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1/*
2 * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
7 * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
8 *
9 * This file is released under the GPLv2.
10 */
11
12#include <linux/export.h>
13#include <linux/suspend.h>
14#include <linux/syscalls.h>
15#include <linux/reboot.h>
16#include <linux/string.h>
17#include <linux/device.h>
18#include <linux/async.h>
19#include <linux/delay.h>
20#include <linux/fs.h>
21#include <linux/mount.h>
22#include <linux/pm.h>
23#include <linux/console.h>
24#include <linux/cpu.h>
25#include <linux/freezer.h>
26#include <linux/gfp.h>
27#include <linux/syscore_ops.h>
28#include <linux/ctype.h>
29#include <linux/genhd.h>
30
31#include "power.h"
32
33
34static int nocompress;
35static int noresume;
36static int resume_wait;
37static int resume_delay;
38static char resume_file[256] = CONFIG_PM_STD_PARTITION;
39dev_t swsusp_resume_device;
40sector_t swsusp_resume_block;
41int in_suspend __nosavedata;
42
43enum {
44 HIBERNATION_INVALID,
45 HIBERNATION_PLATFORM,
46 HIBERNATION_SHUTDOWN,
47 HIBERNATION_REBOOT,
48 /* keep last */
49 __HIBERNATION_AFTER_LAST
50};
51#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
52#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
53
54static int hibernation_mode = HIBERNATION_SHUTDOWN;
55
56bool freezer_test_done;
57
58static const struct platform_hibernation_ops *hibernation_ops;
59
60/**
61 * hibernation_set_ops - Set the global hibernate operations.
62 * @ops: Hibernation operations to use in subsequent hibernation transitions.
63 */
64void hibernation_set_ops(const struct platform_hibernation_ops *ops)
65{
66 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
67 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
68 && ops->restore_cleanup && ops->leave)) {
69 WARN_ON(1);
70 return;
71 }
72 lock_system_sleep();
73 hibernation_ops = ops;
74 if (ops)
75 hibernation_mode = HIBERNATION_PLATFORM;
76 else if (hibernation_mode == HIBERNATION_PLATFORM)
77 hibernation_mode = HIBERNATION_SHUTDOWN;
78
79 unlock_system_sleep();
80}
81
82static bool entering_platform_hibernation;
83
84bool system_entering_hibernation(void)
85{
86 return entering_platform_hibernation;
87}
88EXPORT_SYMBOL(system_entering_hibernation);
89
90#ifdef CONFIG_PM_DEBUG
91static void hibernation_debug_sleep(void)
92{
93 printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
94 mdelay(5000);
95}
96
97static int hibernation_test(int level)
98{
99 if (pm_test_level == level) {
100 hibernation_debug_sleep();
101 return 1;
102 }
103 return 0;
104}
105#else /* !CONFIG_PM_DEBUG */
106static int hibernation_test(int level) { return 0; }
107#endif /* !CONFIG_PM_DEBUG */
108
109/**
110 * platform_begin - Call platform to start hibernation.
111 * @platform_mode: Whether or not to use the platform driver.
112 */
113static int platform_begin(int platform_mode)
114{
115 return (platform_mode && hibernation_ops) ?
116 hibernation_ops->begin() : 0;
117}
118
119/**
120 * platform_end - Call platform to finish transition to the working state.
121 * @platform_mode: Whether or not to use the platform driver.
122 */
123static void platform_end(int platform_mode)
124{
125 if (platform_mode && hibernation_ops)
126 hibernation_ops->end();
127}
128
129/**
130 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
131 * @platform_mode: Whether or not to use the platform driver.
132 *
133 * Use the platform driver to prepare the system for creating a hibernate image,
134 * if so configured, and return an error code if that fails.
135 */
136
137static int platform_pre_snapshot(int platform_mode)
138{
139 return (platform_mode && hibernation_ops) ?
140 hibernation_ops->pre_snapshot() : 0;
141}
142
143/**
144 * platform_leave - Call platform to prepare a transition to the working state.
145 * @platform_mode: Whether or not to use the platform driver.
146 *
147 * Use the platform driver prepare to prepare the machine for switching to the
148 * normal mode of operation.
149 *
150 * This routine is called on one CPU with interrupts disabled.
151 */
152static void platform_leave(int platform_mode)
153{
154 if (platform_mode && hibernation_ops)
155 hibernation_ops->leave();
156}
157
158/**
159 * platform_finish - Call platform to switch the system to the working state.
160 * @platform_mode: Whether or not to use the platform driver.
161 *
162 * Use the platform driver to switch the machine to the normal mode of
163 * operation.
164 *
165 * This routine must be called after platform_prepare().
166 */
167static void platform_finish(int platform_mode)
168{
169 if (platform_mode && hibernation_ops)
170 hibernation_ops->finish();
171}
172
173/**
174 * platform_pre_restore - Prepare for hibernate image restoration.
175 * @platform_mode: Whether or not to use the platform driver.
176 *
177 * Use the platform driver to prepare the system for resume from a hibernation
178 * image.
179 *
180 * If the restore fails after this function has been called,
181 * platform_restore_cleanup() must be called.
182 */
183static int platform_pre_restore(int platform_mode)
184{
185 return (platform_mode && hibernation_ops) ?
186 hibernation_ops->pre_restore() : 0;
187}
188
189/**
190 * platform_restore_cleanup - Switch to the working state after failing restore.
191 * @platform_mode: Whether or not to use the platform driver.
192 *
193 * Use the platform driver to switch the system to the normal mode of operation
194 * after a failing restore.
195 *
196 * If platform_pre_restore() has been called before the failing restore, this
197 * function must be called too, regardless of the result of
198 * platform_pre_restore().
199 */
200static void platform_restore_cleanup(int platform_mode)
201{
202 if (platform_mode && hibernation_ops)
203 hibernation_ops->restore_cleanup();
204}
205
206/**
207 * platform_recover - Recover from a failure to suspend devices.
208 * @platform_mode: Whether or not to use the platform driver.
209 */
210static void platform_recover(int platform_mode)
211{
212 if (platform_mode && hibernation_ops && hibernation_ops->recover)
213 hibernation_ops->recover();
214}
215
216/**
217 * swsusp_show_speed - Print time elapsed between two events during hibernation.
218 * @start: Starting event.
219 * @stop: Final event.
220 * @nr_pages: Number of memory pages processed between @start and @stop.
221 * @msg: Additional diagnostic message to print.
222 */
223void swsusp_show_speed(struct timeval *start, struct timeval *stop,
224 unsigned nr_pages, char *msg)
225{
226 s64 elapsed_centisecs64;
227 int centisecs;
228 int k;
229 int kps;
230
231 elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
232 do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
233 centisecs = elapsed_centisecs64;
234 if (centisecs == 0)
235 centisecs = 1; /* avoid div-by-zero */
236 k = nr_pages * (PAGE_SIZE / 1024);
237 kps = (k * 100) / centisecs;
238 printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
239 msg, k,
240 centisecs / 100, centisecs % 100,
241 kps / 1000, (kps % 1000) / 10);
242}
243
244/**
245 * create_image - Create a hibernation image.
246 * @platform_mode: Whether or not to use the platform driver.
247 *
248 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
249 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
250 *
251 * Control reappears in this routine after the subsequent restore.
252 */
253static int create_image(int platform_mode)
254{
255 int error;
256
257 error = dpm_suspend_end(PMSG_FREEZE);
258 if (error) {
259 printk(KERN_ERR "PM: Some devices failed to power down, "
260 "aborting hibernation\n");
261 return error;
262 }
263
264 error = platform_pre_snapshot(platform_mode);
265 if (error || hibernation_test(TEST_PLATFORM))
266 goto Platform_finish;
267
268 error = disable_nonboot_cpus();
269 if (error || hibernation_test(TEST_CPUS))
270 goto Enable_cpus;
271
272 local_irq_disable();
273
274 error = syscore_suspend();
275 if (error) {
276 printk(KERN_ERR "PM: Some system devices failed to power down, "
277 "aborting hibernation\n");
278 goto Enable_irqs;
279 }
280
281 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
282 goto Power_up;
283
284 in_suspend = 1;
285 save_processor_state();
286 error = swsusp_arch_suspend();
287 if (error)
288 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
289 error);
290 /* Restore control flow magically appears here */
291 restore_processor_state();
292 if (!in_suspend) {
293 events_check_enabled = false;
294 platform_leave(platform_mode);
295 }
296
297 Power_up:
298 syscore_resume();
299
300 Enable_irqs:
301 local_irq_enable();
302
303 Enable_cpus:
304 enable_nonboot_cpus();
305
306 Platform_finish:
307 platform_finish(platform_mode);
308
309 dpm_resume_start(in_suspend ?
310 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
311
312 return error;
313}
314
315/**
316 * hibernation_snapshot - Quiesce devices and create a hibernation image.
317 * @platform_mode: If set, use platform driver to prepare for the transition.
318 *
319 * This routine must be called with pm_mutex held.
320 */
321int hibernation_snapshot(int platform_mode)
322{
323 pm_message_t msg;
324 int error;
325
326 error = platform_begin(platform_mode);
327 if (error)
328 goto Close;
329
330 /* Preallocate image memory before shutting down devices. */
331 error = hibernate_preallocate_memory();
332 if (error)
333 goto Close;
334
335 error = freeze_kernel_threads();
336 if (error)
337 goto Cleanup;
338
339 if (hibernation_test(TEST_FREEZER)) {
340
341 /*
342 * Indicate to the caller that we are returning due to a
343 * successful freezer test.
344 */
345 freezer_test_done = true;
346 goto Thaw;
347 }
348
349 error = dpm_prepare(PMSG_FREEZE);
350 if (error) {
351 dpm_complete(PMSG_RECOVER);
352 goto Thaw;
353 }
354
355 suspend_console();
356 ftrace_stop();
357 pm_restrict_gfp_mask();
358
359 error = dpm_suspend(PMSG_FREEZE);
360
361 if (error || hibernation_test(TEST_DEVICES))
362 platform_recover(platform_mode);
363 else
364 error = create_image(platform_mode);
365
366 /*
367 * In the case that we call create_image() above, the control
368 * returns here (1) after the image has been created or the
369 * image creation has failed and (2) after a successful restore.
370 */
371
372 /* We may need to release the preallocated image pages here. */
373 if (error || !in_suspend)
374 swsusp_free();
375
376 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
377 dpm_resume(msg);
378
379 if (error || !in_suspend)
380 pm_restore_gfp_mask();
381
382 ftrace_start();
383 resume_console();
384 dpm_complete(msg);
385
386 Close:
387 platform_end(platform_mode);
388 return error;
389
390 Thaw:
391 thaw_kernel_threads();
392 Cleanup:
393 swsusp_free();
394 goto Close;
395}
396
397/**
398 * resume_target_kernel - Restore system state from a hibernation image.
399 * @platform_mode: Whether or not to use the platform driver.
400 *
401 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
402 * contents of highmem that have not been restored yet from the image and run
403 * the low-level code that will restore the remaining contents of memory and
404 * switch to the just restored target kernel.
405 */
406static int resume_target_kernel(bool platform_mode)
407{
408 int error;
409
410 error = dpm_suspend_end(PMSG_QUIESCE);
411 if (error) {
412 printk(KERN_ERR "PM: Some devices failed to power down, "
413 "aborting resume\n");
414 return error;
415 }
416
417 error = platform_pre_restore(platform_mode);
418 if (error)
419 goto Cleanup;
420
421 error = disable_nonboot_cpus();
422 if (error)
423 goto Enable_cpus;
424
425 local_irq_disable();
426
427 error = syscore_suspend();
428 if (error)
429 goto Enable_irqs;
430
431 save_processor_state();
432 error = restore_highmem();
433 if (!error) {
434 error = swsusp_arch_resume();
435 /*
436 * The code below is only ever reached in case of a failure.
437 * Otherwise, execution continues at the place where
438 * swsusp_arch_suspend() was called.
439 */
440 BUG_ON(!error);
441 /*
442 * This call to restore_highmem() reverts the changes made by
443 * the previous one.
444 */
445 restore_highmem();
446 }
447 /*
448 * The only reason why swsusp_arch_resume() can fail is memory being
449 * very tight, so we have to free it as soon as we can to avoid
450 * subsequent failures.
451 */
452 swsusp_free();
453 restore_processor_state();
454 touch_softlockup_watchdog();
455
456 syscore_resume();
457
458 Enable_irqs:
459 local_irq_enable();
460
461 Enable_cpus:
462 enable_nonboot_cpus();
463
464 Cleanup:
465 platform_restore_cleanup(platform_mode);
466
467 dpm_resume_start(PMSG_RECOVER);
468
469 return error;
470}
471
472/**
473 * hibernation_restore - Quiesce devices and restore from a hibernation image.
474 * @platform_mode: If set, use platform driver to prepare for the transition.
475 *
476 * This routine must be called with pm_mutex held. If it is successful, control
477 * reappears in the restored target kernel in hibernation_snapshot().
478 */
479int hibernation_restore(int platform_mode)
480{
481 int error;
482
483 pm_prepare_console();
484 suspend_console();
485 ftrace_stop();
486 pm_restrict_gfp_mask();
487 error = dpm_suspend_start(PMSG_QUIESCE);
488 if (!error) {
489 error = resume_target_kernel(platform_mode);
490 dpm_resume_end(PMSG_RECOVER);
491 }
492 pm_restore_gfp_mask();
493 ftrace_start();
494 resume_console();
495 pm_restore_console();
496 return error;
497}
498
499/**
500 * hibernation_platform_enter - Power off the system using the platform driver.
501 */
502int hibernation_platform_enter(void)
503{
504 int error;
505
506 if (!hibernation_ops)
507 return -ENOSYS;
508
509 /*
510 * We have cancelled the power transition by running
511 * hibernation_ops->finish() before saving the image, so we should let
512 * the firmware know that we're going to enter the sleep state after all
513 */
514 error = hibernation_ops->begin();
515 if (error)
516 goto Close;
517
518 entering_platform_hibernation = true;
519 suspend_console();
520 ftrace_stop();
521 error = dpm_suspend_start(PMSG_HIBERNATE);
522 if (error) {
523 if (hibernation_ops->recover)
524 hibernation_ops->recover();
525 goto Resume_devices;
526 }
527
528 error = dpm_suspend_end(PMSG_HIBERNATE);
529 if (error)
530 goto Resume_devices;
531
532 error = hibernation_ops->prepare();
533 if (error)
534 goto Platform_finish;
535
536 error = disable_nonboot_cpus();
537 if (error)
538 goto Platform_finish;
539
540 local_irq_disable();
541 syscore_suspend();
542 if (pm_wakeup_pending()) {
543 error = -EAGAIN;
544 goto Power_up;
545 }
546
547 hibernation_ops->enter();
548 /* We should never get here */
549 while (1);
550
551 Power_up:
552 syscore_resume();
553 local_irq_enable();
554 enable_nonboot_cpus();
555
556 Platform_finish:
557 hibernation_ops->finish();
558
559 dpm_resume_start(PMSG_RESTORE);
560
561 Resume_devices:
562 entering_platform_hibernation = false;
563 dpm_resume_end(PMSG_RESTORE);
564 ftrace_start();
565 resume_console();
566
567 Close:
568 hibernation_ops->end();
569
570 return error;
571}
572
573/**
574 * power_down - Shut the machine down for hibernation.
575 *
576 * Use the platform driver, if configured, to put the system into the sleep
577 * state corresponding to hibernation, or try to power it off or reboot,
578 * depending on the value of hibernation_mode.
579 */
580static void power_down(void)
581{
582 switch (hibernation_mode) {
583 case HIBERNATION_REBOOT:
584 kernel_restart(NULL);
585 break;
586 case HIBERNATION_PLATFORM:
587 hibernation_platform_enter();
588 case HIBERNATION_SHUTDOWN:
589 kernel_power_off();
590 break;
591 }
592 kernel_halt();
593 /*
594 * Valid image is on the disk, if we continue we risk serious data
595 * corruption after resume.
596 */
597 printk(KERN_CRIT "PM: Please power down manually\n");
598 while(1);
599}
600
601/**
602 * hibernate - Carry out system hibernation, including saving the image.
603 */
604int hibernate(void)
605{
606 int error;
607
608 lock_system_sleep();
609 /* The snapshot device should not be opened while we're running */
610 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
611 error = -EBUSY;
612 goto Unlock;
613 }
614
615 pm_prepare_console();
616 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
617 if (error)
618 goto Exit;
619
620 /* Allocate memory management structures */
621 error = create_basic_memory_bitmaps();
622 if (error)
623 goto Exit;
624
625 printk(KERN_INFO "PM: Syncing filesystems ... ");
626 sys_sync();
627 printk("done.\n");
628
629 error = freeze_processes();
630 if (error)
631 goto Free_bitmaps;
632
633 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
634 if (error || freezer_test_done)
635 goto Thaw;
636
637 if (in_suspend) {
638 unsigned int flags = 0;
639
640 if (hibernation_mode == HIBERNATION_PLATFORM)
641 flags |= SF_PLATFORM_MODE;
642 if (nocompress)
643 flags |= SF_NOCOMPRESS_MODE;
644 else
645 flags |= SF_CRC32_MODE;
646
647 pr_debug("PM: writing image.\n");
648 error = swsusp_write(flags);
649 swsusp_free();
650 if (!error)
651 power_down();
652 in_suspend = 0;
653 pm_restore_gfp_mask();
654 } else {
655 pr_debug("PM: Image restored successfully.\n");
656 }
657
658 Thaw:
659 thaw_processes();
660
661 /* Don't bother checking whether freezer_test_done is true */
662 freezer_test_done = false;
663
664 Free_bitmaps:
665 free_basic_memory_bitmaps();
666 Exit:
667 pm_notifier_call_chain(PM_POST_HIBERNATION);
668 pm_restore_console();
669 atomic_inc(&snapshot_device_available);
670 Unlock:
671 unlock_system_sleep();
672 return error;
673}
674
675
676/**
677 * software_resume - Resume from a saved hibernation image.
678 *
679 * This routine is called as a late initcall, when all devices have been
680 * discovered and initialized already.
681 *
682 * The image reading code is called to see if there is a hibernation image
683 * available for reading. If that is the case, devices are quiesced and the
684 * contents of memory is restored from the saved image.
685 *
686 * If this is successful, control reappears in the restored target kernel in
687 * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine
688 * attempts to recover gracefully and make the kernel return to the normal mode
689 * of operation.
690 */
691static int software_resume(void)
692{
693 int error;
694 unsigned int flags;
695
696 /*
697 * If the user said "noresume".. bail out early.
698 */
699 if (noresume)
700 return 0;
701
702 /*
703 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
704 * is configured into the kernel. Since the regular hibernate
705 * trigger path is via sysfs which takes a buffer mutex before
706 * calling hibernate functions (which take pm_mutex) this can
707 * cause lockdep to complain about a possible ABBA deadlock
708 * which cannot happen since we're in the boot code here and
709 * sysfs can't be invoked yet. Therefore, we use a subclass
710 * here to avoid lockdep complaining.
711 */
712 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
713
714 if (swsusp_resume_device)
715 goto Check_image;
716
717 if (!strlen(resume_file)) {
718 error = -ENOENT;
719 goto Unlock;
720 }
721
722 pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
723
724 if (resume_delay) {
725 printk(KERN_INFO "Waiting %dsec before reading resume device...\n",
726 resume_delay);
727 ssleep(resume_delay);
728 }
729
730 /* Check if the device is there */
731 swsusp_resume_device = name_to_dev_t(resume_file);
732
733 /*
734 * name_to_dev_t is ineffective to verify parition if resume_file is in
735 * integer format. (e.g. major:minor)
736 */
737 if (isdigit(resume_file[0]) && resume_wait) {
738 int partno;
739 while (!get_gendisk(swsusp_resume_device, &partno))
740 msleep(10);
741 }
742
743 if (!swsusp_resume_device) {
744 /*
745 * Some device discovery might still be in progress; we need
746 * to wait for this to finish.
747 */
748 wait_for_device_probe();
749
750 if (resume_wait) {
751 while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
752 msleep(10);
753 async_synchronize_full();
754 }
755
756 swsusp_resume_device = name_to_dev_t(resume_file);
757 if (!swsusp_resume_device) {
758 error = -ENODEV;
759 goto Unlock;
760 }
761 }
762
763 Check_image:
764 pr_debug("PM: Hibernation image partition %d:%d present\n",
765 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
766
767 pr_debug("PM: Looking for hibernation image.\n");
768 error = swsusp_check();
769 if (error)
770 goto Unlock;
771
772 /* The snapshot device should not be opened while we're running */
773 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
774 error = -EBUSY;
775 swsusp_close(FMODE_READ);
776 goto Unlock;
777 }
778
779 pm_prepare_console();
780 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
781 if (error)
782 goto close_finish;
783
784 error = create_basic_memory_bitmaps();
785 if (error)
786 goto close_finish;
787
788 pr_debug("PM: Preparing processes for restore.\n");
789 error = freeze_processes();
790 if (error) {
791 swsusp_close(FMODE_READ);
792 goto Done;
793 }
794
795 pr_debug("PM: Loading hibernation image.\n");
796
797 error = swsusp_read(&flags);
798 swsusp_close(FMODE_READ);
799 if (!error)
800 hibernation_restore(flags & SF_PLATFORM_MODE);
801
802 printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
803 swsusp_free();
804 thaw_processes();
805 Done:
806 free_basic_memory_bitmaps();
807 Finish:
808 pm_notifier_call_chain(PM_POST_RESTORE);
809 pm_restore_console();
810 atomic_inc(&snapshot_device_available);
811 /* For success case, the suspend path will release the lock */
812 Unlock:
813 mutex_unlock(&pm_mutex);
814 pr_debug("PM: Hibernation image not present or could not be loaded.\n");
815 return error;
816close_finish:
817 swsusp_close(FMODE_READ);
818 goto Finish;
819}
820
821late_initcall(software_resume);
822
823
824static const char * const hibernation_modes[] = {
825 [HIBERNATION_PLATFORM] = "platform",
826 [HIBERNATION_SHUTDOWN] = "shutdown",
827 [HIBERNATION_REBOOT] = "reboot",
828};
829
830/*
831 * /sys/power/disk - Control hibernation mode.
832 *
833 * Hibernation can be handled in several ways. There are a few different ways
834 * to put the system into the sleep state: using the platform driver (e.g. ACPI
835 * or other hibernation_ops), powering it off or rebooting it (for testing
836 * mostly).
837 *
838 * The sysfs file /sys/power/disk provides an interface for selecting the
839 * hibernation mode to use. Reading from this file causes the available modes
840 * to be printed. There are 3 modes that can be supported:
841 *
842 * 'platform'
843 * 'shutdown'
844 * 'reboot'
845 *
846 * If a platform hibernation driver is in use, 'platform' will be supported
847 * and will be used by default. Otherwise, 'shutdown' will be used by default.
848 * The selected option (i.e. the one corresponding to the current value of
849 * hibernation_mode) is enclosed by a square bracket.
850 *
851 * To select a given hibernation mode it is necessary to write the mode's
852 * string representation (as returned by reading from /sys/power/disk) back
853 * into /sys/power/disk.
854 */
855
856static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
857 char *buf)
858{
859 int i;
860 char *start = buf;
861
862 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
863 if (!hibernation_modes[i])
864 continue;
865 switch (i) {
866 case HIBERNATION_SHUTDOWN:
867 case HIBERNATION_REBOOT:
868 break;
869 case HIBERNATION_PLATFORM:
870 if (hibernation_ops)
871 break;
872 /* not a valid mode, continue with loop */
873 continue;
874 }
875 if (i == hibernation_mode)
876 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
877 else
878 buf += sprintf(buf, "%s ", hibernation_modes[i]);
879 }
880 buf += sprintf(buf, "\n");
881 return buf-start;
882}
883
884static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
885 const char *buf, size_t n)
886{
887 int error = 0;
888 int i;
889 int len;
890 char *p;
891 int mode = HIBERNATION_INVALID;
892
893 p = memchr(buf, '\n', n);
894 len = p ? p - buf : n;
895
896 lock_system_sleep();
897 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
898 if (len == strlen(hibernation_modes[i])
899 && !strncmp(buf, hibernation_modes[i], len)) {
900 mode = i;
901 break;
902 }
903 }
904 if (mode != HIBERNATION_INVALID) {
905 switch (mode) {
906 case HIBERNATION_SHUTDOWN:
907 case HIBERNATION_REBOOT:
908 hibernation_mode = mode;
909 break;
910 case HIBERNATION_PLATFORM:
911 if (hibernation_ops)
912 hibernation_mode = mode;
913 else
914 error = -EINVAL;
915 }
916 } else
917 error = -EINVAL;
918
919 if (!error)
920 pr_debug("PM: Hibernation mode set to '%s'\n",
921 hibernation_modes[mode]);
922 unlock_system_sleep();
923 return error ? error : n;
924}
925
926power_attr(disk);
927
928static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
929 char *buf)
930{
931 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
932 MINOR(swsusp_resume_device));
933}
934
935static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
936 const char *buf, size_t n)
937{
938 unsigned int maj, min;
939 dev_t res;
940 int ret = -EINVAL;
941
942 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
943 goto out;
944
945 res = MKDEV(maj,min);
946 if (maj != MAJOR(res) || min != MINOR(res))
947 goto out;
948
949 lock_system_sleep();
950 swsusp_resume_device = res;
951 unlock_system_sleep();
952 printk(KERN_INFO "PM: Starting manual resume from disk\n");
953 noresume = 0;
954 software_resume();
955 ret = n;
956 out:
957 return ret;
958}
959
960power_attr(resume);
961
962static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
963 char *buf)
964{
965 return sprintf(buf, "%lu\n", image_size);
966}
967
968static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
969 const char *buf, size_t n)
970{
971 unsigned long size;
972
973 if (sscanf(buf, "%lu", &size) == 1) {
974 image_size = size;
975 return n;
976 }
977
978 return -EINVAL;
979}
980
981power_attr(image_size);
982
983static ssize_t reserved_size_show(struct kobject *kobj,
984 struct kobj_attribute *attr, char *buf)
985{
986 return sprintf(buf, "%lu\n", reserved_size);
987}
988
989static ssize_t reserved_size_store(struct kobject *kobj,
990 struct kobj_attribute *attr,
991 const char *buf, size_t n)
992{
993 unsigned long size;
994
995 if (sscanf(buf, "%lu", &size) == 1) {
996 reserved_size = size;
997 return n;
998 }
999
1000 return -EINVAL;
1001}
1002
1003power_attr(reserved_size);
1004
1005static struct attribute * g[] = {
1006 &disk_attr.attr,
1007 &resume_attr.attr,
1008 &image_size_attr.attr,
1009 &reserved_size_attr.attr,
1010 NULL,
1011};
1012
1013
1014static struct attribute_group attr_group = {
1015 .attrs = g,
1016};
1017
1018
1019static int __init pm_disk_init(void)
1020{
1021 return sysfs_create_group(power_kobj, &attr_group);
1022}
1023
1024core_initcall(pm_disk_init);
1025
1026
1027static int __init resume_setup(char *str)
1028{
1029 if (noresume)
1030 return 1;
1031
1032 strncpy( resume_file, str, 255 );
1033 return 1;
1034}
1035
1036static int __init resume_offset_setup(char *str)
1037{
1038 unsigned long long offset;
1039
1040 if (noresume)
1041 return 1;
1042
1043 if (sscanf(str, "%llu", &offset) == 1)
1044 swsusp_resume_block = offset;
1045
1046 return 1;
1047}
1048
1049static int __init hibernate_setup(char *str)
1050{
1051 if (!strncmp(str, "noresume", 8))
1052 noresume = 1;
1053 else if (!strncmp(str, "nocompress", 10))
1054 nocompress = 1;
1055 return 1;
1056}
1057
1058static int __init noresume_setup(char *str)
1059{
1060 noresume = 1;
1061 return 1;
1062}
1063
1064static int __init resumewait_setup(char *str)
1065{
1066 resume_wait = 1;
1067 return 1;
1068}
1069
1070static int __init resumedelay_setup(char *str)
1071{
1072 resume_delay = simple_strtoul(str, NULL, 0);
1073 return 1;
1074}
1075
1076__setup("noresume", noresume_setup);
1077__setup("resume_offset=", resume_offset_setup);
1078__setup("resume=", resume_setup);
1079__setup("hibernate=", hibernate_setup);
1080__setup("resumewait", resumewait_setup);
1081__setup("resumedelay=", resumedelay_setup);
1/*
2 * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
7 * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
8 * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
9 *
10 * This file is released under the GPLv2.
11 */
12
13#include <linux/export.h>
14#include <linux/suspend.h>
15#include <linux/syscalls.h>
16#include <linux/reboot.h>
17#include <linux/string.h>
18#include <linux/device.h>
19#include <linux/async.h>
20#include <linux/delay.h>
21#include <linux/fs.h>
22#include <linux/mount.h>
23#include <linux/pm.h>
24#include <linux/console.h>
25#include <linux/cpu.h>
26#include <linux/freezer.h>
27#include <linux/gfp.h>
28#include <linux/syscore_ops.h>
29#include <linux/ctype.h>
30#include <linux/genhd.h>
31#include <linux/ktime.h>
32#include <trace/events/power.h>
33
34#include "power.h"
35
36
37static int nocompress;
38static int noresume;
39static int nohibernate;
40static int resume_wait;
41static unsigned int resume_delay;
42static char resume_file[256] = CONFIG_PM_STD_PARTITION;
43dev_t swsusp_resume_device;
44sector_t swsusp_resume_block;
45__visible int in_suspend __nosavedata;
46
47enum {
48 HIBERNATION_INVALID,
49 HIBERNATION_PLATFORM,
50 HIBERNATION_SHUTDOWN,
51 HIBERNATION_REBOOT,
52#ifdef CONFIG_SUSPEND
53 HIBERNATION_SUSPEND,
54#endif
55 HIBERNATION_TEST_RESUME,
56 /* keep last */
57 __HIBERNATION_AFTER_LAST
58};
59#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
60#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
61
62static int hibernation_mode = HIBERNATION_SHUTDOWN;
63
64bool freezer_test_done;
65
66static const struct platform_hibernation_ops *hibernation_ops;
67
68bool hibernation_available(void)
69{
70 return (nohibernate == 0);
71}
72
73/**
74 * hibernation_set_ops - Set the global hibernate operations.
75 * @ops: Hibernation operations to use in subsequent hibernation transitions.
76 */
77void hibernation_set_ops(const struct platform_hibernation_ops *ops)
78{
79 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
80 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
81 && ops->restore_cleanup && ops->leave)) {
82 WARN_ON(1);
83 return;
84 }
85 lock_system_sleep();
86 hibernation_ops = ops;
87 if (ops)
88 hibernation_mode = HIBERNATION_PLATFORM;
89 else if (hibernation_mode == HIBERNATION_PLATFORM)
90 hibernation_mode = HIBERNATION_SHUTDOWN;
91
92 unlock_system_sleep();
93}
94EXPORT_SYMBOL_GPL(hibernation_set_ops);
95
96static bool entering_platform_hibernation;
97
98bool system_entering_hibernation(void)
99{
100 return entering_platform_hibernation;
101}
102EXPORT_SYMBOL(system_entering_hibernation);
103
104#ifdef CONFIG_PM_DEBUG
105static void hibernation_debug_sleep(void)
106{
107 printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
108 mdelay(5000);
109}
110
111static int hibernation_test(int level)
112{
113 if (pm_test_level == level) {
114 hibernation_debug_sleep();
115 return 1;
116 }
117 return 0;
118}
119#else /* !CONFIG_PM_DEBUG */
120static int hibernation_test(int level) { return 0; }
121#endif /* !CONFIG_PM_DEBUG */
122
123/**
124 * platform_begin - Call platform to start hibernation.
125 * @platform_mode: Whether or not to use the platform driver.
126 */
127static int platform_begin(int platform_mode)
128{
129 return (platform_mode && hibernation_ops) ?
130 hibernation_ops->begin() : 0;
131}
132
133/**
134 * platform_end - Call platform to finish transition to the working state.
135 * @platform_mode: Whether or not to use the platform driver.
136 */
137static void platform_end(int platform_mode)
138{
139 if (platform_mode && hibernation_ops)
140 hibernation_ops->end();
141}
142
143/**
144 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
145 * @platform_mode: Whether or not to use the platform driver.
146 *
147 * Use the platform driver to prepare the system for creating a hibernate image,
148 * if so configured, and return an error code if that fails.
149 */
150
151static int platform_pre_snapshot(int platform_mode)
152{
153 return (platform_mode && hibernation_ops) ?
154 hibernation_ops->pre_snapshot() : 0;
155}
156
157/**
158 * platform_leave - Call platform to prepare a transition to the working state.
159 * @platform_mode: Whether or not to use the platform driver.
160 *
161 * Use the platform driver prepare to prepare the machine for switching to the
162 * normal mode of operation.
163 *
164 * This routine is called on one CPU with interrupts disabled.
165 */
166static void platform_leave(int platform_mode)
167{
168 if (platform_mode && hibernation_ops)
169 hibernation_ops->leave();
170}
171
172/**
173 * platform_finish - Call platform to switch the system to the working state.
174 * @platform_mode: Whether or not to use the platform driver.
175 *
176 * Use the platform driver to switch the machine to the normal mode of
177 * operation.
178 *
179 * This routine must be called after platform_prepare().
180 */
181static void platform_finish(int platform_mode)
182{
183 if (platform_mode && hibernation_ops)
184 hibernation_ops->finish();
185}
186
187/**
188 * platform_pre_restore - Prepare for hibernate image restoration.
189 * @platform_mode: Whether or not to use the platform driver.
190 *
191 * Use the platform driver to prepare the system for resume from a hibernation
192 * image.
193 *
194 * If the restore fails after this function has been called,
195 * platform_restore_cleanup() must be called.
196 */
197static int platform_pre_restore(int platform_mode)
198{
199 return (platform_mode && hibernation_ops) ?
200 hibernation_ops->pre_restore() : 0;
201}
202
203/**
204 * platform_restore_cleanup - Switch to the working state after failing restore.
205 * @platform_mode: Whether or not to use the platform driver.
206 *
207 * Use the platform driver to switch the system to the normal mode of operation
208 * after a failing restore.
209 *
210 * If platform_pre_restore() has been called before the failing restore, this
211 * function must be called too, regardless of the result of
212 * platform_pre_restore().
213 */
214static void platform_restore_cleanup(int platform_mode)
215{
216 if (platform_mode && hibernation_ops)
217 hibernation_ops->restore_cleanup();
218}
219
220/**
221 * platform_recover - Recover from a failure to suspend devices.
222 * @platform_mode: Whether or not to use the platform driver.
223 */
224static void platform_recover(int platform_mode)
225{
226 if (platform_mode && hibernation_ops && hibernation_ops->recover)
227 hibernation_ops->recover();
228}
229
230/**
231 * swsusp_show_speed - Print time elapsed between two events during hibernation.
232 * @start: Starting event.
233 * @stop: Final event.
234 * @nr_pages: Number of memory pages processed between @start and @stop.
235 * @msg: Additional diagnostic message to print.
236 */
237void swsusp_show_speed(ktime_t start, ktime_t stop,
238 unsigned nr_pages, char *msg)
239{
240 ktime_t diff;
241 u64 elapsed_centisecs64;
242 unsigned int centisecs;
243 unsigned int k;
244 unsigned int kps;
245
246 diff = ktime_sub(stop, start);
247 elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
248 centisecs = elapsed_centisecs64;
249 if (centisecs == 0)
250 centisecs = 1; /* avoid div-by-zero */
251 k = nr_pages * (PAGE_SIZE / 1024);
252 kps = (k * 100) / centisecs;
253 printk(KERN_INFO "PM: %s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
254 msg, k,
255 centisecs / 100, centisecs % 100,
256 kps / 1000, (kps % 1000) / 10);
257}
258
259/**
260 * create_image - Create a hibernation image.
261 * @platform_mode: Whether or not to use the platform driver.
262 *
263 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
264 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
265 *
266 * Control reappears in this routine after the subsequent restore.
267 */
268static int create_image(int platform_mode)
269{
270 int error;
271
272 error = dpm_suspend_end(PMSG_FREEZE);
273 if (error) {
274 printk(KERN_ERR "PM: Some devices failed to power down, "
275 "aborting hibernation\n");
276 return error;
277 }
278
279 error = platform_pre_snapshot(platform_mode);
280 if (error || hibernation_test(TEST_PLATFORM))
281 goto Platform_finish;
282
283 error = disable_nonboot_cpus();
284 if (error || hibernation_test(TEST_CPUS))
285 goto Enable_cpus;
286
287 local_irq_disable();
288
289 error = syscore_suspend();
290 if (error) {
291 printk(KERN_ERR "PM: Some system devices failed to power down, "
292 "aborting hibernation\n");
293 goto Enable_irqs;
294 }
295
296 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
297 goto Power_up;
298
299 in_suspend = 1;
300 save_processor_state();
301 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
302 error = swsusp_arch_suspend();
303 /* Restore control flow magically appears here */
304 restore_processor_state();
305 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
306 if (error)
307 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
308 error);
309 if (!in_suspend) {
310 events_check_enabled = false;
311 clear_free_pages();
312 }
313
314 platform_leave(platform_mode);
315
316 Power_up:
317 syscore_resume();
318
319 Enable_irqs:
320 local_irq_enable();
321
322 Enable_cpus:
323 enable_nonboot_cpus();
324
325 Platform_finish:
326 platform_finish(platform_mode);
327
328 dpm_resume_start(in_suspend ?
329 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
330
331 return error;
332}
333
334/**
335 * hibernation_snapshot - Quiesce devices and create a hibernation image.
336 * @platform_mode: If set, use platform driver to prepare for the transition.
337 *
338 * This routine must be called with pm_mutex held.
339 */
340int hibernation_snapshot(int platform_mode)
341{
342 pm_message_t msg;
343 int error;
344
345 pm_suspend_clear_flags();
346 error = platform_begin(platform_mode);
347 if (error)
348 goto Close;
349
350 /* Preallocate image memory before shutting down devices. */
351 error = hibernate_preallocate_memory();
352 if (error)
353 goto Close;
354
355 error = freeze_kernel_threads();
356 if (error)
357 goto Cleanup;
358
359 if (hibernation_test(TEST_FREEZER)) {
360
361 /*
362 * Indicate to the caller that we are returning due to a
363 * successful freezer test.
364 */
365 freezer_test_done = true;
366 goto Thaw;
367 }
368
369 error = dpm_prepare(PMSG_FREEZE);
370 if (error) {
371 dpm_complete(PMSG_RECOVER);
372 goto Thaw;
373 }
374
375 suspend_console();
376 pm_restrict_gfp_mask();
377
378 error = dpm_suspend(PMSG_FREEZE);
379
380 if (error || hibernation_test(TEST_DEVICES))
381 platform_recover(platform_mode);
382 else
383 error = create_image(platform_mode);
384
385 /*
386 * In the case that we call create_image() above, the control
387 * returns here (1) after the image has been created or the
388 * image creation has failed and (2) after a successful restore.
389 */
390
391 /* We may need to release the preallocated image pages here. */
392 if (error || !in_suspend)
393 swsusp_free();
394
395 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
396 dpm_resume(msg);
397
398 if (error || !in_suspend)
399 pm_restore_gfp_mask();
400
401 resume_console();
402 dpm_complete(msg);
403
404 Close:
405 platform_end(platform_mode);
406 return error;
407
408 Thaw:
409 thaw_kernel_threads();
410 Cleanup:
411 swsusp_free();
412 goto Close;
413}
414
415int __weak hibernate_resume_nonboot_cpu_disable(void)
416{
417 return disable_nonboot_cpus();
418}
419
420/**
421 * resume_target_kernel - Restore system state from a hibernation image.
422 * @platform_mode: Whether or not to use the platform driver.
423 *
424 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
425 * contents of highmem that have not been restored yet from the image and run
426 * the low-level code that will restore the remaining contents of memory and
427 * switch to the just restored target kernel.
428 */
429static int resume_target_kernel(bool platform_mode)
430{
431 int error;
432
433 error = dpm_suspend_end(PMSG_QUIESCE);
434 if (error) {
435 printk(KERN_ERR "PM: Some devices failed to power down, "
436 "aborting resume\n");
437 return error;
438 }
439
440 error = platform_pre_restore(platform_mode);
441 if (error)
442 goto Cleanup;
443
444 error = hibernate_resume_nonboot_cpu_disable();
445 if (error)
446 goto Enable_cpus;
447
448 local_irq_disable();
449
450 error = syscore_suspend();
451 if (error)
452 goto Enable_irqs;
453
454 save_processor_state();
455 error = restore_highmem();
456 if (!error) {
457 error = swsusp_arch_resume();
458 /*
459 * The code below is only ever reached in case of a failure.
460 * Otherwise, execution continues at the place where
461 * swsusp_arch_suspend() was called.
462 */
463 BUG_ON(!error);
464 /*
465 * This call to restore_highmem() reverts the changes made by
466 * the previous one.
467 */
468 restore_highmem();
469 }
470 /*
471 * The only reason why swsusp_arch_resume() can fail is memory being
472 * very tight, so we have to free it as soon as we can to avoid
473 * subsequent failures.
474 */
475 swsusp_free();
476 restore_processor_state();
477 touch_softlockup_watchdog();
478
479 syscore_resume();
480
481 Enable_irqs:
482 local_irq_enable();
483
484 Enable_cpus:
485 enable_nonboot_cpus();
486
487 Cleanup:
488 platform_restore_cleanup(platform_mode);
489
490 dpm_resume_start(PMSG_RECOVER);
491
492 return error;
493}
494
495/**
496 * hibernation_restore - Quiesce devices and restore from a hibernation image.
497 * @platform_mode: If set, use platform driver to prepare for the transition.
498 *
499 * This routine must be called with pm_mutex held. If it is successful, control
500 * reappears in the restored target kernel in hibernation_snapshot().
501 */
502int hibernation_restore(int platform_mode)
503{
504 int error;
505
506 pm_prepare_console();
507 suspend_console();
508 pm_restrict_gfp_mask();
509 error = dpm_suspend_start(PMSG_QUIESCE);
510 if (!error) {
511 error = resume_target_kernel(platform_mode);
512 /*
513 * The above should either succeed and jump to the new kernel,
514 * or return with an error. Otherwise things are just
515 * undefined, so let's be paranoid.
516 */
517 BUG_ON(!error);
518 }
519 dpm_resume_end(PMSG_RECOVER);
520 pm_restore_gfp_mask();
521 resume_console();
522 pm_restore_console();
523 return error;
524}
525
526/**
527 * hibernation_platform_enter - Power off the system using the platform driver.
528 */
529int hibernation_platform_enter(void)
530{
531 int error;
532
533 if (!hibernation_ops)
534 return -ENOSYS;
535
536 /*
537 * We have cancelled the power transition by running
538 * hibernation_ops->finish() before saving the image, so we should let
539 * the firmware know that we're going to enter the sleep state after all
540 */
541 error = hibernation_ops->begin();
542 if (error)
543 goto Close;
544
545 entering_platform_hibernation = true;
546 suspend_console();
547 error = dpm_suspend_start(PMSG_HIBERNATE);
548 if (error) {
549 if (hibernation_ops->recover)
550 hibernation_ops->recover();
551 goto Resume_devices;
552 }
553
554 error = dpm_suspend_end(PMSG_HIBERNATE);
555 if (error)
556 goto Resume_devices;
557
558 error = hibernation_ops->prepare();
559 if (error)
560 goto Platform_finish;
561
562 error = disable_nonboot_cpus();
563 if (error)
564 goto Enable_cpus;
565
566 local_irq_disable();
567 syscore_suspend();
568 if (pm_wakeup_pending()) {
569 error = -EAGAIN;
570 goto Power_up;
571 }
572
573 hibernation_ops->enter();
574 /* We should never get here */
575 while (1);
576
577 Power_up:
578 syscore_resume();
579 local_irq_enable();
580
581 Enable_cpus:
582 enable_nonboot_cpus();
583
584 Platform_finish:
585 hibernation_ops->finish();
586
587 dpm_resume_start(PMSG_RESTORE);
588
589 Resume_devices:
590 entering_platform_hibernation = false;
591 dpm_resume_end(PMSG_RESTORE);
592 resume_console();
593
594 Close:
595 hibernation_ops->end();
596
597 return error;
598}
599
600/**
601 * power_down - Shut the machine down for hibernation.
602 *
603 * Use the platform driver, if configured, to put the system into the sleep
604 * state corresponding to hibernation, or try to power it off or reboot,
605 * depending on the value of hibernation_mode.
606 */
607static void power_down(void)
608{
609#ifdef CONFIG_SUSPEND
610 int error;
611#endif
612
613 switch (hibernation_mode) {
614 case HIBERNATION_REBOOT:
615 kernel_restart(NULL);
616 break;
617 case HIBERNATION_PLATFORM:
618 hibernation_platform_enter();
619 case HIBERNATION_SHUTDOWN:
620 if (pm_power_off)
621 kernel_power_off();
622 break;
623#ifdef CONFIG_SUSPEND
624 case HIBERNATION_SUSPEND:
625 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
626 if (error) {
627 if (hibernation_ops)
628 hibernation_mode = HIBERNATION_PLATFORM;
629 else
630 hibernation_mode = HIBERNATION_SHUTDOWN;
631 power_down();
632 }
633 /*
634 * Restore swap signature.
635 */
636 error = swsusp_unmark();
637 if (error)
638 printk(KERN_ERR "PM: Swap will be unusable! "
639 "Try swapon -a.\n");
640 return;
641#endif
642 }
643 kernel_halt();
644 /*
645 * Valid image is on the disk, if we continue we risk serious data
646 * corruption after resume.
647 */
648 printk(KERN_CRIT "PM: Please power down manually\n");
649 while (1)
650 cpu_relax();
651}
652
653static int load_image_and_restore(void)
654{
655 int error;
656 unsigned int flags;
657
658 pr_debug("PM: Loading hibernation image.\n");
659
660 lock_device_hotplug();
661 error = create_basic_memory_bitmaps();
662 if (error)
663 goto Unlock;
664
665 error = swsusp_read(&flags);
666 swsusp_close(FMODE_READ);
667 if (!error)
668 hibernation_restore(flags & SF_PLATFORM_MODE);
669
670 printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
671 swsusp_free();
672 free_basic_memory_bitmaps();
673 Unlock:
674 unlock_device_hotplug();
675
676 return error;
677}
678
679/**
680 * hibernate - Carry out system hibernation, including saving the image.
681 */
682int hibernate(void)
683{
684 int error, nr_calls = 0;
685 bool snapshot_test = false;
686
687 if (!hibernation_available()) {
688 pr_debug("PM: Hibernation not available.\n");
689 return -EPERM;
690 }
691
692 lock_system_sleep();
693 /* The snapshot device should not be opened while we're running */
694 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
695 error = -EBUSY;
696 goto Unlock;
697 }
698
699 pm_prepare_console();
700 error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
701 if (error) {
702 nr_calls--;
703 goto Exit;
704 }
705
706 printk(KERN_INFO "PM: Syncing filesystems ... ");
707 sys_sync();
708 printk("done.\n");
709
710 error = freeze_processes();
711 if (error)
712 goto Exit;
713
714 lock_device_hotplug();
715 /* Allocate memory management structures */
716 error = create_basic_memory_bitmaps();
717 if (error)
718 goto Thaw;
719
720 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
721 if (error || freezer_test_done)
722 goto Free_bitmaps;
723
724 if (in_suspend) {
725 unsigned int flags = 0;
726
727 if (hibernation_mode == HIBERNATION_PLATFORM)
728 flags |= SF_PLATFORM_MODE;
729 if (nocompress)
730 flags |= SF_NOCOMPRESS_MODE;
731 else
732 flags |= SF_CRC32_MODE;
733
734 pr_debug("PM: writing image.\n");
735 error = swsusp_write(flags);
736 swsusp_free();
737 if (!error) {
738 if (hibernation_mode == HIBERNATION_TEST_RESUME)
739 snapshot_test = true;
740 else
741 power_down();
742 }
743 in_suspend = 0;
744 pm_restore_gfp_mask();
745 } else {
746 pr_debug("PM: Image restored successfully.\n");
747 }
748
749 Free_bitmaps:
750 free_basic_memory_bitmaps();
751 Thaw:
752 unlock_device_hotplug();
753 if (snapshot_test) {
754 pr_debug("PM: Checking hibernation image\n");
755 error = swsusp_check();
756 if (!error)
757 error = load_image_and_restore();
758 }
759 thaw_processes();
760
761 /* Don't bother checking whether freezer_test_done is true */
762 freezer_test_done = false;
763 Exit:
764 __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
765 pm_restore_console();
766 atomic_inc(&snapshot_device_available);
767 Unlock:
768 unlock_system_sleep();
769 return error;
770}
771
772
773/**
774 * software_resume - Resume from a saved hibernation image.
775 *
776 * This routine is called as a late initcall, when all devices have been
777 * discovered and initialized already.
778 *
779 * The image reading code is called to see if there is a hibernation image
780 * available for reading. If that is the case, devices are quiesced and the
781 * contents of memory is restored from the saved image.
782 *
783 * If this is successful, control reappears in the restored target kernel in
784 * hibernation_snapshot() which returns to hibernate(). Otherwise, the routine
785 * attempts to recover gracefully and make the kernel return to the normal mode
786 * of operation.
787 */
788static int software_resume(void)
789{
790 int error, nr_calls = 0;
791
792 /*
793 * If the user said "noresume".. bail out early.
794 */
795 if (noresume || !hibernation_available())
796 return 0;
797
798 /*
799 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
800 * is configured into the kernel. Since the regular hibernate
801 * trigger path is via sysfs which takes a buffer mutex before
802 * calling hibernate functions (which take pm_mutex) this can
803 * cause lockdep to complain about a possible ABBA deadlock
804 * which cannot happen since we're in the boot code here and
805 * sysfs can't be invoked yet. Therefore, we use a subclass
806 * here to avoid lockdep complaining.
807 */
808 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
809
810 if (swsusp_resume_device)
811 goto Check_image;
812
813 if (!strlen(resume_file)) {
814 error = -ENOENT;
815 goto Unlock;
816 }
817
818 pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
819
820 if (resume_delay) {
821 printk(KERN_INFO "Waiting %dsec before reading resume device...\n",
822 resume_delay);
823 ssleep(resume_delay);
824 }
825
826 /* Check if the device is there */
827 swsusp_resume_device = name_to_dev_t(resume_file);
828
829 /*
830 * name_to_dev_t is ineffective to verify parition if resume_file is in
831 * integer format. (e.g. major:minor)
832 */
833 if (isdigit(resume_file[0]) && resume_wait) {
834 int partno;
835 while (!get_gendisk(swsusp_resume_device, &partno))
836 msleep(10);
837 }
838
839 if (!swsusp_resume_device) {
840 /*
841 * Some device discovery might still be in progress; we need
842 * to wait for this to finish.
843 */
844 wait_for_device_probe();
845
846 if (resume_wait) {
847 while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
848 msleep(10);
849 async_synchronize_full();
850 }
851
852 swsusp_resume_device = name_to_dev_t(resume_file);
853 if (!swsusp_resume_device) {
854 error = -ENODEV;
855 goto Unlock;
856 }
857 }
858
859 Check_image:
860 pr_debug("PM: Hibernation image partition %d:%d present\n",
861 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
862
863 pr_debug("PM: Looking for hibernation image.\n");
864 error = swsusp_check();
865 if (error)
866 goto Unlock;
867
868 /* The snapshot device should not be opened while we're running */
869 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
870 error = -EBUSY;
871 swsusp_close(FMODE_READ);
872 goto Unlock;
873 }
874
875 pm_prepare_console();
876 error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
877 if (error) {
878 nr_calls--;
879 goto Close_Finish;
880 }
881
882 pr_debug("PM: Preparing processes for restore.\n");
883 error = freeze_processes();
884 if (error)
885 goto Close_Finish;
886 error = load_image_and_restore();
887 thaw_processes();
888 Finish:
889 __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
890 pm_restore_console();
891 atomic_inc(&snapshot_device_available);
892 /* For success case, the suspend path will release the lock */
893 Unlock:
894 mutex_unlock(&pm_mutex);
895 pr_debug("PM: Hibernation image not present or could not be loaded.\n");
896 return error;
897 Close_Finish:
898 swsusp_close(FMODE_READ);
899 goto Finish;
900}
901
902late_initcall_sync(software_resume);
903
904
905static const char * const hibernation_modes[] = {
906 [HIBERNATION_PLATFORM] = "platform",
907 [HIBERNATION_SHUTDOWN] = "shutdown",
908 [HIBERNATION_REBOOT] = "reboot",
909#ifdef CONFIG_SUSPEND
910 [HIBERNATION_SUSPEND] = "suspend",
911#endif
912 [HIBERNATION_TEST_RESUME] = "test_resume",
913};
914
915/*
916 * /sys/power/disk - Control hibernation mode.
917 *
918 * Hibernation can be handled in several ways. There are a few different ways
919 * to put the system into the sleep state: using the platform driver (e.g. ACPI
920 * or other hibernation_ops), powering it off or rebooting it (for testing
921 * mostly).
922 *
923 * The sysfs file /sys/power/disk provides an interface for selecting the
924 * hibernation mode to use. Reading from this file causes the available modes
925 * to be printed. There are 3 modes that can be supported:
926 *
927 * 'platform'
928 * 'shutdown'
929 * 'reboot'
930 *
931 * If a platform hibernation driver is in use, 'platform' will be supported
932 * and will be used by default. Otherwise, 'shutdown' will be used by default.
933 * The selected option (i.e. the one corresponding to the current value of
934 * hibernation_mode) is enclosed by a square bracket.
935 *
936 * To select a given hibernation mode it is necessary to write the mode's
937 * string representation (as returned by reading from /sys/power/disk) back
938 * into /sys/power/disk.
939 */
940
941static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
942 char *buf)
943{
944 int i;
945 char *start = buf;
946
947 if (!hibernation_available())
948 return sprintf(buf, "[disabled]\n");
949
950 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
951 if (!hibernation_modes[i])
952 continue;
953 switch (i) {
954 case HIBERNATION_SHUTDOWN:
955 case HIBERNATION_REBOOT:
956#ifdef CONFIG_SUSPEND
957 case HIBERNATION_SUSPEND:
958#endif
959 case HIBERNATION_TEST_RESUME:
960 break;
961 case HIBERNATION_PLATFORM:
962 if (hibernation_ops)
963 break;
964 /* not a valid mode, continue with loop */
965 continue;
966 }
967 if (i == hibernation_mode)
968 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
969 else
970 buf += sprintf(buf, "%s ", hibernation_modes[i]);
971 }
972 buf += sprintf(buf, "\n");
973 return buf-start;
974}
975
976static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
977 const char *buf, size_t n)
978{
979 int error = 0;
980 int i;
981 int len;
982 char *p;
983 int mode = HIBERNATION_INVALID;
984
985 if (!hibernation_available())
986 return -EPERM;
987
988 p = memchr(buf, '\n', n);
989 len = p ? p - buf : n;
990
991 lock_system_sleep();
992 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
993 if (len == strlen(hibernation_modes[i])
994 && !strncmp(buf, hibernation_modes[i], len)) {
995 mode = i;
996 break;
997 }
998 }
999 if (mode != HIBERNATION_INVALID) {
1000 switch (mode) {
1001 case HIBERNATION_SHUTDOWN:
1002 case HIBERNATION_REBOOT:
1003#ifdef CONFIG_SUSPEND
1004 case HIBERNATION_SUSPEND:
1005#endif
1006 case HIBERNATION_TEST_RESUME:
1007 hibernation_mode = mode;
1008 break;
1009 case HIBERNATION_PLATFORM:
1010 if (hibernation_ops)
1011 hibernation_mode = mode;
1012 else
1013 error = -EINVAL;
1014 }
1015 } else
1016 error = -EINVAL;
1017
1018 if (!error)
1019 pr_debug("PM: Hibernation mode set to '%s'\n",
1020 hibernation_modes[mode]);
1021 unlock_system_sleep();
1022 return error ? error : n;
1023}
1024
1025power_attr(disk);
1026
1027static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1028 char *buf)
1029{
1030 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
1031 MINOR(swsusp_resume_device));
1032}
1033
1034static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1035 const char *buf, size_t n)
1036{
1037 dev_t res;
1038 int len = n;
1039 char *name;
1040
1041 if (len && buf[len-1] == '\n')
1042 len--;
1043 name = kstrndup(buf, len, GFP_KERNEL);
1044 if (!name)
1045 return -ENOMEM;
1046
1047 res = name_to_dev_t(name);
1048 kfree(name);
1049 if (!res)
1050 return -EINVAL;
1051
1052 lock_system_sleep();
1053 swsusp_resume_device = res;
1054 unlock_system_sleep();
1055 printk(KERN_INFO "PM: Starting manual resume from disk\n");
1056 noresume = 0;
1057 software_resume();
1058 return n;
1059}
1060
1061power_attr(resume);
1062
1063static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1064 char *buf)
1065{
1066 return sprintf(buf, "%lu\n", image_size);
1067}
1068
1069static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1070 const char *buf, size_t n)
1071{
1072 unsigned long size;
1073
1074 if (sscanf(buf, "%lu", &size) == 1) {
1075 image_size = size;
1076 return n;
1077 }
1078
1079 return -EINVAL;
1080}
1081
1082power_attr(image_size);
1083
1084static ssize_t reserved_size_show(struct kobject *kobj,
1085 struct kobj_attribute *attr, char *buf)
1086{
1087 return sprintf(buf, "%lu\n", reserved_size);
1088}
1089
1090static ssize_t reserved_size_store(struct kobject *kobj,
1091 struct kobj_attribute *attr,
1092 const char *buf, size_t n)
1093{
1094 unsigned long size;
1095
1096 if (sscanf(buf, "%lu", &size) == 1) {
1097 reserved_size = size;
1098 return n;
1099 }
1100
1101 return -EINVAL;
1102}
1103
1104power_attr(reserved_size);
1105
1106static struct attribute * g[] = {
1107 &disk_attr.attr,
1108 &resume_attr.attr,
1109 &image_size_attr.attr,
1110 &reserved_size_attr.attr,
1111 NULL,
1112};
1113
1114
1115static struct attribute_group attr_group = {
1116 .attrs = g,
1117};
1118
1119
1120static int __init pm_disk_init(void)
1121{
1122 return sysfs_create_group(power_kobj, &attr_group);
1123}
1124
1125core_initcall(pm_disk_init);
1126
1127
1128static int __init resume_setup(char *str)
1129{
1130 if (noresume)
1131 return 1;
1132
1133 strncpy( resume_file, str, 255 );
1134 return 1;
1135}
1136
1137static int __init resume_offset_setup(char *str)
1138{
1139 unsigned long long offset;
1140
1141 if (noresume)
1142 return 1;
1143
1144 if (sscanf(str, "%llu", &offset) == 1)
1145 swsusp_resume_block = offset;
1146
1147 return 1;
1148}
1149
1150static int __init hibernate_setup(char *str)
1151{
1152 if (!strncmp(str, "noresume", 8)) {
1153 noresume = 1;
1154 } else if (!strncmp(str, "nocompress", 10)) {
1155 nocompress = 1;
1156 } else if (!strncmp(str, "no", 2)) {
1157 noresume = 1;
1158 nohibernate = 1;
1159 } else if (IS_ENABLED(CONFIG_DEBUG_RODATA)
1160 && !strncmp(str, "protect_image", 13)) {
1161 enable_restore_image_protection();
1162 }
1163 return 1;
1164}
1165
1166static int __init noresume_setup(char *str)
1167{
1168 noresume = 1;
1169 return 1;
1170}
1171
1172static int __init resumewait_setup(char *str)
1173{
1174 resume_wait = 1;
1175 return 1;
1176}
1177
1178static int __init resumedelay_setup(char *str)
1179{
1180 int rc = kstrtouint(str, 0, &resume_delay);
1181
1182 if (rc)
1183 return rc;
1184 return 1;
1185}
1186
1187static int __init nohibernate_setup(char *str)
1188{
1189 noresume = 1;
1190 nohibernate = 1;
1191 return 1;
1192}
1193
1194__setup("noresume", noresume_setup);
1195__setup("resume_offset=", resume_offset_setup);
1196__setup("resume=", resume_setup);
1197__setup("hibernate=", hibernate_setup);
1198__setup("resumewait", resumewait_setup);
1199__setup("resumedelay=", resumedelay_setup);
1200__setup("nohibernate", nohibernate_setup);