From 2621054535955fb78ea96b76b279eb481f40fcef Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 18 May 2021 11:17:31 +0200 Subject: perf/arm-smmuv3: Use irq_set_affinity() The driver uses irq_set_affinity_hint() to set the affinity for the PMU interrupts, which relies on the undocumented side effect that this function actually sets the affinity under the hood. Setting an hint is clearly not a guarantee and for these PMU interrupts an affinity hint, which is supposed to guide userspace for setting affinity, is beyond pointless, because the affinity of these interrupts cannot be modified from user space. Aside of that the error checks are bogus because the only error which is returned from irq_set_affinity_hint() is when there is no irq descriptor for the interrupt number, but not when the affinity set fails. That's on purpose because the hint can point to an offline CPU. Replace the mindless abuse with irq_set_affinity(). Signed-off-by: Thomas Gleixner Cc: Will Deacon Cc: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20210518093118.603636289@linutronix.de Signed-off-by: Will Deacon --- drivers/perf/arm_smmuv3_pmu.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) (limited to 'drivers/perf') diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c index ff6fab4bae30..7786ccc6d12f 100644 --- a/drivers/perf/arm_smmuv3_pmu.c +++ b/drivers/perf/arm_smmuv3_pmu.c @@ -628,7 +628,7 @@ static int smmu_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node) perf_pmu_migrate_context(&smmu_pmu->pmu, cpu, target); smmu_pmu->on_cpu = target; - WARN_ON(irq_set_affinity_hint(smmu_pmu->irq, cpumask_of(target))); + WARN_ON(irq_set_affinity(smmu_pmu->irq, cpumask_of(target))); return 0; } @@ -839,15 +839,14 @@ static int smmu_pmu_probe(struct platform_device *pdev) /* Pick one CPU to be the preferred one to use */ smmu_pmu->on_cpu = raw_smp_processor_id(); - WARN_ON(irq_set_affinity_hint(smmu_pmu->irq, - cpumask_of(smmu_pmu->on_cpu))); + WARN_ON(irq_set_affinity(smmu_pmu->irq, cpumask_of(smmu_pmu->on_cpu))); err = cpuhp_state_add_instance_nocalls(cpuhp_state_num, &smmu_pmu->node); if (err) { dev_err(dev, "Error %d registering hotplug, PMU @%pa\n", err, &res_0->start); - goto out_clear_affinity; + return err; } err = perf_pmu_register(&smmu_pmu->pmu, name, -1); @@ -866,8 +865,6 @@ static int smmu_pmu_probe(struct platform_device *pdev) out_unregister: cpuhp_state_remove_instance_nocalls(cpuhp_state_num, &smmu_pmu->node); -out_clear_affinity: - irq_set_affinity_hint(smmu_pmu->irq, NULL); return err; } @@ -877,7 +874,6 @@ static int smmu_pmu_remove(struct platform_device *pdev) perf_pmu_unregister(&smmu_pmu->pmu); cpuhp_state_remove_instance_nocalls(cpuhp_state_num, &smmu_pmu->node); - irq_set_affinity_hint(smmu_pmu->irq, NULL); return 0; } -- cgit v1.2.3