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Commit 474deff7 authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki
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cpufreq: remove cpufreq_policy_cpu per-cpu variable 



cpufreq_policy_cpu per-cpu variables are used for storing the ID of
the CPU that manages the given CPU's policy.  However, we also store
a policy pointer for each cpu in cpufreq_cpu_data, so the
cpufreq_policy_cpu information is simply redundant.

It is better to use cpufreq_cpu_data to retrieve a policy and get
policy->cpu from there, so make that happen everywhere and drop the
cpufreq_policy_cpu per-cpu variables which aren't necessary any more.

[rjw: Changelog]
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 9e9fd801

drivers/cpufreq/cpufreq.c

+10 −35
Original line number Diff line number Diff line
@@ -64,15 +64,14 @@ static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); 
 * - Lock should not be held across

 *     __cpufreq_governor(data, CPUFREQ_GOV_STOP);

 */

static DEFINE_PER_CPU(int, cpufreq_policy_cpu);

static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem);



#define lock_policy_rwsem(mode, cpu)					\

static int lock_policy_rwsem_##mode(int cpu)				\

{									\

	int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu);		\

	BUG_ON(policy_cpu == -1);					\

	down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu));		\

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

	BUG_ON(!policy);						\

	down_##mode(&per_cpu(cpu_policy_rwsem, policy->cpu));		\

									\

	return 0;							\

}
@@ -83,9 +82,9 @@ lock_policy_rwsem(write, cpu); 
#define unlock_policy_rwsem(mode, cpu)					\

static void unlock_policy_rwsem_##mode(int cpu)				\

{									\

	int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu);		\

	BUG_ON(policy_cpu == -1);					\

	up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu));		\

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

	BUG_ON(!policy);						\

	up_##mode(&per_cpu(cpu_policy_rwsem, policy->cpu));		\

}



unlock_policy_rwsem(read, cpu);
@@ -887,7 +886,6 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, 
	write_lock_irqsave(&cpufreq_driver_lock, flags);



	cpumask_set_cpu(cpu, policy->cpus);

	per_cpu(cpufreq_policy_cpu, cpu) = policy->cpu;

	per_cpu(cpufreq_cpu_data, cpu) = policy;

	write_unlock_irqrestore(&cpufreq_driver_lock, flags);
@@ -1013,9 +1011,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, 
	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;

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



	/* Initially set CPU itself as the policy_cpu */

	per_cpu(cpufreq_policy_cpu, cpu) = cpu;



	init_completion(&policy->kobj_unregister);

	INIT_WORK(&policy->update, handle_update);
@@ -1053,10 +1048,8 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, 
#endif



	write_lock_irqsave(&cpufreq_driver_lock, flags);

	for_each_cpu(j, policy->cpus) {

	for_each_cpu(j, policy->cpus)

		per_cpu(cpufreq_cpu_data, j) = policy;

		per_cpu(cpufreq_policy_cpu, j) = policy->cpu;

	}

	write_unlock_irqrestore(&cpufreq_driver_lock, flags);



	if (!frozen) {
@@ -1080,15 +1073,11 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, 


err_out_unregister:

	write_lock_irqsave(&cpufreq_driver_lock, flags);

	for_each_cpu(j, policy->cpus) {

	for_each_cpu(j, policy->cpus)

		per_cpu(cpufreq_cpu_data, j) = NULL;

		if (j != cpu)

			per_cpu(cpufreq_policy_cpu, j) = -1;

	}

	write_unlock_irqrestore(&cpufreq_driver_lock, flags);



err_set_policy_cpu:

	per_cpu(cpufreq_policy_cpu, cpu) = -1;

	cpufreq_policy_free(policy);

nomem_out:

	up_read(&cpufreq_rwsem);
@@ -1112,14 +1101,9 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) 


static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)

{

	int j;



	policy->last_cpu = policy->cpu;

	policy->cpu = cpu;



	for_each_cpu(j, policy->cpus)

		per_cpu(cpufreq_policy_cpu, j) = cpu;



#ifdef CONFIG_CPU_FREQ_TABLE

	cpufreq_frequency_table_update_policy_cpu(policy);

#endif
@@ -1131,7 +1115,6 @@ static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy, 
					   unsigned int old_cpu, bool frozen)

{

	struct device *cpu_dev;

	unsigned long flags;

	int ret;



	/* first sibling now owns the new sysfs dir */
@@ -1148,11 +1131,6 @@ static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy, 


		WARN_ON(lock_policy_rwsem_write(old_cpu));

		cpumask_set_cpu(old_cpu, policy->cpus);



		write_lock_irqsave(&cpufreq_driver_lock, flags);

		per_cpu(cpufreq_cpu_data, old_cpu) = policy;

		write_unlock_irqrestore(&cpufreq_driver_lock, flags);



		unlock_policy_rwsem_write(old_cpu);



		ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj,
@@ -1186,7 +1164,6 @@ static int __cpufreq_remove_dev(struct device *dev, 
	write_lock_irqsave(&cpufreq_driver_lock, flags);



	policy = per_cpu(cpufreq_cpu_data, cpu);

	per_cpu(cpufreq_cpu_data, cpu) = NULL;



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

	if (frozen)
@@ -1292,7 +1269,7 @@ static int __cpufreq_remove_dev(struct device *dev, 
		}

	}



	per_cpu(cpufreq_policy_cpu, cpu) = -1;

	per_cpu(cpufreq_cpu_data, cpu) = NULL;

	return 0;

}
@@ -2148,10 +2125,8 @@ static int __init cpufreq_core_init(void) 
	if (cpufreq_disabled())

		return -ENODEV;



	for_each_possible_cpu(cpu) {

		per_cpu(cpufreq_policy_cpu, cpu) = -1;

	for_each_possible_cpu(cpu)

		init_rwsem(&per_cpu(cpu_policy_rwsem, cpu));

	}



	cpufreq_global_kobject = kobject_create();

	BUG_ON(!cpufreq_global_kobject);