cpufreq: Convert to hotplug state machine

Install the callbacks via the state machine.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Viresh Kumar <viresh.kumar@linaro.or
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160906170457.32393-13-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 12 insertions, 26 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 3dd4884c6f9e..e0bc632a259e 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1358,7 +1358,7 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
         return add_cpu_dev_symlink(policy, cpu);
 }
 
-static void cpufreq_offline(unsigned int cpu)
+static int cpufreq_offline(unsigned int cpu)
 {
         struct cpufreq_policy *policy;
         int ret;
@@ -1368,7 +1368,7 @@ static void cpufreq_offline(unsigned int cpu)
         policy = cpufreq_cpu_get_raw(cpu);
         if (!policy) {
                 pr_debug("%s: No cpu_data found\n", __func__);
-                return;
+                return 0;
         }
 
         down_write(&policy->rwsem);
@@ -1417,6 +1417,7 @@ static void cpufreq_offline(unsigned int cpu)
 
 unlock:
         up_write(&policy->rwsem);
+        return 0;
 }
 
 /**
@@ -2332,28 +2333,6 @@ unlock:
 }
 EXPORT_SYMBOL(cpufreq_update_policy);
 
-static int cpufreq_cpu_callback(struct notifier_block *nfb,
-                                        unsigned long action, void *hcpu)
-{
-        unsigned int cpu = (unsigned long)hcpu;
-
-        switch (action & ~CPU_TASKS_FROZEN) {
-        case CPU_ONLINE:
-        case CPU_DOWN_FAILED:
-                cpufreq_online(cpu);
-                break;
-
-        case CPU_DOWN_PREPARE:
-                cpufreq_offline(cpu);
-                break;
-        }
-        return NOTIFY_OK;
-}
-
-static struct notifier_block __refdata cpufreq_cpu_notifier = {
-        .notifier_call = cpufreq_cpu_callback,
-};
-
 /*********************************************************************
  *               BOOST                                               *
  *********************************************************************/
@@ -2455,6 +2434,7 @@ EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
 /*********************************************************************
  *               REGISTER / UNREGISTER CPUFREQ DRIVER                *
  *********************************************************************/
+static enum cpuhp_state hp_online;
 
 /**
  * cpufreq_register_driver - register a CPU Frequency driver
@@ -2517,7 +2497,13 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data)
                 goto err_if_unreg;
         }
 
-        register_hotcpu_notifier(&cpufreq_cpu_notifier);
+        ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "cpufreq:online",
+                                        cpufreq_online,
+                                        cpufreq_offline);
+        if (ret < 0)
+                goto err_if_unreg;
+        hp_online = ret;
+
         pr_debug("driver %s up and running\n", driver_data->name);
         goto out;
 
@@ -2556,7 +2542,7 @@ int cpufreq_unregister_driver(struct cpufreq_driver *driver)
         get_online_cpus();
         subsys_interface_unregister(&cpufreq_interface);
         remove_boost_sysfs_file();
-        unregister_hotcpu_notifier(&cpufreq_cpu_notifier);
+        cpuhp_remove_state_nocalls(hp_online);
 
         write_lock_irqsave(&cpufreq_driver_lock, flags);