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