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