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* [RFC PATCH 00/15] ARM: perf: support multiple PMUs
@ 2011-08-15 13:55 Mark Rutland
  2011-08-15 13:55 ` [RFC PATCH 01/15] perf: provide PMU when initing events Mark Rutland
                   ` (15 more replies)
  0 siblings, 16 replies; 18+ messages in thread
From: Mark Rutland @ 2011-08-15 13:55 UTC (permalink / raw)
  To: linux-arm-kernel

System (AKA nest or uncore) PMUs exist on devices which are not affine
to a single CPU. They usually cannot be directly associated with
individual tasks and are asynchronous with respect to the current
execution. Examples of devices which could have system PMUs include L2
cache controllers, GPUs and memory buses.

The following patch series refactors the ARM PMU backend, enabling
new PMUs to reuse the existing code. This should allow for system PMUs
to be supported in future. Further work will be required to get perf to
fully understand system PMUs, but this provides something usable.

The framework is intended to be used by system PMUs which hang off core
platform components (e.g. L2 cache, AXI bus). If a device is complex
enough or separate enough from core functionality to have its own
driver, it should implement its own PMU handling using the core perf
API directly.

The first patch ("perf: provide PMU when initing events") is currently
sitting in the tip tree, but as it's required for event initialization
to function (and hence for the PMU to be usable), it's provided here
for convenience.

The series is based on Will Deacon's perf-updates branch at:
	git://linux-arm.org/linux-2.6-wd.git perf-updates

An example driver using the framework (supporting the PMU present in
L220/PL310 level 2 cache controllers) can be found at:
	git://linux-arm.org/linux-2.6-wd.git perf-l2x0-wip

Any comments would be welcome.

Thanks,
Mark.

Mark Rutland (15):
  perf: provide PMU when initing events
  ARM: perf: only register a CPU PMU when present
  ARM: perf: clean up event group validation
  ARM: perf: remove active_mask
  ARM: perf: move active_events into struct arm_pmu
  ARM: perf: move platform device to struct arm_pmu
  ARM: perf: indirect access to cpu_hw_events
  ARM: perf: remove unnecessary armpmu->stop
  ARM: perf: lock PMU registers per-CPU
  ARM: perf: add type field to struct arm_pmu
  ARM: perf: refactor event mapping
  ARM: perf: add support for multiple PMUs
  ARM: perf: remove event limit from pmu_hw_events
  ARM: perf: remove cpu-related misnomers
  ARM: perf: move arm_pmu into <asm/pmu.h>

 arch/arm/include/asm/pmu.h          |   64 +++++++
 arch/arm/kernel/perf_event.c        |  318 +++++++++++++++++------------------
 arch/arm/kernel/perf_event_v6.c     |   73 ++++++---
 arch/arm/kernel/perf_event_v7.c     |   74 +++++---
 arch/arm/kernel/perf_event_xscale.c |   76 +++++----
 kernel/events/core.c                |    4 +-
 6 files changed, 359 insertions(+), 250 deletions(-)

^ permalink raw reply	[flat|nested] 18+ messages in thread
* [RFC PATCH 12/15] ARM: perf: add support for multiple PMUs
@ 2011-04-28 15:27 Mark Rutland
  0 siblings, 0 replies; 18+ messages in thread
From: Mark Rutland @ 2011-04-28 15:27 UTC (permalink / raw)
  To: linux-arm-kernel

Currently, a single static instance of struct pmu is used when
registering an ARM PMU with the main perf subsystem. This limits
the ARM perf code to supporting a single PMU.

This patch replaces the static struct pmu instance with a member
variable on struct arm_pmu. This provides bidirectional mapping
between the two structs, and therefore allows for support of multiple
PMUs. The function 'to_arm_pmu' is provided for convenience.

PMU-generic functions are also updated to use the new mapping, and
PMU-generic initialisation of the member variables is moved into a new
function: armpmu_init.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
---
 arch/arm/kernel/perf_event.c |   63 +++++++++++++++++++++++++++--------------
 1 files changed, 41 insertions(+), 22 deletions(-)

diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index b13bf23..7f31eff 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -59,6 +59,7 @@ struct cpu_hw_events {
 static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events);
 
 struct arm_pmu {
+	struct pmu	pmu;
 	enum arm_perf_pmu_ids id;
 	enum arm_pmu_type type;
 	cpumask_t	active_irqs;
@@ -84,6 +85,8 @@ struct arm_pmu {
 	struct cpu_hw_events	*(*get_hw_events)(void);
 };
 
+#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 *armpmu;
 
@@ -193,6 +196,7 @@ armpmu_event_set_period(struct perf_event *event,
 			struct hw_perf_event *hwc,
 			int idx)
 {
+	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 	s64 left = local64_read(&hwc->period_left);
 	s64 period = hwc->sample_period;
 	int ret = 0;
@@ -228,6 +232,7 @@ armpmu_event_update(struct perf_event *event,
 		    struct hw_perf_event *hwc,
 		    int idx, int overflow)
 {
+	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 	u64 delta, prev_raw_count, new_raw_count;
 
 again:
@@ -267,6 +272,7 @@ armpmu_read(struct perf_event *event)
 static void
 armpmu_stop(struct perf_event *event, int flags)
 {
+	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 	struct hw_perf_event *hwc = &event->hw;
 
 	/*
@@ -284,6 +290,7 @@ armpmu_stop(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;
 
 	/*
@@ -308,6 +315,7 @@ armpmu_start(struct perf_event *event, int flags)
 static void
 armpmu_del(struct perf_event *event, int flags)
 {
+	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 	struct cpu_hw_events *cpuc = armpmu->get_hw_events();
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
@@ -324,6 +332,7 @@ armpmu_del(struct perf_event *event, int flags)
 static int
 armpmu_add(struct perf_event *event, int flags)
 {
+	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 	struct cpu_hw_events *cpuc = armpmu->get_hw_events();
 	struct hw_perf_event *hwc = &event->hw;
 	int idx;
@@ -358,12 +367,11 @@ out:
 	return err;
 }
 
-static struct pmu pmu;
-
 static int
 validate_event(struct cpu_hw_events *cpuc,
 	       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;
 
@@ -397,6 +405,7 @@ validate_group(struct perf_event *event)
 
 static irqreturn_t armpmu_platform_irq(int irq, void *dev)
 {
+	struct arm_pmu *armpmu = (struct arm_pmu *) dev;
 	struct platform_device *plat_device = armpmu->plat_device;
 	struct arm_pmu_platdata *plat = dev_get_platdata(&plat_device->dev);
 
@@ -404,7 +413,7 @@ static irqreturn_t armpmu_platform_irq(int irq, void *dev)
 }
 
 static void
-armpmu_release_hardware(void)
+armpmu_release_hardware(struct arm_pmu *armpmu)
 {
 	int i, irq, irqs;
 	struct platform_device *pmu_device = armpmu->plat_device;
@@ -416,14 +425,14 @@ armpmu_release_hardware(void)
 			continue;
 		irq = platform_get_irq(pmu_device, i);
 		if (irq >= 0)
-			free_irq(irq, NULL);
+			free_irq(irq, armpmu);
 	}
 
 	release_pmu(armpmu->type);
 }
 
 static int
-armpmu_reserve_hardware(void)
+armpmu_reserve_hardware(struct arm_pmu *armpmu)
 {
 	struct arm_pmu_platdata *plat;
 	irq_handler_t handle_irq;
@@ -467,11 +476,11 @@ armpmu_reserve_hardware(void)
 
 		err = request_irq(irq, handle_irq,
 				  IRQF_DISABLED | IRQF_NOBALANCING,
-				  "arm-pmu", NULL);
+				  "arm-pmu", armpmu);
 		if (err) {
 			pr_err("unable to request IRQ%d for ARM PMU counters\n",
 				irq);
-			armpmu_release_hardware();
+			armpmu_release_hardware(armpmu);
 			return err;
 		}
 
@@ -484,11 +493,12 @@ armpmu_reserve_hardware(void)
 static void
 hw_perf_event_destroy(struct perf_event *event)
 {
+	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 	atomic_t *active_events	 = &armpmu->active_events;
 	struct mutex *pmu_reserve_mutex = &armpmu->reserve_mutex;
 
 	if (atomic_dec_and_mutex_lock(active_events, pmu_reserve_mutex)) {
-		armpmu_release_hardware();
+		armpmu_release_hardware(armpmu);
 		mutex_unlock(pmu_reserve_mutex);
 	}
 }
@@ -503,6 +513,7 @@ event_requires_mode_exclusion(struct perf_event_attr *attr)
 static int
 __hw_perf_event_init(struct perf_event *event)
 {
+	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 	struct hw_perf_event *hwc = &event->hw;
 	int mapping, err;
 
@@ -559,6 +570,7 @@ __hw_perf_event_init(struct perf_event *event)
 
 static int armpmu_event_init(struct perf_event *event)
 {
+	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
 	int err = 0;
 	atomic_t *active_events = &armpmu->active_events;
 
@@ -570,7 +582,7 @@ static int armpmu_event_init(struct perf_event *event)
 	if (!atomic_inc_not_zero(active_events)) {
 		mutex_lock(&armpmu->reserve_mutex);
 		if (atomic_read(active_events) == 0)
-			err = armpmu_reserve_hardware();
+			err = armpmu_reserve_hardware(armpmu);
 
 		if (!err)
 			atomic_inc(active_events);
@@ -589,6 +601,7 @@ static int armpmu_event_init(struct perf_event *event)
 
 static void armpmu_enable(struct pmu *pmu)
 {
+	struct arm_pmu *armpmu = to_arm_pmu(pmu);
 	/* Enable all of the perf events on hardware. */
 	int idx, enabled = 0;
 	struct cpu_hw_events *cpuc = armpmu->get_hw_events();
@@ -609,24 +622,31 @@ static void armpmu_enable(struct pmu *pmu)
 
 static void armpmu_disable(struct pmu *pmu)
 {
+	struct arm_pmu *armpmu = to_arm_pmu(pmu);
 	armpmu->stop();
 }
 
-static struct pmu pmu = {
-	.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,
-};
-
 static void __init armpmu_init(struct arm_pmu *armpmu)
 {
 	atomic_set(&armpmu->active_events, 0);
 	mutex_init(&armpmu->reserve_mutex);
+
+	armpmu->pmu = (struct pmu) {
+		.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,
+	};
+}
+
+static int __init armpmu_register(struct arm_pmu *armpmu, char *name, int type)
+{
+	armpmu_init(armpmu);
+	return perf_pmu_register(&armpmu->pmu, name, type);
 }
 
 /* Include the PMU-specific implementations. */
@@ -751,8 +771,7 @@ init_hw_perf_events(void)
 		pr_info("enabled with %s PMU driver, %d counters available\n",
 			armpmu->name, armpmu->num_events);
 		cpu_pmu_init(armpmu);
-		armpmu_init(armpmu);
-		perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
+		armpmu_register(armpmu, "cpu", PERF_TYPE_RAW);
 	} else {
 		pr_info("no hardware support available\n");
 	}
-- 
1.7.0.4

^ permalink raw reply related	[flat|nested] 18+ messages in thread
end of thread, other threads:[~2011-08-17 14:12 UTC | newest]

Thread overview: 18+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-08-15 13:55 [RFC PATCH 00/15] ARM: perf: support multiple PMUs Mark Rutland
2011-08-15 13:55 ` [RFC PATCH 01/15] perf: provide PMU when initing events Mark Rutland
2011-08-15 13:55 ` [RFC PATCH 02/15] ARM: perf: only register a CPU PMU when present Mark Rutland
2011-08-15 13:55 ` [RFC PATCH 03/15] ARM: perf: clean up event group validation Mark Rutland
2011-08-15 13:55 ` [RFC PATCH 04/15] ARM: perf: remove active_mask Mark Rutland
2011-08-15 13:55 ` [RFC PATCH 05/15] ARM: perf: move active_events into struct arm_pmu Mark Rutland
2011-08-15 13:55 ` [RFC PATCH 06/15] ARM: perf: move platform device to " Mark Rutland
2011-08-15 13:55 ` [RFC PATCH 07/15] ARM: perf: indirect access to cpu_hw_events Mark Rutland
2011-08-15 13:55 ` [RFC PATCH 08/15] ARM: perf: remove unnecessary armpmu->stop Mark Rutland
2011-08-15 13:55 ` [RFC PATCH 09/15] ARM: perf: lock PMU registers per-CPU Mark Rutland
2011-08-15 13:55 ` [RFC PATCH 10/15] ARM: perf: add type field to struct arm_pmu Mark Rutland
2011-08-15 13:55 ` [RFC PATCH 11/15] ARM: perf: refactor event mapping Mark Rutland
2011-08-15 13:55 ` [RFC PATCH 12/15] ARM: perf: add support for multiple PMUs Mark Rutland
2011-08-15 13:55 ` [RFC PATCH 13/15] ARM: perf: remove event limit from pmu_hw_events Mark Rutland
2011-08-15 13:55 ` [RFC PATCH 14/15] ARM: perf: remove cpu-related misnomers Mark Rutland
2011-08-15 13:55 ` [RFC PATCH 15/15] ARM: perf: move arm_pmu into <asm/pmu.h> Mark Rutland
2011-08-17 14:12 ` [RFC PATCH 00/15] ARM: perf: support multiple PMUs Jamie Iles
  -- strict thread matches above, loose matches on Subject: below --
2011-04-28 15:27 [RFC PATCH 12/15] ARM: perf: add support for " Mark Rutland

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