cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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cpufreq_governor_attr_set.c (2066B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Abstract code for CPUFreq governor tunable sysfs attributes.
      4 *
      5 * Copyright (C) 2016, Intel Corporation
      6 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
      7 */
      8
      9#include "cpufreq_governor.h"
     10
     11static inline struct governor_attr *to_gov_attr(struct attribute *attr)
     12{
     13	return container_of(attr, struct governor_attr, attr);
     14}
     15
     16static 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
     24static 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
     37const struct sysfs_ops governor_sysfs_ops = {
     38	.show	= governor_show,
     39	.store	= governor_store,
     40};
     41EXPORT_SYMBOL_GPL(governor_sysfs_ops);
     42
     43void 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}
     50EXPORT_SYMBOL_GPL(gov_attr_set_init);
     51
     52void 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}
     59EXPORT_SYMBOL_GPL(gov_attr_set_get);
     60
     61unsigned 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
     72	mutex_destroy(&attr_set->update_lock);
     73	kobject_put(&attr_set->kobj);
     74	return 0;
     75}
     76EXPORT_SYMBOL_GPL(gov_attr_set_put);