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