77 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			77 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-only
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| /*
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|  * Abstract code for CPUFreq governor tunable sysfs attributes.
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|  *
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|  * Copyright (C) 2016, Intel Corporation
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|  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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|  */
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| 
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| #include "cpufreq_governor.h"
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| 
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| static inline struct governor_attr *to_gov_attr(struct attribute *attr)
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| {
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| 	return container_of(attr, struct governor_attr, attr);
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| }
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| 
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| static ssize_t governor_show(struct kobject *kobj, struct attribute *attr,
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| 			     char *buf)
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| {
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| 	struct governor_attr *gattr = to_gov_attr(attr);
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| 
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| 	return gattr->show(to_gov_attr_set(kobj), buf);
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| }
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| 
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| static ssize_t governor_store(struct kobject *kobj, struct attribute *attr,
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| 			      const char *buf, size_t count)
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| {
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| 	struct gov_attr_set *attr_set = to_gov_attr_set(kobj);
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| 	struct governor_attr *gattr = to_gov_attr(attr);
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| 	int ret;
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| 
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| 	mutex_lock(&attr_set->update_lock);
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| 	ret = attr_set->usage_count ? gattr->store(attr_set, buf, count) : -EBUSY;
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| 	mutex_unlock(&attr_set->update_lock);
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| 	return ret;
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| }
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| 
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| const struct sysfs_ops governor_sysfs_ops = {
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| 	.show	= governor_show,
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| 	.store	= governor_store,
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| };
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| EXPORT_SYMBOL_GPL(governor_sysfs_ops);
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| 
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| void gov_attr_set_init(struct gov_attr_set *attr_set, struct list_head *list_node)
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| {
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| 	INIT_LIST_HEAD(&attr_set->policy_list);
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| 	mutex_init(&attr_set->update_lock);
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| 	attr_set->usage_count = 1;
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| 	list_add(list_node, &attr_set->policy_list);
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| }
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| EXPORT_SYMBOL_GPL(gov_attr_set_init);
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| 
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| void gov_attr_set_get(struct gov_attr_set *attr_set, struct list_head *list_node)
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| {
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| 	mutex_lock(&attr_set->update_lock);
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| 	attr_set->usage_count++;
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| 	list_add(list_node, &attr_set->policy_list);
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| 	mutex_unlock(&attr_set->update_lock);
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| }
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| EXPORT_SYMBOL_GPL(gov_attr_set_get);
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| 
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| unsigned int gov_attr_set_put(struct gov_attr_set *attr_set, struct list_head *list_node)
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| {
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| 	unsigned int count;
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| 
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| 	mutex_lock(&attr_set->update_lock);
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| 	list_del(list_node);
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| 	count = --attr_set->usage_count;
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| 	mutex_unlock(&attr_set->update_lock);
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| 	if (count)
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| 		return count;
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| 
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| 	mutex_destroy(&attr_set->update_lock);
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| 	kobject_put(&attr_set->kobj);
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| 	return 0;
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| }
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| EXPORT_SYMBOL_GPL(gov_attr_set_put);
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