arm_pmu: simplify arm_pmu::handle_irq

The arm_pmu::handle_irq() callback has the same prototype as a generic
IRQ handler, taking the IRQ number and a void pointer argument which it
must convert to an arm_pmu pointer.

This means that all arm_pmu::handle_irq() take an IRQ number they never
use, and all must explicitly cast the void pointer to an arm_pmu
pointer.

Instead, let's change arm_pmu::handle_irq to take an arm_pmu pointer,
allowing these casts to be removed. The redundant IRQ number parameter
is also removed.
Suggested-by: NHoeun Ryu <hoeun.ryu@lge.com>
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

arch/arm/kernel/perf_event_v6.c

@@ -303,12 +303,10 @@ static void armv6pmu_enable_event(struct perf_event *event)
 }
 
 static irqreturn_t
-armv6pmu_handle_irq(int irq_num,
-		    void *dev)
+armv6pmu_handle_irq(struct arm_pmu *cpu_pmu)
 {
 	unsigned long pmcr = armv6_pmcr_read();
 	struct perf_sample_data data;
-	struct arm_pmu *cpu_pmu = (struct arm_pmu *)dev;
 	struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events);
 	struct pt_regs *regs;
 	int idx;

arch/arm/kernel/perf_event_v7.c

@@ -946,11 +946,10 @@ static void armv7pmu_disable_event(struct perf_event *event)
 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
 }
 
-static irqreturn_t armv7pmu_handle_irq(int irq_num, void *dev)
+static irqreturn_t armv7pmu_handle_irq(struct arm_pmu *cpu_pmu)
 {
 	u32 pmnc;
 	struct perf_sample_data data;
-	struct arm_pmu *cpu_pmu = (struct arm_pmu *)dev;
 	struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events);
 	struct pt_regs *regs;
 	int idx;

arch/arm/kernel/perf_event_xscale.c

@@ -142,11 +142,10 @@ xscale1_pmnc_counter_has_overflowed(unsigned long pmnc,
 }
 
 static irqreturn_t
-xscale1pmu_handle_irq(int irq_num, void *dev)
+xscale1pmu_handle_irq(struct arm_pmu *cpu_pmu)
 {
 	unsigned long pmnc;
 	struct perf_sample_data data;
-	struct arm_pmu *cpu_pmu = (struct arm_pmu *)dev;
 	struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events);
 	struct pt_regs *regs;
 	int idx;
@@ -489,11 +488,10 @@ xscale2_pmnc_counter_has_overflowed(unsigned long of_flags,
 }
 
 static irqreturn_t
-xscale2pmu_handle_irq(int irq_num, void *dev)
+xscale2pmu_handle_irq(struct arm_pmu *cpu_pmu)
 {
 	unsigned long pmnc, of_flags;
 	struct perf_sample_data data;
-	struct arm_pmu *cpu_pmu = (struct arm_pmu *)dev;
 	struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events);
 	struct pt_regs *regs;
 	int idx;

arch/arm64/kernel/perf_event.c

@@ -670,11 +670,10 @@ static void armv8pmu_disable_event(struct perf_event *event)
 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
 }
 
-static irqreturn_t armv8pmu_handle_irq(int irq_num, void *dev)
+static irqreturn_t armv8pmu_handle_irq(struct arm_pmu *cpu_pmu)
 {
 	u32 pmovsr;
 	struct perf_sample_data data;
-	struct arm_pmu *cpu_pmu = (struct arm_pmu *)dev;
 	struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events);
 	struct pt_regs *regs;
 	int idx;

drivers/perf/arm_pmu.c

@@ -339,7 +339,7 @@ static irqreturn_t armpmu_dispatch_irq(int irq, void *dev)
 		return IRQ_NONE;
 
 	start_clock = sched_clock();
-	ret = armpmu->handle_irq(irq, armpmu);
+	ret = armpmu->handle_irq(armpmu);
 	finish_clock = sched_clock();
 
 	perf_sample_event_took(finish_clock - start_clock);

include/linux/perf/arm_pmu.h

@@ -78,7 +78,7 @@ struct arm_pmu {
 	struct pmu	pmu;
 	cpumask_t	supported_cpus;
 	char		*name;
-	irqreturn_t	(*handle_irq)(int irq_num, void *dev);
+	irqreturn_t	(*handle_irq)(struct arm_pmu *pmu);
 	void		(*enable)(struct perf_event *event);
 	void		(*disable)(struct perf_event *event);
 	int		(*get_event_idx)(struct pmu_hw_events *hw_events,