V4L/DVB (8866): Add dummy FE to the Kconfig-file and fix it
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / power / main.c
blob540b16b68565e74fb9f51f68134f68cc3011b0a0
1 /*
2 * kernel/power/main.c - PM subsystem core functionality.
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 *
7 * This file is released under the GPLv2
9 */
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 #include <linux/ftrace.h>
26 #include "power.h"
28 DEFINE_MUTEX(pm_mutex);
30 unsigned int pm_flags;
31 EXPORT_SYMBOL(pm_flags);
33 #ifdef CONFIG_PM_SLEEP
35 /* Routines for PM-transition notifications */
37 static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
39 int register_pm_notifier(struct notifier_block *nb)
41 return blocking_notifier_chain_register(&pm_chain_head, nb);
43 EXPORT_SYMBOL_GPL(register_pm_notifier);
45 int unregister_pm_notifier(struct notifier_block *nb)
47 return blocking_notifier_chain_unregister(&pm_chain_head, nb);
49 EXPORT_SYMBOL_GPL(unregister_pm_notifier);
51 int pm_notifier_call_chain(unsigned long val)
53 return (blocking_notifier_call_chain(&pm_chain_head, val, NULL)
54 == NOTIFY_BAD) ? -EINVAL : 0;
57 #ifdef CONFIG_PM_DEBUG
58 int pm_test_level = TEST_NONE;
60 static int suspend_test(int level)
62 if (pm_test_level == level) {
63 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
64 mdelay(5000);
65 return 1;
67 return 0;
70 static const char * const pm_tests[__TEST_AFTER_LAST] = {
71 [TEST_NONE] = "none",
72 [TEST_CORE] = "core",
73 [TEST_CPUS] = "processors",
74 [TEST_PLATFORM] = "platform",
75 [TEST_DEVICES] = "devices",
76 [TEST_FREEZER] = "freezer",
79 static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
80 char *buf)
82 char *s = buf;
83 int level;
85 for (level = TEST_FIRST; level <= TEST_MAX; level++)
86 if (pm_tests[level]) {
87 if (level == pm_test_level)
88 s += sprintf(s, "[%s] ", pm_tests[level]);
89 else
90 s += sprintf(s, "%s ", pm_tests[level]);
93 if (s != buf)
94 /* convert the last space to a newline */
95 *(s-1) = '\n';
97 return (s - buf);
100 static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
101 const char *buf, size_t n)
103 const char * const *s;
104 int level;
105 char *p;
106 int len;
107 int error = -EINVAL;
109 p = memchr(buf, '\n', n);
110 len = p ? p - buf : n;
112 mutex_lock(&pm_mutex);
114 level = TEST_FIRST;
115 for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
116 if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
117 pm_test_level = level;
118 error = 0;
119 break;
122 mutex_unlock(&pm_mutex);
124 return error ? error : n;
127 power_attr(pm_test);
128 #else /* !CONFIG_PM_DEBUG */
129 static inline int suspend_test(int level) { return 0; }
130 #endif /* !CONFIG_PM_DEBUG */
132 #endif /* CONFIG_PM_SLEEP */
134 #ifdef CONFIG_SUSPEND
136 #ifdef CONFIG_PM_TEST_SUSPEND
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.
143 * The time it takes is system-specific though, so when we test this
144 * during system bootup we allow a LOT of time.
146 #define TEST_SUSPEND_SECONDS 5
148 static unsigned long suspend_test_start_time;
150 static void suspend_test_start(void)
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...
156 suspend_test_start_time = jiffies;
159 static void suspend_test_finish(const char *label)
161 long nj = jiffies - suspend_test_start_time;
162 unsigned msec;
164 msec = jiffies_to_msecs(abs(nj));
165 pr_info("PM: %s took %d.%03d seconds\n", label,
166 msec / 1000, msec % 1000);
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!
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...
176 WARN_ON(msec > (TEST_SUSPEND_SECONDS * 1000));
179 #else
181 static void suspend_test_start(void)
185 static void suspend_test_finish(const char *label)
189 #endif
191 /* This is just an arbitrary number */
192 #define FREE_PAGE_NUMBER (100)
194 static struct platform_suspend_ops *suspend_ops;
197 * suspend_set_ops - Set the global suspend method table.
198 * @ops: Pointer to ops structure.
201 void suspend_set_ops(struct platform_suspend_ops *ops)
203 mutex_lock(&pm_mutex);
204 suspend_ops = ops;
205 mutex_unlock(&pm_mutex);
209 * suspend_valid_only_mem - generic memory-only valid callback
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.
215 int suspend_valid_only_mem(suspend_state_t state)
217 return state == PM_SUSPEND_MEM;
221 * suspend_prepare - Do prep work before entering low-power state.
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.
226 static int suspend_prepare(void)
228 int error;
229 unsigned int free_pages;
231 if (!suspend_ops || !suspend_ops->enter)
232 return -EPERM;
234 pm_prepare_console();
236 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
237 if (error)
238 goto Finish;
240 if (suspend_freeze_processes()) {
241 error = -EAGAIN;
242 goto Thaw;
245 free_pages = global_page_state(NR_FREE_PAGES);
246 if (free_pages < FREE_PAGE_NUMBER) {
247 pr_debug("PM: free some memory\n");
248 shrink_all_memory(FREE_PAGE_NUMBER - free_pages);
249 if (nr_free_pages() < FREE_PAGE_NUMBER) {
250 error = -ENOMEM;
251 printk(KERN_ERR "PM: No enough memory\n");
254 if (!error)
255 return 0;
257 Thaw:
258 suspend_thaw_processes();
259 Finish:
260 pm_notifier_call_chain(PM_POST_SUSPEND);
261 pm_restore_console();
262 return error;
265 /* default implementation */
266 void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
268 local_irq_disable();
271 /* default implementation */
272 void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
274 local_irq_enable();
278 * suspend_enter - enter the desired system sleep state.
279 * @state: state to enter
281 * This function should be called after devices have been suspended.
283 static int suspend_enter(suspend_state_t state)
285 int error = 0;
287 device_pm_lock();
288 arch_suspend_disable_irqs();
289 BUG_ON(!irqs_disabled());
291 if ((error = device_power_down(PMSG_SUSPEND))) {
292 printk(KERN_ERR "PM: Some devices failed to power down\n");
293 goto Done;
296 if (!suspend_test(TEST_CORE))
297 error = suspend_ops->enter(state);
299 device_power_up(PMSG_RESUME);
300 Done:
301 arch_suspend_enable_irqs();
302 BUG_ON(irqs_disabled());
303 device_pm_unlock();
304 return error;
308 * suspend_devices_and_enter - suspend devices and enter the desired system
309 * sleep state.
310 * @state: state to enter
312 int suspend_devices_and_enter(suspend_state_t state)
314 int error, ftrace_save;
316 if (!suspend_ops)
317 return -ENOSYS;
319 if (suspend_ops->begin) {
320 error = suspend_ops->begin(state);
321 if (error)
322 goto Close;
324 suspend_console();
325 ftrace_save = __ftrace_enabled_save();
326 suspend_test_start();
327 error = device_suspend(PMSG_SUSPEND);
328 if (error) {
329 printk(KERN_ERR "PM: Some devices failed to suspend\n");
330 goto Recover_platform;
332 suspend_test_finish("suspend devices");
333 if (suspend_test(TEST_DEVICES))
334 goto Recover_platform;
336 if (suspend_ops->prepare) {
337 error = suspend_ops->prepare();
338 if (error)
339 goto Resume_devices;
342 if (suspend_test(TEST_PLATFORM))
343 goto Finish;
345 error = disable_nonboot_cpus();
346 if (!error && !suspend_test(TEST_CPUS))
347 suspend_enter(state);
349 enable_nonboot_cpus();
350 Finish:
351 if (suspend_ops->finish)
352 suspend_ops->finish();
353 Resume_devices:
354 suspend_test_start();
355 device_resume(PMSG_RESUME);
356 suspend_test_finish("resume devices");
357 __ftrace_enabled_restore(ftrace_save);
358 resume_console();
359 Close:
360 if (suspend_ops->end)
361 suspend_ops->end();
362 return error;
364 Recover_platform:
365 if (suspend_ops->recover)
366 suspend_ops->recover();
367 goto Resume_devices;
371 * suspend_finish - Do final work before exiting suspend sequence.
373 * Call platform code to clean up, restart processes, and free the
374 * console that we've allocated. This is not called for suspend-to-disk.
376 static void suspend_finish(void)
378 suspend_thaw_processes();
379 pm_notifier_call_chain(PM_POST_SUSPEND);
380 pm_restore_console();
386 static const char * const pm_states[PM_SUSPEND_MAX] = {
387 [PM_SUSPEND_STANDBY] = "standby",
388 [PM_SUSPEND_MEM] = "mem",
391 static inline int valid_state(suspend_state_t state)
393 /* All states need lowlevel support and need to be valid
394 * to the lowlevel implementation, no valid callback
395 * implies that none are valid. */
396 if (!suspend_ops || !suspend_ops->valid || !suspend_ops->valid(state))
397 return 0;
398 return 1;
403 * enter_state - Do common work of entering low-power state.
404 * @state: pm_state structure for state we're entering.
406 * Make sure we're the only ones trying to enter a sleep state. Fail
407 * if someone has beat us to it, since we don't want anything weird to
408 * happen when we wake up.
409 * Then, do the setup for suspend, enter the state, and cleaup (after
410 * we've woken up).
412 static int enter_state(suspend_state_t state)
414 int error;
416 if (!valid_state(state))
417 return -ENODEV;
419 if (!mutex_trylock(&pm_mutex))
420 return -EBUSY;
422 printk(KERN_INFO "PM: Syncing filesystems ... ");
423 sys_sync();
424 printk("done.\n");
426 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
427 error = suspend_prepare();
428 if (error)
429 goto Unlock;
431 if (suspend_test(TEST_FREEZER))
432 goto Finish;
434 pr_debug("PM: Entering %s sleep\n", pm_states[state]);
435 error = suspend_devices_and_enter(state);
437 Finish:
438 pr_debug("PM: Finishing wakeup.\n");
439 suspend_finish();
440 Unlock:
441 mutex_unlock(&pm_mutex);
442 return error;
447 * pm_suspend - Externally visible function for suspending system.
448 * @state: Enumerated value of state to enter.
450 * Determine whether or not value is within range, get state
451 * structure, and enter (above).
454 int pm_suspend(suspend_state_t state)
456 if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
457 return enter_state(state);
458 return -EINVAL;
461 EXPORT_SYMBOL(pm_suspend);
463 #endif /* CONFIG_SUSPEND */
465 struct kobject *power_kobj;
468 * state - control system power state.
470 * show() returns what states are supported, which is hard-coded to
471 * 'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and
472 * 'disk' (Suspend-to-Disk).
474 * store() accepts one of those strings, translates it into the
475 * proper enumerated value, and initiates a suspend transition.
478 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
479 char *buf)
481 char *s = buf;
482 #ifdef CONFIG_SUSPEND
483 int i;
485 for (i = 0; i < PM_SUSPEND_MAX; i++) {
486 if (pm_states[i] && valid_state(i))
487 s += sprintf(s,"%s ", pm_states[i]);
489 #endif
490 #ifdef CONFIG_HIBERNATION
491 s += sprintf(s, "%s\n", "disk");
492 #else
493 if (s != buf)
494 /* convert the last space to a newline */
495 *(s-1) = '\n';
496 #endif
497 return (s - buf);
500 static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
501 const char *buf, size_t n)
503 #ifdef CONFIG_SUSPEND
504 suspend_state_t state = PM_SUSPEND_STANDBY;
505 const char * const *s;
506 #endif
507 char *p;
508 int len;
509 int error = -EINVAL;
511 p = memchr(buf, '\n', n);
512 len = p ? p - buf : n;
514 /* First, check if we are requested to hibernate */
515 if (len == 4 && !strncmp(buf, "disk", len)) {
516 error = hibernate();
517 goto Exit;
520 #ifdef CONFIG_SUSPEND
521 for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
522 if (*s && len == strlen(*s) && !strncmp(buf, *s, len))
523 break;
525 if (state < PM_SUSPEND_MAX && *s)
526 error = enter_state(state);
527 #endif
529 Exit:
530 return error ? error : n;
533 power_attr(state);
535 #ifdef CONFIG_PM_TRACE
536 int pm_trace_enabled;
538 static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
539 char *buf)
541 return sprintf(buf, "%d\n", pm_trace_enabled);
544 static ssize_t
545 pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
546 const char *buf, size_t n)
548 int val;
550 if (sscanf(buf, "%d", &val) == 1) {
551 pm_trace_enabled = !!val;
552 return n;
554 return -EINVAL;
557 power_attr(pm_trace);
558 #endif /* CONFIG_PM_TRACE */
560 static struct attribute * g[] = {
561 &state_attr.attr,
562 #ifdef CONFIG_PM_TRACE
563 &pm_trace_attr.attr,
564 #endif
565 #if defined(CONFIG_PM_SLEEP) && defined(CONFIG_PM_DEBUG)
566 &pm_test_attr.attr,
567 #endif
568 NULL,
571 static struct attribute_group attr_group = {
572 .attrs = g,
576 static int __init pm_init(void)
578 power_kobj = kobject_create_and_add("power", NULL);
579 if (!power_kobj)
580 return -ENOMEM;
581 return sysfs_create_group(power_kobj, &attr_group);
584 core_initcall(pm_init);
587 #ifdef CONFIG_PM_TEST_SUSPEND
589 #include <linux/rtc.h>
592 * To test system suspend, we need a hands-off mechanism to resume the
593 * system. RTCs wake alarms are a common self-contained mechanism.
596 static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state)
598 static char err_readtime[] __initdata =
599 KERN_ERR "PM: can't read %s time, err %d\n";
600 static char err_wakealarm [] __initdata =
601 KERN_ERR "PM: can't set %s wakealarm, err %d\n";
602 static char err_suspend[] __initdata =
603 KERN_ERR "PM: suspend test failed, error %d\n";
604 static char info_test[] __initdata =
605 KERN_INFO "PM: test RTC wakeup from '%s' suspend\n";
607 unsigned long now;
608 struct rtc_wkalrm alm;
609 int status;
611 /* this may fail if the RTC hasn't been initialized */
612 status = rtc_read_time(rtc, &alm.time);
613 if (status < 0) {
614 printk(err_readtime, rtc->dev.bus_id, status);
615 return;
617 rtc_tm_to_time(&alm.time, &now);
619 memset(&alm, 0, sizeof alm);
620 rtc_time_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time);
621 alm.enabled = true;
623 status = rtc_set_alarm(rtc, &alm);
624 if (status < 0) {
625 printk(err_wakealarm, rtc->dev.bus_id, status);
626 return;
629 if (state == PM_SUSPEND_MEM) {
630 printk(info_test, pm_states[state]);
631 status = pm_suspend(state);
632 if (status == -ENODEV)
633 state = PM_SUSPEND_STANDBY;
635 if (state == PM_SUSPEND_STANDBY) {
636 printk(info_test, pm_states[state]);
637 status = pm_suspend(state);
639 if (status < 0)
640 printk(err_suspend, status);
642 /* Some platforms can't detect that the alarm triggered the
643 * wakeup, or (accordingly) disable it after it afterwards.
644 * It's supposed to give oneshot behavior; cope.
646 alm.enabled = false;
647 rtc_set_alarm(rtc, &alm);
650 static int __init has_wakealarm(struct device *dev, void *name_ptr)
652 struct rtc_device *candidate = to_rtc_device(dev);
654 if (!candidate->ops->set_alarm)
655 return 0;
656 if (!device_may_wakeup(candidate->dev.parent))
657 return 0;
659 *(char **)name_ptr = dev->bus_id;
660 return 1;
664 * Kernel options like "test_suspend=mem" force suspend/resume sanity tests
665 * at startup time. They're normally disabled, for faster boot and because
666 * we can't know which states really work on this particular system.
668 static suspend_state_t test_state __initdata = PM_SUSPEND_ON;
670 static char warn_bad_state[] __initdata =
671 KERN_WARNING "PM: can't test '%s' suspend state\n";
673 static int __init setup_test_suspend(char *value)
675 unsigned i;
677 /* "=mem" ==> "mem" */
678 value++;
679 for (i = 0; i < PM_SUSPEND_MAX; i++) {
680 if (!pm_states[i])
681 continue;
682 if (strcmp(pm_states[i], value) != 0)
683 continue;
684 test_state = (__force suspend_state_t) i;
685 return 0;
687 printk(warn_bad_state, value);
688 return 0;
690 __setup("test_suspend", setup_test_suspend);
692 static int __init test_suspend(void)
694 static char warn_no_rtc[] __initdata =
695 KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n";
697 char *pony = NULL;
698 struct rtc_device *rtc = NULL;
700 /* PM is initialized by now; is that state testable? */
701 if (test_state == PM_SUSPEND_ON)
702 goto done;
703 if (!valid_state(test_state)) {
704 printk(warn_bad_state, pm_states[test_state]);
705 goto done;
708 /* RTCs have initialized by now too ... can we use one? */
709 class_find_device(rtc_class, NULL, &pony, has_wakealarm);
710 if (pony)
711 rtc = rtc_class_open(pony);
712 if (!rtc) {
713 printk(warn_no_rtc);
714 goto done;
717 /* go for it */
718 test_wakealarm(rtc, test_state);
719 rtc_class_close(rtc);
720 done:
721 return 0;
723 late_initcall(test_suspend);
725 #endif /* CONFIG_PM_TEST_SUSPEND */