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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// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
4 *
5 * Copyright (c) 2003 Patrick Mochel
6 * Copyright (c) 2003 Open Source Development Lab
7 * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
8 * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
9 * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
10 */
11
12#define pr_fmt(fmt) "PM: hibernation: " fmt
13
14#include <linux/export.h>
15#include <linux/suspend.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/nmi.h>
25#include <linux/console.h>
26#include <linux/cpu.h>
27#include <linux/freezer.h>
28#include <linux/gfp.h>
29#include <linux/syscore_ops.h>
30#include <linux/ctype.h>
31#include <linux/genhd.h>
32#include <linux/ktime.h>
33#include <linux/security.h>
34#include <linux/secretmem.h>
35#include <trace/events/power.h>
36
37#include "power.h"
38
39
40static int nocompress;
41static int noresume;
42static int nohibernate;
43static int resume_wait;
44static unsigned int resume_delay;
45static char resume_file[256] = CONFIG_PM_STD_PARTITION;
46dev_t swsusp_resume_device;
47sector_t swsusp_resume_block;
48__visible int in_suspend __nosavedata;
49
50enum {
51 HIBERNATION_INVALID,
52 HIBERNATION_PLATFORM,
53 HIBERNATION_SHUTDOWN,
54 HIBERNATION_REBOOT,
55#ifdef CONFIG_SUSPEND
56 HIBERNATION_SUSPEND,
57#endif
58 HIBERNATION_TEST_RESUME,
59 /* keep last */
60 __HIBERNATION_AFTER_LAST
61};
62#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
63#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
64
65static int hibernation_mode = HIBERNATION_SHUTDOWN;
66
67bool freezer_test_done;
68
69static const struct platform_hibernation_ops *hibernation_ops;
70
71static atomic_t hibernate_atomic = ATOMIC_INIT(1);
72
73bool hibernate_acquire(void)
74{
75 return atomic_add_unless(&hibernate_atomic, -1, 0);
76}
77
78void hibernate_release(void)
79{
80 atomic_inc(&hibernate_atomic);
81}
82
83bool hibernation_available(void)
84{
85 return nohibernate == 0 &&
86 !security_locked_down(LOCKDOWN_HIBERNATION) &&
87 !secretmem_active();
88}
89
90/**
91 * hibernation_set_ops - Set the global hibernate operations.
92 * @ops: Hibernation operations to use in subsequent hibernation transitions.
93 */
94void hibernation_set_ops(const struct platform_hibernation_ops *ops)
95{
96 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
97 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
98 && ops->restore_cleanup && ops->leave)) {
99 WARN_ON(1);
100 return;
101 }
102 lock_system_sleep();
103 hibernation_ops = ops;
104 if (ops)
105 hibernation_mode = HIBERNATION_PLATFORM;
106 else if (hibernation_mode == HIBERNATION_PLATFORM)
107 hibernation_mode = HIBERNATION_SHUTDOWN;
108
109 unlock_system_sleep();
110}
111EXPORT_SYMBOL_GPL(hibernation_set_ops);
112
113static bool entering_platform_hibernation;
114
115bool system_entering_hibernation(void)
116{
117 return entering_platform_hibernation;
118}
119EXPORT_SYMBOL(system_entering_hibernation);
120
121#ifdef CONFIG_PM_DEBUG
122static void hibernation_debug_sleep(void)
123{
124 pr_info("debug: Waiting for 5 seconds.\n");
125 mdelay(5000);
126}
127
128static int hibernation_test(int level)
129{
130 if (pm_test_level == level) {
131 hibernation_debug_sleep();
132 return 1;
133 }
134 return 0;
135}
136#else /* !CONFIG_PM_DEBUG */
137static int hibernation_test(int level) { return 0; }
138#endif /* !CONFIG_PM_DEBUG */
139
140/**
141 * platform_begin - Call platform to start hibernation.
142 * @platform_mode: Whether or not to use the platform driver.
143 */
144static int platform_begin(int platform_mode)
145{
146 return (platform_mode && hibernation_ops) ?
147 hibernation_ops->begin(PMSG_FREEZE) : 0;
148}
149
150/**
151 * platform_end - Call platform to finish transition to the working state.
152 * @platform_mode: Whether or not to use the platform driver.
153 */
154static void platform_end(int platform_mode)
155{
156 if (platform_mode && hibernation_ops)
157 hibernation_ops->end();
158}
159
160/**
161 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
162 * @platform_mode: Whether or not to use the platform driver.
163 *
164 * Use the platform driver to prepare the system for creating a hibernate image,
165 * if so configured, and return an error code if that fails.
166 */
167
168static int platform_pre_snapshot(int platform_mode)
169{
170 return (platform_mode && hibernation_ops) ?
171 hibernation_ops->pre_snapshot() : 0;
172}
173
174/**
175 * platform_leave - Call platform to prepare a transition to the working state.
176 * @platform_mode: Whether or not to use the platform driver.
177 *
178 * Use the platform driver prepare to prepare the machine for switching to the
179 * normal mode of operation.
180 *
181 * This routine is called on one CPU with interrupts disabled.
182 */
183static void platform_leave(int platform_mode)
184{
185 if (platform_mode && hibernation_ops)
186 hibernation_ops->leave();
187}
188
189/**
190 * platform_finish - Call platform to switch the system to the working state.
191 * @platform_mode: Whether or not to use the platform driver.
192 *
193 * Use the platform driver to switch the machine to the normal mode of
194 * operation.
195 *
196 * This routine must be called after platform_prepare().
197 */
198static void platform_finish(int platform_mode)
199{
200 if (platform_mode && hibernation_ops)
201 hibernation_ops->finish();
202}
203
204/**
205 * platform_pre_restore - Prepare for hibernate image restoration.
206 * @platform_mode: Whether or not to use the platform driver.
207 *
208 * Use the platform driver to prepare the system for resume from a hibernation
209 * image.
210 *
211 * If the restore fails after this function has been called,
212 * platform_restore_cleanup() must be called.
213 */
214static int platform_pre_restore(int platform_mode)
215{
216 return (platform_mode && hibernation_ops) ?
217 hibernation_ops->pre_restore() : 0;
218}
219
220/**
221 * platform_restore_cleanup - Switch to the working state after failing restore.
222 * @platform_mode: Whether or not to use the platform driver.
223 *
224 * Use the platform driver to switch the system to the normal mode of operation
225 * after a failing restore.
226 *
227 * If platform_pre_restore() has been called before the failing restore, this
228 * function must be called too, regardless of the result of
229 * platform_pre_restore().
230 */
231static void platform_restore_cleanup(int platform_mode)
232{
233 if (platform_mode && hibernation_ops)
234 hibernation_ops->restore_cleanup();
235}
236
237/**
238 * platform_recover - Recover from a failure to suspend devices.
239 * @platform_mode: Whether or not to use the platform driver.
240 */
241static void platform_recover(int platform_mode)
242{
243 if (platform_mode && hibernation_ops && hibernation_ops->recover)
244 hibernation_ops->recover();
245}
246
247/**
248 * swsusp_show_speed - Print time elapsed between two events during hibernation.
249 * @start: Starting event.
250 * @stop: Final event.
251 * @nr_pages: Number of memory pages processed between @start and @stop.
252 * @msg: Additional diagnostic message to print.
253 */
254void swsusp_show_speed(ktime_t start, ktime_t stop,
255 unsigned nr_pages, char *msg)
256{
257 ktime_t diff;
258 u64 elapsed_centisecs64;
259 unsigned int centisecs;
260 unsigned int k;
261 unsigned int kps;
262
263 diff = ktime_sub(stop, start);
264 elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
265 centisecs = elapsed_centisecs64;
266 if (centisecs == 0)
267 centisecs = 1; /* avoid div-by-zero */
268 k = nr_pages * (PAGE_SIZE / 1024);
269 kps = (k * 100) / centisecs;
270 pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
271 msg, k, centisecs / 100, centisecs % 100, kps / 1000,
272 (kps % 1000) / 10);
273}
274
275__weak int arch_resume_nosmt(void)
276{
277 return 0;
278}
279
280/**
281 * create_image - Create a hibernation image.
282 * @platform_mode: Whether or not to use the platform driver.
283 *
284 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
285 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
286 *
287 * Control reappears in this routine after the subsequent restore.
288 */
289static int create_image(int platform_mode)
290{
291 int error;
292
293 error = dpm_suspend_end(PMSG_FREEZE);
294 if (error) {
295 pr_err("Some devices failed to power down, aborting\n");
296 return error;
297 }
298
299 error = platform_pre_snapshot(platform_mode);
300 if (error || hibernation_test(TEST_PLATFORM))
301 goto Platform_finish;
302
303 error = suspend_disable_secondary_cpus();
304 if (error || hibernation_test(TEST_CPUS))
305 goto Enable_cpus;
306
307 local_irq_disable();
308
309 system_state = SYSTEM_SUSPEND;
310
311 error = syscore_suspend();
312 if (error) {
313 pr_err("Some system devices failed to power down, aborting\n");
314 goto Enable_irqs;
315 }
316
317 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
318 goto Power_up;
319
320 in_suspend = 1;
321 save_processor_state();
322 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
323 error = swsusp_arch_suspend();
324 /* Restore control flow magically appears here */
325 restore_processor_state();
326 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
327 if (error)
328 pr_err("Error %d creating image\n", error);
329
330 if (!in_suspend) {
331 events_check_enabled = false;
332 clear_or_poison_free_pages();
333 }
334
335 platform_leave(platform_mode);
336
337 Power_up:
338 syscore_resume();
339
340 Enable_irqs:
341 system_state = SYSTEM_RUNNING;
342 local_irq_enable();
343
344 Enable_cpus:
345 suspend_enable_secondary_cpus();
346
347 /* Allow architectures to do nosmt-specific post-resume dances */
348 if (!in_suspend)
349 error = arch_resume_nosmt();
350
351 Platform_finish:
352 platform_finish(platform_mode);
353
354 dpm_resume_start(in_suspend ?
355 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
356
357 return error;
358}
359
360/**
361 * hibernation_snapshot - Quiesce devices and create a hibernation image.
362 * @platform_mode: If set, use platform driver to prepare for the transition.
363 *
364 * This routine must be called with system_transition_mutex held.
365 */
366int hibernation_snapshot(int platform_mode)
367{
368 pm_message_t msg;
369 int error;
370
371 pm_suspend_clear_flags();
372 error = platform_begin(platform_mode);
373 if (error)
374 goto Close;
375
376 /* Preallocate image memory before shutting down devices. */
377 error = hibernate_preallocate_memory();
378 if (error)
379 goto Close;
380
381 error = freeze_kernel_threads();
382 if (error)
383 goto Cleanup;
384
385 if (hibernation_test(TEST_FREEZER)) {
386
387 /*
388 * Indicate to the caller that we are returning due to a
389 * successful freezer test.
390 */
391 freezer_test_done = true;
392 goto Thaw;
393 }
394
395 error = dpm_prepare(PMSG_FREEZE);
396 if (error) {
397 dpm_complete(PMSG_RECOVER);
398 goto Thaw;
399 }
400
401 suspend_console();
402 pm_restrict_gfp_mask();
403
404 error = dpm_suspend(PMSG_FREEZE);
405
406 if (error || hibernation_test(TEST_DEVICES))
407 platform_recover(platform_mode);
408 else
409 error = create_image(platform_mode);
410
411 /*
412 * In the case that we call create_image() above, the control
413 * returns here (1) after the image has been created or the
414 * image creation has failed and (2) after a successful restore.
415 */
416
417 /* We may need to release the preallocated image pages here. */
418 if (error || !in_suspend)
419 swsusp_free();
420
421 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
422 dpm_resume(msg);
423
424 if (error || !in_suspend)
425 pm_restore_gfp_mask();
426
427 resume_console();
428 dpm_complete(msg);
429
430 Close:
431 platform_end(platform_mode);
432 return error;
433
434 Thaw:
435 thaw_kernel_threads();
436 Cleanup:
437 swsusp_free();
438 goto Close;
439}
440
441int __weak hibernate_resume_nonboot_cpu_disable(void)
442{
443 return suspend_disable_secondary_cpus();
444}
445
446/**
447 * resume_target_kernel - Restore system state from a hibernation image.
448 * @platform_mode: Whether or not to use the platform driver.
449 *
450 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
451 * contents of highmem that have not been restored yet from the image and run
452 * the low-level code that will restore the remaining contents of memory and
453 * switch to the just restored target kernel.
454 */
455static int resume_target_kernel(bool platform_mode)
456{
457 int error;
458
459 error = dpm_suspend_end(PMSG_QUIESCE);
460 if (error) {
461 pr_err("Some devices failed to power down, aborting resume\n");
462 return error;
463 }
464
465 error = platform_pre_restore(platform_mode);
466 if (error)
467 goto Cleanup;
468
469 error = hibernate_resume_nonboot_cpu_disable();
470 if (error)
471 goto Enable_cpus;
472
473 local_irq_disable();
474 system_state = SYSTEM_SUSPEND;
475
476 error = syscore_suspend();
477 if (error)
478 goto Enable_irqs;
479
480 save_processor_state();
481 error = restore_highmem();
482 if (!error) {
483 error = swsusp_arch_resume();
484 /*
485 * The code below is only ever reached in case of a failure.
486 * Otherwise, execution continues at the place where
487 * swsusp_arch_suspend() was called.
488 */
489 BUG_ON(!error);
490 /*
491 * This call to restore_highmem() reverts the changes made by
492 * the previous one.
493 */
494 restore_highmem();
495 }
496 /*
497 * The only reason why swsusp_arch_resume() can fail is memory being
498 * very tight, so we have to free it as soon as we can to avoid
499 * subsequent failures.
500 */
501 swsusp_free();
502 restore_processor_state();
503 touch_softlockup_watchdog();
504
505 syscore_resume();
506
507 Enable_irqs:
508 system_state = SYSTEM_RUNNING;
509 local_irq_enable();
510
511 Enable_cpus:
512 suspend_enable_secondary_cpus();
513
514 Cleanup:
515 platform_restore_cleanup(platform_mode);
516
517 dpm_resume_start(PMSG_RECOVER);
518
519 return error;
520}
521
522/**
523 * hibernation_restore - Quiesce devices and restore from a hibernation image.
524 * @platform_mode: If set, use platform driver to prepare for the transition.
525 *
526 * This routine must be called with system_transition_mutex held. If it is
527 * successful, control reappears in the restored target kernel in
528 * hibernation_snapshot().
529 */
530int hibernation_restore(int platform_mode)
531{
532 int error;
533
534 pm_prepare_console();
535 suspend_console();
536 pm_restrict_gfp_mask();
537 error = dpm_suspend_start(PMSG_QUIESCE);
538 if (!error) {
539 error = resume_target_kernel(platform_mode);
540 /*
541 * The above should either succeed and jump to the new kernel,
542 * or return with an error. Otherwise things are just
543 * undefined, so let's be paranoid.
544 */
545 BUG_ON(!error);
546 }
547 dpm_resume_end(PMSG_RECOVER);
548 pm_restore_gfp_mask();
549 resume_console();
550 pm_restore_console();
551 return error;
552}
553
554/**
555 * hibernation_platform_enter - Power off the system using the platform driver.
556 */
557int hibernation_platform_enter(void)
558{
559 int error;
560
561 if (!hibernation_ops)
562 return -ENOSYS;
563
564 /*
565 * We have cancelled the power transition by running
566 * hibernation_ops->finish() before saving the image, so we should let
567 * the firmware know that we're going to enter the sleep state after all
568 */
569 error = hibernation_ops->begin(PMSG_HIBERNATE);
570 if (error)
571 goto Close;
572
573 entering_platform_hibernation = true;
574 suspend_console();
575 error = dpm_suspend_start(PMSG_HIBERNATE);
576 if (error) {
577 if (hibernation_ops->recover)
578 hibernation_ops->recover();
579 goto Resume_devices;
580 }
581
582 error = dpm_suspend_end(PMSG_HIBERNATE);
583 if (error)
584 goto Resume_devices;
585
586 error = hibernation_ops->prepare();
587 if (error)
588 goto Platform_finish;
589
590 error = suspend_disable_secondary_cpus();
591 if (error)
592 goto Enable_cpus;
593
594 local_irq_disable();
595 system_state = SYSTEM_SUSPEND;
596 syscore_suspend();
597 if (pm_wakeup_pending()) {
598 error = -EAGAIN;
599 goto Power_up;
600 }
601
602 hibernation_ops->enter();
603 /* We should never get here */
604 while (1);
605
606 Power_up:
607 syscore_resume();
608 system_state = SYSTEM_RUNNING;
609 local_irq_enable();
610
611 Enable_cpus:
612 suspend_enable_secondary_cpus();
613
614 Platform_finish:
615 hibernation_ops->finish();
616
617 dpm_resume_start(PMSG_RESTORE);
618
619 Resume_devices:
620 entering_platform_hibernation = false;
621 dpm_resume_end(PMSG_RESTORE);
622 resume_console();
623
624 Close:
625 hibernation_ops->end();
626
627 return error;
628}
629
630/**
631 * power_down - Shut the machine down for hibernation.
632 *
633 * Use the platform driver, if configured, to put the system into the sleep
634 * state corresponding to hibernation, or try to power it off or reboot,
635 * depending on the value of hibernation_mode.
636 */
637static void power_down(void)
638{
639#ifdef CONFIG_SUSPEND
640 int error;
641
642 if (hibernation_mode == HIBERNATION_SUSPEND) {
643 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
644 if (error) {
645 hibernation_mode = hibernation_ops ?
646 HIBERNATION_PLATFORM :
647 HIBERNATION_SHUTDOWN;
648 } else {
649 /* Restore swap signature. */
650 error = swsusp_unmark();
651 if (error)
652 pr_err("Swap will be unusable! Try swapon -a.\n");
653
654 return;
655 }
656 }
657#endif
658
659 switch (hibernation_mode) {
660 case HIBERNATION_REBOOT:
661 kernel_restart(NULL);
662 break;
663 case HIBERNATION_PLATFORM:
664 hibernation_platform_enter();
665 fallthrough;
666 case HIBERNATION_SHUTDOWN:
667 if (pm_power_off)
668 kernel_power_off();
669 break;
670 }
671 kernel_halt();
672 /*
673 * Valid image is on the disk, if we continue we risk serious data
674 * corruption after resume.
675 */
676 pr_crit("Power down manually\n");
677 while (1)
678 cpu_relax();
679}
680
681static int load_image_and_restore(void)
682{
683 int error;
684 unsigned int flags;
685
686 pm_pr_dbg("Loading hibernation image.\n");
687
688 lock_device_hotplug();
689 error = create_basic_memory_bitmaps();
690 if (error)
691 goto Unlock;
692
693 error = swsusp_read(&flags);
694 swsusp_close(FMODE_READ);
695 if (!error)
696 error = hibernation_restore(flags & SF_PLATFORM_MODE);
697
698 pr_err("Failed to load image, recovering.\n");
699 swsusp_free();
700 free_basic_memory_bitmaps();
701 Unlock:
702 unlock_device_hotplug();
703
704 return error;
705}
706
707/**
708 * hibernate - Carry out system hibernation, including saving the image.
709 */
710int hibernate(void)
711{
712 bool snapshot_test = false;
713 int error;
714
715 if (!hibernation_available()) {
716 pm_pr_dbg("Hibernation not available.\n");
717 return -EPERM;
718 }
719
720 lock_system_sleep();
721 /* The snapshot device should not be opened while we're running */
722 if (!hibernate_acquire()) {
723 error = -EBUSY;
724 goto Unlock;
725 }
726
727 pr_info("hibernation entry\n");
728 pm_prepare_console();
729 error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
730 if (error)
731 goto Restore;
732
733 ksys_sync_helper();
734
735 error = freeze_processes();
736 if (error)
737 goto Exit;
738
739 lock_device_hotplug();
740 /* Allocate memory management structures */
741 error = create_basic_memory_bitmaps();
742 if (error)
743 goto Thaw;
744
745 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
746 if (error || freezer_test_done)
747 goto Free_bitmaps;
748
749 if (in_suspend) {
750 unsigned int flags = 0;
751
752 if (hibernation_mode == HIBERNATION_PLATFORM)
753 flags |= SF_PLATFORM_MODE;
754 if (nocompress)
755 flags |= SF_NOCOMPRESS_MODE;
756 else
757 flags |= SF_CRC32_MODE;
758
759 pm_pr_dbg("Writing hibernation image.\n");
760 error = swsusp_write(flags);
761 swsusp_free();
762 if (!error) {
763 if (hibernation_mode == HIBERNATION_TEST_RESUME)
764 snapshot_test = true;
765 else
766 power_down();
767 }
768 in_suspend = 0;
769 pm_restore_gfp_mask();
770 } else {
771 pm_pr_dbg("Hibernation image restored successfully.\n");
772 }
773
774 Free_bitmaps:
775 free_basic_memory_bitmaps();
776 Thaw:
777 unlock_device_hotplug();
778 if (snapshot_test) {
779 pm_pr_dbg("Checking hibernation image\n");
780 error = swsusp_check();
781 if (!error)
782 error = load_image_and_restore();
783 }
784 thaw_processes();
785
786 /* Don't bother checking whether freezer_test_done is true */
787 freezer_test_done = false;
788 Exit:
789 pm_notifier_call_chain(PM_POST_HIBERNATION);
790 Restore:
791 pm_restore_console();
792 hibernate_release();
793 Unlock:
794 unlock_system_sleep();
795 pr_info("hibernation exit\n");
796
797 return error;
798}
799
800/**
801 * hibernate_quiet_exec - Execute a function with all devices frozen.
802 * @func: Function to execute.
803 * @data: Data pointer to pass to @func.
804 *
805 * Return the @func return value or an error code if it cannot be executed.
806 */
807int hibernate_quiet_exec(int (*func)(void *data), void *data)
808{
809 int error;
810
811 lock_system_sleep();
812
813 if (!hibernate_acquire()) {
814 error = -EBUSY;
815 goto unlock;
816 }
817
818 pm_prepare_console();
819
820 error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
821 if (error)
822 goto restore;
823
824 error = freeze_processes();
825 if (error)
826 goto exit;
827
828 lock_device_hotplug();
829
830 pm_suspend_clear_flags();
831
832 error = platform_begin(true);
833 if (error)
834 goto thaw;
835
836 error = freeze_kernel_threads();
837 if (error)
838 goto thaw;
839
840 error = dpm_prepare(PMSG_FREEZE);
841 if (error)
842 goto dpm_complete;
843
844 suspend_console();
845
846 error = dpm_suspend(PMSG_FREEZE);
847 if (error)
848 goto dpm_resume;
849
850 error = dpm_suspend_end(PMSG_FREEZE);
851 if (error)
852 goto dpm_resume;
853
854 error = platform_pre_snapshot(true);
855 if (error)
856 goto skip;
857
858 error = func(data);
859
860skip:
861 platform_finish(true);
862
863 dpm_resume_start(PMSG_THAW);
864
865dpm_resume:
866 dpm_resume(PMSG_THAW);
867
868 resume_console();
869
870dpm_complete:
871 dpm_complete(PMSG_THAW);
872
873 thaw_kernel_threads();
874
875thaw:
876 platform_end(true);
877
878 unlock_device_hotplug();
879
880 thaw_processes();
881
882exit:
883 pm_notifier_call_chain(PM_POST_HIBERNATION);
884
885restore:
886 pm_restore_console();
887
888 hibernate_release();
889
890unlock:
891 unlock_system_sleep();
892
893 return error;
894}
895EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
896
897/**
898 * software_resume - Resume from a saved hibernation image.
899 *
900 * This routine is called as a late initcall, when all devices have been
901 * discovered and initialized already.
902 *
903 * The image reading code is called to see if there is a hibernation image
904 * available for reading. If that is the case, devices are quiesced and the
905 * contents of memory is restored from the saved image.
906 *
907 * If this is successful, control reappears in the restored target kernel in
908 * hibernation_snapshot() which returns to hibernate(). Otherwise, the routine
909 * attempts to recover gracefully and make the kernel return to the normal mode
910 * of operation.
911 */
912static int software_resume(void)
913{
914 int error;
915
916 /*
917 * If the user said "noresume".. bail out early.
918 */
919 if (noresume || !hibernation_available())
920 return 0;
921
922 /*
923 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
924 * is configured into the kernel. Since the regular hibernate
925 * trigger path is via sysfs which takes a buffer mutex before
926 * calling hibernate functions (which take system_transition_mutex)
927 * this can cause lockdep to complain about a possible ABBA deadlock
928 * which cannot happen since we're in the boot code here and
929 * sysfs can't be invoked yet. Therefore, we use a subclass
930 * here to avoid lockdep complaining.
931 */
932 mutex_lock_nested(&system_transition_mutex, SINGLE_DEPTH_NESTING);
933
934 if (swsusp_resume_device)
935 goto Check_image;
936
937 if (!strlen(resume_file)) {
938 error = -ENOENT;
939 goto Unlock;
940 }
941
942 pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
943
944 if (resume_delay) {
945 pr_info("Waiting %dsec before reading resume device ...\n",
946 resume_delay);
947 ssleep(resume_delay);
948 }
949
950 /* Check if the device is there */
951 swsusp_resume_device = name_to_dev_t(resume_file);
952 if (!swsusp_resume_device) {
953 /*
954 * Some device discovery might still be in progress; we need
955 * to wait for this to finish.
956 */
957 wait_for_device_probe();
958
959 if (resume_wait) {
960 while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
961 msleep(10);
962 async_synchronize_full();
963 }
964
965 swsusp_resume_device = name_to_dev_t(resume_file);
966 if (!swsusp_resume_device) {
967 error = -ENODEV;
968 goto Unlock;
969 }
970 }
971
972 Check_image:
973 pm_pr_dbg("Hibernation image partition %d:%d present\n",
974 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
975
976 pm_pr_dbg("Looking for hibernation image.\n");
977 error = swsusp_check();
978 if (error)
979 goto Unlock;
980
981 /* The snapshot device should not be opened while we're running */
982 if (!hibernate_acquire()) {
983 error = -EBUSY;
984 swsusp_close(FMODE_READ);
985 goto Unlock;
986 }
987
988 pr_info("resume from hibernation\n");
989 pm_prepare_console();
990 error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
991 if (error)
992 goto Restore;
993
994 pm_pr_dbg("Preparing processes for hibernation restore.\n");
995 error = freeze_processes();
996 if (error)
997 goto Close_Finish;
998
999 error = freeze_kernel_threads();
1000 if (error) {
1001 thaw_processes();
1002 goto Close_Finish;
1003 }
1004
1005 error = load_image_and_restore();
1006 thaw_processes();
1007 Finish:
1008 pm_notifier_call_chain(PM_POST_RESTORE);
1009 Restore:
1010 pm_restore_console();
1011 pr_info("resume failed (%d)\n", error);
1012 hibernate_release();
1013 /* For success case, the suspend path will release the lock */
1014 Unlock:
1015 mutex_unlock(&system_transition_mutex);
1016 pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
1017 return error;
1018 Close_Finish:
1019 swsusp_close(FMODE_READ);
1020 goto Finish;
1021}
1022
1023late_initcall_sync(software_resume);
1024
1025
1026static const char * const hibernation_modes[] = {
1027 [HIBERNATION_PLATFORM] = "platform",
1028 [HIBERNATION_SHUTDOWN] = "shutdown",
1029 [HIBERNATION_REBOOT] = "reboot",
1030#ifdef CONFIG_SUSPEND
1031 [HIBERNATION_SUSPEND] = "suspend",
1032#endif
1033 [HIBERNATION_TEST_RESUME] = "test_resume",
1034};
1035
1036/*
1037 * /sys/power/disk - Control hibernation mode.
1038 *
1039 * Hibernation can be handled in several ways. There are a few different ways
1040 * to put the system into the sleep state: using the platform driver (e.g. ACPI
1041 * or other hibernation_ops), powering it off or rebooting it (for testing
1042 * mostly).
1043 *
1044 * The sysfs file /sys/power/disk provides an interface for selecting the
1045 * hibernation mode to use. Reading from this file causes the available modes
1046 * to be printed. There are 3 modes that can be supported:
1047 *
1048 * 'platform'
1049 * 'shutdown'
1050 * 'reboot'
1051 *
1052 * If a platform hibernation driver is in use, 'platform' will be supported
1053 * and will be used by default. Otherwise, 'shutdown' will be used by default.
1054 * The selected option (i.e. the one corresponding to the current value of
1055 * hibernation_mode) is enclosed by a square bracket.
1056 *
1057 * To select a given hibernation mode it is necessary to write the mode's
1058 * string representation (as returned by reading from /sys/power/disk) back
1059 * into /sys/power/disk.
1060 */
1061
1062static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1063 char *buf)
1064{
1065 int i;
1066 char *start = buf;
1067
1068 if (!hibernation_available())
1069 return sprintf(buf, "[disabled]\n");
1070
1071 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1072 if (!hibernation_modes[i])
1073 continue;
1074 switch (i) {
1075 case HIBERNATION_SHUTDOWN:
1076 case HIBERNATION_REBOOT:
1077#ifdef CONFIG_SUSPEND
1078 case HIBERNATION_SUSPEND:
1079#endif
1080 case HIBERNATION_TEST_RESUME:
1081 break;
1082 case HIBERNATION_PLATFORM:
1083 if (hibernation_ops)
1084 break;
1085 /* not a valid mode, continue with loop */
1086 continue;
1087 }
1088 if (i == hibernation_mode)
1089 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
1090 else
1091 buf += sprintf(buf, "%s ", hibernation_modes[i]);
1092 }
1093 buf += sprintf(buf, "\n");
1094 return buf-start;
1095}
1096
1097static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1098 const char *buf, size_t n)
1099{
1100 int error = 0;
1101 int i;
1102 int len;
1103 char *p;
1104 int mode = HIBERNATION_INVALID;
1105
1106 if (!hibernation_available())
1107 return -EPERM;
1108
1109 p = memchr(buf, '\n', n);
1110 len = p ? p - buf : n;
1111
1112 lock_system_sleep();
1113 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1114 if (len == strlen(hibernation_modes[i])
1115 && !strncmp(buf, hibernation_modes[i], len)) {
1116 mode = i;
1117 break;
1118 }
1119 }
1120 if (mode != HIBERNATION_INVALID) {
1121 switch (mode) {
1122 case HIBERNATION_SHUTDOWN:
1123 case HIBERNATION_REBOOT:
1124#ifdef CONFIG_SUSPEND
1125 case HIBERNATION_SUSPEND:
1126#endif
1127 case HIBERNATION_TEST_RESUME:
1128 hibernation_mode = mode;
1129 break;
1130 case HIBERNATION_PLATFORM:
1131 if (hibernation_ops)
1132 hibernation_mode = mode;
1133 else
1134 error = -EINVAL;
1135 }
1136 } else
1137 error = -EINVAL;
1138
1139 if (!error)
1140 pm_pr_dbg("Hibernation mode set to '%s'\n",
1141 hibernation_modes[mode]);
1142 unlock_system_sleep();
1143 return error ? error : n;
1144}
1145
1146power_attr(disk);
1147
1148static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1149 char *buf)
1150{
1151 return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1152 MINOR(swsusp_resume_device));
1153}
1154
1155static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1156 const char *buf, size_t n)
1157{
1158 dev_t res;
1159 int len = n;
1160 char *name;
1161
1162 if (len && buf[len-1] == '\n')
1163 len--;
1164 name = kstrndup(buf, len, GFP_KERNEL);
1165 if (!name)
1166 return -ENOMEM;
1167
1168 res = name_to_dev_t(name);
1169 kfree(name);
1170 if (!res)
1171 return -EINVAL;
1172
1173 lock_system_sleep();
1174 swsusp_resume_device = res;
1175 unlock_system_sleep();
1176 pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1177 swsusp_resume_device);
1178 noresume = 0;
1179 software_resume();
1180 return n;
1181}
1182
1183power_attr(resume);
1184
1185static ssize_t resume_offset_show(struct kobject *kobj,
1186 struct kobj_attribute *attr, char *buf)
1187{
1188 return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1189}
1190
1191static ssize_t resume_offset_store(struct kobject *kobj,
1192 struct kobj_attribute *attr, const char *buf,
1193 size_t n)
1194{
1195 unsigned long long offset;
1196 int rc;
1197
1198 rc = kstrtoull(buf, 0, &offset);
1199 if (rc)
1200 return rc;
1201 swsusp_resume_block = offset;
1202
1203 return n;
1204}
1205
1206power_attr(resume_offset);
1207
1208static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1209 char *buf)
1210{
1211 return sprintf(buf, "%lu\n", image_size);
1212}
1213
1214static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1215 const char *buf, size_t n)
1216{
1217 unsigned long size;
1218
1219 if (sscanf(buf, "%lu", &size) == 1) {
1220 image_size = size;
1221 return n;
1222 }
1223
1224 return -EINVAL;
1225}
1226
1227power_attr(image_size);
1228
1229static ssize_t reserved_size_show(struct kobject *kobj,
1230 struct kobj_attribute *attr, char *buf)
1231{
1232 return sprintf(buf, "%lu\n", reserved_size);
1233}
1234
1235static ssize_t reserved_size_store(struct kobject *kobj,
1236 struct kobj_attribute *attr,
1237 const char *buf, size_t n)
1238{
1239 unsigned long size;
1240
1241 if (sscanf(buf, "%lu", &size) == 1) {
1242 reserved_size = size;
1243 return n;
1244 }
1245
1246 return -EINVAL;
1247}
1248
1249power_attr(reserved_size);
1250
1251static struct attribute *g[] = {
1252 &disk_attr.attr,
1253 &resume_offset_attr.attr,
1254 &resume_attr.attr,
1255 &image_size_attr.attr,
1256 &reserved_size_attr.attr,
1257 NULL,
1258};
1259
1260
1261static const struct attribute_group attr_group = {
1262 .attrs = g,
1263};
1264
1265
1266static int __init pm_disk_init(void)
1267{
1268 return sysfs_create_group(power_kobj, &attr_group);
1269}
1270
1271core_initcall(pm_disk_init);
1272
1273
1274static int __init resume_setup(char *str)
1275{
1276 if (noresume)
1277 return 1;
1278
1279 strncpy(resume_file, str, 255);
1280 return 1;
1281}
1282
1283static int __init resume_offset_setup(char *str)
1284{
1285 unsigned long long offset;
1286
1287 if (noresume)
1288 return 1;
1289
1290 if (sscanf(str, "%llu", &offset) == 1)
1291 swsusp_resume_block = offset;
1292
1293 return 1;
1294}
1295
1296static int __init hibernate_setup(char *str)
1297{
1298 if (!strncmp(str, "noresume", 8)) {
1299 noresume = 1;
1300 } else if (!strncmp(str, "nocompress", 10)) {
1301 nocompress = 1;
1302 } else if (!strncmp(str, "no", 2)) {
1303 noresume = 1;
1304 nohibernate = 1;
1305 } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1306 && !strncmp(str, "protect_image", 13)) {
1307 enable_restore_image_protection();
1308 }
1309 return 1;
1310}
1311
1312static int __init noresume_setup(char *str)
1313{
1314 noresume = 1;
1315 return 1;
1316}
1317
1318static int __init resumewait_setup(char *str)
1319{
1320 resume_wait = 1;
1321 return 1;
1322}
1323
1324static int __init resumedelay_setup(char *str)
1325{
1326 int rc = kstrtouint(str, 0, &resume_delay);
1327
1328 if (rc)
1329 return rc;
1330 return 1;
1331}
1332
1333static int __init nohibernate_setup(char *str)
1334{
1335 noresume = 1;
1336 nohibernate = 1;
1337 return 1;
1338}
1339
1340__setup("noresume", noresume_setup);
1341__setup("resume_offset=", resume_offset_setup);
1342__setup("resume=", resume_setup);
1343__setup("hibernate=", hibernate_setup);
1344__setup("resumewait", resumewait_setup);
1345__setup("resumedelay=", resumedelay_setup);
1346__setup("nohibernate", nohibernate_setup);