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1da177e4 LT |
1 | /* |
2 | * kernel/power/main.c - PM subsystem core functionality. | |
3 | * | |
4 | * Copyright (c) 2003 Patrick Mochel | |
5 | * Copyright (c) 2003 Open Source Development Lab | |
6 | * | |
7 | * This file is released under the GPLv2 | |
8 | * | |
9 | */ | |
10 | ||
1da177e4 LT |
11 | #include <linux/kobject.h> |
12 | #include <linux/string.h> | |
c5c6ba4e | 13 | #include <linux/resume-trace.h> |
5e928f77 | 14 | #include <linux/workqueue.h> |
1da177e4 LT |
15 | |
16 | #include "power.h" | |
17 | ||
a6d70980 | 18 | DEFINE_MUTEX(pm_mutex); |
1da177e4 | 19 | |
cd51e61c RW |
20 | #ifdef CONFIG_PM_SLEEP |
21 | ||
82525756 AS |
22 | /* Routines for PM-transition notifications */ |
23 | ||
24 | static BLOCKING_NOTIFIER_HEAD(pm_chain_head); | |
25 | ||
26 | int register_pm_notifier(struct notifier_block *nb) | |
27 | { | |
28 | return blocking_notifier_chain_register(&pm_chain_head, nb); | |
29 | } | |
30 | EXPORT_SYMBOL_GPL(register_pm_notifier); | |
31 | ||
32 | int unregister_pm_notifier(struct notifier_block *nb) | |
33 | { | |
34 | return blocking_notifier_chain_unregister(&pm_chain_head, nb); | |
35 | } | |
36 | EXPORT_SYMBOL_GPL(unregister_pm_notifier); | |
37 | ||
38 | int pm_notifier_call_chain(unsigned long val) | |
39 | { | |
40 | return (blocking_notifier_call_chain(&pm_chain_head, val, NULL) | |
41 | == NOTIFY_BAD) ? -EINVAL : 0; | |
42 | } | |
43 | ||
0e06b4a8 RW |
44 | /* If set, devices may be suspended and resumed asynchronously. */ |
45 | int pm_async_enabled = 1; | |
46 | ||
47 | static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr, | |
48 | char *buf) | |
49 | { | |
50 | return sprintf(buf, "%d\n", pm_async_enabled); | |
51 | } | |
52 | ||
53 | static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr, | |
54 | const char *buf, size_t n) | |
55 | { | |
56 | unsigned long val; | |
57 | ||
58 | if (strict_strtoul(buf, 10, &val)) | |
59 | return -EINVAL; | |
60 | ||
61 | if (val > 1) | |
62 | return -EINVAL; | |
63 | ||
64 | pm_async_enabled = val; | |
65 | return n; | |
66 | } | |
67 | ||
68 | power_attr(pm_async); | |
69 | ||
0e7d56e3 RW |
70 | #ifdef CONFIG_PM_DEBUG |
71 | int pm_test_level = TEST_NONE; | |
72 | ||
0e7d56e3 RW |
73 | static const char * const pm_tests[__TEST_AFTER_LAST] = { |
74 | [TEST_NONE] = "none", | |
75 | [TEST_CORE] = "core", | |
76 | [TEST_CPUS] = "processors", | |
77 | [TEST_PLATFORM] = "platform", | |
78 | [TEST_DEVICES] = "devices", | |
79 | [TEST_FREEZER] = "freezer", | |
80 | }; | |
81 | ||
039a75c6 RW |
82 | static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr, |
83 | char *buf) | |
0e7d56e3 RW |
84 | { |
85 | char *s = buf; | |
86 | int level; | |
87 | ||
88 | for (level = TEST_FIRST; level <= TEST_MAX; level++) | |
89 | if (pm_tests[level]) { | |
90 | if (level == pm_test_level) | |
91 | s += sprintf(s, "[%s] ", pm_tests[level]); | |
92 | else | |
93 | s += sprintf(s, "%s ", pm_tests[level]); | |
94 | } | |
95 | ||
96 | if (s != buf) | |
97 | /* convert the last space to a newline */ | |
98 | *(s-1) = '\n'; | |
99 | ||
100 | return (s - buf); | |
101 | } | |
102 | ||
039a75c6 RW |
103 | static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr, |
104 | const char *buf, size_t n) | |
0e7d56e3 RW |
105 | { |
106 | const char * const *s; | |
107 | int level; | |
108 | char *p; | |
109 | int len; | |
110 | int error = -EINVAL; | |
111 | ||
112 | p = memchr(buf, '\n', n); | |
113 | len = p ? p - buf : n; | |
114 | ||
115 | mutex_lock(&pm_mutex); | |
116 | ||
117 | level = TEST_FIRST; | |
118 | for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++) | |
119 | if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) { | |
120 | pm_test_level = level; | |
121 | error = 0; | |
122 | break; | |
123 | } | |
124 | ||
125 | mutex_unlock(&pm_mutex); | |
126 | ||
127 | return error ? error : n; | |
128 | } | |
129 | ||
130 | power_attr(pm_test); | |
091d71e0 | 131 | #endif /* CONFIG_PM_DEBUG */ |
0e7d56e3 | 132 | |
7671b8ae | 133 | #endif /* CONFIG_PM_SLEEP */ |
039a75c6 | 134 | |
d76e15fb | 135 | struct kobject *power_kobj; |
1da177e4 LT |
136 | |
137 | /** | |
138 | * state - control system power state. | |
139 | * | |
140 | * show() returns what states are supported, which is hard-coded to | |
141 | * 'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and | |
142 | * 'disk' (Suspend-to-Disk). | |
143 | * | |
144 | * store() accepts one of those strings, translates it into the | |
145 | * proper enumerated value, and initiates a suspend transition. | |
146 | */ | |
386f275f KS |
147 | static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr, |
148 | char *buf) | |
1da177e4 | 149 | { |
296699de RW |
150 | char *s = buf; |
151 | #ifdef CONFIG_SUSPEND | |
1da177e4 | 152 | int i; |
1da177e4 LT |
153 | |
154 | for (i = 0; i < PM_SUSPEND_MAX; i++) { | |
123d3c13 PM |
155 | if (pm_states[i] && valid_state(i)) |
156 | s += sprintf(s,"%s ", pm_states[i]); | |
1da177e4 | 157 | } |
296699de | 158 | #endif |
b0cb1a19 | 159 | #ifdef CONFIG_HIBERNATION |
a3d25c27 RW |
160 | s += sprintf(s, "%s\n", "disk"); |
161 | #else | |
162 | if (s != buf) | |
163 | /* convert the last space to a newline */ | |
164 | *(s-1) = '\n'; | |
165 | #endif | |
1da177e4 LT |
166 | return (s - buf); |
167 | } | |
168 | ||
386f275f KS |
169 | static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr, |
170 | const char *buf, size_t n) | |
1da177e4 | 171 | { |
296699de | 172 | #ifdef CONFIG_SUSPEND |
1da177e4 | 173 | suspend_state_t state = PM_SUSPEND_STANDBY; |
3b364b8d | 174 | const char * const *s; |
296699de | 175 | #endif |
1da177e4 | 176 | char *p; |
1da177e4 | 177 | int len; |
296699de | 178 | int error = -EINVAL; |
1da177e4 LT |
179 | |
180 | p = memchr(buf, '\n', n); | |
181 | len = p ? p - buf : n; | |
182 | ||
a3d25c27 | 183 | /* First, check if we are requested to hibernate */ |
8d98a690 | 184 | if (len == 4 && !strncmp(buf, "disk", len)) { |
a3d25c27 | 185 | error = hibernate(); |
296699de | 186 | goto Exit; |
a3d25c27 RW |
187 | } |
188 | ||
296699de | 189 | #ifdef CONFIG_SUSPEND |
1da177e4 | 190 | for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) { |
8d98a690 | 191 | if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) |
1da177e4 LT |
192 | break; |
193 | } | |
47bb7899 | 194 | if (state < PM_SUSPEND_MAX && *s) |
1da177e4 | 195 | error = enter_state(state); |
296699de RW |
196 | #endif |
197 | ||
198 | Exit: | |
1da177e4 LT |
199 | return error ? error : n; |
200 | } | |
201 | ||
202 | power_attr(state); | |
203 | ||
c125e96f RW |
204 | #ifdef CONFIG_PM_SLEEP |
205 | /* | |
206 | * The 'wakeup_count' attribute, along with the functions defined in | |
207 | * drivers/base/power/wakeup.c, provides a means by which wakeup events can be | |
208 | * handled in a non-racy way. | |
209 | * | |
210 | * If a wakeup event occurs when the system is in a sleep state, it simply is | |
211 | * woken up. In turn, if an event that would wake the system up from a sleep | |
212 | * state occurs when it is undergoing a transition to that sleep state, the | |
213 | * transition should be aborted. Moreover, if such an event occurs when the | |
214 | * system is in the working state, an attempt to start a transition to the | |
215 | * given sleep state should fail during certain period after the detection of | |
216 | * the event. Using the 'state' attribute alone is not sufficient to satisfy | |
217 | * these requirements, because a wakeup event may occur exactly when 'state' | |
218 | * is being written to and may be delivered to user space right before it is | |
219 | * frozen, so the event will remain only partially processed until the system is | |
220 | * woken up by another event. In particular, it won't cause the transition to | |
221 | * a sleep state to be aborted. | |
222 | * | |
223 | * This difficulty may be overcome if user space uses 'wakeup_count' before | |
224 | * writing to 'state'. It first should read from 'wakeup_count' and store | |
225 | * the read value. Then, after carrying out its own preparations for the system | |
226 | * transition to a sleep state, it should write the stored value to | |
25985edc | 227 | * 'wakeup_count'. If that fails, at least one wakeup event has occurred since |
c125e96f RW |
228 | * 'wakeup_count' was read and 'state' should not be written to. Otherwise, it |
229 | * is allowed to write to 'state', but the transition will be aborted if there | |
230 | * are any wakeup events detected after 'wakeup_count' was written to. | |
231 | */ | |
232 | ||
233 | static ssize_t wakeup_count_show(struct kobject *kobj, | |
234 | struct kobj_attribute *attr, | |
235 | char *buf) | |
236 | { | |
074037ec | 237 | unsigned int val; |
c125e96f | 238 | |
074037ec | 239 | return pm_get_wakeup_count(&val) ? sprintf(buf, "%u\n", val) : -EINTR; |
c125e96f RW |
240 | } |
241 | ||
242 | static ssize_t wakeup_count_store(struct kobject *kobj, | |
243 | struct kobj_attribute *attr, | |
244 | const char *buf, size_t n) | |
245 | { | |
074037ec | 246 | unsigned int val; |
c125e96f | 247 | |
074037ec | 248 | if (sscanf(buf, "%u", &val) == 1) { |
c125e96f RW |
249 | if (pm_save_wakeup_count(val)) |
250 | return n; | |
251 | } | |
252 | return -EINVAL; | |
253 | } | |
254 | ||
255 | power_attr(wakeup_count); | |
256 | #endif /* CONFIG_PM_SLEEP */ | |
257 | ||
c5c6ba4e RW |
258 | #ifdef CONFIG_PM_TRACE |
259 | int pm_trace_enabled; | |
260 | ||
386f275f KS |
261 | static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr, |
262 | char *buf) | |
c5c6ba4e RW |
263 | { |
264 | return sprintf(buf, "%d\n", pm_trace_enabled); | |
265 | } | |
266 | ||
267 | static ssize_t | |
386f275f KS |
268 | pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr, |
269 | const char *buf, size_t n) | |
c5c6ba4e RW |
270 | { |
271 | int val; | |
272 | ||
273 | if (sscanf(buf, "%d", &val) == 1) { | |
274 | pm_trace_enabled = !!val; | |
275 | return n; | |
276 | } | |
277 | return -EINVAL; | |
278 | } | |
279 | ||
280 | power_attr(pm_trace); | |
d33ac60b JH |
281 | |
282 | static ssize_t pm_trace_dev_match_show(struct kobject *kobj, | |
283 | struct kobj_attribute *attr, | |
284 | char *buf) | |
285 | { | |
286 | return show_trace_dev_match(buf, PAGE_SIZE); | |
287 | } | |
288 | ||
289 | static ssize_t | |
290 | pm_trace_dev_match_store(struct kobject *kobj, struct kobj_attribute *attr, | |
291 | const char *buf, size_t n) | |
292 | { | |
293 | return -EINVAL; | |
294 | } | |
295 | ||
296 | power_attr(pm_trace_dev_match); | |
297 | ||
0e7d56e3 | 298 | #endif /* CONFIG_PM_TRACE */ |
c5c6ba4e RW |
299 | |
300 | static struct attribute * g[] = { | |
301 | &state_attr.attr, | |
0e7d56e3 | 302 | #ifdef CONFIG_PM_TRACE |
c5c6ba4e | 303 | &pm_trace_attr.attr, |
d33ac60b | 304 | &pm_trace_dev_match_attr.attr, |
0e7d56e3 | 305 | #endif |
0e06b4a8 RW |
306 | #ifdef CONFIG_PM_SLEEP |
307 | &pm_async_attr.attr, | |
c125e96f | 308 | &wakeup_count_attr.attr, |
0e06b4a8 | 309 | #ifdef CONFIG_PM_DEBUG |
0e7d56e3 | 310 | &pm_test_attr.attr, |
0e06b4a8 | 311 | #endif |
0e7d56e3 | 312 | #endif |
c5c6ba4e RW |
313 | NULL, |
314 | }; | |
1da177e4 LT |
315 | |
316 | static struct attribute_group attr_group = { | |
317 | .attrs = g, | |
318 | }; | |
319 | ||
5e928f77 RW |
320 | #ifdef CONFIG_PM_RUNTIME |
321 | struct workqueue_struct *pm_wq; | |
7b199ca2 | 322 | EXPORT_SYMBOL_GPL(pm_wq); |
5e928f77 RW |
323 | |
324 | static int __init pm_start_workqueue(void) | |
325 | { | |
58a69cb4 | 326 | pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0); |
5e928f77 RW |
327 | |
328 | return pm_wq ? 0 : -ENOMEM; | |
329 | } | |
330 | #else | |
331 | static inline int pm_start_workqueue(void) { return 0; } | |
332 | #endif | |
333 | ||
1da177e4 LT |
334 | static int __init pm_init(void) |
335 | { | |
5e928f77 RW |
336 | int error = pm_start_workqueue(); |
337 | if (error) | |
338 | return error; | |
ac5c24ec | 339 | hibernate_image_size_init(); |
d76e15fb GKH |
340 | power_kobj = kobject_create_and_add("power", NULL); |
341 | if (!power_kobj) | |
039a5dcd | 342 | return -ENOMEM; |
d76e15fb | 343 | return sysfs_create_group(power_kobj, &attr_group); |
1da177e4 LT |
344 | } |
345 | ||
346 | core_initcall(pm_init); |