Merge tag 'iomap-6.6-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
[platform/kernel/linux-starfive.git] / kernel / power / hibernate.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
4  *
5  * Copyright (c) 2003 Patrick Mochel
6  * Copyright (c) 2003 Open Source Development Lab
7  * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
8  * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
9  * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
10  */
11
12 #define pr_fmt(fmt) "PM: hibernation: " fmt
13
14 #include <linux/blkdev.h>
15 #include <linux/export.h>
16 #include <linux/suspend.h>
17 #include <linux/reboot.h>
18 #include <linux/string.h>
19 #include <linux/device.h>
20 #include <linux/async.h>
21 #include <linux/delay.h>
22 #include <linux/fs.h>
23 #include <linux/mount.h>
24 #include <linux/pm.h>
25 #include <linux/nmi.h>
26 #include <linux/console.h>
27 #include <linux/cpu.h>
28 #include <linux/freezer.h>
29 #include <linux/gfp.h>
30 #include <linux/syscore_ops.h>
31 #include <linux/ctype.h>
32 #include <linux/ktime.h>
33 #include <linux/security.h>
34 #include <linux/secretmem.h>
35 #include <trace/events/power.h>
36
37 #include "power.h"
38
39
40 static int nocompress;
41 static int noresume;
42 static int nohibernate;
43 static int resume_wait;
44 static unsigned int resume_delay;
45 static char resume_file[256] = CONFIG_PM_STD_PARTITION;
46 dev_t swsusp_resume_device;
47 sector_t swsusp_resume_block;
48 __visible int in_suspend __nosavedata;
49
50 enum {
51         HIBERNATION_INVALID,
52         HIBERNATION_PLATFORM,
53         HIBERNATION_SHUTDOWN,
54         HIBERNATION_REBOOT,
55 #ifdef CONFIG_SUSPEND
56         HIBERNATION_SUSPEND,
57 #endif
58         HIBERNATION_TEST_RESUME,
59         /* keep last */
60         __HIBERNATION_AFTER_LAST
61 };
62 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
63 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
64
65 static int hibernation_mode = HIBERNATION_SHUTDOWN;
66
67 bool freezer_test_done;
68
69 static const struct platform_hibernation_ops *hibernation_ops;
70
71 static atomic_t hibernate_atomic = ATOMIC_INIT(1);
72
73 bool hibernate_acquire(void)
74 {
75         return atomic_add_unless(&hibernate_atomic, -1, 0);
76 }
77
78 void hibernate_release(void)
79 {
80         atomic_inc(&hibernate_atomic);
81 }
82
83 bool hibernation_available(void)
84 {
85         return nohibernate == 0 &&
86                 !security_locked_down(LOCKDOWN_HIBERNATION) &&
87                 !secretmem_active() && !cxl_mem_active();
88 }
89
90 /**
91  * hibernation_set_ops - Set the global hibernate operations.
92  * @ops: Hibernation operations to use in subsequent hibernation transitions.
93  */
94 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
95 {
96         unsigned int sleep_flags;
97
98         if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
99             && ops->prepare && ops->finish && ops->enter && ops->pre_restore
100             && ops->restore_cleanup && ops->leave)) {
101                 WARN_ON(1);
102                 return;
103         }
104
105         sleep_flags = lock_system_sleep();
106
107         hibernation_ops = ops;
108         if (ops)
109                 hibernation_mode = HIBERNATION_PLATFORM;
110         else if (hibernation_mode == HIBERNATION_PLATFORM)
111                 hibernation_mode = HIBERNATION_SHUTDOWN;
112
113         unlock_system_sleep(sleep_flags);
114 }
115 EXPORT_SYMBOL_GPL(hibernation_set_ops);
116
117 static bool entering_platform_hibernation;
118
119 bool system_entering_hibernation(void)
120 {
121         return entering_platform_hibernation;
122 }
123 EXPORT_SYMBOL(system_entering_hibernation);
124
125 #ifdef CONFIG_PM_DEBUG
126 static void hibernation_debug_sleep(void)
127 {
128         pr_info("debug: Waiting for 5 seconds.\n");
129         mdelay(5000);
130 }
131
132 static int hibernation_test(int level)
133 {
134         if (pm_test_level == level) {
135                 hibernation_debug_sleep();
136                 return 1;
137         }
138         return 0;
139 }
140 #else /* !CONFIG_PM_DEBUG */
141 static int hibernation_test(int level) { return 0; }
142 #endif /* !CONFIG_PM_DEBUG */
143
144 /**
145  * platform_begin - Call platform to start hibernation.
146  * @platform_mode: Whether or not to use the platform driver.
147  */
148 static int platform_begin(int platform_mode)
149 {
150         return (platform_mode && hibernation_ops) ?
151                 hibernation_ops->begin(PMSG_FREEZE) : 0;
152 }
153
154 /**
155  * platform_end - Call platform to finish transition to the working state.
156  * @platform_mode: Whether or not to use the platform driver.
157  */
158 static void platform_end(int platform_mode)
159 {
160         if (platform_mode && hibernation_ops)
161                 hibernation_ops->end();
162 }
163
164 /**
165  * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
166  * @platform_mode: Whether or not to use the platform driver.
167  *
168  * Use the platform driver to prepare the system for creating a hibernate image,
169  * if so configured, and return an error code if that fails.
170  */
171
172 static int platform_pre_snapshot(int platform_mode)
173 {
174         return (platform_mode && hibernation_ops) ?
175                 hibernation_ops->pre_snapshot() : 0;
176 }
177
178 /**
179  * platform_leave - Call platform to prepare a transition to the working state.
180  * @platform_mode: Whether or not to use the platform driver.
181  *
182  * Use the platform driver prepare to prepare the machine for switching to the
183  * normal mode of operation.
184  *
185  * This routine is called on one CPU with interrupts disabled.
186  */
187 static void platform_leave(int platform_mode)
188 {
189         if (platform_mode && hibernation_ops)
190                 hibernation_ops->leave();
191 }
192
193 /**
194  * platform_finish - Call platform to switch the system to the working state.
195  * @platform_mode: Whether or not to use the platform driver.
196  *
197  * Use the platform driver to switch the machine to the normal mode of
198  * operation.
199  *
200  * This routine must be called after platform_prepare().
201  */
202 static void platform_finish(int platform_mode)
203 {
204         if (platform_mode && hibernation_ops)
205                 hibernation_ops->finish();
206 }
207
208 /**
209  * platform_pre_restore - Prepare for hibernate image restoration.
210  * @platform_mode: Whether or not to use the platform driver.
211  *
212  * Use the platform driver to prepare the system for resume from a hibernation
213  * image.
214  *
215  * If the restore fails after this function has been called,
216  * platform_restore_cleanup() must be called.
217  */
218 static int platform_pre_restore(int platform_mode)
219 {
220         return (platform_mode && hibernation_ops) ?
221                 hibernation_ops->pre_restore() : 0;
222 }
223
224 /**
225  * platform_restore_cleanup - Switch to the working state after failing restore.
226  * @platform_mode: Whether or not to use the platform driver.
227  *
228  * Use the platform driver to switch the system to the normal mode of operation
229  * after a failing restore.
230  *
231  * If platform_pre_restore() has been called before the failing restore, this
232  * function must be called too, regardless of the result of
233  * platform_pre_restore().
234  */
235 static void platform_restore_cleanup(int platform_mode)
236 {
237         if (platform_mode && hibernation_ops)
238                 hibernation_ops->restore_cleanup();
239 }
240
241 /**
242  * platform_recover - Recover from a failure to suspend devices.
243  * @platform_mode: Whether or not to use the platform driver.
244  */
245 static void platform_recover(int platform_mode)
246 {
247         if (platform_mode && hibernation_ops && hibernation_ops->recover)
248                 hibernation_ops->recover();
249 }
250
251 /**
252  * swsusp_show_speed - Print time elapsed between two events during hibernation.
253  * @start: Starting event.
254  * @stop: Final event.
255  * @nr_pages: Number of memory pages processed between @start and @stop.
256  * @msg: Additional diagnostic message to print.
257  */
258 void swsusp_show_speed(ktime_t start, ktime_t stop,
259                       unsigned nr_pages, char *msg)
260 {
261         ktime_t diff;
262         u64 elapsed_centisecs64;
263         unsigned int centisecs;
264         unsigned int k;
265         unsigned int kps;
266
267         diff = ktime_sub(stop, start);
268         elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
269         centisecs = elapsed_centisecs64;
270         if (centisecs == 0)
271                 centisecs = 1;  /* avoid div-by-zero */
272         k = nr_pages * (PAGE_SIZE / 1024);
273         kps = (k * 100) / centisecs;
274         pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
275                 msg, k, centisecs / 100, centisecs % 100, kps / 1000,
276                 (kps % 1000) / 10);
277 }
278
279 __weak int arch_resume_nosmt(void)
280 {
281         return 0;
282 }
283
284 /**
285  * create_image - Create a hibernation image.
286  * @platform_mode: Whether or not to use the platform driver.
287  *
288  * Execute device drivers' "late" and "noirq" freeze callbacks, create a
289  * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
290  *
291  * Control reappears in this routine after the subsequent restore.
292  */
293 static int create_image(int platform_mode)
294 {
295         int error;
296
297         error = dpm_suspend_end(PMSG_FREEZE);
298         if (error) {
299                 pr_err("Some devices failed to power down, aborting\n");
300                 return error;
301         }
302
303         error = platform_pre_snapshot(platform_mode);
304         if (error || hibernation_test(TEST_PLATFORM))
305                 goto Platform_finish;
306
307         error = pm_sleep_disable_secondary_cpus();
308         if (error || hibernation_test(TEST_CPUS))
309                 goto Enable_cpus;
310
311         local_irq_disable();
312
313         system_state = SYSTEM_SUSPEND;
314
315         error = syscore_suspend();
316         if (error) {
317                 pr_err("Some system devices failed to power down, aborting\n");
318                 goto Enable_irqs;
319         }
320
321         if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
322                 goto Power_up;
323
324         in_suspend = 1;
325         save_processor_state();
326         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
327         error = swsusp_arch_suspend();
328         /* Restore control flow magically appears here */
329         restore_processor_state();
330         trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
331         if (error)
332                 pr_err("Error %d creating image\n", error);
333
334         if (!in_suspend) {
335                 events_check_enabled = false;
336                 clear_or_poison_free_pages();
337         }
338
339         platform_leave(platform_mode);
340
341  Power_up:
342         syscore_resume();
343
344  Enable_irqs:
345         system_state = SYSTEM_RUNNING;
346         local_irq_enable();
347
348  Enable_cpus:
349         pm_sleep_enable_secondary_cpus();
350
351         /* Allow architectures to do nosmt-specific post-resume dances */
352         if (!in_suspend)
353                 error = arch_resume_nosmt();
354
355  Platform_finish:
356         platform_finish(platform_mode);
357
358         dpm_resume_start(in_suspend ?
359                 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
360
361         return error;
362 }
363
364 /**
365  * hibernation_snapshot - Quiesce devices and create a hibernation image.
366  * @platform_mode: If set, use platform driver to prepare for the transition.
367  *
368  * This routine must be called with system_transition_mutex held.
369  */
370 int hibernation_snapshot(int platform_mode)
371 {
372         pm_message_t msg;
373         int error;
374
375         pm_suspend_clear_flags();
376         error = platform_begin(platform_mode);
377         if (error)
378                 goto Close;
379
380         /* Preallocate image memory before shutting down devices. */
381         error = hibernate_preallocate_memory();
382         if (error)
383                 goto Close;
384
385         error = freeze_kernel_threads();
386         if (error)
387                 goto Cleanup;
388
389         if (hibernation_test(TEST_FREEZER)) {
390
391                 /*
392                  * Indicate to the caller that we are returning due to a
393                  * successful freezer test.
394                  */
395                 freezer_test_done = true;
396                 goto Thaw;
397         }
398
399         error = dpm_prepare(PMSG_FREEZE);
400         if (error) {
401                 dpm_complete(PMSG_RECOVER);
402                 goto Thaw;
403         }
404
405         suspend_console();
406         pm_restrict_gfp_mask();
407
408         error = dpm_suspend(PMSG_FREEZE);
409
410         if (error || hibernation_test(TEST_DEVICES))
411                 platform_recover(platform_mode);
412         else
413                 error = create_image(platform_mode);
414
415         /*
416          * In the case that we call create_image() above, the control
417          * returns here (1) after the image has been created or the
418          * image creation has failed and (2) after a successful restore.
419          */
420
421         /* We may need to release the preallocated image pages here. */
422         if (error || !in_suspend)
423                 swsusp_free();
424
425         msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
426         dpm_resume(msg);
427
428         if (error || !in_suspend)
429                 pm_restore_gfp_mask();
430
431         resume_console();
432         dpm_complete(msg);
433
434  Close:
435         platform_end(platform_mode);
436         return error;
437
438  Thaw:
439         thaw_kernel_threads();
440  Cleanup:
441         swsusp_free();
442         goto Close;
443 }
444
445 int __weak hibernate_resume_nonboot_cpu_disable(void)
446 {
447         return suspend_disable_secondary_cpus();
448 }
449
450 /**
451  * resume_target_kernel - Restore system state from a hibernation image.
452  * @platform_mode: Whether or not to use the platform driver.
453  *
454  * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
455  * contents of highmem that have not been restored yet from the image and run
456  * the low-level code that will restore the remaining contents of memory and
457  * switch to the just restored target kernel.
458  */
459 static int resume_target_kernel(bool platform_mode)
460 {
461         int error;
462
463         error = dpm_suspend_end(PMSG_QUIESCE);
464         if (error) {
465                 pr_err("Some devices failed to power down, aborting resume\n");
466                 return error;
467         }
468
469         error = platform_pre_restore(platform_mode);
470         if (error)
471                 goto Cleanup;
472
473         cpuidle_pause();
474
475         error = hibernate_resume_nonboot_cpu_disable();
476         if (error)
477                 goto Enable_cpus;
478
479         local_irq_disable();
480         system_state = SYSTEM_SUSPEND;
481
482         error = syscore_suspend();
483         if (error)
484                 goto Enable_irqs;
485
486         save_processor_state();
487         error = restore_highmem();
488         if (!error) {
489                 error = swsusp_arch_resume();
490                 /*
491                  * The code below is only ever reached in case of a failure.
492                  * Otherwise, execution continues at the place where
493                  * swsusp_arch_suspend() was called.
494                  */
495                 BUG_ON(!error);
496                 /*
497                  * This call to restore_highmem() reverts the changes made by
498                  * the previous one.
499                  */
500                 restore_highmem();
501         }
502         /*
503          * The only reason why swsusp_arch_resume() can fail is memory being
504          * very tight, so we have to free it as soon as we can to avoid
505          * subsequent failures.
506          */
507         swsusp_free();
508         restore_processor_state();
509         touch_softlockup_watchdog();
510
511         syscore_resume();
512
513  Enable_irqs:
514         system_state = SYSTEM_RUNNING;
515         local_irq_enable();
516
517  Enable_cpus:
518         pm_sleep_enable_secondary_cpus();
519
520  Cleanup:
521         platform_restore_cleanup(platform_mode);
522
523         dpm_resume_start(PMSG_RECOVER);
524
525         return error;
526 }
527
528 /**
529  * hibernation_restore - Quiesce devices and restore from a hibernation image.
530  * @platform_mode: If set, use platform driver to prepare for the transition.
531  *
532  * This routine must be called with system_transition_mutex held.  If it is
533  * successful, control reappears in the restored target kernel in
534  * hibernation_snapshot().
535  */
536 int hibernation_restore(int platform_mode)
537 {
538         int error;
539
540         pm_prepare_console();
541         suspend_console();
542         pm_restrict_gfp_mask();
543         error = dpm_suspend_start(PMSG_QUIESCE);
544         if (!error) {
545                 error = resume_target_kernel(platform_mode);
546                 /*
547                  * The above should either succeed and jump to the new kernel,
548                  * or return with an error. Otherwise things are just
549                  * undefined, so let's be paranoid.
550                  */
551                 BUG_ON(!error);
552         }
553         dpm_resume_end(PMSG_RECOVER);
554         pm_restore_gfp_mask();
555         resume_console();
556         pm_restore_console();
557         return error;
558 }
559
560 /**
561  * hibernation_platform_enter - Power off the system using the platform driver.
562  */
563 int hibernation_platform_enter(void)
564 {
565         int error;
566
567         if (!hibernation_ops)
568                 return -ENOSYS;
569
570         /*
571          * We have cancelled the power transition by running
572          * hibernation_ops->finish() before saving the image, so we should let
573          * the firmware know that we're going to enter the sleep state after all
574          */
575         error = hibernation_ops->begin(PMSG_HIBERNATE);
576         if (error)
577                 goto Close;
578
579         entering_platform_hibernation = true;
580         suspend_console();
581         error = dpm_suspend_start(PMSG_HIBERNATE);
582         if (error) {
583                 if (hibernation_ops->recover)
584                         hibernation_ops->recover();
585                 goto Resume_devices;
586         }
587
588         error = dpm_suspend_end(PMSG_HIBERNATE);
589         if (error)
590                 goto Resume_devices;
591
592         error = hibernation_ops->prepare();
593         if (error)
594                 goto Platform_finish;
595
596         error = pm_sleep_disable_secondary_cpus();
597         if (error)
598                 goto Enable_cpus;
599
600         local_irq_disable();
601         system_state = SYSTEM_SUSPEND;
602         syscore_suspend();
603         if (pm_wakeup_pending()) {
604                 error = -EAGAIN;
605                 goto Power_up;
606         }
607
608         hibernation_ops->enter();
609         /* We should never get here */
610         while (1);
611
612  Power_up:
613         syscore_resume();
614         system_state = SYSTEM_RUNNING;
615         local_irq_enable();
616
617  Enable_cpus:
618         pm_sleep_enable_secondary_cpus();
619
620  Platform_finish:
621         hibernation_ops->finish();
622
623         dpm_resume_start(PMSG_RESTORE);
624
625  Resume_devices:
626         entering_platform_hibernation = false;
627         dpm_resume_end(PMSG_RESTORE);
628         resume_console();
629
630  Close:
631         hibernation_ops->end();
632
633         return error;
634 }
635
636 /**
637  * power_down - Shut the machine down for hibernation.
638  *
639  * Use the platform driver, if configured, to put the system into the sleep
640  * state corresponding to hibernation, or try to power it off or reboot,
641  * depending on the value of hibernation_mode.
642  */
643 static void power_down(void)
644 {
645 #ifdef CONFIG_SUSPEND
646         int error;
647
648         if (hibernation_mode == HIBERNATION_SUSPEND) {
649                 error = suspend_devices_and_enter(mem_sleep_current);
650                 if (error) {
651                         hibernation_mode = hibernation_ops ?
652                                                 HIBERNATION_PLATFORM :
653                                                 HIBERNATION_SHUTDOWN;
654                 } else {
655                         /* Restore swap signature. */
656                         error = swsusp_unmark();
657                         if (error)
658                                 pr_err("Swap will be unusable! Try swapon -a.\n");
659
660                         return;
661                 }
662         }
663 #endif
664
665         switch (hibernation_mode) {
666         case HIBERNATION_REBOOT:
667                 kernel_restart(NULL);
668                 break;
669         case HIBERNATION_PLATFORM:
670                 hibernation_platform_enter();
671                 fallthrough;
672         case HIBERNATION_SHUTDOWN:
673                 if (kernel_can_power_off())
674                         kernel_power_off();
675                 break;
676         }
677         kernel_halt();
678         /*
679          * Valid image is on the disk, if we continue we risk serious data
680          * corruption after resume.
681          */
682         pr_crit("Power down manually\n");
683         while (1)
684                 cpu_relax();
685 }
686
687 static int load_image_and_restore(bool snapshot_test)
688 {
689         int error;
690         unsigned int flags;
691
692         pm_pr_dbg("Loading hibernation image.\n");
693
694         lock_device_hotplug();
695         error = create_basic_memory_bitmaps();
696         if (error) {
697                 swsusp_close(snapshot_test);
698                 goto Unlock;
699         }
700
701         error = swsusp_read(&flags);
702         swsusp_close(snapshot_test);
703         if (!error)
704                 error = hibernation_restore(flags & SF_PLATFORM_MODE);
705
706         pr_err("Failed to load image, recovering.\n");
707         swsusp_free();
708         free_basic_memory_bitmaps();
709  Unlock:
710         unlock_device_hotplug();
711
712         return error;
713 }
714
715 /**
716  * hibernate - Carry out system hibernation, including saving the image.
717  */
718 int hibernate(void)
719 {
720         bool snapshot_test = false;
721         unsigned int sleep_flags;
722         int error;
723
724         if (!hibernation_available()) {
725                 pm_pr_dbg("Hibernation not available.\n");
726                 return -EPERM;
727         }
728
729         sleep_flags = lock_system_sleep();
730         /* The snapshot device should not be opened while we're running */
731         if (!hibernate_acquire()) {
732                 error = -EBUSY;
733                 goto Unlock;
734         }
735
736         pr_info("hibernation entry\n");
737         pm_prepare_console();
738         error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
739         if (error)
740                 goto Restore;
741
742         ksys_sync_helper();
743
744         error = freeze_processes();
745         if (error)
746                 goto Exit;
747
748         lock_device_hotplug();
749         /* Allocate memory management structures */
750         error = create_basic_memory_bitmaps();
751         if (error)
752                 goto Thaw;
753
754         error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
755         if (error || freezer_test_done)
756                 goto Free_bitmaps;
757
758         if (in_suspend) {
759                 unsigned int flags = 0;
760
761                 if (hibernation_mode == HIBERNATION_PLATFORM)
762                         flags |= SF_PLATFORM_MODE;
763                 if (nocompress)
764                         flags |= SF_NOCOMPRESS_MODE;
765                 else
766                         flags |= SF_CRC32_MODE;
767
768                 pm_pr_dbg("Writing hibernation image.\n");
769                 error = swsusp_write(flags);
770                 swsusp_free();
771                 if (!error) {
772                         if (hibernation_mode == HIBERNATION_TEST_RESUME)
773                                 snapshot_test = true;
774                         else
775                                 power_down();
776                 }
777                 in_suspend = 0;
778                 pm_restore_gfp_mask();
779         } else {
780                 pm_pr_dbg("Hibernation image restored successfully.\n");
781         }
782
783  Free_bitmaps:
784         free_basic_memory_bitmaps();
785  Thaw:
786         unlock_device_hotplug();
787         if (snapshot_test) {
788                 pm_pr_dbg("Checking hibernation image\n");
789                 error = swsusp_check(false);
790                 if (!error)
791                         error = load_image_and_restore(false);
792         }
793         thaw_processes();
794
795         /* Don't bother checking whether freezer_test_done is true */
796         freezer_test_done = false;
797  Exit:
798         pm_notifier_call_chain(PM_POST_HIBERNATION);
799  Restore:
800         pm_restore_console();
801         hibernate_release();
802  Unlock:
803         unlock_system_sleep(sleep_flags);
804         pr_info("hibernation exit\n");
805
806         return error;
807 }
808
809 /**
810  * hibernate_quiet_exec - Execute a function with all devices frozen.
811  * @func: Function to execute.
812  * @data: Data pointer to pass to @func.
813  *
814  * Return the @func return value or an error code if it cannot be executed.
815  */
816 int hibernate_quiet_exec(int (*func)(void *data), void *data)
817 {
818         unsigned int sleep_flags;
819         int error;
820
821         sleep_flags = lock_system_sleep();
822
823         if (!hibernate_acquire()) {
824                 error = -EBUSY;
825                 goto unlock;
826         }
827
828         pm_prepare_console();
829
830         error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
831         if (error)
832                 goto restore;
833
834         error = freeze_processes();
835         if (error)
836                 goto exit;
837
838         lock_device_hotplug();
839
840         pm_suspend_clear_flags();
841
842         error = platform_begin(true);
843         if (error)
844                 goto thaw;
845
846         error = freeze_kernel_threads();
847         if (error)
848                 goto thaw;
849
850         error = dpm_prepare(PMSG_FREEZE);
851         if (error)
852                 goto dpm_complete;
853
854         suspend_console();
855
856         error = dpm_suspend(PMSG_FREEZE);
857         if (error)
858                 goto dpm_resume;
859
860         error = dpm_suspend_end(PMSG_FREEZE);
861         if (error)
862                 goto dpm_resume;
863
864         error = platform_pre_snapshot(true);
865         if (error)
866                 goto skip;
867
868         error = func(data);
869
870 skip:
871         platform_finish(true);
872
873         dpm_resume_start(PMSG_THAW);
874
875 dpm_resume:
876         dpm_resume(PMSG_THAW);
877
878         resume_console();
879
880 dpm_complete:
881         dpm_complete(PMSG_THAW);
882
883         thaw_kernel_threads();
884
885 thaw:
886         platform_end(true);
887
888         unlock_device_hotplug();
889
890         thaw_processes();
891
892 exit:
893         pm_notifier_call_chain(PM_POST_HIBERNATION);
894
895 restore:
896         pm_restore_console();
897
898         hibernate_release();
899
900 unlock:
901         unlock_system_sleep(sleep_flags);
902
903         return error;
904 }
905 EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
906
907 static int __init find_resume_device(void)
908 {
909         if (!strlen(resume_file))
910                 return -ENOENT;
911
912         pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
913
914         if (resume_delay) {
915                 pr_info("Waiting %dsec before reading resume device ...\n",
916                         resume_delay);
917                 ssleep(resume_delay);
918         }
919
920         /* Check if the device is there */
921         if (!early_lookup_bdev(resume_file, &swsusp_resume_device))
922                 return 0;
923
924         /*
925          * Some device discovery might still be in progress; we need to wait for
926          * this to finish.
927          */
928         wait_for_device_probe();
929         if (resume_wait) {
930                 while (early_lookup_bdev(resume_file, &swsusp_resume_device))
931                         msleep(10);
932                 async_synchronize_full();
933         }
934
935         return early_lookup_bdev(resume_file, &swsusp_resume_device);
936 }
937
938 static int software_resume(void)
939 {
940         int error;
941
942         pm_pr_dbg("Hibernation image partition %d:%d present\n",
943                 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
944
945         pm_pr_dbg("Looking for hibernation image.\n");
946
947         mutex_lock(&system_transition_mutex);
948         error = swsusp_check(true);
949         if (error)
950                 goto Unlock;
951
952         /* The snapshot device should not be opened while we're running */
953         if (!hibernate_acquire()) {
954                 error = -EBUSY;
955                 swsusp_close(true);
956                 goto Unlock;
957         }
958
959         pr_info("resume from hibernation\n");
960         pm_prepare_console();
961         error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
962         if (error)
963                 goto Restore;
964
965         pm_pr_dbg("Preparing processes for hibernation restore.\n");
966         error = freeze_processes();
967         if (error)
968                 goto Close_Finish;
969
970         error = freeze_kernel_threads();
971         if (error) {
972                 thaw_processes();
973                 goto Close_Finish;
974         }
975
976         error = load_image_and_restore(true);
977         thaw_processes();
978  Finish:
979         pm_notifier_call_chain(PM_POST_RESTORE);
980  Restore:
981         pm_restore_console();
982         pr_info("resume failed (%d)\n", error);
983         hibernate_release();
984         /* For success case, the suspend path will release the lock */
985  Unlock:
986         mutex_unlock(&system_transition_mutex);
987         pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
988         return error;
989  Close_Finish:
990         swsusp_close(true);
991         goto Finish;
992 }
993
994 /**
995  * software_resume_initcall - Resume from a saved hibernation image.
996  *
997  * This routine is called as a late initcall, when all devices have been
998  * discovered and initialized already.
999  *
1000  * The image reading code is called to see if there is a hibernation image
1001  * available for reading.  If that is the case, devices are quiesced and the
1002  * contents of memory is restored from the saved image.
1003  *
1004  * If this is successful, control reappears in the restored target kernel in
1005  * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
1006  * attempts to recover gracefully and make the kernel return to the normal mode
1007  * of operation.
1008  */
1009 static int __init software_resume_initcall(void)
1010 {
1011         /*
1012          * If the user said "noresume".. bail out early.
1013          */
1014         if (noresume || !hibernation_available())
1015                 return 0;
1016
1017         if (!swsusp_resume_device) {
1018                 int error = find_resume_device();
1019
1020                 if (error)
1021                         return error;
1022         }
1023
1024         return software_resume();
1025 }
1026 late_initcall_sync(software_resume_initcall);
1027
1028
1029 static const char * const hibernation_modes[] = {
1030         [HIBERNATION_PLATFORM]  = "platform",
1031         [HIBERNATION_SHUTDOWN]  = "shutdown",
1032         [HIBERNATION_REBOOT]    = "reboot",
1033 #ifdef CONFIG_SUSPEND
1034         [HIBERNATION_SUSPEND]   = "suspend",
1035 #endif
1036         [HIBERNATION_TEST_RESUME]       = "test_resume",
1037 };
1038
1039 /*
1040  * /sys/power/disk - Control hibernation mode.
1041  *
1042  * Hibernation can be handled in several ways.  There are a few different ways
1043  * to put the system into the sleep state: using the platform driver (e.g. ACPI
1044  * or other hibernation_ops), powering it off or rebooting it (for testing
1045  * mostly).
1046  *
1047  * The sysfs file /sys/power/disk provides an interface for selecting the
1048  * hibernation mode to use.  Reading from this file causes the available modes
1049  * to be printed.  There are 3 modes that can be supported:
1050  *
1051  *      'platform'
1052  *      'shutdown'
1053  *      'reboot'
1054  *
1055  * If a platform hibernation driver is in use, 'platform' will be supported
1056  * and will be used by default.  Otherwise, 'shutdown' will be used by default.
1057  * The selected option (i.e. the one corresponding to the current value of
1058  * hibernation_mode) is enclosed by a square bracket.
1059  *
1060  * To select a given hibernation mode it is necessary to write the mode's
1061  * string representation (as returned by reading from /sys/power/disk) back
1062  * into /sys/power/disk.
1063  */
1064
1065 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1066                          char *buf)
1067 {
1068         int i;
1069         char *start = buf;
1070
1071         if (!hibernation_available())
1072                 return sprintf(buf, "[disabled]\n");
1073
1074         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1075                 if (!hibernation_modes[i])
1076                         continue;
1077                 switch (i) {
1078                 case HIBERNATION_SHUTDOWN:
1079                 case HIBERNATION_REBOOT:
1080 #ifdef CONFIG_SUSPEND
1081                 case HIBERNATION_SUSPEND:
1082 #endif
1083                 case HIBERNATION_TEST_RESUME:
1084                         break;
1085                 case HIBERNATION_PLATFORM:
1086                         if (hibernation_ops)
1087                                 break;
1088                         /* not a valid mode, continue with loop */
1089                         continue;
1090                 }
1091                 if (i == hibernation_mode)
1092                         buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
1093                 else
1094                         buf += sprintf(buf, "%s ", hibernation_modes[i]);
1095         }
1096         buf += sprintf(buf, "\n");
1097         return buf-start;
1098 }
1099
1100 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1101                           const char *buf, size_t n)
1102 {
1103         int mode = HIBERNATION_INVALID;
1104         unsigned int sleep_flags;
1105         int error = 0;
1106         int len;
1107         char *p;
1108         int i;
1109
1110         if (!hibernation_available())
1111                 return -EPERM;
1112
1113         p = memchr(buf, '\n', n);
1114         len = p ? p - buf : n;
1115
1116         sleep_flags = lock_system_sleep();
1117         for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1118                 if (len == strlen(hibernation_modes[i])
1119                     && !strncmp(buf, hibernation_modes[i], len)) {
1120                         mode = i;
1121                         break;
1122                 }
1123         }
1124         if (mode != HIBERNATION_INVALID) {
1125                 switch (mode) {
1126                 case HIBERNATION_SHUTDOWN:
1127                 case HIBERNATION_REBOOT:
1128 #ifdef CONFIG_SUSPEND
1129                 case HIBERNATION_SUSPEND:
1130 #endif
1131                 case HIBERNATION_TEST_RESUME:
1132                         hibernation_mode = mode;
1133                         break;
1134                 case HIBERNATION_PLATFORM:
1135                         if (hibernation_ops)
1136                                 hibernation_mode = mode;
1137                         else
1138                                 error = -EINVAL;
1139                 }
1140         } else
1141                 error = -EINVAL;
1142
1143         if (!error)
1144                 pm_pr_dbg("Hibernation mode set to '%s'\n",
1145                                hibernation_modes[mode]);
1146         unlock_system_sleep(sleep_flags);
1147         return error ? error : n;
1148 }
1149
1150 power_attr(disk);
1151
1152 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1153                            char *buf)
1154 {
1155         return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1156                        MINOR(swsusp_resume_device));
1157 }
1158
1159 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1160                             const char *buf, size_t n)
1161 {
1162         unsigned int sleep_flags;
1163         int len = n;
1164         char *name;
1165         dev_t dev;
1166         int error;
1167
1168         if (!hibernation_available())
1169                 return n;
1170
1171         if (len && buf[len-1] == '\n')
1172                 len--;
1173         name = kstrndup(buf, len, GFP_KERNEL);
1174         if (!name)
1175                 return -ENOMEM;
1176
1177         error = lookup_bdev(name, &dev);
1178         if (error) {
1179                 unsigned maj, min, offset;
1180                 char *p, dummy;
1181
1182                 error = 0;
1183                 if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 ||
1184                     sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset,
1185                                 &dummy) == 3) {
1186                         dev = MKDEV(maj, min);
1187                         if (maj != MAJOR(dev) || min != MINOR(dev))
1188                                 error = -EINVAL;
1189                 } else {
1190                         dev = new_decode_dev(simple_strtoul(name, &p, 16));
1191                         if (*p)
1192                                 error = -EINVAL;
1193                 }
1194         }
1195         kfree(name);
1196         if (error)
1197                 return error;
1198
1199         sleep_flags = lock_system_sleep();
1200         swsusp_resume_device = dev;
1201         unlock_system_sleep(sleep_flags);
1202
1203         pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1204                   swsusp_resume_device);
1205         noresume = 0;
1206         software_resume();
1207         return n;
1208 }
1209
1210 power_attr(resume);
1211
1212 static ssize_t resume_offset_show(struct kobject *kobj,
1213                                   struct kobj_attribute *attr, char *buf)
1214 {
1215         return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1216 }
1217
1218 static ssize_t resume_offset_store(struct kobject *kobj,
1219                                    struct kobj_attribute *attr, const char *buf,
1220                                    size_t n)
1221 {
1222         unsigned long long offset;
1223         int rc;
1224
1225         rc = kstrtoull(buf, 0, &offset);
1226         if (rc)
1227                 return rc;
1228         swsusp_resume_block = offset;
1229
1230         return n;
1231 }
1232
1233 power_attr(resume_offset);
1234
1235 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1236                                char *buf)
1237 {
1238         return sprintf(buf, "%lu\n", image_size);
1239 }
1240
1241 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1242                                 const char *buf, size_t n)
1243 {
1244         unsigned long size;
1245
1246         if (sscanf(buf, "%lu", &size) == 1) {
1247                 image_size = size;
1248                 return n;
1249         }
1250
1251         return -EINVAL;
1252 }
1253
1254 power_attr(image_size);
1255
1256 static ssize_t reserved_size_show(struct kobject *kobj,
1257                                   struct kobj_attribute *attr, char *buf)
1258 {
1259         return sprintf(buf, "%lu\n", reserved_size);
1260 }
1261
1262 static ssize_t reserved_size_store(struct kobject *kobj,
1263                                    struct kobj_attribute *attr,
1264                                    const char *buf, size_t n)
1265 {
1266         unsigned long size;
1267
1268         if (sscanf(buf, "%lu", &size) == 1) {
1269                 reserved_size = size;
1270                 return n;
1271         }
1272
1273         return -EINVAL;
1274 }
1275
1276 power_attr(reserved_size);
1277
1278 static struct attribute *g[] = {
1279         &disk_attr.attr,
1280         &resume_offset_attr.attr,
1281         &resume_attr.attr,
1282         &image_size_attr.attr,
1283         &reserved_size_attr.attr,
1284         NULL,
1285 };
1286
1287
1288 static const struct attribute_group attr_group = {
1289         .attrs = g,
1290 };
1291
1292
1293 static int __init pm_disk_init(void)
1294 {
1295         return sysfs_create_group(power_kobj, &attr_group);
1296 }
1297
1298 core_initcall(pm_disk_init);
1299
1300
1301 static int __init resume_setup(char *str)
1302 {
1303         if (noresume)
1304                 return 1;
1305
1306         strncpy(resume_file, str, 255);
1307         return 1;
1308 }
1309
1310 static int __init resume_offset_setup(char *str)
1311 {
1312         unsigned long long offset;
1313
1314         if (noresume)
1315                 return 1;
1316
1317         if (sscanf(str, "%llu", &offset) == 1)
1318                 swsusp_resume_block = offset;
1319
1320         return 1;
1321 }
1322
1323 static int __init hibernate_setup(char *str)
1324 {
1325         if (!strncmp(str, "noresume", 8)) {
1326                 noresume = 1;
1327         } else if (!strncmp(str, "nocompress", 10)) {
1328                 nocompress = 1;
1329         } else if (!strncmp(str, "no", 2)) {
1330                 noresume = 1;
1331                 nohibernate = 1;
1332         } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1333                    && !strncmp(str, "protect_image", 13)) {
1334                 enable_restore_image_protection();
1335         }
1336         return 1;
1337 }
1338
1339 static int __init noresume_setup(char *str)
1340 {
1341         noresume = 1;
1342         return 1;
1343 }
1344
1345 static int __init resumewait_setup(char *str)
1346 {
1347         resume_wait = 1;
1348         return 1;
1349 }
1350
1351 static int __init resumedelay_setup(char *str)
1352 {
1353         int rc = kstrtouint(str, 0, &resume_delay);
1354
1355         if (rc)
1356                 pr_warn("resumedelay: bad option string '%s'\n", str);
1357         return 1;
1358 }
1359
1360 static int __init nohibernate_setup(char *str)
1361 {
1362         noresume = 1;
1363         nohibernate = 1;
1364         return 1;
1365 }
1366
1367 __setup("noresume", noresume_setup);
1368 __setup("resume_offset=", resume_offset_setup);
1369 __setup("resume=", resume_setup);
1370 __setup("hibernate=", hibernate_setup);
1371 __setup("resumewait", resumewait_setup);
1372 __setup("resumedelay=", resumedelay_setup);
1373 __setup("nohibernate", nohibernate_setup);