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

1 files changed, 51 insertions, 35 deletions

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index dcb52850a28f..ecd6705c9f4b 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/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;
         }