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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/*
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);