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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 | ||
6c5be291 RK |
21 | #include "power.h" |
22 | ||
b86ff982 RW |
23 | static DEFINE_MUTEX(wakelocks_lock); |
24 | ||
25 | struct wakelock { | |
26 | char *name; | |
27 | struct rb_node node; | |
28 | struct wakeup_source ws; | |
4e585d25 | 29 | #ifdef CONFIG_PM_WAKELOCKS_GC |
b86ff982 | 30 | struct list_head lru; |
4e585d25 | 31 | #endif |
b86ff982 RW |
32 | }; |
33 | ||
34 | static struct rb_root wakelocks_tree = RB_ROOT; | |
b86ff982 RW |
35 | |
36 | ssize_t pm_show_wakelocks(char *buf, bool show_active) | |
37 | { | |
38 | struct rb_node *node; | |
39 | struct wakelock *wl; | |
40 | char *str = buf; | |
41 | char *end = buf + PAGE_SIZE; | |
42 | ||
43 | mutex_lock(&wakelocks_lock); | |
44 | ||
45 | for (node = rb_first(&wakelocks_tree); node; node = rb_next(node)) { | |
46 | wl = rb_entry(node, struct wakelock, node); | |
47 | if (wl->ws.active == show_active) | |
48 | str += scnprintf(str, end - str, "%s ", wl->name); | |
49 | } | |
50 | if (str > buf) | |
51 | str--; | |
52 | ||
53 | str += scnprintf(str, end - str, "\n"); | |
54 | ||
55 | mutex_unlock(&wakelocks_lock); | |
56 | return (str - buf); | |
57 | } | |
58 | ||
c73893e2 RW |
59 | #if CONFIG_PM_WAKELOCKS_LIMIT > 0 |
60 | static unsigned int number_of_wakelocks; | |
61 | ||
62 | static inline bool wakelocks_limit_exceeded(void) | |
63 | { | |
64 | return number_of_wakelocks > CONFIG_PM_WAKELOCKS_LIMIT; | |
65 | } | |
66 | ||
67 | static inline void increment_wakelocks_number(void) | |
68 | { | |
69 | number_of_wakelocks++; | |
70 | } | |
71 | ||
72 | static inline void decrement_wakelocks_number(void) | |
73 | { | |
74 | number_of_wakelocks--; | |
75 | } | |
76 | #else /* CONFIG_PM_WAKELOCKS_LIMIT = 0 */ | |
77 | static inline bool wakelocks_limit_exceeded(void) { return false; } | |
78 | static inline void increment_wakelocks_number(void) {} | |
79 | static inline void decrement_wakelocks_number(void) {} | |
80 | #endif /* CONFIG_PM_WAKELOCKS_LIMIT */ | |
81 | ||
4e585d25 RW |
82 | #ifdef CONFIG_PM_WAKELOCKS_GC |
83 | #define WL_GC_COUNT_MAX 100 | |
84 | #define WL_GC_TIME_SEC 300 | |
85 | ||
86 | static LIST_HEAD(wakelocks_lru_list); | |
87 | static unsigned int wakelocks_gc_count; | |
88 | ||
89 | static inline void wakelocks_lru_add(struct wakelock *wl) | |
90 | { | |
91 | list_add(&wl->lru, &wakelocks_lru_list); | |
92 | } | |
93 | ||
94 | static inline void wakelocks_lru_most_recent(struct wakelock *wl) | |
95 | { | |
96 | list_move(&wl->lru, &wakelocks_lru_list); | |
97 | } | |
98 | ||
99 | static void wakelocks_gc(void) | |
100 | { | |
101 | struct wakelock *wl, *aux; | |
102 | ktime_t now; | |
103 | ||
104 | if (++wakelocks_gc_count <= WL_GC_COUNT_MAX) | |
105 | return; | |
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 | ||
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); | |
116 | ||
117 | if (idle_time_ns < ((u64)WL_GC_TIME_SEC * NSEC_PER_SEC)) | |
118 | break; | |
119 | ||
120 | if (!active) { | |
121 | wakeup_source_remove(&wl->ws); | |
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; | |
130 | } | |
131 | #else /* !CONFIG_PM_WAKELOCKS_GC */ | |
132 | static inline void wakelocks_lru_add(struct wakelock *wl) {} | |
133 | static inline void wakelocks_lru_most_recent(struct wakelock *wl) {} | |
134 | static inline void wakelocks_gc(void) {} | |
135 | #endif /* !CONFIG_PM_WAKELOCKS_GC */ | |
136 | ||
b86ff982 RW |
137 | static struct wakelock *wakelock_lookup_add(const char *name, size_t len, |
138 | bool add_if_not_found) | |
139 | { | |
140 | struct rb_node **node = &wakelocks_tree.rb_node; | |
141 | struct rb_node *parent = *node; | |
142 | struct wakelock *wl; | |
143 | ||
144 | while (*node) { | |
145 | int diff; | |
146 | ||
147 | parent = *node; | |
148 | wl = rb_entry(*node, struct wakelock, node); | |
149 | diff = strncmp(name, wl->name, len); | |
150 | if (diff == 0) { | |
151 | if (wl->name[len]) | |
152 | diff = -1; | |
153 | else | |
154 | return wl; | |
155 | } | |
156 | if (diff < 0) | |
157 | node = &(*node)->rb_left; | |
158 | else | |
159 | node = &(*node)->rb_right; | |
160 | } | |
161 | if (!add_if_not_found) | |
162 | return ERR_PTR(-EINVAL); | |
163 | ||
c73893e2 | 164 | if (wakelocks_limit_exceeded()) |
b86ff982 RW |
165 | return ERR_PTR(-ENOSPC); |
166 | ||
167 | /* Not found, we have to add a new one. */ | |
168 | wl = kzalloc(sizeof(*wl), GFP_KERNEL); | |
169 | if (!wl) | |
170 | return ERR_PTR(-ENOMEM); | |
171 | ||
172 | wl->name = kstrndup(name, len, GFP_KERNEL); | |
173 | if (!wl->name) { | |
174 | kfree(wl); | |
175 | return ERR_PTR(-ENOMEM); | |
176 | } | |
177 | wl->ws.name = wl->name; | |
178 | wakeup_source_add(&wl->ws); | |
179 | rb_link_node(&wl->node, parent, node); | |
180 | rb_insert_color(&wl->node, &wakelocks_tree); | |
4e585d25 | 181 | wakelocks_lru_add(wl); |
c73893e2 | 182 | increment_wakelocks_number(); |
b86ff982 RW |
183 | return wl; |
184 | } | |
185 | ||
186 | int pm_wake_lock(const char *buf) | |
187 | { | |
188 | const char *str = buf; | |
189 | struct wakelock *wl; | |
190 | u64 timeout_ns = 0; | |
191 | size_t len; | |
192 | int ret = 0; | |
193 | ||
11388c87 RW |
194 | if (!capable(CAP_BLOCK_SUSPEND)) |
195 | return -EPERM; | |
196 | ||
b86ff982 RW |
197 | while (*str && !isspace(*str)) |
198 | str++; | |
199 | ||
200 | len = str - buf; | |
201 | if (!len) | |
202 | return -EINVAL; | |
203 | ||
204 | if (*str && *str != '\n') { | |
205 | /* Find out if there's a valid timeout string appended. */ | |
206 | ret = kstrtou64(skip_spaces(str), 10, &timeout_ns); | |
207 | if (ret) | |
208 | return -EINVAL; | |
209 | } | |
210 | ||
211 | mutex_lock(&wakelocks_lock); | |
212 | ||
213 | wl = wakelock_lookup_add(buf, len, true); | |
214 | if (IS_ERR(wl)) { | |
215 | ret = PTR_ERR(wl); | |
216 | goto out; | |
217 | } | |
218 | if (timeout_ns) { | |
219 | u64 timeout_ms = timeout_ns + NSEC_PER_MSEC - 1; | |
220 | ||
221 | do_div(timeout_ms, NSEC_PER_MSEC); | |
222 | __pm_wakeup_event(&wl->ws, timeout_ms); | |
223 | } else { | |
224 | __pm_stay_awake(&wl->ws); | |
225 | } | |
226 | ||
4e585d25 | 227 | wakelocks_lru_most_recent(wl); |
b86ff982 RW |
228 | |
229 | out: | |
230 | mutex_unlock(&wakelocks_lock); | |
231 | return ret; | |
232 | } | |
233 | ||
b86ff982 RW |
234 | int pm_wake_unlock(const char *buf) |
235 | { | |
236 | struct wakelock *wl; | |
237 | size_t len; | |
238 | int ret = 0; | |
239 | ||
11388c87 RW |
240 | if (!capable(CAP_BLOCK_SUSPEND)) |
241 | return -EPERM; | |
242 | ||
b86ff982 RW |
243 | len = strlen(buf); |
244 | if (!len) | |
245 | return -EINVAL; | |
246 | ||
247 | if (buf[len-1] == '\n') | |
248 | len--; | |
249 | ||
250 | if (!len) | |
251 | return -EINVAL; | |
252 | ||
253 | mutex_lock(&wakelocks_lock); | |
254 | ||
255 | wl = wakelock_lookup_add(buf, len, false); | |
256 | if (IS_ERR(wl)) { | |
257 | ret = PTR_ERR(wl); | |
258 | goto out; | |
259 | } | |
260 | __pm_relax(&wl->ws); | |
4e585d25 RW |
261 | |
262 | wakelocks_lru_most_recent(wl); | |
263 | wakelocks_gc(); | |
b86ff982 RW |
264 | |
265 | out: | |
266 | mutex_unlock(&wakelocks_lock); | |
267 | return ret; | |
268 | } |