Vinayak,
On 2013-11-18 13:22, Vinayak Kale wrote:
Add support for irq registration when pmu interrupt is percpu.
Signed-off-by: Vinayak Kale <vk...@apm.com>
Signed-off-by: Tuan Phan <tp...@apm.com>
---
arch/arm64/kernel/perf_event.c | 102
+++++++++++++++++++++++++++++-----------
1 file changed, 74 insertions(+), 28 deletions(-)
diff --git a/arch/arm64/kernel/perf_event.c
b/arch/arm64/kernel/perf_event.c
index cea1594..23475f6 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -22,6 +22,7 @@
#include <linux/bitmap.h>
#include <linux/interrupt.h>
+#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/perf_event.h>
@@ -363,22 +364,51 @@ validate_group(struct perf_event *event)
}
static void
+armpmu_disable_percpu_irq(void *data)
+{
+ struct arm_pmu *armpmu = data;
+ struct platform_device *pmu_device = armpmu->plat_device;
+ int irq = platform_get_irq(pmu_device, 0);
+
+ cpumask_test_and_clear_cpu(smp_processor_id(),
&armpmu->active_irqs);
+ disable_percpu_irq(irq);
+}
+
+static void
armpmu_release_hardware(struct arm_pmu *armpmu)
{
int i, irq, irqs;
struct platform_device *pmu_device = armpmu->plat_device;
- irqs = min(pmu_device->num_resources, num_possible_cpus());
+ irq = platform_get_irq(pmu_device, 0);
- for (i = 0; i < irqs; ++i) {
- if (!cpumask_test_and_clear_cpu(i, &armpmu->active_irqs))
- continue;
- irq = platform_get_irq(pmu_device, i);
- if (irq >= 0)
- free_irq(irq, armpmu);
+ if (irq_to_desc(irq) && irq_is_percpu(irq)) {
Why do you need to check the irq_desc here? It really looks like a
misuse of the API.
Instead, you should check the value of irq itself (it should be
strictly positive).
+ on_each_cpu(armpmu_disable_percpu_irq, armpmu, 1);
+ free_percpu_irq(irq, &cpu_hw_events);
+ } else {
+ irqs = min(pmu_device->num_resources, num_possible_cpus());
+
+ for (i = 0; i < irqs; ++i) {
+ if (!cpumask_test_and_clear_cpu(i,
&armpmu->active_irqs))
+ continue;
+ irq = platform_get_irq(pmu_device, i);
+ if (irq >= 0)
irq == 0 means "no-irq". You should handle it as an error case.
+ free_irq(irq, armpmu);
+ }
}
}
+static void
+armpmu_enable_percpu_irq(void *data)
+{
+ struct arm_pmu *armpmu = data;
+ struct platform_device *pmu_device = armpmu->plat_device;
+ int irq = platform_get_irq(pmu_device, 0);
+
+ enable_percpu_irq(irq, 0);
+ cpumask_set_cpu(smp_processor_id(), &armpmu->active_irqs);
+}
+
static int
armpmu_reserve_hardware(struct arm_pmu *armpmu)
{
@@ -396,34 +426,50 @@ armpmu_reserve_hardware(struct arm_pmu *armpmu)
return -ENODEV;
}
- for (i = 0; i < irqs; ++i) {
- err = 0;
- irq = platform_get_irq(pmu_device, i);
- if (irq < 0)
- continue;
+ irq = platform_get_irq(pmu_device, 0);
- /*
- * 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;
- }
+ if (irq_to_desc(irq) && irq_is_percpu(irq)) {
Same comment about irq_to_desc.
+ err = request_percpu_irq(irq, armpmu->handle_irq,
+ "arm-pmu", &cpu_hw_events);
- err = request_irq(irq, armpmu->handle_irq,
- IRQF_NOBALANCING,
- "arm-pmu", armpmu);
if (err) {
- pr_err("unable to request IRQ%d for ARM PMU counters\n",
- irq);
+ pr_err("unable to request percpu IRQ%d for ARM PMU
counters\n",
+ irq);
armpmu_release_hardware(armpmu);
return err;
}
- cpumask_set_cpu(i, &armpmu->active_irqs);
+ on_each_cpu(armpmu_enable_percpu_irq, armpmu, 1);
+ } else {
+ for (i = 0; i < irqs; ++i) {
+ err = 0;
+ irq = platform_get_irq(pmu_device, i);
+ if (irq < 0)
Same comment about 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, armpmu->handle_irq,
+ IRQF_NOBALANCING,
+ "arm-pmu", armpmu);
+ if (err) {
+ pr_err("unable to request IRQ%d for ARM PMU
counters\n",
+ irq);
+ armpmu_release_hardware(armpmu);
+ return err;
+ }
+
+ cpumask_set_cpu(i, &armpmu->active_irqs);
+ }
}
return 0;
--
Fast, cheap, reliable. Pick two.
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