clockevents: Cleanup dead cpu explicitely

[linux-2.6-block.git] / kernel / time / tick-common.c

diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index a5b877130ae98a5c92747af2f7ea3c8659160fcd..fac3e98fec4953ff68787e5a921ed6a8fbeea5f9 100644 (file)
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -332,14 +332,16 @@ out_bc:
        tick_install_broadcast_device(newdev);
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
 /*
  * Transfer the do_timer job away from a dying cpu.
  *
- * Called with interrupts disabled.
+ * Called with interrupts disabled. Not locking required. If
+ * tick_do_timer_cpu is owned by this cpu, nothing can change it.
  */
-void tick_handover_do_timer(int *cpup)
+void tick_handover_do_timer(void)
 {
-       if (*cpup == tick_do_timer_cpu) {
+       if (tick_do_timer_cpu == smp_processor_id()) {
                int cpu = cpumask_first(cpu_online_mask);
 
                tick_do_timer_cpu = (cpu < nr_cpu_ids) ? cpu :
@@ -354,9 +356,9 @@ void tick_handover_do_timer(int *cpup)
  * access the hardware device itself.
  * We just set the mode and remove it from the lists.
  */
-void tick_shutdown(unsigned int *cpup)
+void tick_shutdown(unsigned int cpu)
 {
-       struct tick_device *td = &per_cpu(tick_cpu_device, *cpup);
+       struct tick_device *td = &per_cpu(tick_cpu_device, cpu);
        struct clock_event_device *dev = td->evtdev;
 
        td->mode = TICKDEV_MODE_PERIODIC;
@@ -372,21 +374,35 @@ void tick_shutdown(unsigned int *cpup)
                td->evtdev = NULL;
        }
 }
+#endif
 
-void tick_suspend(void)
+/**
+ * tick_suspend_local - Suspend the local tick device
+ *
+ * Called from the local cpu for freeze with interrupts disabled.
+ *
+ * No locks required. Nothing can change the per cpu device.
+ */
+void tick_suspend_local(void)
 {
        struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
 
        clockevents_shutdown(td->evtdev);
 }
 
-void tick_resume(void)
+/**
+ * tick_resume_local - Resume the local tick device
+ *
+ * Called from the local CPU for unfreeze or XEN resume magic.
+ *
+ * No locks required. Nothing can change the per cpu device.
+ */
+void tick_resume_local(void)
 {
        struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
-       int broadcast = tick_resume_broadcast();
+       bool broadcast = tick_resume_check_broadcast();
 
        clockevents_tick_resume(td->evtdev);
-
        if (!broadcast) {
                if (td->mode == TICKDEV_MODE_PERIODIC)
                        tick_setup_periodic(td->evtdev, 0);
@@ -395,6 +411,35 @@ void tick_resume(void)
        }
 }
 
+/**
+ * tick_suspend - Suspend the tick and the broadcast device
+ *
+ * Called from syscore_suspend() via timekeeping_suspend with only one
+ * CPU online and interrupts disabled or from tick_unfreeze() under
+ * tick_freeze_lock.
+ *
+ * No locks required. Nothing can change the per cpu device.
+ */
+void tick_suspend(void)
+{
+       tick_suspend_local();
+       tick_suspend_broadcast();
+}
+
+/**
+ * tick_resume - Resume the tick and the broadcast device
+ *
+ * Called from syscore_resume() via timekeeping_resume with only one
+ * CPU online and interrupts disabled.
+ *
+ * No locks required. Nothing can change the per cpu device.
+ */
+void tick_resume(void)
+{
+       tick_resume_broadcast();
+       tick_resume_local();
+}
+
 static DEFINE_RAW_SPINLOCK(tick_freeze_lock);
 static unsigned int tick_freeze_depth;
 
@@ -415,8 +460,7 @@ void tick_freeze(void)
        if (tick_freeze_depth == num_online_cpus()) {
                timekeeping_suspend();
        } else {
-               tick_suspend();
-               tick_suspend_broadcast();
+               tick_suspend_local();
        }
 
        raw_spin_unlock(&tick_freeze_lock);