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unify {de,}mangle_poll(), get rid of kernel-side POLL...
[cris-mirror.git] / include / linux / wait.h
blob55a611486bac1aea59e87f00ee3f80f2d82185a7
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
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
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 */
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 */
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
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
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
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
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
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 extern int do_wait_intr(wait_queue_head_t *, wait_queue_entry_t *);
603 extern int do_wait_intr_irq(wait_queue_head_t *, wait_queue_entry_t *);
604
605 #define __wait_event_interruptible_locked(wq, condition, exclusive, fn) \
606 ({ \
607 int __ret; \
608 DEFINE_WAIT(__wait); \
609 if (exclusive) \
610 __wait.flags |= WQ_FLAG_EXCLUSIVE; \
611 do { \
612 __ret = fn(&(wq), &__wait); \
613 if (__ret) \
614 break; \
615 } while (!(condition)); \
616 __remove_wait_queue(&(wq), &__wait); \
617 __set_current_state(TASK_RUNNING); \
618 __ret; \
619 })
620
621
622 /**
623 * wait_event_interruptible_locked - sleep until a condition gets true
624 * @wq: 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_INTERRUPTIBLE) until the
628 * @condition evaluates to true or a signal is received.
629 * The @condition is checked each time the waitqueue @wq is woken up.
630 *
631 * It must be called with wq.lock being held. This spinlock is
632 * unlocked while sleeping but @condition testing is done while lock
633 * is held and when this macro exits the lock is held.
634 *
635 * The lock is locked/unlocked using spin_lock()/spin_unlock()
636 * functions which must match the way they are locked/unlocked outside
637 * of this macro.
638 *
639 * wake_up_locked() has to be called after changing any variable that could
640 * change the result of the wait condition.
641 *
642 * The function will return -ERESTARTSYS if it was interrupted by a
643 * signal and 0 if @condition evaluated to true.
644 */
645 #define wait_event_interruptible_locked(wq, condition) \
646 ((condition) \
647 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr))
648
649 /**
650 * wait_event_interruptible_locked_irq - sleep until a condition gets true
651 * @wq: the waitqueue to wait on
652 * @condition: a C expression for the event to wait for
653 *
654 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
655 * @condition evaluates to true or a signal is received.
656 * The @condition is checked each time the waitqueue @wq is woken up.
657 *
658 * It must be called with wq.lock being held. This spinlock is
659 * unlocked while sleeping but @condition testing is done while lock
660 * is held and when this macro exits the lock is held.
661 *
662 * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
663 * functions which must match the way they are locked/unlocked outside
664 * of this macro.
665 *
666 * wake_up_locked() has to be called after changing any variable that could
667 * change the result of the wait condition.
668 *
669 * The function will return -ERESTARTSYS if it was interrupted by a
670 * signal and 0 if @condition evaluated to true.
671 */
672 #define wait_event_interruptible_locked_irq(wq, condition) \
673 ((condition) \
674 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr_irq))
675
676 /**
677 * wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true
678 * @wq: the waitqueue to wait on
679 * @condition: a C expression for the event to wait for
680 *
681 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
682 * @condition evaluates to true or a signal is received.
683 * The @condition is checked each time the waitqueue @wq is woken up.
684 *
685 * It must be called with wq.lock being held. This spinlock is
686 * unlocked while sleeping but @condition testing is done while lock
687 * is held and when this macro exits the lock is held.
688 *
689 * The lock is locked/unlocked using spin_lock()/spin_unlock()
690 * functions which must match the way they are locked/unlocked outside
691 * of this macro.
692 *
693 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
694 * set thus when other process waits process on the list if this
695 * process is awaken further processes are not considered.
696 *
697 * wake_up_locked() has to be called after changing any variable that could
698 * change the result of the wait condition.
699 *
700 * The function will return -ERESTARTSYS if it was interrupted by a
701 * signal and 0 if @condition evaluated to true.
702 */
703 #define wait_event_interruptible_exclusive_locked(wq, condition) \
704 ((condition) \
705 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr))
706
707 /**
708 * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true
709 * @wq: the waitqueue to wait on
710 * @condition: a C expression for the event to wait for
711 *
712 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
713 * @condition evaluates to true or a signal is received.
714 * The @condition is checked each time the waitqueue @wq is woken up.
715 *
716 * It must be called with wq.lock being held. This spinlock is
717 * unlocked while sleeping but @condition testing is done while lock
718 * is held and when this macro exits the lock is held.
719 *
720 * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
721 * functions which must match the way they are locked/unlocked outside
722 * of this macro.
723 *
724 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
725 * set thus when other process waits process on the list if this
726 * process is awaken further processes are not considered.
727 *
728 * wake_up_locked() has to be called after changing any variable that could
729 * change the result of the wait condition.
730 *
731 * The function will return -ERESTARTSYS if it was interrupted by a
732 * signal and 0 if @condition evaluated to true.
733 */
734 #define wait_event_interruptible_exclusive_locked_irq(wq, condition) \
735 ((condition) \
736 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr_irq))
737
738
739 #define __wait_event_killable(wq, condition) \
740 ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule())
741
742 /**
743 * wait_event_killable - sleep until a condition gets true
744 * @wq_head: the waitqueue to wait on
745 * @condition: a C expression for the event to wait for
746 *
747 * The process is put to sleep (TASK_KILLABLE) until the
748 * @condition evaluates to true or a signal is received.
749 * The @condition is checked each time the waitqueue @wq_head is woken up.
750 *
751 * wake_up() has to be called after changing any variable that could
752 * change the result of the wait condition.
753 *
754 * The function will return -ERESTARTSYS if it was interrupted by a
755 * signal and 0 if @condition evaluated to true.
756 */
757 #define wait_event_killable(wq_head, condition) \
758 ({ \
759 int __ret = 0; \
760 might_sleep(); \
761 if (!(condition)) \
762 __ret = __wait_event_killable(wq_head, condition); \
763 __ret; \
764 })
765
766 #define __wait_event_killable_timeout(wq_head, condition, timeout) \
767 ___wait_event(wq_head, ___wait_cond_timeout(condition), \
768 TASK_KILLABLE, 0, timeout, \
769 __ret = schedule_timeout(__ret))
770
771 /**
772 * wait_event_killable_timeout - sleep until a condition gets true or a timeout elapses
773 * @wq_head: the waitqueue to wait on
774 * @condition: a C expression for the event to wait for
775 * @timeout: timeout, in jiffies
776 *
777 * The process is put to sleep (TASK_KILLABLE) until the
778 * @condition evaluates to true or a kill signal is received.
779 * The @condition is checked each time the waitqueue @wq_head is woken up.
780 *
781 * wake_up() has to be called after changing any variable that could
782 * change the result of the wait condition.
783 *
784 * Returns:
785 * 0 if the @condition evaluated to %false after the @timeout elapsed,
786 * 1 if the @condition evaluated to %true after the @timeout elapsed,
787 * the remaining jiffies (at least 1) if the @condition evaluated
788 * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
789 * interrupted by a kill signal.
790 *
791 * Only kill signals interrupt this process.
792 */
793 #define wait_event_killable_timeout(wq_head, condition, timeout) \
794 ({ \
795 long __ret = timeout; \
796 might_sleep(); \
797 if (!___wait_cond_timeout(condition)) \
798 __ret = __wait_event_killable_timeout(wq_head, \
799 condition, timeout); \
800 __ret; \
801 })
802
803
804 #define __wait_event_lock_irq(wq_head, condition, lock, cmd) \
805 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
806 spin_unlock_irq(&lock); \
807 cmd; \
808 schedule(); \
809 spin_lock_irq(&lock))
810
811 /**
812 * wait_event_lock_irq_cmd - sleep until a condition gets true. The
813 * condition is checked under the lock. This
814 * is expected to be called with the lock
815 * taken.
816 * @wq_head: the waitqueue to wait on
817 * @condition: a C expression for the event to wait for
818 * @lock: a locked spinlock_t, which will be released before cmd
819 * and schedule() and reacquired afterwards.
820 * @cmd: a command which is invoked outside the critical section before
821 * sleep
822 *
823 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
824 * @condition evaluates to true. The @condition is checked each time
825 * the waitqueue @wq_head is woken up.
826 *
827 * wake_up() has to be called after changing any variable that could
828 * change the result of the wait condition.
829 *
830 * This is supposed to be called while holding the lock. The lock is
831 * dropped before invoking the cmd and going to sleep and is reacquired
832 * afterwards.
833 */
834 #define wait_event_lock_irq_cmd(wq_head, condition, lock, cmd) \
835 do { \
836 if (condition) \
837 break; \
838 __wait_event_lock_irq(wq_head, condition, lock, cmd); \
839 } while (0)
840
841 /**
842 * wait_event_lock_irq - sleep until a condition gets true. The
843 * condition is checked under the lock. This
844 * is expected to be called with the lock
845 * taken.
846 * @wq_head: the waitqueue to wait on
847 * @condition: a C expression for the event to wait for
848 * @lock: a locked spinlock_t, which will be released before schedule()
849 * and reacquired afterwards.
850 *
851 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
852 * @condition evaluates to true. The @condition is checked each time
853 * the waitqueue @wq_head is woken up.
854 *
855 * wake_up() has to be called after changing any variable that could
856 * change the result of the wait condition.
857 *
858 * This is supposed to be called while holding the lock. The lock is
859 * dropped before going to sleep and is reacquired afterwards.
860 */
861 #define wait_event_lock_irq(wq_head, condition, lock) \
862 do { \
863 if (condition) \
864 break; \
865 __wait_event_lock_irq(wq_head, condition, lock, ); \
866 } while (0)
867
868
869 #define __wait_event_interruptible_lock_irq(wq_head, condition, lock, cmd) \
870 ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0, \
871 spin_unlock_irq(&lock); \
872 cmd; \
873 schedule(); \
874 spin_lock_irq(&lock))
875
876 /**
877 * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true.
878 * The condition is checked under the lock. This is expected to
879 * be called with the lock taken.
880 * @wq_head: the waitqueue to wait on
881 * @condition: a C expression for the event to wait for
882 * @lock: a locked spinlock_t, which will be released before cmd and
883 * schedule() and reacquired afterwards.
884 * @cmd: a command which is invoked outside the critical section before
885 * sleep
886 *
887 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
888 * @condition evaluates to true or a signal is received. The @condition is
889 * checked each time the waitqueue @wq_head is woken up.
890 *
891 * wake_up() has to be called after changing any variable that could
892 * change the result of the wait condition.
893 *
894 * This is supposed to be called while holding the lock. The lock is
895 * dropped before invoking the cmd and going to sleep and is reacquired
896 * afterwards.
897 *
898 * The macro will return -ERESTARTSYS if it was interrupted by a signal
899 * and 0 if @condition evaluated to true.
900 */
901 #define wait_event_interruptible_lock_irq_cmd(wq_head, condition, lock, cmd) \
902 ({ \
903 int __ret = 0; \
904 if (!(condition)) \
905 __ret = __wait_event_interruptible_lock_irq(wq_head, \
906 condition, lock, cmd); \
907 __ret; \
908 })
909
910 /**
911 * wait_event_interruptible_lock_irq - sleep until a condition gets true.
912 * The condition is checked under the lock. This is expected
913 * to be called with the lock taken.
914 * @wq_head: the waitqueue to wait on
915 * @condition: a C expression for the event to wait for
916 * @lock: a locked spinlock_t, which will be released before schedule()
917 * and reacquired afterwards.
918 *
919 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
920 * @condition evaluates to true or signal is received. The @condition is
921 * 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 * This is supposed to be called while holding the lock. The lock is
927 * dropped before going to sleep and is reacquired afterwards.
928 *
929 * The macro will return -ERESTARTSYS if it was interrupted by a signal
930 * and 0 if @condition evaluated to true.
931 */
932 #define wait_event_interruptible_lock_irq(wq_head, condition, lock) \
933 ({ \
934 int __ret = 0; \
935 if (!(condition)) \
936 __ret = __wait_event_interruptible_lock_irq(wq_head, \
937 condition, lock,); \
938 __ret; \
939 })
940
941 #define __wait_event_interruptible_lock_irq_timeout(wq_head, condition, \
942 lock, timeout) \
943 ___wait_event(wq_head, ___wait_cond_timeout(condition), \
944 TASK_INTERRUPTIBLE, 0, timeout, \
945 spin_unlock_irq(&lock); \
946 __ret = schedule_timeout(__ret); \
947 spin_lock_irq(&lock));
948
949 /**
950 * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets
951 * true or a timeout elapses. The condition is checked under
952 * the lock. This is expected to be called with the lock taken.
953 * @wq_head: the waitqueue to wait on
954 * @condition: a C expression for the event to wait for
955 * @lock: a locked spinlock_t, which will be released before schedule()
956 * and reacquired afterwards.
957 * @timeout: timeout, in jiffies
958 *
959 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
960 * @condition evaluates to true or signal is received. The @condition is
961 * checked each time the waitqueue @wq_head is woken up.
962 *
963 * wake_up() has to be called after changing any variable that could
964 * change the result of the wait condition.
965 *
966 * This is supposed to be called while holding the lock. The lock is
967 * dropped before going to sleep and is reacquired afterwards.
968 *
969 * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
970 * was interrupted by a signal, and the remaining jiffies otherwise
971 * if the condition evaluated to true before the timeout elapsed.
972 */
973 #define wait_event_interruptible_lock_irq_timeout(wq_head, condition, lock, \
974 timeout) \
975 ({ \
976 long __ret = timeout; \
977 if (!___wait_cond_timeout(condition)) \
978 __ret = __wait_event_interruptible_lock_irq_timeout( \
979 wq_head, condition, lock, timeout); \
980 __ret; \
981 })
982
983 /*
984 * Waitqueues which are removed from the waitqueue_head at wakeup time
985 */
986 void prepare_to_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
987 void prepare_to_wait_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
988 long prepare_to_wait_event(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
989 void finish_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
990 long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout);
991 int woken_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);
992 int autoremove_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);
993
994 #define DEFINE_WAIT_FUNC(name, function) \
995 struct wait_queue_entry name = { \
996 .private = current, \
997 .func = function, \
998 .entry = LIST_HEAD_INIT((name).entry), \
999 }
1000
1001 #define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function)
1002
1003 #define init_wait(wait) \
1004 do { \
1005 (wait)->private = current; \
1006 (wait)->func = autoremove_wake_function; \
1007 INIT_LIST_HEAD(&(wait)->entry); \
1008 (wait)->flags = 0; \
1009 } while (0)
1010
1011 #endif /* _LINUX_WAIT_H */
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