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>
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index f11d83b..3e5cba2 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -199,6 +199,12 @@
}
+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 @@
}
/**
- * 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 @@
}
/**
+ * 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 @@
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);
+}