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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
b86ff982 RW |
2 | /* |
3 | * kernel/power/wakelock.c | |
4 | * | |
5 | * User space wakeup sources support. | |
6 | * | |
7 | * Copyright (C) 2012 Rafael J. Wysocki <rjw@sisk.pl> | |
8 | * | |
9 | * This code is based on the analogous interface allowing user space to | |
10 | * manipulate wakelocks on Android. | |
11 | */ | |
12 | ||
11388c87 | 13 | #include <linux/capability.h> |
b86ff982 RW |
14 | #include <linux/ctype.h> |
15 | #include <linux/device.h> | |
16 | #include <linux/err.h> | |
17 | #include <linux/hrtimer.h> | |
18 | #include <linux/list.h> | |
19 | #include <linux/rbtree.h> | |
20 | #include <linux/slab.h> | |
6ce12a97 | 21 | #include <linux/workqueue.h> |
b86ff982 | 22 | |
6c5be291 RK |
23 | #include "power.h" |
24 | ||
b86ff982 RW |
25 | static DEFINE_MUTEX(wakelocks_lock); |
26 | ||
27 | struct wakelock { | |
28 | char *name; | |
29 | struct rb_node node; | |
2434aea5 | 30 | struct wakeup_source *ws; |
4e585d25 | 31 | #ifdef CONFIG_PM_WAKELOCKS_GC |
b86ff982 | 32 | struct list_head lru; |
4e585d25 | 33 | #endif |
b86ff982 RW |
34 | }; |
35 | ||
36 | static struct rb_root wakelocks_tree = RB_ROOT; | |
b86ff982 RW |
37 | |
38 | ssize_t pm_show_wakelocks(char *buf, bool show_active) | |
39 | { | |
40 | struct rb_node *node; | |
41 | struct wakelock *wl; | |
c9d967b2 | 42 | int len = 0; |
b86ff982 RW |
43 | |
44 | mutex_lock(&wakelocks_lock); | |
45 | ||
46 | for (node = rb_first(&wakelocks_tree); node; node = rb_next(node)) { | |
47 | wl = rb_entry(node, struct wakelock, node); | |
2434aea5 | 48 | if (wl->ws->active == show_active) |
c9d967b2 | 49 | len += sysfs_emit_at(buf, len, "%s ", wl->name); |
b86ff982 | 50 | } |
b86ff982 | 51 | |
c9d967b2 | 52 | len += sysfs_emit_at(buf, len, "\n"); |
b86ff982 RW |
53 | |
54 | mutex_unlock(&wakelocks_lock); | |
c9d967b2 | 55 | return len; |
b86ff982 RW |
56 | } |
57 | ||
c73893e2 RW |
58 | #if CONFIG_PM_WAKELOCKS_LIMIT > 0 |
59 | static unsigned int number_of_wakelocks; | |
60 | ||
61 | static inline bool wakelocks_limit_exceeded(void) | |
62 | { | |
63 | return number_of_wakelocks > CONFIG_PM_WAKELOCKS_LIMIT; | |
64 | } | |
65 | ||
66 | static inline void increment_wakelocks_number(void) | |
67 | { | |
68 | number_of_wakelocks++; | |
69 | } | |
70 | ||
71 | static inline void decrement_wakelocks_number(void) | |
72 | { | |
73 | number_of_wakelocks--; | |
74 | } | |
75 | #else /* CONFIG_PM_WAKELOCKS_LIMIT = 0 */ | |
76 | static inline bool wakelocks_limit_exceeded(void) { return false; } | |
77 | static inline void increment_wakelocks_number(void) {} | |
78 | static inline void decrement_wakelocks_number(void) {} | |
79 | #endif /* CONFIG_PM_WAKELOCKS_LIMIT */ | |
80 | ||
4e585d25 RW |
81 | #ifdef CONFIG_PM_WAKELOCKS_GC |
82 | #define WL_GC_COUNT_MAX 100 | |
83 | #define WL_GC_TIME_SEC 300 | |
84 | ||
6ce12a97 | 85 | static void __wakelocks_gc(struct work_struct *work); |
4e585d25 | 86 | static LIST_HEAD(wakelocks_lru_list); |
6ce12a97 | 87 | static DECLARE_WORK(wakelock_work, __wakelocks_gc); |
4e585d25 RW |
88 | static unsigned int wakelocks_gc_count; |
89 | ||
90 | static inline void wakelocks_lru_add(struct wakelock *wl) | |
91 | { | |
92 | list_add(&wl->lru, &wakelocks_lru_list); | |
93 | } | |
94 | ||
95 | static inline void wakelocks_lru_most_recent(struct wakelock *wl) | |
96 | { | |
97 | list_move(&wl->lru, &wakelocks_lru_list); | |
98 | } | |
99 | ||
6ce12a97 | 100 | static void __wakelocks_gc(struct work_struct *work) |
4e585d25 RW |
101 | { |
102 | struct wakelock *wl, *aux; | |
103 | ktime_t now; | |
104 | ||
6ce12a97 | 105 | mutex_lock(&wakelocks_lock); |
4e585d25 RW |
106 | |
107 | now = ktime_get(); | |
108 | list_for_each_entry_safe_reverse(wl, aux, &wakelocks_lru_list, lru) { | |
109 | u64 idle_time_ns; | |
110 | bool active; | |
111 | ||
2434aea5 TV |
112 | spin_lock_irq(&wl->ws->lock); |
113 | idle_time_ns = ktime_to_ns(ktime_sub(now, wl->ws->last_time)); | |
114 | active = wl->ws->active; | |
115 | spin_unlock_irq(&wl->ws->lock); | |
4e585d25 RW |
116 | |
117 | if (idle_time_ns < ((u64)WL_GC_TIME_SEC * NSEC_PER_SEC)) | |
118 | break; | |
119 | ||
120 | if (!active) { | |
2434aea5 | 121 | wakeup_source_unregister(wl->ws); |
4e585d25 RW |
122 | rb_erase(&wl->node, &wakelocks_tree); |
123 | list_del(&wl->lru); | |
124 | kfree(wl->name); | |
125 | kfree(wl); | |
126 | decrement_wakelocks_number(); | |
127 | } | |
128 | } | |
129 | wakelocks_gc_count = 0; | |
6ce12a97 SK |
130 | |
131 | mutex_unlock(&wakelocks_lock); | |
132 | } | |
133 | ||
134 | static void wakelocks_gc(void) | |
135 | { | |
136 | if (++wakelocks_gc_count <= WL_GC_COUNT_MAX) | |
137 | return; | |
138 | ||
139 | schedule_work(&wakelock_work); | |
4e585d25 RW |
140 | } |
141 | #else /* !CONFIG_PM_WAKELOCKS_GC */ | |
142 | static inline void wakelocks_lru_add(struct wakelock *wl) {} | |
143 | static inline void wakelocks_lru_most_recent(struct wakelock *wl) {} | |
144 | static inline void wakelocks_gc(void) {} | |
145 | #endif /* !CONFIG_PM_WAKELOCKS_GC */ | |
146 | ||
b86ff982 RW |
147 | static struct wakelock *wakelock_lookup_add(const char *name, size_t len, |
148 | bool add_if_not_found) | |
149 | { | |
150 | struct rb_node **node = &wakelocks_tree.rb_node; | |
151 | struct rb_node *parent = *node; | |
152 | struct wakelock *wl; | |
153 | ||
154 | while (*node) { | |
155 | int diff; | |
156 | ||
157 | parent = *node; | |
158 | wl = rb_entry(*node, struct wakelock, node); | |
159 | diff = strncmp(name, wl->name, len); | |
160 | if (diff == 0) { | |
161 | if (wl->name[len]) | |
162 | diff = -1; | |
163 | else | |
164 | return wl; | |
165 | } | |
166 | if (diff < 0) | |
167 | node = &(*node)->rb_left; | |
168 | else | |
169 | node = &(*node)->rb_right; | |
170 | } | |
171 | if (!add_if_not_found) | |
172 | return ERR_PTR(-EINVAL); | |
173 | ||
c73893e2 | 174 | if (wakelocks_limit_exceeded()) |
b86ff982 RW |
175 | return ERR_PTR(-ENOSPC); |
176 | ||
177 | /* Not found, we have to add a new one. */ | |
178 | wl = kzalloc(sizeof(*wl), GFP_KERNEL); | |
179 | if (!wl) | |
180 | return ERR_PTR(-ENOMEM); | |
181 | ||
182 | wl->name = kstrndup(name, len, GFP_KERNEL); | |
183 | if (!wl->name) { | |
184 | kfree(wl); | |
185 | return ERR_PTR(-ENOMEM); | |
186 | } | |
2434aea5 | 187 | |
c8377adf | 188 | wl->ws = wakeup_source_register(NULL, wl->name); |
2434aea5 TV |
189 | if (!wl->ws) { |
190 | kfree(wl->name); | |
191 | kfree(wl); | |
192 | return ERR_PTR(-ENOMEM); | |
193 | } | |
194 | wl->ws->last_time = ktime_get(); | |
195 | ||
b86ff982 RW |
196 | rb_link_node(&wl->node, parent, node); |
197 | rb_insert_color(&wl->node, &wakelocks_tree); | |
4e585d25 | 198 | wakelocks_lru_add(wl); |
c73893e2 | 199 | increment_wakelocks_number(); |
b86ff982 RW |
200 | return wl; |
201 | } | |
202 | ||
203 | int pm_wake_lock(const char *buf) | |
204 | { | |
205 | const char *str = buf; | |
206 | struct wakelock *wl; | |
207 | u64 timeout_ns = 0; | |
208 | size_t len; | |
209 | int ret = 0; | |
210 | ||
11388c87 RW |
211 | if (!capable(CAP_BLOCK_SUSPEND)) |
212 | return -EPERM; | |
213 | ||
b86ff982 RW |
214 | while (*str && !isspace(*str)) |
215 | str++; | |
216 | ||
217 | len = str - buf; | |
218 | if (!len) | |
219 | return -EINVAL; | |
220 | ||
221 | if (*str && *str != '\n') { | |
222 | /* Find out if there's a valid timeout string appended. */ | |
223 | ret = kstrtou64(skip_spaces(str), 10, &timeout_ns); | |
224 | if (ret) | |
225 | return -EINVAL; | |
226 | } | |
227 | ||
228 | mutex_lock(&wakelocks_lock); | |
229 | ||
230 | wl = wakelock_lookup_add(buf, len, true); | |
231 | if (IS_ERR(wl)) { | |
232 | ret = PTR_ERR(wl); | |
233 | goto out; | |
234 | } | |
235 | if (timeout_ns) { | |
236 | u64 timeout_ms = timeout_ns + NSEC_PER_MSEC - 1; | |
237 | ||
238 | do_div(timeout_ms, NSEC_PER_MSEC); | |
2434aea5 | 239 | __pm_wakeup_event(wl->ws, timeout_ms); |
b86ff982 | 240 | } else { |
2434aea5 | 241 | __pm_stay_awake(wl->ws); |
b86ff982 RW |
242 | } |
243 | ||
4e585d25 | 244 | wakelocks_lru_most_recent(wl); |
b86ff982 RW |
245 | |
246 | out: | |
247 | mutex_unlock(&wakelocks_lock); | |
248 | return ret; | |
249 | } | |
250 | ||
b86ff982 RW |
251 | int pm_wake_unlock(const char *buf) |
252 | { | |
253 | struct wakelock *wl; | |
254 | size_t len; | |
255 | int ret = 0; | |
256 | ||
11388c87 RW |
257 | if (!capable(CAP_BLOCK_SUSPEND)) |
258 | return -EPERM; | |
259 | ||
b86ff982 RW |
260 | len = strlen(buf); |
261 | if (!len) | |
262 | return -EINVAL; | |
263 | ||
264 | if (buf[len-1] == '\n') | |
265 | len--; | |
266 | ||
267 | if (!len) | |
268 | return -EINVAL; | |
269 | ||
270 | mutex_lock(&wakelocks_lock); | |
271 | ||
272 | wl = wakelock_lookup_add(buf, len, false); | |
273 | if (IS_ERR(wl)) { | |
274 | ret = PTR_ERR(wl); | |
275 | goto out; | |
276 | } | |
2434aea5 | 277 | __pm_relax(wl->ws); |
4e585d25 RW |
278 | |
279 | wakelocks_lru_most_recent(wl); | |
280 | wakelocks_gc(); | |
b86ff982 RW |
281 | |
282 | out: | |
283 | mutex_unlock(&wakelocks_lock); | |
284 | return ret; | |
285 | } |