[patch 23/66] xtensa: perf: Convert the hotplug notifier to state machine callbacks
From: Anna-Maria Gleixner <anna-maria@linutronix.de>
Date: 2016-07-11 12:43:57
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> 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> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: linux-xtensa@linux-xtensa.org Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> --- arch/xtensa/kernel/perf_event.c | 26 +++++++++----------------- 1 file changed, 9 insertions(+), 17 deletions(-)
--- a/arch/xtensa/kernel/perf_event.c
+++ b/arch/xtensa/kernel/perf_event.c@@ -404,7 +404,7 @@ static struct pmu xtensa_pmu = { .read = xtensa_pmu_read, }; -static void xtensa_pmu_setup(void) +static int xtensa_pmu_setup(int cpu) { unsigned i;
@@ -413,21 +413,7 @@ static void xtensa_pmu_setup(void) set_er(0, XTENSA_PMU_PMCTRL(i)); set_er(get_er(XTENSA_PMU_PMSTAT(i)), XTENSA_PMU_PMSTAT(i)); } -} - -static int xtensa_pmu_notifier(struct notifier_block *self, - unsigned long action, void *data) -{ - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_STARTING: - xtensa_pmu_setup(); - break; - - default: - break; - } - - return NOTIFY_OK; + return 0; } static int __init xtensa_pmu_init(void)
@@ -435,7 +421,13 @@ static int __init xtensa_pmu_init(void) int ret; int irq = irq_create_mapping(NULL, XCHAL_PROFILING_INTERRUPT); - perf_cpu_notifier(xtensa_pmu_notifier); + ret = cpuhp_setup_state(CPUHP_AP_PERF_XTENSA_STARTING, + "AP_PERF_XTENSA_STARTING", xtensa_pmu_setup, + NULL); + if (ret) { + pr_err("xtensa_pmu: failed to register CPU-hotplug.\n"); + return ret; + } #if XTENSA_FAKE_NMI enable_irq(irq); #else