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