ARM: perf: move irq registration into pmu implementation

This patch moves the CPU-specific IRQ registration and parsing code into
the CPU PMU backend. This is required because a PMU may have more than
one interrupt, which in turn can be either PPI (per-cpu) or SPI
(requiring strict affinity setting at the interrupt distributor).

Signed-off-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
[will: cosmetic edits and reworked interrupt dispatching]
Signed-off-by: Will Deacon <will.deacon@arm.com>

3 files changed, 79 insertions, 61 deletions

diff --git a/arch/arm/include/asm/pmu.h b/arch/arm/include/asm/pmu.h
index a993ad676047..a26170dce02e 100644
--- a/arch/arm/include/asm/pmu.h
+++ b/arch/arm/include/asm/pmu.h
@@ -78,6 +78,8 @@ struct arm_pmu {
         void            (*start)(void);
         void            (*stop)(void);
         void            (*reset)(void *);
+        int             (*request_irq)(irq_handler_t handler);
+        void            (*free_irq)(void);
         int             (*map_event)(struct perf_event *event);
         int             num_events;
         atomic_t        active_events;
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 86fd39937171..93971b1a4f0b 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -297,87 +297,39 @@ validate_group(struct perf_event *event)
         return 0;
 }
 
-static irqreturn_t armpmu_platform_irq(int irq, void *dev)
+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);
 
-        return plat->handle_irq(irq, dev, armpmu->handle_irq);
+        if (plat && plat->handle_irq)
+                return plat->handle_irq(irq, dev, armpmu->handle_irq);
+        else
+                return armpmu->handle_irq(irq, dev);
 }
 
 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());
-
-        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);
-        }
-
-        pm_runtime_put_sync(&pmu_device->dev);
+        armpmu->free_irq();
+        pm_runtime_put_sync(&armpmu->plat_device->dev);
 }
 
 static int
 armpmu_reserve_hardware(struct arm_pmu *armpmu)
 {
-        struct arm_pmu_platdata *plat;
-        irq_handler_t handle_irq;
-        int i, err, irq, irqs;
+        int err;
         struct platform_device *pmu_device = armpmu->plat_device;
 
         if (!pmu_device)
                 return -ENODEV;
 
-        plat = dev_get_platdata(&pmu_device->dev);
-        if (plat && plat->handle_irq)
-                handle_irq = armpmu_platform_irq;
-        else
-                handle_irq = armpmu->handle_irq;
-
-        irqs = min(pmu_device->num_resources, num_possible_cpus());
-        if (irqs < 1) {
-                pr_err("no irqs for PMUs defined\n");
-                return -ENODEV;
-        }
-
         pm_runtime_get_sync(&pmu_device->dev);
-
-        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, handle_irq,
-                                  IRQF_DISABLED | 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);
+        err = armpmu->request_irq(armpmu_dispatch_irq);
+        if (err) {
+                armpmu_release_hardware(armpmu);
+                return err;
         }
 
         return 0;
diff --git a/arch/arm/kernel/perf_event_cpu.c b/arch/arm/kernel/perf_event_cpu.c
index 56ddc989c909..8d7d8d4de9d6 100644
--- a/arch/arm/kernel/perf_event_cpu.c
+++ b/arch/arm/kernel/perf_event_cpu.c
@@ -70,6 +70,67 @@ static struct pmu_hw_events *cpu_pmu_get_cpu_events(void)
         return &__get_cpu_var(cpu_hw_events);
 }
 
+static void cpu_pmu_free_irq(void)
+{
+        int i, irq, irqs;
+        struct platform_device *pmu_device = cpu_pmu->plat_device;
+
+        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);
+        }
+}
+
+static int cpu_pmu_request_irq(irq_handler_t handler)
+{
+        int i, err, irq, irqs;
+        struct platform_device *pmu_device = cpu_pmu->plat_device;
+
+        if (!pmu_device)
+                return -ENODEV;
+
+        irqs = min(pmu_device->num_resources, num_possible_cpus());
+        if (irqs < 1) {
+                pr_err("no irqs for PMUs defined\n");
+                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, "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;
+}
+
 static void __devinit cpu_pmu_init(struct arm_pmu *cpu_pmu)
 {
         int cpu;
@@ -79,7 +140,10 @@ 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 = cpu_pmu_get_cpu_events;
+
+        cpu_pmu->get_hw_events  = cpu_pmu_get_cpu_events;
+        cpu_pmu->request_irq    = cpu_pmu_request_irq;
+        cpu_pmu->free_irq       = cpu_pmu_free_irq;
 
         /* Ensure the PMU has sane values out of reset. */
         if (cpu_pmu && cpu_pmu->reset)