cpuidle/coupled: Convert to hotplug state machine

Install the callbacks via the state machine.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-pm@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160824091444.brdr5zpbxjvh6n3f@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/drivers/cpuidle/coupled.c b/drivers/cpuidle/coupled.c
index d5657d50ac4044d5da886050e822517fe1134b6f..71e586d7df71722364f051ce0148479631c76fdb 100644 (file)
--- a/drivers/cpuidle/coupled.c
+++ b/drivers/cpuidle/coupled.c
@@ -749,65 +749,52 @@ static void cpuidle_coupled_allow_idle(struct cpuidle_coupled *coupled)
        put_cpu();
 }
 
-/**
- * cpuidle_coupled_cpu_notify - notifier called during hotplug transitions
- * @nb: notifier block
- * @action: hotplug transition
- * @hcpu: target cpu number
- *
- * Called when a cpu is brought on or offline using hotplug.  Updates the
- * coupled cpu set appropriately
- */
-static int cpuidle_coupled_cpu_notify(struct notifier_block *nb,
-               unsigned long action, void *hcpu)
+static int coupled_cpu_online(unsigned int cpu)
 {
-       int cpu = (unsigned long)hcpu;
        struct cpuidle_device *dev;
 
-       switch (action & ~CPU_TASKS_FROZEN) {
-       case CPU_UP_PREPARE:
-       case CPU_DOWN_PREPARE:
-       case CPU_ONLINE:
-       case CPU_DEAD:
-       case CPU_UP_CANCELED:
-       case CPU_DOWN_FAILED:
-               break;
-       default:
-               return NOTIFY_OK;
-       }
-
        mutex_lock(&cpuidle_lock);
 
        dev = per_cpu(cpuidle_devices, cpu);
-       if (!dev || !dev->coupled)
-               goto out;
-
-       switch (action & ~CPU_TASKS_FROZEN) {
-       case CPU_UP_PREPARE:
-       case CPU_DOWN_PREPARE:
-               cpuidle_coupled_prevent_idle(dev->coupled);
-               break;
-       case CPU_ONLINE:
-       case CPU_DEAD:
+       if (dev && dev->coupled) {
                cpuidle_coupled_update_online_cpus(dev->coupled);
-               /* Fall through */
-       case CPU_UP_CANCELED:
-       case CPU_DOWN_FAILED:
                cpuidle_coupled_allow_idle(dev->coupled);
-               break;
        }
 
-out:
        mutex_unlock(&cpuidle_lock);
-       return NOTIFY_OK;
+       return 0;
 }
 
-static struct notifier_block cpuidle_coupled_cpu_notifier = {
-       .notifier_call = cpuidle_coupled_cpu_notify,
-};
+static int coupled_cpu_up_prepare(unsigned int cpu)
+{
+       struct cpuidle_device *dev;
+
+       mutex_lock(&cpuidle_lock);
+
+       dev = per_cpu(cpuidle_devices, cpu);
+       if (dev && dev->coupled)
+               cpuidle_coupled_prevent_idle(dev->coupled);
+
+       mutex_unlock(&cpuidle_lock);
+       return 0;
+}
 
 static int __init cpuidle_coupled_init(void)
 {
-       return register_cpu_notifier(&cpuidle_coupled_cpu_notifier);
+       int ret;
+
+       ret = cpuhp_setup_state_nocalls(CPUHP_CPUIDLE_COUPLED_PREPARE,
+                                       "cpuidle/coupled:prepare",
+                                       coupled_cpu_up_prepare,
+                                       coupled_cpu_online);
+       if (ret)
+               return ret;
+       ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
+                                       "cpuidle/coupled:online",
+                                       coupled_cpu_online,
+                                       coupled_cpu_up_prepare);
+       if (ret < 0)
+               cpuhp_remove_state_nocalls(CPUHP_CPUIDLE_COUPLED_PREPARE);
+       return ret;
 }
 core_initcall(cpuidle_coupled_init);

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 0fb22b95649fa7a8d23911f928b436e7a27d1547..e8608774b5da0ed321401b03e8fe975750604c76 100644 (file)
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -30,6 +30,7 @@ enum cpuhp_state {
        CPUHP_SLAB_PREPARE,
        CPUHP_MD_RAID5_PREPARE,
        CPUHP_RCUTREE_PREP,
+       CPUHP_CPUIDLE_COUPLED_PREPARE,
        CPUHP_NOTIFY_PREPARE,
        CPUHP_TIMERS_DEAD,
        CPUHP_BRINGUP_CPU,