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