PM: Rename device_power_down/up()
[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/kmod.h>
18 #include <linux/init.h>
19 #include <linux/console.h>
20 #include <linux/cpu.h>
21 #include <linux/resume-trace.h>
22 #include <linux/freezer.h>
23 #include <linux/vmstat.h>
24 #include <linux/syscalls.h>
25
26 #include "power.h"
27
28 DEFINE_MUTEX(pm_mutex);
29
30 unsigned int pm_flags;
31 EXPORT_SYMBOL(pm_flags);
32
33 #ifdef CONFIG_PM_SLEEP
34
35 /* Routines for PM-transition notifications */
36
37 static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
38
39 int register_pm_notifier(struct notifier_block *nb)
40 {
41         return blocking_notifier_chain_register(&pm_chain_head, nb);
42 }
43 EXPORT_SYMBOL_GPL(register_pm_notifier);
44
45 int unregister_pm_notifier(struct notifier_block *nb)
46 {
47         return blocking_notifier_chain_unregister(&pm_chain_head, nb);
48 }
49 EXPORT_SYMBOL_GPL(unregister_pm_notifier);
50
51 int pm_notifier_call_chain(unsigned long val)
52 {
53         return (blocking_notifier_call_chain(&pm_chain_head, val, NULL)
54                         == NOTIFY_BAD) ? -EINVAL : 0;
55 }
56
57 #ifdef CONFIG_PM_DEBUG
58 int pm_test_level = TEST_NONE;
59
60 static const char * const pm_tests[__TEST_AFTER_LAST] = {
61         [TEST_NONE] = "none",
62         [TEST_CORE] = "core",
63         [TEST_CPUS] = "processors",
64         [TEST_PLATFORM] = "platform",
65         [TEST_DEVICES] = "devices",
66         [TEST_FREEZER] = "freezer",
67 };
68
69 static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
70                                 char *buf)
71 {
72         char *s = buf;
73         int level;
74
75         for (level = TEST_FIRST; level <= TEST_MAX; level++)
76                 if (pm_tests[level]) {
77                         if (level == pm_test_level)
78                                 s += sprintf(s, "[%s] ", pm_tests[level]);
79                         else
80                                 s += sprintf(s, "%s ", pm_tests[level]);
81                 }
82
83         if (s != buf)
84                 /* convert the last space to a newline */
85                 *(s-1) = '\n';
86
87         return (s - buf);
88 }
89
90 static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
91                                 const char *buf, size_t n)
92 {
93         const char * const *s;
94         int level;
95         char *p;
96         int len;
97         int error = -EINVAL;
98
99         p = memchr(buf, '\n', n);
100         len = p ? p - buf : n;
101
102         mutex_lock(&pm_mutex);
103
104         level = TEST_FIRST;
105         for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
106                 if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
107                         pm_test_level = level;
108                         error = 0;
109                         break;
110                 }
111
112         mutex_unlock(&pm_mutex);
113
114         return error ? error : n;
115 }
116
117 power_attr(pm_test);
118 #endif /* CONFIG_PM_DEBUG */
119
120 #endif /* CONFIG_PM_SLEEP */
121
122 #ifdef CONFIG_SUSPEND
123
124 static int suspend_test(int level)
125 {
126 #ifdef CONFIG_PM_DEBUG
127         if (pm_test_level == level) {
128                 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
129                 mdelay(5000);
130                 return 1;
131         }
132 #endif /* !CONFIG_PM_DEBUG */
133         return 0;
134 }
135
136 #ifdef CONFIG_PM_TEST_SUSPEND
137
138 /*
139  * We test the system suspend code by setting an RTC wakealarm a short
140  * time in the future, then suspending.  Suspending the devices won't
141  * normally take long ... some systems only need a few milliseconds.
142  *
143  * The time it takes is system-specific though, so when we test this
144  * during system bootup we allow a LOT of time.
145  */
146 #define TEST_SUSPEND_SECONDS    5
147
148 static unsigned long suspend_test_start_time;
149
150 static void suspend_test_start(void)
151 {
152         /* FIXME Use better timebase than "jiffies", ideally a clocksource.
153          * What we want is a hardware counter that will work correctly even
154          * during the irqs-are-off stages of the suspend/resume cycle...
155          */
156         suspend_test_start_time = jiffies;
157 }
158
159 static void suspend_test_finish(const char *label)
160 {
161         long nj = jiffies - suspend_test_start_time;
162         unsigned msec;
163
164         msec = jiffies_to_msecs(abs(nj));
165         pr_info("PM: %s took %d.%03d seconds\n", label,
166                         msec / 1000, msec % 1000);
167
168         /* Warning on suspend means the RTC alarm period needs to be
169          * larger -- the system was sooo slooowwww to suspend that the
170          * alarm (should have) fired before the system went to sleep!
171          *
172          * Warning on either suspend or resume also means the system
173          * has some performance issues.  The stack dump of a WARN_ON
174          * is more likely to get the right attention than a printk...
175          */
176         WARN(msec > (TEST_SUSPEND_SECONDS * 1000), "Component: %s\n", label);
177 }
178
179 #else
180
181 static void suspend_test_start(void)
182 {
183 }
184
185 static void suspend_test_finish(const char *label)
186 {
187 }
188
189 #endif
190
191 /* This is just an arbitrary number */
192 #define FREE_PAGE_NUMBER (100)
193
194 static struct platform_suspend_ops *suspend_ops;
195
196 /**
197  *      suspend_set_ops - Set the global suspend method table.
198  *      @ops:   Pointer to ops structure.
199  */
200
201 void suspend_set_ops(struct platform_suspend_ops *ops)
202 {
203         mutex_lock(&pm_mutex);
204         suspend_ops = ops;
205         mutex_unlock(&pm_mutex);
206 }
207
208 /**
209  * suspend_valid_only_mem - generic memory-only valid callback
210  *
211  * Platform drivers that implement mem suspend only and only need
212  * to check for that in their .valid callback can use this instead
213  * of rolling their own .valid callback.
214  */
215 int suspend_valid_only_mem(suspend_state_t state)
216 {
217         return state == PM_SUSPEND_MEM;
218 }
219
220 /**
221  *      suspend_prepare - Do prep work before entering low-power state.
222  *
223  *      This is common code that is called for each state that we're entering.
224  *      Run suspend notifiers, allocate a console and stop all processes.
225  */
226 static int suspend_prepare(void)
227 {
228         int error;
229         unsigned int free_pages;
230
231         if (!suspend_ops || !suspend_ops->enter)
232                 return -EPERM;
233
234         pm_prepare_console();
235
236         error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
237         if (error)
238                 goto Finish;
239
240         error = usermodehelper_disable();
241         if (error)
242                 goto Finish;
243
244         if (suspend_freeze_processes()) {
245                 error = -EAGAIN;
246                 goto Thaw;
247         }
248
249         free_pages = global_page_state(NR_FREE_PAGES);
250         if (free_pages < FREE_PAGE_NUMBER) {
251                 pr_debug("PM: free some memory\n");
252                 shrink_all_memory(FREE_PAGE_NUMBER - free_pages);
253                 if (nr_free_pages() < FREE_PAGE_NUMBER) {
254                         error = -ENOMEM;
255                         printk(KERN_ERR "PM: No enough memory\n");
256                 }
257         }
258         if (!error)
259                 return 0;
260
261  Thaw:
262         suspend_thaw_processes();
263         usermodehelper_enable();
264  Finish:
265         pm_notifier_call_chain(PM_POST_SUSPEND);
266         pm_restore_console();
267         return error;
268 }
269
270 /* default implementation */
271 void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
272 {
273         local_irq_disable();
274 }
275
276 /* default implementation */
277 void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
278 {
279         local_irq_enable();
280 }
281
282 /**
283  *      suspend_enter - enter the desired system sleep state.
284  *      @state:         state to enter
285  *
286  *      This function should be called after devices have been suspended.
287  */
288 static int suspend_enter(suspend_state_t state)
289 {
290         int error;
291
292         if (suspend_ops->prepare) {
293                 error = suspend_ops->prepare();
294                 if (error)
295                         return error;
296         }
297
298         error = device_suspend_noirq(PMSG_SUSPEND);
299         if (error) {
300                 printk(KERN_ERR "PM: Some devices failed to power down\n");
301                 goto Platfrom_finish;
302         }
303
304         if (suspend_ops->prepare_late) {
305                 error = suspend_ops->prepare_late();
306                 if (error)
307                         goto Power_up_devices;
308         }
309
310         if (suspend_test(TEST_PLATFORM))
311                 goto Platform_wake;
312
313         error = disable_nonboot_cpus();
314         if (error || suspend_test(TEST_CPUS))
315                 goto Enable_cpus;
316
317         arch_suspend_disable_irqs();
318         BUG_ON(!irqs_disabled());
319
320         error = sysdev_suspend(PMSG_SUSPEND);
321         if (!error) {
322                 if (!suspend_test(TEST_CORE))
323                         error = suspend_ops->enter(state);
324                 sysdev_resume();
325         }
326
327         arch_suspend_enable_irqs();
328         BUG_ON(irqs_disabled());
329
330  Enable_cpus:
331         enable_nonboot_cpus();
332
333  Platform_wake:
334         if (suspend_ops->wake)
335                 suspend_ops->wake();
336
337  Power_up_devices:
338         device_resume_noirq(PMSG_RESUME);
339
340  Platfrom_finish:
341         if (suspend_ops->finish)
342                 suspend_ops->finish();
343
344         return error;
345 }
346
347 /**
348  *      suspend_devices_and_enter - suspend devices and enter the desired system
349  *                                  sleep state.
350  *      @state:           state to enter
351  */
352 int suspend_devices_and_enter(suspend_state_t state)
353 {
354         int error;
355
356         if (!suspend_ops)
357                 return -ENOSYS;
358
359         if (suspend_ops->begin) {
360                 error = suspend_ops->begin(state);
361                 if (error)
362                         goto Close;
363         }
364         suspend_console();
365         suspend_test_start();
366         error = device_suspend(PMSG_SUSPEND);
367         if (error) {
368                 printk(KERN_ERR "PM: Some devices failed to suspend\n");
369                 goto Recover_platform;
370         }
371         suspend_test_finish("suspend devices");
372         if (suspend_test(TEST_DEVICES))
373                 goto Recover_platform;
374
375         suspend_enter(state);
376
377  Resume_devices:
378         suspend_test_start();
379         device_resume(PMSG_RESUME);
380         suspend_test_finish("resume devices");
381         resume_console();
382  Close:
383         if (suspend_ops->end)
384                 suspend_ops->end();
385         return error;
386
387  Recover_platform:
388         if (suspend_ops->recover)
389                 suspend_ops->recover();
390         goto Resume_devices;
391 }
392
393 /**
394  *      suspend_finish - Do final work before exiting suspend sequence.
395  *
396  *      Call platform code to clean up, restart processes, and free the 
397  *      console that we've allocated. This is not called for suspend-to-disk.
398  */
399 static void suspend_finish(void)
400 {
401         suspend_thaw_processes();
402         usermodehelper_enable();
403         pm_notifier_call_chain(PM_POST_SUSPEND);
404         pm_restore_console();
405 }
406
407
408
409
410 static const char * const pm_states[PM_SUSPEND_MAX] = {
411         [PM_SUSPEND_STANDBY]    = "standby",
412         [PM_SUSPEND_MEM]        = "mem",
413 };
414
415 static inline int valid_state(suspend_state_t state)
416 {
417         /* All states need lowlevel support and need to be valid
418          * to the lowlevel implementation, no valid callback
419          * implies that none are valid. */
420         if (!suspend_ops || !suspend_ops->valid || !suspend_ops->valid(state))
421                 return 0;
422         return 1;
423 }
424
425
426 /**
427  *      enter_state - Do common work of entering low-power state.
428  *      @state:         pm_state structure for state we're entering.
429  *
430  *      Make sure we're the only ones trying to enter a sleep state. Fail
431  *      if someone has beat us to it, since we don't want anything weird to
432  *      happen when we wake up.
433  *      Then, do the setup for suspend, enter the state, and cleaup (after
434  *      we've woken up).
435  */
436 static int enter_state(suspend_state_t state)
437 {
438         int error;
439
440         if (!valid_state(state))
441                 return -ENODEV;
442
443         if (!mutex_trylock(&pm_mutex))
444                 return -EBUSY;
445
446         printk(KERN_INFO "PM: Syncing filesystems ... ");
447         sys_sync();
448         printk("done.\n");
449
450         pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
451         error = suspend_prepare();
452         if (error)
453                 goto Unlock;
454
455         if (suspend_test(TEST_FREEZER))
456                 goto Finish;
457
458         pr_debug("PM: Entering %s sleep\n", pm_states[state]);
459         error = suspend_devices_and_enter(state);
460
461  Finish:
462         pr_debug("PM: Finishing wakeup.\n");
463         suspend_finish();
464  Unlock:
465         mutex_unlock(&pm_mutex);
466         return error;
467 }
468
469
470 /**
471  *      pm_suspend - Externally visible function for suspending system.
472  *      @state:         Enumerated value of state to enter.
473  *
474  *      Determine whether or not value is within range, get state 
475  *      structure, and enter (above).
476  */
477
478 int pm_suspend(suspend_state_t state)
479 {
480         if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
481                 return enter_state(state);
482         return -EINVAL;
483 }
484
485 EXPORT_SYMBOL(pm_suspend);
486
487 #endif /* CONFIG_SUSPEND */
488
489 struct kobject *power_kobj;
490
491 /**
492  *      state - control system power state.
493  *
494  *      show() returns what states are supported, which is hard-coded to
495  *      'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and
496  *      'disk' (Suspend-to-Disk).
497  *
498  *      store() accepts one of those strings, translates it into the 
499  *      proper enumerated value, and initiates a suspend transition.
500  */
501
502 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
503                           char *buf)
504 {
505         char *s = buf;
506 #ifdef CONFIG_SUSPEND
507         int i;
508
509         for (i = 0; i < PM_SUSPEND_MAX; i++) {
510                 if (pm_states[i] && valid_state(i))
511                         s += sprintf(s,"%s ", pm_states[i]);
512         }
513 #endif
514 #ifdef CONFIG_HIBERNATION
515         s += sprintf(s, "%s\n", "disk");
516 #else
517         if (s != buf)
518                 /* convert the last space to a newline */
519                 *(s-1) = '\n';
520 #endif
521         return (s - buf);
522 }
523
524 static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
525                            const char *buf, size_t n)
526 {
527 #ifdef CONFIG_SUSPEND
528         suspend_state_t state = PM_SUSPEND_STANDBY;
529         const char * const *s;
530 #endif
531         char *p;
532         int len;
533         int error = -EINVAL;
534
535         p = memchr(buf, '\n', n);
536         len = p ? p - buf : n;
537
538         /* First, check if we are requested to hibernate */
539         if (len == 4 && !strncmp(buf, "disk", len)) {
540                 error = hibernate();
541   goto Exit;
542         }
543
544 #ifdef CONFIG_SUSPEND
545         for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
546                 if (*s && len == strlen(*s) && !strncmp(buf, *s, len))
547                         break;
548         }
549         if (state < PM_SUSPEND_MAX && *s)
550                 error = enter_state(state);
551 #endif
552
553  Exit:
554         return error ? error : n;
555 }
556
557 power_attr(state);
558
559 #ifdef CONFIG_PM_TRACE
560 int pm_trace_enabled;
561
562 static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
563                              char *buf)
564 {
565         return sprintf(buf, "%d\n", pm_trace_enabled);
566 }
567
568 static ssize_t
569 pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
570                const char *buf, size_t n)
571 {
572         int val;
573
574         if (sscanf(buf, "%d", &val) == 1) {
575                 pm_trace_enabled = !!val;
576                 return n;
577         }
578         return -EINVAL;
579 }
580
581 power_attr(pm_trace);
582 #endif /* CONFIG_PM_TRACE */
583
584 static struct attribute * g[] = {
585         &state_attr.attr,
586 #ifdef CONFIG_PM_TRACE
587         &pm_trace_attr.attr,
588 #endif
589 #if defined(CONFIG_PM_SLEEP) && defined(CONFIG_PM_DEBUG)
590         &pm_test_attr.attr,
591 #endif
592         NULL,
593 };
594
595 static struct attribute_group attr_group = {
596         .attrs = g,
597 };
598
599
600 static int __init pm_init(void)
601 {
602         power_kobj = kobject_create_and_add("power", NULL);
603         if (!power_kobj)
604                 return -ENOMEM;
605         return sysfs_create_group(power_kobj, &attr_group);
606 }
607
608 core_initcall(pm_init);
609
610
611 #ifdef CONFIG_PM_TEST_SUSPEND
612
613 #include <linux/rtc.h>
614
615 /*
616  * To test system suspend, we need a hands-off mechanism to resume the
617  * system.  RTCs wake alarms are a common self-contained mechanism.
618  */
619
620 static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state)
621 {
622         static char err_readtime[] __initdata =
623                 KERN_ERR "PM: can't read %s time, err %d\n";
624         static char err_wakealarm [] __initdata =
625                 KERN_ERR "PM: can't set %s wakealarm, err %d\n";
626         static char err_suspend[] __initdata =
627                 KERN_ERR "PM: suspend test failed, error %d\n";
628         static char info_test[] __initdata =
629                 KERN_INFO "PM: test RTC wakeup from '%s' suspend\n";
630
631         unsigned long           now;
632         struct rtc_wkalrm       alm;
633         int                     status;
634
635         /* this may fail if the RTC hasn't been initialized */
636         status = rtc_read_time(rtc, &alm.time);
637         if (status < 0) {
638                 printk(err_readtime, dev_name(&rtc->dev), status);
639                 return;
640         }
641         rtc_tm_to_time(&alm.time, &now);
642
643         memset(&alm, 0, sizeof alm);
644         rtc_time_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time);
645         alm.enabled = true;
646
647         status = rtc_set_alarm(rtc, &alm);
648         if (status < 0) {
649                 printk(err_wakealarm, dev_name(&rtc->dev), status);
650                 return;
651         }
652
653         if (state == PM_SUSPEND_MEM) {
654                 printk(info_test, pm_states[state]);
655                 status = pm_suspend(state);
656                 if (status == -ENODEV)
657                         state = PM_SUSPEND_STANDBY;
658         }
659         if (state == PM_SUSPEND_STANDBY) {
660                 printk(info_test, pm_states[state]);
661                 status = pm_suspend(state);
662         }
663         if (status < 0)
664                 printk(err_suspend, status);
665
666         /* Some platforms can't detect that the alarm triggered the
667          * wakeup, or (accordingly) disable it after it afterwards.
668          * It's supposed to give oneshot behavior; cope.
669          */
670         alm.enabled = false;
671         rtc_set_alarm(rtc, &alm);
672 }
673
674 static int __init has_wakealarm(struct device *dev, void *name_ptr)
675 {
676         struct rtc_device *candidate = to_rtc_device(dev);
677
678         if (!candidate->ops->set_alarm)
679                 return 0;
680         if (!device_may_wakeup(candidate->dev.parent))
681                 return 0;
682
683         *(const char **)name_ptr = dev_name(dev);
684         return 1;
685 }
686
687 /*
688  * Kernel options like "test_suspend=mem" force suspend/resume sanity tests
689  * at startup time.  They're normally disabled, for faster boot and because
690  * we can't know which states really work on this particular system.
691  */
692 static suspend_state_t test_state __initdata = PM_SUSPEND_ON;
693
694 static char warn_bad_state[] __initdata =
695         KERN_WARNING "PM: can't test '%s' suspend state\n";
696
697 static int __init setup_test_suspend(char *value)
698 {
699         unsigned i;
700
701         /* "=mem" ==> "mem" */
702         value++;
703         for (i = 0; i < PM_SUSPEND_MAX; i++) {
704                 if (!pm_states[i])
705                         continue;
706                 if (strcmp(pm_states[i], value) != 0)
707                         continue;
708                 test_state = (__force suspend_state_t) i;
709                 return 0;
710         }
711         printk(warn_bad_state, value);
712         return 0;
713 }
714 __setup("test_suspend", setup_test_suspend);
715
716 static int __init test_suspend(void)
717 {
718         static char             warn_no_rtc[] __initdata =
719                 KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n";
720
721         char                    *pony = NULL;
722         struct rtc_device       *rtc = NULL;
723
724         /* PM is initialized by now; is that state testable? */
725         if (test_state == PM_SUSPEND_ON)
726                 goto done;
727         if (!valid_state(test_state)) {
728                 printk(warn_bad_state, pm_states[test_state]);
729                 goto done;
730         }
731
732         /* RTCs have initialized by now too ... can we use one? */
733         class_find_device(rtc_class, NULL, &pony, has_wakealarm);
734         if (pony)
735                 rtc = rtc_class_open(pony);
736         if (!rtc) {
737                 printk(warn_no_rtc);
738                 goto done;
739         }
740
741         /* go for it */
742         test_wakealarm(rtc, test_state);
743         rtc_class_close(rtc);
744 done:
745         return 0;
746 }
747 late_initcall(test_suspend);
748
749 #endif /* CONFIG_PM_TEST_SUSPEND */