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
init_waitqueue_entry(struct wait_queue_entry * wq_entry,struct task_struct * p)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
init_waitqueue_func_entry(struct wait_queue_entry * wq_entry,wait_queue_func_t func)90 init_waitqueue_func_entry(struct wait_queue_entry *wq_entry, wait_queue_func_t func)
91 {
92 wq_entry->flags = 0;
93 wq_entry->private = NULL;
94 wq_entry->func = func;
95 }
96
97 /**
98 * waitqueue_active -- locklessly test for waiters on the queue
99 * @wq_head: the waitqueue to test for waiters
100 *
101 * returns true if the wait list is not empty
102 *
103 * NOTE: this function is lockless and requires care, incorrect usage _will_
104 * lead to sporadic and non-obvious failure.
105 *
106 * Use either while holding wait_queue_head::lock or when used for wakeups
107 * with an extra smp_mb() like::
108 *
109 * CPU0 - waker CPU1 - waiter
110 *
111 * for (;;) {
112 * @cond = true; prepare_to_wait(&wq_head, &wait, state);
113 * smp_mb(); // smp_mb() from set_current_state()
114 * if (waitqueue_active(wq_head)) if (@cond)
115 * wake_up(wq_head); break;
116 * schedule();
117 * }
118 * finish_wait(&wq_head, &wait);
119 *
120 * Because without the explicit smp_mb() it's possible for the
121 * waitqueue_active() load to get hoisted over the @cond store such that we'll
122 * observe an empty wait list while the waiter might not observe @cond.
123 *
124 * Also note that this 'optimization' trades a spin_lock() for an smp_mb(),
125 * which (when the lock is uncontended) are of roughly equal cost.
126 */
waitqueue_active(struct wait_queue_head * wq_head)127 static inline int waitqueue_active(struct wait_queue_head *wq_head)
128 {
129 return !list_empty(&wq_head->head);
130 }
131
132 /**
133 * wq_has_single_sleeper - check if there is only one sleeper
134 * @wq_head: wait queue head
135 *
136 * Returns true of wq_head has only one sleeper on the list.
137 *
138 * Please refer to the comment for waitqueue_active.
139 */
wq_has_single_sleeper(struct wait_queue_head * wq_head)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 */
wq_has_sleeper(struct wait_queue_head * wq_head)153 static inline bool wq_has_sleeper(struct wait_queue_head *wq_head)
154 {
155 /*
156 * We need to be sure we are in sync with the
157 * add_wait_queue modifications to the wait queue.
158 *
159 * This memory barrier should be paired with one on the
160 * waiting side.
161 */
162 smp_mb();
163 return waitqueue_active(wq_head);
164 }
165
166 extern void add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
167 extern void add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
168 extern void add_wait_queue_priority(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
169 extern void remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
170
__add_wait_queue(struct wait_queue_head * wq_head,struct wait_queue_entry * wq_entry)171 static inline void __add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
172 {
173 struct list_head *head = &wq_head->head;
174 struct wait_queue_entry *wq;
175
176 list_for_each_entry(wq, &wq_head->head, entry) {
177 if (!(wq->flags & WQ_FLAG_PRIORITY))
178 break;
179 head = &wq->entry;
180 }
181 list_add(&wq_entry->entry, head);
182 }
183
184 /*
185 * Used for wake-one threads:
186 */
187 static inline void
__add_wait_queue_exclusive(struct wait_queue_head * wq_head,struct wait_queue_entry * wq_entry)188 __add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
189 {
190 wq_entry->flags |= WQ_FLAG_EXCLUSIVE;
191 __add_wait_queue(wq_head, wq_entry);
192 }
193
__add_wait_queue_entry_tail(struct wait_queue_head * wq_head,struct wait_queue_entry * wq_entry)194 static inline void __add_wait_queue_entry_tail(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
195 {
196 list_add_tail(&wq_entry->entry, &wq_head->head);
197 }
198
199 static inline void
__add_wait_queue_entry_tail_exclusive(struct wait_queue_head * wq_head,struct wait_queue_entry * wq_entry)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
__remove_wait_queue(struct wait_queue_head * wq_head,struct wait_queue_entry * wq_entry)207 __remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
208 {
209 list_del(&wq_entry->entry);
210 }
211
212 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 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 */
wake_up_pollfree(struct wait_queue_head * wq_head)261 static inline void wake_up_pollfree(struct wait_queue_head *wq_head)
262 {
263 /*
264 * For performance reasons, we don't always take the queue lock here.
265 * Therefore, we might race with someone removing the last entry from
266 * the queue, and proceed while they still hold the queue lock.
267 * However, rcu_read_lock() is required to be held in such cases, so we
268 * can safely proceed with an RCU-delayed free.
269 */
270 if (waitqueue_active(wq_head))
271 __wake_up_pollfree(wq_head);
272 }
273
274 #define ___wait_cond_timeout(condition) \
275 ({ \
276 bool __cond = (condition); \
277 if (__cond && !__ret) \
278 __ret = 1; \
279 __cond || !__ret; \
280 })
281
282 #define ___wait_is_interruptible(state) \
283 (!__builtin_constant_p(state) || \
284 (state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
285
286 extern void init_wait_entry(struct wait_queue_entry *wq_entry, int flags);
287
288 /*
289 * The below macro ___wait_event() has an explicit shadow of the __ret
290 * variable when used from the wait_event_*() macros.
291 *
292 * This is so that both can use the ___wait_cond_timeout() construct
293 * to wrap the condition.
294 *
295 * The type inconsistency of the wait_event_*() __ret variable is also
296 * on purpose; we use long where we can return timeout values and int
297 * otherwise.
298 */
299
300 #define ___wait_event(wq_head, condition, state, exclusive, ret, cmd) \
301 ({ \
302 __label__ __out; \
303 struct wait_queue_entry __wq_entry; \
304 long __ret = ret; /* explicit shadow */ \
305 \
306 init_wait_entry(&__wq_entry, exclusive ? WQ_FLAG_EXCLUSIVE : 0); \
307 for (;;) { \
308 long __int = prepare_to_wait_event(&wq_head, &__wq_entry, state);\
309 \
310 if (condition) \
311 break; \
312 \
313 if (___wait_is_interruptible(state) && __int) { \
314 __ret = __int; \
315 goto __out; \
316 } \
317 \
318 cmd; \
319 } \
320 finish_wait(&wq_head, &__wq_entry); \
321 __out: __ret; \
322 })
323
324 #define __wait_event(wq_head, condition) \
325 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
326 schedule())
327
328 /**
329 * wait_event - sleep until a condition gets true
330 * @wq_head: the waitqueue to wait on
331 * @condition: a C expression for the event to wait for
332 *
333 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
334 * @condition evaluates to true. The @condition is checked each time
335 * the waitqueue @wq_head is woken up.
336 *
337 * wake_up() has to be called after changing any variable that could
338 * change the result of the wait condition.
339 */
340 #define wait_event(wq_head, condition) \
341 do { \
342 might_sleep(); \
343 if (condition) \
344 break; \
345 __wait_event(wq_head, condition); \
346 } while (0)
347
348 #define __io_wait_event(wq_head, condition) \
349 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
350 io_schedule())
351
352 /*
353 * io_wait_event() -- like wait_event() but with io_schedule()
354 */
355 #define io_wait_event(wq_head, condition) \
356 do { \
357 might_sleep(); \
358 if (condition) \
359 break; \
360 __io_wait_event(wq_head, condition); \
361 } while (0)
362
363 #define __wait_event_freezable(wq_head, condition) \
364 ___wait_event(wq_head, condition, (TASK_INTERRUPTIBLE|TASK_FREEZABLE), \
365 0, 0, schedule())
366
367 /**
368 * wait_event_freezable - sleep (or freeze) until a condition gets true
369 * @wq_head: the waitqueue to wait on
370 * @condition: a C expression for the event to wait for
371 *
372 * The process is put to sleep (TASK_INTERRUPTIBLE -- so as not to contribute
373 * to system load) until the @condition evaluates to true. The
374 * @condition is checked each time the waitqueue @wq_head is woken up.
375 *
376 * wake_up() has to be called after changing any variable that could
377 * change the result of the wait condition.
378 */
379 #define wait_event_freezable(wq_head, condition) \
380 ({ \
381 int __ret = 0; \
382 might_sleep(); \
383 if (!(condition)) \
384 __ret = __wait_event_freezable(wq_head, condition); \
385 __ret; \
386 })
387
388 #define __wait_event_timeout(wq_head, condition, timeout) \
389 ___wait_event(wq_head, ___wait_cond_timeout(condition), \
390 TASK_UNINTERRUPTIBLE, 0, timeout, \
391 __ret = schedule_timeout(__ret))
392
393 /**
394 * wait_event_timeout - sleep until a condition gets true or a timeout elapses
395 * @wq_head: the waitqueue to wait on
396 * @condition: a C expression for the event to wait for
397 * @timeout: timeout, in jiffies
398 *
399 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
400 * @condition evaluates to true. The @condition is checked each time
401 * the waitqueue @wq_head is woken up.
402 *
403 * wake_up() has to be called after changing any variable that could
404 * change the result of the wait condition.
405 *
406 * Returns:
407 * 0 if the @condition evaluated to %false after the @timeout elapsed,
408 * 1 if the @condition evaluated to %true after the @timeout elapsed,
409 * or the remaining jiffies (at least 1) if the @condition evaluated
410 * to %true before the @timeout elapsed.
411 */
412 #define wait_event_timeout(wq_head, condition, timeout) \
413 ({ \
414 long __ret = timeout; \
415 might_sleep(); \
416 if (!___wait_cond_timeout(condition)) \
417 __ret = __wait_event_timeout(wq_head, condition, timeout); \
418 __ret; \
419 })
420
421 #define __wait_event_freezable_timeout(wq_head, condition, timeout) \
422 ___wait_event(wq_head, ___wait_cond_timeout(condition), \
423 (TASK_INTERRUPTIBLE|TASK_FREEZABLE), 0, timeout, \
424 __ret = schedule_timeout(__ret))
425
426 /*
427 * like wait_event_timeout() -- except it uses TASK_INTERRUPTIBLE to avoid
428 * increasing load and is freezable.
429 */
430 #define wait_event_freezable_timeout(wq_head, condition, timeout) \
431 ({ \
432 long __ret = timeout; \
433 might_sleep(); \
434 if (!___wait_cond_timeout(condition)) \
435 __ret = __wait_event_freezable_timeout(wq_head, condition, timeout); \
436 __ret; \
437 })
438
439 #define __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2) \
440 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 1, 0, \
441 cmd1; schedule(); cmd2)
442 /*
443 * Just like wait_event_cmd(), except it sets exclusive flag
444 */
445 #define wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2) \
446 do { \
447 if (condition) \
448 break; \
449 __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2); \
450 } while (0)
451
452 #define __wait_event_cmd(wq_head, condition, cmd1, cmd2) \
453 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
454 cmd1; schedule(); cmd2)
455
456 /**
457 * wait_event_cmd - sleep until a condition gets true
458 * @wq_head: the waitqueue to wait on
459 * @condition: a C expression for the event to wait for
460 * @cmd1: the command will be executed before sleep
461 * @cmd2: the command will be executed after sleep
462 *
463 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
464 * @condition evaluates to true. The @condition is checked each time
465 * the waitqueue @wq_head is woken up.
466 *
467 * wake_up() has to be called after changing any variable that could
468 * change the result of the wait condition.
469 */
470 #define wait_event_cmd(wq_head, condition, cmd1, cmd2) \
471 do { \
472 if (condition) \
473 break; \
474 __wait_event_cmd(wq_head, condition, cmd1, cmd2); \
475 } while (0)
476
477 #define __wait_event_interruptible(wq_head, condition) \
478 ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0, \
479 schedule())
480
481 /**
482 * wait_event_interruptible - sleep until a condition gets true
483 * @wq_head: the waitqueue to wait on
484 * @condition: a C expression for the event to wait for
485 *
486 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
487 * @condition evaluates to true or a signal is received.
488 * The @condition is checked each time the waitqueue @wq_head is woken up.
489 *
490 * wake_up() has to be called after changing any variable that could
491 * change the result of the wait condition.
492 *
493 * The function will return -ERESTARTSYS if it was interrupted by a
494 * signal and 0 if @condition evaluated to true.
495 */
496 #define wait_event_interruptible(wq_head, condition) \
497 ({ \
498 int __ret = 0; \
499 might_sleep(); \
500 if (!(condition)) \
501 __ret = __wait_event_interruptible(wq_head, condition); \
502 __ret; \
503 })
504
505 #define __wait_event_interruptible_timeout(wq_head, condition, timeout) \
506 ___wait_event(wq_head, ___wait_cond_timeout(condition), \
507 TASK_INTERRUPTIBLE, 0, timeout, \
508 __ret = schedule_timeout(__ret))
509
510 /**
511 * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
512 * @wq_head: the waitqueue to wait on
513 * @condition: a C expression for the event to wait for
514 * @timeout: timeout, in jiffies
515 *
516 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
517 * @condition evaluates to true or a signal is received.
518 * The @condition is checked each time the waitqueue @wq_head is woken up.
519 *
520 * wake_up() has to be called after changing any variable that could
521 * change the result of the wait condition.
522 *
523 * Returns:
524 * 0 if the @condition evaluated to %false after the @timeout elapsed,
525 * 1 if the @condition evaluated to %true after the @timeout elapsed,
526 * the remaining jiffies (at least 1) if the @condition evaluated
527 * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
528 * interrupted by a signal.
529 */
530 #define wait_event_interruptible_timeout(wq_head, condition, timeout) \
531 ({ \
532 long __ret = timeout; \
533 might_sleep(); \
534 if (!___wait_cond_timeout(condition)) \
535 __ret = __wait_event_interruptible_timeout(wq_head, \
536 condition, timeout); \
537 __ret; \
538 })
539
540 #define __wait_event_hrtimeout(wq_head, condition, timeout, state) \
541 ({ \
542 int __ret = 0; \
543 struct hrtimer_sleeper __t; \
544 \
545 hrtimer_init_sleeper_on_stack(&__t, CLOCK_MONOTONIC, \
546 HRTIMER_MODE_REL); \
547 if ((timeout) != KTIME_MAX) { \
548 hrtimer_set_expires_range_ns(&__t.timer, timeout, \
549 current->timer_slack_ns); \
550 hrtimer_sleeper_start_expires(&__t, HRTIMER_MODE_REL); \
551 } \
552 \
553 __ret = ___wait_event(wq_head, condition, state, 0, 0, \
554 if (!__t.task) { \
555 __ret = -ETIME; \
556 break; \
557 } \
558 schedule()); \
559 \
560 hrtimer_cancel(&__t.timer); \
561 destroy_hrtimer_on_stack(&__t.timer); \
562 __ret; \
563 })
564
565 /**
566 * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses
567 * @wq_head: the waitqueue to wait on
568 * @condition: a C expression for the event to wait for
569 * @timeout: timeout, as a ktime_t
570 *
571 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
572 * @condition evaluates to true or a signal is received.
573 * The @condition is checked each time the waitqueue @wq_head is woken up.
574 *
575 * wake_up() has to be called after changing any variable that could
576 * change the result of the wait condition.
577 *
578 * The function returns 0 if @condition became true, or -ETIME if the timeout
579 * elapsed.
580 */
581 #define wait_event_hrtimeout(wq_head, condition, timeout) \
582 ({ \
583 int __ret = 0; \
584 might_sleep(); \
585 if (!(condition)) \
586 __ret = __wait_event_hrtimeout(wq_head, condition, timeout, \
587 TASK_UNINTERRUPTIBLE); \
588 __ret; \
589 })
590
591 /**
592 * wait_event_interruptible_hrtimeout - sleep until a condition gets true or a timeout elapses
593 * @wq: the waitqueue to wait on
594 * @condition: a C expression for the event to wait for
595 * @timeout: timeout, as a ktime_t
596 *
597 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
598 * @condition evaluates to true or a signal is received.
599 * The @condition is checked each time the waitqueue @wq is woken up.
600 *
601 * wake_up() has to be called after changing any variable that could
602 * change the result of the wait condition.
603 *
604 * The function returns 0 if @condition became true, -ERESTARTSYS if it was
605 * interrupted by a signal, or -ETIME if the timeout elapsed.
606 */
607 #define wait_event_interruptible_hrtimeout(wq, condition, timeout) \
608 ({ \
609 long __ret = 0; \
610 might_sleep(); \
611 if (!(condition)) \
612 __ret = __wait_event_hrtimeout(wq, condition, timeout, \
613 TASK_INTERRUPTIBLE); \
614 __ret; \
615 })
616
617 #define __wait_event_interruptible_exclusive(wq, condition) \
618 ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \
619 schedule())
620
621 #define wait_event_interruptible_exclusive(wq, condition) \
622 ({ \
623 int __ret = 0; \
624 might_sleep(); \
625 if (!(condition)) \
626 __ret = __wait_event_interruptible_exclusive(wq, condition); \
627 __ret; \
628 })
629
630 #define __wait_event_killable_exclusive(wq, condition) \
631 ___wait_event(wq, condition, TASK_KILLABLE, 1, 0, \
632 schedule())
633
634 #define wait_event_killable_exclusive(wq, condition) \
635 ({ \
636 int __ret = 0; \
637 might_sleep(); \
638 if (!(condition)) \
639 __ret = __wait_event_killable_exclusive(wq, condition); \
640 __ret; \
641 })
642
643
644 #define __wait_event_freezable_exclusive(wq, condition) \
645 ___wait_event(wq, condition, (TASK_INTERRUPTIBLE|TASK_FREEZABLE), 1, 0,\
646 schedule())
647
648 #define wait_event_freezable_exclusive(wq, condition) \
649 ({ \
650 int __ret = 0; \
651 might_sleep(); \
652 if (!(condition)) \
653 __ret = __wait_event_freezable_exclusive(wq, condition); \
654 __ret; \
655 })
656
657 /**
658 * wait_event_idle - wait for a condition without contributing to system load
659 * @wq_head: the waitqueue to wait on
660 * @condition: a C expression for the event to wait for
661 *
662 * The process is put to sleep (TASK_IDLE) until the
663 * @condition evaluates to true.
664 * The @condition is checked each time the waitqueue @wq_head is woken up.
665 *
666 * wake_up() has to be called after changing any variable that could
667 * change the result of the wait condition.
668 *
669 */
670 #define wait_event_idle(wq_head, condition) \
671 do { \
672 might_sleep(); \
673 if (!(condition)) \
674 ___wait_event(wq_head, condition, TASK_IDLE, 0, 0, schedule()); \
675 } while (0)
676
677 /**
678 * wait_event_idle_exclusive - wait for a condition with contributing to system load
679 * @wq_head: the waitqueue to wait on
680 * @condition: a C expression for the event to wait for
681 *
682 * The process is put to sleep (TASK_IDLE) until the
683 * @condition evaluates to true.
684 * The @condition is checked each time the waitqueue @wq_head is woken up.
685 *
686 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
687 * set thus if other processes wait on the same list, when this
688 * process is woken further processes are not considered.
689 *
690 * wake_up() has to be called after changing any variable that could
691 * change the result of the wait condition.
692 *
693 */
694 #define wait_event_idle_exclusive(wq_head, condition) \
695 do { \
696 might_sleep(); \
697 if (!(condition)) \
698 ___wait_event(wq_head, condition, TASK_IDLE, 1, 0, schedule()); \
699 } while (0)
700
701 #define __wait_event_idle_timeout(wq_head, condition, timeout) \
702 ___wait_event(wq_head, ___wait_cond_timeout(condition), \
703 TASK_IDLE, 0, timeout, \
704 __ret = schedule_timeout(__ret))
705
706 /**
707 * wait_event_idle_timeout - sleep without load until a condition becomes true or a timeout elapses
708 * @wq_head: the waitqueue to wait on
709 * @condition: a C expression for the event to wait for
710 * @timeout: timeout, in jiffies
711 *
712 * The process is put to sleep (TASK_IDLE) until the
713 * @condition evaluates to true. The @condition is checked each time
714 * the waitqueue @wq_head is woken up.
715 *
716 * wake_up() has to be called after changing any variable that could
717 * change the result of the wait condition.
718 *
719 * Returns:
720 * 0 if the @condition evaluated to %false after the @timeout elapsed,
721 * 1 if the @condition evaluated to %true after the @timeout elapsed,
722 * or the remaining jiffies (at least 1) if the @condition evaluated
723 * to %true before the @timeout elapsed.
724 */
725 #define wait_event_idle_timeout(wq_head, condition, timeout) \
726 ({ \
727 long __ret = timeout; \
728 might_sleep(); \
729 if (!___wait_cond_timeout(condition)) \
730 __ret = __wait_event_idle_timeout(wq_head, condition, timeout); \
731 __ret; \
732 })
733
734 #define __wait_event_idle_exclusive_timeout(wq_head, condition, timeout) \
735 ___wait_event(wq_head, ___wait_cond_timeout(condition), \
736 TASK_IDLE, 1, timeout, \
737 __ret = schedule_timeout(__ret))
738
739 /**
740 * wait_event_idle_exclusive_timeout - sleep without load until a condition becomes true or a timeout elapses
741 * @wq_head: the waitqueue to wait on
742 * @condition: a C expression for the event to wait for
743 * @timeout: timeout, in jiffies
744 *
745 * The process is put to sleep (TASK_IDLE) until the
746 * @condition evaluates to true. The @condition is checked each time
747 * the waitqueue @wq_head is woken up.
748 *
749 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
750 * set thus if other processes wait on the same list, when this
751 * process is woken further processes are not considered.
752 *
753 * wake_up() has to be called after changing any variable that could
754 * change the result of the wait condition.
755 *
756 * Returns:
757 * 0 if the @condition evaluated to %false after the @timeout elapsed,
758 * 1 if the @condition evaluated to %true after the @timeout elapsed,
759 * or the remaining jiffies (at least 1) if the @condition evaluated
760 * to %true before the @timeout elapsed.
761 */
762 #define wait_event_idle_exclusive_timeout(wq_head, condition, timeout) \
763 ({ \
764 long __ret = timeout; \
765 might_sleep(); \
766 if (!___wait_cond_timeout(condition)) \
767 __ret = __wait_event_idle_exclusive_timeout(wq_head, condition, timeout);\
768 __ret; \
769 })
770
771 extern int do_wait_intr(wait_queue_head_t *, wait_queue_entry_t *);
772 extern int do_wait_intr_irq(wait_queue_head_t *, wait_queue_entry_t *);
773
774 #define __wait_event_interruptible_locked(wq, condition, exclusive, fn) \
775 ({ \
776 int __ret; \
777 DEFINE_WAIT(__wait); \
778 if (exclusive) \
779 __wait.flags |= WQ_FLAG_EXCLUSIVE; \
780 do { \
781 __ret = fn(&(wq), &__wait); \
782 if (__ret) \
783 break; \
784 } while (!(condition)); \
785 __remove_wait_queue(&(wq), &__wait); \
786 __set_current_state(TASK_RUNNING); \
787 __ret; \
788 })
789
790
791 /**
792 * wait_event_interruptible_locked - sleep until a condition gets true
793 * @wq: the waitqueue to wait on
794 * @condition: a C expression for the event to wait for
795 *
796 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
797 * @condition evaluates to true or a signal is received.
798 * The @condition is checked each time the waitqueue @wq is woken up.
799 *
800 * It must be called with wq.lock being held. This spinlock is
801 * unlocked while sleeping but @condition testing is done while lock
802 * is held and when this macro exits the lock is held.
803 *
804 * The lock is locked/unlocked using spin_lock()/spin_unlock()
805 * functions which must match the way they are locked/unlocked outside
806 * of this macro.
807 *
808 * wake_up_locked() has to be called after changing any variable that could
809 * change the result of the wait condition.
810 *
811 * The function will return -ERESTARTSYS if it was interrupted by a
812 * signal and 0 if @condition evaluated to true.
813 */
814 #define wait_event_interruptible_locked(wq, condition) \
815 ((condition) \
816 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr))
817
818 /**
819 * wait_event_interruptible_locked_irq - sleep until a condition gets true
820 * @wq: the waitqueue to wait on
821 * @condition: a C expression for the event to wait for
822 *
823 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
824 * @condition evaluates to true or a signal is received.
825 * The @condition is checked each time the waitqueue @wq is woken up.
826 *
827 * It must be called with wq.lock being held. This spinlock is
828 * unlocked while sleeping but @condition testing is done while lock
829 * is held and when this macro exits the lock is held.
830 *
831 * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
832 * functions which must match the way they are locked/unlocked outside
833 * of this macro.
834 *
835 * wake_up_locked() has to be called after changing any variable that could
836 * change the result of the wait condition.
837 *
838 * The function will return -ERESTARTSYS if it was interrupted by a
839 * signal and 0 if @condition evaluated to true.
840 */
841 #define wait_event_interruptible_locked_irq(wq, condition) \
842 ((condition) \
843 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr_irq))
844
845 /**
846 * wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true
847 * @wq: the waitqueue to wait on
848 * @condition: a C expression for the event to wait for
849 *
850 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
851 * @condition evaluates to true or a signal is received.
852 * The @condition is checked each time the waitqueue @wq is woken up.
853 *
854 * It must be called with wq.lock being held. This spinlock is
855 * unlocked while sleeping but @condition testing is done while lock
856 * is held and when this macro exits the lock is held.
857 *
858 * The lock is locked/unlocked using spin_lock()/spin_unlock()
859 * functions which must match the way they are locked/unlocked outside
860 * of this macro.
861 *
862 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
863 * set thus when other process waits process on the list if this
864 * process is awaken further processes are not considered.
865 *
866 * wake_up_locked() has to be called after changing any variable that could
867 * change the result of the wait condition.
868 *
869 * The function will return -ERESTARTSYS if it was interrupted by a
870 * signal and 0 if @condition evaluated to true.
871 */
872 #define wait_event_interruptible_exclusive_locked(wq, condition) \
873 ((condition) \
874 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr))
875
876 /**
877 * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true
878 * @wq: the waitqueue to wait on
879 * @condition: a C expression for the event to wait for
880 *
881 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
882 * @condition evaluates to true or a signal is received.
883 * The @condition is checked each time the waitqueue @wq is woken up.
884 *
885 * It must be called with wq.lock being held. This spinlock is
886 * unlocked while sleeping but @condition testing is done while lock
887 * is held and when this macro exits the lock is held.
888 *
889 * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
890 * functions which must match the way they are locked/unlocked outside
891 * of this macro.
892 *
893 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
894 * set thus when other process waits process on the list if this
895 * process is awaken further processes are not considered.
896 *
897 * wake_up_locked() has to be called after changing any variable that could
898 * change the result of the wait condition.
899 *
900 * The function will return -ERESTARTSYS if it was interrupted by a
901 * signal and 0 if @condition evaluated to true.
902 */
903 #define wait_event_interruptible_exclusive_locked_irq(wq, condition) \
904 ((condition) \
905 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr_irq))
906
907
908 #define __wait_event_killable(wq, condition) \
909 ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule())
910
911 /**
912 * wait_event_killable - sleep until a condition gets true
913 * @wq_head: the waitqueue to wait on
914 * @condition: a C expression for the event to wait for
915 *
916 * The process is put to sleep (TASK_KILLABLE) until the
917 * @condition evaluates to true or a signal is received.
918 * The @condition is checked each time the waitqueue @wq_head is woken up.
919 *
920 * wake_up() has to be called after changing any variable that could
921 * change the result of the wait condition.
922 *
923 * The function will return -ERESTARTSYS if it was interrupted by a
924 * signal and 0 if @condition evaluated to true.
925 */
926 #define wait_event_killable(wq_head, condition) \
927 ({ \
928 int __ret = 0; \
929 might_sleep(); \
930 if (!(condition)) \
931 __ret = __wait_event_killable(wq_head, condition); \
932 __ret; \
933 })
934
935 #define __wait_event_state(wq, condition, state) \
936 ___wait_event(wq, condition, state, 0, 0, schedule())
937
938 /**
939 * wait_event_state - sleep until a condition gets true
940 * @wq_head: the waitqueue to wait on
941 * @condition: a C expression for the event to wait for
942 * @state: state to sleep in
943 *
944 * The process is put to sleep (@state) until the @condition evaluates to true
945 * or a signal is received (when allowed by @state). The @condition is checked
946 * each time the waitqueue @wq_head is woken up.
947 *
948 * wake_up() has to be called after changing any variable that could
949 * change the result of the wait condition.
950 *
951 * The function will return -ERESTARTSYS if it was interrupted by a signal
952 * (when allowed by @state) and 0 if @condition evaluated to true.
953 */
954 #define wait_event_state(wq_head, condition, state) \
955 ({ \
956 int __ret = 0; \
957 might_sleep(); \
958 if (!(condition)) \
959 __ret = __wait_event_state(wq_head, condition, state); \
960 __ret; \
961 })
962
963 #define __wait_event_killable_timeout(wq_head, condition, timeout) \
964 ___wait_event(wq_head, ___wait_cond_timeout(condition), \
965 TASK_KILLABLE, 0, timeout, \
966 __ret = schedule_timeout(__ret))
967
968 /**
969 * wait_event_killable_timeout - sleep until a condition gets true or a timeout elapses
970 * @wq_head: the waitqueue to wait on
971 * @condition: a C expression for the event to wait for
972 * @timeout: timeout, in jiffies
973 *
974 * The process is put to sleep (TASK_KILLABLE) until the
975 * @condition evaluates to true or a kill signal is received.
976 * The @condition is checked each time the waitqueue @wq_head is woken up.
977 *
978 * wake_up() has to be called after changing any variable that could
979 * change the result of the wait condition.
980 *
981 * Returns:
982 * 0 if the @condition evaluated to %false after the @timeout elapsed,
983 * 1 if the @condition evaluated to %true after the @timeout elapsed,
984 * the remaining jiffies (at least 1) if the @condition evaluated
985 * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
986 * interrupted by a kill signal.
987 *
988 * Only kill signals interrupt this process.
989 */
990 #define wait_event_killable_timeout(wq_head, condition, timeout) \
991 ({ \
992 long __ret = timeout; \
993 might_sleep(); \
994 if (!___wait_cond_timeout(condition)) \
995 __ret = __wait_event_killable_timeout(wq_head, \
996 condition, timeout); \
997 __ret; \
998 })
999
1000
1001 #define __wait_event_lock_irq(wq_head, condition, lock, cmd) \
1002 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
1003 spin_unlock_irq(&lock); \
1004 cmd; \
1005 schedule(); \
1006 spin_lock_irq(&lock))
1007
1008 /**
1009 * wait_event_lock_irq_cmd - sleep until a condition gets true. The
1010 * condition is checked under the lock. This
1011 * is expected to be called with the lock
1012 * taken.
1013 * @wq_head: the waitqueue to wait on
1014 * @condition: a C expression for the event to wait for
1015 * @lock: a locked spinlock_t, which will be released before cmd
1016 * and schedule() and reacquired afterwards.
1017 * @cmd: a command which is invoked outside the critical section before
1018 * sleep
1019 *
1020 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
1021 * @condition evaluates to true. The @condition is checked each time
1022 * the waitqueue @wq_head is woken up.
1023 *
1024 * wake_up() has to be called after changing any variable that could
1025 * change the result of the wait condition.
1026 *
1027 * This is supposed to be called while holding the lock. The lock is
1028 * dropped before invoking the cmd and going to sleep and is reacquired
1029 * afterwards.
1030 */
1031 #define wait_event_lock_irq_cmd(wq_head, condition, lock, cmd) \
1032 do { \
1033 if (condition) \
1034 break; \
1035 __wait_event_lock_irq(wq_head, condition, lock, cmd); \
1036 } while (0)
1037
1038 /**
1039 * wait_event_lock_irq - sleep until a condition gets true. The
1040 * condition is checked under the lock. This
1041 * is expected to be called with the lock
1042 * taken.
1043 * @wq_head: the waitqueue to wait on
1044 * @condition: a C expression for the event to wait for
1045 * @lock: a locked spinlock_t, which will be released before schedule()
1046 * and reacquired afterwards.
1047 *
1048 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
1049 * @condition evaluates to true. The @condition is checked each time
1050 * the waitqueue @wq_head is woken up.
1051 *
1052 * wake_up() has to be called after changing any variable that could
1053 * change the result of the wait condition.
1054 *
1055 * This is supposed to be called while holding the lock. The lock is
1056 * dropped before going to sleep and is reacquired afterwards.
1057 */
1058 #define wait_event_lock_irq(wq_head, condition, lock) \
1059 do { \
1060 if (condition) \
1061 break; \
1062 __wait_event_lock_irq(wq_head, condition, lock, ); \
1063 } while (0)
1064
1065
1066 #define __wait_event_interruptible_lock_irq(wq_head, condition, lock, cmd) \
1067 ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0, \
1068 spin_unlock_irq(&lock); \
1069 cmd; \
1070 schedule(); \
1071 spin_lock_irq(&lock))
1072
1073 /**
1074 * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true.
1075 * The condition is checked under the lock. This is expected to
1076 * be called with the lock taken.
1077 * @wq_head: the waitqueue to wait on
1078 * @condition: a C expression for the event to wait for
1079 * @lock: a locked spinlock_t, which will be released before cmd and
1080 * schedule() and reacquired afterwards.
1081 * @cmd: a command which is invoked outside the critical section before
1082 * sleep
1083 *
1084 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
1085 * @condition evaluates to true or a signal is received. The @condition is
1086 * checked each time the waitqueue @wq_head is woken up.
1087 *
1088 * wake_up() has to be called after changing any variable that could
1089 * change the result of the wait condition.
1090 *
1091 * This is supposed to be called while holding the lock. The lock is
1092 * dropped before invoking the cmd and going to sleep and is reacquired
1093 * afterwards.
1094 *
1095 * The macro will return -ERESTARTSYS if it was interrupted by a signal
1096 * and 0 if @condition evaluated to true.
1097 */
1098 #define wait_event_interruptible_lock_irq_cmd(wq_head, condition, lock, cmd) \
1099 ({ \
1100 int __ret = 0; \
1101 if (!(condition)) \
1102 __ret = __wait_event_interruptible_lock_irq(wq_head, \
1103 condition, lock, cmd); \
1104 __ret; \
1105 })
1106
1107 /**
1108 * wait_event_interruptible_lock_irq - sleep until a condition gets true.
1109 * The condition is checked under the lock. This is expected
1110 * to be called with the lock taken.
1111 * @wq_head: the waitqueue to wait on
1112 * @condition: a C expression for the event to wait for
1113 * @lock: a locked spinlock_t, which will be released before schedule()
1114 * and reacquired afterwards.
1115 *
1116 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
1117 * @condition evaluates to true or signal is received. The @condition is
1118 * checked each time the waitqueue @wq_head is woken up.
1119 *
1120 * wake_up() has to be called after changing any variable that could
1121 * change the result of the wait condition.
1122 *
1123 * This is supposed to be called while holding the lock. The lock is
1124 * dropped before going to sleep and is reacquired afterwards.
1125 *
1126 * The macro will return -ERESTARTSYS if it was interrupted by a signal
1127 * and 0 if @condition evaluated to true.
1128 */
1129 #define wait_event_interruptible_lock_irq(wq_head, condition, lock) \
1130 ({ \
1131 int __ret = 0; \
1132 if (!(condition)) \
1133 __ret = __wait_event_interruptible_lock_irq(wq_head, \
1134 condition, lock,); \
1135 __ret; \
1136 })
1137
1138 #define __wait_event_lock_irq_timeout(wq_head, condition, lock, timeout, state) \
1139 ___wait_event(wq_head, ___wait_cond_timeout(condition), \
1140 state, 0, timeout, \
1141 spin_unlock_irq(&lock); \
1142 __ret = schedule_timeout(__ret); \
1143 spin_lock_irq(&lock));
1144
1145 /**
1146 * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets
1147 * true or a timeout elapses. The condition is checked under
1148 * the lock. This is expected to be called with the lock taken.
1149 * @wq_head: the waitqueue to wait on
1150 * @condition: a C expression for the event to wait for
1151 * @lock: a locked spinlock_t, which will be released before schedule()
1152 * and reacquired afterwards.
1153 * @timeout: timeout, in jiffies
1154 *
1155 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
1156 * @condition evaluates to true or signal is received. The @condition is
1157 * checked each time the waitqueue @wq_head is woken up.
1158 *
1159 * wake_up() has to be called after changing any variable that could
1160 * change the result of the wait condition.
1161 *
1162 * This is supposed to be called while holding the lock. The lock is
1163 * dropped before going to sleep and is reacquired afterwards.
1164 *
1165 * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
1166 * was interrupted by a signal, and the remaining jiffies otherwise
1167 * if the condition evaluated to true before the timeout elapsed.
1168 */
1169 #define wait_event_interruptible_lock_irq_timeout(wq_head, condition, lock, \
1170 timeout) \
1171 ({ \
1172 long __ret = timeout; \
1173 if (!___wait_cond_timeout(condition)) \
1174 __ret = __wait_event_lock_irq_timeout( \
1175 wq_head, condition, lock, timeout, \
1176 TASK_INTERRUPTIBLE); \
1177 __ret; \
1178 })
1179
1180 #define wait_event_lock_irq_timeout(wq_head, condition, lock, timeout) \
1181 ({ \
1182 long __ret = timeout; \
1183 if (!___wait_cond_timeout(condition)) \
1184 __ret = __wait_event_lock_irq_timeout( \
1185 wq_head, condition, lock, timeout, \
1186 TASK_UNINTERRUPTIBLE); \
1187 __ret; \
1188 })
1189
1190 /*
1191 * Waitqueues which are removed from the waitqueue_head at wakeup time
1192 */
1193 void prepare_to_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
1194 bool prepare_to_wait_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
1195 long prepare_to_wait_event(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
1196 void finish_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
1197 long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout);
1198 int woken_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);
1199 int autoremove_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);
1200
1201 #define DEFINE_WAIT_FUNC(name, function) \
1202 struct wait_queue_entry name = { \
1203 .private = current, \
1204 .func = function, \
1205 .entry = LIST_HEAD_INIT((name).entry), \
1206 }
1207
1208 #define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function)
1209
1210 #define init_wait(wait) \
1211 do { \
1212 (wait)->private = current; \
1213 (wait)->func = autoremove_wake_function; \
1214 INIT_LIST_HEAD(&(wait)->entry); \
1215 (wait)->flags = 0; \
1216 } while (0)
1217
1218 typedef int (*task_call_f)(struct task_struct *p, void *arg);
1219 extern int task_call_func(struct task_struct *p, task_call_f func, void *arg);
1220
1221 #endif /* _LINUX_WAIT_H */
1222