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
221 #define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL)
222 #define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL)
223 #define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL)
224 #define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL, 1)
225 #define wake_up_all_locked(x) __wake_up_locked((x), TASK_NORMAL, 0)
226
227 #define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
228 #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
229 #define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
230 #define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE)
231
232 /*
233 * Wakeup macros to be used to report events to the targets.
234 */
235 #define poll_to_key(m) ((void *)(__force uintptr_t)(__poll_t)(m))
236 #define key_to_poll(m) ((__force __poll_t)(uintptr_t)(void *)(m))
237 #define wake_up_poll(x, m) \
238 __wake_up(x, TASK_NORMAL, 1, poll_to_key(m))
239 #define wake_up_locked_poll(x, m) \
240 __wake_up_locked_key((x), TASK_NORMAL, poll_to_key(m))
241 #define wake_up_interruptible_poll(x, m) \
242 __wake_up(x, TASK_INTERRUPTIBLE, 1, poll_to_key(m))
243 #define wake_up_interruptible_sync_poll(x, m) \
244 __wake_up_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m))
245 #define wake_up_interruptible_sync_poll_locked(x, m) \
246 __wake_up_locked_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m))
247
248 #define ___wait_cond_timeout(condition) \
249 ({ \
250 bool __cond = (condition); \
251 if (__cond && !__ret) \
252 __ret = 1; \
253 __cond || !__ret; \
254 })
255
256 #define ___wait_is_interruptible(state) \
257 (!__builtin_constant_p(state) || \
258 state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE) \
259
260 extern void init_wait_entry(struct wait_queue_entry *wq_entry, int flags);
261
262 /*
263 * The below macro ___wait_event() has an explicit shadow of the __ret
264 * variable when used from the wait_event_*() macros.
265 *
266 * This is so that both can use the ___wait_cond_timeout() construct
267 * to wrap the condition.
268 *
269 * The type inconsistency of the wait_event_*() __ret variable is also
270 * on purpose; we use long where we can return timeout values and int
271 * otherwise.
272 */
273
274 #define ___wait_event(wq_head, condition, state, exclusive, ret, cmd) \
275 ({ \
276 __label__ __out; \
277 struct wait_queue_entry __wq_entry; \
278 long __ret = ret; /* explicit shadow */ \
279 \
280 init_wait_entry(&__wq_entry, exclusive ? WQ_FLAG_EXCLUSIVE : 0); \
281 for (;;) { \
282 long __int = prepare_to_wait_event(&wq_head, &__wq_entry, state);\
283 \
284 if (condition) \
285 break; \
286 \
287 if (___wait_is_interruptible(state) && __int) { \
288 __ret = __int; \
289 goto __out; \
290 } \
291 \
292 cmd; \
293 } \
294 finish_wait(&wq_head, &__wq_entry); \
295 __out: __ret; \
296 })
297
298 #define __wait_event(wq_head, condition) \
299 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
300 schedule())
301
302 /**
303 * wait_event - sleep until a condition gets true
304 * @wq_head: the waitqueue to wait on
305 * @condition: a C expression for the event to wait for
306 *
307 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
308 * @condition evaluates to true. The @condition is checked each time
309 * the waitqueue @wq_head is woken up.
310 *
311 * wake_up() has to be called after changing any variable that could
312 * change the result of the wait condition.
313 */
314 #define wait_event(wq_head, condition) \
315 do { \
316 might_sleep(); \
317 if (condition) \
318 break; \
319 __wait_event(wq_head, condition); \
320 } while (0)
321
322 #define __io_wait_event(wq_head, condition) \
323 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
324 io_schedule())
325
326 /*
327 * io_wait_event() -- like wait_event() but with io_schedule()
328 */
329 #define io_wait_event(wq_head, condition) \
330 do { \
331 might_sleep(); \
332 if (condition) \
333 break; \
334 __io_wait_event(wq_head, condition); \
335 } while (0)
336
337 #define __wait_event_freezable(wq_head, condition) \
338 ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0, \
339 freezable_schedule())
340
341 /**
342 * wait_event_freezable - sleep (or freeze) until a condition gets true
343 * @wq_head: the waitqueue to wait on
344 * @condition: a C expression for the event to wait for
345 *
346 * The process is put to sleep (TASK_INTERRUPTIBLE -- so as not to contribute
347 * to system load) until the @condition evaluates to true. The
348 * @condition is checked each time the waitqueue @wq_head is woken up.
349 *
350 * wake_up() has to be called after changing any variable that could
351 * change the result of the wait condition.
352 */
353 #define wait_event_freezable(wq_head, condition) \
354 ({ \
355 int __ret = 0; \
356 might_sleep(); \
357 if (!(condition)) \
358 __ret = __wait_event_freezable(wq_head, condition); \
359 __ret; \
360 })
361
362 #define __wait_event_timeout(wq_head, condition, timeout) \
363 ___wait_event(wq_head, ___wait_cond_timeout(condition), \
364 TASK_UNINTERRUPTIBLE, 0, timeout, \
365 __ret = schedule_timeout(__ret))
366
367 /**
368 * wait_event_timeout - sleep until a condition gets true or a timeout elapses
369 * @wq_head: the waitqueue to wait on
370 * @condition: a C expression for the event to wait for
371 * @timeout: timeout, in jiffies
372 *
373 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
374 * @condition evaluates to true. The @condition is checked each time
375 * the waitqueue @wq_head is woken up.
376 *
377 * wake_up() has to be called after changing any variable that could
378 * change the result of the wait condition.
379 *
380 * Returns:
381 * 0 if the @condition evaluated to %false after the @timeout elapsed,
382 * 1 if the @condition evaluated to %true after the @timeout elapsed,
383 * or the remaining jiffies (at least 1) if the @condition evaluated
384 * to %true before the @timeout elapsed.
385 */
386 #define wait_event_timeout(wq_head, condition, timeout) \
387 ({ \
388 long __ret = timeout; \
389 might_sleep(); \
390 if (!___wait_cond_timeout(condition)) \
391 __ret = __wait_event_timeout(wq_head, condition, timeout); \
392 __ret; \
393 })
394
395 #define __wait_event_freezable_timeout(wq_head, condition, timeout) \
396 ___wait_event(wq_head, ___wait_cond_timeout(condition), \
397 TASK_INTERRUPTIBLE, 0, timeout, \
398 __ret = freezable_schedule_timeout(__ret))
399
400 /*
401 * like wait_event_timeout() -- except it uses TASK_INTERRUPTIBLE to avoid
402 * increasing load and is freezable.
403 */
404 #define wait_event_freezable_timeout(wq_head, condition, timeout) \
405 ({ \
406 long __ret = timeout; \
407 might_sleep(); \
408 if (!___wait_cond_timeout(condition)) \
409 __ret = __wait_event_freezable_timeout(wq_head, condition, timeout); \
410 __ret; \
411 })
412
413 #define __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2) \
414 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 1, 0, \
415 cmd1; schedule(); cmd2)
416 /*
417 * Just like wait_event_cmd(), except it sets exclusive flag
418 */
419 #define wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2) \
420 do { \
421 if (condition) \
422 break; \
423 __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2); \
424 } while (0)
425
426 #define __wait_event_cmd(wq_head, condition, cmd1, cmd2) \
427 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
428 cmd1; schedule(); cmd2)
429
430 /**
431 * wait_event_cmd - sleep until a condition gets true
432 * @wq_head: the waitqueue to wait on
433 * @condition: a C expression for the event to wait for
434 * @cmd1: the command will be executed before sleep
435 * @cmd2: the command will be executed after sleep
436 *
437 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
438 * @condition evaluates to true. The @condition is checked each time
439 * the waitqueue @wq_head is woken up.
440 *
441 * wake_up() has to be called after changing any variable that could
442 * change the result of the wait condition.
443 */
444 #define wait_event_cmd(wq_head, condition, cmd1, cmd2) \
445 do { \
446 if (condition) \
447 break; \
448 __wait_event_cmd(wq_head, condition, cmd1, cmd2); \
449 } while (0)
450
451 #define __wait_event_interruptible(wq_head, condition) \
452 ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0, \
453 schedule())
454
455 /**
456 * wait_event_interruptible - sleep until a condition gets true
457 * @wq_head: the waitqueue to wait on
458 * @condition: a C expression for the event to wait for
459 *
460 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
461 * @condition evaluates to true or a signal is received.
462 * The @condition is checked each time the waitqueue @wq_head is woken up.
463 *
464 * wake_up() has to be called after changing any variable that could
465 * change the result of the wait condition.
466 *
467 * The function will return -ERESTARTSYS if it was interrupted by a
468 * signal and 0 if @condition evaluated to true.
469 */
470 #define wait_event_interruptible(wq_head, condition) \
471 ({ \
472 int __ret = 0; \
473 might_sleep(); \
474 if (!(condition)) \
475 __ret = __wait_event_interruptible(wq_head, condition); \
476 __ret; \
477 })
478
479 #define __wait_event_interruptible_timeout(wq_head, condition, timeout) \
480 ___wait_event(wq_head, ___wait_cond_timeout(condition), \
481 TASK_INTERRUPTIBLE, 0, timeout, \
482 __ret = schedule_timeout(__ret))
483
484 /**
485 * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
486 * @wq_head: the waitqueue to wait on
487 * @condition: a C expression for the event to wait for
488 * @timeout: timeout, in jiffies
489 *
490 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
491 * @condition evaluates to true or a signal is received.
492 * The @condition is checked each time the waitqueue @wq_head is woken up.
493 *
494 * wake_up() has to be called after changing any variable that could
495 * change the result of the wait condition.
496 *
497 * Returns:
498 * 0 if the @condition evaluated to %false after the @timeout elapsed,
499 * 1 if the @condition evaluated to %true after the @timeout elapsed,
500 * the remaining jiffies (at least 1) if the @condition evaluated
501 * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
502 * interrupted by a signal.
503 */
504 #define wait_event_interruptible_timeout(wq_head, condition, timeout) \
505 ({ \
506 long __ret = timeout; \
507 might_sleep(); \
508 if (!___wait_cond_timeout(condition)) \
509 __ret = __wait_event_interruptible_timeout(wq_head, \
510 condition, timeout); \
511 __ret; \
512 })
513
514 #define __wait_event_hrtimeout(wq_head, condition, timeout, state) \
515 ({ \
516 int __ret = 0; \
517 struct hrtimer_sleeper __t; \
518 \
519 hrtimer_init_sleeper_on_stack(&__t, CLOCK_MONOTONIC, \
520 HRTIMER_MODE_REL); \
521 if ((timeout) != KTIME_MAX) \
522 hrtimer_start_range_ns(&__t.timer, timeout, \
523 current->timer_slack_ns, \
524 HRTIMER_MODE_REL); \
525 \
526 __ret = ___wait_event(wq_head, condition, state, 0, 0, \
527 if (!__t.task) { \
528 __ret = -ETIME; \
529 break; \
530 } \
531 schedule()); \
532 \
533 hrtimer_cancel(&__t.timer); \
534 destroy_hrtimer_on_stack(&__t.timer); \
535 __ret; \
536 })
537
538 /**
539 * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses
540 * @wq_head: the waitqueue to wait on
541 * @condition: a C expression for the event to wait for
542 * @timeout: timeout, as a ktime_t
543 *
544 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
545 * @condition evaluates to true or a signal is received.
546 * The @condition is checked each time the waitqueue @wq_head is woken up.
547 *
548 * wake_up() has to be called after changing any variable that could
549 * change the result of the wait condition.
550 *
551 * The function returns 0 if @condition became true, or -ETIME if the timeout
552 * elapsed.
553 */
554 #define wait_event_hrtimeout(wq_head, condition, timeout) \
555 ({ \
556 int __ret = 0; \
557 might_sleep(); \
558 if (!(condition)) \
559 __ret = __wait_event_hrtimeout(wq_head, condition, timeout, \
560 TASK_UNINTERRUPTIBLE); \
561 __ret; \
562 })
563
564 /**
565 * wait_event_interruptible_hrtimeout - sleep until a condition gets true or a timeout elapses
566 * @wq: the waitqueue to wait on
567 * @condition: a C expression for the event to wait for
568 * @timeout: timeout, as a ktime_t
569 *
570 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
571 * @condition evaluates to true or a signal is received.
572 * The @condition is checked each time the waitqueue @wq is woken up.
573 *
574 * wake_up() has to be called after changing any variable that could
575 * change the result of the wait condition.
576 *
577 * The function returns 0 if @condition became true, -ERESTARTSYS if it was
578 * interrupted by a signal, or -ETIME if the timeout elapsed.
579 */
580 #define wait_event_interruptible_hrtimeout(wq, condition, timeout) \
581 ({ \
582 long __ret = 0; \
583 might_sleep(); \
584 if (!(condition)) \
585 __ret = __wait_event_hrtimeout(wq, condition, timeout, \
586 TASK_INTERRUPTIBLE); \
587 __ret; \
588 })
589
590 #define __wait_event_interruptible_exclusive(wq, condition) \
591 ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \
592 schedule())
593
594 #define wait_event_interruptible_exclusive(wq, condition) \
595 ({ \
596 int __ret = 0; \
597 might_sleep(); \
598 if (!(condition)) \
599 __ret = __wait_event_interruptible_exclusive(wq, condition); \
600 __ret; \
601 })
602
603 #define __wait_event_killable_exclusive(wq, condition) \
604 ___wait_event(wq, condition, TASK_KILLABLE, 1, 0, \
605 schedule())
606
607 #define wait_event_killable_exclusive(wq, condition) \
608 ({ \
609 int __ret = 0; \
610 might_sleep(); \
611 if (!(condition)) \
612 __ret = __wait_event_killable_exclusive(wq, condition); \
613 __ret; \
614 })
615
616
617 #define __wait_event_freezable_exclusive(wq, condition) \
618 ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \
619 freezable_schedule())
620
621 #define wait_event_freezable_exclusive(wq, condition) \
622 ({ \
623 int __ret = 0; \
624 might_sleep(); \
625 if (!(condition)) \
626 __ret = __wait_event_freezable_exclusive(wq, condition); \
627 __ret; \
628 })
629
630 /**
631 * wait_event_idle - wait for a condition without contributing to system load
632 * @wq_head: the waitqueue to wait on
633 * @condition: a C expression for the event to wait for
634 *
635 * The process is put to sleep (TASK_IDLE) until the
636 * @condition evaluates to true.
637 * The @condition is checked each time the waitqueue @wq_head is woken up.
638 *
639 * wake_up() has to be called after changing any variable that could
640 * change the result of the wait condition.
641 *
642 */
643 #define wait_event_idle(wq_head, condition) \
644 do { \
645 might_sleep(); \
646 if (!(condition)) \
647 ___wait_event(wq_head, condition, TASK_IDLE, 0, 0, schedule()); \
648 } while (0)
649
650 /**
651 * wait_event_idle_exclusive - wait for a condition with contributing to system load
652 * @wq_head: the waitqueue to wait on
653 * @condition: a C expression for the event to wait for
654 *
655 * The process is put to sleep (TASK_IDLE) until the
656 * @condition evaluates to true.
657 * The @condition is checked each time the waitqueue @wq_head is woken up.
658 *
659 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
660 * set thus if other processes wait on the same list, when this
661 * process is woken further processes are not considered.
662 *
663 * wake_up() has to be called after changing any variable that could
664 * change the result of the wait condition.
665 *
666 */
667 #define wait_event_idle_exclusive(wq_head, condition) \
668 do { \
669 might_sleep(); \
670 if (!(condition)) \
671 ___wait_event(wq_head, condition, TASK_IDLE, 1, 0, schedule()); \
672 } while (0)
673
674 #define __wait_event_idle_timeout(wq_head, condition, timeout) \
675 ___wait_event(wq_head, ___wait_cond_timeout(condition), \
676 TASK_IDLE, 0, timeout, \
677 __ret = schedule_timeout(__ret))
678
679 /**
680 * wait_event_idle_timeout - sleep without load until a condition becomes true or a timeout elapses
681 * @wq_head: the waitqueue to wait on
682 * @condition: a C expression for the event to wait for
683 * @timeout: timeout, in jiffies
684 *
685 * The process is put to sleep (TASK_IDLE) until the
686 * @condition evaluates to true. The @condition is checked each time
687 * the waitqueue @wq_head is woken up.
688 *
689 * wake_up() has to be called after changing any variable that could
690 * change the result of the wait condition.
691 *
692 * Returns:
693 * 0 if the @condition evaluated to %false after the @timeout elapsed,
694 * 1 if the @condition evaluated to %true after the @timeout elapsed,
695 * or the remaining jiffies (at least 1) if the @condition evaluated
696 * to %true before the @timeout elapsed.
697 */
698 #define wait_event_idle_timeout(wq_head, condition, timeout) \
699 ({ \
700 long __ret = timeout; \
701 might_sleep(); \
702 if (!___wait_cond_timeout(condition)) \
703 __ret = __wait_event_idle_timeout(wq_head, condition, timeout); \
704 __ret; \
705 })
706
707 #define __wait_event_idle_exclusive_timeout(wq_head, condition, timeout) \
708 ___wait_event(wq_head, ___wait_cond_timeout(condition), \
709 TASK_IDLE, 1, timeout, \
710 __ret = schedule_timeout(__ret))
711
712 /**
713 * wait_event_idle_exclusive_timeout - sleep without load until a condition becomes true or a timeout elapses
714 * @wq_head: the waitqueue to wait on
715 * @condition: a C expression for the event to wait for
716 * @timeout: timeout, in jiffies
717 *
718 * The process is put to sleep (TASK_IDLE) until the
719 * @condition evaluates to true. The @condition is checked each time
720 * the waitqueue @wq_head is woken up.
721 *
722 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
723 * set thus if other processes wait on the same list, when this
724 * process is woken further processes are not considered.
725 *
726 * wake_up() has to be called after changing any variable that could
727 * change the result of the wait condition.
728 *
729 * Returns:
730 * 0 if the @condition evaluated to %false after the @timeout elapsed,
731 * 1 if the @condition evaluated to %true after the @timeout elapsed,
732 * or the remaining jiffies (at least 1) if the @condition evaluated
733 * to %true before the @timeout elapsed.
734 */
735 #define wait_event_idle_exclusive_timeout(wq_head, condition, timeout) \
736 ({ \
737 long __ret = timeout; \
738 might_sleep(); \
739 if (!___wait_cond_timeout(condition)) \
740 __ret = __wait_event_idle_exclusive_timeout(wq_head, condition, timeout);\
741 __ret; \
742 })
743
744 extern int do_wait_intr(wait_queue_head_t *, wait_queue_entry_t *);
745 extern int do_wait_intr_irq(wait_queue_head_t *, wait_queue_entry_t *);
746
747 #define __wait_event_interruptible_locked(wq, condition, exclusive, fn) \
748 ({ \
749 int __ret; \
750 DEFINE_WAIT(__wait); \
751 if (exclusive) \
752 __wait.flags |= WQ_FLAG_EXCLUSIVE; \
753 do { \
754 __ret = fn(&(wq), &__wait); \
755 if (__ret) \
756 break; \
757 } while (!(condition)); \
758 __remove_wait_queue(&(wq), &__wait); \
759 __set_current_state(TASK_RUNNING); \
760 __ret; \
761 })
762
763
764 /**
765 * wait_event_interruptible_locked - sleep until a condition gets true
766 * @wq: the waitqueue to wait on
767 * @condition: a C expression for the event to wait for
768 *
769 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
770 * @condition evaluates to true or a signal is received.
771 * The @condition is checked each time the waitqueue @wq is woken up.
772 *
773 * It must be called with wq.lock being held. This spinlock is
774 * unlocked while sleeping but @condition testing is done while lock
775 * is held and when this macro exits the lock is held.
776 *
777 * The lock is locked/unlocked using spin_lock()/spin_unlock()
778 * functions which must match the way they are locked/unlocked outside
779 * of this macro.
780 *
781 * wake_up_locked() has to be called after changing any variable that could
782 * change the result of the wait condition.
783 *
784 * The function will return -ERESTARTSYS if it was interrupted by a
785 * signal and 0 if @condition evaluated to true.
786 */
787 #define wait_event_interruptible_locked(wq, condition) \
788 ((condition) \
789 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr))
790
791 /**
792 * wait_event_interruptible_locked_irq - sleep until a condition gets true
793 * @wq: the waitqueue to wait on
794 * @condition: a C expression for the event to wait for
795 *
796 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
797 * @condition evaluates to true or a signal is received.
798 * The @condition is checked each time the waitqueue @wq is woken up.
799 *
800 * It must be called with wq.lock being held. This spinlock is
801 * unlocked while sleeping but @condition testing is done while lock
802 * is held and when this macro exits the lock is held.
803 *
804 * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
805 * functions which must match the way they are locked/unlocked outside
806 * of this macro.
807 *
808 * wake_up_locked() has to be called after changing any variable that could
809 * change the result of the wait condition.
810 *
811 * The function will return -ERESTARTSYS if it was interrupted by a
812 * signal and 0 if @condition evaluated to true.
813 */
814 #define wait_event_interruptible_locked_irq(wq, condition) \
815 ((condition) \
816 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr_irq))
817
818 /**
819 * wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true
820 * @wq: the waitqueue to wait on
821 * @condition: a C expression for the event to wait for
822 *
823 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
824 * @condition evaluates to true or a signal is received.
825 * The @condition is checked each time the waitqueue @wq is woken up.
826 *
827 * It must be called with wq.lock being held. This spinlock is
828 * unlocked while sleeping but @condition testing is done while lock
829 * is held and when this macro exits the lock is held.
830 *
831 * The lock is locked/unlocked using spin_lock()/spin_unlock()
832 * functions which must match the way they are locked/unlocked outside
833 * of this macro.
834 *
835 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
836 * set thus when other process waits process on the list if this
837 * process is awaken further processes are not considered.
838 *
839 * wake_up_locked() has to be called after changing any variable that could
840 * change the result of the wait condition.
841 *
842 * The function will return -ERESTARTSYS if it was interrupted by a
843 * signal and 0 if @condition evaluated to true.
844 */
845 #define wait_event_interruptible_exclusive_locked(wq, condition) \
846 ((condition) \
847 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr))
848
849 /**
850 * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true
851 * @wq: the waitqueue to wait on
852 * @condition: a C expression for the event to wait for
853 *
854 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
855 * @condition evaluates to true or a signal is received.
856 * The @condition is checked each time the waitqueue @wq is woken up.
857 *
858 * It must be called with wq.lock being held. This spinlock is
859 * unlocked while sleeping but @condition testing is done while lock
860 * is held and when this macro exits the lock is held.
861 *
862 * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
863 * functions which must match the way they are locked/unlocked outside
864 * of this macro.
865 *
866 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
867 * set thus when other process waits process on the list if this
868 * process is awaken further processes are not considered.
869 *
870 * wake_up_locked() has to be called after changing any variable that could
871 * change the result of the wait condition.
872 *
873 * The function will return -ERESTARTSYS if it was interrupted by a
874 * signal and 0 if @condition evaluated to true.
875 */
876 #define wait_event_interruptible_exclusive_locked_irq(wq, condition) \
877 ((condition) \
878 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr_irq))
879
880
881 #define __wait_event_killable(wq, condition) \
882 ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule())
883
884 /**
885 * wait_event_killable - sleep until a condition gets true
886 * @wq_head: the waitqueue to wait on
887 * @condition: a C expression for the event to wait for
888 *
889 * The process is put to sleep (TASK_KILLABLE) until the
890 * @condition evaluates to true or a signal is received.
891 * The @condition is checked each time the waitqueue @wq_head is woken up.
892 *
893 * wake_up() has to be called after changing any variable that could
894 * change the result of the wait condition.
895 *
896 * The function will return -ERESTARTSYS if it was interrupted by a
897 * signal and 0 if @condition evaluated to true.
898 */
899 #define wait_event_killable(wq_head, condition) \
900 ({ \
901 int __ret = 0; \
902 might_sleep(); \
903 if (!(condition)) \
904 __ret = __wait_event_killable(wq_head, condition); \
905 __ret; \
906 })
907
908 #define __wait_event_killable_timeout(wq_head, condition, timeout) \
909 ___wait_event(wq_head, ___wait_cond_timeout(condition), \
910 TASK_KILLABLE, 0, timeout, \
911 __ret = schedule_timeout(__ret))
912
913 /**
914 * wait_event_killable_timeout - sleep until a condition gets true or a timeout elapses
915 * @wq_head: the waitqueue to wait on
916 * @condition: a C expression for the event to wait for
917 * @timeout: timeout, in jiffies
918 *
919 * The process is put to sleep (TASK_KILLABLE) until the
920 * @condition evaluates to true or a kill signal is received.
921 * The @condition is checked each time the waitqueue @wq_head is woken up.
922 *
923 * wake_up() has to be called after changing any variable that could
924 * change the result of the wait condition.
925 *
926 * Returns:
927 * 0 if the @condition evaluated to %false after the @timeout elapsed,
928 * 1 if the @condition evaluated to %true after the @timeout elapsed,
929 * the remaining jiffies (at least 1) if the @condition evaluated
930 * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
931 * interrupted by a kill signal.
932 *
933 * Only kill signals interrupt this process.
934 */
935 #define wait_event_killable_timeout(wq_head, condition, timeout) \
936 ({ \
937 long __ret = timeout; \
938 might_sleep(); \
939 if (!___wait_cond_timeout(condition)) \
940 __ret = __wait_event_killable_timeout(wq_head, \
941 condition, timeout); \
942 __ret; \
943 })
944
945
946 #define __wait_event_lock_irq(wq_head, condition, lock, cmd) \
947 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
948 spin_unlock_irq(&lock); \
949 cmd; \
950 schedule(); \
951 spin_lock_irq(&lock))
952
953 /**
954 * wait_event_lock_irq_cmd - sleep until a condition gets true. The
955 * condition is checked under the lock. This
956 * is expected to be called with the lock
957 * taken.
958 * @wq_head: the waitqueue to wait on
959 * @condition: a C expression for the event to wait for
960 * @lock: a locked spinlock_t, which will be released before cmd
961 * and schedule() and reacquired afterwards.
962 * @cmd: a command which is invoked outside the critical section before
963 * sleep
964 *
965 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
966 * @condition evaluates to true. The @condition is checked each time
967 * the waitqueue @wq_head is woken up.
968 *
969 * wake_up() has to be called after changing any variable that could
970 * change the result of the wait condition.
971 *
972 * This is supposed to be called while holding the lock. The lock is
973 * dropped before invoking the cmd and going to sleep and is reacquired
974 * afterwards.
975 */
976 #define wait_event_lock_irq_cmd(wq_head, condition, lock, cmd) \
977 do { \
978 if (condition) \
979 break; \
980 __wait_event_lock_irq(wq_head, condition, lock, cmd); \
981 } while (0)
982
983 /**
984 * wait_event_lock_irq - sleep until a condition gets true. The
985 * condition is checked under the lock. This
986 * is expected to be called with the lock
987 * taken.
988 * @wq_head: the waitqueue to wait on
989 * @condition: a C expression for the event to wait for
990 * @lock: a locked spinlock_t, which will be released before schedule()
991 * and reacquired afterwards.
992 *
993 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
994 * @condition evaluates to true. The @condition is checked each time
995 * the waitqueue @wq_head is woken up.
996 *
997 * wake_up() has to be called after changing any variable that could
998 * change the result of the wait condition.
999 *
1000 * This is supposed to be called while holding the lock. The lock is
1001 * dropped before going to sleep and is reacquired afterwards.
1002 */
1003 #define wait_event_lock_irq(wq_head, condition, lock) \
1004 do { \
1005 if (condition) \
1006 break; \
1007 __wait_event_lock_irq(wq_head, condition, lock, ); \
1008 } while (0)
1009
1010
1011 #define __wait_event_interruptible_lock_irq(wq_head, condition, lock, cmd) \
1012 ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0, \
1013 spin_unlock_irq(&lock); \
1014 cmd; \
1015 schedule(); \
1016 spin_lock_irq(&lock))
1017
1018 /**
1019 * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true.
1020 * The condition is checked under the lock. This is expected to
1021 * be called with the lock taken.
1022 * @wq_head: the waitqueue to wait on
1023 * @condition: a C expression for the event to wait for
1024 * @lock: a locked spinlock_t, which will be released before cmd and
1025 * schedule() and reacquired afterwards.
1026 * @cmd: a command which is invoked outside the critical section before
1027 * sleep
1028 *
1029 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
1030 * @condition evaluates to true or a signal is received. The @condition is
1031 * checked each time the waitqueue @wq_head is woken up.
1032 *
1033 * wake_up() has to be called after changing any variable that could
1034 * change the result of the wait condition.
1035 *
1036 * This is supposed to be called while holding the lock. The lock is
1037 * dropped before invoking the cmd and going to sleep and is reacquired
1038 * afterwards.
1039 *
1040 * The macro will return -ERESTARTSYS if it was interrupted by a signal
1041 * and 0 if @condition evaluated to true.
1042 */
1043 #define wait_event_interruptible_lock_irq_cmd(wq_head, condition, lock, cmd) \
1044 ({ \
1045 int __ret = 0; \
1046 if (!(condition)) \
1047 __ret = __wait_event_interruptible_lock_irq(wq_head, \
1048 condition, lock, cmd); \
1049 __ret; \
1050 })
1051
1052 /**
1053 * wait_event_interruptible_lock_irq - sleep until a condition gets true.
1054 * The condition is checked under the lock. This is expected
1055 * to be called with the lock taken.
1056 * @wq_head: the waitqueue to wait on
1057 * @condition: a C expression for the event to wait for
1058 * @lock: a locked spinlock_t, which will be released before schedule()
1059 * and reacquired afterwards.
1060 *
1061 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
1062 * @condition evaluates to true or signal is received. The @condition is
1063 * checked each time the waitqueue @wq_head is woken up.
1064 *
1065 * wake_up() has to be called after changing any variable that could
1066 * change the result of the wait condition.
1067 *
1068 * This is supposed to be called while holding the lock. The lock is
1069 * dropped before going to sleep and is reacquired afterwards.
1070 *
1071 * The macro will return -ERESTARTSYS if it was interrupted by a signal
1072 * and 0 if @condition evaluated to true.
1073 */
1074 #define wait_event_interruptible_lock_irq(wq_head, condition, lock) \
1075 ({ \
1076 int __ret = 0; \
1077 if (!(condition)) \
1078 __ret = __wait_event_interruptible_lock_irq(wq_head, \
1079 condition, lock,); \
1080 __ret; \
1081 })
1082
1083 #define __wait_event_lock_irq_timeout(wq_head, condition, lock, timeout, state) \
1084 ___wait_event(wq_head, ___wait_cond_timeout(condition), \
1085 state, 0, timeout, \
1086 spin_unlock_irq(&lock); \
1087 __ret = schedule_timeout(__ret); \
1088 spin_lock_irq(&lock));
1089
1090 /**
1091 * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets
1092 * true or a timeout elapses. The condition is checked under
1093 * the lock. This is expected to be called with the lock taken.
1094 * @wq_head: the waitqueue to wait on
1095 * @condition: a C expression for the event to wait for
1096 * @lock: a locked spinlock_t, which will be released before schedule()
1097 * and reacquired afterwards.
1098 * @timeout: timeout, in jiffies
1099 *
1100 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
1101 * @condition evaluates to true or signal is received. The @condition is
1102 * checked each time the waitqueue @wq_head is woken up.
1103 *
1104 * wake_up() has to be called after changing any variable that could
1105 * change the result of the wait condition.
1106 *
1107 * This is supposed to be called while holding the lock. The lock is
1108 * dropped before going to sleep and is reacquired afterwards.
1109 *
1110 * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
1111 * was interrupted by a signal, and the remaining jiffies otherwise
1112 * if the condition evaluated to true before the timeout elapsed.
1113 */
1114 #define wait_event_interruptible_lock_irq_timeout(wq_head, condition, lock, \
1115 timeout) \
1116 ({ \
1117 long __ret = timeout; \
1118 if (!___wait_cond_timeout(condition)) \
1119 __ret = __wait_event_lock_irq_timeout( \
1120 wq_head, condition, lock, timeout, \
1121 TASK_INTERRUPTIBLE); \
1122 __ret; \
1123 })
1124
1125 #define wait_event_lock_irq_timeout(wq_head, condition, lock, timeout) \
1126 ({ \
1127 long __ret = timeout; \
1128 if (!___wait_cond_timeout(condition)) \
1129 __ret = __wait_event_lock_irq_timeout( \
1130 wq_head, condition, lock, timeout, \
1131 TASK_UNINTERRUPTIBLE); \
1132 __ret; \
1133 })
1134
1135 /*
1136 * Waitqueues which are removed from the waitqueue_head at wakeup time
1137 */
1138 void prepare_to_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
1139 bool prepare_to_wait_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
1140 long prepare_to_wait_event(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
1141 void finish_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
1142 long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout);
1143 int woken_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);
1144 int autoremove_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);
1145
1146 #define DEFINE_WAIT_FUNC(name, function) \
1147 struct wait_queue_entry name = { \
1148 .private = current, \
1149 .func = function, \
1150 .entry = LIST_HEAD_INIT((name).entry), \
1151 }
1152
1153 #define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function)
1154
1155 #define init_wait(wait) \
1156 do { \
1157 (wait)->private = current; \
1158 (wait)->func = autoremove_wake_function; \
1159 INIT_LIST_HEAD(&(wait)->entry); \
1160 (wait)->flags = 0; \
1161 } while (0)
1162
1163 bool try_invoke_on_locked_down_task(struct task_struct *p, bool (*func)(struct task_struct *t, void *arg), void *arg);
1164
1165 #endif /* _LINUX_WAIT_H */
1166
