5 #include <linux/list.h>
6 #include <linux/stddef.h>
7 #include <linux/spinlock.h>
8 #include <asm/current.h>
9 #include <uapi/linux/wait.h>
11 typedef struct __wait_queue wait_queue_t;
12 typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, void *key);
13 int default_wake_function(wait_queue_t *wait, unsigned mode, int flags, void *key);
17 #define WQ_FLAG_EXCLUSIVE 0x01
19 wait_queue_func_t func;
20 struct list_head task_list;
26 #define WAIT_ATOMIC_T_BIT_NR -1
29 struct wait_bit_queue {
30 struct wait_bit_key key;
34 struct __wait_queue_head {
36 struct list_head task_list;
38 typedef struct __wait_queue_head wait_queue_head_t;
43 * Macros for declaration and initialisaton of the datatypes
46 #define __WAITQUEUE_INITIALIZER(name, tsk) { \
48 .func = default_wake_function, \
49 .task_list = { NULL, NULL } }
51 #define DECLARE_WAITQUEUE(name, tsk) \
52 wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk)
54 #define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \
55 .lock = __SPIN_LOCK_UNLOCKED(name.lock), \
56 .task_list = { &(name).task_list, &(name).task_list } }
58 #define DECLARE_WAIT_QUEUE_HEAD(name) \
59 wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name)
61 #define __WAIT_BIT_KEY_INITIALIZER(word, bit) \
62 { .flags = word, .bit_nr = bit, }
64 #define __WAIT_ATOMIC_T_KEY_INITIALIZER(p) \
65 { .flags = p, .bit_nr = WAIT_ATOMIC_T_BIT_NR, }
67 extern void __init_waitqueue_head(wait_queue_head_t *q, const char *name, struct lock_class_key *);
69 #define init_waitqueue_head(q) \
71 static struct lock_class_key __key; \
73 __init_waitqueue_head((q), #q, &__key); \
77 # define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \
78 ({ init_waitqueue_head(&name); name; })
79 # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \
80 wait_queue_head_t name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
82 # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name)
85 static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p)
89 q->func = default_wake_function;
92 static inline void init_waitqueue_func_entry(wait_queue_t *q,
93 wait_queue_func_t func)
100 static inline int waitqueue_active(wait_queue_head_t *q)
102 return !list_empty(&q->task_list);
105 extern void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait);
106 extern void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait);
107 extern void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait);
109 static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new)
111 list_add(&new->task_list, &head->task_list);
115 * Used for wake-one threads:
117 static inline void __add_wait_queue_exclusive(wait_queue_head_t *q,
120 wait->flags |= WQ_FLAG_EXCLUSIVE;
121 __add_wait_queue(q, wait);
124 static inline void __add_wait_queue_tail(wait_queue_head_t *head,
127 list_add_tail(&new->task_list, &head->task_list);
130 static inline void __add_wait_queue_tail_exclusive(wait_queue_head_t *q,
133 wait->flags |= WQ_FLAG_EXCLUSIVE;
134 __add_wait_queue_tail(q, wait);
137 static inline void __remove_wait_queue(wait_queue_head_t *head,
140 list_del(&old->task_list);
143 void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key);
144 void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key);
145 void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr,
147 void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr);
148 void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr);
149 void __wake_up_bit(wait_queue_head_t *, void *, int);
150 int __wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned);
151 int __wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned);
152 void wake_up_bit(void *, int);
153 void wake_up_atomic_t(atomic_t *);
154 int out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned);
155 int out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned);
156 int out_of_line_wait_on_atomic_t(atomic_t *, int (*)(atomic_t *), unsigned);
157 wait_queue_head_t *bit_waitqueue(void *, int);
159 #define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL)
160 #define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL)
161 #define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL)
162 #define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL, 1)
163 #define wake_up_all_locked(x) __wake_up_locked((x), TASK_NORMAL, 0)
165 #define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
166 #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
167 #define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
168 #define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE, 1)
171 * Wakeup macros to be used to report events to the targets.
173 #define wake_up_poll(x, m) \
174 __wake_up(x, TASK_NORMAL, 1, (void *) (m))
175 #define wake_up_locked_poll(x, m) \
176 __wake_up_locked_key((x), TASK_NORMAL, (void *) (m))
177 #define wake_up_interruptible_poll(x, m) \
178 __wake_up(x, TASK_INTERRUPTIBLE, 1, (void *) (m))
179 #define wake_up_interruptible_sync_poll(x, m) \
180 __wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, (void *) (m))
182 #define ___wait_cond_timeout(condition, ret) \
184 bool __cond = (condition); \
185 if (__cond && !ret) \
190 #define ___wait_signal_pending(state) \
191 ((state == TASK_INTERRUPTIBLE && signal_pending(current)) || \
192 (state == TASK_KILLABLE && fatal_signal_pending(current)))
194 #define ___wait_nop_ret int ret __always_unused
196 #define ___wait_event(wq, condition, state, exclusive, ret, cmd) \
199 DEFINE_WAIT(__wait); \
203 prepare_to_wait_exclusive(&wq, &__wait, state); \
205 prepare_to_wait(&wq, &__wait, state); \
210 if (___wait_signal_pending(state)) { \
211 ret = -ERESTARTSYS; \
213 abort_exclusive_wait(&wq, &__wait, \
222 finish_wait(&wq, &__wait); \
226 #define __wait_event(wq, condition) \
227 ___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, \
228 ___wait_nop_ret, schedule())
231 * wait_event - sleep until a condition gets true
232 * @wq: the waitqueue to wait on
233 * @condition: a C expression for the event to wait for
235 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
236 * @condition evaluates to true. The @condition is checked each time
237 * the waitqueue @wq is woken up.
239 * wake_up() has to be called after changing any variable that could
240 * change the result of the wait condition.
242 #define wait_event(wq, condition) \
246 __wait_event(wq, condition); \
249 #define __wait_event_timeout(wq, condition, ret) \
250 ___wait_event(wq, ___wait_cond_timeout(condition, ret), \
251 TASK_UNINTERRUPTIBLE, 0, ret, \
252 ret = schedule_timeout(ret))
255 * wait_event_timeout - sleep until a condition gets true or a timeout elapses
256 * @wq: the waitqueue to wait on
257 * @condition: a C expression for the event to wait for
258 * @timeout: timeout, in jiffies
260 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
261 * @condition evaluates to true. The @condition is checked each time
262 * the waitqueue @wq is woken up.
264 * wake_up() has to be called after changing any variable that could
265 * change the result of the wait condition.
267 * The function returns 0 if the @timeout elapsed, or the remaining
268 * jiffies (at least 1) if the @condition evaluated to %true before
269 * the @timeout elapsed.
271 #define wait_event_timeout(wq, condition, timeout) \
273 long __ret = timeout; \
275 __wait_event_timeout(wq, condition, __ret); \
279 #define __wait_event_interruptible(wq, condition, ret) \
280 ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, ret, \
284 * wait_event_interruptible - sleep until a condition gets true
285 * @wq: the waitqueue to wait on
286 * @condition: a C expression for the event to wait for
288 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
289 * @condition evaluates to true or a signal is received.
290 * The @condition is checked each time the waitqueue @wq is woken up.
292 * wake_up() has to be called after changing any variable that could
293 * change the result of the wait condition.
295 * The function will return -ERESTARTSYS if it was interrupted by a
296 * signal and 0 if @condition evaluated to true.
298 #define wait_event_interruptible(wq, condition) \
302 __wait_event_interruptible(wq, condition, __ret); \
306 #define __wait_event_interruptible_timeout(wq, condition, ret) \
308 DEFINE_WAIT(__wait); \
311 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
312 if (___wait_cond_timeout(condition, ret)) \
314 if (signal_pending(current)) { \
315 ret = -ERESTARTSYS; \
318 ret = schedule_timeout(ret); \
320 finish_wait(&wq, &__wait); \
324 * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
325 * @wq: the waitqueue to wait on
326 * @condition: a C expression for the event to wait for
327 * @timeout: timeout, in jiffies
329 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
330 * @condition evaluates to true or a signal is received.
331 * The @condition is checked each time the waitqueue @wq is woken up.
333 * wake_up() has to be called after changing any variable that could
334 * change the result of the wait condition.
337 * 0 if the @timeout elapsed, -%ERESTARTSYS if it was interrupted by
338 * a signal, or the remaining jiffies (at least 1) if the @condition
339 * evaluated to %true before the @timeout elapsed.
341 #define wait_event_interruptible_timeout(wq, condition, timeout) \
343 long __ret = timeout; \
345 __wait_event_interruptible_timeout(wq, condition, __ret); \
349 #define __wait_event_hrtimeout(wq, condition, timeout, state) \
352 DEFINE_WAIT(__wait); \
353 struct hrtimer_sleeper __t; \
355 hrtimer_init_on_stack(&__t.timer, CLOCK_MONOTONIC, \
357 hrtimer_init_sleeper(&__t, current); \
358 if ((timeout).tv64 != KTIME_MAX) \
359 hrtimer_start_range_ns(&__t.timer, timeout, \
360 current->timer_slack_ns, \
364 prepare_to_wait(&wq, &__wait, state); \
367 if (state == TASK_INTERRUPTIBLE && \
368 signal_pending(current)) { \
369 __ret = -ERESTARTSYS; \
379 hrtimer_cancel(&__t.timer); \
380 destroy_hrtimer_on_stack(&__t.timer); \
381 finish_wait(&wq, &__wait); \
386 * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses
387 * @wq: the waitqueue to wait on
388 * @condition: a C expression for the event to wait for
389 * @timeout: timeout, as a ktime_t
391 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
392 * @condition evaluates to true or a signal is received.
393 * The @condition is checked each time the waitqueue @wq is woken up.
395 * wake_up() has to be called after changing any variable that could
396 * change the result of the wait condition.
398 * The function returns 0 if @condition became true, or -ETIME if the timeout
401 #define wait_event_hrtimeout(wq, condition, timeout) \
405 __ret = __wait_event_hrtimeout(wq, condition, timeout, \
406 TASK_UNINTERRUPTIBLE); \
411 * wait_event_interruptible_hrtimeout - sleep until a condition gets true or a timeout elapses
412 * @wq: the waitqueue to wait on
413 * @condition: a C expression for the event to wait for
414 * @timeout: timeout, as a ktime_t
416 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
417 * @condition evaluates to true or a signal is received.
418 * The @condition is checked each time the waitqueue @wq is woken up.
420 * wake_up() has to be called after changing any variable that could
421 * change the result of the wait condition.
423 * The function returns 0 if @condition became true, -ERESTARTSYS if it was
424 * interrupted by a signal, or -ETIME if the timeout elapsed.
426 #define wait_event_interruptible_hrtimeout(wq, condition, timeout) \
430 __ret = __wait_event_hrtimeout(wq, condition, timeout, \
431 TASK_INTERRUPTIBLE); \
435 #define __wait_event_interruptible_exclusive(wq, condition, ret) \
438 DEFINE_WAIT(__wait); \
441 prepare_to_wait_exclusive(&wq, &__wait, \
442 TASK_INTERRUPTIBLE); \
445 if (signal_pending(current)) { \
446 ret = -ERESTARTSYS; \
447 abort_exclusive_wait(&wq, &__wait, \
448 TASK_INTERRUPTIBLE, NULL); \
453 finish_wait(&wq, &__wait); \
457 #define wait_event_interruptible_exclusive(wq, condition) \
461 __wait_event_interruptible_exclusive(wq, condition, __ret);\
466 #define __wait_event_interruptible_locked(wq, condition, exclusive, irq) \
469 DEFINE_WAIT(__wait); \
471 __wait.flags |= WQ_FLAG_EXCLUSIVE; \
473 if (likely(list_empty(&__wait.task_list))) \
474 __add_wait_queue_tail(&(wq), &__wait); \
475 set_current_state(TASK_INTERRUPTIBLE); \
476 if (signal_pending(current)) { \
477 __ret = -ERESTARTSYS; \
481 spin_unlock_irq(&(wq).lock); \
483 spin_unlock(&(wq).lock); \
486 spin_lock_irq(&(wq).lock); \
488 spin_lock(&(wq).lock); \
489 } while (!(condition)); \
490 __remove_wait_queue(&(wq), &__wait); \
491 __set_current_state(TASK_RUNNING); \
497 * wait_event_interruptible_locked - sleep until a condition gets true
498 * @wq: the waitqueue to wait on
499 * @condition: a C expression for the event to wait for
501 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
502 * @condition evaluates to true or a signal is received.
503 * The @condition is checked each time the waitqueue @wq is woken up.
505 * It must be called with wq.lock being held. This spinlock is
506 * unlocked while sleeping but @condition testing is done while lock
507 * is held and when this macro exits the lock is held.
509 * The lock is locked/unlocked using spin_lock()/spin_unlock()
510 * functions which must match the way they are locked/unlocked outside
513 * wake_up_locked() has to be called after changing any variable that could
514 * change the result of the wait condition.
516 * The function will return -ERESTARTSYS if it was interrupted by a
517 * signal and 0 if @condition evaluated to true.
519 #define wait_event_interruptible_locked(wq, condition) \
521 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, 0))
524 * wait_event_interruptible_locked_irq - sleep until a condition gets true
525 * @wq: the waitqueue to wait on
526 * @condition: a C expression for the event to wait for
528 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
529 * @condition evaluates to true or a signal is received.
530 * The @condition is checked each time the waitqueue @wq is woken up.
532 * It must be called with wq.lock being held. This spinlock is
533 * unlocked while sleeping but @condition testing is done while lock
534 * is held and when this macro exits the lock is held.
536 * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
537 * functions which must match the way they are locked/unlocked outside
540 * wake_up_locked() has to be called after changing any variable that could
541 * change the result of the wait condition.
543 * The function will return -ERESTARTSYS if it was interrupted by a
544 * signal and 0 if @condition evaluated to true.
546 #define wait_event_interruptible_locked_irq(wq, condition) \
548 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, 1))
551 * wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true
552 * @wq: the waitqueue to wait on
553 * @condition: a C expression for the event to wait for
555 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
556 * @condition evaluates to true or a signal is received.
557 * The @condition is checked each time the waitqueue @wq is woken up.
559 * It must be called with wq.lock being held. This spinlock is
560 * unlocked while sleeping but @condition testing is done while lock
561 * is held and when this macro exits the lock is held.
563 * The lock is locked/unlocked using spin_lock()/spin_unlock()
564 * functions which must match the way they are locked/unlocked outside
567 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
568 * set thus when other process waits process on the list if this
569 * process is awaken further processes are not considered.
571 * wake_up_locked() has to be called after changing any variable that could
572 * change the result of the wait condition.
574 * The function will return -ERESTARTSYS if it was interrupted by a
575 * signal and 0 if @condition evaluated to true.
577 #define wait_event_interruptible_exclusive_locked(wq, condition) \
579 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 0))
582 * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true
583 * @wq: the waitqueue to wait on
584 * @condition: a C expression for the event to wait for
586 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
587 * @condition evaluates to true or a signal is received.
588 * The @condition is checked each time the waitqueue @wq is woken up.
590 * It must be called with wq.lock being held. This spinlock is
591 * unlocked while sleeping but @condition testing is done while lock
592 * is held and when this macro exits the lock is held.
594 * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
595 * functions which must match the way they are locked/unlocked outside
598 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
599 * set thus when other process waits process on the list if this
600 * process is awaken further processes are not considered.
602 * wake_up_locked() has to be called after changing any variable that could
603 * change the result of the wait condition.
605 * The function will return -ERESTARTSYS if it was interrupted by a
606 * signal and 0 if @condition evaluated to true.
608 #define wait_event_interruptible_exclusive_locked_irq(wq, condition) \
610 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 1))
614 #define __wait_event_killable(wq, condition, ret) \
616 DEFINE_WAIT(__wait); \
619 prepare_to_wait(&wq, &__wait, TASK_KILLABLE); \
622 if (!fatal_signal_pending(current)) { \
626 ret = -ERESTARTSYS; \
629 finish_wait(&wq, &__wait); \
633 * wait_event_killable - sleep until a condition gets true
634 * @wq: the waitqueue to wait on
635 * @condition: a C expression for the event to wait for
637 * The process is put to sleep (TASK_KILLABLE) until the
638 * @condition evaluates to true or a signal is received.
639 * The @condition is checked each time the waitqueue @wq is woken up.
641 * wake_up() has to be called after changing any variable that could
642 * change the result of the wait condition.
644 * The function will return -ERESTARTSYS if it was interrupted by a
645 * signal and 0 if @condition evaluated to true.
647 #define wait_event_killable(wq, condition) \
651 __wait_event_killable(wq, condition, __ret); \
656 #define __wait_event_lock_irq(wq, condition, lock, cmd) \
658 DEFINE_WAIT(__wait); \
661 prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
664 spin_unlock_irq(&lock); \
667 spin_lock_irq(&lock); \
669 finish_wait(&wq, &__wait); \
673 * wait_event_lock_irq_cmd - sleep until a condition gets true. The
674 * condition is checked under the lock. This
675 * is expected to be called with the lock
677 * @wq: the waitqueue to wait on
678 * @condition: a C expression for the event to wait for
679 * @lock: a locked spinlock_t, which will be released before cmd
680 * and schedule() and reacquired afterwards.
681 * @cmd: a command which is invoked outside the critical section before
684 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
685 * @condition evaluates to true. The @condition is checked each time
686 * the waitqueue @wq is woken up.
688 * wake_up() has to be called after changing any variable that could
689 * change the result of the wait condition.
691 * This is supposed to be called while holding the lock. The lock is
692 * dropped before invoking the cmd and going to sleep and is reacquired
695 #define wait_event_lock_irq_cmd(wq, condition, lock, cmd) \
699 __wait_event_lock_irq(wq, condition, lock, cmd); \
703 * wait_event_lock_irq - sleep until a condition gets true. The
704 * condition is checked under the lock. This
705 * is expected to be called with the lock
707 * @wq: the waitqueue to wait on
708 * @condition: a C expression for the event to wait for
709 * @lock: a locked spinlock_t, which will be released before schedule()
710 * and reacquired afterwards.
712 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
713 * @condition evaluates to true. The @condition is checked each time
714 * the waitqueue @wq is woken up.
716 * wake_up() has to be called after changing any variable that could
717 * change the result of the wait condition.
719 * This is supposed to be called while holding the lock. The lock is
720 * dropped before going to sleep and is reacquired afterwards.
722 #define wait_event_lock_irq(wq, condition, lock) \
726 __wait_event_lock_irq(wq, condition, lock, ); \
730 #define __wait_event_interruptible_lock_irq(wq, condition, \
733 DEFINE_WAIT(__wait); \
736 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
739 if (signal_pending(current)) { \
740 ret = -ERESTARTSYS; \
743 spin_unlock_irq(&lock); \
746 spin_lock_irq(&lock); \
748 finish_wait(&wq, &__wait); \
752 * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true.
753 * The condition is checked under the lock. This is expected to
754 * be called with the lock taken.
755 * @wq: the waitqueue to wait on
756 * @condition: a C expression for the event to wait for
757 * @lock: a locked spinlock_t, which will be released before cmd and
758 * schedule() and reacquired afterwards.
759 * @cmd: a command which is invoked outside the critical section before
762 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
763 * @condition evaluates to true or a signal is received. The @condition is
764 * checked each time the waitqueue @wq is woken up.
766 * wake_up() has to be called after changing any variable that could
767 * change the result of the wait condition.
769 * This is supposed to be called while holding the lock. The lock is
770 * dropped before invoking the cmd and going to sleep and is reacquired
773 * The macro will return -ERESTARTSYS if it was interrupted by a signal
774 * and 0 if @condition evaluated to true.
776 #define wait_event_interruptible_lock_irq_cmd(wq, condition, lock, cmd) \
781 __wait_event_interruptible_lock_irq(wq, condition, \
787 * wait_event_interruptible_lock_irq - sleep until a condition gets true.
788 * The condition is checked under the lock. This is expected
789 * to be called with the lock taken.
790 * @wq: the waitqueue to wait on
791 * @condition: a C expression for the event to wait for
792 * @lock: a locked spinlock_t, which will be released before schedule()
793 * and reacquired afterwards.
795 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
796 * @condition evaluates to true or signal is received. The @condition is
797 * checked each time the waitqueue @wq is woken up.
799 * wake_up() has to be called after changing any variable that could
800 * change the result of the wait condition.
802 * This is supposed to be called while holding the lock. The lock is
803 * dropped before going to sleep and is reacquired afterwards.
805 * The macro will return -ERESTARTSYS if it was interrupted by a signal
806 * and 0 if @condition evaluated to true.
808 #define wait_event_interruptible_lock_irq(wq, condition, lock) \
813 __wait_event_interruptible_lock_irq(wq, condition, \
818 #define __wait_event_interruptible_lock_irq_timeout(wq, condition, \
821 DEFINE_WAIT(__wait); \
824 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
825 if (___wait_cond_timeout(condition, ret)) \
827 if (signal_pending(current)) { \
828 ret = -ERESTARTSYS; \
831 spin_unlock_irq(&lock); \
832 ret = schedule_timeout(ret); \
833 spin_lock_irq(&lock); \
835 finish_wait(&wq, &__wait); \
839 * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets true or a timeout elapses.
840 * The condition is checked under the lock. This is expected
841 * to be called with the lock taken.
842 * @wq: the waitqueue to wait on
843 * @condition: a C expression for the event to wait for
844 * @lock: a locked spinlock_t, which will be released before schedule()
845 * and reacquired afterwards.
846 * @timeout: timeout, in jiffies
848 * The process is put to sleep (TASK_INTERRUPTIBLE) until the
849 * @condition evaluates to true or signal is received. The @condition is
850 * checked each time the waitqueue @wq is woken up.
852 * wake_up() has to be called after changing any variable that could
853 * change the result of the wait condition.
855 * This is supposed to be called while holding the lock. The lock is
856 * dropped before going to sleep and is reacquired afterwards.
858 * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
859 * was interrupted by a signal, and the remaining jiffies otherwise
860 * if the condition evaluated to true before the timeout elapsed.
862 #define wait_event_interruptible_lock_irq_timeout(wq, condition, lock, \
865 int __ret = timeout; \
868 __wait_event_interruptible_lock_irq_timeout( \
869 wq, condition, lock, __ret); \
875 * These are the old interfaces to sleep waiting for an event.
876 * They are racy. DO NOT use them, use the wait_event* interfaces above.
877 * We plan to remove these interfaces.
879 extern void sleep_on(wait_queue_head_t *q);
880 extern long sleep_on_timeout(wait_queue_head_t *q,
881 signed long timeout);
882 extern void interruptible_sleep_on(wait_queue_head_t *q);
883 extern long interruptible_sleep_on_timeout(wait_queue_head_t *q,
884 signed long timeout);
887 * Waitqueues which are removed from the waitqueue_head at wakeup time
889 void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state);
890 void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state);
891 void finish_wait(wait_queue_head_t *q, wait_queue_t *wait);
892 void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait,
893 unsigned int mode, void *key);
894 int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
895 int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
897 #define DEFINE_WAIT_FUNC(name, function) \
898 wait_queue_t name = { \
899 .private = current, \
901 .task_list = LIST_HEAD_INIT((name).task_list), \
904 #define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function)
906 #define DEFINE_WAIT_BIT(name, word, bit) \
907 struct wait_bit_queue name = { \
908 .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \
910 .private = current, \
911 .func = wake_bit_function, \
913 LIST_HEAD_INIT((name).wait.task_list), \
917 #define init_wait(wait) \
919 (wait)->private = current; \
920 (wait)->func = autoremove_wake_function; \
921 INIT_LIST_HEAD(&(wait)->task_list); \
926 * wait_on_bit - wait for a bit to be cleared
927 * @word: the word being waited on, a kernel virtual address
928 * @bit: the bit of the word being waited on
929 * @action: the function used to sleep, which may take special actions
930 * @mode: the task state to sleep in
932 * There is a standard hashed waitqueue table for generic use. This
933 * is the part of the hashtable's accessor API that waits on a bit.
934 * For instance, if one were to have waiters on a bitflag, one would
935 * call wait_on_bit() in threads waiting for the bit to clear.
936 * One uses wait_on_bit() where one is waiting for the bit to clear,
937 * but has no intention of setting it.
939 static inline int wait_on_bit(void *word, int bit,
940 int (*action)(void *), unsigned mode)
942 if (!test_bit(bit, word))
944 return out_of_line_wait_on_bit(word, bit, action, mode);
948 * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
949 * @word: the word being waited on, a kernel virtual address
950 * @bit: the bit of the word being waited on
951 * @action: the function used to sleep, which may take special actions
952 * @mode: the task state to sleep in
954 * There is a standard hashed waitqueue table for generic use. This
955 * is the part of the hashtable's accessor API that waits on a bit
956 * when one intends to set it, for instance, trying to lock bitflags.
957 * For instance, if one were to have waiters trying to set bitflag
958 * and waiting for it to clear before setting it, one would call
959 * wait_on_bit() in threads waiting to be able to set the bit.
960 * One uses wait_on_bit_lock() where one is waiting for the bit to
961 * clear with the intention of setting it, and when done, clearing it.
963 static inline int wait_on_bit_lock(void *word, int bit,
964 int (*action)(void *), unsigned mode)
966 if (!test_and_set_bit(bit, word))
968 return out_of_line_wait_on_bit_lock(word, bit, action, mode);
972 * wait_on_atomic_t - Wait for an atomic_t to become 0
973 * @val: The atomic value being waited on, a kernel virtual address
974 * @action: the function used to sleep, which may take special actions
975 * @mode: the task state to sleep in
977 * Wait for an atomic_t to become 0. We abuse the bit-wait waitqueue table for
978 * the purpose of getting a waitqueue, but we set the key to a bit number
979 * outside of the target 'word'.
982 int wait_on_atomic_t(atomic_t *val, int (*action)(atomic_t *), unsigned mode)
984 if (atomic_read(val) == 0)
986 return out_of_line_wait_on_atomic_t(val, action, mode);