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>

diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c
index c49108a728659ca2df5a129326f390fb63d3569c..00d4c45a8017d7e2632ef51611ac92916bcd1011 100644 (file)
--- a/drivers/perf/arm_smmuv3_pmu.c
+++ b/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;