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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 * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
9 *
10 * This file is released under the GPLv2.
11 */
12
13#define pr_fmt(fmt) "PM: " fmt
14
15#include <linux/export.h>
16#include <linux/suspend.h>
17#include <linux/syscalls.h>
18#include <linux/reboot.h>
19#include <linux/string.h>
20#include <linux/device.h>
21#include <linux/async.h>
22#include <linux/delay.h>
23#include <linux/fs.h>
24#include <linux/mount.h>
25#include <linux/pm.h>
26#include <linux/nmi.h>
27#include <linux/console.h>
28#include <linux/cpu.h>
29#include <linux/freezer.h>
30#include <linux/gfp.h>
31#include <linux/syscore_ops.h>
32#include <linux/ctype.h>
33#include <linux/genhd.h>
34#include <linux/ktime.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
71bool hibernation_available(void)
72{
73 return (nohibernate == 0);
74}
75
76/**
77 * hibernation_set_ops - Set the global hibernate operations.
78 * @ops: Hibernation operations to use in subsequent hibernation transitions.
79 */
80void hibernation_set_ops(const struct platform_hibernation_ops *ops)
81{
82 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
83 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
84 && ops->restore_cleanup && ops->leave)) {
85 WARN_ON(1);
86 return;
87 }
88 lock_system_sleep();
89 hibernation_ops = ops;
90 if (ops)
91 hibernation_mode = HIBERNATION_PLATFORM;
92 else if (hibernation_mode == HIBERNATION_PLATFORM)
93 hibernation_mode = HIBERNATION_SHUTDOWN;
94
95 unlock_system_sleep();
96}
97EXPORT_SYMBOL_GPL(hibernation_set_ops);
98
99static bool entering_platform_hibernation;
100
101bool system_entering_hibernation(void)
102{
103 return entering_platform_hibernation;
104}
105EXPORT_SYMBOL(system_entering_hibernation);
106
107#ifdef CONFIG_PM_DEBUG
108static void hibernation_debug_sleep(void)
109{
110 pr_info("hibernation debug: Waiting for 5 seconds.\n");
111 mdelay(5000);
112}
113
114static int hibernation_test(int level)
115{
116 if (pm_test_level == level) {
117 hibernation_debug_sleep();
118 return 1;
119 }
120 return 0;
121}
122#else /* !CONFIG_PM_DEBUG */
123static int hibernation_test(int level) { return 0; }
124#endif /* !CONFIG_PM_DEBUG */
125
126/**
127 * platform_begin - Call platform to start hibernation.
128 * @platform_mode: Whether or not to use the platform driver.
129 */
130static int platform_begin(int platform_mode)
131{
132 return (platform_mode && hibernation_ops) ?
133 hibernation_ops->begin() : 0;
134}
135
136/**
137 * platform_end - Call platform to finish transition to the working state.
138 * @platform_mode: Whether or not to use the platform driver.
139 */
140static void platform_end(int platform_mode)
141{
142 if (platform_mode && hibernation_ops)
143 hibernation_ops->end();
144}
145
146/**
147 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
148 * @platform_mode: Whether or not to use the platform driver.
149 *
150 * Use the platform driver to prepare the system for creating a hibernate image,
151 * if so configured, and return an error code if that fails.
152 */
153
154static int platform_pre_snapshot(int platform_mode)
155{
156 return (platform_mode && hibernation_ops) ?
157 hibernation_ops->pre_snapshot() : 0;
158}
159
160/**
161 * platform_leave - Call platform to prepare a transition to the working state.
162 * @platform_mode: Whether or not to use the platform driver.
163 *
164 * Use the platform driver prepare to prepare the machine for switching to the
165 * normal mode of operation.
166 *
167 * This routine is called on one CPU with interrupts disabled.
168 */
169static void platform_leave(int platform_mode)
170{
171 if (platform_mode && hibernation_ops)
172 hibernation_ops->leave();
173}
174
175/**
176 * platform_finish - Call platform to switch the system to the working state.
177 * @platform_mode: Whether or not to use the platform driver.
178 *
179 * Use the platform driver to switch the machine to the normal mode of
180 * operation.
181 *
182 * This routine must be called after platform_prepare().
183 */
184static void platform_finish(int platform_mode)
185{
186 if (platform_mode && hibernation_ops)
187 hibernation_ops->finish();
188}
189
190/**
191 * platform_pre_restore - Prepare for hibernate image restoration.
192 * @platform_mode: Whether or not to use the platform driver.
193 *
194 * Use the platform driver to prepare the system for resume from a hibernation
195 * image.
196 *
197 * If the restore fails after this function has been called,
198 * platform_restore_cleanup() must be called.
199 */
200static int platform_pre_restore(int platform_mode)
201{
202 return (platform_mode && hibernation_ops) ?
203 hibernation_ops->pre_restore() : 0;
204}
205
206/**
207 * platform_restore_cleanup - Switch to the working state after failing restore.
208 * @platform_mode: Whether or not to use the platform driver.
209 *
210 * Use the platform driver to switch the system to the normal mode of operation
211 * after a failing restore.
212 *
213 * If platform_pre_restore() has been called before the failing restore, this
214 * function must be called too, regardless of the result of
215 * platform_pre_restore().
216 */
217static void platform_restore_cleanup(int platform_mode)
218{
219 if (platform_mode && hibernation_ops)
220 hibernation_ops->restore_cleanup();
221}
222
223/**
224 * platform_recover - Recover from a failure to suspend devices.
225 * @platform_mode: Whether or not to use the platform driver.
226 */
227static void platform_recover(int platform_mode)
228{
229 if (platform_mode && hibernation_ops && hibernation_ops->recover)
230 hibernation_ops->recover();
231}
232
233/**
234 * swsusp_show_speed - Print time elapsed between two events during hibernation.
235 * @start: Starting event.
236 * @stop: Final event.
237 * @nr_pages: Number of memory pages processed between @start and @stop.
238 * @msg: Additional diagnostic message to print.
239 */
240void swsusp_show_speed(ktime_t start, ktime_t stop,
241 unsigned nr_pages, char *msg)
242{
243 ktime_t diff;
244 u64 elapsed_centisecs64;
245 unsigned int centisecs;
246 unsigned int k;
247 unsigned int kps;
248
249 diff = ktime_sub(stop, start);
250 elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
251 centisecs = elapsed_centisecs64;
252 if (centisecs == 0)
253 centisecs = 1; /* avoid div-by-zero */
254 k = nr_pages * (PAGE_SIZE / 1024);
255 kps = (k * 100) / centisecs;
256 pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
257 msg, k, centisecs / 100, centisecs % 100, kps / 1000,
258 (kps % 1000) / 10);
259}
260
261/**
262 * create_image - Create a hibernation image.
263 * @platform_mode: Whether or not to use the platform driver.
264 *
265 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
266 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
267 *
268 * Control reappears in this routine after the subsequent restore.
269 */
270static int create_image(int platform_mode)
271{
272 int error;
273
274 error = dpm_suspend_end(PMSG_FREEZE);
275 if (error) {
276 pr_err("Some devices failed to power down, aborting hibernation\n");
277 return error;
278 }
279
280 error = platform_pre_snapshot(platform_mode);
281 if (error || hibernation_test(TEST_PLATFORM))
282 goto Platform_finish;
283
284 error = disable_nonboot_cpus();
285 if (error || hibernation_test(TEST_CPUS))
286 goto Enable_cpus;
287
288 local_irq_disable();
289
290 error = syscore_suspend();
291 if (error) {
292 pr_err("Some system devices failed to power down, aborting hibernation\n");
293 goto Enable_irqs;
294 }
295
296 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
297 goto Power_up;
298
299 in_suspend = 1;
300 save_processor_state();
301 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
302 error = swsusp_arch_suspend();
303 /* Restore control flow magically appears here */
304 restore_processor_state();
305 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
306 if (error)
307 pr_err("Error %d creating hibernation image\n", error);
308
309 if (!in_suspend) {
310 events_check_enabled = false;
311 clear_free_pages();
312 }
313
314 platform_leave(platform_mode);
315
316 Power_up:
317 syscore_resume();
318
319 Enable_irqs:
320 local_irq_enable();
321
322 Enable_cpus:
323 enable_nonboot_cpus();
324
325 Platform_finish:
326 platform_finish(platform_mode);
327
328 dpm_resume_start(in_suspend ?
329 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
330
331 return error;
332}
333
334/**
335 * hibernation_snapshot - Quiesce devices and create a hibernation image.
336 * @platform_mode: If set, use platform driver to prepare for the transition.
337 *
338 * This routine must be called with pm_mutex held.
339 */
340int hibernation_snapshot(int platform_mode)
341{
342 pm_message_t msg;
343 int error;
344
345 pm_suspend_clear_flags();
346 error = platform_begin(platform_mode);
347 if (error)
348 goto Close;
349
350 /* Preallocate image memory before shutting down devices. */
351 error = hibernate_preallocate_memory();
352 if (error)
353 goto Close;
354
355 error = freeze_kernel_threads();
356 if (error)
357 goto Cleanup;
358
359 if (hibernation_test(TEST_FREEZER)) {
360
361 /*
362 * Indicate to the caller that we are returning due to a
363 * successful freezer test.
364 */
365 freezer_test_done = true;
366 goto Thaw;
367 }
368
369 error = dpm_prepare(PMSG_FREEZE);
370 if (error) {
371 dpm_complete(PMSG_RECOVER);
372 goto Thaw;
373 }
374
375 suspend_console();
376 pm_restrict_gfp_mask();
377
378 error = dpm_suspend(PMSG_FREEZE);
379
380 if (error || hibernation_test(TEST_DEVICES))
381 platform_recover(platform_mode);
382 else
383 error = create_image(platform_mode);
384
385 /*
386 * In the case that we call create_image() above, the control
387 * returns here (1) after the image has been created or the
388 * image creation has failed and (2) after a successful restore.
389 */
390
391 /* We may need to release the preallocated image pages here. */
392 if (error || !in_suspend)
393 swsusp_free();
394
395 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
396 dpm_resume(msg);
397
398 if (error || !in_suspend)
399 pm_restore_gfp_mask();
400
401 resume_console();
402 dpm_complete(msg);
403
404 Close:
405 platform_end(platform_mode);
406 return error;
407
408 Thaw:
409 thaw_kernel_threads();
410 Cleanup:
411 swsusp_free();
412 goto Close;
413}
414
415int __weak hibernate_resume_nonboot_cpu_disable(void)
416{
417 return disable_nonboot_cpus();
418}
419
420/**
421 * resume_target_kernel - Restore system state from a hibernation image.
422 * @platform_mode: Whether or not to use the platform driver.
423 *
424 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
425 * contents of highmem that have not been restored yet from the image and run
426 * the low-level code that will restore the remaining contents of memory and
427 * switch to the just restored target kernel.
428 */
429static int resume_target_kernel(bool platform_mode)
430{
431 int error;
432
433 error = dpm_suspend_end(PMSG_QUIESCE);
434 if (error) {
435 pr_err("Some devices failed to power down, aborting resume\n");
436 return error;
437 }
438
439 error = platform_pre_restore(platform_mode);
440 if (error)
441 goto Cleanup;
442
443 error = hibernate_resume_nonboot_cpu_disable();
444 if (error)
445 goto Enable_cpus;
446
447 local_irq_disable();
448
449 error = syscore_suspend();
450 if (error)
451 goto Enable_irqs;
452
453 save_processor_state();
454 error = restore_highmem();
455 if (!error) {
456 error = swsusp_arch_resume();
457 /*
458 * The code below is only ever reached in case of a failure.
459 * Otherwise, execution continues at the place where
460 * swsusp_arch_suspend() was called.
461 */
462 BUG_ON(!error);
463 /*
464 * This call to restore_highmem() reverts the changes made by
465 * the previous one.
466 */
467 restore_highmem();
468 }
469 /*
470 * The only reason why swsusp_arch_resume() can fail is memory being
471 * very tight, so we have to free it as soon as we can to avoid
472 * subsequent failures.
473 */
474 swsusp_free();
475 restore_processor_state();
476 touch_softlockup_watchdog();
477
478 syscore_resume();
479
480 Enable_irqs:
481 local_irq_enable();
482
483 Enable_cpus:
484 enable_nonboot_cpus();
485
486 Cleanup:
487 platform_restore_cleanup(platform_mode);
488
489 dpm_resume_start(PMSG_RECOVER);
490
491 return error;
492}
493
494/**
495 * hibernation_restore - Quiesce devices and restore from a hibernation image.
496 * @platform_mode: If set, use platform driver to prepare for the transition.
497 *
498 * This routine must be called with pm_mutex held. If it is successful, control
499 * reappears in the restored target kernel in hibernation_snapshot().
500 */
501int hibernation_restore(int platform_mode)
502{
503 int error;
504
505 pm_prepare_console();
506 suspend_console();
507 pm_restrict_gfp_mask();
508 error = dpm_suspend_start(PMSG_QUIESCE);
509 if (!error) {
510 error = resume_target_kernel(platform_mode);
511 /*
512 * The above should either succeed and jump to the new kernel,
513 * or return with an error. Otherwise things are just
514 * undefined, so let's be paranoid.
515 */
516 BUG_ON(!error);
517 }
518 dpm_resume_end(PMSG_RECOVER);
519 pm_restore_gfp_mask();
520 resume_console();
521 pm_restore_console();
522 return error;
523}
524
525/**
526 * hibernation_platform_enter - Power off the system using the platform driver.
527 */
528int hibernation_platform_enter(void)
529{
530 int error;
531
532 if (!hibernation_ops)
533 return -ENOSYS;
534
535 /*
536 * We have cancelled the power transition by running
537 * hibernation_ops->finish() before saving the image, so we should let
538 * the firmware know that we're going to enter the sleep state after all
539 */
540 error = hibernation_ops->begin();
541 if (error)
542 goto Close;
543
544 entering_platform_hibernation = true;
545 suspend_console();
546 error = dpm_suspend_start(PMSG_HIBERNATE);
547 if (error) {
548 if (hibernation_ops->recover)
549 hibernation_ops->recover();
550 goto Resume_devices;
551 }
552
553 error = dpm_suspend_end(PMSG_HIBERNATE);
554 if (error)
555 goto Resume_devices;
556
557 error = hibernation_ops->prepare();
558 if (error)
559 goto Platform_finish;
560
561 error = disable_nonboot_cpus();
562 if (error)
563 goto Enable_cpus;
564
565 local_irq_disable();
566 syscore_suspend();
567 if (pm_wakeup_pending()) {
568 error = -EAGAIN;
569 goto Power_up;
570 }
571
572 hibernation_ops->enter();
573 /* We should never get here */
574 while (1);
575
576 Power_up:
577 syscore_resume();
578 local_irq_enable();
579
580 Enable_cpus:
581 enable_nonboot_cpus();
582
583 Platform_finish:
584 hibernation_ops->finish();
585
586 dpm_resume_start(PMSG_RESTORE);
587
588 Resume_devices:
589 entering_platform_hibernation = false;
590 dpm_resume_end(PMSG_RESTORE);
591 resume_console();
592
593 Close:
594 hibernation_ops->end();
595
596 return error;
597}
598
599/**
600 * power_down - Shut the machine down for hibernation.
601 *
602 * Use the platform driver, if configured, to put the system into the sleep
603 * state corresponding to hibernation, or try to power it off or reboot,
604 * depending on the value of hibernation_mode.
605 */
606static void power_down(void)
607{
608#ifdef CONFIG_SUSPEND
609 int error;
610
611 if (hibernation_mode == HIBERNATION_SUSPEND) {
612 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
613 if (error) {
614 hibernation_mode = hibernation_ops ?
615 HIBERNATION_PLATFORM :
616 HIBERNATION_SHUTDOWN;
617 } else {
618 /* Restore swap signature. */
619 error = swsusp_unmark();
620 if (error)
621 pr_err("Swap will be unusable! Try swapon -a.\n");
622
623 return;
624 }
625 }
626#endif
627
628 switch (hibernation_mode) {
629 case HIBERNATION_REBOOT:
630 kernel_restart(NULL);
631 break;
632 case HIBERNATION_PLATFORM:
633 hibernation_platform_enter();
634 case HIBERNATION_SHUTDOWN:
635 if (pm_power_off)
636 kernel_power_off();
637 break;
638 }
639 kernel_halt();
640 /*
641 * Valid image is on the disk, if we continue we risk serious data
642 * corruption after resume.
643 */
644 pr_crit("Power down manually\n");
645 while (1)
646 cpu_relax();
647}
648
649static int load_image_and_restore(void)
650{
651 int error;
652 unsigned int flags;
653
654 pm_pr_dbg("Loading hibernation image.\n");
655
656 lock_device_hotplug();
657 error = create_basic_memory_bitmaps();
658 if (error)
659 goto Unlock;
660
661 error = swsusp_read(&flags);
662 swsusp_close(FMODE_READ);
663 if (!error)
664 hibernation_restore(flags & SF_PLATFORM_MODE);
665
666 pr_err("Failed to load hibernation image, recovering.\n");
667 swsusp_free();
668 free_basic_memory_bitmaps();
669 Unlock:
670 unlock_device_hotplug();
671
672 return error;
673}
674
675/**
676 * hibernate - Carry out system hibernation, including saving the image.
677 */
678int hibernate(void)
679{
680 int error, nr_calls = 0;
681 bool snapshot_test = false;
682
683 if (!hibernation_available()) {
684 pm_pr_dbg("Hibernation not available.\n");
685 return -EPERM;
686 }
687
688 lock_system_sleep();
689 /* The snapshot device should not be opened while we're running */
690 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
691 error = -EBUSY;
692 goto Unlock;
693 }
694
695 pr_info("hibernation entry\n");
696 pm_prepare_console();
697 error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
698 if (error) {
699 nr_calls--;
700 goto Exit;
701 }
702
703 pr_info("Syncing filesystems ... \n");
704 ksys_sync();
705 pr_info("done.\n");
706
707 error = freeze_processes();
708 if (error)
709 goto Exit;
710
711 lock_device_hotplug();
712 /* Allocate memory management structures */
713 error = create_basic_memory_bitmaps();
714 if (error)
715 goto Thaw;
716
717 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
718 if (error || freezer_test_done)
719 goto Free_bitmaps;
720
721 if (in_suspend) {
722 unsigned int flags = 0;
723
724 if (hibernation_mode == HIBERNATION_PLATFORM)
725 flags |= SF_PLATFORM_MODE;
726 if (nocompress)
727 flags |= SF_NOCOMPRESS_MODE;
728 else
729 flags |= SF_CRC32_MODE;
730
731 pm_pr_dbg("Writing image.\n");
732 error = swsusp_write(flags);
733 swsusp_free();
734 if (!error) {
735 if (hibernation_mode == HIBERNATION_TEST_RESUME)
736 snapshot_test = true;
737 else
738 power_down();
739 }
740 in_suspend = 0;
741 pm_restore_gfp_mask();
742 } else {
743 pm_pr_dbg("Image restored successfully.\n");
744 }
745
746 Free_bitmaps:
747 free_basic_memory_bitmaps();
748 Thaw:
749 unlock_device_hotplug();
750 if (snapshot_test) {
751 pm_pr_dbg("Checking hibernation image\n");
752 error = swsusp_check();
753 if (!error)
754 error = load_image_and_restore();
755 }
756 thaw_processes();
757
758 /* Don't bother checking whether freezer_test_done is true */
759 freezer_test_done = false;
760 Exit:
761 __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
762 pm_restore_console();
763 atomic_inc(&snapshot_device_available);
764 Unlock:
765 unlock_system_sleep();
766 pr_info("hibernation exit\n");
767
768 return error;
769}
770
771
772/**
773 * software_resume - Resume from a saved hibernation image.
774 *
775 * This routine is called as a late initcall, when all devices have been
776 * discovered and initialized already.
777 *
778 * The image reading code is called to see if there is a hibernation image
779 * available for reading. If that is the case, devices are quiesced and the
780 * contents of memory is restored from the saved image.
781 *
782 * If this is successful, control reappears in the restored target kernel in
783 * hibernation_snapshot() which returns to hibernate(). Otherwise, the routine
784 * attempts to recover gracefully and make the kernel return to the normal mode
785 * of operation.
786 */
787static int software_resume(void)
788{
789 int error, nr_calls = 0;
790
791 /*
792 * If the user said "noresume".. bail out early.
793 */
794 if (noresume || !hibernation_available())
795 return 0;
796
797 /*
798 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
799 * is configured into the kernel. Since the regular hibernate
800 * trigger path is via sysfs which takes a buffer mutex before
801 * calling hibernate functions (which take pm_mutex) this can
802 * cause lockdep to complain about a possible ABBA deadlock
803 * which cannot happen since we're in the boot code here and
804 * sysfs can't be invoked yet. Therefore, we use a subclass
805 * here to avoid lockdep complaining.
806 */
807 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
808
809 if (swsusp_resume_device)
810 goto Check_image;
811
812 if (!strlen(resume_file)) {
813 error = -ENOENT;
814 goto Unlock;
815 }
816
817 pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
818
819 if (resume_delay) {
820 pr_info("Waiting %dsec before reading resume device ...\n",
821 resume_delay);
822 ssleep(resume_delay);
823 }
824
825 /* Check if the device is there */
826 swsusp_resume_device = name_to_dev_t(resume_file);
827
828 /*
829 * name_to_dev_t is ineffective to verify parition if resume_file is in
830 * integer format. (e.g. major:minor)
831 */
832 if (isdigit(resume_file[0]) && resume_wait) {
833 int partno;
834 while (!get_gendisk(swsusp_resume_device, &partno))
835 msleep(10);
836 }
837
838 if (!swsusp_resume_device) {
839 /*
840 * Some device discovery might still be in progress; we need
841 * to wait for this to finish.
842 */
843 wait_for_device_probe();
844
845 if (resume_wait) {
846 while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
847 msleep(10);
848 async_synchronize_full();
849 }
850
851 swsusp_resume_device = name_to_dev_t(resume_file);
852 if (!swsusp_resume_device) {
853 error = -ENODEV;
854 goto Unlock;
855 }
856 }
857
858 Check_image:
859 pm_pr_dbg("Hibernation image partition %d:%d present\n",
860 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
861
862 pm_pr_dbg("Looking for hibernation image.\n");
863 error = swsusp_check();
864 if (error)
865 goto Unlock;
866
867 /* The snapshot device should not be opened while we're running */
868 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
869 error = -EBUSY;
870 swsusp_close(FMODE_READ);
871 goto Unlock;
872 }
873
874 pr_info("resume from hibernation\n");
875 pm_prepare_console();
876 error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
877 if (error) {
878 nr_calls--;
879 goto Close_Finish;
880 }
881
882 pm_pr_dbg("Preparing processes for restore.\n");
883 error = freeze_processes();
884 if (error)
885 goto Close_Finish;
886 error = load_image_and_restore();
887 thaw_processes();
888 Finish:
889 __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
890 pm_restore_console();
891 pr_info("resume from hibernation failed (%d)\n", error);
892 atomic_inc(&snapshot_device_available);
893 /* For success case, the suspend path will release the lock */
894 Unlock:
895 mutex_unlock(&pm_mutex);
896 pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
897 return error;
898 Close_Finish:
899 swsusp_close(FMODE_READ);
900 goto Finish;
901}
902
903late_initcall_sync(software_resume);
904
905
906static const char * const hibernation_modes[] = {
907 [HIBERNATION_PLATFORM] = "platform",
908 [HIBERNATION_SHUTDOWN] = "shutdown",
909 [HIBERNATION_REBOOT] = "reboot",
910#ifdef CONFIG_SUSPEND
911 [HIBERNATION_SUSPEND] = "suspend",
912#endif
913 [HIBERNATION_TEST_RESUME] = "test_resume",
914};
915
916/*
917 * /sys/power/disk - Control hibernation mode.
918 *
919 * Hibernation can be handled in several ways. There are a few different ways
920 * to put the system into the sleep state: using the platform driver (e.g. ACPI
921 * or other hibernation_ops), powering it off or rebooting it (for testing
922 * mostly).
923 *
924 * The sysfs file /sys/power/disk provides an interface for selecting the
925 * hibernation mode to use. Reading from this file causes the available modes
926 * to be printed. There are 3 modes that can be supported:
927 *
928 * 'platform'
929 * 'shutdown'
930 * 'reboot'
931 *
932 * If a platform hibernation driver is in use, 'platform' will be supported
933 * and will be used by default. Otherwise, 'shutdown' will be used by default.
934 * The selected option (i.e. the one corresponding to the current value of
935 * hibernation_mode) is enclosed by a square bracket.
936 *
937 * To select a given hibernation mode it is necessary to write the mode's
938 * string representation (as returned by reading from /sys/power/disk) back
939 * into /sys/power/disk.
940 */
941
942static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
943 char *buf)
944{
945 int i;
946 char *start = buf;
947
948 if (!hibernation_available())
949 return sprintf(buf, "[disabled]\n");
950
951 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
952 if (!hibernation_modes[i])
953 continue;
954 switch (i) {
955 case HIBERNATION_SHUTDOWN:
956 case HIBERNATION_REBOOT:
957#ifdef CONFIG_SUSPEND
958 case HIBERNATION_SUSPEND:
959#endif
960 case HIBERNATION_TEST_RESUME:
961 break;
962 case HIBERNATION_PLATFORM:
963 if (hibernation_ops)
964 break;
965 /* not a valid mode, continue with loop */
966 continue;
967 }
968 if (i == hibernation_mode)
969 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
970 else
971 buf += sprintf(buf, "%s ", hibernation_modes[i]);
972 }
973 buf += sprintf(buf, "\n");
974 return buf-start;
975}
976
977static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
978 const char *buf, size_t n)
979{
980 int error = 0;
981 int i;
982 int len;
983 char *p;
984 int mode = HIBERNATION_INVALID;
985
986 if (!hibernation_available())
987 return -EPERM;
988
989 p = memchr(buf, '\n', n);
990 len = p ? p - buf : n;
991
992 lock_system_sleep();
993 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
994 if (len == strlen(hibernation_modes[i])
995 && !strncmp(buf, hibernation_modes[i], len)) {
996 mode = i;
997 break;
998 }
999 }
1000 if (mode != HIBERNATION_INVALID) {
1001 switch (mode) {
1002 case HIBERNATION_SHUTDOWN:
1003 case HIBERNATION_REBOOT:
1004#ifdef CONFIG_SUSPEND
1005 case HIBERNATION_SUSPEND:
1006#endif
1007 case HIBERNATION_TEST_RESUME:
1008 hibernation_mode = mode;
1009 break;
1010 case HIBERNATION_PLATFORM:
1011 if (hibernation_ops)
1012 hibernation_mode = mode;
1013 else
1014 error = -EINVAL;
1015 }
1016 } else
1017 error = -EINVAL;
1018
1019 if (!error)
1020 pm_pr_dbg("Hibernation mode set to '%s'\n",
1021 hibernation_modes[mode]);
1022 unlock_system_sleep();
1023 return error ? error : n;
1024}
1025
1026power_attr(disk);
1027
1028static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1029 char *buf)
1030{
1031 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
1032 MINOR(swsusp_resume_device));
1033}
1034
1035static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1036 const char *buf, size_t n)
1037{
1038 dev_t res;
1039 int len = n;
1040 char *name;
1041
1042 if (len && buf[len-1] == '\n')
1043 len--;
1044 name = kstrndup(buf, len, GFP_KERNEL);
1045 if (!name)
1046 return -ENOMEM;
1047
1048 res = name_to_dev_t(name);
1049 kfree(name);
1050 if (!res)
1051 return -EINVAL;
1052
1053 lock_system_sleep();
1054 swsusp_resume_device = res;
1055 unlock_system_sleep();
1056 pm_pr_dbg("Configured resume from disk to %u\n", swsusp_resume_device);
1057 noresume = 0;
1058 software_resume();
1059 return n;
1060}
1061
1062power_attr(resume);
1063
1064static ssize_t resume_offset_show(struct kobject *kobj,
1065 struct kobj_attribute *attr, char *buf)
1066{
1067 return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1068}
1069
1070static ssize_t resume_offset_store(struct kobject *kobj,
1071 struct kobj_attribute *attr, const char *buf,
1072 size_t n)
1073{
1074 unsigned long long offset;
1075 int rc;
1076
1077 rc = kstrtoull(buf, 0, &offset);
1078 if (rc)
1079 return rc;
1080 swsusp_resume_block = offset;
1081
1082 return n;
1083}
1084
1085power_attr(resume_offset);
1086
1087static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1088 char *buf)
1089{
1090 return sprintf(buf, "%lu\n", image_size);
1091}
1092
1093static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1094 const char *buf, size_t n)
1095{
1096 unsigned long size;
1097
1098 if (sscanf(buf, "%lu", &size) == 1) {
1099 image_size = size;
1100 return n;
1101 }
1102
1103 return -EINVAL;
1104}
1105
1106power_attr(image_size);
1107
1108static ssize_t reserved_size_show(struct kobject *kobj,
1109 struct kobj_attribute *attr, char *buf)
1110{
1111 return sprintf(buf, "%lu\n", reserved_size);
1112}
1113
1114static ssize_t reserved_size_store(struct kobject *kobj,
1115 struct kobj_attribute *attr,
1116 const char *buf, size_t n)
1117{
1118 unsigned long size;
1119
1120 if (sscanf(buf, "%lu", &size) == 1) {
1121 reserved_size = size;
1122 return n;
1123 }
1124
1125 return -EINVAL;
1126}
1127
1128power_attr(reserved_size);
1129
1130static struct attribute * g[] = {
1131 &disk_attr.attr,
1132 &resume_offset_attr.attr,
1133 &resume_attr.attr,
1134 &image_size_attr.attr,
1135 &reserved_size_attr.attr,
1136 NULL,
1137};
1138
1139
1140static const struct attribute_group attr_group = {
1141 .attrs = g,
1142};
1143
1144
1145static int __init pm_disk_init(void)
1146{
1147 return sysfs_create_group(power_kobj, &attr_group);
1148}
1149
1150core_initcall(pm_disk_init);
1151
1152
1153static int __init resume_setup(char *str)
1154{
1155 if (noresume)
1156 return 1;
1157
1158 strncpy( resume_file, str, 255 );
1159 return 1;
1160}
1161
1162static int __init resume_offset_setup(char *str)
1163{
1164 unsigned long long offset;
1165
1166 if (noresume)
1167 return 1;
1168
1169 if (sscanf(str, "%llu", &offset) == 1)
1170 swsusp_resume_block = offset;
1171
1172 return 1;
1173}
1174
1175static int __init hibernate_setup(char *str)
1176{
1177 if (!strncmp(str, "noresume", 8)) {
1178 noresume = 1;
1179 } else if (!strncmp(str, "nocompress", 10)) {
1180 nocompress = 1;
1181 } else if (!strncmp(str, "no", 2)) {
1182 noresume = 1;
1183 nohibernate = 1;
1184 } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1185 && !strncmp(str, "protect_image", 13)) {
1186 enable_restore_image_protection();
1187 }
1188 return 1;
1189}
1190
1191static int __init noresume_setup(char *str)
1192{
1193 noresume = 1;
1194 return 1;
1195}
1196
1197static int __init resumewait_setup(char *str)
1198{
1199 resume_wait = 1;
1200 return 1;
1201}
1202
1203static int __init resumedelay_setup(char *str)
1204{
1205 int rc = kstrtouint(str, 0, &resume_delay);
1206
1207 if (rc)
1208 return rc;
1209 return 1;
1210}
1211
1212static int __init nohibernate_setup(char *str)
1213{
1214 noresume = 1;
1215 nohibernate = 1;
1216 return 1;
1217}
1218
1219__setup("noresume", noresume_setup);
1220__setup("resume_offset=", resume_offset_setup);
1221__setup("resume=", resume_setup);
1222__setup("hibernate=", hibernate_setup);
1223__setup("resumewait", resumewait_setup);
1224__setup("resumedelay=", resumedelay_setup);
1225__setup("nohibernate", nohibernate_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: " 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 <trace/events/power.h>
35
36#include "power.h"
37
38
39static int nocompress;
40static int noresume;
41static int nohibernate;
42static int resume_wait;
43static unsigned int resume_delay;
44static char resume_file[256] = CONFIG_PM_STD_PARTITION;
45dev_t swsusp_resume_device;
46sector_t swsusp_resume_block;
47__visible int in_suspend __nosavedata;
48
49enum {
50 HIBERNATION_INVALID,
51 HIBERNATION_PLATFORM,
52 HIBERNATION_SHUTDOWN,
53 HIBERNATION_REBOOT,
54#ifdef CONFIG_SUSPEND
55 HIBERNATION_SUSPEND,
56#endif
57 HIBERNATION_TEST_RESUME,
58 /* keep last */
59 __HIBERNATION_AFTER_LAST
60};
61#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
62#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
63
64static int hibernation_mode = HIBERNATION_SHUTDOWN;
65
66bool freezer_test_done;
67
68static const struct platform_hibernation_ops *hibernation_ops;
69
70bool hibernation_available(void)
71{
72 return nohibernate == 0 && !security_locked_down(LOCKDOWN_HIBERNATION);
73}
74
75/**
76 * hibernation_set_ops - Set the global hibernate operations.
77 * @ops: Hibernation operations to use in subsequent hibernation transitions.
78 */
79void hibernation_set_ops(const struct platform_hibernation_ops *ops)
80{
81 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
82 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
83 && ops->restore_cleanup && ops->leave)) {
84 WARN_ON(1);
85 return;
86 }
87 lock_system_sleep();
88 hibernation_ops = ops;
89 if (ops)
90 hibernation_mode = HIBERNATION_PLATFORM;
91 else if (hibernation_mode == HIBERNATION_PLATFORM)
92 hibernation_mode = HIBERNATION_SHUTDOWN;
93
94 unlock_system_sleep();
95}
96EXPORT_SYMBOL_GPL(hibernation_set_ops);
97
98static bool entering_platform_hibernation;
99
100bool system_entering_hibernation(void)
101{
102 return entering_platform_hibernation;
103}
104EXPORT_SYMBOL(system_entering_hibernation);
105
106#ifdef CONFIG_PM_DEBUG
107static void hibernation_debug_sleep(void)
108{
109 pr_info("hibernation debug: Waiting for 5 seconds.\n");
110 mdelay(5000);
111}
112
113static int hibernation_test(int level)
114{
115 if (pm_test_level == level) {
116 hibernation_debug_sleep();
117 return 1;
118 }
119 return 0;
120}
121#else /* !CONFIG_PM_DEBUG */
122static int hibernation_test(int level) { return 0; }
123#endif /* !CONFIG_PM_DEBUG */
124
125/**
126 * platform_begin - Call platform to start hibernation.
127 * @platform_mode: Whether or not to use the platform driver.
128 */
129static int platform_begin(int platform_mode)
130{
131 return (platform_mode && hibernation_ops) ?
132 hibernation_ops->begin(PMSG_FREEZE) : 0;
133}
134
135/**
136 * platform_end - Call platform to finish transition to the working state.
137 * @platform_mode: Whether or not to use the platform driver.
138 */
139static void platform_end(int platform_mode)
140{
141 if (platform_mode && hibernation_ops)
142 hibernation_ops->end();
143}
144
145/**
146 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
147 * @platform_mode: Whether or not to use the platform driver.
148 *
149 * Use the platform driver to prepare the system for creating a hibernate image,
150 * if so configured, and return an error code if that fails.
151 */
152
153static int platform_pre_snapshot(int platform_mode)
154{
155 return (platform_mode && hibernation_ops) ?
156 hibernation_ops->pre_snapshot() : 0;
157}
158
159/**
160 * platform_leave - Call platform to prepare a transition to the working state.
161 * @platform_mode: Whether or not to use the platform driver.
162 *
163 * Use the platform driver prepare to prepare the machine for switching to the
164 * normal mode of operation.
165 *
166 * This routine is called on one CPU with interrupts disabled.
167 */
168static void platform_leave(int platform_mode)
169{
170 if (platform_mode && hibernation_ops)
171 hibernation_ops->leave();
172}
173
174/**
175 * platform_finish - Call platform to switch the system to the working state.
176 * @platform_mode: Whether or not to use the platform driver.
177 *
178 * Use the platform driver to switch the machine to the normal mode of
179 * operation.
180 *
181 * This routine must be called after platform_prepare().
182 */
183static void platform_finish(int platform_mode)
184{
185 if (platform_mode && hibernation_ops)
186 hibernation_ops->finish();
187}
188
189/**
190 * platform_pre_restore - Prepare for hibernate image restoration.
191 * @platform_mode: Whether or not to use the platform driver.
192 *
193 * Use the platform driver to prepare the system for resume from a hibernation
194 * image.
195 *
196 * If the restore fails after this function has been called,
197 * platform_restore_cleanup() must be called.
198 */
199static int platform_pre_restore(int platform_mode)
200{
201 return (platform_mode && hibernation_ops) ?
202 hibernation_ops->pre_restore() : 0;
203}
204
205/**
206 * platform_restore_cleanup - Switch to the working state after failing restore.
207 * @platform_mode: Whether or not to use the platform driver.
208 *
209 * Use the platform driver to switch the system to the normal mode of operation
210 * after a failing restore.
211 *
212 * If platform_pre_restore() has been called before the failing restore, this
213 * function must be called too, regardless of the result of
214 * platform_pre_restore().
215 */
216static void platform_restore_cleanup(int platform_mode)
217{
218 if (platform_mode && hibernation_ops)
219 hibernation_ops->restore_cleanup();
220}
221
222/**
223 * platform_recover - Recover from a failure to suspend devices.
224 * @platform_mode: Whether or not to use the platform driver.
225 */
226static void platform_recover(int platform_mode)
227{
228 if (platform_mode && hibernation_ops && hibernation_ops->recover)
229 hibernation_ops->recover();
230}
231
232/**
233 * swsusp_show_speed - Print time elapsed between two events during hibernation.
234 * @start: Starting event.
235 * @stop: Final event.
236 * @nr_pages: Number of memory pages processed between @start and @stop.
237 * @msg: Additional diagnostic message to print.
238 */
239void swsusp_show_speed(ktime_t start, ktime_t stop,
240 unsigned nr_pages, char *msg)
241{
242 ktime_t diff;
243 u64 elapsed_centisecs64;
244 unsigned int centisecs;
245 unsigned int k;
246 unsigned int kps;
247
248 diff = ktime_sub(stop, start);
249 elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
250 centisecs = elapsed_centisecs64;
251 if (centisecs == 0)
252 centisecs = 1; /* avoid div-by-zero */
253 k = nr_pages * (PAGE_SIZE / 1024);
254 kps = (k * 100) / centisecs;
255 pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
256 msg, k, centisecs / 100, centisecs % 100, kps / 1000,
257 (kps % 1000) / 10);
258}
259
260__weak int arch_resume_nosmt(void)
261{
262 return 0;
263}
264
265/**
266 * create_image - Create a hibernation image.
267 * @platform_mode: Whether or not to use the platform driver.
268 *
269 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
270 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
271 *
272 * Control reappears in this routine after the subsequent restore.
273 */
274static int create_image(int platform_mode)
275{
276 int error;
277
278 error = dpm_suspend_end(PMSG_FREEZE);
279 if (error) {
280 pr_err("Some devices failed to power down, aborting hibernation\n");
281 return error;
282 }
283
284 error = platform_pre_snapshot(platform_mode);
285 if (error || hibernation_test(TEST_PLATFORM))
286 goto Platform_finish;
287
288 error = suspend_disable_secondary_cpus();
289 if (error || hibernation_test(TEST_CPUS))
290 goto Enable_cpus;
291
292 local_irq_disable();
293
294 system_state = SYSTEM_SUSPEND;
295
296 error = syscore_suspend();
297 if (error) {
298 pr_err("Some system devices failed to power down, aborting hibernation\n");
299 goto Enable_irqs;
300 }
301
302 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
303 goto Power_up;
304
305 in_suspend = 1;
306 save_processor_state();
307 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
308 error = swsusp_arch_suspend();
309 /* Restore control flow magically appears here */
310 restore_processor_state();
311 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
312 if (error)
313 pr_err("Error %d creating hibernation image\n", error);
314
315 if (!in_suspend) {
316 events_check_enabled = false;
317 clear_free_pages();
318 }
319
320 platform_leave(platform_mode);
321
322 Power_up:
323 syscore_resume();
324
325 Enable_irqs:
326 system_state = SYSTEM_RUNNING;
327 local_irq_enable();
328
329 Enable_cpus:
330 suspend_enable_secondary_cpus();
331
332 /* Allow architectures to do nosmt-specific post-resume dances */
333 if (!in_suspend)
334 error = arch_resume_nosmt();
335
336 Platform_finish:
337 platform_finish(platform_mode);
338
339 dpm_resume_start(in_suspend ?
340 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
341
342 return error;
343}
344
345/**
346 * hibernation_snapshot - Quiesce devices and create a hibernation image.
347 * @platform_mode: If set, use platform driver to prepare for the transition.
348 *
349 * This routine must be called with system_transition_mutex held.
350 */
351int hibernation_snapshot(int platform_mode)
352{
353 pm_message_t msg;
354 int error;
355
356 pm_suspend_clear_flags();
357 error = platform_begin(platform_mode);
358 if (error)
359 goto Close;
360
361 /* Preallocate image memory before shutting down devices. */
362 error = hibernate_preallocate_memory();
363 if (error)
364 goto Close;
365
366 error = freeze_kernel_threads();
367 if (error)
368 goto Cleanup;
369
370 if (hibernation_test(TEST_FREEZER)) {
371
372 /*
373 * Indicate to the caller that we are returning due to a
374 * successful freezer test.
375 */
376 freezer_test_done = true;
377 goto Thaw;
378 }
379
380 error = dpm_prepare(PMSG_FREEZE);
381 if (error) {
382 dpm_complete(PMSG_RECOVER);
383 goto Thaw;
384 }
385
386 suspend_console();
387 pm_restrict_gfp_mask();
388
389 error = dpm_suspend(PMSG_FREEZE);
390
391 if (error || hibernation_test(TEST_DEVICES))
392 platform_recover(platform_mode);
393 else
394 error = create_image(platform_mode);
395
396 /*
397 * In the case that we call create_image() above, the control
398 * returns here (1) after the image has been created or the
399 * image creation has failed and (2) after a successful restore.
400 */
401
402 /* We may need to release the preallocated image pages here. */
403 if (error || !in_suspend)
404 swsusp_free();
405
406 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
407 dpm_resume(msg);
408
409 if (error || !in_suspend)
410 pm_restore_gfp_mask();
411
412 resume_console();
413 dpm_complete(msg);
414
415 Close:
416 platform_end(platform_mode);
417 return error;
418
419 Thaw:
420 thaw_kernel_threads();
421 Cleanup:
422 swsusp_free();
423 goto Close;
424}
425
426int __weak hibernate_resume_nonboot_cpu_disable(void)
427{
428 return suspend_disable_secondary_cpus();
429}
430
431/**
432 * resume_target_kernel - Restore system state from a hibernation image.
433 * @platform_mode: Whether or not to use the platform driver.
434 *
435 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
436 * contents of highmem that have not been restored yet from the image and run
437 * the low-level code that will restore the remaining contents of memory and
438 * switch to the just restored target kernel.
439 */
440static int resume_target_kernel(bool platform_mode)
441{
442 int error;
443
444 error = dpm_suspend_end(PMSG_QUIESCE);
445 if (error) {
446 pr_err("Some devices failed to power down, aborting resume\n");
447 return error;
448 }
449
450 error = platform_pre_restore(platform_mode);
451 if (error)
452 goto Cleanup;
453
454 error = hibernate_resume_nonboot_cpu_disable();
455 if (error)
456 goto Enable_cpus;
457
458 local_irq_disable();
459 system_state = SYSTEM_SUSPEND;
460
461 error = syscore_suspend();
462 if (error)
463 goto Enable_irqs;
464
465 save_processor_state();
466 error = restore_highmem();
467 if (!error) {
468 error = swsusp_arch_resume();
469 /*
470 * The code below is only ever reached in case of a failure.
471 * Otherwise, execution continues at the place where
472 * swsusp_arch_suspend() was called.
473 */
474 BUG_ON(!error);
475 /*
476 * This call to restore_highmem() reverts the changes made by
477 * the previous one.
478 */
479 restore_highmem();
480 }
481 /*
482 * The only reason why swsusp_arch_resume() can fail is memory being
483 * very tight, so we have to free it as soon as we can to avoid
484 * subsequent failures.
485 */
486 swsusp_free();
487 restore_processor_state();
488 touch_softlockup_watchdog();
489
490 syscore_resume();
491
492 Enable_irqs:
493 system_state = SYSTEM_RUNNING;
494 local_irq_enable();
495
496 Enable_cpus:
497 suspend_enable_secondary_cpus();
498
499 Cleanup:
500 platform_restore_cleanup(platform_mode);
501
502 dpm_resume_start(PMSG_RECOVER);
503
504 return error;
505}
506
507/**
508 * hibernation_restore - Quiesce devices and restore from a hibernation image.
509 * @platform_mode: If set, use platform driver to prepare for the transition.
510 *
511 * This routine must be called with system_transition_mutex held. If it is
512 * successful, control reappears in the restored target kernel in
513 * hibernation_snapshot().
514 */
515int hibernation_restore(int platform_mode)
516{
517 int error;
518
519 pm_prepare_console();
520 suspend_console();
521 pm_restrict_gfp_mask();
522 error = dpm_suspend_start(PMSG_QUIESCE);
523 if (!error) {
524 error = resume_target_kernel(platform_mode);
525 /*
526 * The above should either succeed and jump to the new kernel,
527 * or return with an error. Otherwise things are just
528 * undefined, so let's be paranoid.
529 */
530 BUG_ON(!error);
531 }
532 dpm_resume_end(PMSG_RECOVER);
533 pm_restore_gfp_mask();
534 resume_console();
535 pm_restore_console();
536 return error;
537}
538
539/**
540 * hibernation_platform_enter - Power off the system using the platform driver.
541 */
542int hibernation_platform_enter(void)
543{
544 int error;
545
546 if (!hibernation_ops)
547 return -ENOSYS;
548
549 /*
550 * We have cancelled the power transition by running
551 * hibernation_ops->finish() before saving the image, so we should let
552 * the firmware know that we're going to enter the sleep state after all
553 */
554 error = hibernation_ops->begin(PMSG_HIBERNATE);
555 if (error)
556 goto Close;
557
558 entering_platform_hibernation = true;
559 suspend_console();
560 error = dpm_suspend_start(PMSG_HIBERNATE);
561 if (error) {
562 if (hibernation_ops->recover)
563 hibernation_ops->recover();
564 goto Resume_devices;
565 }
566
567 error = dpm_suspend_end(PMSG_HIBERNATE);
568 if (error)
569 goto Resume_devices;
570
571 error = hibernation_ops->prepare();
572 if (error)
573 goto Platform_finish;
574
575 error = suspend_disable_secondary_cpus();
576 if (error)
577 goto Enable_cpus;
578
579 local_irq_disable();
580 system_state = SYSTEM_SUSPEND;
581 syscore_suspend();
582 if (pm_wakeup_pending()) {
583 error = -EAGAIN;
584 goto Power_up;
585 }
586
587 hibernation_ops->enter();
588 /* We should never get here */
589 while (1);
590
591 Power_up:
592 syscore_resume();
593 system_state = SYSTEM_RUNNING;
594 local_irq_enable();
595
596 Enable_cpus:
597 suspend_enable_secondary_cpus();
598
599 Platform_finish:
600 hibernation_ops->finish();
601
602 dpm_resume_start(PMSG_RESTORE);
603
604 Resume_devices:
605 entering_platform_hibernation = false;
606 dpm_resume_end(PMSG_RESTORE);
607 resume_console();
608
609 Close:
610 hibernation_ops->end();
611
612 return error;
613}
614
615/**
616 * power_down - Shut the machine down for hibernation.
617 *
618 * Use the platform driver, if configured, to put the system into the sleep
619 * state corresponding to hibernation, or try to power it off or reboot,
620 * depending on the value of hibernation_mode.
621 */
622static void power_down(void)
623{
624#ifdef CONFIG_SUSPEND
625 int error;
626
627 if (hibernation_mode == HIBERNATION_SUSPEND) {
628 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
629 if (error) {
630 hibernation_mode = hibernation_ops ?
631 HIBERNATION_PLATFORM :
632 HIBERNATION_SHUTDOWN;
633 } else {
634 /* Restore swap signature. */
635 error = swsusp_unmark();
636 if (error)
637 pr_err("Swap will be unusable! Try swapon -a.\n");
638
639 return;
640 }
641 }
642#endif
643
644 switch (hibernation_mode) {
645 case HIBERNATION_REBOOT:
646 kernel_restart(NULL);
647 break;
648 case HIBERNATION_PLATFORM:
649 hibernation_platform_enter();
650 /* Fall through */
651 case HIBERNATION_SHUTDOWN:
652 if (pm_power_off)
653 kernel_power_off();
654 break;
655 }
656 kernel_halt();
657 /*
658 * Valid image is on the disk, if we continue we risk serious data
659 * corruption after resume.
660 */
661 pr_crit("Power down manually\n");
662 while (1)
663 cpu_relax();
664}
665
666static int load_image_and_restore(void)
667{
668 int error;
669 unsigned int flags;
670
671 pm_pr_dbg("Loading hibernation image.\n");
672
673 lock_device_hotplug();
674 error = create_basic_memory_bitmaps();
675 if (error)
676 goto Unlock;
677
678 error = swsusp_read(&flags);
679 swsusp_close(FMODE_READ);
680 if (!error)
681 hibernation_restore(flags & SF_PLATFORM_MODE);
682
683 pr_err("Failed to load hibernation image, recovering.\n");
684 swsusp_free();
685 free_basic_memory_bitmaps();
686 Unlock:
687 unlock_device_hotplug();
688
689 return error;
690}
691
692/**
693 * hibernate - Carry out system hibernation, including saving the image.
694 */
695int hibernate(void)
696{
697 int error, nr_calls = 0;
698 bool snapshot_test = false;
699
700 if (!hibernation_available()) {
701 pm_pr_dbg("Hibernation not available.\n");
702 return -EPERM;
703 }
704
705 lock_system_sleep();
706 /* The snapshot device should not be opened while we're running */
707 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
708 error = -EBUSY;
709 goto Unlock;
710 }
711
712 pr_info("hibernation entry\n");
713 pm_prepare_console();
714 error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
715 if (error) {
716 nr_calls--;
717 goto Exit;
718 }
719
720 ksys_sync_helper();
721
722 error = freeze_processes();
723 if (error)
724 goto Exit;
725
726 lock_device_hotplug();
727 /* Allocate memory management structures */
728 error = create_basic_memory_bitmaps();
729 if (error)
730 goto Thaw;
731
732 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
733 if (error || freezer_test_done)
734 goto Free_bitmaps;
735
736 if (in_suspend) {
737 unsigned int flags = 0;
738
739 if (hibernation_mode == HIBERNATION_PLATFORM)
740 flags |= SF_PLATFORM_MODE;
741 if (nocompress)
742 flags |= SF_NOCOMPRESS_MODE;
743 else
744 flags |= SF_CRC32_MODE;
745
746 pm_pr_dbg("Writing image.\n");
747 error = swsusp_write(flags);
748 swsusp_free();
749 if (!error) {
750 if (hibernation_mode == HIBERNATION_TEST_RESUME)
751 snapshot_test = true;
752 else
753 power_down();
754 }
755 in_suspend = 0;
756 pm_restore_gfp_mask();
757 } else {
758 pm_pr_dbg("Image restored successfully.\n");
759 }
760
761 Free_bitmaps:
762 free_basic_memory_bitmaps();
763 Thaw:
764 unlock_device_hotplug();
765 if (snapshot_test) {
766 pm_pr_dbg("Checking hibernation image\n");
767 error = swsusp_check();
768 if (!error)
769 error = load_image_and_restore();
770 }
771 thaw_processes();
772
773 /* Don't bother checking whether freezer_test_done is true */
774 freezer_test_done = false;
775 Exit:
776 __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
777 pm_restore_console();
778 atomic_inc(&snapshot_device_available);
779 Unlock:
780 unlock_system_sleep();
781 pr_info("hibernation exit\n");
782
783 return error;
784}
785
786
787/**
788 * software_resume - Resume from a saved hibernation image.
789 *
790 * This routine is called as a late initcall, when all devices have been
791 * discovered and initialized already.
792 *
793 * The image reading code is called to see if there is a hibernation image
794 * available for reading. If that is the case, devices are quiesced and the
795 * contents of memory is restored from the saved image.
796 *
797 * If this is successful, control reappears in the restored target kernel in
798 * hibernation_snapshot() which returns to hibernate(). Otherwise, the routine
799 * attempts to recover gracefully and make the kernel return to the normal mode
800 * of operation.
801 */
802static int software_resume(void)
803{
804 int error, nr_calls = 0;
805
806 /*
807 * If the user said "noresume".. bail out early.
808 */
809 if (noresume || !hibernation_available())
810 return 0;
811
812 /*
813 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
814 * is configured into the kernel. Since the regular hibernate
815 * trigger path is via sysfs which takes a buffer mutex before
816 * calling hibernate functions (which take system_transition_mutex)
817 * this can cause lockdep to complain about a possible ABBA deadlock
818 * which cannot happen since we're in the boot code here and
819 * sysfs can't be invoked yet. Therefore, we use a subclass
820 * here to avoid lockdep complaining.
821 */
822 mutex_lock_nested(&system_transition_mutex, SINGLE_DEPTH_NESTING);
823
824 if (swsusp_resume_device)
825 goto Check_image;
826
827 if (!strlen(resume_file)) {
828 error = -ENOENT;
829 goto Unlock;
830 }
831
832 pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
833
834 if (resume_delay) {
835 pr_info("Waiting %dsec before reading resume device ...\n",
836 resume_delay);
837 ssleep(resume_delay);
838 }
839
840 /* Check if the device is there */
841 swsusp_resume_device = name_to_dev_t(resume_file);
842
843 /*
844 * name_to_dev_t is ineffective to verify parition if resume_file is in
845 * integer format. (e.g. major:minor)
846 */
847 if (isdigit(resume_file[0]) && resume_wait) {
848 int partno;
849 while (!get_gendisk(swsusp_resume_device, &partno))
850 msleep(10);
851 }
852
853 if (!swsusp_resume_device) {
854 /*
855 * Some device discovery might still be in progress; we need
856 * to wait for this to finish.
857 */
858 wait_for_device_probe();
859
860 if (resume_wait) {
861 while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
862 msleep(10);
863 async_synchronize_full();
864 }
865
866 swsusp_resume_device = name_to_dev_t(resume_file);
867 if (!swsusp_resume_device) {
868 error = -ENODEV;
869 goto Unlock;
870 }
871 }
872
873 Check_image:
874 pm_pr_dbg("Hibernation image partition %d:%d present\n",
875 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
876
877 pm_pr_dbg("Looking for hibernation image.\n");
878 error = swsusp_check();
879 if (error)
880 goto Unlock;
881
882 /* The snapshot device should not be opened while we're running */
883 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
884 error = -EBUSY;
885 swsusp_close(FMODE_READ);
886 goto Unlock;
887 }
888
889 pr_info("resume from hibernation\n");
890 pm_prepare_console();
891 error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
892 if (error) {
893 nr_calls--;
894 goto Close_Finish;
895 }
896
897 pm_pr_dbg("Preparing processes for restore.\n");
898 error = freeze_processes();
899 if (error)
900 goto Close_Finish;
901 error = load_image_and_restore();
902 thaw_processes();
903 Finish:
904 __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
905 pm_restore_console();
906 pr_info("resume from hibernation failed (%d)\n", error);
907 atomic_inc(&snapshot_device_available);
908 /* For success case, the suspend path will release the lock */
909 Unlock:
910 mutex_unlock(&system_transition_mutex);
911 pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
912 return error;
913 Close_Finish:
914 swsusp_close(FMODE_READ);
915 goto Finish;
916}
917
918late_initcall_sync(software_resume);
919
920
921static const char * const hibernation_modes[] = {
922 [HIBERNATION_PLATFORM] = "platform",
923 [HIBERNATION_SHUTDOWN] = "shutdown",
924 [HIBERNATION_REBOOT] = "reboot",
925#ifdef CONFIG_SUSPEND
926 [HIBERNATION_SUSPEND] = "suspend",
927#endif
928 [HIBERNATION_TEST_RESUME] = "test_resume",
929};
930
931/*
932 * /sys/power/disk - Control hibernation mode.
933 *
934 * Hibernation can be handled in several ways. There are a few different ways
935 * to put the system into the sleep state: using the platform driver (e.g. ACPI
936 * or other hibernation_ops), powering it off or rebooting it (for testing
937 * mostly).
938 *
939 * The sysfs file /sys/power/disk provides an interface for selecting the
940 * hibernation mode to use. Reading from this file causes the available modes
941 * to be printed. There are 3 modes that can be supported:
942 *
943 * 'platform'
944 * 'shutdown'
945 * 'reboot'
946 *
947 * If a platform hibernation driver is in use, 'platform' will be supported
948 * and will be used by default. Otherwise, 'shutdown' will be used by default.
949 * The selected option (i.e. the one corresponding to the current value of
950 * hibernation_mode) is enclosed by a square bracket.
951 *
952 * To select a given hibernation mode it is necessary to write the mode's
953 * string representation (as returned by reading from /sys/power/disk) back
954 * into /sys/power/disk.
955 */
956
957static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
958 char *buf)
959{
960 int i;
961 char *start = buf;
962
963 if (!hibernation_available())
964 return sprintf(buf, "[disabled]\n");
965
966 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
967 if (!hibernation_modes[i])
968 continue;
969 switch (i) {
970 case HIBERNATION_SHUTDOWN:
971 case HIBERNATION_REBOOT:
972#ifdef CONFIG_SUSPEND
973 case HIBERNATION_SUSPEND:
974#endif
975 case HIBERNATION_TEST_RESUME:
976 break;
977 case HIBERNATION_PLATFORM:
978 if (hibernation_ops)
979 break;
980 /* not a valid mode, continue with loop */
981 continue;
982 }
983 if (i == hibernation_mode)
984 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
985 else
986 buf += sprintf(buf, "%s ", hibernation_modes[i]);
987 }
988 buf += sprintf(buf, "\n");
989 return buf-start;
990}
991
992static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
993 const char *buf, size_t n)
994{
995 int error = 0;
996 int i;
997 int len;
998 char *p;
999 int mode = HIBERNATION_INVALID;
1000
1001 if (!hibernation_available())
1002 return -EPERM;
1003
1004 p = memchr(buf, '\n', n);
1005 len = p ? p - buf : n;
1006
1007 lock_system_sleep();
1008 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1009 if (len == strlen(hibernation_modes[i])
1010 && !strncmp(buf, hibernation_modes[i], len)) {
1011 mode = i;
1012 break;
1013 }
1014 }
1015 if (mode != HIBERNATION_INVALID) {
1016 switch (mode) {
1017 case HIBERNATION_SHUTDOWN:
1018 case HIBERNATION_REBOOT:
1019#ifdef CONFIG_SUSPEND
1020 case HIBERNATION_SUSPEND:
1021#endif
1022 case HIBERNATION_TEST_RESUME:
1023 hibernation_mode = mode;
1024 break;
1025 case HIBERNATION_PLATFORM:
1026 if (hibernation_ops)
1027 hibernation_mode = mode;
1028 else
1029 error = -EINVAL;
1030 }
1031 } else
1032 error = -EINVAL;
1033
1034 if (!error)
1035 pm_pr_dbg("Hibernation mode set to '%s'\n",
1036 hibernation_modes[mode]);
1037 unlock_system_sleep();
1038 return error ? error : n;
1039}
1040
1041power_attr(disk);
1042
1043static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1044 char *buf)
1045{
1046 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
1047 MINOR(swsusp_resume_device));
1048}
1049
1050static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1051 const char *buf, size_t n)
1052{
1053 dev_t res;
1054 int len = n;
1055 char *name;
1056
1057 if (len && buf[len-1] == '\n')
1058 len--;
1059 name = kstrndup(buf, len, GFP_KERNEL);
1060 if (!name)
1061 return -ENOMEM;
1062
1063 res = name_to_dev_t(name);
1064 kfree(name);
1065 if (!res)
1066 return -EINVAL;
1067
1068 lock_system_sleep();
1069 swsusp_resume_device = res;
1070 unlock_system_sleep();
1071 pm_pr_dbg("Configured resume from disk to %u\n", swsusp_resume_device);
1072 noresume = 0;
1073 software_resume();
1074 return n;
1075}
1076
1077power_attr(resume);
1078
1079static ssize_t resume_offset_show(struct kobject *kobj,
1080 struct kobj_attribute *attr, char *buf)
1081{
1082 return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1083}
1084
1085static ssize_t resume_offset_store(struct kobject *kobj,
1086 struct kobj_attribute *attr, const char *buf,
1087 size_t n)
1088{
1089 unsigned long long offset;
1090 int rc;
1091
1092 rc = kstrtoull(buf, 0, &offset);
1093 if (rc)
1094 return rc;
1095 swsusp_resume_block = offset;
1096
1097 return n;
1098}
1099
1100power_attr(resume_offset);
1101
1102static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1103 char *buf)
1104{
1105 return sprintf(buf, "%lu\n", image_size);
1106}
1107
1108static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1109 const char *buf, size_t n)
1110{
1111 unsigned long size;
1112
1113 if (sscanf(buf, "%lu", &size) == 1) {
1114 image_size = size;
1115 return n;
1116 }
1117
1118 return -EINVAL;
1119}
1120
1121power_attr(image_size);
1122
1123static ssize_t reserved_size_show(struct kobject *kobj,
1124 struct kobj_attribute *attr, char *buf)
1125{
1126 return sprintf(buf, "%lu\n", reserved_size);
1127}
1128
1129static ssize_t reserved_size_store(struct kobject *kobj,
1130 struct kobj_attribute *attr,
1131 const char *buf, size_t n)
1132{
1133 unsigned long size;
1134
1135 if (sscanf(buf, "%lu", &size) == 1) {
1136 reserved_size = size;
1137 return n;
1138 }
1139
1140 return -EINVAL;
1141}
1142
1143power_attr(reserved_size);
1144
1145static struct attribute * g[] = {
1146 &disk_attr.attr,
1147 &resume_offset_attr.attr,
1148 &resume_attr.attr,
1149 &image_size_attr.attr,
1150 &reserved_size_attr.attr,
1151 NULL,
1152};
1153
1154
1155static const struct attribute_group attr_group = {
1156 .attrs = g,
1157};
1158
1159
1160static int __init pm_disk_init(void)
1161{
1162 return sysfs_create_group(power_kobj, &attr_group);
1163}
1164
1165core_initcall(pm_disk_init);
1166
1167
1168static int __init resume_setup(char *str)
1169{
1170 if (noresume)
1171 return 1;
1172
1173 strncpy( resume_file, str, 255 );
1174 return 1;
1175}
1176
1177static int __init resume_offset_setup(char *str)
1178{
1179 unsigned long long offset;
1180
1181 if (noresume)
1182 return 1;
1183
1184 if (sscanf(str, "%llu", &offset) == 1)
1185 swsusp_resume_block = offset;
1186
1187 return 1;
1188}
1189
1190static int __init hibernate_setup(char *str)
1191{
1192 if (!strncmp(str, "noresume", 8)) {
1193 noresume = 1;
1194 } else if (!strncmp(str, "nocompress", 10)) {
1195 nocompress = 1;
1196 } else if (!strncmp(str, "no", 2)) {
1197 noresume = 1;
1198 nohibernate = 1;
1199 } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1200 && !strncmp(str, "protect_image", 13)) {
1201 enable_restore_image_protection();
1202 }
1203 return 1;
1204}
1205
1206static int __init noresume_setup(char *str)
1207{
1208 noresume = 1;
1209 return 1;
1210}
1211
1212static int __init resumewait_setup(char *str)
1213{
1214 resume_wait = 1;
1215 return 1;
1216}
1217
1218static int __init resumedelay_setup(char *str)
1219{
1220 int rc = kstrtouint(str, 0, &resume_delay);
1221
1222 if (rc)
1223 return rc;
1224 return 1;
1225}
1226
1227static int __init nohibernate_setup(char *str)
1228{
1229 noresume = 1;
1230 nohibernate = 1;
1231 return 1;
1232}
1233
1234__setup("noresume", noresume_setup);
1235__setup("resume_offset=", resume_offset_setup);
1236__setup("resume=", resume_setup);
1237__setup("hibernate=", hibernate_setup);
1238__setup("resumewait", resumewait_setup);
1239__setup("resumedelay=", resumedelay_setup);
1240__setup("nohibernate", nohibernate_setup);