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@ucw.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 <linux/gfp.h>
26 #include <linux/syscore_ops.h>
27 #include <scsi/scsi_scan.h>
28 #include <asm/suspend.h>
33 static int nocompress = 0;
34 static int noresume = 0;
35 static char resume_file[256] = CONFIG_PM_STD_PARTITION;
36 dev_t swsusp_resume_device;
37 sector_t swsusp_resume_block;
38 int in_suspend __nosavedata = 0;
48 __HIBERNATION_AFTER_LAST
50 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
51 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
53 static int hibernation_mode = HIBERNATION_SHUTDOWN;
55 static const struct platform_hibernation_ops *hibernation_ops;
58 * hibernation_set_ops - set the global hibernate operations
59 * @ops: the hibernation operations to use in subsequent hibernation transitions
62 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
64 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
65 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
66 && ops->restore_cleanup && ops->leave)) {
70 mutex_lock(&pm_mutex);
71 hibernation_ops = ops;
73 hibernation_mode = HIBERNATION_PLATFORM;
74 else if (hibernation_mode == HIBERNATION_PLATFORM)
75 hibernation_mode = HIBERNATION_SHUTDOWN;
77 mutex_unlock(&pm_mutex);
80 static bool entering_platform_hibernation;
82 bool system_entering_hibernation(void)
84 return entering_platform_hibernation;
86 EXPORT_SYMBOL(system_entering_hibernation);
88 #ifdef CONFIG_PM_DEBUG
89 static void hibernation_debug_sleep(void)
91 printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
95 static int hibernation_testmode(int mode)
97 if (hibernation_mode == mode) {
98 hibernation_debug_sleep();
104 static int hibernation_test(int level)
106 if (pm_test_level == level) {
107 hibernation_debug_sleep();
112 #else /* !CONFIG_PM_DEBUG */
113 static int hibernation_testmode(int mode) { return 0; }
114 static int hibernation_test(int level) { return 0; }
115 #endif /* !CONFIG_PM_DEBUG */
118 * platform_begin - tell the platform driver that we're starting
122 static int platform_begin(int platform_mode)
124 return (platform_mode && hibernation_ops) ?
125 hibernation_ops->begin() : 0;
129 * platform_end - tell the platform driver that we've entered the
133 static void platform_end(int platform_mode)
135 if (platform_mode && hibernation_ops)
136 hibernation_ops->end();
140 * platform_pre_snapshot - prepare the machine for hibernation using the
141 * platform driver if so configured and return an error code if it fails
144 static int platform_pre_snapshot(int platform_mode)
146 return (platform_mode && hibernation_ops) ?
147 hibernation_ops->pre_snapshot() : 0;
151 * platform_leave - prepare the machine for switching to the normal mode
152 * of operation using the platform driver (called with interrupts disabled)
155 static void platform_leave(int platform_mode)
157 if (platform_mode && hibernation_ops)
158 hibernation_ops->leave();
162 * platform_finish - switch the machine to the normal mode of operation
163 * using the platform driver (must be called after platform_prepare())
166 static void platform_finish(int platform_mode)
168 if (platform_mode && hibernation_ops)
169 hibernation_ops->finish();
173 * platform_pre_restore - prepare the platform for the restoration from a
174 * hibernation image. If the restore fails after this function has been
175 * called, platform_restore_cleanup() must be called.
178 static int platform_pre_restore(int platform_mode)
180 return (platform_mode && hibernation_ops) ?
181 hibernation_ops->pre_restore() : 0;
185 * platform_restore_cleanup - switch the platform to the normal mode of
186 * operation after a failing restore. If platform_pre_restore() has been
187 * called before the failing restore, this function must be called too,
188 * regardless of the result of platform_pre_restore().
191 static void platform_restore_cleanup(int platform_mode)
193 if (platform_mode && hibernation_ops)
194 hibernation_ops->restore_cleanup();
198 * platform_recover - recover the platform from a failure to suspend
202 static void platform_recover(int platform_mode)
204 if (platform_mode && hibernation_ops && hibernation_ops->recover)
205 hibernation_ops->recover();
209 * swsusp_show_speed - print the time elapsed between two events.
210 * @start: Starting event.
211 * @stop: Final event.
212 * @nr_pages - number of pages processed between @start and @stop
213 * @msg - introductory message to print
216 void swsusp_show_speed(struct timeval *start, struct timeval *stop,
217 unsigned nr_pages, char *msg)
219 s64 elapsed_centisecs64;
224 elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
225 do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
226 centisecs = elapsed_centisecs64;
228 centisecs = 1; /* avoid div-by-zero */
229 k = nr_pages * (PAGE_SIZE / 1024);
230 kps = (k * 100) / centisecs;
231 printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
233 centisecs / 100, centisecs % 100,
234 kps / 1000, (kps % 1000) / 10);
238 * create_image - freeze devices that need to be frozen with interrupts
239 * off, create the hibernation image and thaw those devices. Control
240 * reappears in this routine after a restore.
243 static int create_image(int platform_mode)
247 error = arch_prepare_suspend();
251 /* At this point, dpm_suspend_start() has been called, but *not*
252 * dpm_suspend_noirq(). We *must* call dpm_suspend_noirq() now.
253 * Otherwise, drivers for some devices (e.g. interrupt controllers)
254 * become desynchronized with the actual state of the hardware
255 * at resume time, and evil weirdness ensues.
257 error = dpm_suspend_noirq(PMSG_FREEZE);
259 printk(KERN_ERR "PM: Some devices failed to power down, "
260 "aborting hibernation\n");
264 error = platform_pre_snapshot(platform_mode);
265 if (error || hibernation_test(TEST_PLATFORM))
266 goto Platform_finish;
268 error = disable_nonboot_cpus();
269 if (error || hibernation_test(TEST_CPUS)
270 || hibernation_testmode(HIBERNATION_TEST))
275 error = sysdev_suspend(PMSG_FREEZE);
277 error = syscore_suspend();
282 printk(KERN_ERR "PM: Some system devices failed to power down, "
283 "aborting hibernation\n");
287 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
291 save_processor_state();
292 error = swsusp_arch_suspend();
294 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
296 /* Restore control flow magically appears here */
297 restore_processor_state();
299 events_check_enabled = false;
300 platform_leave(platform_mode);
306 /* NOTE: dpm_resume_noirq() is just a resume() for devices
307 * that suspended with irqs off ... no overall powerup.
314 enable_nonboot_cpus();
317 platform_finish(platform_mode);
319 dpm_resume_noirq(in_suspend ?
320 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
326 * hibernation_snapshot - quiesce devices and create the hibernation
328 * @platform_mode - if set, use the platform driver, if available, to
329 * prepare the platform firmware for the power transition.
331 * Must be called with pm_mutex held
334 int hibernation_snapshot(int platform_mode)
338 error = platform_begin(platform_mode);
342 /* Preallocate image memory before shutting down devices. */
343 error = hibernate_preallocate_memory();
348 pm_restrict_gfp_mask();
349 error = dpm_suspend_start(PMSG_FREEZE);
351 goto Recover_platform;
353 if (hibernation_test(TEST_DEVICES))
354 goto Recover_platform;
356 error = create_image(platform_mode);
358 * Control returns here (1) after the image has been created or the
359 * image creation has failed and (2) after a successful restore.
363 /* We may need to release the preallocated image pages here. */
364 if (error || !in_suspend)
367 dpm_resume_end(in_suspend ?
368 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
370 if (error || !in_suspend)
371 pm_restore_gfp_mask();
375 platform_end(platform_mode);
379 platform_recover(platform_mode);
384 * resume_target_kernel - prepare devices that need to be suspended with
385 * interrupts off, restore the contents of highmem that have not been
386 * restored yet from the image and run the low level code that will restore
387 * the remaining contents of memory and switch to the just restored target
391 static int resume_target_kernel(bool platform_mode)
395 error = dpm_suspend_noirq(PMSG_QUIESCE);
397 printk(KERN_ERR "PM: Some devices failed to power down, "
398 "aborting resume\n");
402 error = platform_pre_restore(platform_mode);
406 error = disable_nonboot_cpus();
412 error = sysdev_suspend(PMSG_QUIESCE);
414 error = syscore_suspend();
421 /* We'll ignore saved state, but this gets preempt count (etc) right */
422 save_processor_state();
423 error = restore_highmem();
425 error = swsusp_arch_resume();
427 * The code below is only ever reached in case of a failure.
428 * Otherwise execution continues at place where
429 * swsusp_arch_suspend() was called
432 /* This call to restore_highmem() undos the previous one */
436 * The only reason why swsusp_arch_resume() can fail is memory being
437 * very tight, so we have to free it as soon as we can to avoid
438 * subsequent failures
441 restore_processor_state();
442 touch_softlockup_watchdog();
451 enable_nonboot_cpus();
454 platform_restore_cleanup(platform_mode);
456 dpm_resume_noirq(PMSG_RECOVER);
462 * hibernation_restore - quiesce devices and restore the hibernation
463 * snapshot image. If successful, control returns in hibernation_snaphot()
464 * @platform_mode - if set, use the platform driver, if available, to
465 * prepare the platform firmware for the transition.
467 * Must be called with pm_mutex held
470 int hibernation_restore(int platform_mode)
474 pm_prepare_console();
476 pm_restrict_gfp_mask();
477 error = dpm_suspend_start(PMSG_QUIESCE);
479 error = resume_target_kernel(platform_mode);
480 dpm_resume_end(PMSG_RECOVER);
482 pm_restore_gfp_mask();
484 pm_restore_console();
489 * hibernation_platform_enter - enter the hibernation state using the
490 * platform driver (if available)
493 int hibernation_platform_enter(void)
497 if (!hibernation_ops)
501 * We have cancelled the power transition by running
502 * hibernation_ops->finish() before saving the image, so we should let
503 * the firmware know that we're going to enter the sleep state after all
505 error = hibernation_ops->begin();
509 entering_platform_hibernation = true;
511 error = dpm_suspend_start(PMSG_HIBERNATE);
513 if (hibernation_ops->recover)
514 hibernation_ops->recover();
518 error = dpm_suspend_noirq(PMSG_HIBERNATE);
522 error = hibernation_ops->prepare();
524 goto Platform_finish;
526 error = disable_nonboot_cpus();
528 goto Platform_finish;
531 sysdev_suspend(PMSG_HIBERNATE);
533 if (pm_wakeup_pending()) {
538 hibernation_ops->enter();
539 /* We should never get here */
546 enable_nonboot_cpus();
549 hibernation_ops->finish();
551 dpm_resume_noirq(PMSG_RESTORE);
554 entering_platform_hibernation = false;
555 dpm_resume_end(PMSG_RESTORE);
559 hibernation_ops->end();
565 * power_down - Shut the machine down for hibernation.
567 * Use the platform driver, if configured so; otherwise try
568 * to power off or reboot.
571 static void power_down(void)
573 switch (hibernation_mode) {
574 case HIBERNATION_TEST:
575 case HIBERNATION_TESTPROC:
577 case HIBERNATION_REBOOT:
578 kernel_restart(NULL);
580 case HIBERNATION_PLATFORM:
581 hibernation_platform_enter();
582 case HIBERNATION_SHUTDOWN:
588 * Valid image is on the disk, if we continue we risk serious data
589 * corruption after resume.
591 printk(KERN_CRIT "PM: Please power down manually\n");
595 static int prepare_processes(void)
599 if (freeze_processes()) {
607 * hibernate - The granpappy of the built-in hibernation management
614 mutex_lock(&pm_mutex);
615 /* The snapshot device should not be opened while we're running */
616 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
621 pm_prepare_console();
622 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
626 error = usermodehelper_disable();
630 /* Allocate memory management structures */
631 error = create_basic_memory_bitmaps();
635 printk(KERN_INFO "PM: Syncing filesystems ... ");
639 error = prepare_processes();
643 if (hibernation_test(TEST_FREEZER))
646 if (hibernation_testmode(HIBERNATION_TESTPROC))
649 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
654 unsigned int flags = 0;
656 if (hibernation_mode == HIBERNATION_PLATFORM)
657 flags |= SF_PLATFORM_MODE;
659 flags |= SF_NOCOMPRESS_MODE;
660 pr_debug("PM: writing image.\n");
661 error = swsusp_write(flags);
666 pm_restore_gfp_mask();
668 pr_debug("PM: Image restored successfully.\n");
674 free_basic_memory_bitmaps();
675 usermodehelper_enable();
677 pm_notifier_call_chain(PM_POST_HIBERNATION);
678 pm_restore_console();
679 atomic_inc(&snapshot_device_available);
681 mutex_unlock(&pm_mutex);
687 * software_resume - Resume from a saved image.
689 * Called as a late_initcall (so all devices are discovered and
690 * initialized), we call swsusp to see if we have a saved image or not.
691 * If so, we quiesce devices, the restore the saved image. We will
692 * return above (in hibernate() ) if everything goes well.
693 * Otherwise, we fail gracefully and return to the normally
698 static int software_resume(void)
704 * If the user said "noresume".. bail out early.
710 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
711 * is configured into the kernel. Since the regular hibernate
712 * trigger path is via sysfs which takes a buffer mutex before
713 * calling hibernate functions (which take pm_mutex) this can
714 * cause lockdep to complain about a possible ABBA deadlock
715 * which cannot happen since we're in the boot code here and
716 * sysfs can't be invoked yet. Therefore, we use a subclass
717 * here to avoid lockdep complaining.
719 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
721 if (swsusp_resume_device)
724 if (!strlen(resume_file)) {
729 pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
731 /* Check if the device is there */
732 swsusp_resume_device = name_to_dev_t(resume_file);
733 if (!swsusp_resume_device) {
735 * Some device discovery might still be in progress; we need
736 * to wait for this to finish.
738 wait_for_device_probe();
740 * We can't depend on SCSI devices being available after loading
741 * one of their modules until scsi_complete_async_scans() is
742 * called and the resume device usually is a SCSI one.
744 scsi_complete_async_scans();
746 swsusp_resume_device = name_to_dev_t(resume_file);
747 if (!swsusp_resume_device) {
754 pr_debug("PM: Hibernation image partition %d:%d present\n",
755 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
757 pr_debug("PM: Looking for hibernation image.\n");
758 error = swsusp_check();
762 /* The snapshot device should not be opened while we're running */
763 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
765 swsusp_close(FMODE_READ);
769 pm_prepare_console();
770 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
774 error = usermodehelper_disable();
778 error = create_basic_memory_bitmaps();
782 pr_debug("PM: Preparing processes for restore.\n");
783 error = prepare_processes();
785 swsusp_close(FMODE_READ);
789 pr_debug("PM: Loading hibernation image.\n");
791 error = swsusp_read(&flags);
792 swsusp_close(FMODE_READ);
794 hibernation_restore(flags & SF_PLATFORM_MODE);
796 printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
800 free_basic_memory_bitmaps();
801 usermodehelper_enable();
803 pm_notifier_call_chain(PM_POST_RESTORE);
804 pm_restore_console();
805 atomic_inc(&snapshot_device_available);
806 /* For success case, the suspend path will release the lock */
808 mutex_unlock(&pm_mutex);
809 pr_debug("PM: Hibernation image not present or could not be loaded.\n");
812 swsusp_close(FMODE_READ);
816 late_initcall(software_resume);
819 static const char * const hibernation_modes[] = {
820 [HIBERNATION_PLATFORM] = "platform",
821 [HIBERNATION_SHUTDOWN] = "shutdown",
822 [HIBERNATION_REBOOT] = "reboot",
823 [HIBERNATION_TEST] = "test",
824 [HIBERNATION_TESTPROC] = "testproc",
828 * disk - Control hibernation mode
830 * Suspend-to-disk can be handled in several ways. We have a few options
831 * for putting the system to sleep - using the platform driver (e.g. ACPI
832 * or other hibernation_ops), powering off the system or rebooting the
833 * system (for testing) as well as the two test modes.
835 * The system can support 'platform', and that is known a priori (and
836 * encoded by the presence of hibernation_ops). However, the user may
837 * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
838 * test modes, 'test' or 'testproc'.
840 * show() will display what the mode is currently set to.
841 * store() will accept one of
849 * It will only change to 'platform' if the system
850 * supports it (as determined by having hibernation_ops).
853 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
859 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
860 if (!hibernation_modes[i])
863 case HIBERNATION_SHUTDOWN:
864 case HIBERNATION_REBOOT:
865 case HIBERNATION_TEST:
866 case HIBERNATION_TESTPROC:
868 case HIBERNATION_PLATFORM:
871 /* not a valid mode, continue with loop */
874 if (i == hibernation_mode)
875 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
877 buf += sprintf(buf, "%s ", hibernation_modes[i]);
879 buf += sprintf(buf, "\n");
884 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
885 const char *buf, size_t n)
891 int mode = HIBERNATION_INVALID;
893 p = memchr(buf, '\n', n);
894 len = p ? p - buf : n;
896 mutex_lock(&pm_mutex);
897 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
898 if (len == strlen(hibernation_modes[i])
899 && !strncmp(buf, hibernation_modes[i], len)) {
904 if (mode != HIBERNATION_INVALID) {
906 case HIBERNATION_SHUTDOWN:
907 case HIBERNATION_REBOOT:
908 case HIBERNATION_TEST:
909 case HIBERNATION_TESTPROC:
910 hibernation_mode = mode;
912 case HIBERNATION_PLATFORM:
914 hibernation_mode = mode;
922 pr_debug("PM: Hibernation mode set to '%s'\n",
923 hibernation_modes[mode]);
924 mutex_unlock(&pm_mutex);
925 return error ? error : n;
930 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
933 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
934 MINOR(swsusp_resume_device));
937 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
938 const char *buf, size_t n)
940 unsigned int maj, min;
944 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
947 res = MKDEV(maj,min);
948 if (maj != MAJOR(res) || min != MINOR(res))
951 mutex_lock(&pm_mutex);
952 swsusp_resume_device = res;
953 mutex_unlock(&pm_mutex);
954 printk(KERN_INFO "PM: Starting manual resume from disk\n");
964 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
967 return sprintf(buf, "%lu\n", image_size);
970 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
971 const char *buf, size_t n)
975 if (sscanf(buf, "%lu", &size) == 1) {
983 power_attr(image_size);
985 static struct attribute * g[] = {
988 &image_size_attr.attr,
993 static struct attribute_group attr_group = {
998 static int __init pm_disk_init(void)
1000 return sysfs_create_group(power_kobj, &attr_group);
1003 core_initcall(pm_disk_init);
1006 static int __init resume_setup(char *str)
1011 strncpy( resume_file, str, 255 );
1015 static int __init resume_offset_setup(char *str)
1017 unsigned long long offset;
1022 if (sscanf(str, "%llu", &offset) == 1)
1023 swsusp_resume_block = offset;
1028 static int __init hibernate_setup(char *str)
1030 if (!strncmp(str, "noresume", 8))
1032 else if (!strncmp(str, "nocompress", 10))
1037 static int __init noresume_setup(char *str)
1043 __setup("noresume", noresume_setup);
1044 __setup("resume_offset=", resume_offset_setup);
1045 __setup("resume=", resume_setup);
1046 __setup("hibernate=", hibernate_setup);