Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6

[pandora-kernel.git] / kernel / time / tick-broadcast.c

diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 31463d3..f1f3eee 100644 (file)
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -175,6 +175,8 @@ static void tick_do_periodic_broadcast(void)
  */
 static void tick_handle_periodic_broadcast(struct clock_event_device *dev)
 {
+       ktime_t next;
+
        tick_do_periodic_broadcast();
 
        /*
@@ -185,10 +187,13 @@ static void tick_handle_periodic_broadcast(struct clock_event_device *dev)
 
        /*
         * Setup the next period for devices, which do not have
-        * periodic mode:
+        * periodic mode. We read dev->next_event first and add to it
+        * when the event alrady expired. clockevents_program_event()
+        * sets dev->next_event only when the event is really
+        * programmed to the device.
         */
-       for (;;) {
-               ktime_t next = ktime_add(dev->next_event, tick_period);
+       for (next = dev->next_event; ;) {
+               next = ktime_add(next, tick_period);
 
                if (!clockevents_program_event(dev, next, ktime_get()))
                        return;
@@ -205,7 +210,7 @@ static void tick_do_broadcast_on_off(void *why)
        struct clock_event_device *bc, *dev;
        struct tick_device *td;
        unsigned long flags, *reason = why;
-       int cpu;
+       int cpu, bc_stopped;
 
        spin_lock_irqsave(&tick_broadcast_lock, flags);
 
@@ -223,14 +228,15 @@ static void tick_do_broadcast_on_off(void *why)
        if (!tick_device_is_functional(dev))
                goto out;
 
+       bc_stopped = cpus_empty(tick_broadcast_mask);
+
        switch (*reason) {
        case CLOCK_EVT_NOTIFY_BROADCAST_ON:
        case CLOCK_EVT_NOTIFY_BROADCAST_FORCE:
                if (!cpu_isset(cpu, tick_broadcast_mask)) {
                        cpu_set(cpu, tick_broadcast_mask);
                        if (td->mode == TICKDEV_MODE_PERIODIC)
-                               clockevents_set_mode(dev,
-                                                    CLOCK_EVT_MODE_SHUTDOWN);
+                               clockevents_shutdown(dev);
                }
                if (*reason == CLOCK_EVT_NOTIFY_BROADCAST_FORCE)
                        tick_broadcast_force = 1;
@@ -245,9 +251,10 @@ static void tick_do_broadcast_on_off(void *why)
                break;
        }
 
-       if (cpus_empty(tick_broadcast_mask))
-               clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
-       else {
+       if (cpus_empty(tick_broadcast_mask)) {
+               if (!bc_stopped)
+                       clockevents_shutdown(bc);
+       } else if (bc_stopped) {
                if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
                        tick_broadcast_start_periodic(bc);
                else
@@ -298,7 +305,7 @@ void tick_shutdown_broadcast(unsigned int *cpup)
 
        if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) {
                if (bc && cpus_empty(tick_broadcast_mask))
-                       clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
+                       clockevents_shutdown(bc);
        }
 
        spin_unlock_irqrestore(&tick_broadcast_lock, flags);
@@ -313,7 +320,7 @@ void tick_suspend_broadcast(void)
 
        bc = tick_broadcast_device.evtdev;
        if (bc)
-               clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
+               clockevents_shutdown(bc);
 
        spin_unlock_irqrestore(&tick_broadcast_lock, flags);
 }
@@ -364,16 +371,8 @@ cpumask_t *tick_get_broadcast_oneshot_mask(void)
 static int tick_broadcast_set_event(ktime_t expires, int force)
 {
        struct clock_event_device *bc = tick_broadcast_device.evtdev;
-       ktime_t now = ktime_get();
-       int res;
-
-       for(;;) {
-               res = clockevents_program_event(bc, expires, now);
-               if (!res || !force)
-                       return res;
-               now = ktime_get();
-               expires = ktime_add(now, ktime_set(0, bc->min_delta_ns));
-       }
+
+       return tick_dev_program_event(bc, expires, force);
 }
 
 int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
@@ -491,14 +490,52 @@ static void tick_broadcast_clear_oneshot(int cpu)
        cpu_clear(cpu, tick_broadcast_oneshot_mask);
 }
 
+static void tick_broadcast_init_next_event(cpumask_t *mask, ktime_t expires)
+{
+       struct tick_device *td;
+       int cpu;
+
+       for_each_cpu_mask_nr(cpu, *mask) {
+               td = &per_cpu(tick_cpu_device, cpu);
+               if (td->evtdev)
+                       td->evtdev->next_event = expires;
+       }
+}
+
 /**
  * tick_broadcast_setup_oneshot - setup the broadcast device
  */
 void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
 {
-       bc->event_handler = tick_handle_oneshot_broadcast;
-       clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
-       bc->next_event.tv64 = KTIME_MAX;
+       /* Set it up only once ! */
+       if (bc->event_handler != tick_handle_oneshot_broadcast) {
+               int was_periodic = bc->mode == CLOCK_EVT_MODE_PERIODIC;
+               int cpu = smp_processor_id();
+               cpumask_t mask;
+
+               bc->event_handler = tick_handle_oneshot_broadcast;
+               clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
+
+               /* Take the do_timer update */
+               tick_do_timer_cpu = cpu;
+
+               /*
+                * We must be careful here. There might be other CPUs
+                * waiting for periodic broadcast. We need to set the
+                * oneshot_mask bits for those and program the
+                * broadcast device to fire.
+                */
+               mask = tick_broadcast_mask;
+               cpu_clear(cpu, mask);
+               cpus_or(tick_broadcast_oneshot_mask,
+                       tick_broadcast_oneshot_mask, mask);
+
+               if (was_periodic && !cpus_empty(mask)) {
+                       tick_broadcast_init_next_event(&mask, tick_next_period);
+                       tick_broadcast_set_event(tick_next_period, 1);
+               } else
+                       bc->next_event.tv64 = KTIME_MAX;
+       }
 }
 
 /*