1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
4 *
5 * Copyright (c) 2003 Patrick Mochel
6 * Copyright (c) 2003 Open Source Development Lab
7 * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
8 * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
9 * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
10 */
11
12#define pr_fmt(fmt) "PM: hibernation: " fmt
13
14#include <crypto/acompress.h>
15#include <linux/blkdev.h>
16#include <linux/export.h>
17#include <linux/suspend.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/ktime.h>
34#include <linux/security.h>
35#include <linux/secretmem.h>
36#include <trace/events/power.h>
37
38#include "power.h"
39
40
41static int nocompress;
42static int noresume;
43static int nohibernate;
44static int resume_wait;
45static unsigned int resume_delay;
46static char resume_file[256] = CONFIG_PM_STD_PARTITION;
47dev_t swsusp_resume_device;
48sector_t swsusp_resume_block;
49__visible int in_suspend __nosavedata;
50
51static char hibernate_compressor[CRYPTO_MAX_ALG_NAME] = CONFIG_HIBERNATION_DEF_COMP;
52
53/*
54 * Compression/decompression algorithm to be used while saving/loading
55 * image to/from disk. This would later be used in 'kernel/power/swap.c'
56 * to allocate comp streams.
57 */
58char hib_comp_algo[CRYPTO_MAX_ALG_NAME];
59
60enum {
61 HIBERNATION_INVALID,
62 HIBERNATION_PLATFORM,
63 HIBERNATION_SHUTDOWN,
64 HIBERNATION_REBOOT,
65#ifdef CONFIG_SUSPEND
66 HIBERNATION_SUSPEND,
67#endif
68 HIBERNATION_TEST_RESUME,
69 /* keep last */
70 __HIBERNATION_AFTER_LAST
71};
72#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
73#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
74
75static int hibernation_mode = HIBERNATION_SHUTDOWN;
76
77bool freezer_test_done;
78
79static const struct platform_hibernation_ops *hibernation_ops;
80
81static atomic_t hibernate_atomic = ATOMIC_INIT(1);
82
83#ifdef CONFIG_SUSPEND
84/**
85 * pm_hibernation_mode_is_suspend - Check if hibernation has been set to suspend
86 */
87bool pm_hibernation_mode_is_suspend(void)
88{
89 return hibernation_mode == HIBERNATION_SUSPEND;
90}
91EXPORT_SYMBOL_GPL(pm_hibernation_mode_is_suspend);
92#endif
93
94bool hibernate_acquire(void)
95{
96 return atomic_add_unless(v: &hibernate_atomic, a: -1, u: 0);
97}
98
99void hibernate_release(void)
100{
101 atomic_inc(v: &hibernate_atomic);
102}
103
104bool hibernation_in_progress(void)
105{
106 return !atomic_read(v: &hibernate_atomic);
107}
108
109bool hibernation_available(void)
110{
111 return nohibernate == 0 &&
112 !security_locked_down(what: LOCKDOWN_HIBERNATION) &&
113 !secretmem_active() && !cxl_mem_active();
114}
115
116/**
117 * hibernation_set_ops - Set the global hibernate operations.
118 * @ops: Hibernation operations to use in subsequent hibernation transitions.
119 */
120void hibernation_set_ops(const struct platform_hibernation_ops *ops)
121{
122 unsigned int sleep_flags;
123
124 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
125 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
126 && ops->restore_cleanup && ops->leave)) {
127 WARN_ON(1);
128 return;
129 }
130
131 sleep_flags = lock_system_sleep();
132
133 hibernation_ops = ops;
134 if (ops)
135 hibernation_mode = HIBERNATION_PLATFORM;
136 else if (hibernation_mode == HIBERNATION_PLATFORM)
137 hibernation_mode = HIBERNATION_SHUTDOWN;
138
139 unlock_system_sleep(sleep_flags);
140}
141EXPORT_SYMBOL_GPL(hibernation_set_ops);
142
143static bool entering_platform_hibernation;
144
145bool system_entering_hibernation(void)
146{
147 return entering_platform_hibernation;
148}
149EXPORT_SYMBOL(system_entering_hibernation);
150
151#ifdef CONFIG_PM_DEBUG
152static unsigned int pm_test_delay = 5;
153module_param(pm_test_delay, uint, 0644);
154MODULE_PARM_DESC(pm_test_delay,
155 "Number of seconds to wait before resuming from hibernation test");
156static void hibernation_debug_sleep(void)
157{
158 pr_info("hibernation debug: Waiting for %d second(s).\n",
159 pm_test_delay);
160 mdelay(pm_test_delay * 1000);
161}
162
163static int hibernation_test(int level)
164{
165 if (pm_test_level == level) {
166 hibernation_debug_sleep();
167 return 1;
168 }
169 return 0;
170}
171#else /* !CONFIG_PM_DEBUG */
172static int hibernation_test(int level) { return 0; }
173#endif /* !CONFIG_PM_DEBUG */
174
175/**
176 * platform_begin - Call platform to start hibernation.
177 * @platform_mode: Whether or not to use the platform driver.
178 */
179static int platform_begin(int platform_mode)
180{
181 return (platform_mode && hibernation_ops) ?
182 hibernation_ops->begin(PMSG_FREEZE) : 0;
183}
184
185/**
186 * platform_end - Call platform to finish transition to the working state.
187 * @platform_mode: Whether or not to use the platform driver.
188 */
189static void platform_end(int platform_mode)
190{
191 if (platform_mode && hibernation_ops)
192 hibernation_ops->end();
193}
194
195/**
196 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
197 * @platform_mode: Whether or not to use the platform driver.
198 *
199 * Use the platform driver to prepare the system for creating a hibernate image,
200 * if so configured, and return an error code if that fails.
201 */
202
203static int platform_pre_snapshot(int platform_mode)
204{
205 return (platform_mode && hibernation_ops) ?
206 hibernation_ops->pre_snapshot() : 0;
207}
208
209/**
210 * platform_leave - Call platform to prepare a transition to the working state.
211 * @platform_mode: Whether or not to use the platform driver.
212 *
213 * Use the platform driver prepare to prepare the machine for switching to the
214 * normal mode of operation.
215 *
216 * This routine is called on one CPU with interrupts disabled.
217 */
218static void platform_leave(int platform_mode)
219{
220 if (platform_mode && hibernation_ops)
221 hibernation_ops->leave();
222}
223
224/**
225 * platform_finish - Call platform to switch the system to the working state.
226 * @platform_mode: Whether or not to use the platform driver.
227 *
228 * Use the platform driver to switch the machine to the normal mode of
229 * operation.
230 *
231 * This routine must be called after platform_prepare().
232 */
233static void platform_finish(int platform_mode)
234{
235 if (platform_mode && hibernation_ops)
236 hibernation_ops->finish();
237}
238
239/**
240 * platform_pre_restore - Prepare for hibernate image restoration.
241 * @platform_mode: Whether or not to use the platform driver.
242 *
243 * Use the platform driver to prepare the system for resume from a hibernation
244 * image.
245 *
246 * If the restore fails after this function has been called,
247 * platform_restore_cleanup() must be called.
248 */
249static int platform_pre_restore(int platform_mode)
250{
251 return (platform_mode && hibernation_ops) ?
252 hibernation_ops->pre_restore() : 0;
253}
254
255/**
256 * platform_restore_cleanup - Switch to the working state after failing restore.
257 * @platform_mode: Whether or not to use the platform driver.
258 *
259 * Use the platform driver to switch the system to the normal mode of operation
260 * after a failing restore.
261 *
262 * If platform_pre_restore() has been called before the failing restore, this
263 * function must be called too, regardless of the result of
264 * platform_pre_restore().
265 */
266static void platform_restore_cleanup(int platform_mode)
267{
268 if (platform_mode && hibernation_ops)
269 hibernation_ops->restore_cleanup();
270}
271
272/**
273 * platform_recover - Recover from a failure to suspend devices.
274 * @platform_mode: Whether or not to use the platform driver.
275 */
276static void platform_recover(int platform_mode)
277{
278 if (platform_mode && hibernation_ops && hibernation_ops->recover)
279 hibernation_ops->recover();
280}
281
282/**
283 * swsusp_show_speed - Print time elapsed between two events during hibernation.
284 * @start: Starting event.
285 * @stop: Final event.
286 * @nr_pages: Number of memory pages processed between @start and @stop.
287 * @msg: Additional diagnostic message to print.
288 */
289void swsusp_show_speed(ktime_t start, ktime_t stop,
290 unsigned nr_pages, char *msg)
291{
292 ktime_t diff;
293 u64 elapsed_centisecs64;
294 unsigned int centisecs;
295 unsigned int k;
296 unsigned int kps;
297
298 diff = ktime_sub(stop, start);
299 elapsed_centisecs64 = ktime_divns(kt: diff, div: 10*NSEC_PER_MSEC);
300 centisecs = elapsed_centisecs64;
301 if (centisecs == 0)
302 centisecs = 1; /* avoid div-by-zero */
303 k = nr_pages * (PAGE_SIZE / 1024);
304 kps = (k * 100) / centisecs;
305 pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
306 msg, k, centisecs / 100, centisecs % 100, kps / 1000,
307 (kps % 1000) / 10);
308}
309
310__weak int arch_resume_nosmt(void)
311{
312 return 0;
313}
314
315/**
316 * create_image - Create a hibernation image.
317 * @platform_mode: Whether or not to use the platform driver.
318 *
319 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
320 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
321 *
322 * Control reappears in this routine after the subsequent restore.
323 */
324static int create_image(int platform_mode)
325{
326 int error;
327
328 error = dpm_suspend_end(PMSG_FREEZE);
329 if (error) {
330 pr_err("Some devices failed to power down, aborting\n");
331 return error;
332 }
333
334 error = platform_pre_snapshot(platform_mode);
335 if (error || hibernation_test(level: TEST_PLATFORM))
336 goto Platform_finish;
337
338 error = pm_sleep_disable_secondary_cpus();
339 if (error || hibernation_test(level: TEST_CPUS))
340 goto Enable_cpus;
341
342 local_irq_disable();
343
344 system_state = SYSTEM_SUSPEND;
345
346 error = syscore_suspend();
347 if (error) {
348 pr_err("Some system devices failed to power down, aborting\n");
349 goto Enable_irqs;
350 }
351
352 if (hibernation_test(level: TEST_CORE) || pm_wakeup_pending())
353 goto Power_up;
354
355 in_suspend = 1;
356 save_processor_state();
357 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, start: true);
358 error = swsusp_arch_suspend();
359 /* Restore control flow magically appears here */
360 restore_processor_state();
361 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, start: false);
362 if (error)
363 pr_err("Error %d creating image\n", error);
364
365 if (!in_suspend) {
366 events_check_enabled = false;
367 clear_or_poison_free_pages();
368 }
369
370 platform_leave(platform_mode);
371
372 Power_up:
373 syscore_resume();
374
375 Enable_irqs:
376 system_state = SYSTEM_RUNNING;
377 local_irq_enable();
378
379 Enable_cpus:
380 pm_sleep_enable_secondary_cpus();
381
382 /* Allow architectures to do nosmt-specific post-resume dances */
383 if (!in_suspend)
384 error = arch_resume_nosmt();
385
386 Platform_finish:
387 platform_finish(platform_mode);
388
389 dpm_resume_start(state: in_suspend ?
390 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
391
392 return error;
393}
394
395static void shrink_shmem_memory(void)
396{
397 struct sysinfo info;
398 unsigned long nr_shmem_pages, nr_freed_pages;
399
400 si_meminfo(val: &info);
401 nr_shmem_pages = info.sharedram; /* current page count used for shmem */
402 /*
403 * The intent is to reclaim all shmem pages. Though shrink_all_memory() can
404 * only reclaim about half of them, it's enough for creating the hibernation
405 * image.
406 */
407 nr_freed_pages = shrink_all_memory(nr_pages: nr_shmem_pages);
408 pr_debug("requested to reclaim %lu shmem pages, actually freed %lu pages\n",
409 nr_shmem_pages, nr_freed_pages);
410}
411
412/**
413 * hibernation_snapshot - Quiesce devices and create a hibernation image.
414 * @platform_mode: If set, use platform driver to prepare for the transition.
415 *
416 * This routine must be called with system_transition_mutex held.
417 */
418int hibernation_snapshot(int platform_mode)
419{
420 pm_message_t msg;
421 int error;
422
423 pm_suspend_clear_flags();
424 error = platform_begin(platform_mode);
425 if (error)
426 goto Close;
427
428 /* Preallocate image memory before shutting down devices. */
429 error = hibernate_preallocate_memory();
430 if (error)
431 goto Close;
432
433 error = freeze_kernel_threads();
434 if (error)
435 goto Cleanup;
436
437 if (hibernation_test(level: TEST_FREEZER)) {
438
439 /*
440 * Indicate to the caller that we are returning due to a
441 * successful freezer test.
442 */
443 freezer_test_done = true;
444 goto Thaw;
445 }
446
447 error = dpm_prepare(PMSG_FREEZE);
448 if (error) {
449 dpm_complete(PMSG_RECOVER);
450 goto Thaw;
451 }
452
453 /*
454 * Device drivers may move lots of data to shmem in dpm_prepare(). The shmem
455 * pages will use lots of system memory, causing hibernation image creation
456 * fail due to insufficient free memory.
457 * This call is to force flush the shmem pages to swap disk and reclaim
458 * the system memory so that image creation can succeed.
459 */
460 shrink_shmem_memory();
461
462 console_suspend_all();
463 pm_restrict_gfp_mask();
464
465 error = dpm_suspend(PMSG_FREEZE);
466
467 if (error || hibernation_test(level: TEST_DEVICES))
468 platform_recover(platform_mode);
469 else
470 error = create_image(platform_mode);
471
472 /*
473 * In the case that we call create_image() above, the control
474 * returns here (1) after the image has been created or the
475 * image creation has failed and (2) after a successful restore.
476 */
477
478 /* We may need to release the preallocated image pages here. */
479 if (error || !in_suspend)
480 swsusp_free();
481
482 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
483 dpm_resume(state: msg);
484
485 if (error || !in_suspend)
486 pm_restore_gfp_mask();
487
488 console_resume_all();
489 dpm_complete(state: msg);
490
491 Close:
492 platform_end(platform_mode);
493 return error;
494
495 Thaw:
496 thaw_kernel_threads();
497 Cleanup:
498 swsusp_free();
499 goto Close;
500}
501
502int __weak hibernate_resume_nonboot_cpu_disable(void)
503{
504 return suspend_disable_secondary_cpus();
505}
506
507/**
508 * resume_target_kernel - Restore system state from a hibernation image.
509 * @platform_mode: Whether or not to use the platform driver.
510 *
511 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
512 * contents of highmem that have not been restored yet from the image and run
513 * the low-level code that will restore the remaining contents of memory and
514 * switch to the just restored target kernel.
515 */
516static int resume_target_kernel(bool platform_mode)
517{
518 int error;
519
520 error = dpm_suspend_end(PMSG_QUIESCE);
521 if (error) {
522 pr_err("Some devices failed to power down, aborting resume\n");
523 return error;
524 }
525
526 error = platform_pre_restore(platform_mode);
527 if (error)
528 goto Cleanup;
529
530 cpuidle_pause();
531
532 error = hibernate_resume_nonboot_cpu_disable();
533 if (error)
534 goto Enable_cpus;
535
536 local_irq_disable();
537 system_state = SYSTEM_SUSPEND;
538
539 error = syscore_suspend();
540 if (error)
541 goto Enable_irqs;
542
543 save_processor_state();
544 error = restore_highmem();
545 if (!error) {
546 error = swsusp_arch_resume();
547 /*
548 * The code below is only ever reached in case of a failure.
549 * Otherwise, execution continues at the place where
550 * swsusp_arch_suspend() was called.
551 */
552 BUG_ON(!error);
553 /*
554 * This call to restore_highmem() reverts the changes made by
555 * the previous one.
556 */
557 restore_highmem();
558 }
559 /*
560 * The only reason why swsusp_arch_resume() can fail is memory being
561 * very tight, so we have to free it as soon as we can to avoid
562 * subsequent failures.
563 */
564 swsusp_free();
565 restore_processor_state();
566 touch_softlockup_watchdog();
567
568 syscore_resume();
569
570 Enable_irqs:
571 system_state = SYSTEM_RUNNING;
572 local_irq_enable();
573
574 Enable_cpus:
575 pm_sleep_enable_secondary_cpus();
576
577 Cleanup:
578 platform_restore_cleanup(platform_mode);
579
580 dpm_resume_start(PMSG_RECOVER);
581
582 return error;
583}
584
585/**
586 * hibernation_restore - Quiesce devices and restore from a hibernation image.
587 * @platform_mode: If set, use platform driver to prepare for the transition.
588 *
589 * This routine must be called with system_transition_mutex held. If it is
590 * successful, control reappears in the restored target kernel in
591 * hibernation_snapshot().
592 */
593int hibernation_restore(int platform_mode)
594{
595 int error;
596
597 pm_prepare_console();
598 console_suspend_all();
599 error = dpm_suspend_start(PMSG_QUIESCE);
600 if (!error) {
601 error = resume_target_kernel(platform_mode);
602 /*
603 * The above should either succeed and jump to the new kernel,
604 * or return with an error. Otherwise things are just
605 * undefined, so let's be paranoid.
606 */
607 BUG_ON(!error);
608 }
609 dpm_resume_end(PMSG_RECOVER);
610 console_resume_all();
611 pm_restore_console();
612 return error;
613}
614
615/**
616 * hibernation_platform_enter - Power off the system using the platform driver.
617 */
618int hibernation_platform_enter(void)
619{
620 int error;
621
622 if (!hibernation_ops)
623 return -ENOSYS;
624
625 /*
626 * We have cancelled the power transition by running
627 * hibernation_ops->finish() before saving the image, so we should let
628 * the firmware know that we're going to enter the sleep state after all
629 */
630 error = hibernation_ops->begin(PMSG_HIBERNATE);
631 if (error)
632 goto Close;
633
634 entering_platform_hibernation = true;
635 console_suspend_all();
636 error = dpm_suspend_start(PMSG_HIBERNATE);
637 if (error) {
638 if (hibernation_ops->recover)
639 hibernation_ops->recover();
640 goto Resume_devices;
641 }
642
643 error = dpm_suspend_end(PMSG_HIBERNATE);
644 if (error)
645 goto Resume_devices;
646
647 error = hibernation_ops->prepare();
648 if (error)
649 goto Platform_finish;
650
651 error = pm_sleep_disable_secondary_cpus();
652 if (error)
653 goto Enable_cpus;
654
655 local_irq_disable();
656 system_state = SYSTEM_SUSPEND;
657
658 error = syscore_suspend();
659 if (error)
660 goto Enable_irqs;
661
662 if (pm_wakeup_pending()) {
663 error = -EAGAIN;
664 goto Power_up;
665 }
666
667 hibernation_ops->enter();
668 /* We should never get here */
669 while (1);
670
671 Power_up:
672 syscore_resume();
673 Enable_irqs:
674 system_state = SYSTEM_RUNNING;
675 local_irq_enable();
676
677 Enable_cpus:
678 pm_sleep_enable_secondary_cpus();
679
680 Platform_finish:
681 hibernation_ops->finish();
682
683 dpm_resume_start(PMSG_RESTORE);
684
685 Resume_devices:
686 entering_platform_hibernation = false;
687 dpm_resume_end(PMSG_RESTORE);
688 console_resume_all();
689
690 Close:
691 hibernation_ops->end();
692
693 return error;
694}
695
696/**
697 * power_down - Shut the machine down for hibernation.
698 *
699 * Use the platform driver, if configured, to put the system into the sleep
700 * state corresponding to hibernation, or try to power it off or reboot,
701 * depending on the value of hibernation_mode.
702 */
703static void power_down(void)
704{
705 int error;
706
707#ifdef CONFIG_SUSPEND
708 if (hibernation_mode == HIBERNATION_SUSPEND) {
709 pm_restore_gfp_mask();
710 error = suspend_devices_and_enter(state: mem_sleep_current);
711 if (!error)
712 goto exit;
713
714 hibernation_mode = hibernation_ops ? HIBERNATION_PLATFORM :
715 HIBERNATION_SHUTDOWN;
716 }
717#endif
718
719 switch (hibernation_mode) {
720 case HIBERNATION_REBOOT:
721 kernel_restart(NULL);
722 break;
723 case HIBERNATION_PLATFORM:
724 error = hibernation_platform_enter();
725 if (error == -EAGAIN || error == -EBUSY) {
726 events_check_enabled = false;
727 pr_info("Wakeup event detected during hibernation, rolling back.\n");
728 goto exit;
729 }
730 fallthrough;
731 case HIBERNATION_SHUTDOWN:
732 if (kernel_can_power_off()) {
733 entering_platform_hibernation = true;
734 kernel_power_off();
735 entering_platform_hibernation = false;
736 }
737 break;
738 }
739 kernel_halt();
740 /*
741 * Valid image is on the disk, if we continue we risk serious data
742 * corruption after resume.
743 */
744 pr_crit("Power down manually\n");
745 while (1)
746 cpu_relax();
747
748exit:
749 /* Match the pm_restore_gfp_mask() call in hibernate(). */
750 pm_restrict_gfp_mask();
751
752 /* Restore swap signature. */
753 error = swsusp_unmark();
754 if (error)
755 pr_err("Swap will be unusable! Try swapon -a.\n");
756}
757
758static int load_image_and_restore(void)
759{
760 int error;
761 unsigned int flags;
762
763 pm_pr_dbg("Loading hibernation image.\n");
764
765 lock_device_hotplug();
766 error = create_basic_memory_bitmaps();
767 if (error) {
768 swsusp_close();
769 goto Unlock;
770 }
771
772 error = swsusp_read(flags_p: &flags);
773 swsusp_close();
774 if (!error)
775 error = hibernation_restore(platform_mode: flags & SF_PLATFORM_MODE);
776
777 pr_err("Failed to load image, recovering.\n");
778 swsusp_free();
779 free_basic_memory_bitmaps();
780 Unlock:
781 unlock_device_hotplug();
782
783 return error;
784}
785
786#define COMPRESSION_ALGO_LZO "lzo"
787#define COMPRESSION_ALGO_LZ4 "lz4"
788
789/**
790 * hibernate - Carry out system hibernation, including saving the image.
791 */
792int hibernate(void)
793{
794 bool snapshot_test = false;
795 unsigned int sleep_flags;
796 int error;
797
798 if (!hibernation_available()) {
799 pm_pr_dbg("Hibernation not available.\n");
800 return -EPERM;
801 }
802
803 /*
804 * Query for the compression algorithm support if compression is enabled.
805 */
806 if (!nocompress) {
807 strscpy(hib_comp_algo, hibernate_compressor);
808 if (!crypto_has_acomp(alg_name: hib_comp_algo, type: 0, CRYPTO_ALG_ASYNC)) {
809 pr_err("%s compression is not available\n", hib_comp_algo);
810 return -EOPNOTSUPP;
811 }
812 }
813
814 sleep_flags = lock_system_sleep();
815 /* The snapshot device should not be opened while we're running */
816 if (!hibernate_acquire()) {
817 error = -EBUSY;
818 goto Unlock;
819 }
820
821 pr_info("hibernation entry\n");
822 pm_prepare_console();
823 error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
824 if (error)
825 goto Restore;
826
827 ksys_sync_helper();
828 if (filesystem_freeze_enabled)
829 filesystems_freeze();
830
831 error = freeze_processes();
832 if (error)
833 goto Exit;
834
835 lock_device_hotplug();
836 /* Allocate memory management structures */
837 error = create_basic_memory_bitmaps();
838 if (error)
839 goto Thaw;
840
841 error = hibernation_snapshot(platform_mode: hibernation_mode == HIBERNATION_PLATFORM);
842 if (error || freezer_test_done)
843 goto Free_bitmaps;
844
845 if (in_suspend) {
846 unsigned int flags = 0;
847
848 if (hibernation_mode == HIBERNATION_PLATFORM)
849 flags |= SF_PLATFORM_MODE;
850 if (nocompress) {
851 flags |= SF_NOCOMPRESS_MODE;
852 } else {
853 flags |= SF_CRC32_MODE;
854
855 /*
856 * By default, LZO compression is enabled. Use SF_COMPRESSION_ALG_LZ4
857 * to override this behaviour and use LZ4.
858 *
859 * Refer kernel/power/power.h for more details
860 */
861
862 if (!strcmp(hib_comp_algo, COMPRESSION_ALGO_LZ4))
863 flags |= SF_COMPRESSION_ALG_LZ4;
864 else
865 flags |= SF_COMPRESSION_ALG_LZO;
866 }
867
868 pm_pr_dbg("Writing hibernation image.\n");
869 error = swsusp_write(flags);
870 swsusp_free();
871 if (!error) {
872 if (hibernation_mode == HIBERNATION_TEST_RESUME)
873 snapshot_test = true;
874 else
875 power_down();
876 }
877 in_suspend = 0;
878 pm_restore_gfp_mask();
879 } else {
880 pm_pr_dbg("Hibernation image restored successfully.\n");
881 }
882
883 Free_bitmaps:
884 free_basic_memory_bitmaps();
885 Thaw:
886 unlock_device_hotplug();
887 if (snapshot_test) {
888 pm_pr_dbg("Checking hibernation image\n");
889 error = swsusp_check(exclusive: false);
890 if (!error)
891 error = load_image_and_restore();
892 }
893 thaw_processes();
894
895 /* Don't bother checking whether freezer_test_done is true */
896 freezer_test_done = false;
897 Exit:
898 filesystems_thaw();
899 pm_notifier_call_chain(PM_POST_HIBERNATION);
900 Restore:
901 pm_restore_console();
902 hibernate_release();
903 Unlock:
904 unlock_system_sleep(sleep_flags);
905 pr_info("hibernation exit\n");
906
907 return error;
908}
909
910/**
911 * hibernate_quiet_exec - Execute a function with all devices frozen.
912 * @func: Function to execute.
913 * @data: Data pointer to pass to @func.
914 *
915 * Return the @func return value or an error code if it cannot be executed.
916 */
917int hibernate_quiet_exec(int (*func)(void *data), void *data)
918{
919 unsigned int sleep_flags;
920 int error;
921
922 sleep_flags = lock_system_sleep();
923
924 if (!hibernate_acquire()) {
925 error = -EBUSY;
926 goto unlock;
927 }
928
929 pm_prepare_console();
930
931 error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
932 if (error)
933 goto restore;
934
935 if (filesystem_freeze_enabled)
936 filesystems_freeze();
937
938 error = freeze_processes();
939 if (error)
940 goto exit;
941
942 lock_device_hotplug();
943
944 pm_suspend_clear_flags();
945
946 error = platform_begin(platform_mode: true);
947 if (error)
948 goto thaw;
949
950 error = freeze_kernel_threads();
951 if (error)
952 goto thaw;
953
954 error = dpm_prepare(PMSG_FREEZE);
955 if (error)
956 goto dpm_complete;
957
958 console_suspend_all();
959
960 error = dpm_suspend(PMSG_FREEZE);
961 if (error)
962 goto dpm_resume;
963
964 error = dpm_suspend_end(PMSG_FREEZE);
965 if (error)
966 goto dpm_resume;
967
968 error = platform_pre_snapshot(platform_mode: true);
969 if (error)
970 goto skip;
971
972 error = func(data);
973
974skip:
975 platform_finish(platform_mode: true);
976
977 dpm_resume_start(PMSG_THAW);
978
979dpm_resume:
980 dpm_resume(PMSG_THAW);
981
982 console_resume_all();
983
984dpm_complete:
985 dpm_complete(PMSG_THAW);
986
987 thaw_kernel_threads();
988
989thaw:
990 platform_end(platform_mode: true);
991
992 unlock_device_hotplug();
993
994 thaw_processes();
995
996exit:
997 filesystems_thaw();
998 pm_notifier_call_chain(PM_POST_HIBERNATION);
999
1000restore:
1001 pm_restore_console();
1002
1003 hibernate_release();
1004
1005unlock:
1006 unlock_system_sleep(sleep_flags);
1007
1008 return error;
1009}
1010EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
1011
1012static int __init find_resume_device(void)
1013{
1014 if (!strlen(resume_file))
1015 return -ENOENT;
1016
1017 pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
1018
1019 if (resume_delay) {
1020 pr_info("Waiting %dsec before reading resume device ...\n",
1021 resume_delay);
1022 ssleep(seconds: resume_delay);
1023 }
1024
1025 /* Check if the device is there */
1026 if (!early_lookup_bdev(pathname: resume_file, dev: &swsusp_resume_device))
1027 return 0;
1028
1029 /*
1030 * Some device discovery might still be in progress; we need to wait for
1031 * this to finish.
1032 */
1033 wait_for_device_probe();
1034 if (resume_wait) {
1035 while (early_lookup_bdev(pathname: resume_file, dev: &swsusp_resume_device))
1036 msleep(msecs: 10);
1037 async_synchronize_full();
1038 }
1039
1040 return early_lookup_bdev(pathname: resume_file, dev: &swsusp_resume_device);
1041}
1042
1043static int software_resume(void)
1044{
1045 int error;
1046
1047 pm_pr_dbg("Hibernation image partition %d:%d present\n",
1048 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
1049
1050 pm_pr_dbg("Looking for hibernation image.\n");
1051
1052 mutex_lock(lock: &system_transition_mutex);
1053 error = swsusp_check(exclusive: true);
1054 if (error)
1055 goto Unlock;
1056
1057 /*
1058 * Check if the hibernation image is compressed. If so, query for
1059 * the algorithm support.
1060 */
1061 if (!(swsusp_header_flags & SF_NOCOMPRESS_MODE)) {
1062 if (swsusp_header_flags & SF_COMPRESSION_ALG_LZ4)
1063 strscpy(hib_comp_algo, COMPRESSION_ALGO_LZ4);
1064 else
1065 strscpy(hib_comp_algo, COMPRESSION_ALGO_LZO);
1066 if (!crypto_has_acomp(alg_name: hib_comp_algo, type: 0, CRYPTO_ALG_ASYNC)) {
1067 pr_err("%s compression is not available\n", hib_comp_algo);
1068 error = -EOPNOTSUPP;
1069 goto Unlock;
1070 }
1071 }
1072
1073 /* The snapshot device should not be opened while we're running */
1074 if (!hibernate_acquire()) {
1075 error = -EBUSY;
1076 swsusp_close();
1077 goto Unlock;
1078 }
1079
1080 pr_info("resume from hibernation\n");
1081 pm_prepare_console();
1082 error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
1083 if (error)
1084 goto Restore;
1085
1086 if (filesystem_freeze_enabled)
1087 filesystems_freeze();
1088
1089 pm_pr_dbg("Preparing processes for hibernation restore.\n");
1090 error = freeze_processes();
1091 if (error) {
1092 filesystems_thaw();
1093 goto Close_Finish;
1094 }
1095
1096 error = freeze_kernel_threads();
1097 if (error) {
1098 thaw_processes();
1099 filesystems_thaw();
1100 goto Close_Finish;
1101 }
1102
1103 error = load_image_and_restore();
1104 thaw_processes();
1105 filesystems_thaw();
1106 Finish:
1107 pm_notifier_call_chain(PM_POST_RESTORE);
1108 Restore:
1109 pm_restore_console();
1110 pr_info("resume failed (%d)\n", error);
1111 hibernate_release();
1112 /* For success case, the suspend path will release the lock */
1113 Unlock:
1114 mutex_unlock(lock: &system_transition_mutex);
1115 pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
1116 return error;
1117 Close_Finish:
1118 swsusp_close();
1119 goto Finish;
1120}
1121
1122/**
1123 * software_resume_initcall - Resume from a saved hibernation image.
1124 *
1125 * This routine is called as a late initcall, when all devices have been
1126 * discovered and initialized already.
1127 *
1128 * The image reading code is called to see if there is a hibernation image
1129 * available for reading. If that is the case, devices are quiesced and the
1130 * contents of memory is restored from the saved image.
1131 *
1132 * If this is successful, control reappears in the restored target kernel in
1133 * hibernation_snapshot() which returns to hibernate(). Otherwise, the routine
1134 * attempts to recover gracefully and make the kernel return to the normal mode
1135 * of operation.
1136 */
1137static int __init software_resume_initcall(void)
1138{
1139 /*
1140 * If the user said "noresume".. bail out early.
1141 */
1142 if (noresume || !hibernation_available())
1143 return 0;
1144
1145 if (!swsusp_resume_device) {
1146 int error = find_resume_device();
1147
1148 if (error)
1149 return error;
1150 }
1151
1152 return software_resume();
1153}
1154late_initcall_sync(software_resume_initcall);
1155
1156
1157static const char * const hibernation_modes[] = {
1158 [HIBERNATION_PLATFORM] = "platform",
1159 [HIBERNATION_SHUTDOWN] = "shutdown",
1160 [HIBERNATION_REBOOT] = "reboot",
1161#ifdef CONFIG_SUSPEND
1162 [HIBERNATION_SUSPEND] = "suspend",
1163#endif
1164 [HIBERNATION_TEST_RESUME] = "test_resume",
1165};
1166
1167/*
1168 * /sys/power/disk - Control hibernation mode.
1169 *
1170 * Hibernation can be handled in several ways. There are a few different ways
1171 * to put the system into the sleep state: using the platform driver (e.g. ACPI
1172 * or other hibernation_ops), powering it off or rebooting it (for testing
1173 * mostly).
1174 *
1175 * The sysfs file /sys/power/disk provides an interface for selecting the
1176 * hibernation mode to use. Reading from this file causes the available modes
1177 * to be printed. There are 3 modes that can be supported:
1178 *
1179 * 'platform'
1180 * 'shutdown'
1181 * 'reboot'
1182 *
1183 * If a platform hibernation driver is in use, 'platform' will be supported
1184 * and will be used by default. Otherwise, 'shutdown' will be used by default.
1185 * The selected option (i.e. the one corresponding to the current value of
1186 * hibernation_mode) is enclosed by a square bracket.
1187 *
1188 * To select a given hibernation mode it is necessary to write the mode's
1189 * string representation (as returned by reading from /sys/power/disk) back
1190 * into /sys/power/disk.
1191 */
1192
1193static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1194 char *buf)
1195{
1196 ssize_t count = 0;
1197 int i;
1198
1199 if (!hibernation_available())
1200 return sysfs_emit(buf, fmt: "[disabled]\n");
1201
1202 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1203 if (!hibernation_modes[i])
1204 continue;
1205 switch (i) {
1206 case HIBERNATION_SHUTDOWN:
1207 case HIBERNATION_REBOOT:
1208#ifdef CONFIG_SUSPEND
1209 case HIBERNATION_SUSPEND:
1210#endif
1211 case HIBERNATION_TEST_RESUME:
1212 break;
1213 case HIBERNATION_PLATFORM:
1214 if (hibernation_ops)
1215 break;
1216 /* not a valid mode, continue with loop */
1217 continue;
1218 }
1219 if (i == hibernation_mode)
1220 count += sysfs_emit_at(buf, at: count, fmt: "[%s] ", hibernation_modes[i]);
1221 else
1222 count += sysfs_emit_at(buf, at: count, fmt: "%s ", hibernation_modes[i]);
1223 }
1224
1225 /* Convert the last space to a newline if needed. */
1226 if (count > 0)
1227 buf[count - 1] = '\n';
1228
1229 return count;
1230}
1231
1232static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1233 const char *buf, size_t n)
1234{
1235 int mode = HIBERNATION_INVALID;
1236 unsigned int sleep_flags;
1237 int error = 0;
1238 int len;
1239 char *p;
1240 int i;
1241
1242 if (!hibernation_available())
1243 return -EPERM;
1244
1245 p = memchr(buf, '\n', n);
1246 len = p ? p - buf : n;
1247
1248 sleep_flags = lock_system_sleep();
1249 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1250 if (len == strlen(hibernation_modes[i])
1251 && !strncmp(buf, hibernation_modes[i], len)) {
1252 mode = i;
1253 break;
1254 }
1255 }
1256 if (mode != HIBERNATION_INVALID) {
1257 switch (mode) {
1258 case HIBERNATION_SHUTDOWN:
1259 case HIBERNATION_REBOOT:
1260#ifdef CONFIG_SUSPEND
1261 case HIBERNATION_SUSPEND:
1262#endif
1263 case HIBERNATION_TEST_RESUME:
1264 hibernation_mode = mode;
1265 break;
1266 case HIBERNATION_PLATFORM:
1267 if (hibernation_ops)
1268 hibernation_mode = mode;
1269 else
1270 error = -EINVAL;
1271 }
1272 } else
1273 error = -EINVAL;
1274
1275 if (!error)
1276 pm_pr_dbg("Hibernation mode set to '%s'\n",
1277 hibernation_modes[mode]);
1278 unlock_system_sleep(sleep_flags);
1279 return error ? error : n;
1280}
1281
1282power_attr(disk);
1283
1284static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1285 char *buf)
1286{
1287 return sysfs_emit(buf, fmt: "%d:%d\n", MAJOR(swsusp_resume_device),
1288 MINOR(swsusp_resume_device));
1289}
1290
1291static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1292 const char *buf, size_t n)
1293{
1294 unsigned int sleep_flags;
1295 int len = n;
1296 char *name;
1297 dev_t dev;
1298 int error;
1299
1300 if (!hibernation_available())
1301 return n;
1302
1303 if (len && buf[len-1] == '\n')
1304 len--;
1305 name = kstrndup(s: buf, len, GFP_KERNEL);
1306 if (!name)
1307 return -ENOMEM;
1308
1309 error = lookup_bdev(pathname: name, dev: &dev);
1310 if (error) {
1311 unsigned maj, min, offset;
1312 char *p, dummy;
1313
1314 error = 0;
1315 if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 ||
1316 sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset,
1317 &dummy) == 3) {
1318 dev = MKDEV(maj, min);
1319 if (maj != MAJOR(dev) || min != MINOR(dev))
1320 error = -EINVAL;
1321 } else {
1322 dev = new_decode_dev(dev: simple_strtoul(name, &p, 16));
1323 if (*p)
1324 error = -EINVAL;
1325 }
1326 }
1327 kfree(objp: name);
1328 if (error)
1329 return error;
1330
1331 sleep_flags = lock_system_sleep();
1332 swsusp_resume_device = dev;
1333 unlock_system_sleep(sleep_flags);
1334
1335 pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1336 swsusp_resume_device);
1337 noresume = 0;
1338 software_resume();
1339 return n;
1340}
1341
1342power_attr(resume);
1343
1344static ssize_t resume_offset_show(struct kobject *kobj,
1345 struct kobj_attribute *attr, char *buf)
1346{
1347 return sysfs_emit(buf, fmt: "%llu\n", (unsigned long long)swsusp_resume_block);
1348}
1349
1350static ssize_t resume_offset_store(struct kobject *kobj,
1351 struct kobj_attribute *attr, const char *buf,
1352 size_t n)
1353{
1354 unsigned long long offset;
1355 int rc;
1356
1357 rc = kstrtoull(s: buf, base: 0, res: &offset);
1358 if (rc)
1359 return rc;
1360 swsusp_resume_block = offset;
1361
1362 return n;
1363}
1364
1365power_attr(resume_offset);
1366
1367static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1368 char *buf)
1369{
1370 return sysfs_emit(buf, fmt: "%lu\n", image_size);
1371}
1372
1373static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1374 const char *buf, size_t n)
1375{
1376 unsigned long size;
1377
1378 if (sscanf(buf, "%lu", &size) == 1) {
1379 image_size = size;
1380 return n;
1381 }
1382
1383 return -EINVAL;
1384}
1385
1386power_attr(image_size);
1387
1388static ssize_t reserved_size_show(struct kobject *kobj,
1389 struct kobj_attribute *attr, char *buf)
1390{
1391 return sysfs_emit(buf, fmt: "%lu\n", reserved_size);
1392}
1393
1394static ssize_t reserved_size_store(struct kobject *kobj,
1395 struct kobj_attribute *attr,
1396 const char *buf, size_t n)
1397{
1398 unsigned long size;
1399
1400 if (sscanf(buf, "%lu", &size) == 1) {
1401 reserved_size = size;
1402 return n;
1403 }
1404
1405 return -EINVAL;
1406}
1407
1408power_attr(reserved_size);
1409
1410static struct attribute *g[] = {
1411 &disk_attr.attr,
1412 &resume_offset_attr.attr,
1413 &resume_attr.attr,
1414 &image_size_attr.attr,
1415 &reserved_size_attr.attr,
1416 NULL,
1417};
1418
1419
1420static const struct attribute_group attr_group = {
1421 .attrs = g,
1422};
1423
1424
1425static int __init pm_disk_init(void)
1426{
1427 return sysfs_create_group(kobj: power_kobj, grp: &attr_group);
1428}
1429
1430core_initcall(pm_disk_init);
1431
1432
1433static int __init resume_setup(char *str)
1434{
1435 if (noresume)
1436 return 1;
1437
1438 strscpy(resume_file, str);
1439 return 1;
1440}
1441
1442static int __init resume_offset_setup(char *str)
1443{
1444 unsigned long long offset;
1445
1446 if (noresume)
1447 return 1;
1448
1449 if (sscanf(str, "%llu", &offset) == 1)
1450 swsusp_resume_block = offset;
1451
1452 return 1;
1453}
1454
1455static int __init hibernate_setup(char *str)
1456{
1457 if (!strncmp(str, "noresume", 8)) {
1458 noresume = 1;
1459 } else if (!strncmp(str, "nocompress", 10)) {
1460 nocompress = 1;
1461 } else if (!strncmp(str, "no", 2)) {
1462 noresume = 1;
1463 nohibernate = 1;
1464 } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1465 && !strncmp(str, "protect_image", 13)) {
1466 enable_restore_image_protection();
1467 }
1468 return 1;
1469}
1470
1471static int __init noresume_setup(char *str)
1472{
1473 noresume = 1;
1474 return 1;
1475}
1476
1477static int __init resumewait_setup(char *str)
1478{
1479 resume_wait = 1;
1480 return 1;
1481}
1482
1483static int __init resumedelay_setup(char *str)
1484{
1485 int rc = kstrtouint(s: str, base: 0, res: &resume_delay);
1486
1487 if (rc)
1488 pr_warn("resumedelay: bad option string '%s'\n", str);
1489 return 1;
1490}
1491
1492static int __init nohibernate_setup(char *str)
1493{
1494 noresume = 1;
1495 nohibernate = 1;
1496 return 1;
1497}
1498
1499static const char * const comp_alg_enabled[] = {
1500#if IS_ENABLED(CONFIG_CRYPTO_LZO)
1501 COMPRESSION_ALGO_LZO,
1502#endif
1503#if IS_ENABLED(CONFIG_CRYPTO_LZ4)
1504 COMPRESSION_ALGO_LZ4,
1505#endif
1506};
1507
1508static int hibernate_compressor_param_set(const char *compressor,
1509 const struct kernel_param *kp)
1510{
1511 int index, ret;
1512
1513 if (!mutex_trylock(lock: &system_transition_mutex))
1514 return -EBUSY;
1515
1516 index = sysfs_match_string(comp_alg_enabled, compressor);
1517 if (index >= 0) {
1518 ret = param_set_copystring(val: comp_alg_enabled[index], kp);
1519 if (!ret)
1520 strscpy(hib_comp_algo, comp_alg_enabled[index]);
1521 } else {
1522 ret = index;
1523 }
1524
1525 mutex_unlock(lock: &system_transition_mutex);
1526
1527 if (ret)
1528 pr_debug("Cannot set specified compressor %s\n",
1529 compressor);
1530
1531 return ret;
1532}
1533
1534static const struct kernel_param_ops hibernate_compressor_param_ops = {
1535 .set = hibernate_compressor_param_set,
1536 .get = param_get_string,
1537};
1538
1539static struct kparam_string hibernate_compressor_param_string = {
1540 .maxlen = sizeof(hibernate_compressor),
1541 .string = hibernate_compressor,
1542};
1543
1544module_param_cb(compressor, &hibernate_compressor_param_ops,
1545 &hibernate_compressor_param_string, 0644);
1546MODULE_PARM_DESC(compressor,
1547 "Compression algorithm to be used with hibernation");
1548
1549__setup("noresume", noresume_setup);
1550__setup("resume_offset=", resume_offset_setup);
1551__setup("resume=", resume_setup);
1552__setup("hibernate=", hibernate_setup);
1553__setup("resumewait", resumewait_setup);
1554__setup("resumedelay=", resumedelay_setup);
1555__setup("nohibernate", nohibernate_setup);
1556