alarmtimers: Add more refined alarm state tracking

In order to allow for functionality like try_to_cancel, add
more refined  state tracking (similar to hrtimers).

CC: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>

1 files changed, 33 insertions, 1 deletions

diff --git a/include/linux/alarmtimer.h b/include/linux/alarmtimer.h
index c854a8e..304124a 100644
--- a/include/linux/alarmtimer.h
+++ b/include/linux/alarmtimer.h
@@ -18,6 +18,11 @@ enum alarmtimer_restart {
 	ALARMTIMER_RESTART,
 };
 
+
+#define ALARMTIMER_STATE_INACTIVE	0x00
+#define ALARMTIMER_STATE_ENQUEUED	0x01
+#define ALARMTIMER_STATE_CALLBACK	0x02
+
 /**
  * struct alarm - Alarm timer structure
  * @node:	timerqueue node for adding to the event list this value
@@ -32,7 +37,7 @@ struct alarm {
 	struct timerqueue_node	node;
 	enum alarmtimer_restart	(*function)(struct alarm *, ktime_t now);
 	enum alarmtimer_type	type;
-	bool			enabled;
+	int			state;
 	void			*data;
 };
 
@@ -43,4 +48,31 @@ void alarm_cancel(struct alarm *alarm);
 
 u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval);
 
+/*
+ * A alarmtimer is active, when it is enqueued into timerqueue or the
+ * callback function is running.
+ */
+static inline int alarmtimer_active(const struct alarm *timer)
+{
+	return timer->state != ALARMTIMER_STATE_INACTIVE;
+}
+
+/*
+ * Helper function to check, whether the timer is on one of the queues
+ */
+static inline int alarmtimer_is_queued(struct alarm *timer)
+{
+	return timer->state & ALARMTIMER_STATE_ENQUEUED;
+}
+
+/*
+ * Helper function to check, whether the timer is running the callback
+ * function
+ */
+static inline int alarmtimer_callback_running(struct alarm *timer)
+{
+	return timer->state & ALARMTIMER_STATE_CALLBACK;
+}
+
+
 #endif