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authorSebastian Andrzej Siewior <bigeasy@linutronix.de>2016-07-13 20:16:24 +0300
committerIngo Molnar <mingo@kernel.org>2016-07-14 10:34:39 +0300
commit28c94843bb873196f704e9a26775b117a32a31ad (patch)
treef9f0ea50cb4acd9815097f93268cd053e9d47ca1 /drivers/bus
parente3cfce17d309a3c914e36ac4b4b26c30045d4274 (diff)
downloadlinux-28c94843bb873196f704e9a26775b117a32a31ad.tar.xz
bus/arm-cci: Convert to hotplug statemachine
Install the callbacks via the state machine and let the core invoke the callbacks on the already online CPUs. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Cc: Andrzej Hajda <a.hajda@samsung.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Olof Johansson <olof@lixom.net> Cc: Pawel Moll <pawel.moll@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Punit Agrawal <punit.agrawal@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Suzuki K. Poulose <suzuki.poulose@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153334.679142601@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/bus')
-rw-r--r--drivers/bus/arm-cci.c53
1 files changed, 23 insertions, 30 deletions
diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
index a49b28378d59..5755907f836f 100644
--- a/drivers/bus/arm-cci.c
+++ b/drivers/bus/arm-cci.c
@@ -144,12 +144,15 @@ struct cci_pmu {
int num_cntrs;
atomic_t active_events;
struct mutex reserve_mutex;
- struct notifier_block cpu_nb;
+ struct list_head entry;
cpumask_t cpus;
};
#define to_cci_pmu(c) (container_of(c, struct cci_pmu, pmu))
+static DEFINE_MUTEX(cci_pmu_mutex);
+static LIST_HEAD(cci_pmu_list);
+
enum cci_models {
#ifdef CONFIG_ARM_CCI400_PMU
CCI400_R0,
@@ -1503,31 +1506,26 @@ static int cci_pmu_init(struct cci_pmu *cci_pmu, struct platform_device *pdev)
return perf_pmu_register(&cci_pmu->pmu, name, -1);
}
-static int cci_pmu_cpu_notifier(struct notifier_block *self,
- unsigned long action, void *hcpu)
+static int cci_pmu_offline_cpu(unsigned int cpu)
{
- struct cci_pmu *cci_pmu = container_of(self,
- struct cci_pmu, cpu_nb);
- unsigned int cpu = (long)hcpu;
+ struct cci_pmu *cci_pmu;
unsigned int target;
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_DOWN_PREPARE:
+ mutex_lock(&cci_pmu_mutex);
+ list_for_each_entry(cci_pmu, &cci_pmu_list, entry) {
if (!cpumask_test_and_clear_cpu(cpu, &cci_pmu->cpus))
- break;
+ continue;
target = cpumask_any_but(cpu_online_mask, cpu);
- if (target >= nr_cpu_ids) // UP, last CPU
- break;
+ if (target >= nr_cpu_ids)
+ continue;
/*
* TODO: migrate context once core races on event->ctx have
* been fixed.
*/
cpumask_set_cpu(target, &cci_pmu->cpus);
- default:
- break;
}
-
- return NOTIFY_OK;
+ mutex_unlock(&cci_pmu_mutex);
+ return 0;
}
static struct cci_pmu_model cci_pmu_models[] = {
@@ -1766,24 +1764,13 @@ static int cci_pmu_probe(struct platform_device *pdev)
atomic_set(&cci_pmu->active_events, 0);
cpumask_set_cpu(smp_processor_id(), &cci_pmu->cpus);
- cci_pmu->cpu_nb = (struct notifier_block) {
- .notifier_call = cci_pmu_cpu_notifier,
- /*
- * to migrate uncore events, our notifier should be executed
- * before perf core's notifier.
- */
- .priority = CPU_PRI_PERF + 1,
- };
-
- ret = register_cpu_notifier(&cci_pmu->cpu_nb);
+ ret = cci_pmu_init(cci_pmu, pdev);
if (ret)
return ret;
- ret = cci_pmu_init(cci_pmu, pdev);
- if (ret) {
- unregister_cpu_notifier(&cci_pmu->cpu_nb);
- return ret;
- }
+ mutex_lock(&cci_pmu_mutex);
+ list_add(&cci_pmu->entry, &cci_pmu_list);
+ mutex_unlock(&cci_pmu_mutex);
pr_info("ARM %s PMU driver probed", cci_pmu->model->name);
return 0;
@@ -1817,6 +1804,12 @@ static int __init cci_platform_init(void)
{
int ret;
+ ret = cpuhp_setup_state_nocalls(CPUHP_AP_PERF_ARM_CCI_ONLINE,
+ "AP_PERF_ARM_CCI_ONLINE", NULL,
+ cci_pmu_offline_cpu);
+ if (ret)
+ return ret;
+
ret = platform_driver_register(&cci_pmu_driver);
if (ret)
return ret;