From 54b350fa8e965dc59622698e2a18d6bf73944bf4 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Mon, 20 Oct 2025 13:29:35 +0100 Subject: [PATCH] perf: arm_pmu: Request specific affinities for per CPU NMIs/interrupts Let the PMU driver request both NMIs and normal interrupts with an affinity mask matching the PMU affinity. Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier Signed-off-by: Thomas Gleixner Tested-by: Will Deacon Link: https://patch.msgid.link/20251020122944.3074811-19-maz@kernel.org --- drivers/perf/arm_pmu.c | 44 +++++++++++++++++++-------------- drivers/perf/arm_pmu_acpi.c | 2 +- drivers/perf/arm_pmu_platform.c | 4 +-- include/linux/perf/arm_pmu.h | 4 +-- 4 files changed, 31 insertions(+), 23 deletions(-) diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index 22c601b46c858..959ceb3d1f556 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -26,7 +26,8 @@ #include -static int armpmu_count_irq_users(const int irq); +static int armpmu_count_irq_users(const struct cpumask *affinity, + const int irq); struct pmu_irq_ops { void (*enable_pmuirq)(unsigned int irq); @@ -64,7 +65,9 @@ static void armpmu_enable_percpu_pmuirq(unsigned int irq) static void armpmu_free_percpu_pmuirq(unsigned int irq, int cpu, void __percpu *devid) { - if (armpmu_count_irq_users(irq) == 1) + struct arm_pmu *armpmu = *per_cpu_ptr((void * __percpu *)devid, cpu); + + if (armpmu_count_irq_users(&armpmu->supported_cpus, irq) == 1) free_percpu_irq(irq, devid); } @@ -89,7 +92,9 @@ static void armpmu_disable_percpu_pmunmi(unsigned int irq) static void armpmu_free_percpu_pmunmi(unsigned int irq, int cpu, void __percpu *devid) { - if (armpmu_count_irq_users(irq) == 1) + struct arm_pmu *armpmu = *per_cpu_ptr((void * __percpu *)devid, cpu); + + if (armpmu_count_irq_users(&armpmu->supported_cpus, irq) == 1) free_percpu_nmi(irq, devid); } @@ -580,11 +585,11 @@ static const struct attribute_group armpmu_common_attr_group = { .attrs = armpmu_common_attrs, }; -static int armpmu_count_irq_users(const int irq) +static int armpmu_count_irq_users(const struct cpumask *affinity, const int irq) { int cpu, count = 0; - for_each_possible_cpu(cpu) { + for_each_cpu(cpu, affinity) { if (per_cpu(cpu_irq, cpu) == irq) count++; } @@ -592,12 +597,13 @@ static int armpmu_count_irq_users(const int irq) return count; } -static const struct pmu_irq_ops *armpmu_find_irq_ops(int irq) +static const struct pmu_irq_ops * +armpmu_find_irq_ops(const struct cpumask *affinity, int irq) { const struct pmu_irq_ops *ops = NULL; int cpu; - for_each_possible_cpu(cpu) { + for_each_cpu(cpu, affinity) { if (per_cpu(cpu_irq, cpu) != irq) continue; @@ -609,22 +615,25 @@ static const struct pmu_irq_ops *armpmu_find_irq_ops(int irq) return ops; } -void armpmu_free_irq(int irq, int cpu) +void armpmu_free_irq(struct arm_pmu * __percpu *armpmu, int irq, int cpu) { if (per_cpu(cpu_irq, cpu) == 0) return; if (WARN_ON(irq != per_cpu(cpu_irq, cpu))) return; - per_cpu(cpu_irq_ops, cpu)->free_pmuirq(irq, cpu, &cpu_armpmu); + per_cpu(cpu_irq_ops, cpu)->free_pmuirq(irq, cpu, armpmu); per_cpu(cpu_irq, cpu) = 0; per_cpu(cpu_irq_ops, cpu) = NULL; } -int armpmu_request_irq(int irq, int cpu) +int armpmu_request_irq(struct arm_pmu * __percpu *pcpu_armpmu, int irq, int cpu) { int err = 0; + struct arm_pmu **armpmu = per_cpu_ptr(pcpu_armpmu, cpu); + const struct cpumask *affinity = *armpmu ? &(*armpmu)->supported_cpus : + cpu_possible_mask; /* ACPI */ const irq_handler_t handler = armpmu_dispatch_irq; const struct pmu_irq_ops *irq_ops; @@ -646,25 +655,24 @@ int armpmu_request_irq(int irq, int cpu) IRQF_NOBALANCING | IRQF_NO_AUTOEN | IRQF_NO_THREAD; - err = request_nmi(irq, handler, irq_flags, "arm-pmu", - per_cpu_ptr(&cpu_armpmu, cpu)); + err = request_nmi(irq, handler, irq_flags, "arm-pmu", armpmu); /* If cannot get an NMI, get a normal interrupt */ if (err) { err = request_irq(irq, handler, irq_flags, "arm-pmu", - per_cpu_ptr(&cpu_armpmu, cpu)); + armpmu); irq_ops = &pmuirq_ops; } else { has_nmi = true; irq_ops = &pmunmi_ops; } - } else if (armpmu_count_irq_users(irq) == 0) { - err = request_percpu_nmi(irq, handler, "arm-pmu", NULL, &cpu_armpmu); + } else if (armpmu_count_irq_users(affinity, irq) == 0) { + err = request_percpu_nmi(irq, handler, "arm-pmu", affinity, pcpu_armpmu); /* If cannot get an NMI, get a normal interrupt */ if (err) { - err = request_percpu_irq(irq, handler, "arm-pmu", - &cpu_armpmu); + err = request_percpu_irq_affinity(irq, handler, "arm-pmu", + affinity, pcpu_armpmu); irq_ops = &percpu_pmuirq_ops; } else { has_nmi = true; @@ -672,7 +680,7 @@ int armpmu_request_irq(int irq, int cpu) } } else { /* Per cpudevid irq was already requested by another CPU */ - irq_ops = armpmu_find_irq_ops(irq); + irq_ops = armpmu_find_irq_ops(affinity, irq); if (WARN_ON(!irq_ops)) err = -EINVAL; diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c index 05dda19c5359a..e80f76d95e68b 100644 --- a/drivers/perf/arm_pmu_acpi.c +++ b/drivers/perf/arm_pmu_acpi.c @@ -218,7 +218,7 @@ static int arm_pmu_acpi_parse_irqs(void) * them with their PMUs. */ per_cpu(pmu_irqs, cpu) = irq; - err = armpmu_request_irq(irq, cpu); + err = armpmu_request_irq(&probed_pmus, irq, cpu); if (err) goto out_err; } diff --git a/drivers/perf/arm_pmu_platform.c b/drivers/perf/arm_pmu_platform.c index 9c0494d8a867a..1c9e50a132015 100644 --- a/drivers/perf/arm_pmu_platform.c +++ b/drivers/perf/arm_pmu_platform.c @@ -165,7 +165,7 @@ static int armpmu_request_irqs(struct arm_pmu *armpmu) if (!irq) continue; - err = armpmu_request_irq(irq, cpu); + err = armpmu_request_irq(&hw_events->percpu_pmu, irq, cpu); if (err) break; } @@ -181,7 +181,7 @@ static void armpmu_free_irqs(struct arm_pmu *armpmu) for_each_cpu(cpu, &armpmu->supported_cpus) { int irq = per_cpu(hw_events->irq, cpu); - armpmu_free_irq(irq, cpu); + armpmu_free_irq(&hw_events->percpu_pmu, irq, cpu); } } diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h index 93c9a26492fcf..6690bd77aa4ee 100644 --- a/include/linux/perf/arm_pmu.h +++ b/include/linux/perf/arm_pmu.h @@ -190,8 +190,8 @@ bool arm_pmu_irq_is_nmi(void); struct arm_pmu *armpmu_alloc(void); void armpmu_free(struct arm_pmu *pmu); int armpmu_register(struct arm_pmu *pmu); -int armpmu_request_irq(int irq, int cpu); -void armpmu_free_irq(int irq, int cpu); +int armpmu_request_irq(struct arm_pmu * __percpu *armpmu, int irq, int cpu); +void armpmu_free_irq(struct arm_pmu * __percpu *armpmu, int irq, int cpu); #define ARMV8_PMU_PDEV_NAME "armv8-pmu" -- 2.47.3