perf/x86/amd/power: Convert the hotplug notifier to state machine

Install the callbacks via the state machine.

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153335.027571056@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/events/amd/power.c b/arch/x86/events/amd/power.c
index 204df18..9842270 100644 (file)
--- a/arch/x86/events/amd/power.c
+++ b/arch/x86/events/amd/power.c
@@ -228,12 +228,12 @@ static struct pmu pmu_class = {
        .read           = pmu_event_read,
 };
 
-static void power_cpu_exit(int cpu)
+static int power_cpu_exit(unsigned int cpu)
 {
        int target;
 
        if (!cpumask_test_and_clear_cpu(cpu, &cpu_mask))
-               return;
+               return 0;
 
        /*
         * Find a new CPU on the same compute unit, if was set in cpumask
@@ -245,9 +245,10 @@ static void power_cpu_exit(int cpu)
                cpumask_set_cpu(target, &cpu_mask);
                perf_pmu_migrate_context(&pmu_class, cpu, target);
        }
+       return 0;
 }
 
-static void power_cpu_init(int cpu)
+static int power_cpu_init(unsigned int cpu)
 {
        int target;
 
@@ -263,33 +264,9 @@ static void power_cpu_init(int cpu)
        target = cpumask_any_but(topology_sibling_cpumask(cpu), cpu);
        if (target >= nr_cpumask_bits)
                cpumask_set_cpu(cpu, &cpu_mask);
+       return 0;
 }
 
-static int
-power_cpu_notifier(struct notifier_block *self, unsigned long action, void *hcpu)
-{
-       unsigned int cpu = (long)hcpu;
-
-       switch (action & ~CPU_TASKS_FROZEN) {
-       case CPU_DOWN_FAILED:
-       case CPU_ONLINE:
-               power_cpu_init(cpu);
-               break;
-       case CPU_DOWN_PREPARE:
-               power_cpu_exit(cpu);
-               break;
-       default:
-               break;
-       }
-
-       return NOTIFY_OK;
-}
-
-static struct notifier_block power_cpu_notifier_nb = {
-       .notifier_call = power_cpu_notifier,
-       .priority = CPU_PRI_PERF,
-};
-
 static const struct x86_cpu_id cpu_match[] = {
        { .vendor = X86_VENDOR_AMD, .family = 0x15 },
        {},
@@ -297,7 +274,7 @@ static const struct x86_cpu_id cpu_match[] = {
 
 static int __init amd_power_pmu_init(void)
 {
-       int cpu, target, ret;
+       int ret;
 
        if (!x86_match_cpu(cpu_match))
                return 0;
@@ -312,38 +289,25 @@ static int __init amd_power_pmu_init(void)
                return -ENODEV;
        }
 
-       cpu_notifier_register_begin();
 
-       /* Choose one online core of each compute unit. */
-       for_each_online_cpu(cpu) {
-               target = cpumask_first(topology_sibling_cpumask(cpu));
-               if (!cpumask_test_cpu(target, &cpu_mask))
-                       cpumask_set_cpu(target, &cpu_mask);
-       }
+       cpuhp_setup_state(CPUHP_AP_PERF_X86_AMD_POWER_ONLINE,
+                         "AP_PERF_X86_AMD_POWER_ONLINE",
+                         power_cpu_init, power_cpu_exit);
 
        ret = perf_pmu_register(&pmu_class, "power", -1);
        if (WARN_ON(ret)) {
                pr_warn("AMD Power PMU registration failed\n");
-               goto out;
+               return ret;
        }
 
-       __register_cpu_notifier(&power_cpu_notifier_nb);
-
        pr_info("AMD Power PMU detected\n");
-
-out:
-       cpu_notifier_register_done();
-
        return ret;
 }
 module_init(amd_power_pmu_init);
 
 static void __exit amd_power_pmu_exit(void)
 {
-       cpu_notifier_register_begin();
-       __unregister_cpu_notifier(&power_cpu_notifier_nb);
-       cpu_notifier_register_done();
-
+       cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_AMD_POWER_ONLINE);
        perf_pmu_unregister(&pmu_class);
 }
 module_exit(amd_power_pmu_exit);

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index f187c46..acfeda1 100644 (file)
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -41,6 +41,7 @@ enum cpuhp_state {
        CPUHP_AP_PERF_X86_ONLINE,
        CPUHP_AP_PERF_X86_UNCORE_ONLINE,
        CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE,
+       CPUHP_AP_PERF_X86_AMD_POWER_ONLINE,
        CPUHP_AP_PERF_X86_RAPL_ONLINE,
        CPUHP_AP_PERF_X86_CQM_ONLINE,
        CPUHP_AP_PERF_X86_CSTATE_ONLINE,