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Commit 988bed09 authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki
Browse files

cpufreq: Don't clear cpufreq_cpu_data and policy list for inactive policies 



Now that we can check policy->cpus to find if policy is active or not,
we don't need to clean cpufreq_cpu_data and delete policy from the list
on light weight tear down of policies (like in suspend).

To make it consistent and clean, set cpufreq_cpu_data for all related
CPUs when the policy is first created and clean it only while it is
freed.

Also update cpufreq_cpu_get_raw() to check if cpu is part of
policy->cpus mask, so that we don't end up getting policies for offline
CPUs.

In order to make sure that no users of 'policy' are using an inactive
policy, use cpufreq_cpu_get_raw() instead of directly accessing
cpufreq_cpu_data.

Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent f963735a

drivers/cpufreq/cpufreq.c

+34 −45
Original line number Diff line number Diff line
@@ -239,10 +239,18 @@ int cpufreq_generic_init(struct cpufreq_policy *policy, 
}

EXPORT_SYMBOL_GPL(cpufreq_generic_init);



unsigned int cpufreq_generic_get(unsigned int cpu)

/* Only for cpufreq core internal use */

struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)

{

	struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);



	return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL;

}



unsigned int cpufreq_generic_get(unsigned int cpu)

{

	struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);



	if (!policy || IS_ERR(policy->clk)) {

		pr_err("%s: No %s associated to cpu: %d\n",

		       __func__, policy ? "clk" : "policy", cpu);
@@ -253,12 +261,6 @@ unsigned int cpufreq_generic_get(unsigned int cpu) 
}

EXPORT_SYMBOL_GPL(cpufreq_generic_get);



/* Only for cpufreq core internal use */

struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)

{

	return per_cpu(cpufreq_cpu_data, cpu);

}



/**

 * cpufreq_cpu_get: returns policy for a cpu and marks it busy.

 *
@@ -292,7 +294,7 @@ struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) 


	if (cpufreq_driver) {

		/* get the CPU */

		policy = per_cpu(cpufreq_cpu_data, cpu);

		policy = cpufreq_cpu_get_raw(cpu);

		if (policy)

			kobject_get(&policy->kobj);

	}
@@ -1042,7 +1044,6 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, 
				  unsigned int cpu, struct device *dev)

{

	int ret = 0;

	unsigned long flags;



	/* Has this CPU been taken care of already? */

	if (cpumask_test_cpu(cpu, policy->cpus))
@@ -1057,13 +1058,7 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, 
	}



	down_write(&policy->rwsem);



	write_lock_irqsave(&cpufreq_driver_lock, flags);



	cpumask_set_cpu(cpu, policy->cpus);

	per_cpu(cpufreq_cpu_data, cpu) = policy;

	write_unlock_irqrestore(&cpufreq_driver_lock, flags);



	up_write(&policy->rwsem);



	if (has_target()) {
@@ -1154,6 +1149,17 @@ static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) 


static void cpufreq_policy_free(struct cpufreq_policy *policy)

{

	unsigned long flags;

	int cpu;



	/* Remove policy from list */

	write_lock_irqsave(&cpufreq_driver_lock, flags);

	list_del(&policy->policy_list);



	for_each_cpu(cpu, policy->related_cpus)

		per_cpu(cpufreq_cpu_data, cpu) = NULL;

	write_unlock_irqrestore(&cpufreq_driver_lock, flags);



	free_cpumask_var(policy->related_cpus);

	free_cpumask_var(policy->cpus);

	kfree(policy);
@@ -1275,12 +1281,12 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) 
			       __func__, ret);

			goto err_init_policy_kobj;

		}

	}



		write_lock_irqsave(&cpufreq_driver_lock, flags);

	for_each_cpu(j, policy->cpus)

		for_each_cpu(j, policy->related_cpus)

			per_cpu(cpufreq_cpu_data, j) = policy;

		write_unlock_irqrestore(&cpufreq_driver_lock, flags);

	}



	if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {

		policy->cur = cpufreq_driver->get(policy->cpu);
@@ -1339,11 +1345,11 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) 
			goto err_out_unregister;

		blocking_notifier_call_chain(&cpufreq_policy_notifier_list,

				CPUFREQ_CREATE_POLICY, policy);

	}



		write_lock_irqsave(&cpufreq_driver_lock, flags);

		list_add(&policy->policy_list, &cpufreq_policy_list);

		write_unlock_irqrestore(&cpufreq_driver_lock, flags);

	}



	cpufreq_init_policy(policy);
@@ -1367,11 +1373,6 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) 


err_out_unregister:

err_get_freq:

	write_lock_irqsave(&cpufreq_driver_lock, flags);

	for_each_cpu(j, policy->cpus)

		per_cpu(cpufreq_cpu_data, j) = NULL;

	write_unlock_irqrestore(&cpufreq_driver_lock, flags);



	if (!recover_policy) {

		kobject_put(&policy->kobj);

		wait_for_completion(&policy->kobj_unregister);
@@ -1407,7 +1408,7 @@ static int __cpufreq_remove_dev_prepare(struct device *dev, 


	write_lock_irqsave(&cpufreq_driver_lock, flags);



	policy = per_cpu(cpufreq_cpu_data, cpu);

	policy = cpufreq_cpu_get_raw(cpu);



	/* Save the policy somewhere when doing a light-weight tear-down */

	if (cpufreq_suspended)
@@ -1465,15 +1466,9 @@ static int __cpufreq_remove_dev_prepare(struct device *dev, 
static int __cpufreq_remove_dev_finish(struct device *dev,

				       struct subsys_interface *sif)

{

	unsigned int cpu = dev->id, cpus;

	unsigned int cpu = dev->id;

	int ret;

	unsigned long flags;

	struct cpufreq_policy *policy;



	write_lock_irqsave(&cpufreq_driver_lock, flags);

	policy = per_cpu(cpufreq_cpu_data, cpu);

	per_cpu(cpufreq_cpu_data, cpu) = NULL;

	write_unlock_irqrestore(&cpufreq_driver_lock, flags);

	struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);



	if (!policy) {

		pr_debug("%s: No cpu_data found\n", __func__);
@@ -1481,12 +1476,11 @@ static int __cpufreq_remove_dev_finish(struct device *dev, 
	}



	down_write(&policy->rwsem);

	cpus = cpumask_weight(policy->cpus);

	cpumask_clear_cpu(cpu, policy->cpus);

	up_write(&policy->rwsem);



	/* If cpu is last user of policy, free policy */

	if (cpus == 1) {

	if (policy_is_inactive(policy)) {

		if (has_target()) {

			ret = __cpufreq_governor(policy,

					CPUFREQ_GOV_POLICY_EXIT);
@@ -1508,11 +1502,6 @@ static int __cpufreq_remove_dev_finish(struct device *dev, 
		if (cpufreq_driver->exit)

			cpufreq_driver->exit(policy);



		/* Remove policy from list of active policies */

		write_lock_irqsave(&cpufreq_driver_lock, flags);

		list_del(&policy->policy_list);

		write_unlock_irqrestore(&cpufreq_driver_lock, flags);



		if (!cpufreq_suspended)

			cpufreq_policy_free(policy);

	} else if (has_target()) {