perf: Rework the PMU methods

[mv-sheeva.git] / arch / arm / kernel / perf_event.c

diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 3343f3f4b973540d6e520d6bba1b56ec7a800d05..448cfa6b3ef09ccd13d78850eb8251f5d26078d7 100644 (file)
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -221,46 +221,56 @@ again:
 }
 
 static void
-armpmu_disable(struct perf_event *event)
+armpmu_read(struct perf_event *event)
 {
-       struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
        struct hw_perf_event *hwc = &event->hw;
-       int idx = hwc->idx;
-
-       WARN_ON(idx < 0);
-
-       clear_bit(idx, cpuc->active_mask);
-       armpmu->disable(hwc, idx);
-
-       barrier();
 
-       armpmu_event_update(event, hwc, idx);
-       cpuc->events[idx] = NULL;
-       clear_bit(idx, cpuc->used_mask);
+       /* Don't read disabled counters! */
+       if (hwc->idx < 0)
+               return;
 
-       perf_event_update_userpage(event);
+       armpmu_event_update(event, hwc, hwc->idx);
 }
 
 static void
-armpmu_read(struct perf_event *event)
+armpmu_stop(struct perf_event *event, int flags)
 {
        struct hw_perf_event *hwc = &event->hw;
 
-       /* Don't read disabled counters! */
-       if (hwc->idx < 0)
+       if (!armpmu)
                return;
 
-       armpmu_event_update(event, hwc, hwc->idx);
+       /*
+        * ARM pmu always has to update the counter, so ignore
+        * PERF_EF_UPDATE, see comments in armpmu_start().
+        */
+       if (!(hwc->state & PERF_HES_STOPPED)) {
+               armpmu->disable(hwc, hwc->idx);
+               barrier(); /* why? */
+               armpmu_event_update(event, hwc, hwc->idx);
+               hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
+       }
 }
 
 static void
-armpmu_unthrottle(struct perf_event *event)
+armpmu_start(struct perf_event *event, int flags)
 {
        struct hw_perf_event *hwc = &event->hw;
 
+       if (!armpmu)
+               return;
+
+       /*
+        * ARM pmu always has to reprogram the period, so ignore
+        * PERF_EF_RELOAD, see the comment below.
+        */
+       if (flags & PERF_EF_RELOAD)
+               WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
+
+       hwc->state = 0;
        /*
         * Set the period again. Some counters can't be stopped, so when we
-        * were throttled we simply disabled the IRQ source and the counter
+        * were stopped we simply disabled the IRQ source and the counter
         * may have been left counting. If we don't do this step then we may
         * get an interrupt too soon or *way* too late if the overflow has
         * happened since disabling.
@@ -269,8 +279,25 @@ armpmu_unthrottle(struct perf_event *event)
        armpmu->enable(hwc, hwc->idx);
 }
 
+static void
+armpmu_del(struct perf_event *event, int flags)
+{
+       struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+       struct hw_perf_event *hwc = &event->hw;
+       int idx = hwc->idx;
+
+       WARN_ON(idx < 0);
+
+       clear_bit(idx, cpuc->active_mask);
+       armpmu_stop(event, PERF_EF_UPDATE);
+       cpuc->events[idx] = NULL;
+       clear_bit(idx, cpuc->used_mask);
+
+       perf_event_update_userpage(event);
+}
+
 static int
-armpmu_enable(struct perf_event *event)
+armpmu_add(struct perf_event *event, int flags)
 {
        struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
        struct hw_perf_event *hwc = &event->hw;
@@ -295,11 +322,9 @@ armpmu_enable(struct perf_event *event)
        cpuc->events[idx] = event;
        set_bit(idx, cpuc->active_mask);
 
-       /* Set the period for the event. */
-       armpmu_event_set_period(event, hwc, idx);
-
-       /* Enable the event. */
-       armpmu->enable(hwc, idx);
+       hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+       if (flags & PERF_EF_START)
+               armpmu_start(event, PERF_EF_RELOAD);
 
        /* Propagate our changes to the userspace mapping. */
        perf_event_update_userpage(event);
@@ -534,7 +559,7 @@ static int armpmu_event_init(struct perf_event *event)
        return err;
 }
 
-static void armpmu_pmu_enable(struct pmu *pmu)
+static void armpmu_enable(struct pmu *pmu)
 {
        /* Enable all of the perf events on hardware. */
        int idx;
@@ -555,20 +580,21 @@ static void armpmu_pmu_enable(struct pmu *pmu)
        armpmu->start();
 }
 
-static void armpmu_pmu_disable(struct pmu *pmu)
+static void armpmu_disable(struct pmu *pmu)
 {
        if (armpmu)
                armpmu->stop();
 }
 
 static struct pmu pmu = {
-       .pmu_enable = armpmu_pmu_enable,
-       .pmu_disable= armpmu_pmu_disable,
-       .event_init = armpmu_event_init,
-       .enable     = armpmu_enable,
-       .disable    = armpmu_disable,
-       .unthrottle = armpmu_unthrottle,
-       .read       = armpmu_read,
+       .pmu_enable     = armpmu_enable,
+       .pmu_disable    = armpmu_disable,
+       .event_init     = armpmu_event_init,
+       .add            = armpmu_add,
+       .del            = armpmu_del,
+       .start          = armpmu_start,
+       .stop           = armpmu_stop,
+       .read           = armpmu_read,
 };
 
 /*