2 * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 * Copyright (c) 2004 Pavel Machek <pavel@suse.cz>
7 * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
9 * This file is released under the GPLv2.
12 #include <linux/suspend.h>
13 #include <linux/syscalls.h>
14 #include <linux/reboot.h>
15 #include <linux/string.h>
16 #include <linux/device.h>
17 #include <linux/kmod.h>
18 #include <linux/delay.h>
20 #include <linux/mount.h>
22 #include <linux/console.h>
23 #include <linux/cpu.h>
24 #include <linux/freezer.h>
25 #include <scsi/scsi_scan.h>
26 #include <asm/suspend.h>
31 static int noresume = 0;
32 static char resume_file[256] = CONFIG_PM_STD_PARTITION;
33 dev_t swsusp_resume_device;
34 sector_t swsusp_resume_block;
44 __HIBERNATION_AFTER_LAST
46 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
47 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
49 static int hibernation_mode = HIBERNATION_SHUTDOWN;
51 static struct platform_hibernation_ops *hibernation_ops;
54 * hibernation_set_ops - set the global hibernate operations
55 * @ops: the hibernation operations to use in subsequent hibernation transitions
58 void hibernation_set_ops(struct platform_hibernation_ops *ops)
60 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
61 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
62 && ops->restore_cleanup)) {
66 mutex_lock(&pm_mutex);
67 hibernation_ops = ops;
69 hibernation_mode = HIBERNATION_PLATFORM;
70 else if (hibernation_mode == HIBERNATION_PLATFORM)
71 hibernation_mode = HIBERNATION_SHUTDOWN;
73 mutex_unlock(&pm_mutex);
76 static bool entering_platform_hibernation;
78 bool system_entering_hibernation(void)
80 return entering_platform_hibernation;
82 EXPORT_SYMBOL(system_entering_hibernation);
84 #ifdef CONFIG_PM_DEBUG
85 static void hibernation_debug_sleep(void)
87 printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
91 static int hibernation_testmode(int mode)
93 if (hibernation_mode == mode) {
94 hibernation_debug_sleep();
100 static int hibernation_test(int level)
102 if (pm_test_level == level) {
103 hibernation_debug_sleep();
108 #else /* !CONFIG_PM_DEBUG */
109 static int hibernation_testmode(int mode) { return 0; }
110 static int hibernation_test(int level) { return 0; }
111 #endif /* !CONFIG_PM_DEBUG */
114 * platform_begin - tell the platform driver that we're starting
118 static int platform_begin(int platform_mode)
120 return (platform_mode && hibernation_ops) ?
121 hibernation_ops->begin() : 0;
125 * platform_end - tell the platform driver that we've entered the
129 static void platform_end(int platform_mode)
131 if (platform_mode && hibernation_ops)
132 hibernation_ops->end();
136 * platform_pre_snapshot - prepare the machine for hibernation using the
137 * platform driver if so configured and return an error code if it fails
140 static int platform_pre_snapshot(int platform_mode)
142 return (platform_mode && hibernation_ops) ?
143 hibernation_ops->pre_snapshot() : 0;
147 * platform_leave - prepare the machine for switching to the normal mode
148 * of operation using the platform driver (called with interrupts disabled)
151 static void platform_leave(int platform_mode)
153 if (platform_mode && hibernation_ops)
154 hibernation_ops->leave();
158 * platform_finish - switch the machine to the normal mode of operation
159 * using the platform driver (must be called after platform_prepare())
162 static void platform_finish(int platform_mode)
164 if (platform_mode && hibernation_ops)
165 hibernation_ops->finish();
169 * platform_pre_restore - prepare the platform for the restoration from a
170 * hibernation image. If the restore fails after this function has been
171 * called, platform_restore_cleanup() must be called.
174 static int platform_pre_restore(int platform_mode)
176 return (platform_mode && hibernation_ops) ?
177 hibernation_ops->pre_restore() : 0;
181 * platform_restore_cleanup - switch the platform to the normal mode of
182 * operation after a failing restore. If platform_pre_restore() has been
183 * called before the failing restore, this function must be called too,
184 * regardless of the result of platform_pre_restore().
187 static void platform_restore_cleanup(int platform_mode)
189 if (platform_mode && hibernation_ops)
190 hibernation_ops->restore_cleanup();
194 * platform_recover - recover the platform from a failure to suspend
198 static void platform_recover(int platform_mode)
200 if (platform_mode && hibernation_ops && hibernation_ops->recover)
201 hibernation_ops->recover();
205 * create_image - freeze devices that need to be frozen with interrupts
206 * off, create the hibernation image and thaw those devices. Control
207 * reappears in this routine after a restore.
210 static int create_image(int platform_mode)
214 error = arch_prepare_suspend();
218 /* At this point, dpm_suspend_start() has been called, but *not*
219 * dpm_suspend_noirq(). We *must* call dpm_suspend_noirq() now.
220 * Otherwise, drivers for some devices (e.g. interrupt controllers)
221 * become desynchronized with the actual state of the hardware
222 * at resume time, and evil weirdness ensues.
224 error = dpm_suspend_noirq(PMSG_FREEZE);
226 printk(KERN_ERR "PM: Some devices failed to power down, "
227 "aborting hibernation\n");
231 error = platform_pre_snapshot(platform_mode);
232 if (error || hibernation_test(TEST_PLATFORM))
233 goto Platform_finish;
235 error = disable_nonboot_cpus();
236 if (error || hibernation_test(TEST_CPUS)
237 || hibernation_testmode(HIBERNATION_TEST))
242 error = sysdev_suspend(PMSG_FREEZE);
244 printk(KERN_ERR "PM: Some system devices failed to power down, "
245 "aborting hibernation\n");
249 if (hibernation_test(TEST_CORE))
253 save_processor_state();
254 error = swsusp_arch_suspend();
256 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
258 /* Restore control flow magically appears here */
259 restore_processor_state();
261 platform_leave(platform_mode);
265 /* NOTE: dpm_resume_noirq() is just a resume() for devices
266 * that suspended with irqs off ... no overall powerup.
273 enable_nonboot_cpus();
276 platform_finish(platform_mode);
278 dpm_resume_noirq(in_suspend ?
279 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
285 * hibernation_snapshot - quiesce devices and create the hibernation
287 * @platform_mode - if set, use the platform driver, if available, to
288 * prepare the platform firmware for the power transition.
290 * Must be called with pm_mutex held
293 int hibernation_snapshot(int platform_mode)
297 error = platform_begin(platform_mode);
301 /* Preallocate image memory before shutting down devices. */
302 error = hibernate_preallocate_memory();
307 error = dpm_suspend_start(PMSG_FREEZE);
309 goto Recover_platform;
311 if (hibernation_test(TEST_DEVICES))
312 goto Recover_platform;
314 error = create_image(platform_mode);
315 /* Control returns here after successful restore */
318 /* We may need to release the preallocated image pages here. */
319 if (error || !in_suspend)
322 dpm_resume_end(in_suspend ?
323 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
326 platform_end(platform_mode);
330 platform_recover(platform_mode);
335 * resume_target_kernel - prepare devices that need to be suspended with
336 * interrupts off, restore the contents of highmem that have not been
337 * restored yet from the image and run the low level code that will restore
338 * the remaining contents of memory and switch to the just restored target
342 static int resume_target_kernel(bool platform_mode)
346 error = dpm_suspend_noirq(PMSG_QUIESCE);
348 printk(KERN_ERR "PM: Some devices failed to power down, "
349 "aborting resume\n");
353 error = platform_pre_restore(platform_mode);
357 error = disable_nonboot_cpus();
363 error = sysdev_suspend(PMSG_QUIESCE);
367 /* We'll ignore saved state, but this gets preempt count (etc) right */
368 save_processor_state();
369 error = restore_highmem();
371 error = swsusp_arch_resume();
373 * The code below is only ever reached in case of a failure.
374 * Otherwise execution continues at place where
375 * swsusp_arch_suspend() was called
378 /* This call to restore_highmem() undos the previous one */
382 * The only reason why swsusp_arch_resume() can fail is memory being
383 * very tight, so we have to free it as soon as we can to avoid
384 * subsequent failures
387 restore_processor_state();
388 touch_softlockup_watchdog();
396 enable_nonboot_cpus();
399 platform_restore_cleanup(platform_mode);
401 dpm_resume_noirq(PMSG_RECOVER);
407 * hibernation_restore - quiesce devices and restore the hibernation
408 * snapshot image. If successful, control returns in hibernation_snaphot()
409 * @platform_mode - if set, use the platform driver, if available, to
410 * prepare the platform firmware for the transition.
412 * Must be called with pm_mutex held
415 int hibernation_restore(int platform_mode)
419 pm_prepare_console();
421 error = dpm_suspend_start(PMSG_QUIESCE);
423 error = resume_target_kernel(platform_mode);
424 dpm_resume_end(PMSG_RECOVER);
427 pm_restore_console();
432 * hibernation_platform_enter - enter the hibernation state using the
433 * platform driver (if available)
436 int hibernation_platform_enter(void)
440 if (!hibernation_ops)
444 * We have cancelled the power transition by running
445 * hibernation_ops->finish() before saving the image, so we should let
446 * the firmware know that we're going to enter the sleep state after all
448 error = hibernation_ops->begin();
452 entering_platform_hibernation = true;
454 error = dpm_suspend_start(PMSG_HIBERNATE);
456 if (hibernation_ops->recover)
457 hibernation_ops->recover();
461 error = dpm_suspend_noirq(PMSG_HIBERNATE);
465 error = hibernation_ops->prepare();
467 goto Platform_finish;
469 error = disable_nonboot_cpus();
471 goto Platform_finish;
474 sysdev_suspend(PMSG_HIBERNATE);
475 hibernation_ops->enter();
476 /* We should never get here */
480 * We don't need to reenable the nonboot CPUs or resume consoles, since
481 * the system is going to be halted anyway.
484 hibernation_ops->finish();
486 dpm_suspend_noirq(PMSG_RESTORE);
489 entering_platform_hibernation = false;
490 dpm_resume_end(PMSG_RESTORE);
494 hibernation_ops->end();
500 * power_down - Shut the machine down for hibernation.
502 * Use the platform driver, if configured so; otherwise try
503 * to power off or reboot.
506 static void power_down(void)
508 switch (hibernation_mode) {
509 case HIBERNATION_TEST:
510 case HIBERNATION_TESTPROC:
512 case HIBERNATION_REBOOT:
513 kernel_restart(NULL);
515 case HIBERNATION_PLATFORM:
516 hibernation_platform_enter();
517 case HIBERNATION_SHUTDOWN:
523 * Valid image is on the disk, if we continue we risk serious data
524 * corruption after resume.
526 printk(KERN_CRIT "PM: Please power down manually\n");
530 static int prepare_processes(void)
534 if (freeze_processes()) {
542 * hibernate - The granpappy of the built-in hibernation management
549 mutex_lock(&pm_mutex);
550 /* The snapshot device should not be opened while we're running */
551 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
556 pm_prepare_console();
557 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
561 error = usermodehelper_disable();
565 /* Allocate memory management structures */
566 error = create_basic_memory_bitmaps();
570 printk(KERN_INFO "PM: Syncing filesystems ... ");
574 error = prepare_processes();
578 if (hibernation_test(TEST_FREEZER))
581 if (hibernation_testmode(HIBERNATION_TESTPROC))
584 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
589 unsigned int flags = 0;
591 if (hibernation_mode == HIBERNATION_PLATFORM)
592 flags |= SF_PLATFORM_MODE;
593 pr_debug("PM: writing image.\n");
594 error = swsusp_write(flags);
599 pr_debug("PM: Image restored successfully.\n");
605 free_basic_memory_bitmaps();
606 usermodehelper_enable();
608 pm_notifier_call_chain(PM_POST_HIBERNATION);
609 pm_restore_console();
610 atomic_inc(&snapshot_device_available);
612 mutex_unlock(&pm_mutex);
618 * software_resume - Resume from a saved image.
620 * Called as a late_initcall (so all devices are discovered and
621 * initialized), we call swsusp to see if we have a saved image or not.
622 * If so, we quiesce devices, the restore the saved image. We will
623 * return above (in hibernate() ) if everything goes well.
624 * Otherwise, we fail gracefully and return to the normally
629 static int software_resume(void)
635 * If the user said "noresume".. bail out early.
641 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
642 * is configured into the kernel. Since the regular hibernate
643 * trigger path is via sysfs which takes a buffer mutex before
644 * calling hibernate functions (which take pm_mutex) this can
645 * cause lockdep to complain about a possible ABBA deadlock
646 * which cannot happen since we're in the boot code here and
647 * sysfs can't be invoked yet. Therefore, we use a subclass
648 * here to avoid lockdep complaining.
650 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
652 if (swsusp_resume_device)
655 if (!strlen(resume_file)) {
660 pr_debug("PM: Checking image partition %s\n", resume_file);
662 /* Check if the device is there */
663 swsusp_resume_device = name_to_dev_t(resume_file);
664 if (!swsusp_resume_device) {
666 * Some device discovery might still be in progress; we need
667 * to wait for this to finish.
669 wait_for_device_probe();
671 * We can't depend on SCSI devices being available after loading
672 * one of their modules until scsi_complete_async_scans() is
673 * called and the resume device usually is a SCSI one.
675 scsi_complete_async_scans();
677 swsusp_resume_device = name_to_dev_t(resume_file);
678 if (!swsusp_resume_device) {
685 pr_debug("PM: Resume from partition %d:%d\n",
686 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
688 pr_debug("PM: Checking hibernation image.\n");
689 error = swsusp_check();
693 /* The snapshot device should not be opened while we're running */
694 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
699 pm_prepare_console();
700 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
704 error = usermodehelper_disable();
708 error = create_basic_memory_bitmaps();
712 pr_debug("PM: Preparing processes for restore.\n");
713 error = prepare_processes();
715 swsusp_close(FMODE_READ);
719 pr_debug("PM: Reading hibernation image.\n");
721 error = swsusp_read(&flags);
723 hibernation_restore(flags & SF_PLATFORM_MODE);
725 printk(KERN_ERR "PM: Restore failed, recovering.\n");
729 free_basic_memory_bitmaps();
730 usermodehelper_enable();
732 pm_notifier_call_chain(PM_POST_RESTORE);
733 pm_restore_console();
734 atomic_inc(&snapshot_device_available);
735 /* For success case, the suspend path will release the lock */
737 mutex_unlock(&pm_mutex);
738 pr_debug("PM: Resume from disk failed.\n");
742 late_initcall(software_resume);
745 static const char * const hibernation_modes[] = {
746 [HIBERNATION_PLATFORM] = "platform",
747 [HIBERNATION_SHUTDOWN] = "shutdown",
748 [HIBERNATION_REBOOT] = "reboot",
749 [HIBERNATION_TEST] = "test",
750 [HIBERNATION_TESTPROC] = "testproc",
754 * disk - Control hibernation mode
756 * Suspend-to-disk can be handled in several ways. We have a few options
757 * for putting the system to sleep - using the platform driver (e.g. ACPI
758 * or other hibernation_ops), powering off the system or rebooting the
759 * system (for testing) as well as the two test modes.
761 * The system can support 'platform', and that is known a priori (and
762 * encoded by the presence of hibernation_ops). However, the user may
763 * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
764 * test modes, 'test' or 'testproc'.
766 * show() will display what the mode is currently set to.
767 * store() will accept one of
775 * It will only change to 'platform' if the system
776 * supports it (as determined by having hibernation_ops).
779 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
785 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
786 if (!hibernation_modes[i])
789 case HIBERNATION_SHUTDOWN:
790 case HIBERNATION_REBOOT:
791 case HIBERNATION_TEST:
792 case HIBERNATION_TESTPROC:
794 case HIBERNATION_PLATFORM:
797 /* not a valid mode, continue with loop */
800 if (i == hibernation_mode)
801 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
803 buf += sprintf(buf, "%s ", hibernation_modes[i]);
805 buf += sprintf(buf, "\n");
810 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
811 const char *buf, size_t n)
817 int mode = HIBERNATION_INVALID;
819 p = memchr(buf, '\n', n);
820 len = p ? p - buf : n;
822 mutex_lock(&pm_mutex);
823 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
824 if (len == strlen(hibernation_modes[i])
825 && !strncmp(buf, hibernation_modes[i], len)) {
830 if (mode != HIBERNATION_INVALID) {
832 case HIBERNATION_SHUTDOWN:
833 case HIBERNATION_REBOOT:
834 case HIBERNATION_TEST:
835 case HIBERNATION_TESTPROC:
836 hibernation_mode = mode;
838 case HIBERNATION_PLATFORM:
840 hibernation_mode = mode;
848 pr_debug("PM: Hibernation mode set to '%s'\n",
849 hibernation_modes[mode]);
850 mutex_unlock(&pm_mutex);
851 return error ? error : n;
856 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
859 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
860 MINOR(swsusp_resume_device));
863 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
864 const char *buf, size_t n)
866 unsigned int maj, min;
870 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
873 res = MKDEV(maj,min);
874 if (maj != MAJOR(res) || min != MINOR(res))
877 mutex_lock(&pm_mutex);
878 swsusp_resume_device = res;
879 mutex_unlock(&pm_mutex);
880 printk(KERN_INFO "PM: Starting manual resume from disk\n");
890 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
893 return sprintf(buf, "%lu\n", image_size);
896 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
897 const char *buf, size_t n)
901 if (sscanf(buf, "%lu", &size) == 1) {
909 power_attr(image_size);
911 static struct attribute * g[] = {
914 &image_size_attr.attr,
919 static struct attribute_group attr_group = {
924 static int __init pm_disk_init(void)
926 return sysfs_create_group(power_kobj, &attr_group);
929 core_initcall(pm_disk_init);
932 static int __init resume_setup(char *str)
937 strncpy( resume_file, str, 255 );
941 static int __init resume_offset_setup(char *str)
943 unsigned long long offset;
948 if (sscanf(str, "%llu", &offset) == 1)
949 swsusp_resume_block = offset;
954 static int __init noresume_setup(char *str)
960 __setup("noresume", noresume_setup);
961 __setup("resume_offset=", resume_offset_setup);
962 __setup("resume=", resume_setup);