ARM: perf: remove active_mask

Currently, pmu_hw_events::active_mask is used to keep track of which
events are active in hardware. As we can stop counters and their
interrupts, this is unnecessary.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

4 files changed, 18 insertions, 18 deletions

diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index dfde9283aec1..438482ff7498 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -57,12 +57,6 @@ struct cpu_hw_events {
          * an event. A 0 means that the counter can be used.
          */
         unsigned long           used_mask[BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)];
-
-        /*
-         * A 1 bit for an index indicates that the counter is actively being
-         * used.
-         */
-        unsigned long           active_mask[BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)];
 };
 static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events);
 
@@ -295,7 +289,6 @@ armpmu_del(struct perf_event *event, int flags)
 
         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);
@@ -327,7 +320,6 @@ armpmu_add(struct perf_event *event, int flags)
         event->hw.idx = idx;
         armpmu->disable(hwc, idx);
         cpuc->events[idx] = event;
-        set_bit(idx, cpuc->active_mask);
 
         hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
         if (flags & PERF_EF_START)
diff --git a/arch/arm/kernel/perf_event_v6.c b/arch/arm/kernel/perf_event_v6.c
index 87f29b553b8f..839012862264 100644
--- a/arch/arm/kernel/perf_event_v6.c
+++ b/arch/arm/kernel/perf_event_v6.c
@@ -462,6 +462,23 @@ armv6pmu_enable_event(struct hw_perf_event *hwc,
         raw_spin_unlock_irqrestore(&pmu_lock, flags);
 }
 
+static int counter_is_active(unsigned long pmcr, int idx)
+{
+        unsigned long mask = 0;
+        if (idx == ARMV6_CYCLE_COUNTER)
+                mask = ARMV6_PMCR_CCOUNT_IEN;
+        else if (idx == ARMV6_COUNTER0)
+                mask = ARMV6_PMCR_COUNT0_IEN;
+        else if (idx == ARMV6_COUNTER1)
+                mask = ARMV6_PMCR_COUNT1_IEN;
+
+        if (mask)
+                return pmcr & mask;
+
+        WARN_ONCE(1, "invalid counter number (%d)\n", idx);
+        return 0;
+}
+
 static irqreturn_t
 armv6pmu_handle_irq(int irq_num,
                     void *dev)
@@ -491,7 +508,7 @@ armv6pmu_handle_irq(int irq_num,
                 struct perf_event *event = cpuc->events[idx];
                 struct hw_perf_event *hwc;
 
-                if (!test_bit(idx, cpuc->active_mask))
+                if (!counter_is_active(pmcr, idx))
                         continue;
 
                 /*
diff --git a/arch/arm/kernel/perf_event_v7.c b/arch/arm/kernel/perf_event_v7.c
index fe6c931d2c4b..f4170fc228b6 100644
--- a/arch/arm/kernel/perf_event_v7.c
+++ b/arch/arm/kernel/perf_event_v7.c
@@ -1022,9 +1022,6 @@ static irqreturn_t armv7pmu_handle_irq(int irq_num, void *dev)
                 struct perf_event *event = cpuc->events[idx];
                 struct hw_perf_event *hwc;
 
-                if (!test_bit(idx, cpuc->active_mask))
-                        continue;
-
                 /*
                  * We have a single interrupt for all counters. Check that
                  * each counter has overflowed before we process it.
diff --git a/arch/arm/kernel/perf_event_xscale.c b/arch/arm/kernel/perf_event_xscale.c
index 54312fc45ca3..ca89a06c8e92 100644
--- a/arch/arm/kernel/perf_event_xscale.c
+++ b/arch/arm/kernel/perf_event_xscale.c
@@ -253,9 +253,6 @@ xscale1pmu_handle_irq(int irq_num, void *dev)
                 struct perf_event *event = cpuc->events[idx];
                 struct hw_perf_event *hwc;
 
-                if (!test_bit(idx, cpuc->active_mask))
-                        continue;
-
                 if (!xscale1_pmnc_counter_has_overflowed(pmnc, idx))
                         continue;
 
@@ -585,9 +582,6 @@ xscale2pmu_handle_irq(int irq_num, void *dev)
                 struct perf_event *event = cpuc->events[idx];
                 struct hw_perf_event *hwc;
 
-                if (!test_bit(idx, cpuc->active_mask))
-                        continue;
-
                 if (!xscale2_pmnc_counter_has_overflowed(pmnc, idx))
                         continue;