Add support for irq registration when pmu interrupt is percpu.

Signed-off-by: Vinayak Kale <redacted>
Signed-off-by: Tuan Phan <redacted>
---
 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)) {

+				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)) {