ARM: perf: prepare for moving CPU PMU code into separate file

The CPU PMU code is tightly coupled with generic ARM PMU handling code.
This makes it cumbersome when trying to add support for other ARM PMUs
(e.g. interconnect, L2 cache controller, bus) as the generic parts of
the code are not readily reusable.

This patch cleans up perf_event.c so that reusable code is exposed via
header files to other potential PMU drivers. The CPU code is
consistently named to identify it as such and also to prepare for moving
it into a separate file.

Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 27 insertions, 42 deletions

diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 7c29914..9e3afd1 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -29,26 +29,17 @@
 #include <asm/pmu.h>
 #include <asm/stacktrace.h>
 
-/*
- * ARMv6 supports a maximum of 3 events, starting from index 0. If we add
- * another platform that supports more, we need to increase this to be the
- * largest of all platforms.
- *
- * ARMv7 supports up to 32 events:
- *  cycle counter CCNT + 31 events counters CNT0..30.
- *  Cortex-A8 has 1+4 counters, Cortex-A9 has 1+6 counters.
- */
-#define ARMPMU_MAX_HWEVENTS		32
+/* Set at runtime when we know what CPU type we are. */
+static struct arm_pmu *cpu_pmu;
 
 static DEFINE_PER_CPU(struct perf_event * [ARMPMU_MAX_HWEVENTS], hw_events);
 static DEFINE_PER_CPU(unsigned long [BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)], used_mask);
 static DEFINE_PER_CPU(struct pmu_hw_events, cpu_hw_events);
 
-#define to_arm_pmu(p) (container_of(p, struct arm_pmu, pmu))
-
-/* Set at runtime when we know what CPU type we are. */
-static struct arm_pmu *cpu_pmu;
-
+/*
+ * Despite the names, these two functions are CPU-specific and are used
+ * by the OProfile/perf code.
+ */
 const char *perf_pmu_name(void)
 {
 	if (!cpu_pmu)
@@ -69,13 +60,6 @@ int perf_num_counters(void)
 }
 EXPORT_SYMBOL_GPL(perf_num_counters);
 
-#define HW_OP_UNSUPPORTED		0xFFFF
-
-#define C(_x) \
-	PERF_COUNT_HW_CACHE_##_x
-
-#define CACHE_OP_UNSUPPORTED		0xFFFF
-
 static int
 armpmu_map_cache_event(const unsigned (*cache_map)
 				      [PERF_COUNT_HW_CACHE_MAX]
@@ -106,7 +90,7 @@ armpmu_map_cache_event(const unsigned (*cache_map)
 }
 
 static int
-armpmu_map_event(const unsigned (*event_map)[PERF_COUNT_HW_MAX], u64 config)
+armpmu_map_hw_event(const unsigned (*event_map)[PERF_COUNT_HW_MAX], u64 config)
 {
 	int mapping = (*event_map)[config];
 	return mapping == HW_OP_UNSUPPORTED ? -ENOENT : mapping;
@@ -118,19 +102,20 @@ armpmu_map_raw_event(u32 raw_event_mask, u64 config)
 	return (int)(config & raw_event_mask);
 }
 
-static int map_cpu_event(struct perf_event *event,
-			 const unsigned (*event_map)[PERF_COUNT_HW_MAX],
-			 const unsigned (*cache_map)
-					[PERF_COUNT_HW_CACHE_MAX]
-					[PERF_COUNT_HW_CACHE_OP_MAX]
-					[PERF_COUNT_HW_CACHE_RESULT_MAX],
-			 u32 raw_event_mask)
+int
+armpmu_map_event(struct perf_event *event,
+		 const unsigned (*event_map)[PERF_COUNT_HW_MAX],
+		 const unsigned (*cache_map)
+				[PERF_COUNT_HW_CACHE_MAX]
+				[PERF_COUNT_HW_CACHE_OP_MAX]
+				[PERF_COUNT_HW_CACHE_RESULT_MAX],
+		 u32 raw_event_mask)
 {
 	u64 config = event->attr.config;
 
 	switch (event->attr.type) {
 	case PERF_TYPE_HARDWARE:
-		return armpmu_map_event(event_map, config);
+		return armpmu_map_hw_event(event_map, config);
 	case PERF_TYPE_HW_CACHE:
 		return armpmu_map_cache_event(cache_map, config);
 	case PERF_TYPE_RAW:
@@ -594,6 +579,10 @@ static int armpmu_runtime_suspend(struct device *dev)
 }
 #endif
 
+const struct dev_pm_ops armpmu_dev_pm_ops = {
+	SET_RUNTIME_PM_OPS(armpmu_runtime_suspend, armpmu_runtime_resume, NULL)
+};
+
 static void __init armpmu_init(struct arm_pmu *armpmu)
 {
 	atomic_set(&armpmu->active_events, 0);
@@ -624,7 +613,7 @@ int armpmu_register(struct arm_pmu *armpmu, char *name, int type)
 #include "perf_event_v6.c"
 #include "perf_event_v7.c"
 
-static struct pmu_hw_events *armpmu_get_cpu_events(void)
+static struct pmu_hw_events *cpu_pmu_get_cpu_events(void)
 {
 	return &__get_cpu_var(cpu_hw_events);
 }
@@ -638,7 +627,7 @@ static void __devinit cpu_pmu_init(struct arm_pmu *cpu_pmu)
 		events->used_mask = per_cpu(used_mask, cpu);
 		raw_spin_lock_init(&events->pmu_lock);
 	}
-	cpu_pmu->get_hw_events = armpmu_get_cpu_events;
+	cpu_pmu->get_hw_events = cpu_pmu_get_cpu_events;
 
 	/* Ensure the PMU has sane values out of reset. */
 	if (cpu_pmu && cpu_pmu->reset)
@@ -651,8 +640,8 @@ static void __devinit cpu_pmu_init(struct arm_pmu *cpu_pmu)
  * UNKNOWN at reset, the PMU must be explicitly reset to avoid reading
  * junk values out of them.
  */
-static int __cpuinit pmu_cpu_notify(struct notifier_block *b,
-					unsigned long action, void *hcpu)
+static int __cpuinit cpu_pmu_notify(struct notifier_block *b,
+				    unsigned long action, void *hcpu)
 {
 	if ((action & ~CPU_TASKS_FROZEN) != CPU_STARTING)
 		return NOTIFY_DONE;
@@ -663,12 +652,8 @@ static int __cpuinit pmu_cpu_notify(struct notifier_block *b,
 	return NOTIFY_OK;
 }
 
-static struct notifier_block __cpuinitdata pmu_cpu_notifier = {
-	.notifier_call = pmu_cpu_notify,
-};
-
-static const struct dev_pm_ops armpmu_dev_pm_ops = {
-	SET_RUNTIME_PM_OPS(armpmu_runtime_suspend, armpmu_runtime_resume, NULL)
+static struct notifier_block __cpuinitdata cpu_pmu_hotplug_notifier = {
+	.notifier_call = cpu_pmu_notify,
 };
 
 /*
@@ -771,7 +756,7 @@ static int __devinit cpu_pmu_device_probe(struct platform_device *pdev)
 
 	cpu_pmu->plat_device = pdev;
 	cpu_pmu_init(cpu_pmu);
-	register_cpu_notifier(&pmu_cpu_notifier);
+	register_cpu_notifier(&cpu_pmu_hotplug_notifier);
 	armpmu_register(cpu_pmu, cpu_pmu->name, PERF_TYPE_RAW);
 
 	return 0;