Rafael J. Wysocki | b86ff982 | 2012-04-29 22:53:42 +0200 | [diff] [blame] | 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 | |
Rafael J. Wysocki | 11388c8 | 2012-07-19 00:00:58 +0200 | [diff] [blame] | 12 | #include <linux/capability.h> |
Rafael J. Wysocki | b86ff982 | 2012-04-29 22:53:42 +0200 | [diff] [blame] | 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 | |
Rafael J. Wysocki | b86ff982 | 2012-04-29 22:53:42 +0200 | [diff] [blame] | 21 | static DEFINE_MUTEX(wakelocks_lock); |
| 22 | |
| 23 | struct wakelock { |
| 24 | char *name; |
| 25 | struct rb_node node; |
| 26 | struct wakeup_source ws; |
Rafael J. Wysocki | 4e585d2 | 2012-05-05 21:57:28 +0200 | [diff] [blame] | 27 | #ifdef CONFIG_PM_WAKELOCKS_GC |
Rafael J. Wysocki | b86ff982 | 2012-04-29 22:53:42 +0200 | [diff] [blame] | 28 | struct list_head lru; |
Rafael J. Wysocki | 4e585d2 | 2012-05-05 21:57:28 +0200 | [diff] [blame] | 29 | #endif |
Rafael J. Wysocki | b86ff982 | 2012-04-29 22:53:42 +0200 | [diff] [blame] | 30 | }; |
| 31 | |
| 32 | static struct rb_root wakelocks_tree = RB_ROOT; |
Rafael J. Wysocki | b86ff982 | 2012-04-29 22:53:42 +0200 | [diff] [blame] | 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 | |
Rafael J. Wysocki | c73893e | 2012-05-05 21:57:20 +0200 | [diff] [blame] | 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 | |
Rafael J. Wysocki | 4e585d2 | 2012-05-05 21:57:28 +0200 | [diff] [blame] | 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 | |
Rafael J. Wysocki | b86ff982 | 2012-04-29 22:53:42 +0200 | [diff] [blame] | 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 | |
Rafael J. Wysocki | c73893e | 2012-05-05 21:57:20 +0200 | [diff] [blame] | 162 | if (wakelocks_limit_exceeded()) |
Rafael J. Wysocki | b86ff982 | 2012-04-29 22:53:42 +0200 | [diff] [blame] | 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); |
Rafael J. Wysocki | 4e585d2 | 2012-05-05 21:57:28 +0200 | [diff] [blame] | 179 | wakelocks_lru_add(wl); |
Rafael J. Wysocki | c73893e | 2012-05-05 21:57:20 +0200 | [diff] [blame] | 180 | increment_wakelocks_number(); |
Rafael J. Wysocki | b86ff982 | 2012-04-29 22:53:42 +0200 | [diff] [blame] | 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 | |
Rafael J. Wysocki | 11388c8 | 2012-07-19 00:00:58 +0200 | [diff] [blame] | 192 | if (!capable(CAP_BLOCK_SUSPEND)) |
| 193 | return -EPERM; |
| 194 | |
Rafael J. Wysocki | b86ff982 | 2012-04-29 22:53:42 +0200 | [diff] [blame] | 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 | |
Rafael J. Wysocki | 4e585d2 | 2012-05-05 21:57:28 +0200 | [diff] [blame] | 225 | wakelocks_lru_most_recent(wl); |
Rafael J. Wysocki | b86ff982 | 2012-04-29 22:53:42 +0200 | [diff] [blame] | 226 | |
| 227 | out: |
| 228 | mutex_unlock(&wakelocks_lock); |
| 229 | return ret; |
| 230 | } |
| 231 | |
Rafael J. Wysocki | b86ff982 | 2012-04-29 22:53:42 +0200 | [diff] [blame] | 232 | int pm_wake_unlock(const char *buf) |
| 233 | { |
| 234 | struct wakelock *wl; |
| 235 | size_t len; |
| 236 | int ret = 0; |
| 237 | |
Rafael J. Wysocki | 11388c8 | 2012-07-19 00:00:58 +0200 | [diff] [blame] | 238 | if (!capable(CAP_BLOCK_SUSPEND)) |
| 239 | return -EPERM; |
| 240 | |
Rafael J. Wysocki | b86ff982 | 2012-04-29 22:53:42 +0200 | [diff] [blame] | 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); |
Rafael J. Wysocki | 4e585d2 | 2012-05-05 21:57:28 +0200 | [diff] [blame] | 259 | |
| 260 | wakelocks_lru_most_recent(wl); |
| 261 | wakelocks_gc(); |
Rafael J. Wysocki | b86ff982 | 2012-04-29 22:53:42 +0200 | [diff] [blame] | 262 | |
| 263 | out: |
| 264 | mutex_unlock(&wakelocks_lock); |
| 265 | return ret; |
| 266 | } |