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

From: Anna-Maria Gleixner
Date: Mon Jul 11 2016 - 08:45:18 EST


From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

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

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-sh@xxxxxxxxxxxxxxx
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Anna-Maria Gleixner <anna-maria@xxxxxxxxxxxxx>

---
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,