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ARM: 6064/1: pmu: register IRQs at runtime

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The current PMU infrastructure for ARM requires that the IRQs for the PMU
device are fixed at compile time and are selected based on the ARCH_ or MACH_ flags. This has the disadvantage of tying the Kernel down to a
particular board as far as profiling is concerned.

This patch replaces the compile-time IRQ registration with a runtime mechanism which allows the IRQs to be registered with the framework as
a platform_device.

A further advantage of this change is that there is scope for registering
different types of performance counters in the future by changing the id
of the platform_device and attaching different resources to it.

Acked-by: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Will Deacon
2010-04-29 17:13:24 +01:00
committed by Russell King
parent c39e52a793
commit 49c006b937
3 changed files with 128 additions and 82 deletions
Download Patch File Download Diff File Expand all files Collapse all files

52
arch/arm/kernel/perf_event.c
View File

@@ -17,6 +17,7 @@
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/perf_event.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
@@ -26,7 +27,7 @@
#include <asm/pmu.h>
#include <asm/stacktrace.h>
static const struct pmu_irqs *pmu_irqs;
static struct platform_device *pmu_device;
/*
* Hardware lock to serialize accesses to PMU registers. Needed for the
@@ -314,38 +315,44 @@ validate_group(struct perf_event *event)
static int
armpmu_reserve_hardware(void)
{
int i;
int err;
int i, err = -ENODEV, irq;
pmu_irqs = reserve_pmu();
if (IS_ERR(pmu_irqs)) {
pmu_device = reserve_pmu(ARM_PMU_DEVICE_CPU);
if (IS_ERR(pmu_device)) {
pr_warning("unable to reserve pmu\n");
return PTR_ERR(pmu_irqs);
return PTR_ERR(pmu_device);
}
init_pmu();
init_pmu(ARM_PMU_DEVICE_CPU);
if (pmu_irqs->num_irqs < 1) {
if (pmu_device->num_resources < 1) {
pr_err("no irqs for PMUs defined\n");
return -ENODEV;
}
for (i = 0; i < pmu_irqs->num_irqs; ++i) {
err = request_irq(pmu_irqs->irqs[i], armpmu->handle_irq,
for (i = 0; i < pmu_device->num_resources; ++i) {
irq = platform_get_irq(pmu_device, i);
if (irq < 0)
continue;
err = request_irq(irq, armpmu->handle_irq,
IRQF_DISABLED | IRQF_NOBALANCING,
"armpmu", NULL);
if (err) {
pr_warning("unable to request IRQ%d for ARM "
"perf counters\n", pmu_irqs->irqs[i]);
pr_warning("unable to request IRQ%d for ARM perf "
"counters\n", irq);
break;
}
}
if (err) {
for (i = i - 1; i >= 0; --i)
free_irq(pmu_irqs->irqs[i], NULL);
release_pmu(pmu_irqs);
pmu_irqs = NULL;
for (i = i - 1; i >= 0; --i) {
irq = platform_get_irq(pmu_device, i);
if (irq >= 0)
free_irq(irq, NULL);
}
release_pmu(pmu_device);
pmu_device = NULL;
}
return err;
@@ -354,14 +361,17 @@ armpmu_reserve_hardware(void)
static void
armpmu_release_hardware(void)
{
int i;
int i, irq;
for (i = pmu_irqs->num_irqs - 1; i >= 0; --i)
free_irq(pmu_irqs->irqs[i], NULL);
for (i = pmu_device->num_resources - 1; i >= 0; --i) {
irq = platform_get_irq(pmu_device, i);
if (irq >= 0)
free_irq(irq, NULL);
}
armpmu->stop();
release_pmu(pmu_irqs);
pmu_irqs = NULL;
release_pmu(pmu_device);
pmu_device = NULL;
}
static atomic_t active_events = ATOMIC_INIT(0);