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alarmtimer: Add functions for timerfd support

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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: Todd Poynor <toddpoynor@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
This commit is contained in:
Todd Poynor 2013-05-15 14:38:11 -07:00 committed by John Stultz
parent 3565184ed0
commit 6cffe00f7d
2 changed files with 42 additions and 1 deletions
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4
include/linux/alarmtimer.h
View file

@ -44,10 +44,14 @@ struct alarm {
void alarm_init(struct alarm *alarm, enum alarmtimer_type type, void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
enum alarmtimer_restart (*function)(struct alarm *, ktime_t)); enum alarmtimer_restart (*function)(struct alarm *, ktime_t));
int alarm_start(struct alarm *alarm, ktime_t start); 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_try_to_cancel(struct alarm *alarm);
int alarm_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(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 */ /* Provide way to access the rtc device being used by alarmtimers */
struct rtc_device *alarmtimer_get_rtcdev(void); struct rtc_device *alarmtimer_get_rtcdev(void);

39
kernel/time/alarmtimer.c
View file

@ -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 #ifdef CONFIG_RTC_CLASS
/** /**
* alarmtimer_suspend - Suspend time callback * 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 * @alarm: ptr to alarm to set
* @start: time to run the alarm * @start: time to run the alarm
*/ */
@ -324,6 +330,31 @@ int alarm_start(struct alarm *alarm, ktime_t start)
return ret; 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_try_to_cancel - Tries to cancel an alarm timer
* @alarm: ptr to alarm to be canceled * @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; 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);
}