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@xxxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
---
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 dd9acc95ebc0..488bda0646ec 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
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