[PATCH v2 2/3] ARM: pmu: add support for interrupt-affinity property
From: Will Deacon <hidden>
Date: 2015-02-27 19:32:28
Subsystem:
arm pmu profiling and debugging, arm port, performance events subsystem, the rest · Maintainers:
Will Deacon, Mark Rutland, Russell King, Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds
Historically, the PMU devicetree bindings have expected SPIs to be listed in order of *logical* CPU number. This is problematic for bootloaders, especially when the boot CPU (logical ID 0) isn't listed first in the devicetree. This patch adds a new optional property, interrupt-affinity, to the PMU node which allows the interrupt affinity to be described using a list of phandled to CPU nodes, with each entry in the list corresponding to the SPI at the same index in the interrupts property. Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <redacted> --- arch/arm/include/asm/pmu.h | 1 + arch/arm/kernel/perf_event_cpu.c | 69 ++++++++++++++++++++++++++++++++++++---- 2 files changed, 63 insertions(+), 7 deletions(-)
diff --git a/arch/arm/include/asm/pmu.h b/arch/arm/include/asm/pmu.h
index b1596bd59129..675e4ab79f68 100644
--- a/arch/arm/include/asm/pmu.h
+++ b/arch/arm/include/asm/pmu.h@@ -92,6 +92,7 @@ struct pmu_hw_events { struct arm_pmu { struct pmu pmu; cpumask_t active_irqs; + int *irq_affinity; char *name; irqreturn_t (*handle_irq)(int irq_num, void *dev); void (*enable)(struct perf_event *event);
diff --git a/arch/arm/kernel/perf_event_cpu.c b/arch/arm/kernel/perf_event_cpu.c
index 61b53c46edfa..d012bff1bba7 100644
--- a/arch/arm/kernel/perf_event_cpu.c
+++ b/arch/arm/kernel/perf_event_cpu.c@@ -92,11 +92,16 @@ static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu) free_percpu_irq(irq, &hw_events->percpu_pmu); } else { for (i = 0; i < irqs; ++i) { - if (!cpumask_test_and_clear_cpu(i, &cpu_pmu->active_irqs)) + int cpu = i; + + if (cpu_pmu->irq_affinity) + cpu = cpu_pmu->irq_affinity[i]; + + if (!cpumask_test_and_clear_cpu(cpu, &cpu_pmu->active_irqs)) continue; irq = platform_get_irq(pmu_device, i); if (irq >= 0) - free_irq(irq, per_cpu_ptr(&hw_events->percpu_pmu, i)); + free_irq(irq, per_cpu_ptr(&hw_events->percpu_pmu, cpu)); } } }
@@ -128,32 +133,37 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler) on_each_cpu(cpu_pmu_enable_percpu_irq, &irq, 1); } else { for (i = 0; i < irqs; ++i) { + int cpu = i; + err = 0; irq = platform_get_irq(pmu_device, i); if (irq < 0) continue; + if (cpu_pmu->irq_affinity) + cpu = cpu_pmu->irq_affinity[i]; + /* * If we have a single PMU interrupt that we can't shift, * assume that we're running on a uniprocessor machine and * continue. Otherwise, continue without this interrupt. */ - if (irq_set_affinity(irq, cpumask_of(i)) && irqs > 1) { + if (irq_set_affinity(irq, cpumask_of(cpu)) && irqs > 1) { pr_warn("unable to set irq affinity (irq=%d, cpu=%u)\n", - irq, i); + irq, cpu); continue; } err = request_irq(irq, handler, IRQF_NOBALANCING | IRQF_NO_THREAD, "arm-pmu", - per_cpu_ptr(&hw_events->percpu_pmu, i)); + per_cpu_ptr(&hw_events->percpu_pmu, cpu)); if (err) { pr_err("unable to request IRQ%d for ARM PMU counters\n", irq); return err; } - cpumask_set_cpu(i, &cpu_pmu->active_irqs); + cpumask_set_cpu(cpu, &cpu_pmu->active_irqs); } }
@@ -289,6 +299,48 @@ static int probe_current_pmu(struct arm_pmu *pmu) return ret; } +static int of_pmu_irq_cfg(struct platform_device *pdev) +{ + int i; + int *irqs = kcalloc(pdev->num_resources, sizeof(*irqs), GFP_KERNEL); + + if (!irqs) + return -ENOMEM; + + for (i = 0; i < pdev->num_resources; ++i) { + struct device_node *dn; + int cpu = -1; + + dn = of_parse_phandle(pdev->dev.of_node, "interrupt-affinity", + i); + if (!dn) { + pr_warn("Failed to parse interrupt-affinity for idx %d\n", + i); + break; + } + + for_each_possible_cpu(cpu) + if (arch_find_n_match_cpu_physical_id(dn, cpu, NULL)) + break; + + if (cpu == -1) { + pr_warn("Failed to find logical CPU for %s\n", + dn->name); + break; + } + + irqs[i] = cpu; + of_node_put(dn); + } + + if (i == pdev->num_resources) + cpu_pmu->irq_affinity = irqs; + else + kfree(irqs); + + return 0; +} + static int cpu_pmu_device_probe(struct platform_device *pdev) { const struct of_device_id *of_id;
@@ -313,7 +365,10 @@ static int cpu_pmu_device_probe(struct platform_device *pdev) if (node && (of_id = of_match_node(cpu_pmu_of_device_ids, pdev->dev.of_node))) { init_fn = of_id->data; - ret = init_fn(pmu); + + ret = of_pmu_irq_cfg(pdev); + if (!ret) + ret = init_fn(pmu); } else { ret = probe_current_pmu(pmu); }
--
2.1.4