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 = 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 0 : wq_entry->flags = 0;
85 0 : wq_entry->private = p;
86 0 : 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 0 : wq_entry->flags = 0;
93 0 : wq_entry->private = NULL;
94 0 : 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 : {
129 876 : 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 : */
162 267 : smp_mb();
163 267 : 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 3 : struct list_head *head = &wq_head->head;
174 : struct wait_queue_entry *wq;
175 :
176 3 : list_for_each_entry(wq, &wq_head->head, entry) {
177 0 : if (!(wq->flags & WQ_FLAG_PRIORITY))
178 : break;
179 0 : head = &wq->entry;
180 : }
181 6 : 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 0 : wq_entry->flags |= WQ_FLAG_EXCLUSIVE;
191 0 : __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 0 : 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 0 : 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 : */
270 160 : if (waitqueue_active(wq_head))
271 0 : __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 */
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