Commit 6e2c89d1 authored by viresh kumar's avatar viresh kumar Committed by Rafael J. Wysocki
Browse files

cpufreq: move call to __find_governor() to cpufreq_init_policy() 



We call __find_governor() during the addition of the first CPU of
each policy from __cpufreq_add_dev() to find the last governor used
for this CPU before it was hot-removed.

After that we call cpufreq_parse_governor() in cpufreq_init_policy(),
either with this governor, or with the default governor. Right after
that policy->governor is set to NULL.

While that code is not functionally problematic, the structure of it
is suboptimal, because some of the code required in cpufreq_init_policy()
is being executed by its caller, __cpufreq_add_dev(). So, it would make
more sense to get all of it together in a single place to make code more
readable.

Accordingly, move the code needed for policy initialization to
cpufreq_init_policy() and initialize policy->governor to NULL at the
beginning.

In order to clean up the code a bit more, some of the #ifdefs for
CONFIG_HOTPLUG_CPU are dropped too.

Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
[rjw: Changelog]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 3b4aff04

drivers/cpufreq/cpufreq.c

+14 −24
Original line number Diff line number Diff line
@@ -42,10 +42,8 @@ static DEFINE_RWLOCK(cpufreq_driver_lock); 
DEFINE_MUTEX(cpufreq_governor_lock);

static LIST_HEAD(cpufreq_policy_list);



#ifdef CONFIG_HOTPLUG_CPU

/* This one keeps track of the previously set governor of a removed CPU */

static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor);

#endif



static inline bool has_target(void)

{
@@ -879,18 +877,25 @@ err_out_kobj_put: 


static void cpufreq_init_policy(struct cpufreq_policy *policy)

{

	struct cpufreq_governor *gov = NULL;

	struct cpufreq_policy new_policy;

	int ret = 0;



	memcpy(&new_policy, policy, sizeof(*policy));



	/* Update governor of new_policy to the governor used before hotplug */

	gov = __find_governor(per_cpu(cpufreq_cpu_governor, policy->cpu));

	if (gov)

		pr_debug("Restoring governor %s for cpu %d\n",

				policy->governor->name, policy->cpu);

	else

		gov = CPUFREQ_DEFAULT_GOVERNOR;



	new_policy.governor = gov;



	/* Use the default policy if its valid. */

	if (cpufreq_driver->setpolicy)

		cpufreq_parse_governor(policy->governor->name,

					&new_policy.policy, NULL);



	/* assure that the starting sequence is run in cpufreq_set_policy */

	policy->governor = NULL;

		cpufreq_parse_governor(gov->name, &new_policy.policy, NULL);



	/* set default policy */

	ret = cpufreq_set_policy(policy, &new_policy);
@@ -949,6 +954,8 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) 


	read_unlock_irqrestore(&cpufreq_driver_lock, flags);



	policy->governor = NULL;



	return policy;

}
@@ -1036,7 +1043,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, 
	unsigned long flags;

#ifdef CONFIG_HOTPLUG_CPU

	struct cpufreq_policy *tpolicy;

	struct cpufreq_governor *gov;

#endif



	if (cpu_is_offline(cpu))
@@ -1094,7 +1100,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, 
	else

		policy->cpu = cpu;



	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;

	cpumask_copy(policy->cpus, cpumask_of(cpu));



	init_completion(&policy->kobj_unregister);
@@ -1180,15 +1185,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, 
	blocking_notifier_call_chain(&cpufreq_policy_notifier_list,

				     CPUFREQ_START, policy);



#ifdef CONFIG_HOTPLUG_CPU

	gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu));

	if (gov) {

		policy->governor = gov;

		pr_debug("Restoring governor %s for cpu %d\n",

		       policy->governor->name, cpu);

	}

#endif



	if (!frozen) {

		ret = cpufreq_add_dev_interface(policy, dev);

		if (ret)
@@ -1314,11 +1310,9 @@ static int __cpufreq_remove_dev_prepare(struct device *dev, 
		}

	}



#ifdef CONFIG_HOTPLUG_CPU

	if (!cpufreq_driver->setpolicy)

		strncpy(per_cpu(cpufreq_cpu_governor, cpu),

			policy->governor->name, CPUFREQ_NAME_LEN);

#endif



	down_read(&policy->rwsem);

	cpus = cpumask_weight(policy->cpus);
@@ -1950,9 +1944,7 @@ EXPORT_SYMBOL_GPL(cpufreq_register_governor); 


void cpufreq_unregister_governor(struct cpufreq_governor *governor)

{

#ifdef CONFIG_HOTPLUG_CPU

	int cpu;

#endif



	if (!governor)

		return;
@@ -1960,14 +1952,12 @@ void cpufreq_unregister_governor(struct cpufreq_governor *governor) 
	if (cpufreq_disabled())

		return;



#ifdef CONFIG_HOTPLUG_CPU

	for_each_present_cpu(cpu) {

		if (cpu_online(cpu))

			continue;

		if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name))

			strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0");

	}

#endif



	mutex_lock(&cpufreq_governor_mutex);

	list_del(&governor->governor_list);

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