hrtimer: add a hrtimer_start_range() function

this patch adds a _range version of hrtimer_start() so that range timers
can be created; the hrtimer_start() function is just a wrapper around this.

In addition, hrtimer_start_expires() will now preserve existing ranges.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 4c1a834b9849..1c0473e8ecb4 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -350,13 +350,20 @@ static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { }
 /* Basic timer operations: */
 extern int hrtimer_start(struct hrtimer *timer, ktime_t tim,
 			 const enum hrtimer_mode mode);
+extern int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
+			unsigned long range_ns, const enum hrtimer_mode mode);
 extern int hrtimer_cancel(struct hrtimer *timer);
 extern int hrtimer_try_to_cancel(struct hrtimer *timer);
 
 static inline int hrtimer_start_expires(struct hrtimer *timer,
 						enum hrtimer_mode mode)
 {
-	return hrtimer_start(timer, hrtimer_get_expires(timer), mode);
+	unsigned long delta;
+	ktime_t soft, hard;
+	soft = hrtimer_get_softexpires(timer);
+	hard = hrtimer_get_expires(timer);
+	delta = ktime_to_ns(ktime_sub(hard, soft));
+	return hrtimer_start_range_ns(timer, hrtimer_get_expires(timer), delta, mode);
 }
 
 static inline int hrtimer_restart(struct hrtimer *timer)