[PATCH] tick-management: dyntick / highres functionality

[deliverable/linux.git] / kernel / time / tick-common.c

diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 48167a6ae55c7e24b8dbadd7d35c3dc34410f41f..c35d449be031ae84de018564a9296d0bb60dccf1 100644 (file)
--- 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);
 }
 
 /*
@@ -208,6 +220,12 @@ static int tick_check_new_device(struct clock_event_device *newdev)
         * feature.
         */
        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
                 */
@@ -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;