Commit 6cffe00f authored by Todd Poynor's avatar Todd Poynor Committed by John Stultz
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alarmtimer: Add functions for timerfd support 



Add functions needed for hooking up alarmtimer to timerfd:

* alarm_restart: Similar to hrtimer_restart, restart an alarmtimer after
  the expires time has already been updated (as with alarm_forward).

* alarm_forward_now: Similar to hrtimer_forward_now, move the expires
  time forward to an interval from the current time of the associated clock.

* alarm_start_relative: Start an alarmtimer with an expires time relative to
  the current time of the associated clock.

* alarm_expires_remaining: Similar to hrtimer_expires_remaining, return the
  amount of time remaining until alarm expiry.

Signed-off-by: default avatarTodd Poynor <toddpoynor@google.com>
Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
parent 3565184e

include/linux/alarmtimer.h

+4 −0
Original line number Diff line number Diff line
@@ -44,10 +44,14 @@ struct alarm { 
void alarm_init(struct alarm *alarm, enum alarmtimer_type type,

		enum alarmtimer_restart (*function)(struct alarm *, ktime_t));

int alarm_start(struct alarm *alarm, ktime_t start);

int alarm_start_relative(struct alarm *alarm, ktime_t start);

void alarm_restart(struct alarm *alarm);

int alarm_try_to_cancel(struct alarm *alarm);

int alarm_cancel(struct alarm *alarm);



u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval);

u64 alarm_forward_now(struct alarm *alarm, ktime_t interval);

ktime_t alarm_expires_remaining(const struct alarm *alarm);



/* Provide way to access the rtc device being used by alarmtimers */

struct rtc_device *alarmtimer_get_rtcdev(void);

kernel/time/alarmtimer.c

+38 −1
Original line number Diff line number Diff line
@@ -199,6 +199,12 @@ static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer) 


}



ktime_t alarm_expires_remaining(const struct alarm *alarm)

{

	struct alarm_base *base = &alarm_bases[alarm->type];

	return ktime_sub(alarm->node.expires, base->gettime());

}



#ifdef CONFIG_RTC_CLASS

/**

 * alarmtimer_suspend - Suspend time callback
@@ -305,7 +311,7 @@ void alarm_init(struct alarm *alarm, enum alarmtimer_type type, 
}



/**

 * alarm_start - Sets an alarm to fire

 * alarm_start - Sets an absolute alarm to fire

 * @alarm: ptr to alarm to set

 * @start: time to run the alarm

 */
@@ -324,6 +330,31 @@ int alarm_start(struct alarm *alarm, ktime_t start) 
	return ret;

}



/**

 * alarm_start_relative - Sets a relative alarm to fire

 * @alarm: ptr to alarm to set

 * @start: time relative to now to run the alarm

 */

int alarm_start_relative(struct alarm *alarm, ktime_t start)

{

	struct alarm_base *base = &alarm_bases[alarm->type];



	start = ktime_add(start, base->gettime());

	return alarm_start(alarm, start);

}



void alarm_restart(struct alarm *alarm)

{

	struct alarm_base *base = &alarm_bases[alarm->type];

	unsigned long flags;



	spin_lock_irqsave(&base->lock, flags);

	hrtimer_set_expires(&alarm->timer, alarm->node.expires);

	hrtimer_restart(&alarm->timer);

	alarmtimer_enqueue(base, alarm);

	spin_unlock_irqrestore(&base->lock, flags);

}



/**

 * alarm_try_to_cancel - Tries to cancel an alarm timer

 * @alarm: ptr to alarm to be canceled
@@ -394,6 +425,12 @@ u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval) 
	return overrun;

}



u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)

{

	struct alarm_base *base = &alarm_bases[alarm->type];



	return alarm_forward(alarm, base->gettime(), interval);

}

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