Commit-ID: 28c94843bb873196f704e9a26775b117a32a31ad Gitweb: http://git.kernel.org/tip/28c94843bb873196f704e9a26775b117a32a31ad Author: Sebastian Andrzej Siewior <bige...@linutronix.de> AuthorDate: Wed, 13 Jul 2016 17:16:24 +0000 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Thu, 14 Jul 2016 09:34:39 +0200
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 <bige...@linutronix.de> Signed-off-by: Anna-Maria Gleixner <anna-ma...@linutronix.de> Cc: Andrzej Hajda <a.ha...@samsung.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Mark Rutland <mark.rutl...@arm.com> Cc: Olof Johansson <o...@lixom.net> Cc: Pawel Moll <pawel.m...@arm.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Punit Agrawal <punit.agra...@arm.com> Cc: Suzuki K Poulose <suzuki.poul...@arm.com> Cc: Suzuki K. Poulose <suzuki.poul...@arm.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Will Deacon <will.dea...@arm.com> Cc: r...@linutronix.de Link: http://lkml.kernel.org/r/20160713153334.679142...@linutronix.de Signed-off-by: Ingo Molnar <mi...@kernel.org> --- drivers/bus/arm-cci.c | 53 ++++++++++++++++++++-------------------------- include/linux/cpuhotplug.h | 1 + 2 files changed, 24 insertions(+), 30 deletions(-) diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c index a49b283..5755907f 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; diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 16ab417..0f2f727 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -45,6 +45,7 @@ enum cpuhp_state { CPUHP_AP_PERF_X86_CSTATE_ONLINE, CPUHP_AP_PERF_S390_CF_ONLINE, CPUHP_AP_PERF_S390_SF_ONLINE, + CPUHP_AP_PERF_ARM_CCI_ONLINE, CPUHP_AP_NOTIFY_ONLINE, CPUHP_AP_ONLINE_DYN, CPUHP_AP_ONLINE_DYN_END = CPUHP_AP_ONLINE_DYN + 30,
