2 * kernel/power/wakelock.c
4 * User space wakeup sources support.
6 * Copyright (C) 2012 Rafael J. Wysocki <rjw@sisk.pl>
8 * This code is based on the analogous interface allowing user space to
9 * manipulate wakelocks on Android.
12 #include <linux/ctype.h>
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/hrtimer.h>
16 #include <linux/list.h>
17 #include <linux/rbtree.h>
18 #include <linux/slab.h>
20 static DEFINE_MUTEX(wakelocks_lock);
25 struct wakeup_source ws;
26 #ifdef CONFIG_PM_WAKELOCKS_GC
31 static struct rb_root wakelocks_tree = RB_ROOT;
33 ssize_t pm_show_wakelocks(char *buf, bool show_active)
38 char *end = buf + PAGE_SIZE;
40 mutex_lock(&wakelocks_lock);
42 for (node = rb_first(&wakelocks_tree); node; node = rb_next(node)) {
43 wl = rb_entry(node, struct wakelock, node);
44 if (wl->ws.active == show_active)
45 str += scnprintf(str, end - str, "%s ", wl->name);
50 str += scnprintf(str, end - str, "\n");
52 mutex_unlock(&wakelocks_lock);
56 #if CONFIG_PM_WAKELOCKS_LIMIT > 0
57 static unsigned int number_of_wakelocks;
59 static inline bool wakelocks_limit_exceeded(void)
61 return number_of_wakelocks > CONFIG_PM_WAKELOCKS_LIMIT;
64 static inline void increment_wakelocks_number(void)
66 number_of_wakelocks++;
69 static inline void decrement_wakelocks_number(void)
71 number_of_wakelocks--;
73 #else /* CONFIG_PM_WAKELOCKS_LIMIT = 0 */
74 static inline bool wakelocks_limit_exceeded(void) { return false; }
75 static inline void increment_wakelocks_number(void) {}
76 static inline void decrement_wakelocks_number(void) {}
77 #endif /* CONFIG_PM_WAKELOCKS_LIMIT */
79 #ifdef CONFIG_PM_WAKELOCKS_GC
80 #define WL_GC_COUNT_MAX 100
81 #define WL_GC_TIME_SEC 300
83 static LIST_HEAD(wakelocks_lru_list);
84 static unsigned int wakelocks_gc_count;
86 static inline void wakelocks_lru_add(struct wakelock *wl)
88 list_add(&wl->lru, &wakelocks_lru_list);
91 static inline void wakelocks_lru_most_recent(struct wakelock *wl)
93 list_move(&wl->lru, &wakelocks_lru_list);
96 static void wakelocks_gc(void)
98 struct wakelock *wl, *aux;
101 if (++wakelocks_gc_count <= WL_GC_COUNT_MAX)
105 list_for_each_entry_safe_reverse(wl, aux, &wakelocks_lru_list, lru) {
109 spin_lock_irq(&wl->ws.lock);
110 idle_time_ns = ktime_to_ns(ktime_sub(now, wl->ws.last_time));
111 active = wl->ws.active;
112 spin_unlock_irq(&wl->ws.lock);
114 if (idle_time_ns < ((u64)WL_GC_TIME_SEC * NSEC_PER_SEC))
118 wakeup_source_remove(&wl->ws);
119 rb_erase(&wl->node, &wakelocks_tree);
123 decrement_wakelocks_number();
126 wakelocks_gc_count = 0;
128 #else /* !CONFIG_PM_WAKELOCKS_GC */
129 static inline void wakelocks_lru_add(struct wakelock *wl) {}
130 static inline void wakelocks_lru_most_recent(struct wakelock *wl) {}
131 static inline void wakelocks_gc(void) {}
132 #endif /* !CONFIG_PM_WAKELOCKS_GC */
134 static struct wakelock *wakelock_lookup_add(const char *name, size_t len,
135 bool add_if_not_found)
137 struct rb_node **node = &wakelocks_tree.rb_node;
138 struct rb_node *parent = *node;
145 wl = rb_entry(*node, struct wakelock, node);
146 diff = strncmp(name, wl->name, len);
154 node = &(*node)->rb_left;
156 node = &(*node)->rb_right;
158 if (!add_if_not_found)
159 return ERR_PTR(-EINVAL);
161 if (wakelocks_limit_exceeded())
162 return ERR_PTR(-ENOSPC);
164 /* Not found, we have to add a new one. */
165 wl = kzalloc(sizeof(*wl), GFP_KERNEL);
167 return ERR_PTR(-ENOMEM);
169 wl->name = kstrndup(name, len, GFP_KERNEL);
172 return ERR_PTR(-ENOMEM);
174 wl->ws.name = wl->name;
175 wakeup_source_add(&wl->ws);
176 rb_link_node(&wl->node, parent, node);
177 rb_insert_color(&wl->node, &wakelocks_tree);
178 wakelocks_lru_add(wl);
179 increment_wakelocks_number();
183 int pm_wake_lock(const char *buf)
185 const char *str = buf;
191 while (*str && !isspace(*str))
198 if (*str && *str != '\n') {
199 /* Find out if there's a valid timeout string appended. */
200 ret = kstrtou64(skip_spaces(str), 10, &timeout_ns);
205 mutex_lock(&wakelocks_lock);
207 wl = wakelock_lookup_add(buf, len, true);
213 u64 timeout_ms = timeout_ns + NSEC_PER_MSEC - 1;
215 do_div(timeout_ms, NSEC_PER_MSEC);
216 __pm_wakeup_event(&wl->ws, timeout_ms);
218 __pm_stay_awake(&wl->ws);
221 wakelocks_lru_most_recent(wl);
224 mutex_unlock(&wakelocks_lock);
228 int pm_wake_unlock(const char *buf)
238 if (buf[len-1] == '\n')
244 mutex_lock(&wakelocks_lock);
246 wl = wakelock_lookup_add(buf, len, false);
253 wakelocks_lru_most_recent(wl);
257 mutex_unlock(&wakelocks_lock);