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.comSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/apic/apic.c

@@ -537,6 +537,7 @@ static struct clock_event_device lapic_clockevent = {
 	.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,