[tip:smp/hotplug] cpufreq: Convert to hotplug state machine

tip-bot for Sebastian Andrzej Siewior
2016-09-19T19:57:29Z

Commit-ID: 27622b061eb4bb4d16b5d61219ac10a792010321
Gitweb: http://git.kernel.org/tip/27622b061eb4bb4d16b5d61219ac10a792010321
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
AuthorDate: Tue, 6 Sep 2016 19:04:48 +0200
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Mon, 19 Sep 2016 21:44:29 +0200

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>

---
drivers/cpufreq/cpufreq.c | 38 ++++++++++++--------------------------
1 file changed, 12 insertions(+), 26 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 3dd4884..e0bc632 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);