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