1 files changed, 26 insertions, 0 deletions

diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 48167a6ae55c..c35d449be031 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -34,6 +34,16 @@ ktime_t tick_period;
 static int tick_do_timer_cpu = -1;
 DEFINE_SPINLOCK(tick_device_lock);
 
+/**
+ * tick_is_oneshot_available - check for a oneshot capable event device
+ */
+int tick_is_oneshot_available(void)
+{
+        struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
+
+        return dev && (dev->features & CLOCK_EVT_FEAT_ONESHOT);
+}
+
 /*
  * Periodic tick
  */
@@ -162,6 +172,8 @@ static void tick_setup_device(struct tick_device *td,
 
         if (td->mode == TICKDEV_MODE_PERIODIC)
                 tick_setup_periodic(newdev, 0);
+        else
+                tick_setup_oneshot(newdev, handler, next_event);
 }
 
 /*
@@ -209,6 +221,12 @@ static int tick_check_new_device(struct clock_event_device *newdev)
          */
         if (curdev) {
                 /*
+                 * Prefer one shot capable devices !
+                 */
+                if ((curdev->features & CLOCK_EVT_FEAT_ONESHOT) &&
+                    !(newdev->features & CLOCK_EVT_FEAT_ONESHOT))
+                        goto out_bc;
+                /*
                  * Check the rating
                  */
                 if (curdev->rating >= newdev->rating)
@@ -226,6 +244,8 @@ static int tick_check_new_device(struct clock_event_device *newdev)
         }
         clockevents_exchange_device(curdev, newdev);
         tick_setup_device(td, newdev, cpu, cpumask);
+        if (newdev->features & CLOCK_EVT_FEAT_ONESHOT)
+                tick_oneshot_notify();
 
         spin_unlock_irqrestore(&tick_device_lock, flags);
         return NOTIFY_STOP;
@@ -285,7 +305,13 @@ static int tick_notify(struct notifier_block *nb, unsigned long reason,
                 tick_broadcast_on_off(reason, dev);
                 break;
 
+        case CLOCK_EVT_NOTIFY_BROADCAST_ENTER:
+        case CLOCK_EVT_NOTIFY_BROADCAST_EXIT:
+                tick_broadcast_oneshot_control(reason);
+                break;
+
         case CLOCK_EVT_NOTIFY_CPU_DEAD:
+                tick_shutdown_broadcast_oneshot(dev);
                 tick_shutdown_broadcast(dev);
                 tick_shutdown(dev);
                 break;