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arm_pmu: note IRQs and PMUs per-cpu

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To support ACPI systems, we need to request IRQs before we know the
associated PMU, and thus we need some percpu variable that the IRQ
handler can find the PMU from.

As we're going to request IRQs without the PMU, we can't rely on the
arm_pmu::active_irqs mask, and similarly need to track requested IRQs
with a percpu variable.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[will: made armpmu_count_irq_users static]
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Mark Rutland 2017-12-12 16:56:06 +00:00 committed by Will Deacon
parent 6de3f79112
commit 84b4be57ae
2 changed files with 52 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

69
drivers/perf/arm_pmu.c
View File

@ -25,6 +25,9 @@
#include <asm/irq_regs.h>
static DEFINE_PER_CPU(struct arm_pmu *, cpu_armpmu);
static DEFINE_PER_CPU(int, cpu_irq);
static int
armpmu_map_cache_event(const unsigned (*cache_map)
[PERF_COUNT_HW_CACHE_MAX]
@ -332,6 +335,8 @@ static irqreturn_t armpmu_dispatch_irq(int irq, void *dev)
* dereference.
*/
armpmu = *(void **)dev;
if (WARN_ON_ONCE(!armpmu))
return IRQ_NONE;
start_clock = sched_clock();
ret = armpmu->handle_irq(irq, armpmu);
@ -517,29 +522,45 @@ int perf_num_counters(void)
}
EXPORT_SYMBOL_GPL(perf_num_counters);
static int armpmu_count_irq_users(const int irq)
{
int cpu, count = 0;
for_each_possible_cpu(cpu) {
if (per_cpu(cpu_irq, cpu) == irq)
count++;
}
return count;
}
void armpmu_free_cpu_irq(int irq, int cpu)
{
if (per_cpu(cpu_irq, cpu) == 0)
return;
if (WARN_ON(irq != per_cpu(cpu_irq, cpu)))
return;
if (!irq_is_percpu_devid(irq))
free_irq(irq, per_cpu_ptr(&cpu_armpmu, cpu));
else if (armpmu_count_irq_users(irq) == 1)
free_percpu_irq(irq, &cpu_armpmu);
per_cpu(cpu_irq, cpu) = 0;
}
void armpmu_free_irq(struct arm_pmu *armpmu, int cpu)
{
struct pmu_hw_events __percpu *hw_events = armpmu->hw_events;
int irq = per_cpu(hw_events->irq, cpu);
if (!cpumask_test_and_clear_cpu(cpu, &armpmu->active_irqs))
return;
if (irq_is_percpu_devid(irq)) {
free_percpu_irq(irq, &hw_events->percpu_pmu);
cpumask_clear(&armpmu->active_irqs);
return;
}
free_irq(irq, per_cpu_ptr(&hw_events->percpu_pmu, cpu));
armpmu_free_cpu_irq(irq, cpu);
}
int armpmu_request_irq(struct arm_pmu *armpmu, int cpu)
int armpmu_request_cpu_irq(int irq, int cpu)
{
int err = 0;
struct pmu_hw_events __percpu *hw_events = armpmu->hw_events;
const irq_handler_t handler = armpmu_dispatch_irq;
int irq = per_cpu(hw_events->irq, cpu);
if (!irq)
return 0;
@ -560,16 +581,16 @@ int armpmu_request_irq(struct arm_pmu *armpmu, int cpu)
irq_set_status_flags(irq, IRQ_NOAUTOEN);
err = request_irq(irq, handler, irq_flags, "arm-pmu",
per_cpu_ptr(&hw_events->percpu_pmu, cpu));
} else if (cpumask_empty(&armpmu->active_irqs)) {
per_cpu_ptr(&cpu_armpmu, cpu));
} else if (armpmu_count_irq_users(irq) == 0) {
err = request_percpu_irq(irq, handler, "arm-pmu",
&hw_events->percpu_pmu);
&cpu_armpmu);
}
if (err)
goto err_out;
cpumask_set_cpu(cpu, &armpmu->active_irqs);
per_cpu(cpu_irq, cpu) = irq;
return 0;
err_out:
@ -577,6 +598,16 @@ err_out:
return err;
}
int armpmu_request_irq(struct arm_pmu *armpmu, int cpu)
{
struct pmu_hw_events __percpu *hw_events = armpmu->hw_events;
int irq = per_cpu(hw_events->irq, cpu);
if (!irq)
return 0;
return armpmu_request_cpu_irq(irq, cpu);
}
static int armpmu_get_cpu_irq(struct arm_pmu *pmu, int cpu)
{
struct pmu_hw_events __percpu *hw_events = pmu->hw_events;
@ -599,6 +630,8 @@ static int arm_perf_starting_cpu(unsigned int cpu, struct hlist_node *node)
if (pmu->reset)
pmu->reset(pmu);
per_cpu(cpu_armpmu, cpu) = pmu;
irq = armpmu_get_cpu_irq(pmu, cpu);
if (irq) {
if (irq_is_percpu_devid(irq))
@ -626,6 +659,8 @@ static int arm_perf_teardown_cpu(unsigned int cpu, struct hlist_node *node)
disable_irq(irq);
}
per_cpu(cpu_armpmu, cpu) = NULL;
return 0;
}

1
include/linux/perf/arm_pmu.h
View File

@ -75,7 +75,6 @@ enum armpmu_attr_groups {
struct arm_pmu {
struct pmu pmu;
cpumask_t active_irqs;
cpumask_t supported_cpus;
char *name;
irqreturn_t (*handle_irq)(int irq_num, void *dev);