~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/kernel/power/wakelock.c

Version: ~ [ linux-5.4 ] ~ [ linux-5.3.13 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.86 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.156 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.203 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.202 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.78 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 
 12 #include <linux/capability.h>
 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 #include <linux/workqueue.h>
 21 
 22 #include "power.h"
 23 
 24 static DEFINE_MUTEX(wakelocks_lock);
 25 
 26 struct wakelock {
 27         char                    *name;
 28         struct rb_node          node;
 29         struct wakeup_source    ws;
 30 #ifdef CONFIG_PM_WAKELOCKS_GC
 31         struct list_head        lru;
 32 #endif
 33 };
 34 
 35 static struct rb_root wakelocks_tree = RB_ROOT;
 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 
 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 
 83 #ifdef CONFIG_PM_WAKELOCKS_GC
 84 #define WL_GC_COUNT_MAX 100
 85 #define WL_GC_TIME_SEC  300
 86 
 87 static void __wakelocks_gc(struct work_struct *work);
 88 static LIST_HEAD(wakelocks_lru_list);
 89 static DECLARE_WORK(wakelock_work, __wakelocks_gc);
 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 
102 static void __wakelocks_gc(struct work_struct *work)
103 {
104         struct wakelock *wl, *aux;
105         ktime_t now;
106 
107         mutex_lock(&wakelocks_lock);
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;
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);
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 
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 
176         if (wakelocks_limit_exceeded())
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);
193         wakelocks_lru_add(wl);
194         increment_wakelocks_number();
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 
206         if (!capable(CAP_BLOCK_SUSPEND))
207                 return -EPERM;
208 
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 
239         wakelocks_lru_most_recent(wl);
240 
241  out:
242         mutex_unlock(&wakelocks_lock);
243         return ret;
244 }
245 
246 int pm_wake_unlock(const char *buf)
247 {
248         struct wakelock *wl;
249         size_t len;
250         int ret = 0;
251 
252         if (!capable(CAP_BLOCK_SUSPEND))
253                 return -EPERM;
254 
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);
273 
274         wakelocks_lru_most_recent(wl);
275         wakelocks_gc();
276 
277  out:
278         mutex_unlock(&wakelocks_lock);
279         return ret;
280 }
281 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp