x86/apic: Migrate apic timer to new set_state interface

Migrate apic driver to the new 'set-state' interface provided by
clockevents core, the earlier 'set-mode' interface is marked obsolete
now.

This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.

We weren't doing anything while switching to resume mode and so that
callback isn't implemented.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linaro-kernel@lists.linaro.org
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Bandan Das <bsd@redhat.com>
Link: http://lkml.kernel.org/r/1896ac5989d27f2ac37f4786af9bd537e1921b83.1437042675.git.viresh.kumar@linaro.orgSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/apic/apic.c

@@ -462,40 +462,53 @@ static int lapic_next_deadline(unsigned long delta,
 	return 0;
 }
 
-/*
- * Setup the lapic timer in periodic or oneshot mode
- */
-static void lapic_timer_setup(enum clock_event_mode mode,
-			      struct clock_event_device *evt)
+static int lapic_timer_shutdown(struct clock_event_device *evt)
 {
 	unsigned long flags;
 	unsigned int v;
 
 	/* Lapic used as dummy for broadcast ? */
 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
-		return;
+		return 0;
 
 	local_irq_save(flags);
 
-	switch (mode) {
-	case CLOCK_EVT_MODE_PERIODIC:
-	case CLOCK_EVT_MODE_ONESHOT:
-		__setup_APIC_LVTT(lapic_timer_frequency,
-				  mode != CLOCK_EVT_MODE_PERIODIC, 1);
-		break;
-	case CLOCK_EVT_MODE_UNUSED:
-	case CLOCK_EVT_MODE_SHUTDOWN:
-		v = apic_read(APIC_LVTT);
-		v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
-		apic_write(APIC_LVTT, v);
-		apic_write(APIC_TMICT, 0);
-		break;
-	case CLOCK_EVT_MODE_RESUME:
-		/* Nothing to do here */
-		break;
-	}
+	v = apic_read(APIC_LVTT);
+	v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
+	apic_write(APIC_LVTT, v);
+	apic_write(APIC_TMICT, 0);
+
+	local_irq_restore(flags);
+
+	return 0;
+}
+
+static inline int
+lapic_timer_set_periodic_oneshot(struct clock_event_device *evt, bool oneshot)
+{
+	unsigned long flags;
+
+	/* Lapic used as dummy for broadcast ? */
+	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
+		return 0;
+
+	local_irq_save(flags);
+
+	__setup_APIC_LVTT(lapic_timer_frequency, oneshot, 1);
 
 	local_irq_restore(flags);
+
+	return 0;
+}
+
+static int lapic_timer_set_periodic(struct clock_event_device *evt)
+{
+	return lapic_timer_set_periodic_oneshot(evt, false);
+}
+
+static int lapic_timer_set_oneshot(struct clock_event_device *evt)
+{
+	return lapic_timer_set_periodic_oneshot(evt, true);
 }
 
 /*
@@ -513,15 +526,18 @@ 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_mode	= lapic_timer_setup,
-	.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_next_event		= lapic_next_event,
+	.broadcast		= lapic_timer_broadcast,
+	.rating			= 100,
+	.irq			= -1,
 };
 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
 
@@ -778,7 +794,7 @@ static int __init calibrate_APIC_clock(void)
 		 * Setup the apic timer manually
 		 */
 		levt->event_handler = lapic_cal_handler;
-		lapic_timer_setup(CLOCK_EVT_MODE_PERIODIC, levt);
+		lapic_timer_set_periodic(levt);
 		lapic_cal_loops = -1;
 
 		/* Let the interrupts run */
@@ -788,7 +804,7 @@ static int __init calibrate_APIC_clock(void)
 			cpu_relax();
 
 		/* Stop the lapic timer */
-		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);
+		lapic_timer_shutdown(levt);
 
 		/* Jiffies delta */
 		deltaj = lapic_cal_j2 - lapic_cal_j1;
@@ -878,7 +894,7 @@ static void local_apic_timer_interrupt(void)
 	if (!evt->event_handler) {
 		pr_warning("Spurious LAPIC timer interrupt on cpu %d\n", cpu);
 		/* Switch it off */
-		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
+		lapic_timer_shutdown(evt);
 		return;
 	}