Suspend-related patches for 2.6.27
[linux-2.6.git] / kernel / power / main.c
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         device_pm_lock();
232         arch_suspend_disable_irqs();
233         BUG_ON(!irqs_disabled());
234
235         if ((error = device_power_down(PMSG_SUSPEND))) {
236                 printk(KERN_ERR "PM: Some devices failed to power down\n");
237                 goto Done;
238         }
239
240         if (!suspend_test(TEST_CORE))
241                 error = suspend_ops->enter(state);
242
243         device_power_up(PMSG_RESUME);
244  Done:
245         arch_suspend_enable_irqs();
246         BUG_ON(irqs_disabled());
247         device_pm_unlock();
248         return error;
249 }
250
251 /**
252  *      suspend_devices_and_enter - suspend devices and enter the desired system
253  *                                  sleep state.
254  *      @state:           state to enter
255  */
256 int suspend_devices_and_enter(suspend_state_t state)
257 {
258         int error;
259
260         if (!suspend_ops)
261                 return -ENOSYS;
262
263         if (suspend_ops->begin) {
264                 error = suspend_ops->begin(state);
265                 if (error)
266                         goto Close;
267         }
268         suspend_console();
269         error = device_suspend(PMSG_SUSPEND);
270         if (error) {
271                 printk(KERN_ERR "PM: Some devices failed to suspend\n");
272                 goto Recover_platform;
273         }
274
275         if (suspend_test(TEST_DEVICES))
276                 goto Recover_platform;
277
278         if (suspend_ops->prepare) {
279                 error = suspend_ops->prepare();
280                 if (error)
281                         goto Resume_devices;
282         }
283
284         if (suspend_test(TEST_PLATFORM))
285                 goto Finish;
286
287         error = disable_nonboot_cpus();
288         if (!error && !suspend_test(TEST_CPUS))
289                 suspend_enter(state);
290
291         enable_nonboot_cpus();
292  Finish:
293         if (suspend_ops->finish)
294                 suspend_ops->finish();
295  Resume_devices:
296         device_resume(PMSG_RESUME);
297         resume_console();
298  Close:
299         if (suspend_ops->end)
300                 suspend_ops->end();
301         return error;
302
303  Recover_platform:
304         if (suspend_ops->recover)
305                 suspend_ops->recover();
306         goto Resume_devices;
307 }
308
309 /**
310  *      suspend_finish - Do final work before exiting suspend sequence.
311  *
312  *      Call platform code to clean up, restart processes, and free the 
313  *      console that we've allocated. This is not called for suspend-to-disk.
314  */
315 static void suspend_finish(void)
316 {
317         suspend_thaw_processes();
318         pm_notifier_call_chain(PM_POST_SUSPEND);
319         pm_restore_console();
320 }
321
322
323
324
325 static const char * const pm_states[PM_SUSPEND_MAX] = {
326         [PM_SUSPEND_STANDBY]    = "standby",
327         [PM_SUSPEND_MEM]        = "mem",
328 };
329
330 static inline int valid_state(suspend_state_t state)
331 {
332         /* All states need lowlevel support and need to be valid
333          * to the lowlevel implementation, no valid callback
334          * implies that none are valid. */
335         if (!suspend_ops || !suspend_ops->valid || !suspend_ops->valid(state))
336                 return 0;
337         return 1;
338 }
339
340
341 /**
342  *      enter_state - Do common work of entering low-power state.
343  *      @state:         pm_state structure for state we're entering.
344  *
345  *      Make sure we're the only ones trying to enter a sleep state. Fail
346  *      if someone has beat us to it, since we don't want anything weird to
347  *      happen when we wake up.
348  *      Then, do the setup for suspend, enter the state, and cleaup (after
349  *      we've woken up).
350  */
351 static int enter_state(suspend_state_t state)
352 {
353         int error;
354
355         if (!valid_state(state))
356                 return -ENODEV;
357
358         if (!mutex_trylock(&pm_mutex))
359                 return -EBUSY;
360
361         printk(KERN_INFO "PM: Syncing filesystems ... ");
362         sys_sync();
363         printk("done.\n");
364
365         pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
366         error = suspend_prepare();
367         if (error)
368                 goto Unlock;
369
370         if (suspend_test(TEST_FREEZER))
371                 goto Finish;
372
373         pr_debug("PM: Entering %s sleep\n", pm_states[state]);
374         error = suspend_devices_and_enter(state);
375
376  Finish:
377         pr_debug("PM: Finishing wakeup.\n");
378         suspend_finish();
379  Unlock:
380         mutex_unlock(&pm_mutex);
381         return error;
382 }
383
384
385 /**
386  *      pm_suspend - Externally visible function for suspending system.
387  *      @state:         Enumerated value of state to enter.
388  *
389  *      Determine whether or not value is within range, get state 
390  *      structure, and enter (above).
391  */
392
393 int pm_suspend(suspend_state_t state)
394 {
395         if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
396                 return enter_state(state);
397         return -EINVAL;
398 }
399
400 EXPORT_SYMBOL(pm_suspend);
401
402 #endif /* CONFIG_SUSPEND */
403
404 struct kobject *power_kobj;
405
406 /**
407  *      state - control system power state.
408  *
409  *      show() returns what states are supported, which is hard-coded to
410  *      'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and
411  *      'disk' (Suspend-to-Disk).
412  *
413  *      store() accepts one of those strings, translates it into the 
414  *      proper enumerated value, and initiates a suspend transition.
415  */
416
417 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
418                           char *buf)
419 {
420         char *s = buf;
421 #ifdef CONFIG_SUSPEND
422         int i;
423
424         for (i = 0; i < PM_SUSPEND_MAX; i++) {
425                 if (pm_states[i] && valid_state(i))
426                         s += sprintf(s,"%s ", pm_states[i]);
427         }
428 #endif
429 #ifdef CONFIG_HIBERNATION
430         s += sprintf(s, "%s\n", "disk");
431 #else
432         if (s != buf)
433                 /* convert the last space to a newline */
434                 *(s-1) = '\n';
435 #endif
436         return (s - buf);
437 }
438
439 static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
440                            const char *buf, size_t n)
441 {
442 #ifdef CONFIG_SUSPEND
443         suspend_state_t state = PM_SUSPEND_STANDBY;
444         const char * const *s;
445 #endif
446         char *p;
447         int len;
448         int error = -EINVAL;
449
450         p = memchr(buf, '\n', n);
451         len = p ? p - buf : n;
452
453         /* First, check if we are requested to hibernate */
454         if (len == 4 && !strncmp(buf, "disk", len)) {
455                 error = hibernate();
456   goto Exit;
457         }
458
459 #ifdef CONFIG_SUSPEND
460         for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
461                 if (*s && len == strlen(*s) && !strncmp(buf, *s, len))
462                         break;
463         }
464         if (state < PM_SUSPEND_MAX && *s)
465                 error = enter_state(state);
466 #endif
467
468  Exit:
469         return error ? error : n;
470 }
471
472 power_attr(state);
473
474 #ifdef CONFIG_PM_TRACE
475 int pm_trace_enabled;
476
477 static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
478                              char *buf)
479 {
480         return sprintf(buf, "%d\n", pm_trace_enabled);
481 }
482
483 static ssize_t
484 pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
485                const char *buf, size_t n)
486 {
487         int val;
488
489         if (sscanf(buf, "%d", &val) == 1) {
490                 pm_trace_enabled = !!val;
491                 return n;
492         }
493         return -EINVAL;
494 }
495
496 power_attr(pm_trace);
497 #endif /* CONFIG_PM_TRACE */
498
499 static struct attribute * g[] = {
500         &state_attr.attr,
501 #ifdef CONFIG_PM_TRACE
502         &pm_trace_attr.attr,
503 #endif
504 #if defined(CONFIG_PM_SLEEP) && defined(CONFIG_PM_DEBUG)
505         &pm_test_attr.attr,
506 #endif
507         NULL,
508 };
509
510 static struct attribute_group attr_group = {
511         .attrs = g,
512 };
513
514
515 static int __init pm_init(void)
516 {
517         power_kobj = kobject_create_and_add("power", NULL);
518         if (!power_kobj)
519                 return -ENOMEM;
520         return sysfs_create_group(power_kobj, &attr_group);
521 }
522
523 core_initcall(pm_init);