perf: Rework the PMU methods

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

diff --git a/arch/powerpc/kernel/perf_event.c b/arch/powerpc/kernel/perf_event.c
index deb84bbcb0e68978735fff166979b00980083ea5..9cb4924b6c07837a47718bb1c842eb40a96df7b8 100644 (file)
--- a/arch/powerpc/kernel/perf_event.c
+++ b/arch/powerpc/kernel/perf_event.c
@@ -402,6 +402,9 @@ static void power_pmu_read(struct perf_event *event)
 {
        s64 val, delta, prev;
 
+       if (event->hw.state & PERF_HES_STOPPED)
+               return;
+
        if (!event->hw.idx)
                return;
        /*
@@ -517,7 +520,7 @@ static void write_mmcr0(struct cpu_hw_events *cpuhw, unsigned long mmcr0)
  * Disable all events to prevent PMU interrupts and to allow
  * events to be added or removed.
  */
-static void power_pmu_pmu_disable(struct pmu *pmu)
+static void power_pmu_disable(struct pmu *pmu)
 {
        struct cpu_hw_events *cpuhw;
        unsigned long flags;
@@ -565,7 +568,7 @@ static void power_pmu_pmu_disable(struct pmu *pmu)
  * If we were previously disabled and events were added, then
  * put the new config on the PMU.
  */
-static void power_pmu_pmu_enable(struct pmu *pmu)
+static void power_pmu_enable(struct pmu *pmu)
 {
        struct perf_event *event;
        struct cpu_hw_events *cpuhw;
@@ -672,6 +675,8 @@ static void power_pmu_pmu_enable(struct pmu *pmu)
                }
                local64_set(&event->hw.prev_count, val);
                event->hw.idx = idx;
+               if (event->hw.state & PERF_HES_STOPPED)
+                       val = 0;
                write_pmc(idx, val);
                perf_event_update_userpage(event);
        }
@@ -727,7 +732,7 @@ static int collect_events(struct perf_event *group, int max_count,
  * re-enable the PMU in order to get hw_perf_enable to do the
  * actual work of reconfiguring the PMU.
  */
-static int power_pmu_enable(struct perf_event *event)
+static int power_pmu_add(struct perf_event *event, int ef_flags)
 {
        struct cpu_hw_events *cpuhw;
        unsigned long flags;
@@ -749,6 +754,9 @@ static int power_pmu_enable(struct perf_event *event)
        cpuhw->events[n0] = event->hw.config;
        cpuhw->flags[n0] = event->hw.event_base;
 
+       if (!(ef_flags & PERF_EF_START))
+               event->hw.state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+
        /*
         * If group events scheduling transaction was started,
         * skip the schedulability test here, it will be peformed
@@ -777,7 +785,7 @@ nocheck:
 /*
  * Remove a event from the PMU.
  */
-static void power_pmu_disable(struct perf_event *event)
+static void power_pmu_del(struct perf_event *event, int ef_flags)
 {
        struct cpu_hw_events *cpuhw;
        long i;
@@ -826,27 +834,53 @@ static void power_pmu_disable(struct perf_event *event)
 }
 
 /*
- * Re-enable interrupts on a event after they were throttled
- * because they were coming too fast.
+ * POWER-PMU does not support disabling individual counters, hence
+ * program their cycle counter to their max value and ignore the interrupts.
  */
-static void power_pmu_unthrottle(struct perf_event *event)
+
+static void power_pmu_start(struct perf_event *event, int ef_flags)
 {
-       s64 val, left;
        unsigned long flags;
+       s64 left;
 
        if (!event->hw.idx || !event->hw.sample_period)
                return;
+
+       if (!(event->hw.state & PERF_HES_STOPPED))
+               return;
+
+       if (ef_flags & PERF_EF_RELOAD)
+               WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
+
+       local_irq_save(flags);
+       perf_pmu_disable(event->pmu);
+
+       event->hw.state = 0;
+       left = local64_read(&event->hw.period_left);
+       write_pmc(event->hw.idx, left);
+
+       perf_event_update_userpage(event);
+       perf_pmu_enable(event->pmu);
+       local_irq_restore(flags);
+}
+
+static void power_pmu_stop(struct perf_event *event, int ef_flags)
+{
+       unsigned long flags;
+
+       if (!event->hw.idx || !event->hw.sample_period)
+               return;
+
+       if (event->hw.state & PERF_HES_STOPPED)
+               return;
+
        local_irq_save(flags);
        perf_pmu_disable(event->pmu);
+
        power_pmu_read(event);
-       left = event->hw.sample_period;
-       event->hw.last_period = left;
-       val = 0;
-       if (left < 0x80000000L)
-               val = 0x80000000L - left;
-       write_pmc(event->hw.idx, val);
-       local64_set(&event->hw.prev_count, val);
-       local64_set(&event->hw.period_left, left);
+       event->hw.state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
+       write_pmc(event->hw.idx, 0);
+
        perf_event_update_userpage(event);
        perf_pmu_enable(event->pmu);
        local_irq_restore(flags);
@@ -1131,13 +1165,14 @@ static int power_pmu_event_init(struct perf_event *event)
 }
 
 struct pmu power_pmu = {
-       .pmu_enable     = power_pmu_pmu_enable,
-       .pmu_disable    = power_pmu_pmu_disable,
+       .pmu_enable     = power_pmu_enable,
+       .pmu_disable    = power_pmu_disable,
        .event_init     = power_pmu_event_init,
-       .enable         = power_pmu_enable,
-       .disable        = power_pmu_disable,
+       .add            = power_pmu_add,
+       .del            = power_pmu_del,
+       .start          = power_pmu_start,
+       .stop           = power_pmu_stop,
        .read           = power_pmu_read,
-       .unthrottle     = power_pmu_unthrottle,
        .start_txn      = power_pmu_start_txn,
        .cancel_txn     = power_pmu_cancel_txn,
        .commit_txn     = power_pmu_commit_txn,
@@ -1155,6 +1190,11 @@ static void record_and_restart(struct perf_event *event, unsigned long val,
        s64 prev, delta, left;
        int record = 0;
 
+       if (event->hw.state & PERF_HES_STOPPED) {
+               write_pmc(event->hw.idx, 0);
+               return;
+       }
+
        /* we don't have to worry about interrupts here */
        prev = local64_read(&event->hw.prev_count);
        delta = (val - prev) & 0xfffffffful;
@@ -1177,6 +1217,11 @@ static void record_and_restart(struct perf_event *event, unsigned long val,
                        val = 0x80000000LL - left;
        }
 
+       write_pmc(event->hw.idx, val);
+       local64_set(&event->hw.prev_count, val);
+       local64_set(&event->hw.period_left, left);
+       perf_event_update_userpage(event);
+
        /*
         * Finally record data if requested.
         */
@@ -1189,23 +1234,9 @@ static void record_and_restart(struct perf_event *event, unsigned long val,
                if (event->attr.sample_type & PERF_SAMPLE_ADDR)
                        perf_get_data_addr(regs, &data.addr);
 
-               if (perf_event_overflow(event, nmi, &data, regs)) {
-                       /*
-                        * Interrupts are coming too fast - throttle them
-                        * by setting the event to 0, so it will be
-                        * at least 2^30 cycles until the next interrupt
-                        * (assuming each event counts at most 2 counts
-                        * per cycle).
-                        */
-                       val = 0;
-                       left = ~0ULL >> 1;
-               }
+               if (perf_event_overflow(event, nmi, &data, regs))
+                       power_pmu_stop(event, 0);
        }
-
-       write_pmc(event->hw.idx, val);
-       local64_set(&event->hw.prev_count, val);
-       local64_set(&event->hw.period_left, left);
-       perf_event_update_userpage(event);
 }
 
 /*