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>
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 4c1a834..1c0473e 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -350,13 +350,20 @@
/* 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)
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 0148300..a022209 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -945,9 +945,10 @@
}
/**
- * hrtimer_start - (re)start an relative timer on the current CPU
+ * hrtimer_start_range_ns - (re)start an relative timer on the current CPU
* @timer: the timer to be added
* @tim: expiry time
+ * @delta_ns: "slack" range for the timer
* @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)
*
* Returns:
@@ -955,7 +956,8 @@
* 1 when the timer was active
*/
int
-hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
+hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, unsigned long delta_ns,
+ const enum hrtimer_mode mode)
{
struct hrtimer_clock_base *base, *new_base;
unsigned long flags;
@@ -983,7 +985,7 @@
#endif
}
- hrtimer_set_expires(timer, tim);
+ hrtimer_set_expires_range_ns(timer, tim, delta_ns);
timer_stats_hrtimer_set_start_info(timer);
@@ -1016,8 +1018,26 @@
return ret;
}
+EXPORT_SYMBOL_GPL(hrtimer_start_range_ns);
+
+/**
+ * hrtimer_start - (re)start an relative timer on the current CPU
+ * @timer: the timer to be added
+ * @tim: expiry time
+ * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)
+ *
+ * Returns:
+ * 0 on success
+ * 1 when the timer was active
+ */
+int
+hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
+{
+ return hrtimer_start_range_ns(timer, tim, 0, mode);
+}
EXPORT_SYMBOL_GPL(hrtimer_start);
+
/**
* hrtimer_try_to_cancel - try to deactivate a timer
* @timer: hrtimer to stop