[PATCH v3 1/7] ARM: perf_event: Support percpu irqs for the CPU PMU
Stephen Boyd
sboyd at codeaurora.org
Fri Feb 7 16:01:19 EST 2014
Some CPU PMUs are wired up with one PPI for all the CPUs instead
of with a different SPI for each CPU. Add support for these
devices.
Signed-off-by: Stephen Boyd <sboyd at codeaurora.org>
---
arch/arm/kernel/perf_event.c | 14 ++++--
arch/arm/kernel/perf_event_cpu.c | 97 ++++++++++++++++++++++++++++------------
2 files changed, 80 insertions(+), 31 deletions(-)
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 789d846a9184..b0c8489018d3 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -16,6 +16,8 @@
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/uaccess.h>
+#include <linux/irq.h>
+#include <linux/irqdesc.h>
#include <asm/irq_regs.h>
#include <asm/pmu.h>
@@ -295,9 +297,15 @@ validate_group(struct perf_event *event)
static irqreturn_t armpmu_dispatch_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);
+ struct arm_pmu *armpmu;
+ struct platform_device *plat_device;
+ struct arm_pmu_platdata *plat;
+
+ if (irq_is_percpu(irq))
+ dev = *(void **)dev;
+ armpmu = dev;
+ plat_device = armpmu->plat_device;
+ plat = dev_get_platdata(&plat_device->dev);
if (plat && plat->handle_irq)
return plat->handle_irq(irq, dev, armpmu->handle_irq);
diff --git a/arch/arm/kernel/perf_event_cpu.c b/arch/arm/kernel/perf_event_cpu.c
index 20d553c9f5e2..6efd8aab15df 100644
--- a/arch/arm/kernel/perf_event_cpu.c
+++ b/arch/arm/kernel/perf_event_cpu.c
@@ -25,6 +25,8 @@
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
+#include <linux/irq.h>
+#include <linux/irqdesc.h>
#include <asm/cputype.h>
#include <asm/irq_regs.h>
@@ -33,6 +35,7 @@
/* Set at runtime when we know what CPU type we are. */
static struct arm_pmu *cpu_pmu;
+static DEFINE_PER_CPU(struct arm_pmu *, percpu_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);
@@ -71,6 +74,26 @@ static struct pmu_hw_events *cpu_pmu_get_cpu_events(void)
return this_cpu_ptr(&cpu_hw_events);
}
+static void cpu_pmu_enable_percpu_irq(void *data)
+{
+ struct arm_pmu *cpu_pmu = data;
+ struct platform_device *pmu_device = cpu_pmu->plat_device;
+ int irq = platform_get_irq(pmu_device, 0);
+
+ enable_percpu_irq(irq, IRQ_TYPE_NONE);
+ cpumask_set_cpu(smp_processor_id(), &cpu_pmu->active_irqs);
+}
+
+static void cpu_pmu_disable_percpu_irq(void *data)
+{
+ struct arm_pmu *cpu_pmu = data;
+ struct platform_device *pmu_device = cpu_pmu->plat_device;
+ int irq = platform_get_irq(pmu_device, 0);
+
+ cpumask_clear_cpu(smp_processor_id(), &cpu_pmu->active_irqs);
+ disable_percpu_irq(irq);
+}
+
static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
{
int i, irq, irqs;
@@ -78,12 +101,18 @@ static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
irqs = min(pmu_device->num_resources, num_possible_cpus());
- for (i = 0; i < irqs; ++i) {
- if (!cpumask_test_and_clear_cpu(i, &cpu_pmu->active_irqs))
- continue;
- irq = platform_get_irq(pmu_device, i);
- if (irq >= 0)
- free_irq(irq, cpu_pmu);
+ irq = platform_get_irq(pmu_device, 0);
+ if (irq >= 0 && irq_is_percpu(irq)) {
+ on_each_cpu(cpu_pmu_disable_percpu_irq, cpu_pmu, 1);
+ free_percpu_irq(irq, &percpu_pmu);
+ } else {
+ for (i = 0; i < irqs; ++i) {
+ if (!cpumask_test_and_clear_cpu(i, &cpu_pmu->active_irqs))
+ continue;
+ irq = platform_get_irq(pmu_device, i);
+ if (irq >= 0)
+ free_irq(irq, cpu_pmu);
+ }
}
}
@@ -101,33 +130,44 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
return -ENODEV;
}
- for (i = 0; i < irqs; ++i) {
- err = 0;
- irq = platform_get_irq(pmu_device, i);
- if (irq < 0)
- continue;
-
- /*
- * If we have a single PMU interrupt that we can't shift,
- * assume that we're running on a uniprocessor machine and
- * continue. Otherwise, continue without this interrupt.
- */
- if (irq_set_affinity(irq, cpumask_of(i)) && irqs > 1) {
- pr_warning("unable to set irq affinity (irq=%d, cpu=%u)\n",
- irq, i);
- continue;
- }
-
- err = request_irq(irq, handler,
- IRQF_NOBALANCING | IRQF_NO_THREAD, "arm-pmu",
- cpu_pmu);
+ irq = platform_get_irq(pmu_device, 0);
+ if (irq >= 0 && irq_is_percpu(irq)) {
+ err = request_percpu_irq(irq, handler, "arm-pmu", &percpu_pmu);
if (err) {
pr_err("unable to request IRQ%d for ARM PMU counters\n",
irq);
return err;
}
-
- cpumask_set_cpu(i, &cpu_pmu->active_irqs);
+ on_each_cpu(cpu_pmu_enable_percpu_irq, cpu_pmu, 1);
+ } else {
+ for (i = 0; i < irqs; ++i) {
+ err = 0;
+ irq = platform_get_irq(pmu_device, i);
+ if (irq < 0)
+ continue;
+
+ /*
+ * If we have a single PMU interrupt that we can't shift,
+ * assume that we're running on a uniprocessor machine and
+ * continue. Otherwise, continue without this interrupt.
+ */
+ if (irq_set_affinity(irq, cpumask_of(i)) && irqs > 1) {
+ pr_warning("unable to set irq affinity (irq=%d, cpu=%u)\n",
+ irq, i);
+ continue;
+ }
+
+ err = request_irq(irq, handler,
+ IRQF_NOBALANCING | IRQF_NO_THREAD, "arm-pmu",
+ cpu_pmu);
+ if (err) {
+ pr_err("unable to request IRQ%d for ARM PMU counters\n",
+ irq);
+ return err;
+ }
+
+ cpumask_set_cpu(i, &cpu_pmu->active_irqs);
+ }
}
return 0;
@@ -141,6 +181,7 @@ static void cpu_pmu_init(struct arm_pmu *cpu_pmu)
events->events = per_cpu(hw_events, cpu);
events->used_mask = per_cpu(used_mask, cpu);
raw_spin_lock_init(&events->pmu_lock);
+ per_cpu(percpu_pmu, cpu) = cpu_pmu;
}
cpu_pmu->get_hw_events = cpu_pmu_get_cpu_events;
--
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