[patch 20/66] sh: perf: Convert the hotplug notifiers to state machine callbacks

[Anna-Maria Gleixner]

From: Thomas Gleixner <t...@linutronix.de>

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: Thomas Gleixner <t...@linutronix.de>
Cc: linux...@vger.kernel.org
Reviewed-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-ma...@linutronix.de>

---
 arch/sh/kernel/perf_event.c |   23 ++++-------------------
 include/linux/cpuhotplug.h  |    1 +
 2 files changed, 5 insertions(+), 19 deletions(-)

--- a/arch/sh/kernel/perf_event.c
+++ b/arch/sh/kernel/perf_event.c
@@ -352,28 +352,12 @@ static struct pmu pmu = {
        .read           = sh_pmu_read,
 };
 
-static void sh_pmu_setup(int cpu)
+static int sh_pmu_prepare_cpu(unsigned int cpu)
 {
        struct cpu_hw_events *cpuhw = &per_cpu(cpu_hw_events, cpu);
 
        memset(cpuhw, 0, sizeof(struct cpu_hw_events));
-}
-
-static int
-sh_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu)
-{
-       unsigned int cpu = (long)hcpu;
-
-       switch (action & ~CPU_TASKS_FROZEN) {
-       case CPU_UP_PREPARE:
-               sh_pmu_setup(cpu);
-               break;
-
-       default:
-               break;
-       }
-
-       return NOTIFY_OK;
+       return 0;
 }
 
 int register_sh_pmu(struct sh_pmu *_pmu)
@@ -394,6 +378,7 @@ int register_sh_pmu(struct sh_pmu *_pmu)
        WARN_ON(_pmu->num_events > MAX_HWEVENTS);
 
        perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
-       perf_cpu_notifier(sh_pmu_notifier);
+       cpuhp_setup_state(CPUHP_PERF_SUPERH, "PERF_SUPERH", sh_pmu_prepare_cpu,
+                         NULL);
        return 0;
 }
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -11,6 +11,7 @@ enum cpuhp_state {
        CPUHP_PERF_X86_RAPL_PREP,
        CPUHP_PERF_BFIN,
        CPUHP_PERF_POWER,
+       CPUHP_PERF_SUPERH,
        CPUHP_NOTIFY_PREPARE,
        CPUHP_BRINGUP_CPU,
        CPUHP_AP_IDLE_DEAD,