[linux.git] / drivers / cpufreq / cpufreq_governor_attr_set.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Abstract code for CPUFreq governor tunable sysfs attributes.
 *
 * Copyright (C) 2016, Intel Corporation
 * Author: Rafael J. Wysocki <[email protected]>
 */

#include "cpufreq_governor.h"

static inline struct governor_attr *to_gov_attr(struct attribute *attr)
{
	return container_of(attr, struct governor_attr, attr);
}

static ssize_t governor_show(struct kobject *kobj, struct attribute *attr,
			     char *buf)
{
	struct governor_attr *gattr = to_gov_attr(attr);

	return gattr->show(to_gov_attr_set(kobj), buf);
}

static ssize_t governor_store(struct kobject *kobj, struct attribute *attr,
			      const char *buf, size_t count)
{
	struct gov_attr_set *attr_set = to_gov_attr_set(kobj);
	struct governor_attr *gattr = to_gov_attr(attr);
	int ret;

	mutex_lock(&attr_set->update_lock);
	ret = attr_set->usage_count ? gattr->store(attr_set, buf, count) : -EBUSY;
	mutex_unlock(&attr_set->update_lock);
	return ret;
}

const struct sysfs_ops governor_sysfs_ops = {
	.show	= governor_show,
	.store	= governor_store,
};
EXPORT_SYMBOL_GPL(governor_sysfs_ops);

void gov_attr_set_init(struct gov_attr_set *attr_set, struct list_head *list_node)
{
	INIT_LIST_HEAD(&attr_set->policy_list);
	mutex_init(&attr_set->update_lock);
	attr_set->usage_count = 1;
	list_add(list_node, &attr_set->policy_list);
}
EXPORT_SYMBOL_GPL(gov_attr_set_init);

void gov_attr_set_get(struct gov_attr_set *attr_set, struct list_head *list_node)
{
	mutex_lock(&attr_set->update_lock);
	attr_set->usage_count++;
	list_add(list_node, &attr_set->policy_list);
	mutex_unlock(&attr_set->update_lock);
}
EXPORT_SYMBOL_GPL(gov_attr_set_get);

unsigned int gov_attr_set_put(struct gov_attr_set *attr_set, struct list_head *list_node)
{
	unsigned int count;

	mutex_lock(&attr_set->update_lock);
	list_del(list_node);
	count = --attr_set->usage_count;
	mutex_unlock(&attr_set->update_lock);
	if (count)
		return count;

	mutex_destroy(&attr_set->update_lock);
	kobject_put(&attr_set->kobj);
	return 0;
}
EXPORT_SYMBOL_GPL(gov_attr_set_put);
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
2d0c58ad RW	2	/*
	3	* Abstract code for CPUFreq governor tunable sysfs attributes.
	4	*
	5	* Copyright (C) 2016, Intel Corporation
	6	* Author: Rafael J. Wysocki <[email protected]>
2d0c58ad RW	7	*/
	8
	9	#include "cpufreq_governor.h"
	10
2d0c58ad RW	11	static inline struct governor_attr to_gov_attr(struct attribute attr)
	12	{
	13	return container_of(attr, struct governor_attr, attr);
	14	}
	15
	16	static ssize_t governor_show(struct kobject kobj, struct attribute attr,
	17	char *buf)
	18	{
	19	struct governor_attr *gattr = to_gov_attr(attr);
	20
	21	return gattr->show(to_gov_attr_set(kobj), buf);
	22	}
	23
	24	static ssize_t governor_store(struct kobject kobj, struct attribute attr,
	25	const char *buf, size_t count)
	26	{
	27	struct gov_attr_set *attr_set = to_gov_attr_set(kobj);
	28	struct governor_attr *gattr = to_gov_attr(attr);
	29	int ret;
	30
	31	mutex_lock(&attr_set->update_lock);
	32	ret = attr_set->usage_count ? gattr->store(attr_set, buf, count) : -EBUSY;
	33	mutex_unlock(&attr_set->update_lock);
	34	return ret;
	35	}
	36
	37	const struct sysfs_ops governor_sysfs_ops = {
	38	.show = governor_show,
	39	.store = governor_store,
	40	};
	41	EXPORT_SYMBOL_GPL(governor_sysfs_ops);
	42
	43	void gov_attr_set_init(struct gov_attr_set attr_set, struct list_head list_node)
	44	{
	45	INIT_LIST_HEAD(&attr_set->policy_list);
	46	mutex_init(&attr_set->update_lock);
	47	attr_set->usage_count = 1;
	48	list_add(list_node, &attr_set->policy_list);
	49	}
	50	EXPORT_SYMBOL_GPL(gov_attr_set_init);
	51
	52	void gov_attr_set_get(struct gov_attr_set attr_set, struct list_head list_node)
	53	{
	54	mutex_lock(&attr_set->update_lock);
	55	attr_set->usage_count++;
	56	list_add(list_node, &attr_set->policy_list);
	57	mutex_unlock(&attr_set->update_lock);
	58	}
	59	EXPORT_SYMBOL_GPL(gov_attr_set_get);
	60
	61	unsigned int gov_attr_set_put(struct gov_attr_set attr_set, struct list_head list_node)
	62	{
	63	unsigned int count;
	64
	65	mutex_lock(&attr_set->update_lock);
	66	list_del(list_node);
	67	count = --attr_set->usage_count;
	68	mutex_unlock(&attr_set->update_lock);
	69	if (count)
	70	return count;
	71
2d0c58ad	72	mutex_destroy(&attr_set->update_lock);
cdef1196	73	kobject_put(&attr_set->kobj);
2d0c58ad RW	74	return 0;
	75	}
	76	EXPORT_SYMBOL_GPL(gov_attr_set_put);