perf: arm_cspmu: Set irq affinitiy only if overflow interrupt is used

BugLink: https://bugs.launchpad.net/bugs/2033685

Don't try to set irq affinity if PMU doesn't have an overflow interrupt.

Fixes: e37dfd6 ("perf: arm_cspmu: Add support for ARM CoreSight PMU driver")
Signed-off-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Link: https://lore.kernel.org/r/20230608203742.3503486-1-ilkka@os.amperecomputing.com
Signed-off-by: Will Deacon <will@kernel.org>
(cherry picked from commit 225d757)
Acked-by: Jamie Nguyen <jamien@nvidia.com>
Acked-by: Brad Figg <bfigg@nvidia.com>
Acked-by: Ian May <ian.may@canonical.com>
Acked-by: Jacob Martin <jacob.martin@canonical.com>

Author: ilkka-koskinen

drivers/perf/arm_cspmu/arm_cspmu.c

@@ -1232,7 +1232,8 @@ static struct platform_driver arm_cspmu_driver = {
 static void arm_cspmu_set_active_cpu(int cpu, struct arm_cspmu *cspmu)
 {
 	cpumask_set_cpu(cpu, &cspmu->active_cpu);
-	WARN_ON(irq_set_affinity(cspmu->irq, &cspmu->active_cpu));
+	if (cspmu->irq)
+		WARN_ON(irq_set_affinity(cspmu->irq, &cspmu->active_cpu));
 }
 
 static int arm_cspmu_cpu_online(unsigned int cpu, struct hlist_node *node)