1 files changed, 39 insertions, 2 deletions

diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index f113755695e2..7f32fe0e52cd 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -18,6 +18,7 @@
 #include <linux/percpu.h>
 #include <linux/profile.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 
 #include "tick-internal.h"
 
@@ -66,7 +67,8 @@ static void tick_broadcast_start_periodic(struct clock_event_device *bc)
  */
 int tick_check_broadcast_device(struct clock_event_device *dev)
 {
-        if ((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;
@@ -86,6 +88,22 @@ int tick_is_broadcast_device(struct clock_event_device *dev)
         return (dev && tick_broadcast_device.evtdev == dev);
 }
 
+static void err_broadcast(const struct cpumask *mask)
+{
+        pr_crit_once("Failed to broadcast timer tick. Some CPUs may be unresponsive.\n");
+}
+
+static void tick_device_setup_broadcast_func(struct clock_event_device *dev)
+{
+        if (!dev->broadcast)
+                dev->broadcast = tick_broadcast;
+        if (!dev->broadcast) {
+                pr_warn_once("%s depends on broadcast, but no broadcast function available\n",
+                             dev->name);
+                dev->broadcast = err_broadcast;
+        }
+}
+
 /*
  * Check, if the device is disfunctional and a place holder, which
  * needs to be handled by the broadcast device.
@@ -105,6 +123,7 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
          */
         if (!tick_device_is_functional(dev)) {
                 dev->event_handler = tick_handle_periodic;
+                tick_device_setup_broadcast_func(dev);
                 cpumask_set_cpu(cpu, tick_get_broadcast_mask());
                 tick_broadcast_start_periodic(tick_broadcast_device.evtdev);
                 ret = 1;
@@ -116,15 +135,33 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
                  */
                 if (!(dev->features & CLOCK_EVT_FEAT_C3STOP)) {
                         int cpu = smp_processor_id();
-
                         cpumask_clear_cpu(cpu, tick_get_broadcast_mask());
                         tick_broadcast_clear_oneshot(cpu);
+                } else {
+                        tick_device_setup_broadcast_func(dev);
                 }
         }
         raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
         return ret;
 }
 
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+int tick_receive_broadcast(void)
+{
+        struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
+        struct clock_event_device *evt = td->evtdev;
+
+        if (!evt)
+                return -ENODEV;
+
+        if (!evt->event_handler)
+                return -EINVAL;
+
+        evt->event_handler(evt);
+        return 0;
+}
+#endif
+
 /*
  * Broadcast the event to the cpus, which are set in the mask (mangled).
  */