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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/blkdev.h>
15#include <linux/export.h>
16#include <linux/suspend.h>
17#include <linux/reboot.h>
18#include <linux/string.h>
19#include <linux/device.h>
20#include <linux/async.h>
21#include <linux/delay.h>
22#include <linux/fs.h>
23#include <linux/mount.h>
24#include <linux/pm.h>
25#include <linux/nmi.h>
26#include <linux/console.h>
27#include <linux/cpu.h>
28#include <linux/freezer.h>
29#include <linux/gfp.h>
30#include <linux/syscore_ops.h>
31#include <linux/ctype.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() && !cxl_mem_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 unsigned int sleep_flags;
97
98 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
99 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
100 && ops->restore_cleanup && ops->leave)) {
101 WARN_ON(1);
102 return;
103 }
104
105 sleep_flags = lock_system_sleep();
106
107 hibernation_ops = ops;
108 if (ops)
109 hibernation_mode = HIBERNATION_PLATFORM;
110 else if (hibernation_mode == HIBERNATION_PLATFORM)
111 hibernation_mode = HIBERNATION_SHUTDOWN;
112
113 unlock_system_sleep(sleep_flags);
114}
115EXPORT_SYMBOL_GPL(hibernation_set_ops);
116
117static bool entering_platform_hibernation;
118
119bool system_entering_hibernation(void)
120{
121 return entering_platform_hibernation;
122}
123EXPORT_SYMBOL(system_entering_hibernation);
124
125#ifdef CONFIG_PM_DEBUG
126static void hibernation_debug_sleep(void)
127{
128 pr_info("debug: Waiting for 5 seconds.\n");
129 mdelay(5000);
130}
131
132static int hibernation_test(int level)
133{
134 if (pm_test_level == level) {
135 hibernation_debug_sleep();
136 return 1;
137 }
138 return 0;
139}
140#else /* !CONFIG_PM_DEBUG */
141static int hibernation_test(int level) { return 0; }
142#endif /* !CONFIG_PM_DEBUG */
143
144/**
145 * platform_begin - Call platform to start hibernation.
146 * @platform_mode: Whether or not to use the platform driver.
147 */
148static int platform_begin(int platform_mode)
149{
150 return (platform_mode && hibernation_ops) ?
151 hibernation_ops->begin(PMSG_FREEZE) : 0;
152}
153
154/**
155 * platform_end - Call platform to finish transition to the working state.
156 * @platform_mode: Whether or not to use the platform driver.
157 */
158static void platform_end(int platform_mode)
159{
160 if (platform_mode && hibernation_ops)
161 hibernation_ops->end();
162}
163
164/**
165 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
166 * @platform_mode: Whether or not to use the platform driver.
167 *
168 * Use the platform driver to prepare the system for creating a hibernate image,
169 * if so configured, and return an error code if that fails.
170 */
171
172static int platform_pre_snapshot(int platform_mode)
173{
174 return (platform_mode && hibernation_ops) ?
175 hibernation_ops->pre_snapshot() : 0;
176}
177
178/**
179 * platform_leave - Call platform to prepare a transition to the working state.
180 * @platform_mode: Whether or not to use the platform driver.
181 *
182 * Use the platform driver prepare to prepare the machine for switching to the
183 * normal mode of operation.
184 *
185 * This routine is called on one CPU with interrupts disabled.
186 */
187static void platform_leave(int platform_mode)
188{
189 if (platform_mode && hibernation_ops)
190 hibernation_ops->leave();
191}
192
193/**
194 * platform_finish - Call platform to switch the system to the working state.
195 * @platform_mode: Whether or not to use the platform driver.
196 *
197 * Use the platform driver to switch the machine to the normal mode of
198 * operation.
199 *
200 * This routine must be called after platform_prepare().
201 */
202static void platform_finish(int platform_mode)
203{
204 if (platform_mode && hibernation_ops)
205 hibernation_ops->finish();
206}
207
208/**
209 * platform_pre_restore - Prepare for hibernate image restoration.
210 * @platform_mode: Whether or not to use the platform driver.
211 *
212 * Use the platform driver to prepare the system for resume from a hibernation
213 * image.
214 *
215 * If the restore fails after this function has been called,
216 * platform_restore_cleanup() must be called.
217 */
218static int platform_pre_restore(int platform_mode)
219{
220 return (platform_mode && hibernation_ops) ?
221 hibernation_ops->pre_restore() : 0;
222}
223
224/**
225 * platform_restore_cleanup - Switch to the working state after failing restore.
226 * @platform_mode: Whether or not to use the platform driver.
227 *
228 * Use the platform driver to switch the system to the normal mode of operation
229 * after a failing restore.
230 *
231 * If platform_pre_restore() has been called before the failing restore, this
232 * function must be called too, regardless of the result of
233 * platform_pre_restore().
234 */
235static void platform_restore_cleanup(int platform_mode)
236{
237 if (platform_mode && hibernation_ops)
238 hibernation_ops->restore_cleanup();
239}
240
241/**
242 * platform_recover - Recover from a failure to suspend devices.
243 * @platform_mode: Whether or not to use the platform driver.
244 */
245static void platform_recover(int platform_mode)
246{
247 if (platform_mode && hibernation_ops && hibernation_ops->recover)
248 hibernation_ops->recover();
249}
250
251/**
252 * swsusp_show_speed - Print time elapsed between two events during hibernation.
253 * @start: Starting event.
254 * @stop: Final event.
255 * @nr_pages: Number of memory pages processed between @start and @stop.
256 * @msg: Additional diagnostic message to print.
257 */
258void swsusp_show_speed(ktime_t start, ktime_t stop,
259 unsigned nr_pages, char *msg)
260{
261 ktime_t diff;
262 u64 elapsed_centisecs64;
263 unsigned int centisecs;
264 unsigned int k;
265 unsigned int kps;
266
267 diff = ktime_sub(stop, start);
268 elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
269 centisecs = elapsed_centisecs64;
270 if (centisecs == 0)
271 centisecs = 1; /* avoid div-by-zero */
272 k = nr_pages * (PAGE_SIZE / 1024);
273 kps = (k * 100) / centisecs;
274 pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
275 msg, k, centisecs / 100, centisecs % 100, kps / 1000,
276 (kps % 1000) / 10);
277}
278
279__weak int arch_resume_nosmt(void)
280{
281 return 0;
282}
283
284/**
285 * create_image - Create a hibernation image.
286 * @platform_mode: Whether or not to use the platform driver.
287 *
288 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
289 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
290 *
291 * Control reappears in this routine after the subsequent restore.
292 */
293static int create_image(int platform_mode)
294{
295 int error;
296
297 error = dpm_suspend_end(PMSG_FREEZE);
298 if (error) {
299 pr_err("Some devices failed to power down, aborting\n");
300 return error;
301 }
302
303 error = platform_pre_snapshot(platform_mode);
304 if (error || hibernation_test(TEST_PLATFORM))
305 goto Platform_finish;
306
307 error = pm_sleep_disable_secondary_cpus();
308 if (error || hibernation_test(TEST_CPUS))
309 goto Enable_cpus;
310
311 local_irq_disable();
312
313 system_state = SYSTEM_SUSPEND;
314
315 error = syscore_suspend();
316 if (error) {
317 pr_err("Some system devices failed to power down, aborting\n");
318 goto Enable_irqs;
319 }
320
321 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
322 goto Power_up;
323
324 in_suspend = 1;
325 save_processor_state();
326 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
327 error = swsusp_arch_suspend();
328 /* Restore control flow magically appears here */
329 restore_processor_state();
330 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
331 if (error)
332 pr_err("Error %d creating image\n", error);
333
334 if (!in_suspend) {
335 events_check_enabled = false;
336 clear_or_poison_free_pages();
337 }
338
339 platform_leave(platform_mode);
340
341 Power_up:
342 syscore_resume();
343
344 Enable_irqs:
345 system_state = SYSTEM_RUNNING;
346 local_irq_enable();
347
348 Enable_cpus:
349 pm_sleep_enable_secondary_cpus();
350
351 /* Allow architectures to do nosmt-specific post-resume dances */
352 if (!in_suspend)
353 error = arch_resume_nosmt();
354
355 Platform_finish:
356 platform_finish(platform_mode);
357
358 dpm_resume_start(in_suspend ?
359 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
360
361 return error;
362}
363
364/**
365 * hibernation_snapshot - Quiesce devices and create a hibernation image.
366 * @platform_mode: If set, use platform driver to prepare for the transition.
367 *
368 * This routine must be called with system_transition_mutex held.
369 */
370int hibernation_snapshot(int platform_mode)
371{
372 pm_message_t msg;
373 int error;
374
375 pm_suspend_clear_flags();
376 error = platform_begin(platform_mode);
377 if (error)
378 goto Close;
379
380 /* Preallocate image memory before shutting down devices. */
381 error = hibernate_preallocate_memory();
382 if (error)
383 goto Close;
384
385 error = freeze_kernel_threads();
386 if (error)
387 goto Cleanup;
388
389 if (hibernation_test(TEST_FREEZER)) {
390
391 /*
392 * Indicate to the caller that we are returning due to a
393 * successful freezer test.
394 */
395 freezer_test_done = true;
396 goto Thaw;
397 }
398
399 error = dpm_prepare(PMSG_FREEZE);
400 if (error) {
401 dpm_complete(PMSG_RECOVER);
402 goto Thaw;
403 }
404
405 suspend_console();
406 pm_restrict_gfp_mask();
407
408 error = dpm_suspend(PMSG_FREEZE);
409
410 if (error || hibernation_test(TEST_DEVICES))
411 platform_recover(platform_mode);
412 else
413 error = create_image(platform_mode);
414
415 /*
416 * In the case that we call create_image() above, the control
417 * returns here (1) after the image has been created or the
418 * image creation has failed and (2) after a successful restore.
419 */
420
421 /* We may need to release the preallocated image pages here. */
422 if (error || !in_suspend)
423 swsusp_free();
424
425 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
426 dpm_resume(msg);
427
428 if (error || !in_suspend)
429 pm_restore_gfp_mask();
430
431 resume_console();
432 dpm_complete(msg);
433
434 Close:
435 platform_end(platform_mode);
436 return error;
437
438 Thaw:
439 thaw_kernel_threads();
440 Cleanup:
441 swsusp_free();
442 goto Close;
443}
444
445int __weak hibernate_resume_nonboot_cpu_disable(void)
446{
447 return suspend_disable_secondary_cpus();
448}
449
450/**
451 * resume_target_kernel - Restore system state from a hibernation image.
452 * @platform_mode: Whether or not to use the platform driver.
453 *
454 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
455 * contents of highmem that have not been restored yet from the image and run
456 * the low-level code that will restore the remaining contents of memory and
457 * switch to the just restored target kernel.
458 */
459static int resume_target_kernel(bool platform_mode)
460{
461 int error;
462
463 error = dpm_suspend_end(PMSG_QUIESCE);
464 if (error) {
465 pr_err("Some devices failed to power down, aborting resume\n");
466 return error;
467 }
468
469 error = platform_pre_restore(platform_mode);
470 if (error)
471 goto Cleanup;
472
473 cpuidle_pause();
474
475 error = hibernate_resume_nonboot_cpu_disable();
476 if (error)
477 goto Enable_cpus;
478
479 local_irq_disable();
480 system_state = SYSTEM_SUSPEND;
481
482 error = syscore_suspend();
483 if (error)
484 goto Enable_irqs;
485
486 save_processor_state();
487 error = restore_highmem();
488 if (!error) {
489 error = swsusp_arch_resume();
490 /*
491 * The code below is only ever reached in case of a failure.
492 * Otherwise, execution continues at the place where
493 * swsusp_arch_suspend() was called.
494 */
495 BUG_ON(!error);
496 /*
497 * This call to restore_highmem() reverts the changes made by
498 * the previous one.
499 */
500 restore_highmem();
501 }
502 /*
503 * The only reason why swsusp_arch_resume() can fail is memory being
504 * very tight, so we have to free it as soon as we can to avoid
505 * subsequent failures.
506 */
507 swsusp_free();
508 restore_processor_state();
509 touch_softlockup_watchdog();
510
511 syscore_resume();
512
513 Enable_irqs:
514 system_state = SYSTEM_RUNNING;
515 local_irq_enable();
516
517 Enable_cpus:
518 pm_sleep_enable_secondary_cpus();
519
520 Cleanup:
521 platform_restore_cleanup(platform_mode);
522
523 dpm_resume_start(PMSG_RECOVER);
524
525 return error;
526}
527
528/**
529 * hibernation_restore - Quiesce devices and restore from a hibernation image.
530 * @platform_mode: If set, use platform driver to prepare for the transition.
531 *
532 * This routine must be called with system_transition_mutex held. If it is
533 * successful, control reappears in the restored target kernel in
534 * hibernation_snapshot().
535 */
536int hibernation_restore(int platform_mode)
537{
538 int error;
539
540 pm_prepare_console();
541 suspend_console();
542 pm_restrict_gfp_mask();
543 error = dpm_suspend_start(PMSG_QUIESCE);
544 if (!error) {
545 error = resume_target_kernel(platform_mode);
546 /*
547 * The above should either succeed and jump to the new kernel,
548 * or return with an error. Otherwise things are just
549 * undefined, so let's be paranoid.
550 */
551 BUG_ON(!error);
552 }
553 dpm_resume_end(PMSG_RECOVER);
554 pm_restore_gfp_mask();
555 resume_console();
556 pm_restore_console();
557 return error;
558}
559
560/**
561 * hibernation_platform_enter - Power off the system using the platform driver.
562 */
563int hibernation_platform_enter(void)
564{
565 int error;
566
567 if (!hibernation_ops)
568 return -ENOSYS;
569
570 /*
571 * We have cancelled the power transition by running
572 * hibernation_ops->finish() before saving the image, so we should let
573 * the firmware know that we're going to enter the sleep state after all
574 */
575 error = hibernation_ops->begin(PMSG_HIBERNATE);
576 if (error)
577 goto Close;
578
579 entering_platform_hibernation = true;
580 suspend_console();
581 error = dpm_suspend_start(PMSG_HIBERNATE);
582 if (error) {
583 if (hibernation_ops->recover)
584 hibernation_ops->recover();
585 goto Resume_devices;
586 }
587
588 error = dpm_suspend_end(PMSG_HIBERNATE);
589 if (error)
590 goto Resume_devices;
591
592 error = hibernation_ops->prepare();
593 if (error)
594 goto Platform_finish;
595
596 error = pm_sleep_disable_secondary_cpus();
597 if (error)
598 goto Enable_cpus;
599
600 local_irq_disable();
601 system_state = SYSTEM_SUSPEND;
602 syscore_suspend();
603 if (pm_wakeup_pending()) {
604 error = -EAGAIN;
605 goto Power_up;
606 }
607
608 hibernation_ops->enter();
609 /* We should never get here */
610 while (1);
611
612 Power_up:
613 syscore_resume();
614 system_state = SYSTEM_RUNNING;
615 local_irq_enable();
616
617 Enable_cpus:
618 pm_sleep_enable_secondary_cpus();
619
620 Platform_finish:
621 hibernation_ops->finish();
622
623 dpm_resume_start(PMSG_RESTORE);
624
625 Resume_devices:
626 entering_platform_hibernation = false;
627 dpm_resume_end(PMSG_RESTORE);
628 resume_console();
629
630 Close:
631 hibernation_ops->end();
632
633 return error;
634}
635
636/**
637 * power_down - Shut the machine down for hibernation.
638 *
639 * Use the platform driver, if configured, to put the system into the sleep
640 * state corresponding to hibernation, or try to power it off or reboot,
641 * depending on the value of hibernation_mode.
642 */
643static void power_down(void)
644{
645 int error;
646
647#ifdef CONFIG_SUSPEND
648 if (hibernation_mode == HIBERNATION_SUSPEND) {
649 error = suspend_devices_and_enter(mem_sleep_current);
650 if (error) {
651 hibernation_mode = hibernation_ops ?
652 HIBERNATION_PLATFORM :
653 HIBERNATION_SHUTDOWN;
654 } else {
655 /* Restore swap signature. */
656 error = swsusp_unmark();
657 if (error)
658 pr_err("Swap will be unusable! Try swapon -a.\n");
659
660 return;
661 }
662 }
663#endif
664
665 switch (hibernation_mode) {
666 case HIBERNATION_REBOOT:
667 kernel_restart(NULL);
668 break;
669 case HIBERNATION_PLATFORM:
670 error = hibernation_platform_enter();
671 if (error == -EAGAIN || error == -EBUSY) {
672 swsusp_unmark();
673 events_check_enabled = false;
674 pr_info("Wakeup event detected during hibernation, rolling back.\n");
675 return;
676 }
677 fallthrough;
678 case HIBERNATION_SHUTDOWN:
679 if (kernel_can_power_off())
680 kernel_power_off();
681 break;
682 }
683 kernel_halt();
684 /*
685 * Valid image is on the disk, if we continue we risk serious data
686 * corruption after resume.
687 */
688 pr_crit("Power down manually\n");
689 while (1)
690 cpu_relax();
691}
692
693static int load_image_and_restore(void)
694{
695 int error;
696 unsigned int flags;
697
698 pm_pr_dbg("Loading hibernation image.\n");
699
700 lock_device_hotplug();
701 error = create_basic_memory_bitmaps();
702 if (error) {
703 swsusp_close();
704 goto Unlock;
705 }
706
707 error = swsusp_read(&flags);
708 swsusp_close();
709 if (!error)
710 error = hibernation_restore(flags & SF_PLATFORM_MODE);
711
712 pr_err("Failed to load image, recovering.\n");
713 swsusp_free();
714 free_basic_memory_bitmaps();
715 Unlock:
716 unlock_device_hotplug();
717
718 return error;
719}
720
721/**
722 * hibernate - Carry out system hibernation, including saving the image.
723 */
724int hibernate(void)
725{
726 bool snapshot_test = false;
727 unsigned int sleep_flags;
728 int error;
729
730 if (!hibernation_available()) {
731 pm_pr_dbg("Hibernation not available.\n");
732 return -EPERM;
733 }
734
735 sleep_flags = lock_system_sleep();
736 /* The snapshot device should not be opened while we're running */
737 if (!hibernate_acquire()) {
738 error = -EBUSY;
739 goto Unlock;
740 }
741
742 pr_info("hibernation entry\n");
743 pm_prepare_console();
744 error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
745 if (error)
746 goto Restore;
747
748 ksys_sync_helper();
749
750 error = freeze_processes();
751 if (error)
752 goto Exit;
753
754 lock_device_hotplug();
755 /* Allocate memory management structures */
756 error = create_basic_memory_bitmaps();
757 if (error)
758 goto Thaw;
759
760 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
761 if (error || freezer_test_done)
762 goto Free_bitmaps;
763
764 if (in_suspend) {
765 unsigned int flags = 0;
766
767 if (hibernation_mode == HIBERNATION_PLATFORM)
768 flags |= SF_PLATFORM_MODE;
769 if (nocompress)
770 flags |= SF_NOCOMPRESS_MODE;
771 else
772 flags |= SF_CRC32_MODE;
773
774 pm_pr_dbg("Writing hibernation image.\n");
775 error = swsusp_write(flags);
776 swsusp_free();
777 if (!error) {
778 if (hibernation_mode == HIBERNATION_TEST_RESUME)
779 snapshot_test = true;
780 else
781 power_down();
782 }
783 in_suspend = 0;
784 pm_restore_gfp_mask();
785 } else {
786 pm_pr_dbg("Hibernation image restored successfully.\n");
787 }
788
789 Free_bitmaps:
790 free_basic_memory_bitmaps();
791 Thaw:
792 unlock_device_hotplug();
793 if (snapshot_test) {
794 pm_pr_dbg("Checking hibernation image\n");
795 error = swsusp_check(false);
796 if (!error)
797 error = load_image_and_restore();
798 }
799 thaw_processes();
800
801 /* Don't bother checking whether freezer_test_done is true */
802 freezer_test_done = false;
803 Exit:
804 pm_notifier_call_chain(PM_POST_HIBERNATION);
805 Restore:
806 pm_restore_console();
807 hibernate_release();
808 Unlock:
809 unlock_system_sleep(sleep_flags);
810 pr_info("hibernation exit\n");
811
812 return error;
813}
814
815/**
816 * hibernate_quiet_exec - Execute a function with all devices frozen.
817 * @func: Function to execute.
818 * @data: Data pointer to pass to @func.
819 *
820 * Return the @func return value or an error code if it cannot be executed.
821 */
822int hibernate_quiet_exec(int (*func)(void *data), void *data)
823{
824 unsigned int sleep_flags;
825 int error;
826
827 sleep_flags = lock_system_sleep();
828
829 if (!hibernate_acquire()) {
830 error = -EBUSY;
831 goto unlock;
832 }
833
834 pm_prepare_console();
835
836 error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
837 if (error)
838 goto restore;
839
840 error = freeze_processes();
841 if (error)
842 goto exit;
843
844 lock_device_hotplug();
845
846 pm_suspend_clear_flags();
847
848 error = platform_begin(true);
849 if (error)
850 goto thaw;
851
852 error = freeze_kernel_threads();
853 if (error)
854 goto thaw;
855
856 error = dpm_prepare(PMSG_FREEZE);
857 if (error)
858 goto dpm_complete;
859
860 suspend_console();
861
862 error = dpm_suspend(PMSG_FREEZE);
863 if (error)
864 goto dpm_resume;
865
866 error = dpm_suspend_end(PMSG_FREEZE);
867 if (error)
868 goto dpm_resume;
869
870 error = platform_pre_snapshot(true);
871 if (error)
872 goto skip;
873
874 error = func(data);
875
876skip:
877 platform_finish(true);
878
879 dpm_resume_start(PMSG_THAW);
880
881dpm_resume:
882 dpm_resume(PMSG_THAW);
883
884 resume_console();
885
886dpm_complete:
887 dpm_complete(PMSG_THAW);
888
889 thaw_kernel_threads();
890
891thaw:
892 platform_end(true);
893
894 unlock_device_hotplug();
895
896 thaw_processes();
897
898exit:
899 pm_notifier_call_chain(PM_POST_HIBERNATION);
900
901restore:
902 pm_restore_console();
903
904 hibernate_release();
905
906unlock:
907 unlock_system_sleep(sleep_flags);
908
909 return error;
910}
911EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
912
913static int __init find_resume_device(void)
914{
915 if (!strlen(resume_file))
916 return -ENOENT;
917
918 pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
919
920 if (resume_delay) {
921 pr_info("Waiting %dsec before reading resume device ...\n",
922 resume_delay);
923 ssleep(resume_delay);
924 }
925
926 /* Check if the device is there */
927 if (!early_lookup_bdev(resume_file, &swsusp_resume_device))
928 return 0;
929
930 /*
931 * Some device discovery might still be in progress; we need to wait for
932 * this to finish.
933 */
934 wait_for_device_probe();
935 if (resume_wait) {
936 while (early_lookup_bdev(resume_file, &swsusp_resume_device))
937 msleep(10);
938 async_synchronize_full();
939 }
940
941 return early_lookup_bdev(resume_file, &swsusp_resume_device);
942}
943
944static int software_resume(void)
945{
946 int error;
947
948 pm_pr_dbg("Hibernation image partition %d:%d present\n",
949 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
950
951 pm_pr_dbg("Looking for hibernation image.\n");
952
953 mutex_lock(&system_transition_mutex);
954 error = swsusp_check(true);
955 if (error)
956 goto Unlock;
957
958 /* The snapshot device should not be opened while we're running */
959 if (!hibernate_acquire()) {
960 error = -EBUSY;
961 swsusp_close();
962 goto Unlock;
963 }
964
965 pr_info("resume from hibernation\n");
966 pm_prepare_console();
967 error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
968 if (error)
969 goto Restore;
970
971 pm_pr_dbg("Preparing processes for hibernation restore.\n");
972 error = freeze_processes();
973 if (error)
974 goto Close_Finish;
975
976 error = freeze_kernel_threads();
977 if (error) {
978 thaw_processes();
979 goto Close_Finish;
980 }
981
982 error = load_image_and_restore();
983 thaw_processes();
984 Finish:
985 pm_notifier_call_chain(PM_POST_RESTORE);
986 Restore:
987 pm_restore_console();
988 pr_info("resume failed (%d)\n", error);
989 hibernate_release();
990 /* For success case, the suspend path will release the lock */
991 Unlock:
992 mutex_unlock(&system_transition_mutex);
993 pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
994 return error;
995 Close_Finish:
996 swsusp_close();
997 goto Finish;
998}
999
1000/**
1001 * software_resume_initcall - Resume from a saved hibernation image.
1002 *
1003 * This routine is called as a late initcall, when all devices have been
1004 * discovered and initialized already.
1005 *
1006 * The image reading code is called to see if there is a hibernation image
1007 * available for reading. If that is the case, devices are quiesced and the
1008 * contents of memory is restored from the saved image.
1009 *
1010 * If this is successful, control reappears in the restored target kernel in
1011 * hibernation_snapshot() which returns to hibernate(). Otherwise, the routine
1012 * attempts to recover gracefully and make the kernel return to the normal mode
1013 * of operation.
1014 */
1015static int __init software_resume_initcall(void)
1016{
1017 /*
1018 * If the user said "noresume".. bail out early.
1019 */
1020 if (noresume || !hibernation_available())
1021 return 0;
1022
1023 if (!swsusp_resume_device) {
1024 int error = find_resume_device();
1025
1026 if (error)
1027 return error;
1028 }
1029
1030 return software_resume();
1031}
1032late_initcall_sync(software_resume_initcall);
1033
1034
1035static const char * const hibernation_modes[] = {
1036 [HIBERNATION_PLATFORM] = "platform",
1037 [HIBERNATION_SHUTDOWN] = "shutdown",
1038 [HIBERNATION_REBOOT] = "reboot",
1039#ifdef CONFIG_SUSPEND
1040 [HIBERNATION_SUSPEND] = "suspend",
1041#endif
1042 [HIBERNATION_TEST_RESUME] = "test_resume",
1043};
1044
1045/*
1046 * /sys/power/disk - Control hibernation mode.
1047 *
1048 * Hibernation can be handled in several ways. There are a few different ways
1049 * to put the system into the sleep state: using the platform driver (e.g. ACPI
1050 * or other hibernation_ops), powering it off or rebooting it (for testing
1051 * mostly).
1052 *
1053 * The sysfs file /sys/power/disk provides an interface for selecting the
1054 * hibernation mode to use. Reading from this file causes the available modes
1055 * to be printed. There are 3 modes that can be supported:
1056 *
1057 * 'platform'
1058 * 'shutdown'
1059 * 'reboot'
1060 *
1061 * If a platform hibernation driver is in use, 'platform' will be supported
1062 * and will be used by default. Otherwise, 'shutdown' will be used by default.
1063 * The selected option (i.e. the one corresponding to the current value of
1064 * hibernation_mode) is enclosed by a square bracket.
1065 *
1066 * To select a given hibernation mode it is necessary to write the mode's
1067 * string representation (as returned by reading from /sys/power/disk) back
1068 * into /sys/power/disk.
1069 */
1070
1071static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1072 char *buf)
1073{
1074 int i;
1075 char *start = buf;
1076
1077 if (!hibernation_available())
1078 return sprintf(buf, "[disabled]\n");
1079
1080 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1081 if (!hibernation_modes[i])
1082 continue;
1083 switch (i) {
1084 case HIBERNATION_SHUTDOWN:
1085 case HIBERNATION_REBOOT:
1086#ifdef CONFIG_SUSPEND
1087 case HIBERNATION_SUSPEND:
1088#endif
1089 case HIBERNATION_TEST_RESUME:
1090 break;
1091 case HIBERNATION_PLATFORM:
1092 if (hibernation_ops)
1093 break;
1094 /* not a valid mode, continue with loop */
1095 continue;
1096 }
1097 if (i == hibernation_mode)
1098 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
1099 else
1100 buf += sprintf(buf, "%s ", hibernation_modes[i]);
1101 }
1102 buf += sprintf(buf, "\n");
1103 return buf-start;
1104}
1105
1106static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1107 const char *buf, size_t n)
1108{
1109 int mode = HIBERNATION_INVALID;
1110 unsigned int sleep_flags;
1111 int error = 0;
1112 int len;
1113 char *p;
1114 int i;
1115
1116 if (!hibernation_available())
1117 return -EPERM;
1118
1119 p = memchr(buf, '\n', n);
1120 len = p ? p - buf : n;
1121
1122 sleep_flags = lock_system_sleep();
1123 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1124 if (len == strlen(hibernation_modes[i])
1125 && !strncmp(buf, hibernation_modes[i], len)) {
1126 mode = i;
1127 break;
1128 }
1129 }
1130 if (mode != HIBERNATION_INVALID) {
1131 switch (mode) {
1132 case HIBERNATION_SHUTDOWN:
1133 case HIBERNATION_REBOOT:
1134#ifdef CONFIG_SUSPEND
1135 case HIBERNATION_SUSPEND:
1136#endif
1137 case HIBERNATION_TEST_RESUME:
1138 hibernation_mode = mode;
1139 break;
1140 case HIBERNATION_PLATFORM:
1141 if (hibernation_ops)
1142 hibernation_mode = mode;
1143 else
1144 error = -EINVAL;
1145 }
1146 } else
1147 error = -EINVAL;
1148
1149 if (!error)
1150 pm_pr_dbg("Hibernation mode set to '%s'\n",
1151 hibernation_modes[mode]);
1152 unlock_system_sleep(sleep_flags);
1153 return error ? error : n;
1154}
1155
1156power_attr(disk);
1157
1158static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1159 char *buf)
1160{
1161 return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1162 MINOR(swsusp_resume_device));
1163}
1164
1165static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1166 const char *buf, size_t n)
1167{
1168 unsigned int sleep_flags;
1169 int len = n;
1170 char *name;
1171 dev_t dev;
1172 int error;
1173
1174 if (!hibernation_available())
1175 return n;
1176
1177 if (len && buf[len-1] == '\n')
1178 len--;
1179 name = kstrndup(buf, len, GFP_KERNEL);
1180 if (!name)
1181 return -ENOMEM;
1182
1183 error = lookup_bdev(name, &dev);
1184 if (error) {
1185 unsigned maj, min, offset;
1186 char *p, dummy;
1187
1188 error = 0;
1189 if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 ||
1190 sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset,
1191 &dummy) == 3) {
1192 dev = MKDEV(maj, min);
1193 if (maj != MAJOR(dev) || min != MINOR(dev))
1194 error = -EINVAL;
1195 } else {
1196 dev = new_decode_dev(simple_strtoul(name, &p, 16));
1197 if (*p)
1198 error = -EINVAL;
1199 }
1200 }
1201 kfree(name);
1202 if (error)
1203 return error;
1204
1205 sleep_flags = lock_system_sleep();
1206 swsusp_resume_device = dev;
1207 unlock_system_sleep(sleep_flags);
1208
1209 pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1210 swsusp_resume_device);
1211 noresume = 0;
1212 software_resume();
1213 return n;
1214}
1215
1216power_attr(resume);
1217
1218static ssize_t resume_offset_show(struct kobject *kobj,
1219 struct kobj_attribute *attr, char *buf)
1220{
1221 return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1222}
1223
1224static ssize_t resume_offset_store(struct kobject *kobj,
1225 struct kobj_attribute *attr, const char *buf,
1226 size_t n)
1227{
1228 unsigned long long offset;
1229 int rc;
1230
1231 rc = kstrtoull(buf, 0, &offset);
1232 if (rc)
1233 return rc;
1234 swsusp_resume_block = offset;
1235
1236 return n;
1237}
1238
1239power_attr(resume_offset);
1240
1241static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1242 char *buf)
1243{
1244 return sprintf(buf, "%lu\n", image_size);
1245}
1246
1247static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1248 const char *buf, size_t n)
1249{
1250 unsigned long size;
1251
1252 if (sscanf(buf, "%lu", &size) == 1) {
1253 image_size = size;
1254 return n;
1255 }
1256
1257 return -EINVAL;
1258}
1259
1260power_attr(image_size);
1261
1262static ssize_t reserved_size_show(struct kobject *kobj,
1263 struct kobj_attribute *attr, char *buf)
1264{
1265 return sprintf(buf, "%lu\n", reserved_size);
1266}
1267
1268static ssize_t reserved_size_store(struct kobject *kobj,
1269 struct kobj_attribute *attr,
1270 const char *buf, size_t n)
1271{
1272 unsigned long size;
1273
1274 if (sscanf(buf, "%lu", &size) == 1) {
1275 reserved_size = size;
1276 return n;
1277 }
1278
1279 return -EINVAL;
1280}
1281
1282power_attr(reserved_size);
1283
1284static struct attribute *g[] = {
1285 &disk_attr.attr,
1286 &resume_offset_attr.attr,
1287 &resume_attr.attr,
1288 &image_size_attr.attr,
1289 &reserved_size_attr.attr,
1290 NULL,
1291};
1292
1293
1294static const struct attribute_group attr_group = {
1295 .attrs = g,
1296};
1297
1298
1299static int __init pm_disk_init(void)
1300{
1301 return sysfs_create_group(power_kobj, &attr_group);
1302}
1303
1304core_initcall(pm_disk_init);
1305
1306
1307static int __init resume_setup(char *str)
1308{
1309 if (noresume)
1310 return 1;
1311
1312 strncpy(resume_file, str, 255);
1313 return 1;
1314}
1315
1316static int __init resume_offset_setup(char *str)
1317{
1318 unsigned long long offset;
1319
1320 if (noresume)
1321 return 1;
1322
1323 if (sscanf(str, "%llu", &offset) == 1)
1324 swsusp_resume_block = offset;
1325
1326 return 1;
1327}
1328
1329static int __init hibernate_setup(char *str)
1330{
1331 if (!strncmp(str, "noresume", 8)) {
1332 noresume = 1;
1333 } else if (!strncmp(str, "nocompress", 10)) {
1334 nocompress = 1;
1335 } else if (!strncmp(str, "no", 2)) {
1336 noresume = 1;
1337 nohibernate = 1;
1338 } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1339 && !strncmp(str, "protect_image", 13)) {
1340 enable_restore_image_protection();
1341 }
1342 return 1;
1343}
1344
1345static int __init noresume_setup(char *str)
1346{
1347 noresume = 1;
1348 return 1;
1349}
1350
1351static int __init resumewait_setup(char *str)
1352{
1353 resume_wait = 1;
1354 return 1;
1355}
1356
1357static int __init resumedelay_setup(char *str)
1358{
1359 int rc = kstrtouint(str, 0, &resume_delay);
1360
1361 if (rc)
1362 pr_warn("resumedelay: bad option string '%s'\n", str);
1363 return 1;
1364}
1365
1366static int __init nohibernate_setup(char *str)
1367{
1368 noresume = 1;
1369 nohibernate = 1;
1370 return 1;
1371}
1372
1373__setup("noresume", noresume_setup);
1374__setup("resume_offset=", resume_offset_setup);
1375__setup("resume=", resume_setup);
1376__setup("hibernate=", hibernate_setup);
1377__setup("resumewait", resumewait_setup);
1378__setup("resumedelay=", resumedelay_setup);
1379__setup("nohibernate", nohibernate_setup);