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: Hoeun Ryu <hoeun.ryu@lge.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index 85a251b..33147aa 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/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;