ARM: perf: consistently use struct perf_event in arm_pmu functions

The arm_pmu functions have wildly varied parameters which can often be
derived from struct perf_event.

This patch changes the arm_pmu function prototypes so that struct
perf_event pointers are passed in preference to fields that can be
derived from the event.

Signed-off-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index f8406af..1cfa3f3 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -86,12 +86,10 @@
 	return -ENOENT;
 }
 
-int
-armpmu_event_set_period(struct perf_event *event,
-			struct hw_perf_event *hwc,
-			int idx)
+int armpmu_event_set_period(struct perf_event *event)
 {
 	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
 	s64 left = local64_read(&hwc->period_left);
 	s64 period = hwc->sample_period;
 	int ret = 0;
@@ -119,24 +117,22 @@
 
 	local64_set(&hwc->prev_count, (u64)-left);
 
-	armpmu->write_counter(idx, (u64)(-left) & 0xffffffff);
+	armpmu->write_counter(event, (u64)(-left) & 0xffffffff);
 
 	perf_event_update_userpage(event);
 
 	return ret;
 }
 
-u64
-armpmu_event_update(struct perf_event *event,
-		    struct hw_perf_event *hwc,
-		    int idx)
+u64 armpmu_event_update(struct perf_event *event)
 {
 	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
 	u64 delta, prev_raw_count, new_raw_count;
 
 again:
 	prev_raw_count = local64_read(&hwc->prev_count);
-	new_raw_count = armpmu->read_counter(idx);
+	new_raw_count = armpmu->read_counter(event);
 
 	if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
 			     new_raw_count) != prev_raw_count)
@@ -159,7 +155,7 @@
 	if (hwc->idx < 0)
 		return;
 
-	armpmu_event_update(event, hwc, hwc->idx);
+	armpmu_event_update(event);
 }
 
 static void
@@ -173,14 +169,13 @@
 	 * PERF_EF_UPDATE, see comments in armpmu_start().
 	 */
 	if (!(hwc->state & PERF_HES_STOPPED)) {
-		armpmu->disable(hwc, hwc->idx);
-		armpmu_event_update(event, hwc, hwc->idx);
+		armpmu->disable(event);
+		armpmu_event_update(event);
 		hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
 	}
 }
 
-static void
-armpmu_start(struct perf_event *event, int flags)
+static void armpmu_start(struct perf_event *event, int flags)
 {
 	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 	struct hw_perf_event *hwc = &event->hw;
@@ -200,8 +195,8 @@
 	 * get an interrupt too soon or *way* too late if the overflow has
 	 * happened since disabling.
 	 */
-	armpmu_event_set_period(event, hwc, hwc->idx);
-	armpmu->enable(hwc, hwc->idx);
+	armpmu_event_set_period(event);
+	armpmu->enable(event);
 }
 
 static void
@@ -233,7 +228,7 @@
 	perf_pmu_disable(event->pmu);
 
 	/* If we don't have a space for the counter then finish early. */
-	idx = armpmu->get_event_idx(hw_events, hwc);
+	idx = armpmu->get_event_idx(hw_events, event);
 	if (idx < 0) {
 		err = idx;
 		goto out;
@@ -244,7 +239,7 @@
 	 * sure it is disabled.
 	 */
 	event->hw.idx = idx;
-	armpmu->disable(hwc, idx);
+	armpmu->disable(event);
 	hw_events->events[idx] = event;
 
 	hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
@@ -264,13 +259,12 @@
 	       struct perf_event *event)
 {
 	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
-	struct hw_perf_event fake_event = event->hw;
 	struct pmu *leader_pmu = event->group_leader->pmu;
 
 	if (event->pmu != leader_pmu || event->state <= PERF_EVENT_STATE_OFF)
 		return 1;
 
-	return armpmu->get_event_idx(hw_events, &fake_event) >= 0;
+	return armpmu->get_event_idx(hw_events, event) >= 0;
 }
 
 static int
@@ -316,7 +310,7 @@
 static void
 armpmu_release_hardware(struct arm_pmu *armpmu)
 {
-	armpmu->free_irq();
+	armpmu->free_irq(armpmu);
 	pm_runtime_put_sync(&armpmu->plat_device->dev);
 }
 
@@ -330,7 +324,7 @@
 		return -ENODEV;
 
 	pm_runtime_get_sync(&pmu_device->dev);
-	err = armpmu->request_irq(armpmu_dispatch_irq);
+	err = armpmu->request_irq(armpmu, armpmu_dispatch_irq);
 	if (err) {
 		armpmu_release_hardware(armpmu);
 		return err;
@@ -465,13 +459,13 @@
 	int enabled = bitmap_weight(hw_events->used_mask, armpmu->num_events);
 
 	if (enabled)
-		armpmu->start();
+		armpmu->start(armpmu);
 }
 
 static void armpmu_disable(struct pmu *pmu)
 {
 	struct arm_pmu *armpmu = to_arm_pmu(pmu);
-	armpmu->stop();
+	armpmu->stop(armpmu);
 }
 
 #ifdef CONFIG_PM_RUNTIME