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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 <rafael.j.wysocki@intel.com> | |
2d0c58ad RW |
7 | */ |
8 | ||
9 | #include "cpufreq_governor.h" | |
10 | ||
11 | static inline struct gov_attr_set *to_gov_attr_set(struct kobject *kobj) | |
12 | { | |
13 | return container_of(kobj, struct gov_attr_set, kobj); | |
14 | } | |
15 | ||
16 | static inline struct governor_attr *to_gov_attr(struct attribute *attr) | |
17 | { | |
18 | return container_of(attr, struct governor_attr, attr); | |
19 | } | |
20 | ||
21 | static ssize_t governor_show(struct kobject *kobj, struct attribute *attr, | |
22 | char *buf) | |
23 | { | |
24 | struct governor_attr *gattr = to_gov_attr(attr); | |
25 | ||
26 | return gattr->show(to_gov_attr_set(kobj), buf); | |
27 | } | |
28 | ||
29 | static ssize_t governor_store(struct kobject *kobj, struct attribute *attr, | |
30 | const char *buf, size_t count) | |
31 | { | |
32 | struct gov_attr_set *attr_set = to_gov_attr_set(kobj); | |
33 | struct governor_attr *gattr = to_gov_attr(attr); | |
34 | int ret; | |
35 | ||
36 | mutex_lock(&attr_set->update_lock); | |
37 | ret = attr_set->usage_count ? gattr->store(attr_set, buf, count) : -EBUSY; | |
38 | mutex_unlock(&attr_set->update_lock); | |
39 | return ret; | |
40 | } | |
41 | ||
42 | const struct sysfs_ops governor_sysfs_ops = { | |
43 | .show = governor_show, | |
44 | .store = governor_store, | |
45 | }; | |
46 | EXPORT_SYMBOL_GPL(governor_sysfs_ops); | |
47 | ||
48 | void gov_attr_set_init(struct gov_attr_set *attr_set, struct list_head *list_node) | |
49 | { | |
50 | INIT_LIST_HEAD(&attr_set->policy_list); | |
51 | mutex_init(&attr_set->update_lock); | |
52 | attr_set->usage_count = 1; | |
53 | list_add(list_node, &attr_set->policy_list); | |
54 | } | |
55 | EXPORT_SYMBOL_GPL(gov_attr_set_init); | |
56 | ||
57 | void gov_attr_set_get(struct gov_attr_set *attr_set, struct list_head *list_node) | |
58 | { | |
59 | mutex_lock(&attr_set->update_lock); | |
60 | attr_set->usage_count++; | |
61 | list_add(list_node, &attr_set->policy_list); | |
62 | mutex_unlock(&attr_set->update_lock); | |
63 | } | |
64 | EXPORT_SYMBOL_GPL(gov_attr_set_get); | |
65 | ||
66 | unsigned int gov_attr_set_put(struct gov_attr_set *attr_set, struct list_head *list_node) | |
67 | { | |
68 | unsigned int count; | |
69 | ||
70 | mutex_lock(&attr_set->update_lock); | |
71 | list_del(list_node); | |
72 | count = --attr_set->usage_count; | |
73 | mutex_unlock(&attr_set->update_lock); | |
74 | if (count) | |
75 | return count; | |
76 | ||
77 | kobject_put(&attr_set->kobj); | |
78 | mutex_destroy(&attr_set->update_lock); | |
79 | return 0; | |
80 | } | |
81 | EXPORT_SYMBOL_GPL(gov_attr_set_put); |