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
11 #include <linux/module.h>
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>
18 #include <linux/console.h>
19 #include <linux/cpu.h>
20 #include <linux/resume-trace.h>
21 #include <linux/freezer.h>
22 #include <linux/vmstat.h>
23 #include <linux/syscalls.h>
24
25 #include "power.h"
26
27 DEFINE_MUTEX(pm_mutex);
28
29 unsigned int pm_flags;
30 EXPORT_SYMBOL(pm_flags);
31
32 #ifdef CONFIG_PM_SLEEP
33
34 /* Routines for PM-transition notifications */
35
36 static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
37
38 int register_pm_notifier(struct notifier_block *nb)
39 {
40 return blocking_notifier_chain_register(&pm_chain_head, nb);
41 }
42 EXPORT_SYMBOL_GPL(register_pm_notifier);
43
44 int unregister_pm_notifier(struct notifier_block *nb)
45 {
46 return blocking_notifier_chain_unregister(&pm_chain_head, nb);
47 }
48 EXPORT_SYMBOL_GPL(unregister_pm_notifier);
49
50 int pm_notifier_call_chain(unsigned long val)
51 {
52 return (blocking_notifier_call_chain(&pm_chain_head, val, NULL)
53 == NOTIFY_BAD) ? -EINVAL : 0;
54 }
55
56 #ifdef CONFIG_PM_DEBUG
57 int pm_test_level = TEST_NONE;
58
59 static int suspend_test(int level)
60 {
61 if (pm_test_level == level) {
62 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
63 mdelay(5000);
64 return 1;
65 }
66 return 0;
67 }
68
69 static const char * const pm_tests[__TEST_AFTER_LAST] = {
70 [TEST_NONE] = "none",
71 [TEST_CORE] = "core",
72 [TEST_CPUS] = "processors",
73 [TEST_PLATFORM] = "platform",
74 [TEST_DEVICES] = "devices",
75 [TEST_FREEZER] = "freezer",
76 };
77
78 static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
79 char *buf)
80 {
81 char *s = buf;
82 int level;
83
84 for (level = TEST_FIRST; level <= TEST_MAX; level++)
85 if (pm_tests[level]) {
86 if (level == pm_test_level)
87 s += sprintf(s, "[%s] ", pm_tests[level]);
88 else
89 s += sprintf(s, "%s ", pm_tests[level]);
90 }
91
92 if (s != buf)
93 /* convert the last space to a newline */
94 *(s-1) = '\n';
95
96 return (s - buf);
97 }
98
99 static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
100 const char *buf, size_t n)
101 {
102 const char * const *s;
103 int level;
104 char *p;
105 int len;
106 int error = -EINVAL;
107
108 p = memchr(buf, '\n', n);
109 len = p ? p - buf : n;
110
111 mutex_lock(&pm_mutex);
112
113 level = TEST_FIRST;
114 for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
115 if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
116 pm_test_level = level;
117 error = 0;
118 break;
119 }
120
121 mutex_unlock(&pm_mutex);
122
123 return error ? error : n;
124 }
125
126 power_attr(pm_test);
127 #else /* !CONFIG_PM_DEBUG */
128 static inline int suspend_test(int level) { return 0; }
129 #endif /* !CONFIG_PM_DEBUG */
130
131 #endif /* CONFIG_PM_SLEEP */
132
133 #ifdef CONFIG_SUSPEND
134
135 /* This is just an arbitrary number */
136 #define FREE_PAGE_NUMBER (100)
137
138 static struct platform_suspend_ops *suspend_ops;
139
140 /**
141 * suspend_set_ops - Set the global suspend method table.
142 * @ops: Pointer to ops structure.
143 */
144
145 void suspend_set_ops(struct platform_suspend_ops *ops)
146 {
147 mutex_lock(&pm_mutex);
148 suspend_ops = ops;
149 mutex_unlock(&pm_mutex);
150 }
151
152 /**
153 * suspend_valid_only_mem - generic memory-only valid callback
154 *
155 * Platform drivers that implement mem suspend only and only need
156 * to check for that in their .valid callback can use this instead
157 * of rolling their own .valid callback.
158 */
159 int suspend_valid_only_mem(suspend_state_t state)
160 {
161 return state == PM_SUSPEND_MEM;
162 }
163
164 /**
165 * suspend_prepare - Do prep work before entering low-power state.
166 *
167 * This is common code that is called for each state that we're entering.
168 * Run suspend notifiers, allocate a console and stop all processes.
169 */
170 static int suspend_prepare(void)
171 {
172 int error;
173 unsigned int free_pages;
174
175 if (!suspend_ops || !suspend_ops->enter)
176 return -EPERM;
177
178 pm_prepare_console();
179
180 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
181 if (error)
182 goto Finish;
183
184 if (suspend_freeze_processes()) {
185 error = -EAGAIN;
186 goto Thaw;
187 }
188
189 free_pages = global_page_state(NR_FREE_PAGES);
190 if (free_pages < FREE_PAGE_NUMBER) {
191 pr_debug("PM: free some memory\n");
192 shrink_all_memory(FREE_PAGE_NUMBER - free_pages);
193 if (nr_free_pages() < FREE_PAGE_NUMBER) {
194 error = -ENOMEM;
195 printk(KERN_ERR "PM: No enough memory\n");
196 }
197 }
198 if (!error)
199 return 0;
200
201 Thaw:
202 suspend_thaw_processes();
203 Finish:
204 pm_notifier_call_chain(PM_POST_SUSPEND);
205 pm_restore_console();
206 return error;
207 }
208
209 /* default implementation */
210 void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
211 {
212 local_irq_disable();
213 }
214
215 /* default implementation */
216 void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
217 {
218 local_irq_enable();
219 }
220
221 /**
222 * suspend_enter - enter the desired system sleep state.
223 * @state: state to enter
224 *
225 * This function should be called after devices have been suspended.
226 */
227 static int suspend_enter(suspend_state_t state)
228 {
229 int error = 0;
230
231 arch_suspend_disable_irqs();
232 BUG_ON(!irqs_disabled());
233
234 if ((error = device_power_down(PMSG_SUSPEND))) {
235 printk(KERN_ERR "PM: Some devices failed to power down\n");
236 goto Done;
237 }
238
239 if (!suspend_test(TEST_CORE))
240 error = suspend_ops->enter(state);
241
242 device_power_up();
243 Done:
244 arch_suspend_enable_irqs();
245 BUG_ON(irqs_disabled());
246 return error;
247 }
248
249 /**
250 * suspend_devices_and_enter - suspend devices and enter the desired system
251 * sleep state.
252 * @state: state to enter
253 */
254 int suspend_devices_and_enter(suspend_state_t state)
255 {
256 int error;
257
258 if (!suspend_ops)
259 return -ENOSYS;
260
261 if (suspend_ops->begin) {
262 error = suspend_ops->begin(state);
263 if (error)
264 goto Close;
265 }
266 suspend_console();
267 error = device_suspend(PMSG_SUSPEND);
268 if (error) {
269 printk(KERN_ERR "PM: Some devices failed to suspend\n");
270 goto Resume_console;
271 }
272
273 if (suspend_test(TEST_DEVICES))
274 goto Resume_devices;
275
276 if (suspend_ops->prepare) {
277 error = suspend_ops->prepare();
278 if (error)
279 goto Resume_devices;
280 }
281
282 if (suspend_test(TEST_PLATFORM))
283 goto Finish;
284
285 error = disable_nonboot_cpus();
286 if (!error && !suspend_test(TEST_CPUS))
287 suspend_enter(state);
288
289 enable_nonboot_cpus();
290 Finish:
291 if (suspend_ops->finish)
292 suspend_ops->finish();
293 Resume_devices:
294 device_resume();
295 Resume_console:
296 resume_console();
297 Close:
298 if (suspend_ops->end)
299 suspend_ops->end();
300 return error;
301 }
302
303 /**
304 * suspend_finish - Do final work before exiting suspend sequence.
305 *
306 * Call platform code to clean up, restart processes, and free the
307 * console that we've allocated. This is not called for suspend-to-disk.
308 */
309 static void suspend_finish(void)
310 {
311 suspend_thaw_processes();
312 pm_notifier_call_chain(PM_POST_SUSPEND);
313 pm_restore_console();
314 }
315
316
317
318
319 static const char * const pm_states[PM_SUSPEND_MAX] = {
320 [PM_SUSPEND_STANDBY] = "standby",
321 [PM_SUSPEND_MEM] = "mem",
322 };
323
324 static inline int valid_state(suspend_state_t state)
325 {
326 /* All states need lowlevel support and need to be valid
327 * to the lowlevel implementation, no valid callback
328 * implies that none are valid. */
329 if (!suspend_ops || !suspend_ops->valid || !suspend_ops->valid(state))
330 return 0;
331 return 1;
332 }
333
334
335 /**
336 * enter_state - Do common work of entering low-power state.
337 * @state: pm_state structure for state we're entering.
338 *
339 * Make sure we're the only ones trying to enter a sleep state. Fail
340 * if someone has beat us to it, since we don't want anything weird to
341 * happen when we wake up.
342 * Then, do the setup for suspend, enter the state, and cleaup (after
343 * we've woken up).
344 */
345 static int enter_state(suspend_state_t state)
346 {
347 int error;
348
349 if (!valid_state(state))
350 return -ENODEV;
351
352 if (!mutex_trylock(&pm_mutex))
353 return -EBUSY;
354
355 printk(KERN_INFO "PM: Syncing filesystems ... ");
356 sys_sync();
357 printk("done.\n");
358
359 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
360 error = suspend_prepare();
361 if (error)
362 goto Unlock;
363
364 if (suspend_test(TEST_FREEZER))
365 goto Finish;
366
367 pr_debug("PM: Entering %s sleep\n", pm_states[state]);
368 error = suspend_devices_and_enter(state);
369
370 Finish:
371 pr_debug("PM: Finishing wakeup.\n");
372 suspend_finish();
373 Unlock:
374 mutex_unlock(&pm_mutex);
375 return error;
376 }
377
378
379 /**
380 * pm_suspend - Externally visible function for suspending system.
381 * @state: Enumerated value of state to enter.
382 *
383 * Determine whether or not value is within range, get state
384 * structure, and enter (above).
385 */
386
387 int pm_suspend(suspend_state_t state)
388 {
389 if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
390 return enter_state(state);
391 return -EINVAL;
392 }
393
394 EXPORT_SYMBOL(pm_suspend);
395
396 #endif /* CONFIG_SUSPEND */
397
398 struct kobject *power_kobj;
399
400 /**
401 * state - control system power state.
402 *
403 * show() returns what states are supported, which is hard-coded to
404 * 'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and
405 * 'disk' (Suspend-to-Disk).
406 *
407 * store() accepts one of those strings, translates it into the
408 * proper enumerated value, and initiates a suspend transition.
409 */
410
411 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
412 char *buf)
413 {
414 char *s = buf;
415 #ifdef CONFIG_SUSPEND
416 int i;
417
418 for (i = 0; i < PM_SUSPEND_MAX; i++) {
419 if (pm_states[i] && valid_state(i))
420 s += sprintf(s,"%s ", pm_states[i]);
421 }
422 #endif
423 #ifdef CONFIG_HIBERNATION
424 s += sprintf(s, "%s\n", "disk");
425 #else
426 if (s != buf)
427 /* convert the last space to a newline */
428 *(s-1) = '\n';
429 #endif
430 return (s - buf);
431 }
432
433 static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
434 const char *buf, size_t n)
435 {
436 #ifdef CONFIG_SUSPEND
437 suspend_state_t state = PM_SUSPEND_STANDBY;
438 const char * const *s;
439 #endif
440 char *p;
441 int len;
442 int error = -EINVAL;
443
444 p = memchr(buf, '\n', n);
445 len = p ? p - buf : n;
446
447 /* First, check if we are requested to hibernate */
448 if (len == 4 && !strncmp(buf, "disk", len)) {
449 error = hibernate();
450 goto Exit;
451 }
452
453 #ifdef CONFIG_SUSPEND
454 for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
455 if (*s && len == strlen(*s) && !strncmp(buf, *s, len))
456 break;
457 }
458 if (state < PM_SUSPEND_MAX && *s)
459 error = enter_state(state);
460 #endif
461
462 Exit:
463 return error ? error : n;
464 }
465
466 power_attr(state);
467
468 #ifdef CONFIG_PM_TRACE
469 int pm_trace_enabled;
470
471 static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
472 char *buf)
473 {
474 return sprintf(buf, "%d\n", pm_trace_enabled);
475 }
476
477 static ssize_t
478 pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
479 const char *buf, size_t n)
480 {
481 int val;
482
483 if (sscanf(buf, "%d", &val) == 1) {
484 pm_trace_enabled = !!val;
485 return n;
486 }
487 return -EINVAL;
488 }
489
490 power_attr(pm_trace);
491 #endif /* CONFIG_PM_TRACE */
492
493 static struct attribute * g[] = {
494 &state_attr.attr,
495 #ifdef CONFIG_PM_TRACE
496 &pm_trace_attr.attr,
497 #endif
498 #if defined(CONFIG_PM_SLEEP) && defined(CONFIG_PM_DEBUG)
499 &pm_test_attr.attr,
500 #endif
501 NULL,
502 };
503
504 static struct attribute_group attr_group = {
505 .attrs = g,
506 };
507
508
509 static int __init pm_init(void)
510 {
511 power_kobj = kobject_create_and_add("power", NULL);
512 if (!power_kobj)
513 return -ENOMEM;
514 return sysfs_create_group(power_kobj, &attr_group);
515 }
516
517 core_initcall(pm_init);
518
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