x86/apic: Implement set_state_oneshot_stopped() callback

When clock_event_device::set_state_oneshot_stopped() is not implemented,
hrtimer_cancel() can't stop the clock when there is no more timer in
the queue. So the ghost of the freshly cancelled hrtimer haunts us back
later with an extra interrupt:

          <idle>-0     [002] d..2  2248.557659: hrtimer_cancel: hrtimer=ffff88021fa92d80
          <idle>-0     [002] d.h1  2249.303659: local_timer_entry: vector=239

So let's implement this missing callback for the lapic clock. This
consist in calling its set_state_shutdown() callback. There don't seem
to be a lighter way to stop the clock. Simply writing 0 to APIC_TMICT
won't be enough to stop the clock and avoid the extra interrupt, as
opposed to what is specified in the specs. We must also mask the
timer interrupt in the device.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: http://lkml.kernel.org/r/1483029949-6925-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 5c4fdcfda10908c4a9f328fe348ff4d95dcad712..fdb9c46227cc23b07744b9d2d75efa29162c4744 100644 (file)
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -529,18 +529,19 @@ static void lapic_timer_broadcast(const struct cpumask *mask)
  * The local apic timer can be used for any function which is CPU local.
  */
 static struct clock_event_device lapic_clockevent = {
-       .name                   = "lapic",
-       .features               = CLOCK_EVT_FEAT_PERIODIC |
-                                 CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP
-                                 | CLOCK_EVT_FEAT_DUMMY,
-       .shift                  = 32,
-       .set_state_shutdown     = lapic_timer_shutdown,
-       .set_state_periodic     = lapic_timer_set_periodic,
-       .set_state_oneshot      = lapic_timer_set_oneshot,
-       .set_next_event         = lapic_next_event,
-       .broadcast              = lapic_timer_broadcast,
-       .rating                 = 100,
-       .irq                    = -1,
+       .name                           = "lapic",
+       .features                       = CLOCK_EVT_FEAT_PERIODIC |
+                                         CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP
+                                         | CLOCK_EVT_FEAT_DUMMY,
+       .shift                          = 32,
+       .set_state_shutdown             = lapic_timer_shutdown,
+       .set_state_periodic             = lapic_timer_set_periodic,
+       .set_state_oneshot              = lapic_timer_set_oneshot,
+       .set_state_oneshot_stopped      = lapic_timer_shutdown,
+       .set_next_event                 = lapic_next_event,
+       .broadcast                      = lapic_timer_broadcast,
+       .rating                         = 100,
+       .irq                            = -1,
 };
 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);