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