lock
957 : * taken.
958 : * @wq_head: the waitqueue to wait on
959 : * @condition: a C expression for the event to wait for
960 : * @lock: a locked spinlock_t, which will be released before cmd
961 : * and schedule() and reacquired afterwards.
962 : * @cmd: a command which is invoked outside the critical section before
963 : * sleep
964 : *
965 : * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
966 : * @condition evaluates to true. The @condition is checked each time
967 : * the waitqueue @wq_head is woken up.
968 : *
969 : * wake_up() has to be called after changing any variable that could
970 : * change the result of the wait condition.
971 : *
972 : * This is supposed to be called while holding the lock. The lock is
973 : * dropped before invoking the cmd and going to sleep and is reacquired
974 : * afterwards.
975 : */
976 : #define wait_event_lock_irq_cmd(wq_head, condition, lock, cmd) \
977 : do { \
978 : if (condition) \
979 : break; \
980 : __wait_event_lock_irq(wq_head, condition, lock, cmd); \
981 : } while (0)
982 :
983 : /**
984 : * wait_event_lock_irq - sleep until a condition gets true. The
985 : * condition is checked under the lock. This
986 : * is expected to be called with the lock
987 : * taken.
988 : * @wq_head: the waitqueue to wait on
989 : * @condition: a C expression for the event to wait for
990 : * @lock: a locked spinlock_t, which will be released before schedule()
991 : * and reacquired afterwards.
992 : *
993 : * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
994 : * @condition evaluates to true. The @condition is checked each time
995 : * the waitqueue @wq_head is woken up.
996 : *
997 : * wake_up() has to be called after changing any variable that could
998 : * change the result of the wait condition.
999 : *
1000 : * This is supposed to be called while holding the lock. The lock is
1001 : * dropped before going to sleep and is reacquired afterwards.
1002 : */
1003 : #define wait_event_lock_irq(wq_head, condition, lock) \
1004 : do { \
1005 : if (condition) \
1006 : break; \
1007 : __wait_event_lock_irq(wq_head, condition, lock, ); \
1008 : } while (0)
1009 :
1010 :
1011 : #define __wait_event_interruptible_lock_irq(wq_head, condition, lock, cmd) \
1012 : ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0, \
1013 : spin_unlock_irq(&lock); \
1014 : cmd; \
1015 : schedule(); \
1016 : spin_lock_irq(&lock))
1017 :
1018 : /**
1019 : * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true.
1020 : * The condition is checked under the lock. This is expected to
1021 : * be called with the lock taken.
1022 : * @wq_head: the waitqueue to wait on
1023 : * @condition: a C expression for the event to wait for
1024 : * @lock: a locked spinlock_t, which will be released before cmd and
1025 : * schedule() and reacquired afterwards.
1026 : * @cmd: a command which is invoked outside the critical section before
1027 : * sleep
1028 : *
1029 : * The process is put to sleep (TASK_INTERRUPTIBLE) until the
1030 : * @condition evaluates to true or a signal is received. The @condition is
1031 : * checked each time the waitqueue @wq_head is woken up.
1032 : *
1033 : * wake_up() has to be called after changing any variable that could
1034 : * change the result of the wait condition.
1035 : *
1036 : * This is supposed to be called while holding the lock. The lock is
1037 : * dropped before invoking the cmd and going to sleep and is reacquired
1038 : * afterwards.
1039 : *
1040 : * The macro will return -ERESTARTSYS if it was interrupted by a signal
1041 : * and 0 if @condition evaluated to true.
1042 : */
1043 : #define wait_event_interruptible_lock_irq_cmd(wq_head, condition, lock, cmd) \
1044 : ({ \
1045 : int __ret = 0; \
1046 : if (!(condition)) \
1047 : __ret = __wait_event_interruptible_lock_irq(wq_head, \
1048 : condition, lock, cmd); \
1049 : __ret; \
1050 : })
1051 :
1052 : /**
1053 : * wait_event_interruptible_lock_irq - sleep until a condition gets true.
1054 : * The condition is checked under the lock. This is expected
1055 : * to be called with the lock taken.
1056 : * @wq_head: the waitqueue to wait on
1057 : * @condition: a C expression for the event to wait for
1058 : * @lock: a locked spinlock_t, which will be released before schedule()
1059 : * and reacquired afterwards.
1060 : *
1061 : * The process is put to sleep (TASK_INTERRUPTIBLE) until the
1062 : * @condition evaluates to true or signal is received. The @condition is
1063 : * checked each time the waitqueue @wq_head is woken up.
1064 : *
1065 : * wake_up() has to be called after changing any variable that could
1066 : * change the result of the wait condition.
1067 : *
1068 : * This is supposed to be called while holding the lock. The lock is
1069 : * dropped before going to sleep and is reacquired afterwards.
1070 : *
1071 : * The macro will return -ERESTARTSYS if it was interrupted by a signal
1072 : * and 0 if @condition evaluated to true.
1073 : */
1074 : #define wait_event_interruptible_lock_irq(wq_head, condition, lock) \
1075 : ({ \
1076 : int __ret = 0; \
1077 : if (!(condition)) \
1078 : __ret = __wait_event_interruptible_lock_irq(wq_head, \
1079 : condition, lock,); \
1080 : __ret; \
1081 : })
1082 :
1083 : #define __wait_event_lock_irq_timeout(wq_head, condition, lock, timeout, state) \
1084 : ___wait_event(wq_head, ___wait_cond_timeout(condition), \
1085 : state, 0, timeout, \
1086 : spin_unlock_irq(&lock); \
1087 : __ret = schedule_timeout(__ret); \
1088 : spin_lock_irq(&lock));
1089 :
1090 : /**
1091 : * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets
1092 : * true or a timeout elapses. The condition is checked under
1093 : * the lock. This is expected to be called with the lock taken.
1094 : * @wq_head: the waitqueue to wait on
1095 : * @condition: a C expression for the event to wait for
1096 : * @lock: a locked spinlock_t, which will be released before schedule()
1097 : * and reacquired afterwards.
1098 : * @timeout: timeout, in jiffies
1099 : *
1100 : * The process is put to sleep (TASK_INTERRUPTIBLE) until the
1101 : * @condition evaluates to true or signal is received. The @condition is
1102 : * checked each time the waitqueue @wq_head is woken up.
1103 : *
1104 : * wake_up() has to be called after changing any variable that could
1105 : * change the result of the wait condition.
1106 : *
1107 : * This is supposed to be called while holding the lock. The lock is
1108 : * dropped before going to sleep and is reacquired afterwards.
1109 : *
1110 : * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
1111 : * was interrupted by a signal, and the remaining jiffies otherwise
1112 : * if the condition evaluated to true before the timeout elapsed.
1113 : */
1114 : #define wait_event_interruptible_lock_irq_timeout(wq_head, condition, lock, \
1115 : timeout) \
1116 : ({ \
1117 : long __ret = timeout; \
1118 : if (!___wait_cond_timeout(condition)) \
1119 : __ret = __wait_event_lock_irq_timeout( \
1120 : wq_head, condition, lock, timeout, \
1121 : TASK_INTERRUPTIBLE); \
1122 : __ret; \
1123 : })
1124 :
1125 : #define wait_event_lock_irq_timeout(wq_head, condition, lock, timeout) \
1126 : ({ \
1127 : long __ret = timeout; \
1128 : if (!___wait_cond_timeout(condition)) \
1129 : __ret = __wait_event_lock_irq_timeout( \
1130 : wq_head, condition, lock, timeout, \
1131 : TASK_UNINTERRUPTIBLE); \
1132 : __ret; \
1133 : })
1134 :
1135 : /*
1136 : * Waitqueues which are removed from the waitqueue_head at wakeup time
1137 : */
1138 : void prepare_to_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
1139 : void prepare_to_wait_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
1140 : long prepare_to_wait_event(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
1141 : void finish_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
1142 : long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout);
1143 : int woken_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);
1144 : int autoremove_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);
1145 :
1146 : #define DEFINE_WAIT_FUNC(name, function) \
1147 : struct wait_queue_entry name = { \
1148 : .private = current, \
1149 : .func = function, \
1150 : .entry = LIST_HEAD_INIT((name).entry), \
1151 : }
1152 :
1153 : #define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function)
1154 :
1155 : #define init_wait(wait) \
1156 : do { \
1157 : (wait)->private = current; \
1158 : (wait)->func = autoremove_wake_function; \
1159 : INIT_LIST_HEAD(&(wait)->entry); \
1160 : (wait)->flags = 0; \
1161 : } while (0)
1162 :
1163 : bool try_invoke_on_locked_down_task(struct task_struct *p, bool (*func)(struct task_struct *t, void *arg), void *arg);
1164 :
1165 : #endif /* _LINUX_WAIT_H */
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