Commit | Line | Data |
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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 | ||
4cf30348 | 11 | #include <linux/module.h> |
1da177e4 LT |
12 | #include <linux/suspend.h> |
13 | #include <linux/kobject.h> | |
14 | #include <linux/string.h> | |
15 | #include <linux/delay.h> | |
16 | #include <linux/errno.h> | |
17 | #include <linux/init.h> | |
6cc07191 | 18 | #include <linux/console.h> |
e3920fb4 | 19 | #include <linux/cpu.h> |
c5c6ba4e | 20 | #include <linux/resume-trace.h> |
7dfb7103 | 21 | #include <linux/freezer.h> |
96177299 | 22 | #include <linux/vmstat.h> |
1da177e4 LT |
23 | |
24 | #include "power.h" | |
25 | ||
b10d9117 RW |
26 | BLOCKING_NOTIFIER_HEAD(pm_chain_head); |
27 | ||
5ae947ec DSL |
28 | /*This is just an arbitrary number */ |
29 | #define FREE_PAGE_NUMBER (100) | |
30 | ||
a6d70980 | 31 | DEFINE_MUTEX(pm_mutex); |
1da177e4 | 32 | |
123d3c13 | 33 | struct pm_ops *pm_ops; |
1da177e4 LT |
34 | |
35 | /** | |
36 | * pm_set_ops - Set the global power method table. | |
37 | * @ops: Pointer to ops structure. | |
38 | */ | |
39 | ||
40 | void pm_set_ops(struct pm_ops * ops) | |
41 | { | |
a6d70980 | 42 | mutex_lock(&pm_mutex); |
1da177e4 | 43 | pm_ops = ops; |
a6d70980 | 44 | mutex_unlock(&pm_mutex); |
1da177e4 LT |
45 | } |
46 | ||
e8c9c502 JB |
47 | /** |
48 | * pm_valid_only_mem - generic memory-only valid callback | |
49 | * | |
50 | * pm_ops drivers that implement mem suspend only and only need | |
51 | * to check for that in their .valid callback can use this instead | |
52 | * of rolling their own .valid callback. | |
53 | */ | |
54 | int pm_valid_only_mem(suspend_state_t state) | |
55 | { | |
56 | return state == PM_SUSPEND_MEM; | |
57 | } | |
58 | ||
59 | ||
e3c7db62 RW |
60 | static inline void pm_finish(suspend_state_t state) |
61 | { | |
62 | if (pm_ops->finish) | |
63 | pm_ops->finish(state); | |
64 | } | |
1da177e4 LT |
65 | |
66 | /** | |
67 | * suspend_prepare - Do prep work before entering low-power state. | |
1da177e4 | 68 | * |
6c961dfb RW |
69 | * This is common code that is called for each state that we're entering. |
70 | * Run suspend notifiers, allocate a console and stop all processes. | |
1da177e4 | 71 | */ |
6c961dfb | 72 | static int suspend_prepare(void) |
1da177e4 | 73 | { |
e3920fb4 | 74 | int error; |
5ae947ec | 75 | unsigned int free_pages; |
1da177e4 LT |
76 | |
77 | if (!pm_ops || !pm_ops->enter) | |
78 | return -EPERM; | |
79 | ||
b10d9117 RW |
80 | error = pm_notifier_call_chain(PM_SUSPEND_PREPARE); |
81 | if (error) | |
82 | goto Finish; | |
83 | ||
1da177e4 LT |
84 | pm_prepare_console(); |
85 | ||
86 | if (freeze_processes()) { | |
87 | error = -EAGAIN; | |
88 | goto Thaw; | |
89 | } | |
90 | ||
6c961dfb RW |
91 | free_pages = global_page_state(NR_FREE_PAGES); |
92 | if (free_pages < FREE_PAGE_NUMBER) { | |
5ae947ec DSL |
93 | pr_debug("PM: free some memory\n"); |
94 | shrink_all_memory(FREE_PAGE_NUMBER - free_pages); | |
95 | if (nr_free_pages() < FREE_PAGE_NUMBER) { | |
96 | error = -ENOMEM; | |
97 | printk(KERN_ERR "PM: No enough memory\n"); | |
5ae947ec DSL |
98 | } |
99 | } | |
e3c7db62 RW |
100 | if (!error) |
101 | return 0; | |
102 | ||
1da177e4 LT |
103 | Thaw: |
104 | thaw_processes(); | |
105 | pm_restore_console(); | |
b10d9117 RW |
106 | Finish: |
107 | pm_notifier_call_chain(PM_POST_SUSPEND); | |
1da177e4 LT |
108 | return error; |
109 | } | |
110 | ||
a53c46dc JB |
111 | /* default implementation */ |
112 | void __attribute__ ((weak)) arch_suspend_disable_irqs(void) | |
113 | { | |
114 | local_irq_disable(); | |
115 | } | |
116 | ||
117 | /* default implementation */ | |
118 | void __attribute__ ((weak)) arch_suspend_enable_irqs(void) | |
119 | { | |
120 | local_irq_enable(); | |
121 | } | |
1da177e4 | 122 | |
6c961dfb RW |
123 | /** |
124 | * suspend_enter - enter the desired system sleep state. | |
125 | * @state: state to enter | |
126 | * | |
127 | * This function should be called after devices have been suspended. | |
128 | */ | |
9b238205 | 129 | int suspend_enter(suspend_state_t state) |
1da177e4 LT |
130 | { |
131 | int error = 0; | |
1da177e4 | 132 | |
a53c46dc JB |
133 | arch_suspend_disable_irqs(); |
134 | BUG_ON(!irqs_disabled()); | |
1da177e4 LT |
135 | |
136 | if ((error = device_power_down(PMSG_SUSPEND))) { | |
137 | printk(KERN_ERR "Some devices failed to power down\n"); | |
138 | goto Done; | |
139 | } | |
140 | error = pm_ops->enter(state); | |
141 | device_power_up(); | |
142 | Done: | |
a53c46dc JB |
143 | arch_suspend_enable_irqs(); |
144 | BUG_ON(irqs_disabled()); | |
1da177e4 LT |
145 | return error; |
146 | } | |
147 | ||
6c961dfb RW |
148 | /** |
149 | * suspend_devices_and_enter - suspend devices and enter the desired system sleep | |
150 | * state. | |
151 | * @state: state to enter | |
152 | */ | |
153 | int suspend_devices_and_enter(suspend_state_t state) | |
154 | { | |
155 | int error; | |
156 | ||
157 | if (!pm_ops) | |
158 | return -ENOSYS; | |
159 | ||
160 | if (pm_ops->set_target) { | |
161 | error = pm_ops->set_target(state); | |
162 | if (error) | |
163 | return error; | |
164 | } | |
165 | suspend_console(); | |
166 | error = device_suspend(PMSG_SUSPEND); | |
167 | if (error) { | |
168 | printk(KERN_ERR "Some devices failed to suspend\n"); | |
169 | goto Resume_console; | |
170 | } | |
171 | if (pm_ops->prepare) { | |
172 | error = pm_ops->prepare(state); | |
173 | if (error) | |
174 | goto Resume_devices; | |
175 | } | |
176 | error = disable_nonboot_cpus(); | |
177 | if (!error) | |
178 | suspend_enter(state); | |
179 | ||
180 | enable_nonboot_cpus(); | |
181 | pm_finish(state); | |
182 | Resume_devices: | |
183 | device_resume(); | |
184 | Resume_console: | |
185 | resume_console(); | |
186 | return error; | |
187 | } | |
1da177e4 LT |
188 | |
189 | /** | |
190 | * suspend_finish - Do final work before exiting suspend sequence. | |
1da177e4 LT |
191 | * |
192 | * Call platform code to clean up, restart processes, and free the | |
193 | * console that we've allocated. This is not called for suspend-to-disk. | |
194 | */ | |
6c961dfb | 195 | static void suspend_finish(void) |
1da177e4 | 196 | { |
1da177e4 LT |
197 | thaw_processes(); |
198 | pm_restore_console(); | |
b10d9117 | 199 | pm_notifier_call_chain(PM_POST_SUSPEND); |
1da177e4 LT |
200 | } |
201 | ||
202 | ||
203 | ||
204 | ||
3b364b8d | 205 | static const char * const pm_states[PM_SUSPEND_MAX] = { |
1da177e4 LT |
206 | [PM_SUSPEND_STANDBY] = "standby", |
207 | [PM_SUSPEND_MEM] = "mem", | |
1da177e4 LT |
208 | }; |
209 | ||
123d3c13 PM |
210 | static inline int valid_state(suspend_state_t state) |
211 | { | |
a3d25c27 RW |
212 | /* All states need lowlevel support and need to be valid |
213 | * to the lowlevel implementation, no valid callback | |
9684e51c JB |
214 | * implies that none are valid. */ |
215 | if (!pm_ops || !pm_ops->valid || !pm_ops->valid(state)) | |
123d3c13 PM |
216 | return 0; |
217 | return 1; | |
218 | } | |
219 | ||
1da177e4 LT |
220 | |
221 | /** | |
222 | * enter_state - Do common work of entering low-power state. | |
223 | * @state: pm_state structure for state we're entering. | |
224 | * | |
225 | * Make sure we're the only ones trying to enter a sleep state. Fail | |
226 | * if someone has beat us to it, since we don't want anything weird to | |
227 | * happen when we wake up. | |
228 | * Then, do the setup for suspend, enter the state, and cleaup (after | |
229 | * we've woken up). | |
230 | */ | |
1da177e4 LT |
231 | static int enter_state(suspend_state_t state) |
232 | { | |
233 | int error; | |
234 | ||
123d3c13 | 235 | if (!valid_state(state)) |
eb9289eb | 236 | return -ENODEV; |
a6d70980 | 237 | if (!mutex_trylock(&pm_mutex)) |
1da177e4 LT |
238 | return -EBUSY; |
239 | ||
82428b62 | 240 | pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); |
6c961dfb | 241 | if ((error = suspend_prepare())) |
1da177e4 LT |
242 | goto Unlock; |
243 | ||
82428b62 | 244 | pr_debug("PM: Entering %s sleep\n", pm_states[state]); |
6c961dfb | 245 | error = suspend_devices_and_enter(state); |
1da177e4 | 246 | |
82428b62 | 247 | pr_debug("PM: Finishing wakeup.\n"); |
6c961dfb | 248 | suspend_finish(); |
1da177e4 | 249 | Unlock: |
a6d70980 | 250 | mutex_unlock(&pm_mutex); |
1da177e4 LT |
251 | return error; |
252 | } | |
253 | ||
1da177e4 LT |
254 | |
255 | /** | |
256 | * pm_suspend - Externally visible function for suspending system. | |
a3d25c27 | 257 | * @state: Enumerated value of state to enter. |
1da177e4 LT |
258 | * |
259 | * Determine whether or not value is within range, get state | |
260 | * structure, and enter (above). | |
261 | */ | |
262 | ||
263 | int pm_suspend(suspend_state_t state) | |
264 | { | |
e2a5b420 | 265 | if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) |
1da177e4 LT |
266 | return enter_state(state); |
267 | return -EINVAL; | |
268 | } | |
269 | ||
4cf30348 | 270 | EXPORT_SYMBOL(pm_suspend); |
1da177e4 LT |
271 | |
272 | decl_subsys(power,NULL,NULL); | |
273 | ||
274 | ||
275 | /** | |
276 | * state - control system power state. | |
277 | * | |
278 | * show() returns what states are supported, which is hard-coded to | |
279 | * 'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and | |
280 | * 'disk' (Suspend-to-Disk). | |
281 | * | |
282 | * store() accepts one of those strings, translates it into the | |
283 | * proper enumerated value, and initiates a suspend transition. | |
284 | */ | |
285 | ||
823bccfc | 286 | static ssize_t state_show(struct kset *kset, char *buf) |
1da177e4 LT |
287 | { |
288 | int i; | |
289 | char * s = buf; | |
290 | ||
291 | for (i = 0; i < PM_SUSPEND_MAX; i++) { | |
123d3c13 PM |
292 | if (pm_states[i] && valid_state(i)) |
293 | s += sprintf(s,"%s ", pm_states[i]); | |
1da177e4 | 294 | } |
a3d25c27 RW |
295 | #ifdef CONFIG_SOFTWARE_SUSPEND |
296 | s += sprintf(s, "%s\n", "disk"); | |
297 | #else | |
298 | if (s != buf) | |
299 | /* convert the last space to a newline */ | |
300 | *(s-1) = '\n'; | |
301 | #endif | |
1da177e4 LT |
302 | return (s - buf); |
303 | } | |
304 | ||
823bccfc | 305 | static ssize_t state_store(struct kset *kset, const char *buf, size_t n) |
1da177e4 LT |
306 | { |
307 | suspend_state_t state = PM_SUSPEND_STANDBY; | |
3b364b8d | 308 | const char * const *s; |
1da177e4 LT |
309 | char *p; |
310 | int error; | |
311 | int len; | |
312 | ||
313 | p = memchr(buf, '\n', n); | |
314 | len = p ? p - buf : n; | |
315 | ||
a3d25c27 | 316 | /* First, check if we are requested to hibernate */ |
8d98a690 | 317 | if (len == 4 && !strncmp(buf, "disk", len)) { |
a3d25c27 RW |
318 | error = hibernate(); |
319 | return error ? error : n; | |
320 | } | |
321 | ||
1da177e4 | 322 | for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) { |
8d98a690 | 323 | if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) |
1da177e4 LT |
324 | break; |
325 | } | |
47bb7899 | 326 | if (state < PM_SUSPEND_MAX && *s) |
1da177e4 LT |
327 | error = enter_state(state); |
328 | else | |
329 | error = -EINVAL; | |
330 | return error ? error : n; | |
331 | } | |
332 | ||
333 | power_attr(state); | |
334 | ||
c5c6ba4e RW |
335 | #ifdef CONFIG_PM_TRACE |
336 | int pm_trace_enabled; | |
337 | ||
823bccfc | 338 | static ssize_t pm_trace_show(struct kset *kset, char *buf) |
c5c6ba4e RW |
339 | { |
340 | return sprintf(buf, "%d\n", pm_trace_enabled); | |
341 | } | |
342 | ||
343 | static ssize_t | |
823bccfc | 344 | pm_trace_store(struct kset *kset, const char *buf, size_t n) |
c5c6ba4e RW |
345 | { |
346 | int val; | |
347 | ||
348 | if (sscanf(buf, "%d", &val) == 1) { | |
349 | pm_trace_enabled = !!val; | |
350 | return n; | |
351 | } | |
352 | return -EINVAL; | |
353 | } | |
354 | ||
355 | power_attr(pm_trace); | |
356 | ||
357 | static struct attribute * g[] = { | |
358 | &state_attr.attr, | |
359 | &pm_trace_attr.attr, | |
360 | NULL, | |
361 | }; | |
362 | #else | |
1da177e4 LT |
363 | static struct attribute * g[] = { |
364 | &state_attr.attr, | |
365 | NULL, | |
366 | }; | |
c5c6ba4e | 367 | #endif /* CONFIG_PM_TRACE */ |
1da177e4 LT |
368 | |
369 | static struct attribute_group attr_group = { | |
370 | .attrs = g, | |
371 | }; | |
372 | ||
373 | ||
374 | static int __init pm_init(void) | |
375 | { | |
376 | int error = subsystem_register(&power_subsys); | |
377 | if (!error) | |
823bccfc | 378 | error = sysfs_create_group(&power_subsys.kobj,&attr_group); |
1da177e4 LT |
379 | return error; |
380 | } | |
381 | ||
382 | core_initcall(pm_init); |