| From ad3c5d9224ffcd7b2e083f03441c6188d2bbef67 Mon Sep 17 00:00:00 2001 |
| From: Thomas Gleixner <tglx@linutronix.de> |
| Date: Tue, 18 May 2021 11:17:28 +0200 |
| Subject: [PATCH 01/14] perf/arm-cmn: 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 <tglx@linutronix.de> |
| |
| Link: https://lore.kernel.org/r/20210518093118.277228577@linutronix.de |
| Signed-off-by: Will Deacon <will@kernel.org> |
| |
| Upstream-Status: Backport [https://lore.kernel.org/r/20210518093118.277228577@linutronix.de] |
| Signed-off-by: Rupinderjit Singh <rupinderjit.singh@arm.com> |
| --- |
| drivers/perf/arm-cmn.c | 9 ++------- |
| 1 file changed, 2 insertions(+), 7 deletions(-) |
| |
| diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c |
| index 46defb1dcf86..38fa6f89d0bc 100644 |
| --- a/drivers/perf/arm-cmn.c |
| +++ b/drivers/perf/arm-cmn.c |
| @@ -1162,7 +1162,7 @@ static int arm_cmn_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node) |
| |
| perf_pmu_migrate_context(&cmn->pmu, cpu, target); |
| for (i = 0; i < cmn->num_dtcs; i++) |
| - irq_set_affinity_hint(cmn->dtc[i].irq, cpumask_of(target)); |
| + irq_set_affinity(cmn->dtc[i].irq, cpumask_of(target)); |
| cmn->cpu = target; |
| return 0; |
| } |
| @@ -1222,7 +1222,7 @@ static int arm_cmn_init_irqs(struct arm_cmn *cmn) |
| if (err) |
| return err; |
| |
| - err = irq_set_affinity_hint(irq, cpumask_of(cmn->cpu)); |
| + err = irq_set_affinity(irq, cpumask_of(cmn->cpu)); |
| if (err) |
| return err; |
| next: |
| @@ -1568,16 +1568,11 @@ static int arm_cmn_probe(struct platform_device *pdev) |
| static int arm_cmn_remove(struct platform_device *pdev) |
| { |
| struct arm_cmn *cmn = platform_get_drvdata(pdev); |
| - int i; |
| |
| writel_relaxed(0, cmn->dtc[0].base + CMN_DT_DTC_CTL); |
| |
| perf_pmu_unregister(&cmn->pmu); |
| cpuhp_state_remove_instance(arm_cmn_hp_state, &cmn->cpuhp_node); |
| - |
| - for (i = 0; i < cmn->num_dtcs; i++) |
| - irq_set_affinity_hint(cmn->dtc[i].irq, NULL); |
| - |
| return 0; |
| } |
| |
| -- |
| 2.25.1 |
| |