arm64: pmu: add support for interrupt-affinity property

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 <will.deacon@arm.com>
This commit is contained in:
Will Deacon 2015-03-06 11:54:10 +00:00
parent 71bbf038ea
commit d5efd9cc9c
2 changed files with 54 additions and 4 deletions
arch/arm64
include/asm
kernel

View File

@ -44,6 +44,7 @@ struct pmu_hw_events {
struct arm_pmu {
struct pmu pmu;
cpumask_t active_irqs;
int *irq_affinity;
const char *name;
irqreturn_t (*handle_irq)(int irq_num, void *dev);
void (*enable)(struct hw_perf_event *evt, int idx);

View File

@ -25,8 +25,10 @@
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/of.h>
#include <linux/perf_event.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
@ -405,7 +407,12 @@ armpmu_release_hardware(struct arm_pmu *armpmu)
free_percpu_irq(irq, &cpu_hw_events);
} else {
for (i = 0; i < irqs; ++i) {
if (!cpumask_test_and_clear_cpu(i, &armpmu->active_irqs))
int cpu = i;
if (armpmu->irq_affinity)
cpu = armpmu->irq_affinity[i];
if (!cpumask_test_and_clear_cpu(cpu, &armpmu->active_irqs))
continue;
irq = platform_get_irq(pmu_device, i);
if (irq > 0)
@ -459,19 +466,24 @@ armpmu_reserve_hardware(struct arm_pmu *armpmu)
on_each_cpu(armpmu_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 (armpmu->irq_affinity)
cpu = armpmu->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_warning("unable to set irq affinity (irq=%d, cpu=%u)\n",
irq, i);
irq, cpu);
continue;
}
@ -485,7 +497,7 @@ armpmu_reserve_hardware(struct arm_pmu *armpmu)
return err;
}
cpumask_set_cpu(i, &armpmu->active_irqs);
cpumask_set_cpu(cpu, &armpmu->active_irqs);
}
}
@ -1298,9 +1310,46 @@ static const struct of_device_id armpmu_of_device_ids[] = {
static int armpmu_device_probe(struct platform_device *pdev)
{
int i, *irqs;
if (!cpu_pmu)
return -ENODEV;
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;
dn = of_parse_phandle(pdev->dev.of_node, "interrupt-affinity",
i);
if (!dn) {
pr_warn("Failed to parse %s/interrupt-affinity[%d]\n",
of_node_full_name(dn), i);
break;
}
for_each_possible_cpu(cpu)
if (arch_find_n_match_cpu_physical_id(dn, cpu, NULL))
break;
of_node_put(dn);
if (cpu >= nr_cpu_ids) {
pr_warn("Failed to find logical CPU for %s\n",
dn->name);
break;
}
irqs[i] = cpu;
}
if (i == pdev->num_resources)
cpu_pmu->irq_affinity = irqs;
else
kfree(irqs);
cpu_pmu->plat_device = pdev;
return 0;
}