kernel/time/alarmtimer.c

6  * but triggers a RTC alarm if the box is suspend.
61 /* rtc timer and device for setting alarm wakeups at suspend */
151  * alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue
153  * @alarm: pointer to alarm being enqueued.
155  * Adds alarm to a alarm_base timerqueue
159 static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm)
161 	if (alarm->state & ALARMTIMER_STATE_ENQUEUED)
162 		timerqueue_del(&base->timerqueue, &alarm->node);
164 	timerqueue_add(&base->timerqueue, &alarm->node);
165 	alarm->state |= ALARMTIMER_STATE_ENQUEUED;
169  * alarmtimer_dequeue - Removes an alarm timer from an alarm_base timerqueue
171  * @alarm: pointer to alarm being removed
173  * Removes alarm to a alarm_base timerqueue
177 static void alarmtimer_dequeue(struct alarm_base *base, struct alarm *alarm)
179 	if (!(alarm->state & ALARMTIMER_STATE_ENQUEUED))
182 	timerqueue_del(&base->timerqueue, &alarm->node);
183 	alarm->state &= ~ALARMTIMER_STATE_ENQUEUED;
188  * alarmtimer_fired - Handles alarm hrtimer being fired.
191  * When a alarm timer fires, this runs through the timerqueue to
192  * see which alarms expired, and runs those. If there are more alarm
194  * the next future alarm timer expires.
198 	struct alarm *alarm = container_of(timer, struct alarm, timer);
199 	struct alarm_base *base = &alarm_bases[alarm->type];
205 	alarmtimer_dequeue(base, alarm);
208 	if (alarm->function)
209 		restart = alarm->function(alarm, base->get_ktime());
213 		hrtimer_set_expires(&alarm->timer, alarm->node.expires);
214 		alarmtimer_enqueue(base, alarm);
219 	trace_alarmtimer_fired(alarm, base->get_ktime());
224 ktime_t alarm_expires_remaining(const struct alarm *alarm)
226 	struct alarm_base *base = &alarm_bases[alarm->type];
227 	return ktime_sub(alarm->node.expires, base->get_ktime());
295 	 * If the RTC alarm timer only supports a limited time offset, set the
296 	 * alarm time to the maximum supported value.
306 	/* Set alarm, if in the past reject suspend briefly to handle */
336 __alarm_init(struct alarm *alarm, enum alarmtimer_type type,
337 	     enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
339 	timerqueue_init(&alarm->node);
340 	alarm->timer.function = alarmtimer_fired;
341 	alarm->function = function;
342 	alarm->type = type;
343 	alarm->state = ALARMTIMER_STATE_INACTIVE;
347  * alarm_init - Initialize an alarm structure
348  * @alarm: ptr to alarm to be initialized
349  * @type: the type of the alarm
350  * @function: callback that is run when the alarm fires
352 void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
353 		enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
355 	hrtimer_init(&alarm->timer, alarm_bases[type].base_clockid,
357 	__alarm_init(alarm, type, function);
362  * alarm_start - Sets an absolute alarm to fire
363  * @alarm: ptr to alarm to set
364  * @start: time to run the alarm
366 void alarm_start(struct alarm *alarm, ktime_t start)
368 	struct alarm_base *base = &alarm_bases[alarm->type];
372 	alarm->node.expires = start;
373 	alarmtimer_enqueue(base, alarm);
374 	hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS);
377 	trace_alarmtimer_start(alarm, base->get_ktime());
382  * alarm_start_relative - Sets a relative alarm to fire
383  * @alarm: ptr to alarm to set
384  * @start: time relative to now to run the alarm
386 void alarm_start_relative(struct alarm *alarm, ktime_t start)
388 	struct alarm_base *base = &alarm_bases[alarm->type];
391 	alarm_start(alarm, start);
395 void alarm_restart(struct alarm *alarm)
397 	struct alarm_base *base = &alarm_bases[alarm->type];
401 	hrtimer_set_expires(&alarm->timer, alarm->node.expires);
402 	hrtimer_restart(&alarm->timer);
403 	alarmtimer_enqueue(base, alarm);
409  * alarm_try_to_cancel - Tries to cancel an alarm timer
410  * @alarm: ptr to alarm to be canceled
415 int alarm_try_to_cancel(struct alarm *alarm)
417 	struct alarm_base *base = &alarm_bases[alarm->type];
422 	ret = hrtimer_try_to_cancel(&alarm->timer);
424 		alarmtimer_dequeue(base, alarm);
427 	trace_alarmtimer_cancel(alarm, base->get_ktime());
434  * alarm_cancel - Spins trying to cancel an alarm timer until it is done
435  * @alarm: ptr to alarm to be canceled
439 int alarm_cancel(struct alarm *alarm)
442 		int ret = alarm_try_to_cancel(alarm);
445 		hrtimer_cancel_wait_running(&alarm->timer);
451 u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval)
456 	delta = ktime_sub(now, alarm->node.expires);
466 		alarm->node.expires = ktime_add_ns(alarm->node.expires,
469 		if (alarm->node.expires > now)
478 	alarm->node.expires = ktime_add_safe(alarm->node.expires, interval);
483 static u64 __alarm_forward_now(struct alarm *alarm, ktime_t interval, bool throttle)
485 	struct alarm_base *base = &alarm_bases[alarm->type];
506 	return alarm_forward(alarm, now, interval);
509 u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)
511 	return __alarm_forward_now(alarm, interval, false);
533 		WARN_ONCE(1, "Invalid alarm type: %d\n", type);
563  * @alarm: alarm that fired
566  * Posix timer callback for expired alarm timers.
570 static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
573 	struct k_itimer *ptr = container_of(alarm, struct k_itimer,
574 					    it.alarm.alarmtimer);
591 		ptr->it_overrun += __alarm_forward_now(alarm, ptr->it_interval, true);
607 	struct alarm *alarm = &timr->it.alarm.alarmtimer;
609 	timr->it_overrun += alarm_forward_now(alarm, timr->it_interval);
610 	alarm_start(alarm, alarm->node.expires);
620 	struct alarm *alarm = &timr->it.alarm.alarmtimer;
622 	return alarm_forward(alarm, timr->it_interval, now);
632 	struct alarm *alarm = &timr->it.alarm.alarmtimer;
634 	return ktime_sub(alarm->node.expires, now);
643 	return alarm_try_to_cancel(&timr->it.alarm.alarmtimer);
656 	hrtimer_cancel_wait_running(&timr->it.alarm.alarmtimer.timer);
669 	struct alarm *alarm = &timr->it.alarm.alarmtimer;
670 	struct alarm_base *base = &alarm_bases[alarm->type];
675 		alarm->node.expires = expires;
677 		alarm_start(&timr->it.alarm.alarmtimer, expires);
685  * Returns the granularity of underlying alarm base clock
702  * Provides the underlying alarm base time in a tasks time namespace.
720  * Provides the underlying alarm base time in the root namespace.
749 	alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer);
755  * @alarm: ptr to alarm that fired
762 static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm,
765 	struct task_struct *task = alarm->data;
767 	alarm->data = NULL;
775  * @alarm: ptr to alarmtimer
777  * @type: alarm type (BOOTTIME/REALTIME).
779  * Sets the alarm timer and sleeps until it is fired or interrupted.
781 static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp,
785 	alarm->data = (void *)current;
788 		alarm_start(alarm, absexp);
789 		if (likely(alarm->data))
792 		alarm_cancel(alarm);
793 	} while (alarm->data && !signal_pending(current));
797 	destroy_hrtimer_on_stack(&alarm->timer);
799 	if (!alarm->data)
821 alarm_init_on_stack(struct alarm *alarm, enum alarmtimer_type type,
822 		    enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
824 	hrtimer_init_on_stack(&alarm->timer, alarm_bases[type].base_clockid,
826 	__alarm_init(alarm, type, function);
839 	struct alarm alarm;
841 	alarm_init_on_stack(&alarm, type, alarmtimer_nsleep_wakeup);
843 	return alarmtimer_do_nsleep(&alarm, exp, type);
859 	struct alarm alarm;
872 	alarm_init_on_stack(&alarm, type, alarmtimer_nsleep_wakeup);
884 	ret = alarmtimer_do_nsleep(&alarm, exp, type);
937  * alarmtimer_init - Initialize alarm timer code
939  * This function initializes the alarm bases and registers
949 	/* Initialize alarm bases */