[patch 49/66] metag: perf: Convert to hotplug state machine
From: Anna-Maria Gleixner <anna-maria@linutronix.de>
Date: 2016-07-11 12:36:47
Install the callbacks via the state machine and let the core invoke the callbacks on the already online CPUs. Signed-off-by: Richard Cochran <redacted> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: James Hogan <redacted> Cc: linux-metag@vger.kernel.org Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> --- arch/metag/kernel/perf/perf_event.c | 26 +++++++------------------- include/linux/cpuhotplug.h | 1 + 2 files changed, 8 insertions(+), 19 deletions(-)
--- a/arch/metag/kernel/perf/perf_event.c
+++ b/arch/metag/kernel/perf/perf_event.c@@ -806,25 +806,16 @@ static struct metag_pmu _metag_pmu = { }; /* PMU CPU hotplug notifier */ -static int metag_pmu_cpu_notify(struct notifier_block *b, unsigned long action, - void *hcpu) +static int metag_pmu_starting_cpu(unsigned int cpu) { - unsigned int cpu = (unsigned int)hcpu; struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu); - if ((action & ~CPU_TASKS_FROZEN) != CPU_STARTING) - return NOTIFY_DONE; - memset(cpuc, 0, sizeof(struct cpu_hw_events)); raw_spin_lock_init(&cpuc->pmu_lock); - return NOTIFY_OK; + return 0; } -static struct notifier_block metag_pmu_notifier = { - .notifier_call = metag_pmu_cpu_notify, -}; - /* PMU Initialisation */ static int __init init_hw_perf_events(void) {
@@ -876,16 +867,13 @@ static int __init init_hw_perf_events(vo metag_out32(0, PERF_COUNT(0)); metag_out32(0, PERF_COUNT(1)); - for_each_possible_cpu(cpu) { - struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu); - - memset(cpuc, 0, sizeof(struct cpu_hw_events)); - raw_spin_lock_init(&cpuc->pmu_lock); - } + cpuhp_setup_state(CPUHP_AP_PERF_METAG_STARTING, + "AP_PERF_METAG_STARTING", metag_pmu_starting_cpu, + NULL); - register_cpu_notifier(&metag_pmu_notifier); ret = perf_pmu_register(&pmu, metag_pmu->name, PERF_TYPE_RAW); -out: + if (ret) + cpuhp_remove_state_nocalls(CPUHP_AP_PERF_METAG_STARTING); return ret; } early_initcall(init_hw_perf_events); --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h
@@ -35,6 +35,7 @@ enum cpuhp_state { CPUHP_AP_PERF_X86_CQM_STARTING, CPUHP_AP_PERF_X86_CSTATE_STARTING, CPUHP_AP_PERF_XTENSA_STARTING, + CPUHP_AP_PERF_METAG_STARTING, CPUHP_AP_ARM_VFP_STARTING, CPUHP_AP_PERF_ARM_STARTING, CPUHP_AP_ARM_ARCH_TIMER_STARTING,