perf/smmuv3: Don't cast parameter in bit operations

While in this particular case it would not be a (critical) issue,
the pattern itself is bad and error prone in case somebody blindly
copies to their code.

Don't cast parameter to unsigned long pointer in the bit operations.
Instead copy to a local variable on stack of a proper type and use.

Note, new compilers might warn on this line for potential outbound access.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20220209184758.56578-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Will Deacon <will@kernel.org>

Author: andy-shev

drivers/perf/arm_smmuv3_pmu.c

@@ -654,6 +654,7 @@ static int smmu_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
 static irqreturn_t smmu_pmu_handle_irq(int irq_num, void *data)
 {
 	struct smmu_pmu *smmu_pmu = data;
+	DECLARE_BITMAP(ovs, BITS_PER_TYPE(u64));
 	u64 ovsr;
 	unsigned int idx;
 
@@ -663,7 +664,8 @@ static irqreturn_t smmu_pmu_handle_irq(int irq_num, void *data)
 
 	writeq(ovsr, smmu_pmu->reloc_base + SMMU_PMCG_OVSCLR0);
 
-	for_each_set_bit(idx, (unsigned long *)&ovsr, smmu_pmu->num_counters) {
+	bitmap_from_u64(ovs, ovsr);
+	for_each_set_bit(idx, ovs, smmu_pmu->num_counters) {
 		struct perf_event *event = smmu_pmu->events[idx];
 		struct hw_perf_event *hwc;