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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> | |
20 | ||
b86ff982 RW |
21 | static DEFINE_MUTEX(wakelocks_lock); |
22 | ||
23 | struct wakelock { | |
24 | char *name; | |
25 | struct rb_node node; | |
26 | struct wakeup_source ws; | |
4e585d25 | 27 | #ifdef CONFIG_PM_WAKELOCKS_GC |
b86ff982 | 28 | struct list_head lru; |
4e585d25 | 29 | #endif |
b86ff982 RW |
30 | }; |
31 | ||
32 | static struct rb_root wakelocks_tree = RB_ROOT; | |
b86ff982 RW |
33 | |
34 | ssize_t pm_show_wakelocks(char *buf, bool show_active) | |
35 | { | |
36 | struct rb_node *node; | |
37 | struct wakelock *wl; | |
38 | char *str = buf; | |
39 | char *end = buf + PAGE_SIZE; | |
40 | ||
41 | mutex_lock(&wakelocks_lock); | |
42 | ||
43 | for (node = rb_first(&wakelocks_tree); node; node = rb_next(node)) { | |
44 | wl = rb_entry(node, struct wakelock, node); | |
45 | if (wl->ws.active == show_active) | |
46 | str += scnprintf(str, end - str, "%s ", wl->name); | |
47 | } | |
48 | if (str > buf) | |
49 | str--; | |
50 | ||
51 | str += scnprintf(str, end - str, "\n"); | |
52 | ||
53 | mutex_unlock(&wakelocks_lock); | |
54 | return (str - buf); | |
55 | } | |
56 | ||
c73893e2 RW |
57 | #if CONFIG_PM_WAKELOCKS_LIMIT > 0 |
58 | static unsigned int number_of_wakelocks; | |
59 | ||
60 | static inline bool wakelocks_limit_exceeded(void) | |
61 | { | |
62 | return number_of_wakelocks > CONFIG_PM_WAKELOCKS_LIMIT; | |
63 | } | |
64 | ||
65 | static inline void increment_wakelocks_number(void) | |
66 | { | |
67 | number_of_wakelocks++; | |
68 | } | |
69 | ||
70 | static inline void decrement_wakelocks_number(void) | |
71 | { | |
72 | number_of_wakelocks--; | |
73 | } | |
74 | #else /* CONFIG_PM_WAKELOCKS_LIMIT = 0 */ | |
75 | static inline bool wakelocks_limit_exceeded(void) { return false; } | |
76 | static inline void increment_wakelocks_number(void) {} | |
77 | static inline void decrement_wakelocks_number(void) {} | |
78 | #endif /* CONFIG_PM_WAKELOCKS_LIMIT */ | |
79 | ||
4e585d25 RW |
80 | #ifdef CONFIG_PM_WAKELOCKS_GC |
81 | #define WL_GC_COUNT_MAX 100 | |
82 | #define WL_GC_TIME_SEC 300 | |
83 | ||
84 | static LIST_HEAD(wakelocks_lru_list); | |
85 | static unsigned int wakelocks_gc_count; | |
86 | ||
87 | static inline void wakelocks_lru_add(struct wakelock *wl) | |
88 | { | |
89 | list_add(&wl->lru, &wakelocks_lru_list); | |
90 | } | |
91 | ||
92 | static inline void wakelocks_lru_most_recent(struct wakelock *wl) | |
93 | { | |
94 | list_move(&wl->lru, &wakelocks_lru_list); | |
95 | } | |
96 | ||
97 | static void wakelocks_gc(void) | |
98 | { | |
99 | struct wakelock *wl, *aux; | |
100 | ktime_t now; | |
101 | ||
102 | if (++wakelocks_gc_count <= WL_GC_COUNT_MAX) | |
103 | return; | |
104 | ||
105 | now = ktime_get(); | |
106 | list_for_each_entry_safe_reverse(wl, aux, &wakelocks_lru_list, lru) { | |
107 | u64 idle_time_ns; | |
108 | bool active; | |
109 | ||
110 | spin_lock_irq(&wl->ws.lock); | |
111 | idle_time_ns = ktime_to_ns(ktime_sub(now, wl->ws.last_time)); | |
112 | active = wl->ws.active; | |
113 | spin_unlock_irq(&wl->ws.lock); | |
114 | ||
115 | if (idle_time_ns < ((u64)WL_GC_TIME_SEC * NSEC_PER_SEC)) | |
116 | break; | |
117 | ||
118 | if (!active) { | |
119 | wakeup_source_remove(&wl->ws); | |
120 | rb_erase(&wl->node, &wakelocks_tree); | |
121 | list_del(&wl->lru); | |
122 | kfree(wl->name); | |
123 | kfree(wl); | |
124 | decrement_wakelocks_number(); | |
125 | } | |
126 | } | |
127 | wakelocks_gc_count = 0; | |
128 | } | |
129 | #else /* !CONFIG_PM_WAKELOCKS_GC */ | |
130 | static inline void wakelocks_lru_add(struct wakelock *wl) {} | |
131 | static inline void wakelocks_lru_most_recent(struct wakelock *wl) {} | |
132 | static inline void wakelocks_gc(void) {} | |
133 | #endif /* !CONFIG_PM_WAKELOCKS_GC */ | |
134 | ||
b86ff982 RW |
135 | static struct wakelock *wakelock_lookup_add(const char *name, size_t len, |
136 | bool add_if_not_found) | |
137 | { | |
138 | struct rb_node **node = &wakelocks_tree.rb_node; | |
139 | struct rb_node *parent = *node; | |
140 | struct wakelock *wl; | |
141 | ||
142 | while (*node) { | |
143 | int diff; | |
144 | ||
145 | parent = *node; | |
146 | wl = rb_entry(*node, struct wakelock, node); | |
147 | diff = strncmp(name, wl->name, len); | |
148 | if (diff == 0) { | |
149 | if (wl->name[len]) | |
150 | diff = -1; | |
151 | else | |
152 | return wl; | |
153 | } | |
154 | if (diff < 0) | |
155 | node = &(*node)->rb_left; | |
156 | else | |
157 | node = &(*node)->rb_right; | |
158 | } | |
159 | if (!add_if_not_found) | |
160 | return ERR_PTR(-EINVAL); | |
161 | ||
c73893e2 | 162 | if (wakelocks_limit_exceeded()) |
b86ff982 RW |
163 | return ERR_PTR(-ENOSPC); |
164 | ||
165 | /* Not found, we have to add a new one. */ | |
166 | wl = kzalloc(sizeof(*wl), GFP_KERNEL); | |
167 | if (!wl) | |
168 | return ERR_PTR(-ENOMEM); | |
169 | ||
170 | wl->name = kstrndup(name, len, GFP_KERNEL); | |
171 | if (!wl->name) { | |
172 | kfree(wl); | |
173 | return ERR_PTR(-ENOMEM); | |
174 | } | |
175 | wl->ws.name = wl->name; | |
176 | wakeup_source_add(&wl->ws); | |
177 | rb_link_node(&wl->node, parent, node); | |
178 | rb_insert_color(&wl->node, &wakelocks_tree); | |
4e585d25 | 179 | wakelocks_lru_add(wl); |
c73893e2 | 180 | increment_wakelocks_number(); |
b86ff982 RW |
181 | return wl; |
182 | } | |
183 | ||
184 | int pm_wake_lock(const char *buf) | |
185 | { | |
186 | const char *str = buf; | |
187 | struct wakelock *wl; | |
188 | u64 timeout_ns = 0; | |
189 | size_t len; | |
190 | int ret = 0; | |
191 | ||
11388c87 RW |
192 | if (!capable(CAP_BLOCK_SUSPEND)) |
193 | return -EPERM; | |
194 | ||
b86ff982 RW |
195 | while (*str && !isspace(*str)) |
196 | str++; | |
197 | ||
198 | len = str - buf; | |
199 | if (!len) | |
200 | return -EINVAL; | |
201 | ||
202 | if (*str && *str != '\n') { | |
203 | /* Find out if there's a valid timeout string appended. */ | |
204 | ret = kstrtou64(skip_spaces(str), 10, &timeout_ns); | |
205 | if (ret) | |
206 | return -EINVAL; | |
207 | } | |
208 | ||
209 | mutex_lock(&wakelocks_lock); | |
210 | ||
211 | wl = wakelock_lookup_add(buf, len, true); | |
212 | if (IS_ERR(wl)) { | |
213 | ret = PTR_ERR(wl); | |
214 | goto out; | |
215 | } | |
216 | if (timeout_ns) { | |
217 | u64 timeout_ms = timeout_ns + NSEC_PER_MSEC - 1; | |
218 | ||
219 | do_div(timeout_ms, NSEC_PER_MSEC); | |
220 | __pm_wakeup_event(&wl->ws, timeout_ms); | |
221 | } else { | |
222 | __pm_stay_awake(&wl->ws); | |
223 | } | |
224 | ||
4e585d25 | 225 | wakelocks_lru_most_recent(wl); |
b86ff982 RW |
226 | |
227 | out: | |
228 | mutex_unlock(&wakelocks_lock); | |
229 | return ret; | |
230 | } | |
231 | ||
b86ff982 RW |
232 | int pm_wake_unlock(const char *buf) |
233 | { | |
234 | struct wakelock *wl; | |
235 | size_t len; | |
236 | int ret = 0; | |
237 | ||
11388c87 RW |
238 | if (!capable(CAP_BLOCK_SUSPEND)) |
239 | return -EPERM; | |
240 | ||
b86ff982 RW |
241 | len = strlen(buf); |
242 | if (!len) | |
243 | return -EINVAL; | |
244 | ||
245 | if (buf[len-1] == '\n') | |
246 | len--; | |
247 | ||
248 | if (!len) | |
249 | return -EINVAL; | |
250 | ||
251 | mutex_lock(&wakelocks_lock); | |
252 | ||
253 | wl = wakelock_lookup_add(buf, len, false); | |
254 | if (IS_ERR(wl)) { | |
255 | ret = PTR_ERR(wl); | |
256 | goto out; | |
257 | } | |
258 | __pm_relax(&wl->ws); | |
4e585d25 RW |
259 | |
260 | wakelocks_lru_most_recent(wl); | |
261 | wakelocks_gc(); | |
b86ff982 RW |
262 | |
263 | out: | |
264 | mutex_unlock(&wakelocks_lock); | |
265 | return ret; | |
266 | } |