Commit | Line | Data |
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2d0c58ad RW |
1 | /* |
2 | * Abstract code for CPUFreq governor tunable sysfs attributes. | |
3 | * | |
4 | * Copyright (C) 2016, Intel Corporation | |
5 | * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | ||
12 | #include "cpufreq_governor.h" | |
13 | ||
14 | static inline struct gov_attr_set *to_gov_attr_set(struct kobject *kobj) | |
15 | { | |
16 | return container_of(kobj, struct gov_attr_set, kobj); | |
17 | } | |
18 | ||
19 | static inline struct governor_attr *to_gov_attr(struct attribute *attr) | |
20 | { | |
21 | return container_of(attr, struct governor_attr, attr); | |
22 | } | |
23 | ||
24 | static ssize_t governor_show(struct kobject *kobj, struct attribute *attr, | |
25 | char *buf) | |
26 | { | |
27 | struct governor_attr *gattr = to_gov_attr(attr); | |
28 | ||
29 | return gattr->show(to_gov_attr_set(kobj), buf); | |
30 | } | |
31 | ||
32 | static ssize_t governor_store(struct kobject *kobj, struct attribute *attr, | |
33 | const char *buf, size_t count) | |
34 | { | |
35 | struct gov_attr_set *attr_set = to_gov_attr_set(kobj); | |
36 | struct governor_attr *gattr = to_gov_attr(attr); | |
37 | int ret; | |
38 | ||
39 | mutex_lock(&attr_set->update_lock); | |
40 | ret = attr_set->usage_count ? gattr->store(attr_set, buf, count) : -EBUSY; | |
41 | mutex_unlock(&attr_set->update_lock); | |
42 | return ret; | |
43 | } | |
44 | ||
45 | const struct sysfs_ops governor_sysfs_ops = { | |
46 | .show = governor_show, | |
47 | .store = governor_store, | |
48 | }; | |
49 | EXPORT_SYMBOL_GPL(governor_sysfs_ops); | |
50 | ||
51 | void gov_attr_set_init(struct gov_attr_set *attr_set, struct list_head *list_node) | |
52 | { | |
53 | INIT_LIST_HEAD(&attr_set->policy_list); | |
54 | mutex_init(&attr_set->update_lock); | |
55 | attr_set->usage_count = 1; | |
56 | list_add(list_node, &attr_set->policy_list); | |
57 | } | |
58 | EXPORT_SYMBOL_GPL(gov_attr_set_init); | |
59 | ||
60 | void gov_attr_set_get(struct gov_attr_set *attr_set, struct list_head *list_node) | |
61 | { | |
62 | mutex_lock(&attr_set->update_lock); | |
63 | attr_set->usage_count++; | |
64 | list_add(list_node, &attr_set->policy_list); | |
65 | mutex_unlock(&attr_set->update_lock); | |
66 | } | |
67 | EXPORT_SYMBOL_GPL(gov_attr_set_get); | |
68 | ||
69 | unsigned int gov_attr_set_put(struct gov_attr_set *attr_set, struct list_head *list_node) | |
70 | { | |
71 | unsigned int count; | |
72 | ||
73 | mutex_lock(&attr_set->update_lock); | |
74 | list_del(list_node); | |
75 | count = --attr_set->usage_count; | |
76 | mutex_unlock(&attr_set->update_lock); | |
77 | if (count) | |
78 | return count; | |
79 | ||
80 | kobject_put(&attr_set->kobj); | |
81 | mutex_destroy(&attr_set->update_lock); | |
82 | return 0; | |
83 | } | |
84 | EXPORT_SYMBOL_GPL(gov_attr_set_put); |