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authorTodd Poynor <toddpoynor@google.com>2013-05-15 14:38:11 -0700
committerJohn Stultz <john.stultz@linaro.org>2013-05-29 12:57:34 -0700
commit6cffe00f7d4e24679eae6b7aae4caaf915288256 (patch)
tree3613480b8eefec8b865ba9d3acbb8ecb7ffe4def
parent3565184ed0c1ea46bea5b792da5f72a83c43e49b (diff)
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: Todd Poynor <toddpoynor@google.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
-rw-r--r--include/linux/alarmtimer.h4
-rw-r--r--kernel/time/alarmtimer.c39
2 files changed, 42 insertions, 1 deletions
diff --git a/include/linux/alarmtimer.h b/include/linux/alarmtimer.h
index 9069694e70eb..a899402a5a0e 100644
--- a/include/linux/alarmtimer.h
+++ b/include/linux/alarmtimer.h
@@ -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);
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index f11d83b12949..3e5cba274475 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -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
*/
@@ -325,6 +331,31 @@ int alarm_start(struct alarm *alarm, ktime_t start)
}
/**
+ * 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);
+}