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Subject[PATCH 1/5] x86/apic: Migrate to new 'set-state' interface
Date
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>
---
arch/x86/kernel/apic/apic.c | 86 +++++++++++++++++++++++++++------------------
1 file 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;
}

--
2.4.0


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