#include <linux/profile.h>
#include <linux/sched.h>
#include <linux/smp.h>
+#include <linux/module.h>
#include "tick-internal.h"
/*
* Check, if the device can be utilized as broadcast device:
*/
-int tick_check_broadcast_device(struct clock_event_device *dev)
+static bool tick_check_broadcast_device(struct clock_event_device *curdev,
+ struct clock_event_device *newdev)
+{
+ if ((newdev->features & CLOCK_EVT_FEAT_DUMMY) ||
+ (newdev->features & CLOCK_EVT_FEAT_C3STOP))
+ return false;
+
+ if (tick_broadcast_device.mode == TICKDEV_MODE_ONESHOT &&
+ !(newdev->features & CLOCK_EVT_FEAT_ONESHOT))
+ return false;
+
+ return !curdev || newdev->rating > curdev->rating;
+}
+
+/*
+ * Conditionally install/replace broadcast device
+ */
+void tick_install_broadcast_device(struct clock_event_device *dev)
{
struct clock_event_device *cur = tick_broadcast_device.evtdev;
- if ((dev->features & CLOCK_EVT_FEAT_DUMMY) ||
- (tick_broadcast_device.evtdev &&
- tick_broadcast_device.evtdev->rating >= dev->rating) ||
- (dev->features & CLOCK_EVT_FEAT_C3STOP))
- return 0;
+ if (!tick_check_broadcast_device(cur, dev))
+ return;
+
+ if (!try_module_get(dev->owner))
+ return;
- clockevents_exchange_device(tick_broadcast_device.evtdev, dev);
+ clockevents_exchange_device(cur, dev);
if (cur)
cur->event_handler = clockevents_handle_noop;
tick_broadcast_device.evtdev = dev;
*/
if (dev->features & CLOCK_EVT_FEAT_ONESHOT)
tick_clock_notify();
- return 1;
}
/*
if (cpumask_test_cpu(cpu, tick_broadcast_oneshot_mask)) {
struct tick_device *td = &per_cpu(tick_cpu_device, cpu);
- clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_ONESHOT);
+ /*
+ * We might be in the middle of switching over from
+ * periodic to oneshot. If the CPU has not yet
+ * switched over, leave the device alone.
+ */
+ if (td->mode == TICKDEV_MODE_ONESHOT) {
+ clockevents_set_mode(td->evtdev,
+ CLOCK_EVT_MODE_ONESHOT);
+ }
}
}
cpumask_or(tmpmask, tmpmask, tick_broadcast_force_mask);
cpumask_clear(tick_broadcast_force_mask);
+ /*
+ * Sanity check. Catch the case where we try to broadcast to
+ * offline cpus.
+ */
+ if (WARN_ON_ONCE(!cpumask_subset(tmpmask, cpu_online_mask)))
+ cpumask_and(tmpmask, tmpmask, cpu_online_mask);
+
/*
* Wakeup the cpus which have an expired event.
*/
static void tick_broadcast_clear_oneshot(int cpu)
{
cpumask_clear_cpu(cpu, tick_broadcast_oneshot_mask);
+ cpumask_clear_cpu(cpu, tick_broadcast_pending_mask);
}
static void tick_broadcast_init_next_event(struct cpumask *mask,
raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
/*
- * Clear the broadcast mask flag for the dead cpu, but do not
- * stop the broadcast device!
+ * Clear the broadcast masks for the dead cpu, but do not stop
+ * the broadcast device!
*/
cpumask_clear_cpu(cpu, tick_broadcast_oneshot_mask);
+ cpumask_clear_cpu(cpu, tick_broadcast_pending_mask);
+ cpumask_clear_cpu(cpu, tick_broadcast_force_mask);
raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}