1 // SPDX-License-Identifier: GPL-2.0
4  * Generic wait-for-completion handler;
7  * wait_for_completion default blocks whereas semaphore default non-block. The
17  * complete: - signals a single thread waiting on this completion
18  * @x:  holds the state of this particular completion
26  * accessing the task state.
32 	raw_spin_lock_irqsave(&x->wait.lock, flags);  in complete()
34 	if (x->done != UINT_MAX)  in complete()
35 		x->done++;  in complete()
36 	swake_up_locked(&x->wait);  in complete()
37 	raw_spin_unlock_irqrestore(&x->wait.lock, flags);  in complete()
42  * complete_all: - signals all threads waiting on this completion
43  * @x:  holds the state of this particular completion
48  * accessing the task state.
63 	raw_spin_lock_irqsave(&x->wait.lock, flags);  in complete_all()
64 	x->done = UINT_MAX;  in complete_all()
65 	swake_up_all_locked(&x->wait);  in complete_all()
66 	raw_spin_unlock_irqrestore(&x->wait.lock, flags);  in complete_all()
72 		   long (*action)(long), long timeout, int state)  in do_wait_for_common()  argument
74 	if (!x->done) {  in do_wait_for_common()
75 		DECLARE_SWAITQUEUE(wait);  in do_wait_for_common()
78 			if (signal_pending_state(state, current)) {  in do_wait_for_common()
79 				timeout = -ERESTARTSYS;  in do_wait_for_common()
82 			__prepare_to_swait(&x->wait, &wait);  in do_wait_for_common()
83 			__set_current_state(state);  in do_wait_for_common()
84 			raw_spin_unlock_irq(&x->wait.lock);  in do_wait_for_common()
86 			raw_spin_lock_irq(&x->wait.lock);  in do_wait_for_common()
87 		} while (!x->done && timeout);  in do_wait_for_common()
88 		__finish_swait(&x->wait, &wait);  in do_wait_for_common()
89 		if (!x->done)  in do_wait_for_common()
92 	if (x->done != UINT_MAX)  in do_wait_for_common()
93 		x->done--;  in do_wait_for_common()
99 		  long (*action)(long), long timeout, int state)  in __wait_for_common()  argument
105 	raw_spin_lock_irq(&x->wait.lock);  in __wait_for_common()
106 	timeout = do_wait_for_common(x, action, timeout, state);  in __wait_for_common()
107 	raw_spin_unlock_irq(&x->wait.lock);  in __wait_for_common()
115 wait_for_common(struct completion *x, long timeout, int state)  in wait_for_common()  argument
117 	return __wait_for_common(x, schedule_timeout, timeout, state);  in wait_for_common()
121 wait_for_common_io(struct completion *x, long timeout, int state)  in wait_for_common_io()  argument
123 	return __wait_for_common(x, io_schedule_timeout, timeout, state);  in wait_for_common_io()
127  * wait_for_completion: - waits for completion of a task
128  * @x:  holds the state of this particular completion
143  * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
144  * @x:  holds the state of this particular completion
162  * wait_for_completion_io: - waits for completion of a task
163  * @x:  holds the state of this particular completion
176  * wait_for_completion_io_timeout: - waits for completion of a task (w/timeout)
177  * @x:  holds the state of this particular completion
196  * wait_for_completion_interruptible: - waits for completion of a task (w/intr)
197  * @x:  holds the state of this particular completion
202  * Return: -ERESTARTSYS if interrupted, 0 if completed.
208 	if (t == -ERESTARTSYS)  in wait_for_completion_interruptible()
215  * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
216  * @x:  holds the state of this particular completion
222  * Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1,
234  * wait_for_completion_killable: - waits for completion of a task (killable)
235  * @x:  holds the state of this particular completion
240  * Return: -ERESTARTSYS if interrupted, 0 if completed.
246 	if (t == -ERESTARTSYS)  in wait_for_completion_killable()
252 int __sched wait_for_completion_state(struct completion *x, unsigned int state)  in wait_for_completion_state()  argument
254 	long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, state);  in wait_for_completion_state()
256 	if (t == -ERESTARTSYS)  in wait_for_completion_state()
263  * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable))
264  * @x:  holds the state of this particular completion
271  * Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1,
283  *	try_wait_for_completion - try to decrement a completion without blocking
300 	 * Since x->done will need to be locked only  in try_wait_for_completion()
301 	 * in the non-blocking case, we check x->done  in try_wait_for_completion()
305 	if (!READ_ONCE(x->done))  in try_wait_for_completion()
308 	raw_spin_lock_irqsave(&x->wait.lock, flags);  in try_wait_for_completion()
309 	if (!x->done)  in try_wait_for_completion()
311 	else if (x->done != UINT_MAX)  in try_wait_for_completion()
312 		x->done--;  in try_wait_for_completion()
313 	raw_spin_unlock_irqrestore(&x->wait.lock, flags);  in try_wait_for_completion()
319  *	completion_done - Test to see if a completion has any waiters
331 	if (!READ_ONCE(x->done))  in completion_done()
335 	 * If ->done, we need to wait for complete() to release ->wait.lock  in completion_done()
339 	raw_spin_lock_irqsave(&x->wait.lock, flags);  in completion_done()
340 	raw_spin_unlock_irqrestore(&x->wait.lock, flags);  in completion_done()