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1/*
2 * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
7 * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
8 *
9 * This file is released under the GPLv2.
10 */
11
12#include <linux/suspend.h>
13#include <linux/syscalls.h>
14#include <linux/reboot.h>
15#include <linux/string.h>
16#include <linux/device.h>
17#include <linux/kmod.h>
18#include <linux/delay.h>
19#include <linux/fs.h>
20#include <linux/mount.h>
21#include <linux/pm.h>
22#include <linux/console.h>
23#include <linux/cpu.h>
24#include <linux/freezer.h>
25#include <linux/gfp.h>
26#include <linux/syscore_ops.h>
27#include <scsi/scsi_scan.h>
28
29#include "power.h"
30
31
32static int nocompress = 0;
33static int noresume = 0;
34static char resume_file[256] = CONFIG_PM_STD_PARTITION;
35dev_t swsusp_resume_device;
36sector_t swsusp_resume_block;
37int in_suspend __nosavedata = 0;
38
39enum {
40 HIBERNATION_INVALID,
41 HIBERNATION_PLATFORM,
42 HIBERNATION_TEST,
43 HIBERNATION_TESTPROC,
44 HIBERNATION_SHUTDOWN,
45 HIBERNATION_REBOOT,
46 /* keep last */
47 __HIBERNATION_AFTER_LAST
48};
49#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
50#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
51
52static int hibernation_mode = HIBERNATION_SHUTDOWN;
53
54static const struct platform_hibernation_ops *hibernation_ops;
55
56/**
57 * hibernation_set_ops - Set the global hibernate operations.
58 * @ops: Hibernation operations to use in subsequent hibernation transitions.
59 */
60void hibernation_set_ops(const struct platform_hibernation_ops *ops)
61{
62 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
63 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
64 && ops->restore_cleanup && ops->leave)) {
65 WARN_ON(1);
66 return;
67 }
68 mutex_lock(&pm_mutex);
69 hibernation_ops = ops;
70 if (ops)
71 hibernation_mode = HIBERNATION_PLATFORM;
72 else if (hibernation_mode == HIBERNATION_PLATFORM)
73 hibernation_mode = HIBERNATION_SHUTDOWN;
74
75 mutex_unlock(&pm_mutex);
76}
77
78static bool entering_platform_hibernation;
79
80bool system_entering_hibernation(void)
81{
82 return entering_platform_hibernation;
83}
84EXPORT_SYMBOL(system_entering_hibernation);
85
86#ifdef CONFIG_PM_DEBUG
87static void hibernation_debug_sleep(void)
88{
89 printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
90 mdelay(5000);
91}
92
93static int hibernation_testmode(int mode)
94{
95 if (hibernation_mode == mode) {
96 hibernation_debug_sleep();
97 return 1;
98 }
99 return 0;
100}
101
102static int hibernation_test(int level)
103{
104 if (pm_test_level == level) {
105 hibernation_debug_sleep();
106 return 1;
107 }
108 return 0;
109}
110#else /* !CONFIG_PM_DEBUG */
111static int hibernation_testmode(int mode) { return 0; }
112static int hibernation_test(int level) { return 0; }
113#endif /* !CONFIG_PM_DEBUG */
114
115/**
116 * platform_begin - Call platform to start hibernation.
117 * @platform_mode: Whether or not to use the platform driver.
118 */
119static int platform_begin(int platform_mode)
120{
121 return (platform_mode && hibernation_ops) ?
122 hibernation_ops->begin() : 0;
123}
124
125/**
126 * platform_end - Call platform to finish transition to the working state.
127 * @platform_mode: Whether or not to use the platform driver.
128 */
129static void platform_end(int platform_mode)
130{
131 if (platform_mode && hibernation_ops)
132 hibernation_ops->end();
133}
134
135/**
136 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
137 * @platform_mode: Whether or not to use the platform driver.
138 *
139 * Use the platform driver to prepare the system for creating a hibernate image,
140 * if so configured, and return an error code if that fails.
141 */
142
143static int platform_pre_snapshot(int platform_mode)
144{
145 return (platform_mode && hibernation_ops) ?
146 hibernation_ops->pre_snapshot() : 0;
147}
148
149/**
150 * platform_leave - Call platform to prepare a transition to the working state.
151 * @platform_mode: Whether or not to use the platform driver.
152 *
153 * Use the platform driver prepare to prepare the machine for switching to the
154 * normal mode of operation.
155 *
156 * This routine is called on one CPU with interrupts disabled.
157 */
158static void platform_leave(int platform_mode)
159{
160 if (platform_mode && hibernation_ops)
161 hibernation_ops->leave();
162}
163
164/**
165 * platform_finish - Call platform to switch the system to the working state.
166 * @platform_mode: Whether or not to use the platform driver.
167 *
168 * Use the platform driver to switch the machine to the normal mode of
169 * operation.
170 *
171 * This routine must be called after platform_prepare().
172 */
173static void platform_finish(int platform_mode)
174{
175 if (platform_mode && hibernation_ops)
176 hibernation_ops->finish();
177}
178
179/**
180 * platform_pre_restore - Prepare for hibernate image restoration.
181 * @platform_mode: Whether or not to use the platform driver.
182 *
183 * Use the platform driver to prepare the system for resume from a hibernation
184 * image.
185 *
186 * If the restore fails after this function has been called,
187 * platform_restore_cleanup() must be called.
188 */
189static int platform_pre_restore(int platform_mode)
190{
191 return (platform_mode && hibernation_ops) ?
192 hibernation_ops->pre_restore() : 0;
193}
194
195/**
196 * platform_restore_cleanup - Switch to the working state after failing restore.
197 * @platform_mode: Whether or not to use the platform driver.
198 *
199 * Use the platform driver to switch the system to the normal mode of operation
200 * after a failing restore.
201 *
202 * If platform_pre_restore() has been called before the failing restore, this
203 * function must be called too, regardless of the result of
204 * platform_pre_restore().
205 */
206static void platform_restore_cleanup(int platform_mode)
207{
208 if (platform_mode && hibernation_ops)
209 hibernation_ops->restore_cleanup();
210}
211
212/**
213 * platform_recover - Recover from a failure to suspend devices.
214 * @platform_mode: Whether or not to use the platform driver.
215 */
216static void platform_recover(int platform_mode)
217{
218 if (platform_mode && hibernation_ops && hibernation_ops->recover)
219 hibernation_ops->recover();
220}
221
222/**
223 * swsusp_show_speed - Print time elapsed between two events during hibernation.
224 * @start: Starting event.
225 * @stop: Final event.
226 * @nr_pages: Number of memory pages processed between @start and @stop.
227 * @msg: Additional diagnostic message to print.
228 */
229void swsusp_show_speed(struct timeval *start, struct timeval *stop,
230 unsigned nr_pages, char *msg)
231{
232 s64 elapsed_centisecs64;
233 int centisecs;
234 int k;
235 int kps;
236
237 elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
238 do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
239 centisecs = elapsed_centisecs64;
240 if (centisecs == 0)
241 centisecs = 1; /* avoid div-by-zero */
242 k = nr_pages * (PAGE_SIZE / 1024);
243 kps = (k * 100) / centisecs;
244 printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
245 msg, k,
246 centisecs / 100, centisecs % 100,
247 kps / 1000, (kps % 1000) / 10);
248}
249
250/**
251 * create_image - Create a hibernation image.
252 * @platform_mode: Whether or not to use the platform driver.
253 *
254 * Execute device drivers' .freeze_noirq() callbacks, create a hibernation image
255 * and execute the drivers' .thaw_noirq() callbacks.
256 *
257 * Control reappears in this routine after the subsequent restore.
258 */
259static int create_image(int platform_mode)
260{
261 int error;
262
263 error = dpm_suspend_noirq(PMSG_FREEZE);
264 if (error) {
265 printk(KERN_ERR "PM: Some devices failed to power down, "
266 "aborting hibernation\n");
267 return error;
268 }
269
270 error = platform_pre_snapshot(platform_mode);
271 if (error || hibernation_test(TEST_PLATFORM))
272 goto Platform_finish;
273
274 error = disable_nonboot_cpus();
275 if (error || hibernation_test(TEST_CPUS)
276 || hibernation_testmode(HIBERNATION_TEST))
277 goto Enable_cpus;
278
279 local_irq_disable();
280
281 error = syscore_suspend();
282 if (error) {
283 printk(KERN_ERR "PM: Some system devices failed to power down, "
284 "aborting hibernation\n");
285 goto Enable_irqs;
286 }
287
288 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
289 goto Power_up;
290
291 in_suspend = 1;
292 save_processor_state();
293 error = swsusp_arch_suspend();
294 if (error)
295 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
296 error);
297 /* Restore control flow magically appears here */
298 restore_processor_state();
299 if (!in_suspend) {
300 events_check_enabled = false;
301 platform_leave(platform_mode);
302 }
303
304 Power_up:
305 syscore_resume();
306
307 Enable_irqs:
308 local_irq_enable();
309
310 Enable_cpus:
311 enable_nonboot_cpus();
312
313 Platform_finish:
314 platform_finish(platform_mode);
315
316 dpm_resume_noirq(in_suspend ?
317 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
318
319 return error;
320}
321
322/**
323 * hibernation_snapshot - Quiesce devices and create a hibernation image.
324 * @platform_mode: If set, use platform driver to prepare for the transition.
325 *
326 * This routine must be called with pm_mutex held.
327 */
328int hibernation_snapshot(int platform_mode)
329{
330 pm_message_t msg = PMSG_RECOVER;
331 int error;
332
333 error = platform_begin(platform_mode);
334 if (error)
335 goto Close;
336
337 error = dpm_prepare(PMSG_FREEZE);
338 if (error)
339 goto Complete_devices;
340
341 /* Preallocate image memory before shutting down devices. */
342 error = hibernate_preallocate_memory();
343 if (error)
344 goto Complete_devices;
345
346 suspend_console();
347 pm_restrict_gfp_mask();
348 error = dpm_suspend(PMSG_FREEZE);
349 if (error)
350 goto Recover_platform;
351
352 if (hibernation_test(TEST_DEVICES))
353 goto Recover_platform;
354
355 error = create_image(platform_mode);
356 /*
357 * Control returns here (1) after the image has been created or the
358 * image creation has failed and (2) after a successful restore.
359 */
360
361 Resume_devices:
362 /* We may need to release the preallocated image pages here. */
363 if (error || !in_suspend)
364 swsusp_free();
365
366 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
367 dpm_resume(msg);
368
369 if (error || !in_suspend)
370 pm_restore_gfp_mask();
371
372 resume_console();
373
374 Complete_devices:
375 dpm_complete(msg);
376
377 Close:
378 platform_end(platform_mode);
379 return error;
380
381 Recover_platform:
382 platform_recover(platform_mode);
383 goto Resume_devices;
384}
385
386/**
387 * resume_target_kernel - Restore system state from a hibernation image.
388 * @platform_mode: Whether or not to use the platform driver.
389 *
390 * Execute device drivers' .freeze_noirq() callbacks, restore the contents of
391 * highmem that have not been restored yet from the image and run the low-level
392 * code that will restore the remaining contents of memory and switch to the
393 * just restored target kernel.
394 */
395static int resume_target_kernel(bool platform_mode)
396{
397 int error;
398
399 error = dpm_suspend_noirq(PMSG_QUIESCE);
400 if (error) {
401 printk(KERN_ERR "PM: Some devices failed to power down, "
402 "aborting resume\n");
403 return error;
404 }
405
406 error = platform_pre_restore(platform_mode);
407 if (error)
408 goto Cleanup;
409
410 error = disable_nonboot_cpus();
411 if (error)
412 goto Enable_cpus;
413
414 local_irq_disable();
415
416 error = syscore_suspend();
417 if (error)
418 goto Enable_irqs;
419
420 save_processor_state();
421 error = restore_highmem();
422 if (!error) {
423 error = swsusp_arch_resume();
424 /*
425 * The code below is only ever reached in case of a failure.
426 * Otherwise, execution continues at the place where
427 * swsusp_arch_suspend() was called.
428 */
429 BUG_ON(!error);
430 /*
431 * This call to restore_highmem() reverts the changes made by
432 * the previous one.
433 */
434 restore_highmem();
435 }
436 /*
437 * The only reason why swsusp_arch_resume() can fail is memory being
438 * very tight, so we have to free it as soon as we can to avoid
439 * subsequent failures.
440 */
441 swsusp_free();
442 restore_processor_state();
443 touch_softlockup_watchdog();
444
445 syscore_resume();
446
447 Enable_irqs:
448 local_irq_enable();
449
450 Enable_cpus:
451 enable_nonboot_cpus();
452
453 Cleanup:
454 platform_restore_cleanup(platform_mode);
455
456 dpm_resume_noirq(PMSG_RECOVER);
457
458 return error;
459}
460
461/**
462 * hibernation_restore - Quiesce devices and restore from a hibernation image.
463 * @platform_mode: If set, use platform driver to prepare for the transition.
464 *
465 * This routine must be called with pm_mutex held. If it is successful, control
466 * reappears in the restored target kernel in hibernation_snaphot().
467 */
468int hibernation_restore(int platform_mode)
469{
470 int error;
471
472 pm_prepare_console();
473 suspend_console();
474 pm_restrict_gfp_mask();
475 error = dpm_suspend_start(PMSG_QUIESCE);
476 if (!error) {
477 error = resume_target_kernel(platform_mode);
478 dpm_resume_end(PMSG_RECOVER);
479 }
480 pm_restore_gfp_mask();
481 resume_console();
482 pm_restore_console();
483 return error;
484}
485
486/**
487 * hibernation_platform_enter - Power off the system using the platform driver.
488 */
489int hibernation_platform_enter(void)
490{
491 int error;
492
493 if (!hibernation_ops)
494 return -ENOSYS;
495
496 /*
497 * We have cancelled the power transition by running
498 * hibernation_ops->finish() before saving the image, so we should let
499 * the firmware know that we're going to enter the sleep state after all
500 */
501 error = hibernation_ops->begin();
502 if (error)
503 goto Close;
504
505 entering_platform_hibernation = true;
506 suspend_console();
507 error = dpm_suspend_start(PMSG_HIBERNATE);
508 if (error) {
509 if (hibernation_ops->recover)
510 hibernation_ops->recover();
511 goto Resume_devices;
512 }
513
514 error = dpm_suspend_noirq(PMSG_HIBERNATE);
515 if (error)
516 goto Resume_devices;
517
518 error = hibernation_ops->prepare();
519 if (error)
520 goto Platform_finish;
521
522 error = disable_nonboot_cpus();
523 if (error)
524 goto Platform_finish;
525
526 local_irq_disable();
527 syscore_suspend();
528 if (pm_wakeup_pending()) {
529 error = -EAGAIN;
530 goto Power_up;
531 }
532
533 hibernation_ops->enter();
534 /* We should never get here */
535 while (1);
536
537 Power_up:
538 syscore_resume();
539 local_irq_enable();
540 enable_nonboot_cpus();
541
542 Platform_finish:
543 hibernation_ops->finish();
544
545 dpm_resume_noirq(PMSG_RESTORE);
546
547 Resume_devices:
548 entering_platform_hibernation = false;
549 dpm_resume_end(PMSG_RESTORE);
550 resume_console();
551
552 Close:
553 hibernation_ops->end();
554
555 return error;
556}
557
558/**
559 * power_down - Shut the machine down for hibernation.
560 *
561 * Use the platform driver, if configured, to put the system into the sleep
562 * state corresponding to hibernation, or try to power it off or reboot,
563 * depending on the value of hibernation_mode.
564 */
565static void power_down(void)
566{
567 switch (hibernation_mode) {
568 case HIBERNATION_TEST:
569 case HIBERNATION_TESTPROC:
570 break;
571 case HIBERNATION_REBOOT:
572 kernel_restart(NULL);
573 break;
574 case HIBERNATION_PLATFORM:
575 hibernation_platform_enter();
576 case HIBERNATION_SHUTDOWN:
577 kernel_power_off();
578 break;
579 }
580 kernel_halt();
581 /*
582 * Valid image is on the disk, if we continue we risk serious data
583 * corruption after resume.
584 */
585 printk(KERN_CRIT "PM: Please power down manually\n");
586 while(1);
587}
588
589static int prepare_processes(void)
590{
591 int error = 0;
592
593 if (freeze_processes()) {
594 error = -EBUSY;
595 thaw_processes();
596 }
597 return error;
598}
599
600/**
601 * hibernate - Carry out system hibernation, including saving the image.
602 */
603int hibernate(void)
604{
605 int error;
606
607 mutex_lock(&pm_mutex);
608 /* The snapshot device should not be opened while we're running */
609 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
610 error = -EBUSY;
611 goto Unlock;
612 }
613
614 pm_prepare_console();
615 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
616 if (error)
617 goto Exit;
618
619 error = usermodehelper_disable();
620 if (error)
621 goto Exit;
622
623 /* Allocate memory management structures */
624 error = create_basic_memory_bitmaps();
625 if (error)
626 goto Exit;
627
628 printk(KERN_INFO "PM: Syncing filesystems ... ");
629 sys_sync();
630 printk("done.\n");
631
632 error = prepare_processes();
633 if (error)
634 goto Finish;
635
636 if (hibernation_test(TEST_FREEZER))
637 goto Thaw;
638
639 if (hibernation_testmode(HIBERNATION_TESTPROC))
640 goto Thaw;
641
642 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
643 if (error)
644 goto Thaw;
645
646 if (in_suspend) {
647 unsigned int flags = 0;
648
649 if (hibernation_mode == HIBERNATION_PLATFORM)
650 flags |= SF_PLATFORM_MODE;
651 if (nocompress)
652 flags |= SF_NOCOMPRESS_MODE;
653 pr_debug("PM: writing image.\n");
654 error = swsusp_write(flags);
655 swsusp_free();
656 if (!error)
657 power_down();
658 in_suspend = 0;
659 pm_restore_gfp_mask();
660 } else {
661 pr_debug("PM: Image restored successfully.\n");
662 }
663
664 Thaw:
665 thaw_processes();
666 Finish:
667 free_basic_memory_bitmaps();
668 usermodehelper_enable();
669 Exit:
670 pm_notifier_call_chain(PM_POST_HIBERNATION);
671 pm_restore_console();
672 atomic_inc(&snapshot_device_available);
673 Unlock:
674 mutex_unlock(&pm_mutex);
675 return error;
676}
677
678
679/**
680 * software_resume - Resume from a saved hibernation image.
681 *
682 * This routine is called as a late initcall, when all devices have been
683 * discovered and initialized already.
684 *
685 * The image reading code is called to see if there is a hibernation image
686 * available for reading. If that is the case, devices are quiesced and the
687 * contents of memory is restored from the saved image.
688 *
689 * If this is successful, control reappears in the restored target kernel in
690 * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine
691 * attempts to recover gracefully and make the kernel return to the normal mode
692 * of operation.
693 */
694static int software_resume(void)
695{
696 int error;
697 unsigned int flags;
698
699 /*
700 * If the user said "noresume".. bail out early.
701 */
702 if (noresume)
703 return 0;
704
705 /*
706 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
707 * is configured into the kernel. Since the regular hibernate
708 * trigger path is via sysfs which takes a buffer mutex before
709 * calling hibernate functions (which take pm_mutex) this can
710 * cause lockdep to complain about a possible ABBA deadlock
711 * which cannot happen since we're in the boot code here and
712 * sysfs can't be invoked yet. Therefore, we use a subclass
713 * here to avoid lockdep complaining.
714 */
715 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
716
717 if (swsusp_resume_device)
718 goto Check_image;
719
720 if (!strlen(resume_file)) {
721 error = -ENOENT;
722 goto Unlock;
723 }
724
725 pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
726
727 /* Check if the device is there */
728 swsusp_resume_device = name_to_dev_t(resume_file);
729 if (!swsusp_resume_device) {
730 /*
731 * Some device discovery might still be in progress; we need
732 * to wait for this to finish.
733 */
734 wait_for_device_probe();
735 /*
736 * We can't depend on SCSI devices being available after loading
737 * one of their modules until scsi_complete_async_scans() is
738 * called and the resume device usually is a SCSI one.
739 */
740 scsi_complete_async_scans();
741
742 swsusp_resume_device = name_to_dev_t(resume_file);
743 if (!swsusp_resume_device) {
744 error = -ENODEV;
745 goto Unlock;
746 }
747 }
748
749 Check_image:
750 pr_debug("PM: Hibernation image partition %d:%d present\n",
751 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
752
753 pr_debug("PM: Looking for hibernation image.\n");
754 error = swsusp_check();
755 if (error)
756 goto Unlock;
757
758 /* The snapshot device should not be opened while we're running */
759 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
760 error = -EBUSY;
761 swsusp_close(FMODE_READ);
762 goto Unlock;
763 }
764
765 pm_prepare_console();
766 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
767 if (error)
768 goto close_finish;
769
770 error = usermodehelper_disable();
771 if (error)
772 goto close_finish;
773
774 error = create_basic_memory_bitmaps();
775 if (error)
776 goto close_finish;
777
778 pr_debug("PM: Preparing processes for restore.\n");
779 error = prepare_processes();
780 if (error) {
781 swsusp_close(FMODE_READ);
782 goto Done;
783 }
784
785 pr_debug("PM: Loading hibernation image.\n");
786
787 error = swsusp_read(&flags);
788 swsusp_close(FMODE_READ);
789 if (!error)
790 hibernation_restore(flags & SF_PLATFORM_MODE);
791
792 printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
793 swsusp_free();
794 thaw_processes();
795 Done:
796 free_basic_memory_bitmaps();
797 usermodehelper_enable();
798 Finish:
799 pm_notifier_call_chain(PM_POST_RESTORE);
800 pm_restore_console();
801 atomic_inc(&snapshot_device_available);
802 /* For success case, the suspend path will release the lock */
803 Unlock:
804 mutex_unlock(&pm_mutex);
805 pr_debug("PM: Hibernation image not present or could not be loaded.\n");
806 return error;
807close_finish:
808 swsusp_close(FMODE_READ);
809 goto Finish;
810}
811
812late_initcall(software_resume);
813
814
815static const char * const hibernation_modes[] = {
816 [HIBERNATION_PLATFORM] = "platform",
817 [HIBERNATION_SHUTDOWN] = "shutdown",
818 [HIBERNATION_REBOOT] = "reboot",
819 [HIBERNATION_TEST] = "test",
820 [HIBERNATION_TESTPROC] = "testproc",
821};
822
823/*
824 * /sys/power/disk - Control hibernation mode.
825 *
826 * Hibernation can be handled in several ways. There are a few different ways
827 * to put the system into the sleep state: using the platform driver (e.g. ACPI
828 * or other hibernation_ops), powering it off or rebooting it (for testing
829 * mostly), or using one of the two available test modes.
830 *
831 * The sysfs file /sys/power/disk provides an interface for selecting the
832 * hibernation mode to use. Reading from this file causes the available modes
833 * to be printed. There are 5 modes that can be supported:
834 *
835 * 'platform'
836 * 'shutdown'
837 * 'reboot'
838 * 'test'
839 * 'testproc'
840 *
841 * If a platform hibernation driver is in use, 'platform' will be supported
842 * and will be used by default. Otherwise, 'shutdown' will be used by default.
843 * The selected option (i.e. the one corresponding to the current value of
844 * hibernation_mode) is enclosed by a square bracket.
845 *
846 * To select a given hibernation mode it is necessary to write the mode's
847 * string representation (as returned by reading from /sys/power/disk) back
848 * into /sys/power/disk.
849 */
850
851static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
852 char *buf)
853{
854 int i;
855 char *start = buf;
856
857 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
858 if (!hibernation_modes[i])
859 continue;
860 switch (i) {
861 case HIBERNATION_SHUTDOWN:
862 case HIBERNATION_REBOOT:
863 case HIBERNATION_TEST:
864 case HIBERNATION_TESTPROC:
865 break;
866 case HIBERNATION_PLATFORM:
867 if (hibernation_ops)
868 break;
869 /* not a valid mode, continue with loop */
870 continue;
871 }
872 if (i == hibernation_mode)
873 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
874 else
875 buf += sprintf(buf, "%s ", hibernation_modes[i]);
876 }
877 buf += sprintf(buf, "\n");
878 return buf-start;
879}
880
881static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
882 const char *buf, size_t n)
883{
884 int error = 0;
885 int i;
886 int len;
887 char *p;
888 int mode = HIBERNATION_INVALID;
889
890 p = memchr(buf, '\n', n);
891 len = p ? p - buf : n;
892
893 mutex_lock(&pm_mutex);
894 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
895 if (len == strlen(hibernation_modes[i])
896 && !strncmp(buf, hibernation_modes[i], len)) {
897 mode = i;
898 break;
899 }
900 }
901 if (mode != HIBERNATION_INVALID) {
902 switch (mode) {
903 case HIBERNATION_SHUTDOWN:
904 case HIBERNATION_REBOOT:
905 case HIBERNATION_TEST:
906 case HIBERNATION_TESTPROC:
907 hibernation_mode = mode;
908 break;
909 case HIBERNATION_PLATFORM:
910 if (hibernation_ops)
911 hibernation_mode = mode;
912 else
913 error = -EINVAL;
914 }
915 } else
916 error = -EINVAL;
917
918 if (!error)
919 pr_debug("PM: Hibernation mode set to '%s'\n",
920 hibernation_modes[mode]);
921 mutex_unlock(&pm_mutex);
922 return error ? error : n;
923}
924
925power_attr(disk);
926
927static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
928 char *buf)
929{
930 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
931 MINOR(swsusp_resume_device));
932}
933
934static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
935 const char *buf, size_t n)
936{
937 unsigned int maj, min;
938 dev_t res;
939 int ret = -EINVAL;
940
941 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
942 goto out;
943
944 res = MKDEV(maj,min);
945 if (maj != MAJOR(res) || min != MINOR(res))
946 goto out;
947
948 mutex_lock(&pm_mutex);
949 swsusp_resume_device = res;
950 mutex_unlock(&pm_mutex);
951 printk(KERN_INFO "PM: Starting manual resume from disk\n");
952 noresume = 0;
953 software_resume();
954 ret = n;
955 out:
956 return ret;
957}
958
959power_attr(resume);
960
961static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
962 char *buf)
963{
964 return sprintf(buf, "%lu\n", image_size);
965}
966
967static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
968 const char *buf, size_t n)
969{
970 unsigned long size;
971
972 if (sscanf(buf, "%lu", &size) == 1) {
973 image_size = size;
974 return n;
975 }
976
977 return -EINVAL;
978}
979
980power_attr(image_size);
981
982static ssize_t reserved_size_show(struct kobject *kobj,
983 struct kobj_attribute *attr, char *buf)
984{
985 return sprintf(buf, "%lu\n", reserved_size);
986}
987
988static ssize_t reserved_size_store(struct kobject *kobj,
989 struct kobj_attribute *attr,
990 const char *buf, size_t n)
991{
992 unsigned long size;
993
994 if (sscanf(buf, "%lu", &size) == 1) {
995 reserved_size = size;
996 return n;
997 }
998
999 return -EINVAL;
1000}
1001
1002power_attr(reserved_size);
1003
1004static struct attribute * g[] = {
1005 &disk_attr.attr,
1006 &resume_attr.attr,
1007 &image_size_attr.attr,
1008 &reserved_size_attr.attr,
1009 NULL,
1010};
1011
1012
1013static struct attribute_group attr_group = {
1014 .attrs = g,
1015};
1016
1017
1018static int __init pm_disk_init(void)
1019{
1020 return sysfs_create_group(power_kobj, &attr_group);
1021}
1022
1023core_initcall(pm_disk_init);
1024
1025
1026static int __init resume_setup(char *str)
1027{
1028 if (noresume)
1029 return 1;
1030
1031 strncpy( resume_file, str, 255 );
1032 return 1;
1033}
1034
1035static int __init resume_offset_setup(char *str)
1036{
1037 unsigned long long offset;
1038
1039 if (noresume)
1040 return 1;
1041
1042 if (sscanf(str, "%llu", &offset) == 1)
1043 swsusp_resume_block = offset;
1044
1045 return 1;
1046}
1047
1048static int __init hibernate_setup(char *str)
1049{
1050 if (!strncmp(str, "noresume", 8))
1051 noresume = 1;
1052 else if (!strncmp(str, "nocompress", 10))
1053 nocompress = 1;
1054 return 1;
1055}
1056
1057static int __init noresume_setup(char *str)
1058{
1059 noresume = 1;
1060 return 1;
1061}
1062
1063__setup("noresume", noresume_setup);
1064__setup("resume_offset=", resume_offset_setup);
1065__setup("resume=", resume_setup);
1066__setup("hibernate=", hibernate_setup);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
4 *
5 * Copyright (c) 2003 Patrick Mochel
6 * Copyright (c) 2003 Open Source Development Lab
7 * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
8 * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
9 * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
10 */
11
12#define pr_fmt(fmt) "PM: hibernation: " fmt
13
14#include <linux/blkdev.h>
15#include <linux/export.h>
16#include <linux/suspend.h>
17#include <linux/reboot.h>
18#include <linux/string.h>
19#include <linux/device.h>
20#include <linux/async.h>
21#include <linux/delay.h>
22#include <linux/fs.h>
23#include <linux/mount.h>
24#include <linux/pm.h>
25#include <linux/nmi.h>
26#include <linux/console.h>
27#include <linux/cpu.h>
28#include <linux/freezer.h>
29#include <linux/gfp.h>
30#include <linux/syscore_ops.h>
31#include <linux/ctype.h>
32#include <linux/ktime.h>
33#include <linux/security.h>
34#include <linux/secretmem.h>
35#include <trace/events/power.h>
36
37#include "power.h"
38
39
40static int nocompress;
41static int noresume;
42static int nohibernate;
43static int resume_wait;
44static unsigned int resume_delay;
45static char resume_file[256] = CONFIG_PM_STD_PARTITION;
46dev_t swsusp_resume_device;
47sector_t swsusp_resume_block;
48__visible int in_suspend __nosavedata;
49
50enum {
51 HIBERNATION_INVALID,
52 HIBERNATION_PLATFORM,
53 HIBERNATION_SHUTDOWN,
54 HIBERNATION_REBOOT,
55#ifdef CONFIG_SUSPEND
56 HIBERNATION_SUSPEND,
57#endif
58 HIBERNATION_TEST_RESUME,
59 /* keep last */
60 __HIBERNATION_AFTER_LAST
61};
62#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
63#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
64
65static int hibernation_mode = HIBERNATION_SHUTDOWN;
66
67bool freezer_test_done;
68
69static const struct platform_hibernation_ops *hibernation_ops;
70
71static atomic_t hibernate_atomic = ATOMIC_INIT(1);
72
73bool hibernate_acquire(void)
74{
75 return atomic_add_unless(&hibernate_atomic, -1, 0);
76}
77
78void hibernate_release(void)
79{
80 atomic_inc(&hibernate_atomic);
81}
82
83bool hibernation_available(void)
84{
85 return nohibernate == 0 &&
86 !security_locked_down(LOCKDOWN_HIBERNATION) &&
87 !secretmem_active() && !cxl_mem_active();
88}
89
90/**
91 * hibernation_set_ops - Set the global hibernate operations.
92 * @ops: Hibernation operations to use in subsequent hibernation transitions.
93 */
94void hibernation_set_ops(const struct platform_hibernation_ops *ops)
95{
96 unsigned int sleep_flags;
97
98 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
99 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
100 && ops->restore_cleanup && ops->leave)) {
101 WARN_ON(1);
102 return;
103 }
104
105 sleep_flags = lock_system_sleep();
106
107 hibernation_ops = ops;
108 if (ops)
109 hibernation_mode = HIBERNATION_PLATFORM;
110 else if (hibernation_mode == HIBERNATION_PLATFORM)
111 hibernation_mode = HIBERNATION_SHUTDOWN;
112
113 unlock_system_sleep(sleep_flags);
114}
115EXPORT_SYMBOL_GPL(hibernation_set_ops);
116
117static bool entering_platform_hibernation;
118
119bool system_entering_hibernation(void)
120{
121 return entering_platform_hibernation;
122}
123EXPORT_SYMBOL(system_entering_hibernation);
124
125#ifdef CONFIG_PM_DEBUG
126static void hibernation_debug_sleep(void)
127{
128 pr_info("debug: Waiting for 5 seconds.\n");
129 mdelay(5000);
130}
131
132static int hibernation_test(int level)
133{
134 if (pm_test_level == level) {
135 hibernation_debug_sleep();
136 return 1;
137 }
138 return 0;
139}
140#else /* !CONFIG_PM_DEBUG */
141static int hibernation_test(int level) { return 0; }
142#endif /* !CONFIG_PM_DEBUG */
143
144/**
145 * platform_begin - Call platform to start hibernation.
146 * @platform_mode: Whether or not to use the platform driver.
147 */
148static int platform_begin(int platform_mode)
149{
150 return (platform_mode && hibernation_ops) ?
151 hibernation_ops->begin(PMSG_FREEZE) : 0;
152}
153
154/**
155 * platform_end - Call platform to finish transition to the working state.
156 * @platform_mode: Whether or not to use the platform driver.
157 */
158static void platform_end(int platform_mode)
159{
160 if (platform_mode && hibernation_ops)
161 hibernation_ops->end();
162}
163
164/**
165 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
166 * @platform_mode: Whether or not to use the platform driver.
167 *
168 * Use the platform driver to prepare the system for creating a hibernate image,
169 * if so configured, and return an error code if that fails.
170 */
171
172static int platform_pre_snapshot(int platform_mode)
173{
174 return (platform_mode && hibernation_ops) ?
175 hibernation_ops->pre_snapshot() : 0;
176}
177
178/**
179 * platform_leave - Call platform to prepare a transition to the working state.
180 * @platform_mode: Whether or not to use the platform driver.
181 *
182 * Use the platform driver prepare to prepare the machine for switching to the
183 * normal mode of operation.
184 *
185 * This routine is called on one CPU with interrupts disabled.
186 */
187static void platform_leave(int platform_mode)
188{
189 if (platform_mode && hibernation_ops)
190 hibernation_ops->leave();
191}
192
193/**
194 * platform_finish - Call platform to switch the system to the working state.
195 * @platform_mode: Whether or not to use the platform driver.
196 *
197 * Use the platform driver to switch the machine to the normal mode of
198 * operation.
199 *
200 * This routine must be called after platform_prepare().
201 */
202static void platform_finish(int platform_mode)
203{
204 if (platform_mode && hibernation_ops)
205 hibernation_ops->finish();
206}
207
208/**
209 * platform_pre_restore - Prepare for hibernate image restoration.
210 * @platform_mode: Whether or not to use the platform driver.
211 *
212 * Use the platform driver to prepare the system for resume from a hibernation
213 * image.
214 *
215 * If the restore fails after this function has been called,
216 * platform_restore_cleanup() must be called.
217 */
218static int platform_pre_restore(int platform_mode)
219{
220 return (platform_mode && hibernation_ops) ?
221 hibernation_ops->pre_restore() : 0;
222}
223
224/**
225 * platform_restore_cleanup - Switch to the working state after failing restore.
226 * @platform_mode: Whether or not to use the platform driver.
227 *
228 * Use the platform driver to switch the system to the normal mode of operation
229 * after a failing restore.
230 *
231 * If platform_pre_restore() has been called before the failing restore, this
232 * function must be called too, regardless of the result of
233 * platform_pre_restore().
234 */
235static void platform_restore_cleanup(int platform_mode)
236{
237 if (platform_mode && hibernation_ops)
238 hibernation_ops->restore_cleanup();
239}
240
241/**
242 * platform_recover - Recover from a failure to suspend devices.
243 * @platform_mode: Whether or not to use the platform driver.
244 */
245static void platform_recover(int platform_mode)
246{
247 if (platform_mode && hibernation_ops && hibernation_ops->recover)
248 hibernation_ops->recover();
249}
250
251/**
252 * swsusp_show_speed - Print time elapsed between two events during hibernation.
253 * @start: Starting event.
254 * @stop: Final event.
255 * @nr_pages: Number of memory pages processed between @start and @stop.
256 * @msg: Additional diagnostic message to print.
257 */
258void swsusp_show_speed(ktime_t start, ktime_t stop,
259 unsigned nr_pages, char *msg)
260{
261 ktime_t diff;
262 u64 elapsed_centisecs64;
263 unsigned int centisecs;
264 unsigned int k;
265 unsigned int kps;
266
267 diff = ktime_sub(stop, start);
268 elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
269 centisecs = elapsed_centisecs64;
270 if (centisecs == 0)
271 centisecs = 1; /* avoid div-by-zero */
272 k = nr_pages * (PAGE_SIZE / 1024);
273 kps = (k * 100) / centisecs;
274 pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
275 msg, k, centisecs / 100, centisecs % 100, kps / 1000,
276 (kps % 1000) / 10);
277}
278
279__weak int arch_resume_nosmt(void)
280{
281 return 0;
282}
283
284/**
285 * create_image - Create a hibernation image.
286 * @platform_mode: Whether or not to use the platform driver.
287 *
288 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
289 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
290 *
291 * Control reappears in this routine after the subsequent restore.
292 */
293static int create_image(int platform_mode)
294{
295 int error;
296
297 error = dpm_suspend_end(PMSG_FREEZE);
298 if (error) {
299 pr_err("Some devices failed to power down, aborting\n");
300 return error;
301 }
302
303 error = platform_pre_snapshot(platform_mode);
304 if (error || hibernation_test(TEST_PLATFORM))
305 goto Platform_finish;
306
307 error = pm_sleep_disable_secondary_cpus();
308 if (error || hibernation_test(TEST_CPUS))
309 goto Enable_cpus;
310
311 local_irq_disable();
312
313 system_state = SYSTEM_SUSPEND;
314
315 error = syscore_suspend();
316 if (error) {
317 pr_err("Some system devices failed to power down, aborting\n");
318 goto Enable_irqs;
319 }
320
321 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
322 goto Power_up;
323
324 in_suspend = 1;
325 save_processor_state();
326 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
327 error = swsusp_arch_suspend();
328 /* Restore control flow magically appears here */
329 restore_processor_state();
330 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
331 if (error)
332 pr_err("Error %d creating image\n", error);
333
334 if (!in_suspend) {
335 events_check_enabled = false;
336 clear_or_poison_free_pages();
337 }
338
339 platform_leave(platform_mode);
340
341 Power_up:
342 syscore_resume();
343
344 Enable_irqs:
345 system_state = SYSTEM_RUNNING;
346 local_irq_enable();
347
348 Enable_cpus:
349 pm_sleep_enable_secondary_cpus();
350
351 /* Allow architectures to do nosmt-specific post-resume dances */
352 if (!in_suspend)
353 error = arch_resume_nosmt();
354
355 Platform_finish:
356 platform_finish(platform_mode);
357
358 dpm_resume_start(in_suspend ?
359 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
360
361 return error;
362}
363
364/**
365 * hibernation_snapshot - Quiesce devices and create a hibernation image.
366 * @platform_mode: If set, use platform driver to prepare for the transition.
367 *
368 * This routine must be called with system_transition_mutex held.
369 */
370int hibernation_snapshot(int platform_mode)
371{
372 pm_message_t msg;
373 int error;
374
375 pm_suspend_clear_flags();
376 error = platform_begin(platform_mode);
377 if (error)
378 goto Close;
379
380 /* Preallocate image memory before shutting down devices. */
381 error = hibernate_preallocate_memory();
382 if (error)
383 goto Close;
384
385 error = freeze_kernel_threads();
386 if (error)
387 goto Cleanup;
388
389 if (hibernation_test(TEST_FREEZER)) {
390
391 /*
392 * Indicate to the caller that we are returning due to a
393 * successful freezer test.
394 */
395 freezer_test_done = true;
396 goto Thaw;
397 }
398
399 error = dpm_prepare(PMSG_FREEZE);
400 if (error) {
401 dpm_complete(PMSG_RECOVER);
402 goto Thaw;
403 }
404
405 suspend_console();
406 pm_restrict_gfp_mask();
407
408 error = dpm_suspend(PMSG_FREEZE);
409
410 if (error || hibernation_test(TEST_DEVICES))
411 platform_recover(platform_mode);
412 else
413 error = create_image(platform_mode);
414
415 /*
416 * In the case that we call create_image() above, the control
417 * returns here (1) after the image has been created or the
418 * image creation has failed and (2) after a successful restore.
419 */
420
421 /* We may need to release the preallocated image pages here. */
422 if (error || !in_suspend)
423 swsusp_free();
424
425 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
426 dpm_resume(msg);
427
428 if (error || !in_suspend)
429 pm_restore_gfp_mask();
430
431 resume_console();
432 dpm_complete(msg);
433
434 Close:
435 platform_end(platform_mode);
436 return error;
437
438 Thaw:
439 thaw_kernel_threads();
440 Cleanup:
441 swsusp_free();
442 goto Close;
443}
444
445int __weak hibernate_resume_nonboot_cpu_disable(void)
446{
447 return suspend_disable_secondary_cpus();
448}
449
450/**
451 * resume_target_kernel - Restore system state from a hibernation image.
452 * @platform_mode: Whether or not to use the platform driver.
453 *
454 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
455 * contents of highmem that have not been restored yet from the image and run
456 * the low-level code that will restore the remaining contents of memory and
457 * switch to the just restored target kernel.
458 */
459static int resume_target_kernel(bool platform_mode)
460{
461 int error;
462
463 error = dpm_suspend_end(PMSG_QUIESCE);
464 if (error) {
465 pr_err("Some devices failed to power down, aborting resume\n");
466 return error;
467 }
468
469 error = platform_pre_restore(platform_mode);
470 if (error)
471 goto Cleanup;
472
473 cpuidle_pause();
474
475 error = hibernate_resume_nonboot_cpu_disable();
476 if (error)
477 goto Enable_cpus;
478
479 local_irq_disable();
480 system_state = SYSTEM_SUSPEND;
481
482 error = syscore_suspend();
483 if (error)
484 goto Enable_irqs;
485
486 save_processor_state();
487 error = restore_highmem();
488 if (!error) {
489 error = swsusp_arch_resume();
490 /*
491 * The code below is only ever reached in case of a failure.
492 * Otherwise, execution continues at the place where
493 * swsusp_arch_suspend() was called.
494 */
495 BUG_ON(!error);
496 /*
497 * This call to restore_highmem() reverts the changes made by
498 * the previous one.
499 */
500 restore_highmem();
501 }
502 /*
503 * The only reason why swsusp_arch_resume() can fail is memory being
504 * very tight, so we have to free it as soon as we can to avoid
505 * subsequent failures.
506 */
507 swsusp_free();
508 restore_processor_state();
509 touch_softlockup_watchdog();
510
511 syscore_resume();
512
513 Enable_irqs:
514 system_state = SYSTEM_RUNNING;
515 local_irq_enable();
516
517 Enable_cpus:
518 pm_sleep_enable_secondary_cpus();
519
520 Cleanup:
521 platform_restore_cleanup(platform_mode);
522
523 dpm_resume_start(PMSG_RECOVER);
524
525 return error;
526}
527
528/**
529 * hibernation_restore - Quiesce devices and restore from a hibernation image.
530 * @platform_mode: If set, use platform driver to prepare for the transition.
531 *
532 * This routine must be called with system_transition_mutex held. If it is
533 * successful, control reappears in the restored target kernel in
534 * hibernation_snapshot().
535 */
536int hibernation_restore(int platform_mode)
537{
538 int error;
539
540 pm_prepare_console();
541 suspend_console();
542 pm_restrict_gfp_mask();
543 error = dpm_suspend_start(PMSG_QUIESCE);
544 if (!error) {
545 error = resume_target_kernel(platform_mode);
546 /*
547 * The above should either succeed and jump to the new kernel,
548 * or return with an error. Otherwise things are just
549 * undefined, so let's be paranoid.
550 */
551 BUG_ON(!error);
552 }
553 dpm_resume_end(PMSG_RECOVER);
554 pm_restore_gfp_mask();
555 resume_console();
556 pm_restore_console();
557 return error;
558}
559
560/**
561 * hibernation_platform_enter - Power off the system using the platform driver.
562 */
563int hibernation_platform_enter(void)
564{
565 int error;
566
567 if (!hibernation_ops)
568 return -ENOSYS;
569
570 /*
571 * We have cancelled the power transition by running
572 * hibernation_ops->finish() before saving the image, so we should let
573 * the firmware know that we're going to enter the sleep state after all
574 */
575 error = hibernation_ops->begin(PMSG_HIBERNATE);
576 if (error)
577 goto Close;
578
579 entering_platform_hibernation = true;
580 suspend_console();
581 error = dpm_suspend_start(PMSG_HIBERNATE);
582 if (error) {
583 if (hibernation_ops->recover)
584 hibernation_ops->recover();
585 goto Resume_devices;
586 }
587
588 error = dpm_suspend_end(PMSG_HIBERNATE);
589 if (error)
590 goto Resume_devices;
591
592 error = hibernation_ops->prepare();
593 if (error)
594 goto Platform_finish;
595
596 error = pm_sleep_disable_secondary_cpus();
597 if (error)
598 goto Enable_cpus;
599
600 local_irq_disable();
601 system_state = SYSTEM_SUSPEND;
602 syscore_suspend();
603 if (pm_wakeup_pending()) {
604 error = -EAGAIN;
605 goto Power_up;
606 }
607
608 hibernation_ops->enter();
609 /* We should never get here */
610 while (1);
611
612 Power_up:
613 syscore_resume();
614 system_state = SYSTEM_RUNNING;
615 local_irq_enable();
616
617 Enable_cpus:
618 pm_sleep_enable_secondary_cpus();
619
620 Platform_finish:
621 hibernation_ops->finish();
622
623 dpm_resume_start(PMSG_RESTORE);
624
625 Resume_devices:
626 entering_platform_hibernation = false;
627 dpm_resume_end(PMSG_RESTORE);
628 resume_console();
629
630 Close:
631 hibernation_ops->end();
632
633 return error;
634}
635
636/**
637 * power_down - Shut the machine down for hibernation.
638 *
639 * Use the platform driver, if configured, to put the system into the sleep
640 * state corresponding to hibernation, or try to power it off or reboot,
641 * depending on the value of hibernation_mode.
642 */
643static void power_down(void)
644{
645 int error;
646
647#ifdef CONFIG_SUSPEND
648 if (hibernation_mode == HIBERNATION_SUSPEND) {
649 error = suspend_devices_and_enter(mem_sleep_current);
650 if (error) {
651 hibernation_mode = hibernation_ops ?
652 HIBERNATION_PLATFORM :
653 HIBERNATION_SHUTDOWN;
654 } else {
655 /* Restore swap signature. */
656 error = swsusp_unmark();
657 if (error)
658 pr_err("Swap will be unusable! Try swapon -a.\n");
659
660 return;
661 }
662 }
663#endif
664
665 switch (hibernation_mode) {
666 case HIBERNATION_REBOOT:
667 kernel_restart(NULL);
668 break;
669 case HIBERNATION_PLATFORM:
670 error = hibernation_platform_enter();
671 if (error == -EAGAIN || error == -EBUSY) {
672 swsusp_unmark();
673 events_check_enabled = false;
674 pr_info("Wakeup event detected during hibernation, rolling back.\n");
675 return;
676 }
677 fallthrough;
678 case HIBERNATION_SHUTDOWN:
679 if (kernel_can_power_off())
680 kernel_power_off();
681 break;
682 }
683 kernel_halt();
684 /*
685 * Valid image is on the disk, if we continue we risk serious data
686 * corruption after resume.
687 */
688 pr_crit("Power down manually\n");
689 while (1)
690 cpu_relax();
691}
692
693static int load_image_and_restore(void)
694{
695 int error;
696 unsigned int flags;
697
698 pm_pr_dbg("Loading hibernation image.\n");
699
700 lock_device_hotplug();
701 error = create_basic_memory_bitmaps();
702 if (error) {
703 swsusp_close();
704 goto Unlock;
705 }
706
707 error = swsusp_read(&flags);
708 swsusp_close();
709 if (!error)
710 error = hibernation_restore(flags & SF_PLATFORM_MODE);
711
712 pr_err("Failed to load image, recovering.\n");
713 swsusp_free();
714 free_basic_memory_bitmaps();
715 Unlock:
716 unlock_device_hotplug();
717
718 return error;
719}
720
721/**
722 * hibernate - Carry out system hibernation, including saving the image.
723 */
724int hibernate(void)
725{
726 bool snapshot_test = false;
727 unsigned int sleep_flags;
728 int error;
729
730 if (!hibernation_available()) {
731 pm_pr_dbg("Hibernation not available.\n");
732 return -EPERM;
733 }
734
735 sleep_flags = lock_system_sleep();
736 /* The snapshot device should not be opened while we're running */
737 if (!hibernate_acquire()) {
738 error = -EBUSY;
739 goto Unlock;
740 }
741
742 pr_info("hibernation entry\n");
743 pm_prepare_console();
744 error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
745 if (error)
746 goto Restore;
747
748 ksys_sync_helper();
749
750 error = freeze_processes();
751 if (error)
752 goto Exit;
753
754 lock_device_hotplug();
755 /* Allocate memory management structures */
756 error = create_basic_memory_bitmaps();
757 if (error)
758 goto Thaw;
759
760 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
761 if (error || freezer_test_done)
762 goto Free_bitmaps;
763
764 if (in_suspend) {
765 unsigned int flags = 0;
766
767 if (hibernation_mode == HIBERNATION_PLATFORM)
768 flags |= SF_PLATFORM_MODE;
769 if (nocompress)
770 flags |= SF_NOCOMPRESS_MODE;
771 else
772 flags |= SF_CRC32_MODE;
773
774 pm_pr_dbg("Writing hibernation image.\n");
775 error = swsusp_write(flags);
776 swsusp_free();
777 if (!error) {
778 if (hibernation_mode == HIBERNATION_TEST_RESUME)
779 snapshot_test = true;
780 else
781 power_down();
782 }
783 in_suspend = 0;
784 pm_restore_gfp_mask();
785 } else {
786 pm_pr_dbg("Hibernation image restored successfully.\n");
787 }
788
789 Free_bitmaps:
790 free_basic_memory_bitmaps();
791 Thaw:
792 unlock_device_hotplug();
793 if (snapshot_test) {
794 pm_pr_dbg("Checking hibernation image\n");
795 error = swsusp_check(false);
796 if (!error)
797 error = load_image_and_restore();
798 }
799 thaw_processes();
800
801 /* Don't bother checking whether freezer_test_done is true */
802 freezer_test_done = false;
803 Exit:
804 pm_notifier_call_chain(PM_POST_HIBERNATION);
805 Restore:
806 pm_restore_console();
807 hibernate_release();
808 Unlock:
809 unlock_system_sleep(sleep_flags);
810 pr_info("hibernation exit\n");
811
812 return error;
813}
814
815/**
816 * hibernate_quiet_exec - Execute a function with all devices frozen.
817 * @func: Function to execute.
818 * @data: Data pointer to pass to @func.
819 *
820 * Return the @func return value or an error code if it cannot be executed.
821 */
822int hibernate_quiet_exec(int (*func)(void *data), void *data)
823{
824 unsigned int sleep_flags;
825 int error;
826
827 sleep_flags = lock_system_sleep();
828
829 if (!hibernate_acquire()) {
830 error = -EBUSY;
831 goto unlock;
832 }
833
834 pm_prepare_console();
835
836 error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
837 if (error)
838 goto restore;
839
840 error = freeze_processes();
841 if (error)
842 goto exit;
843
844 lock_device_hotplug();
845
846 pm_suspend_clear_flags();
847
848 error = platform_begin(true);
849 if (error)
850 goto thaw;
851
852 error = freeze_kernel_threads();
853 if (error)
854 goto thaw;
855
856 error = dpm_prepare(PMSG_FREEZE);
857 if (error)
858 goto dpm_complete;
859
860 suspend_console();
861
862 error = dpm_suspend(PMSG_FREEZE);
863 if (error)
864 goto dpm_resume;
865
866 error = dpm_suspend_end(PMSG_FREEZE);
867 if (error)
868 goto dpm_resume;
869
870 error = platform_pre_snapshot(true);
871 if (error)
872 goto skip;
873
874 error = func(data);
875
876skip:
877 platform_finish(true);
878
879 dpm_resume_start(PMSG_THAW);
880
881dpm_resume:
882 dpm_resume(PMSG_THAW);
883
884 resume_console();
885
886dpm_complete:
887 dpm_complete(PMSG_THAW);
888
889 thaw_kernel_threads();
890
891thaw:
892 platform_end(true);
893
894 unlock_device_hotplug();
895
896 thaw_processes();
897
898exit:
899 pm_notifier_call_chain(PM_POST_HIBERNATION);
900
901restore:
902 pm_restore_console();
903
904 hibernate_release();
905
906unlock:
907 unlock_system_sleep(sleep_flags);
908
909 return error;
910}
911EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
912
913static int __init find_resume_device(void)
914{
915 if (!strlen(resume_file))
916 return -ENOENT;
917
918 pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
919
920 if (resume_delay) {
921 pr_info("Waiting %dsec before reading resume device ...\n",
922 resume_delay);
923 ssleep(resume_delay);
924 }
925
926 /* Check if the device is there */
927 if (!early_lookup_bdev(resume_file, &swsusp_resume_device))
928 return 0;
929
930 /*
931 * Some device discovery might still be in progress; we need to wait for
932 * this to finish.
933 */
934 wait_for_device_probe();
935 if (resume_wait) {
936 while (early_lookup_bdev(resume_file, &swsusp_resume_device))
937 msleep(10);
938 async_synchronize_full();
939 }
940
941 return early_lookup_bdev(resume_file, &swsusp_resume_device);
942}
943
944static int software_resume(void)
945{
946 int error;
947
948 pm_pr_dbg("Hibernation image partition %d:%d present\n",
949 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
950
951 pm_pr_dbg("Looking for hibernation image.\n");
952
953 mutex_lock(&system_transition_mutex);
954 error = swsusp_check(true);
955 if (error)
956 goto Unlock;
957
958 /* The snapshot device should not be opened while we're running */
959 if (!hibernate_acquire()) {
960 error = -EBUSY;
961 swsusp_close();
962 goto Unlock;
963 }
964
965 pr_info("resume from hibernation\n");
966 pm_prepare_console();
967 error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
968 if (error)
969 goto Restore;
970
971 pm_pr_dbg("Preparing processes for hibernation restore.\n");
972 error = freeze_processes();
973 if (error)
974 goto Close_Finish;
975
976 error = freeze_kernel_threads();
977 if (error) {
978 thaw_processes();
979 goto Close_Finish;
980 }
981
982 error = load_image_and_restore();
983 thaw_processes();
984 Finish:
985 pm_notifier_call_chain(PM_POST_RESTORE);
986 Restore:
987 pm_restore_console();
988 pr_info("resume failed (%d)\n", error);
989 hibernate_release();
990 /* For success case, the suspend path will release the lock */
991 Unlock:
992 mutex_unlock(&system_transition_mutex);
993 pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
994 return error;
995 Close_Finish:
996 swsusp_close();
997 goto Finish;
998}
999
1000/**
1001 * software_resume_initcall - Resume from a saved hibernation image.
1002 *
1003 * This routine is called as a late initcall, when all devices have been
1004 * discovered and initialized already.
1005 *
1006 * The image reading code is called to see if there is a hibernation image
1007 * available for reading. If that is the case, devices are quiesced and the
1008 * contents of memory is restored from the saved image.
1009 *
1010 * If this is successful, control reappears in the restored target kernel in
1011 * hibernation_snapshot() which returns to hibernate(). Otherwise, the routine
1012 * attempts to recover gracefully and make the kernel return to the normal mode
1013 * of operation.
1014 */
1015static int __init software_resume_initcall(void)
1016{
1017 /*
1018 * If the user said "noresume".. bail out early.
1019 */
1020 if (noresume || !hibernation_available())
1021 return 0;
1022
1023 if (!swsusp_resume_device) {
1024 int error = find_resume_device();
1025
1026 if (error)
1027 return error;
1028 }
1029
1030 return software_resume();
1031}
1032late_initcall_sync(software_resume_initcall);
1033
1034
1035static const char * const hibernation_modes[] = {
1036 [HIBERNATION_PLATFORM] = "platform",
1037 [HIBERNATION_SHUTDOWN] = "shutdown",
1038 [HIBERNATION_REBOOT] = "reboot",
1039#ifdef CONFIG_SUSPEND
1040 [HIBERNATION_SUSPEND] = "suspend",
1041#endif
1042 [HIBERNATION_TEST_RESUME] = "test_resume",
1043};
1044
1045/*
1046 * /sys/power/disk - Control hibernation mode.
1047 *
1048 * Hibernation can be handled in several ways. There are a few different ways
1049 * to put the system into the sleep state: using the platform driver (e.g. ACPI
1050 * or other hibernation_ops), powering it off or rebooting it (for testing
1051 * mostly).
1052 *
1053 * The sysfs file /sys/power/disk provides an interface for selecting the
1054 * hibernation mode to use. Reading from this file causes the available modes
1055 * to be printed. There are 3 modes that can be supported:
1056 *
1057 * 'platform'
1058 * 'shutdown'
1059 * 'reboot'
1060 *
1061 * If a platform hibernation driver is in use, 'platform' will be supported
1062 * and will be used by default. Otherwise, 'shutdown' will be used by default.
1063 * The selected option (i.e. the one corresponding to the current value of
1064 * hibernation_mode) is enclosed by a square bracket.
1065 *
1066 * To select a given hibernation mode it is necessary to write the mode's
1067 * string representation (as returned by reading from /sys/power/disk) back
1068 * into /sys/power/disk.
1069 */
1070
1071static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1072 char *buf)
1073{
1074 int i;
1075 char *start = buf;
1076
1077 if (!hibernation_available())
1078 return sprintf(buf, "[disabled]\n");
1079
1080 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1081 if (!hibernation_modes[i])
1082 continue;
1083 switch (i) {
1084 case HIBERNATION_SHUTDOWN:
1085 case HIBERNATION_REBOOT:
1086#ifdef CONFIG_SUSPEND
1087 case HIBERNATION_SUSPEND:
1088#endif
1089 case HIBERNATION_TEST_RESUME:
1090 break;
1091 case HIBERNATION_PLATFORM:
1092 if (hibernation_ops)
1093 break;
1094 /* not a valid mode, continue with loop */
1095 continue;
1096 }
1097 if (i == hibernation_mode)
1098 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
1099 else
1100 buf += sprintf(buf, "%s ", hibernation_modes[i]);
1101 }
1102 buf += sprintf(buf, "\n");
1103 return buf-start;
1104}
1105
1106static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1107 const char *buf, size_t n)
1108{
1109 int mode = HIBERNATION_INVALID;
1110 unsigned int sleep_flags;
1111 int error = 0;
1112 int len;
1113 char *p;
1114 int i;
1115
1116 if (!hibernation_available())
1117 return -EPERM;
1118
1119 p = memchr(buf, '\n', n);
1120 len = p ? p - buf : n;
1121
1122 sleep_flags = lock_system_sleep();
1123 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1124 if (len == strlen(hibernation_modes[i])
1125 && !strncmp(buf, hibernation_modes[i], len)) {
1126 mode = i;
1127 break;
1128 }
1129 }
1130 if (mode != HIBERNATION_INVALID) {
1131 switch (mode) {
1132 case HIBERNATION_SHUTDOWN:
1133 case HIBERNATION_REBOOT:
1134#ifdef CONFIG_SUSPEND
1135 case HIBERNATION_SUSPEND:
1136#endif
1137 case HIBERNATION_TEST_RESUME:
1138 hibernation_mode = mode;
1139 break;
1140 case HIBERNATION_PLATFORM:
1141 if (hibernation_ops)
1142 hibernation_mode = mode;
1143 else
1144 error = -EINVAL;
1145 }
1146 } else
1147 error = -EINVAL;
1148
1149 if (!error)
1150 pm_pr_dbg("Hibernation mode set to '%s'\n",
1151 hibernation_modes[mode]);
1152 unlock_system_sleep(sleep_flags);
1153 return error ? error : n;
1154}
1155
1156power_attr(disk);
1157
1158static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1159 char *buf)
1160{
1161 return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1162 MINOR(swsusp_resume_device));
1163}
1164
1165static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1166 const char *buf, size_t n)
1167{
1168 unsigned int sleep_flags;
1169 int len = n;
1170 char *name;
1171 dev_t dev;
1172 int error;
1173
1174 if (!hibernation_available())
1175 return n;
1176
1177 if (len && buf[len-1] == '\n')
1178 len--;
1179 name = kstrndup(buf, len, GFP_KERNEL);
1180 if (!name)
1181 return -ENOMEM;
1182
1183 error = lookup_bdev(name, &dev);
1184 if (error) {
1185 unsigned maj, min, offset;
1186 char *p, dummy;
1187
1188 error = 0;
1189 if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 ||
1190 sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset,
1191 &dummy) == 3) {
1192 dev = MKDEV(maj, min);
1193 if (maj != MAJOR(dev) || min != MINOR(dev))
1194 error = -EINVAL;
1195 } else {
1196 dev = new_decode_dev(simple_strtoul(name, &p, 16));
1197 if (*p)
1198 error = -EINVAL;
1199 }
1200 }
1201 kfree(name);
1202 if (error)
1203 return error;
1204
1205 sleep_flags = lock_system_sleep();
1206 swsusp_resume_device = dev;
1207 unlock_system_sleep(sleep_flags);
1208
1209 pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1210 swsusp_resume_device);
1211 noresume = 0;
1212 software_resume();
1213 return n;
1214}
1215
1216power_attr(resume);
1217
1218static ssize_t resume_offset_show(struct kobject *kobj,
1219 struct kobj_attribute *attr, char *buf)
1220{
1221 return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1222}
1223
1224static ssize_t resume_offset_store(struct kobject *kobj,
1225 struct kobj_attribute *attr, const char *buf,
1226 size_t n)
1227{
1228 unsigned long long offset;
1229 int rc;
1230
1231 rc = kstrtoull(buf, 0, &offset);
1232 if (rc)
1233 return rc;
1234 swsusp_resume_block = offset;
1235
1236 return n;
1237}
1238
1239power_attr(resume_offset);
1240
1241static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1242 char *buf)
1243{
1244 return sprintf(buf, "%lu\n", image_size);
1245}
1246
1247static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1248 const char *buf, size_t n)
1249{
1250 unsigned long size;
1251
1252 if (sscanf(buf, "%lu", &size) == 1) {
1253 image_size = size;
1254 return n;
1255 }
1256
1257 return -EINVAL;
1258}
1259
1260power_attr(image_size);
1261
1262static ssize_t reserved_size_show(struct kobject *kobj,
1263 struct kobj_attribute *attr, char *buf)
1264{
1265 return sprintf(buf, "%lu\n", reserved_size);
1266}
1267
1268static ssize_t reserved_size_store(struct kobject *kobj,
1269 struct kobj_attribute *attr,
1270 const char *buf, size_t n)
1271{
1272 unsigned long size;
1273
1274 if (sscanf(buf, "%lu", &size) == 1) {
1275 reserved_size = size;
1276 return n;
1277 }
1278
1279 return -EINVAL;
1280}
1281
1282power_attr(reserved_size);
1283
1284static struct attribute *g[] = {
1285 &disk_attr.attr,
1286 &resume_offset_attr.attr,
1287 &resume_attr.attr,
1288 &image_size_attr.attr,
1289 &reserved_size_attr.attr,
1290 NULL,
1291};
1292
1293
1294static const struct attribute_group attr_group = {
1295 .attrs = g,
1296};
1297
1298
1299static int __init pm_disk_init(void)
1300{
1301 return sysfs_create_group(power_kobj, &attr_group);
1302}
1303
1304core_initcall(pm_disk_init);
1305
1306
1307static int __init resume_setup(char *str)
1308{
1309 if (noresume)
1310 return 1;
1311
1312 strncpy(resume_file, str, 255);
1313 return 1;
1314}
1315
1316static int __init resume_offset_setup(char *str)
1317{
1318 unsigned long long offset;
1319
1320 if (noresume)
1321 return 1;
1322
1323 if (sscanf(str, "%llu", &offset) == 1)
1324 swsusp_resume_block = offset;
1325
1326 return 1;
1327}
1328
1329static int __init hibernate_setup(char *str)
1330{
1331 if (!strncmp(str, "noresume", 8)) {
1332 noresume = 1;
1333 } else if (!strncmp(str, "nocompress", 10)) {
1334 nocompress = 1;
1335 } else if (!strncmp(str, "no", 2)) {
1336 noresume = 1;
1337 nohibernate = 1;
1338 } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1339 && !strncmp(str, "protect_image", 13)) {
1340 enable_restore_image_protection();
1341 }
1342 return 1;
1343}
1344
1345static int __init noresume_setup(char *str)
1346{
1347 noresume = 1;
1348 return 1;
1349}
1350
1351static int __init resumewait_setup(char *str)
1352{
1353 resume_wait = 1;
1354 return 1;
1355}
1356
1357static int __init resumedelay_setup(char *str)
1358{
1359 int rc = kstrtouint(str, 0, &resume_delay);
1360
1361 if (rc)
1362 pr_warn("resumedelay: bad option string '%s'\n", str);
1363 return 1;
1364}
1365
1366static int __init nohibernate_setup(char *str)
1367{
1368 noresume = 1;
1369 nohibernate = 1;
1370 return 1;
1371}
1372
1373__setup("noresume", noresume_setup);
1374__setup("resume_offset=", resume_offset_setup);
1375__setup("resume=", resume_setup);
1376__setup("hibernate=", hibernate_setup);
1377__setup("resumewait", resumewait_setup);
1378__setup("resumedelay=", resumedelay_setup);
1379__setup("nohibernate", nohibernate_setup);