xref: /linux/kernel/power/hibernate.c (revision 02824a5fd11f99b4637668926a59aab3698b46a9)
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 static char hibernate_compressor[CRYPTO_MAX_ALG_NAME] = CONFIG_HIBERNATION_DEF_COMP;
51 
52 /*
53  * Compression/decompression algorithm to be used while saving/loading
54  * image to/from disk. This would later be used in 'kernel/power/swap.c'
55  * to allocate comp streams.
56  */
57 char hib_comp_algo[CRYPTO_MAX_ALG_NAME];
58 
59 enum {
60 	HIBERNATION_INVALID,
61 	HIBERNATION_PLATFORM,
62 	HIBERNATION_SHUTDOWN,
63 	HIBERNATION_REBOOT,
64 #ifdef CONFIG_SUSPEND
65 	HIBERNATION_SUSPEND,
66 #endif
67 	HIBERNATION_TEST_RESUME,
68 	/* keep last */
69 	__HIBERNATION_AFTER_LAST
70 };
71 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
72 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
73 
74 static int hibernation_mode = HIBERNATION_SHUTDOWN;
75 
76 bool freezer_test_done;
77 
78 static const struct platform_hibernation_ops *hibernation_ops;
79 
80 static atomic_t hibernate_atomic = ATOMIC_INIT(1);
81 
hibernate_acquire(void)82 bool hibernate_acquire(void)
83 {
84 	return atomic_add_unless(&hibernate_atomic, -1, 0);
85 }
86 
hibernate_release(void)87 void hibernate_release(void)
88 {
89 	atomic_inc(&hibernate_atomic);
90 }
91 
hibernation_available(void)92 bool hibernation_available(void)
93 {
94 	return nohibernate == 0 &&
95 		!security_locked_down(LOCKDOWN_HIBERNATION) &&
96 		!secretmem_active() && !cxl_mem_active();
97 }
98 
99 /**
100  * hibernation_set_ops - Set the global hibernate operations.
101  * @ops: Hibernation operations to use in subsequent hibernation transitions.
102  */
hibernation_set_ops(const struct platform_hibernation_ops * ops)103 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
104 {
105 	unsigned int sleep_flags;
106 
107 	if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
108 	    && ops->prepare && ops->finish && ops->enter && ops->pre_restore
109 	    && ops->restore_cleanup && ops->leave)) {
110 		WARN_ON(1);
111 		return;
112 	}
113 
114 	sleep_flags = lock_system_sleep();
115 
116 	hibernation_ops = ops;
117 	if (ops)
118 		hibernation_mode = HIBERNATION_PLATFORM;
119 	else if (hibernation_mode == HIBERNATION_PLATFORM)
120 		hibernation_mode = HIBERNATION_SHUTDOWN;
121 
122 	unlock_system_sleep(sleep_flags);
123 }
124 EXPORT_SYMBOL_GPL(hibernation_set_ops);
125 
126 static bool entering_platform_hibernation;
127 
system_entering_hibernation(void)128 bool system_entering_hibernation(void)
129 {
130 	return entering_platform_hibernation;
131 }
132 EXPORT_SYMBOL(system_entering_hibernation);
133 
134 #ifdef CONFIG_PM_DEBUG
hibernation_debug_sleep(void)135 static void hibernation_debug_sleep(void)
136 {
137 	pr_info("debug: Waiting for 5 seconds.\n");
138 	mdelay(5000);
139 }
140 
hibernation_test(int level)141 static int hibernation_test(int level)
142 {
143 	if (pm_test_level == level) {
144 		hibernation_debug_sleep();
145 		return 1;
146 	}
147 	return 0;
148 }
149 #else /* !CONFIG_PM_DEBUG */
hibernation_test(int level)150 static int hibernation_test(int level) { return 0; }
151 #endif /* !CONFIG_PM_DEBUG */
152 
153 /**
154  * platform_begin - Call platform to start hibernation.
155  * @platform_mode: Whether or not to use the platform driver.
156  */
platform_begin(int platform_mode)157 static int platform_begin(int platform_mode)
158 {
159 	return (platform_mode && hibernation_ops) ?
160 		hibernation_ops->begin(PMSG_FREEZE) : 0;
161 }
162 
163 /**
164  * platform_end - Call platform to finish transition to the working state.
165  * @platform_mode: Whether or not to use the platform driver.
166  */
platform_end(int platform_mode)167 static void platform_end(int platform_mode)
168 {
169 	if (platform_mode && hibernation_ops)
170 		hibernation_ops->end();
171 }
172 
173 /**
174  * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
175  * @platform_mode: Whether or not to use the platform driver.
176  *
177  * Use the platform driver to prepare the system for creating a hibernate image,
178  * if so configured, and return an error code if that fails.
179  */
180 
platform_pre_snapshot(int platform_mode)181 static int platform_pre_snapshot(int platform_mode)
182 {
183 	return (platform_mode && hibernation_ops) ?
184 		hibernation_ops->pre_snapshot() : 0;
185 }
186 
187 /**
188  * platform_leave - Call platform to prepare a transition to the working state.
189  * @platform_mode: Whether or not to use the platform driver.
190  *
191  * Use the platform driver prepare to prepare the machine for switching to the
192  * normal mode of operation.
193  *
194  * This routine is called on one CPU with interrupts disabled.
195  */
platform_leave(int platform_mode)196 static void platform_leave(int platform_mode)
197 {
198 	if (platform_mode && hibernation_ops)
199 		hibernation_ops->leave();
200 }
201 
202 /**
203  * platform_finish - Call platform to switch the system to the working state.
204  * @platform_mode: Whether or not to use the platform driver.
205  *
206  * Use the platform driver to switch the machine to the normal mode of
207  * operation.
208  *
209  * This routine must be called after platform_prepare().
210  */
platform_finish(int platform_mode)211 static void platform_finish(int platform_mode)
212 {
213 	if (platform_mode && hibernation_ops)
214 		hibernation_ops->finish();
215 }
216 
217 /**
218  * platform_pre_restore - Prepare for hibernate image restoration.
219  * @platform_mode: Whether or not to use the platform driver.
220  *
221  * Use the platform driver to prepare the system for resume from a hibernation
222  * image.
223  *
224  * If the restore fails after this function has been called,
225  * platform_restore_cleanup() must be called.
226  */
platform_pre_restore(int platform_mode)227 static int platform_pre_restore(int platform_mode)
228 {
229 	return (platform_mode && hibernation_ops) ?
230 		hibernation_ops->pre_restore() : 0;
231 }
232 
233 /**
234  * platform_restore_cleanup - Switch to the working state after failing restore.
235  * @platform_mode: Whether or not to use the platform driver.
236  *
237  * Use the platform driver to switch the system to the normal mode of operation
238  * after a failing restore.
239  *
240  * If platform_pre_restore() has been called before the failing restore, this
241  * function must be called too, regardless of the result of
242  * platform_pre_restore().
243  */
platform_restore_cleanup(int platform_mode)244 static void platform_restore_cleanup(int platform_mode)
245 {
246 	if (platform_mode && hibernation_ops)
247 		hibernation_ops->restore_cleanup();
248 }
249 
250 /**
251  * platform_recover - Recover from a failure to suspend devices.
252  * @platform_mode: Whether or not to use the platform driver.
253  */
platform_recover(int platform_mode)254 static void platform_recover(int platform_mode)
255 {
256 	if (platform_mode && hibernation_ops && hibernation_ops->recover)
257 		hibernation_ops->recover();
258 }
259 
260 /**
261  * swsusp_show_speed - Print time elapsed between two events during hibernation.
262  * @start: Starting event.
263  * @stop: Final event.
264  * @nr_pages: Number of memory pages processed between @start and @stop.
265  * @msg: Additional diagnostic message to print.
266  */
swsusp_show_speed(ktime_t start,ktime_t stop,unsigned nr_pages,char * msg)267 void swsusp_show_speed(ktime_t start, ktime_t stop,
268 		      unsigned nr_pages, char *msg)
269 {
270 	ktime_t diff;
271 	u64 elapsed_centisecs64;
272 	unsigned int centisecs;
273 	unsigned int k;
274 	unsigned int kps;
275 
276 	diff = ktime_sub(stop, start);
277 	elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
278 	centisecs = elapsed_centisecs64;
279 	if (centisecs == 0)
280 		centisecs = 1;	/* avoid div-by-zero */
281 	k = nr_pages * (PAGE_SIZE / 1024);
282 	kps = (k * 100) / centisecs;
283 	pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
284 		msg, k, centisecs / 100, centisecs % 100, kps / 1000,
285 		(kps % 1000) / 10);
286 }
287 
arch_resume_nosmt(void)288 __weak int arch_resume_nosmt(void)
289 {
290 	return 0;
291 }
292 
293 /**
294  * create_image - Create a hibernation image.
295  * @platform_mode: Whether or not to use the platform driver.
296  *
297  * Execute device drivers' "late" and "noirq" freeze callbacks, create a
298  * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
299  *
300  * Control reappears in this routine after the subsequent restore.
301  */
create_image(int platform_mode)302 static int create_image(int platform_mode)
303 {
304 	int error;
305 
306 	error = dpm_suspend_end(PMSG_FREEZE);
307 	if (error) {
308 		pr_err("Some devices failed to power down, aborting\n");
309 		return error;
310 	}
311 
312 	error = platform_pre_snapshot(platform_mode);
313 	if (error || hibernation_test(TEST_PLATFORM))
314 		goto Platform_finish;
315 
316 	error = pm_sleep_disable_secondary_cpus();
317 	if (error || hibernation_test(TEST_CPUS))
318 		goto Enable_cpus;
319 
320 	local_irq_disable();
321 
322 	system_state = SYSTEM_SUSPEND;
323 
324 	error = syscore_suspend();
325 	if (error) {
326 		pr_err("Some system devices failed to power down, aborting\n");
327 		goto Enable_irqs;
328 	}
329 
330 	if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
331 		goto Power_up;
332 
333 	in_suspend = 1;
334 	save_processor_state();
335 	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
336 	error = swsusp_arch_suspend();
337 	/* Restore control flow magically appears here */
338 	restore_processor_state();
339 	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
340 	if (error)
341 		pr_err("Error %d creating image\n", error);
342 
343 	if (!in_suspend) {
344 		events_check_enabled = false;
345 		clear_or_poison_free_pages();
346 	}
347 
348 	platform_leave(platform_mode);
349 
350  Power_up:
351 	syscore_resume();
352 
353  Enable_irqs:
354 	system_state = SYSTEM_RUNNING;
355 	local_irq_enable();
356 
357  Enable_cpus:
358 	pm_sleep_enable_secondary_cpus();
359 
360 	/* Allow architectures to do nosmt-specific post-resume dances */
361 	if (!in_suspend)
362 		error = arch_resume_nosmt();
363 
364  Platform_finish:
365 	platform_finish(platform_mode);
366 
367 	dpm_resume_start(in_suspend ?
368 		(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
369 
370 	return error;
371 }
372 
373 /**
374  * hibernation_snapshot - Quiesce devices and create a hibernation image.
375  * @platform_mode: If set, use platform driver to prepare for the transition.
376  *
377  * This routine must be called with system_transition_mutex held.
378  */
hibernation_snapshot(int platform_mode)379 int hibernation_snapshot(int platform_mode)
380 {
381 	pm_message_t msg;
382 	int error;
383 
384 	pm_suspend_clear_flags();
385 	error = platform_begin(platform_mode);
386 	if (error)
387 		goto Close;
388 
389 	/* Preallocate image memory before shutting down devices. */
390 	error = hibernate_preallocate_memory();
391 	if (error)
392 		goto Close;
393 
394 	error = freeze_kernel_threads();
395 	if (error)
396 		goto Cleanup;
397 
398 	if (hibernation_test(TEST_FREEZER)) {
399 
400 		/*
401 		 * Indicate to the caller that we are returning due to a
402 		 * successful freezer test.
403 		 */
404 		freezer_test_done = true;
405 		goto Thaw;
406 	}
407 
408 	error = dpm_prepare(PMSG_FREEZE);
409 	if (error) {
410 		dpm_complete(PMSG_RECOVER);
411 		goto Thaw;
412 	}
413 
414 	suspend_console();
415 	pm_restrict_gfp_mask();
416 
417 	error = dpm_suspend(PMSG_FREEZE);
418 
419 	if (error || hibernation_test(TEST_DEVICES))
420 		platform_recover(platform_mode);
421 	else
422 		error = create_image(platform_mode);
423 
424 	/*
425 	 * In the case that we call create_image() above, the control
426 	 * returns here (1) after the image has been created or the
427 	 * image creation has failed and (2) after a successful restore.
428 	 */
429 
430 	/* We may need to release the preallocated image pages here. */
431 	if (error || !in_suspend)
432 		swsusp_free();
433 
434 	msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
435 	dpm_resume(msg);
436 
437 	if (error || !in_suspend)
438 		pm_restore_gfp_mask();
439 
440 	resume_console();
441 	dpm_complete(msg);
442 
443  Close:
444 	platform_end(platform_mode);
445 	return error;
446 
447  Thaw:
448 	thaw_kernel_threads();
449  Cleanup:
450 	swsusp_free();
451 	goto Close;
452 }
453 
hibernate_resume_nonboot_cpu_disable(void)454 int __weak hibernate_resume_nonboot_cpu_disable(void)
455 {
456 	return suspend_disable_secondary_cpus();
457 }
458 
459 /**
460  * resume_target_kernel - Restore system state from a hibernation image.
461  * @platform_mode: Whether or not to use the platform driver.
462  *
463  * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
464  * contents of highmem that have not been restored yet from the image and run
465  * the low-level code that will restore the remaining contents of memory and
466  * switch to the just restored target kernel.
467  */
resume_target_kernel(bool platform_mode)468 static int resume_target_kernel(bool platform_mode)
469 {
470 	int error;
471 
472 	error = dpm_suspend_end(PMSG_QUIESCE);
473 	if (error) {
474 		pr_err("Some devices failed to power down, aborting resume\n");
475 		return error;
476 	}
477 
478 	error = platform_pre_restore(platform_mode);
479 	if (error)
480 		goto Cleanup;
481 
482 	cpuidle_pause();
483 
484 	error = hibernate_resume_nonboot_cpu_disable();
485 	if (error)
486 		goto Enable_cpus;
487 
488 	local_irq_disable();
489 	system_state = SYSTEM_SUSPEND;
490 
491 	error = syscore_suspend();
492 	if (error)
493 		goto Enable_irqs;
494 
495 	save_processor_state();
496 	error = restore_highmem();
497 	if (!error) {
498 		error = swsusp_arch_resume();
499 		/*
500 		 * The code below is only ever reached in case of a failure.
501 		 * Otherwise, execution continues at the place where
502 		 * swsusp_arch_suspend() was called.
503 		 */
504 		BUG_ON(!error);
505 		/*
506 		 * This call to restore_highmem() reverts the changes made by
507 		 * the previous one.
508 		 */
509 		restore_highmem();
510 	}
511 	/*
512 	 * The only reason why swsusp_arch_resume() can fail is memory being
513 	 * very tight, so we have to free it as soon as we can to avoid
514 	 * subsequent failures.
515 	 */
516 	swsusp_free();
517 	restore_processor_state();
518 	touch_softlockup_watchdog();
519 
520 	syscore_resume();
521 
522  Enable_irqs:
523 	system_state = SYSTEM_RUNNING;
524 	local_irq_enable();
525 
526  Enable_cpus:
527 	pm_sleep_enable_secondary_cpus();
528 
529  Cleanup:
530 	platform_restore_cleanup(platform_mode);
531 
532 	dpm_resume_start(PMSG_RECOVER);
533 
534 	return error;
535 }
536 
537 /**
538  * hibernation_restore - Quiesce devices and restore from a hibernation image.
539  * @platform_mode: If set, use platform driver to prepare for the transition.
540  *
541  * This routine must be called with system_transition_mutex held.  If it is
542  * successful, control reappears in the restored target kernel in
543  * hibernation_snapshot().
544  */
hibernation_restore(int platform_mode)545 int hibernation_restore(int platform_mode)
546 {
547 	int error;
548 
549 	pm_prepare_console();
550 	suspend_console();
551 	pm_restrict_gfp_mask();
552 	error = dpm_suspend_start(PMSG_QUIESCE);
553 	if (!error) {
554 		error = resume_target_kernel(platform_mode);
555 		/*
556 		 * The above should either succeed and jump to the new kernel,
557 		 * or return with an error. Otherwise things are just
558 		 * undefined, so let's be paranoid.
559 		 */
560 		BUG_ON(!error);
561 	}
562 	dpm_resume_end(PMSG_RECOVER);
563 	pm_restore_gfp_mask();
564 	resume_console();
565 	pm_restore_console();
566 	return error;
567 }
568 
569 /**
570  * hibernation_platform_enter - Power off the system using the platform driver.
571  */
hibernation_platform_enter(void)572 int hibernation_platform_enter(void)
573 {
574 	int error;
575 
576 	if (!hibernation_ops)
577 		return -ENOSYS;
578 
579 	/*
580 	 * We have cancelled the power transition by running
581 	 * hibernation_ops->finish() before saving the image, so we should let
582 	 * the firmware know that we're going to enter the sleep state after all
583 	 */
584 	error = hibernation_ops->begin(PMSG_HIBERNATE);
585 	if (error)
586 		goto Close;
587 
588 	entering_platform_hibernation = true;
589 	suspend_console();
590 	error = dpm_suspend_start(PMSG_HIBERNATE);
591 	if (error) {
592 		if (hibernation_ops->recover)
593 			hibernation_ops->recover();
594 		goto Resume_devices;
595 	}
596 
597 	error = dpm_suspend_end(PMSG_HIBERNATE);
598 	if (error)
599 		goto Resume_devices;
600 
601 	error = hibernation_ops->prepare();
602 	if (error)
603 		goto Platform_finish;
604 
605 	error = pm_sleep_disable_secondary_cpus();
606 	if (error)
607 		goto Enable_cpus;
608 
609 	local_irq_disable();
610 	system_state = SYSTEM_SUSPEND;
611 	syscore_suspend();
612 	if (pm_wakeup_pending()) {
613 		error = -EAGAIN;
614 		goto Power_up;
615 	}
616 
617 	hibernation_ops->enter();
618 	/* We should never get here */
619 	while (1);
620 
621  Power_up:
622 	syscore_resume();
623 	system_state = SYSTEM_RUNNING;
624 	local_irq_enable();
625 
626  Enable_cpus:
627 	pm_sleep_enable_secondary_cpus();
628 
629  Platform_finish:
630 	hibernation_ops->finish();
631 
632 	dpm_resume_start(PMSG_RESTORE);
633 
634  Resume_devices:
635 	entering_platform_hibernation = false;
636 	dpm_resume_end(PMSG_RESTORE);
637 	resume_console();
638 
639  Close:
640 	hibernation_ops->end();
641 
642 	return error;
643 }
644 
645 /**
646  * power_down - Shut the machine down for hibernation.
647  *
648  * Use the platform driver, if configured, to put the system into the sleep
649  * state corresponding to hibernation, or try to power it off or reboot,
650  * depending on the value of hibernation_mode.
651  */
power_down(void)652 static void power_down(void)
653 {
654 	int error;
655 
656 #ifdef CONFIG_SUSPEND
657 	if (hibernation_mode == HIBERNATION_SUSPEND) {
658 		error = suspend_devices_and_enter(mem_sleep_current);
659 		if (error) {
660 			hibernation_mode = hibernation_ops ?
661 						HIBERNATION_PLATFORM :
662 						HIBERNATION_SHUTDOWN;
663 		} else {
664 			/* Restore swap signature. */
665 			error = swsusp_unmark();
666 			if (error)
667 				pr_err("Swap will be unusable! Try swapon -a.\n");
668 
669 			return;
670 		}
671 	}
672 #endif
673 
674 	switch (hibernation_mode) {
675 	case HIBERNATION_REBOOT:
676 		kernel_restart(NULL);
677 		break;
678 	case HIBERNATION_PLATFORM:
679 		error = hibernation_platform_enter();
680 		if (error == -EAGAIN || error == -EBUSY) {
681 			swsusp_unmark();
682 			events_check_enabled = false;
683 			pr_info("Wakeup event detected during hibernation, rolling back.\n");
684 			return;
685 		}
686 		fallthrough;
687 	case HIBERNATION_SHUTDOWN:
688 		if (kernel_can_power_off())
689 			kernel_power_off();
690 		break;
691 	}
692 	kernel_halt();
693 	/*
694 	 * Valid image is on the disk, if we continue we risk serious data
695 	 * corruption after resume.
696 	 */
697 	pr_crit("Power down manually\n");
698 	while (1)
699 		cpu_relax();
700 }
701 
load_image_and_restore(void)702 static int load_image_and_restore(void)
703 {
704 	int error;
705 	unsigned int flags;
706 
707 	pm_pr_dbg("Loading hibernation image.\n");
708 
709 	lock_device_hotplug();
710 	error = create_basic_memory_bitmaps();
711 	if (error) {
712 		swsusp_close();
713 		goto Unlock;
714 	}
715 
716 	error = swsusp_read(&flags);
717 	swsusp_close();
718 	if (!error)
719 		error = hibernation_restore(flags & SF_PLATFORM_MODE);
720 
721 	pr_err("Failed to load image, recovering.\n");
722 	swsusp_free();
723 	free_basic_memory_bitmaps();
724  Unlock:
725 	unlock_device_hotplug();
726 
727 	return error;
728 }
729 
730 #define COMPRESSION_ALGO_LZO "lzo"
731 #define COMPRESSION_ALGO_LZ4 "lz4"
732 
733 /**
734  * hibernate - Carry out system hibernation, including saving the image.
735  */
hibernate(void)736 int hibernate(void)
737 {
738 	bool snapshot_test = false;
739 	unsigned int sleep_flags;
740 	int error;
741 
742 	if (!hibernation_available()) {
743 		pm_pr_dbg("Hibernation not available.\n");
744 		return -EPERM;
745 	}
746 
747 	/*
748 	 * Query for the compression algorithm support if compression is enabled.
749 	 */
750 	if (!nocompress) {
751 		strscpy(hib_comp_algo, hibernate_compressor, sizeof(hib_comp_algo));
752 		if (crypto_has_comp(hib_comp_algo, 0, 0) != 1) {
753 			pr_err("%s compression is not available\n", hib_comp_algo);
754 			return -EOPNOTSUPP;
755 		}
756 	}
757 
758 	sleep_flags = lock_system_sleep();
759 	/* The snapshot device should not be opened while we're running */
760 	if (!hibernate_acquire()) {
761 		error = -EBUSY;
762 		goto Unlock;
763 	}
764 
765 	pr_info("hibernation entry\n");
766 	pm_prepare_console();
767 	error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
768 	if (error)
769 		goto Restore;
770 
771 	ksys_sync_helper();
772 
773 	error = freeze_processes();
774 	if (error)
775 		goto Exit;
776 
777 	lock_device_hotplug();
778 	/* Allocate memory management structures */
779 	error = create_basic_memory_bitmaps();
780 	if (error)
781 		goto Thaw;
782 
783 	error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
784 	if (error || freezer_test_done)
785 		goto Free_bitmaps;
786 
787 	if (in_suspend) {
788 		unsigned int flags = 0;
789 
790 		if (hibernation_mode == HIBERNATION_PLATFORM)
791 			flags |= SF_PLATFORM_MODE;
792 		if (nocompress) {
793 			flags |= SF_NOCOMPRESS_MODE;
794 		} else {
795 		        flags |= SF_CRC32_MODE;
796 
797 			/*
798 			 * By default, LZO compression is enabled. Use SF_COMPRESSION_ALG_LZ4
799 			 * to override this behaviour and use LZ4.
800 			 *
801 			 * Refer kernel/power/power.h for more details
802 			 */
803 
804 			if (!strcmp(hib_comp_algo, COMPRESSION_ALGO_LZ4))
805 				flags |= SF_COMPRESSION_ALG_LZ4;
806 			else
807 				flags |= SF_COMPRESSION_ALG_LZO;
808 		}
809 
810 		pm_pr_dbg("Writing hibernation image.\n");
811 		error = swsusp_write(flags);
812 		swsusp_free();
813 		if (!error) {
814 			if (hibernation_mode == HIBERNATION_TEST_RESUME)
815 				snapshot_test = true;
816 			else
817 				power_down();
818 		}
819 		in_suspend = 0;
820 		pm_restore_gfp_mask();
821 	} else {
822 		pm_pr_dbg("Hibernation image restored successfully.\n");
823 	}
824 
825  Free_bitmaps:
826 	free_basic_memory_bitmaps();
827  Thaw:
828 	unlock_device_hotplug();
829 	if (snapshot_test) {
830 		pm_pr_dbg("Checking hibernation image\n");
831 		error = swsusp_check(false);
832 		if (!error)
833 			error = load_image_and_restore();
834 	}
835 	thaw_processes();
836 
837 	/* Don't bother checking whether freezer_test_done is true */
838 	freezer_test_done = false;
839  Exit:
840 	pm_notifier_call_chain(PM_POST_HIBERNATION);
841  Restore:
842 	pm_restore_console();
843 	hibernate_release();
844  Unlock:
845 	unlock_system_sleep(sleep_flags);
846 	pr_info("hibernation exit\n");
847 
848 	return error;
849 }
850 
851 /**
852  * hibernate_quiet_exec - Execute a function with all devices frozen.
853  * @func: Function to execute.
854  * @data: Data pointer to pass to @func.
855  *
856  * Return the @func return value or an error code if it cannot be executed.
857  */
hibernate_quiet_exec(int (* func)(void * data),void * data)858 int hibernate_quiet_exec(int (*func)(void *data), void *data)
859 {
860 	unsigned int sleep_flags;
861 	int error;
862 
863 	sleep_flags = lock_system_sleep();
864 
865 	if (!hibernate_acquire()) {
866 		error = -EBUSY;
867 		goto unlock;
868 	}
869 
870 	pm_prepare_console();
871 
872 	error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
873 	if (error)
874 		goto restore;
875 
876 	error = freeze_processes();
877 	if (error)
878 		goto exit;
879 
880 	lock_device_hotplug();
881 
882 	pm_suspend_clear_flags();
883 
884 	error = platform_begin(true);
885 	if (error)
886 		goto thaw;
887 
888 	error = freeze_kernel_threads();
889 	if (error)
890 		goto thaw;
891 
892 	error = dpm_prepare(PMSG_FREEZE);
893 	if (error)
894 		goto dpm_complete;
895 
896 	suspend_console();
897 
898 	error = dpm_suspend(PMSG_FREEZE);
899 	if (error)
900 		goto dpm_resume;
901 
902 	error = dpm_suspend_end(PMSG_FREEZE);
903 	if (error)
904 		goto dpm_resume;
905 
906 	error = platform_pre_snapshot(true);
907 	if (error)
908 		goto skip;
909 
910 	error = func(data);
911 
912 skip:
913 	platform_finish(true);
914 
915 	dpm_resume_start(PMSG_THAW);
916 
917 dpm_resume:
918 	dpm_resume(PMSG_THAW);
919 
920 	resume_console();
921 
922 dpm_complete:
923 	dpm_complete(PMSG_THAW);
924 
925 	thaw_kernel_threads();
926 
927 thaw:
928 	platform_end(true);
929 
930 	unlock_device_hotplug();
931 
932 	thaw_processes();
933 
934 exit:
935 	pm_notifier_call_chain(PM_POST_HIBERNATION);
936 
937 restore:
938 	pm_restore_console();
939 
940 	hibernate_release();
941 
942 unlock:
943 	unlock_system_sleep(sleep_flags);
944 
945 	return error;
946 }
947 EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
948 
find_resume_device(void)949 static int __init find_resume_device(void)
950 {
951 	if (!strlen(resume_file))
952 		return -ENOENT;
953 
954 	pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
955 
956 	if (resume_delay) {
957 		pr_info("Waiting %dsec before reading resume device ...\n",
958 			resume_delay);
959 		ssleep(resume_delay);
960 	}
961 
962 	/* Check if the device is there */
963 	if (!early_lookup_bdev(resume_file, &swsusp_resume_device))
964 		return 0;
965 
966 	/*
967 	 * Some device discovery might still be in progress; we need to wait for
968 	 * this to finish.
969 	 */
970 	wait_for_device_probe();
971 	if (resume_wait) {
972 		while (early_lookup_bdev(resume_file, &swsusp_resume_device))
973 			msleep(10);
974 		async_synchronize_full();
975 	}
976 
977 	return early_lookup_bdev(resume_file, &swsusp_resume_device);
978 }
979 
software_resume(void)980 static int software_resume(void)
981 {
982 	int error;
983 
984 	pm_pr_dbg("Hibernation image partition %d:%d present\n",
985 		MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
986 
987 	pm_pr_dbg("Looking for hibernation image.\n");
988 
989 	mutex_lock(&system_transition_mutex);
990 	error = swsusp_check(true);
991 	if (error)
992 		goto Unlock;
993 
994 	/*
995 	 * Check if the hibernation image is compressed. If so, query for
996 	 * the algorithm support.
997 	 */
998 	if (!(swsusp_header_flags & SF_NOCOMPRESS_MODE)) {
999 		if (swsusp_header_flags & SF_COMPRESSION_ALG_LZ4)
1000 			strscpy(hib_comp_algo, COMPRESSION_ALGO_LZ4, sizeof(hib_comp_algo));
1001 		else
1002 			strscpy(hib_comp_algo, COMPRESSION_ALGO_LZO, sizeof(hib_comp_algo));
1003 		if (crypto_has_comp(hib_comp_algo, 0, 0) != 1) {
1004 			pr_err("%s compression is not available\n", hib_comp_algo);
1005 			error = -EOPNOTSUPP;
1006 			goto Unlock;
1007 		}
1008 	}
1009 
1010 	/* The snapshot device should not be opened while we're running */
1011 	if (!hibernate_acquire()) {
1012 		error = -EBUSY;
1013 		swsusp_close();
1014 		goto Unlock;
1015 	}
1016 
1017 	pr_info("resume from hibernation\n");
1018 	pm_prepare_console();
1019 	error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
1020 	if (error)
1021 		goto Restore;
1022 
1023 	pm_pr_dbg("Preparing processes for hibernation restore.\n");
1024 	error = freeze_processes();
1025 	if (error)
1026 		goto Close_Finish;
1027 
1028 	error = freeze_kernel_threads();
1029 	if (error) {
1030 		thaw_processes();
1031 		goto Close_Finish;
1032 	}
1033 
1034 	error = load_image_and_restore();
1035 	thaw_processes();
1036  Finish:
1037 	pm_notifier_call_chain(PM_POST_RESTORE);
1038  Restore:
1039 	pm_restore_console();
1040 	pr_info("resume failed (%d)\n", error);
1041 	hibernate_release();
1042 	/* For success case, the suspend path will release the lock */
1043  Unlock:
1044 	mutex_unlock(&system_transition_mutex);
1045 	pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
1046 	return error;
1047  Close_Finish:
1048 	swsusp_close();
1049 	goto Finish;
1050 }
1051 
1052 /**
1053  * software_resume_initcall - Resume from a saved hibernation image.
1054  *
1055  * This routine is called as a late initcall, when all devices have been
1056  * discovered and initialized already.
1057  *
1058  * The image reading code is called to see if there is a hibernation image
1059  * available for reading.  If that is the case, devices are quiesced and the
1060  * contents of memory is restored from the saved image.
1061  *
1062  * If this is successful, control reappears in the restored target kernel in
1063  * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
1064  * attempts to recover gracefully and make the kernel return to the normal mode
1065  * of operation.
1066  */
software_resume_initcall(void)1067 static int __init software_resume_initcall(void)
1068 {
1069 	/*
1070 	 * If the user said "noresume".. bail out early.
1071 	 */
1072 	if (noresume || !hibernation_available())
1073 		return 0;
1074 
1075 	if (!swsusp_resume_device) {
1076 		int error = find_resume_device();
1077 
1078 		if (error)
1079 			return error;
1080 	}
1081 
1082 	return software_resume();
1083 }
1084 late_initcall_sync(software_resume_initcall);
1085 
1086 
1087 static const char * const hibernation_modes[] = {
1088 	[HIBERNATION_PLATFORM]	= "platform",
1089 	[HIBERNATION_SHUTDOWN]	= "shutdown",
1090 	[HIBERNATION_REBOOT]	= "reboot",
1091 #ifdef CONFIG_SUSPEND
1092 	[HIBERNATION_SUSPEND]	= "suspend",
1093 #endif
1094 	[HIBERNATION_TEST_RESUME]	= "test_resume",
1095 };
1096 
1097 /*
1098  * /sys/power/disk - Control hibernation mode.
1099  *
1100  * Hibernation can be handled in several ways.  There are a few different ways
1101  * to put the system into the sleep state: using the platform driver (e.g. ACPI
1102  * or other hibernation_ops), powering it off or rebooting it (for testing
1103  * mostly).
1104  *
1105  * The sysfs file /sys/power/disk provides an interface for selecting the
1106  * hibernation mode to use.  Reading from this file causes the available modes
1107  * to be printed.  There are 3 modes that can be supported:
1108  *
1109  *	'platform'
1110  *	'shutdown'
1111  *	'reboot'
1112  *
1113  * If a platform hibernation driver is in use, 'platform' will be supported
1114  * and will be used by default.  Otherwise, 'shutdown' will be used by default.
1115  * The selected option (i.e. the one corresponding to the current value of
1116  * hibernation_mode) is enclosed by a square bracket.
1117  *
1118  * To select a given hibernation mode it is necessary to write the mode's
1119  * string representation (as returned by reading from /sys/power/disk) back
1120  * into /sys/power/disk.
1121  */
1122 
disk_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)1123 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1124 			 char *buf)
1125 {
1126 	ssize_t count = 0;
1127 	int i;
1128 
1129 	if (!hibernation_available())
1130 		return sysfs_emit(buf, "[disabled]\n");
1131 
1132 	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1133 		if (!hibernation_modes[i])
1134 			continue;
1135 		switch (i) {
1136 		case HIBERNATION_SHUTDOWN:
1137 		case HIBERNATION_REBOOT:
1138 #ifdef CONFIG_SUSPEND
1139 		case HIBERNATION_SUSPEND:
1140 #endif
1141 		case HIBERNATION_TEST_RESUME:
1142 			break;
1143 		case HIBERNATION_PLATFORM:
1144 			if (hibernation_ops)
1145 				break;
1146 			/* not a valid mode, continue with loop */
1147 			continue;
1148 		}
1149 		if (i == hibernation_mode)
1150 			count += sysfs_emit_at(buf, count, "[%s] ", hibernation_modes[i]);
1151 		else
1152 			count += sysfs_emit_at(buf, count, "%s ", hibernation_modes[i]);
1153 	}
1154 
1155 	/* Convert the last space to a newline if needed. */
1156 	if (count > 0)
1157 		buf[count - 1] = '\n';
1158 
1159 	return count;
1160 }
1161 
disk_store(struct kobject * kobj,struct kobj_attribute * attr,const char * buf,size_t n)1162 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1163 			  const char *buf, size_t n)
1164 {
1165 	int mode = HIBERNATION_INVALID;
1166 	unsigned int sleep_flags;
1167 	int error = 0;
1168 	int len;
1169 	char *p;
1170 	int i;
1171 
1172 	if (!hibernation_available())
1173 		return -EPERM;
1174 
1175 	p = memchr(buf, '\n', n);
1176 	len = p ? p - buf : n;
1177 
1178 	sleep_flags = lock_system_sleep();
1179 	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1180 		if (len == strlen(hibernation_modes[i])
1181 		    && !strncmp(buf, hibernation_modes[i], len)) {
1182 			mode = i;
1183 			break;
1184 		}
1185 	}
1186 	if (mode != HIBERNATION_INVALID) {
1187 		switch (mode) {
1188 		case HIBERNATION_SHUTDOWN:
1189 		case HIBERNATION_REBOOT:
1190 #ifdef CONFIG_SUSPEND
1191 		case HIBERNATION_SUSPEND:
1192 #endif
1193 		case HIBERNATION_TEST_RESUME:
1194 			hibernation_mode = mode;
1195 			break;
1196 		case HIBERNATION_PLATFORM:
1197 			if (hibernation_ops)
1198 				hibernation_mode = mode;
1199 			else
1200 				error = -EINVAL;
1201 		}
1202 	} else
1203 		error = -EINVAL;
1204 
1205 	if (!error)
1206 		pm_pr_dbg("Hibernation mode set to '%s'\n",
1207 			       hibernation_modes[mode]);
1208 	unlock_system_sleep(sleep_flags);
1209 	return error ? error : n;
1210 }
1211 
1212 power_attr(disk);
1213 
resume_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)1214 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1215 			   char *buf)
1216 {
1217 	return sysfs_emit(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1218 			  MINOR(swsusp_resume_device));
1219 }
1220 
resume_store(struct kobject * kobj,struct kobj_attribute * attr,const char * buf,size_t n)1221 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1222 			    const char *buf, size_t n)
1223 {
1224 	unsigned int sleep_flags;
1225 	int len = n;
1226 	char *name;
1227 	dev_t dev;
1228 	int error;
1229 
1230 	if (!hibernation_available())
1231 		return n;
1232 
1233 	if (len && buf[len-1] == '\n')
1234 		len--;
1235 	name = kstrndup(buf, len, GFP_KERNEL);
1236 	if (!name)
1237 		return -ENOMEM;
1238 
1239 	error = lookup_bdev(name, &dev);
1240 	if (error) {
1241 		unsigned maj, min, offset;
1242 		char *p, dummy;
1243 
1244 		error = 0;
1245 		if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 ||
1246 		    sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset,
1247 				&dummy) == 3) {
1248 			dev = MKDEV(maj, min);
1249 			if (maj != MAJOR(dev) || min != MINOR(dev))
1250 				error = -EINVAL;
1251 		} else {
1252 			dev = new_decode_dev(simple_strtoul(name, &p, 16));
1253 			if (*p)
1254 				error = -EINVAL;
1255 		}
1256 	}
1257 	kfree(name);
1258 	if (error)
1259 		return error;
1260 
1261 	sleep_flags = lock_system_sleep();
1262 	swsusp_resume_device = dev;
1263 	unlock_system_sleep(sleep_flags);
1264 
1265 	pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1266 		  swsusp_resume_device);
1267 	noresume = 0;
1268 	software_resume();
1269 	return n;
1270 }
1271 
1272 power_attr(resume);
1273 
resume_offset_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)1274 static ssize_t resume_offset_show(struct kobject *kobj,
1275 				  struct kobj_attribute *attr, char *buf)
1276 {
1277 	return sysfs_emit(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1278 }
1279 
resume_offset_store(struct kobject * kobj,struct kobj_attribute * attr,const char * buf,size_t n)1280 static ssize_t resume_offset_store(struct kobject *kobj,
1281 				   struct kobj_attribute *attr, const char *buf,
1282 				   size_t n)
1283 {
1284 	unsigned long long offset;
1285 	int rc;
1286 
1287 	rc = kstrtoull(buf, 0, &offset);
1288 	if (rc)
1289 		return rc;
1290 	swsusp_resume_block = offset;
1291 
1292 	return n;
1293 }
1294 
1295 power_attr(resume_offset);
1296 
image_size_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)1297 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1298 			       char *buf)
1299 {
1300 	return sysfs_emit(buf, "%lu\n", image_size);
1301 }
1302 
image_size_store(struct kobject * kobj,struct kobj_attribute * attr,const char * buf,size_t n)1303 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1304 				const char *buf, size_t n)
1305 {
1306 	unsigned long size;
1307 
1308 	if (sscanf(buf, "%lu", &size) == 1) {
1309 		image_size = size;
1310 		return n;
1311 	}
1312 
1313 	return -EINVAL;
1314 }
1315 
1316 power_attr(image_size);
1317 
reserved_size_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)1318 static ssize_t reserved_size_show(struct kobject *kobj,
1319 				  struct kobj_attribute *attr, char *buf)
1320 {
1321 	return sysfs_emit(buf, "%lu\n", reserved_size);
1322 }
1323 
reserved_size_store(struct kobject * kobj,struct kobj_attribute * attr,const char * buf,size_t n)1324 static ssize_t reserved_size_store(struct kobject *kobj,
1325 				   struct kobj_attribute *attr,
1326 				   const char *buf, size_t n)
1327 {
1328 	unsigned long size;
1329 
1330 	if (sscanf(buf, "%lu", &size) == 1) {
1331 		reserved_size = size;
1332 		return n;
1333 	}
1334 
1335 	return -EINVAL;
1336 }
1337 
1338 power_attr(reserved_size);
1339 
1340 static struct attribute *g[] = {
1341 	&disk_attr.attr,
1342 	&resume_offset_attr.attr,
1343 	&resume_attr.attr,
1344 	&image_size_attr.attr,
1345 	&reserved_size_attr.attr,
1346 	NULL,
1347 };
1348 
1349 
1350 static const struct attribute_group attr_group = {
1351 	.attrs = g,
1352 };
1353 
1354 
pm_disk_init(void)1355 static int __init pm_disk_init(void)
1356 {
1357 	return sysfs_create_group(power_kobj, &attr_group);
1358 }
1359 
1360 core_initcall(pm_disk_init);
1361 
1362 
resume_setup(char * str)1363 static int __init resume_setup(char *str)
1364 {
1365 	if (noresume)
1366 		return 1;
1367 
1368 	strscpy(resume_file, str);
1369 	return 1;
1370 }
1371 
resume_offset_setup(char * str)1372 static int __init resume_offset_setup(char *str)
1373 {
1374 	unsigned long long offset;
1375 
1376 	if (noresume)
1377 		return 1;
1378 
1379 	if (sscanf(str, "%llu", &offset) == 1)
1380 		swsusp_resume_block = offset;
1381 
1382 	return 1;
1383 }
1384 
hibernate_setup(char * str)1385 static int __init hibernate_setup(char *str)
1386 {
1387 	if (!strncmp(str, "noresume", 8)) {
1388 		noresume = 1;
1389 	} else if (!strncmp(str, "nocompress", 10)) {
1390 		nocompress = 1;
1391 	} else if (!strncmp(str, "no", 2)) {
1392 		noresume = 1;
1393 		nohibernate = 1;
1394 	} else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1395 		   && !strncmp(str, "protect_image", 13)) {
1396 		enable_restore_image_protection();
1397 	}
1398 	return 1;
1399 }
1400 
noresume_setup(char * str)1401 static int __init noresume_setup(char *str)
1402 {
1403 	noresume = 1;
1404 	return 1;
1405 }
1406 
resumewait_setup(char * str)1407 static int __init resumewait_setup(char *str)
1408 {
1409 	resume_wait = 1;
1410 	return 1;
1411 }
1412 
resumedelay_setup(char * str)1413 static int __init resumedelay_setup(char *str)
1414 {
1415 	int rc = kstrtouint(str, 0, &resume_delay);
1416 
1417 	if (rc)
1418 		pr_warn("resumedelay: bad option string '%s'\n", str);
1419 	return 1;
1420 }
1421 
nohibernate_setup(char * str)1422 static int __init nohibernate_setup(char *str)
1423 {
1424 	noresume = 1;
1425 	nohibernate = 1;
1426 	return 1;
1427 }
1428 
1429 static const char * const comp_alg_enabled[] = {
1430 #if IS_ENABLED(CONFIG_CRYPTO_LZO)
1431 	COMPRESSION_ALGO_LZO,
1432 #endif
1433 #if IS_ENABLED(CONFIG_CRYPTO_LZ4)
1434 	COMPRESSION_ALGO_LZ4,
1435 #endif
1436 };
1437 
hibernate_compressor_param_set(const char * compressor,const struct kernel_param * kp)1438 static int hibernate_compressor_param_set(const char *compressor,
1439 		const struct kernel_param *kp)
1440 {
1441 	unsigned int sleep_flags;
1442 	int index, ret;
1443 
1444 	sleep_flags = lock_system_sleep();
1445 
1446 	index = sysfs_match_string(comp_alg_enabled, compressor);
1447 	if (index >= 0) {
1448 		ret = param_set_copystring(comp_alg_enabled[index], kp);
1449 		if (!ret)
1450 			strscpy(hib_comp_algo, comp_alg_enabled[index],
1451 				sizeof(hib_comp_algo));
1452 	} else {
1453 		ret = index;
1454 	}
1455 
1456 	unlock_system_sleep(sleep_flags);
1457 
1458 	if (ret)
1459 		pr_debug("Cannot set specified compressor %s\n",
1460 			 compressor);
1461 
1462 	return ret;
1463 }
1464 
1465 static const struct kernel_param_ops hibernate_compressor_param_ops = {
1466 	.set    = hibernate_compressor_param_set,
1467 	.get    = param_get_string,
1468 };
1469 
1470 static struct kparam_string hibernate_compressor_param_string = {
1471 	.maxlen = sizeof(hibernate_compressor),
1472 	.string = hibernate_compressor,
1473 };
1474 
1475 module_param_cb(compressor, &hibernate_compressor_param_ops,
1476 		&hibernate_compressor_param_string, 0644);
1477 MODULE_PARM_DESC(compressor,
1478 		 "Compression algorithm to be used with hibernation");
1479 
1480 __setup("noresume", noresume_setup);
1481 __setup("resume_offset=", resume_offset_setup);
1482 __setup("resume=", resume_setup);
1483 __setup("hibernate=", hibernate_setup);
1484 __setup("resumewait", resumewait_setup);
1485 __setup("resumedelay=", resumedelay_setup);
1486 __setup("nohibernate", nohibernate_setup);
1487