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();
279 printk(KERN_ERR "PM: Some system devices failed to power down, "
280 "aborting hibernation\n");
284 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
288 save_processor_state();
289 error = swsusp_arch_suspend();
291 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
293 /* Restore control flow magically appears here */
294 restore_processor_state();
296 events_check_enabled = false;
297 platform_leave(platform_mode);
303 /* NOTE: dpm_resume_noirq() is just a resume() for devices
304 * that suspended with irqs off ... no overall powerup.
311 enable_nonboot_cpus();
314 platform_finish(platform_mode);
316 dpm_resume_noirq(in_suspend ?
317 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
323 * hibernation_snapshot - quiesce devices and create the hibernation
325 * @platform_mode - if set, use the platform driver, if available, to
326 * prepare the platform firmware for the power transition.
328 * Must be called with pm_mutex held
331 int hibernation_snapshot(int platform_mode)
335 error = platform_begin(platform_mode);
339 /* Preallocate image memory before shutting down devices. */
340 error = hibernate_preallocate_memory();
345 pm_restrict_gfp_mask();
346 error = dpm_suspend_start(PMSG_FREEZE);
348 goto Recover_platform;
350 if (hibernation_test(TEST_DEVICES))
351 goto Recover_platform;
353 error = create_image(platform_mode);
355 * Control returns here (1) after the image has been created or the
356 * image creation has failed and (2) after a successful restore.
360 /* We may need to release the preallocated image pages here. */
361 if (error || !in_suspend)
364 dpm_resume_end(in_suspend ?
365 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
367 if (error || !in_suspend)
368 pm_restore_gfp_mask();
372 platform_end(platform_mode);
376 platform_recover(platform_mode);
381 * resume_target_kernel - prepare devices that need to be suspended with
382 * interrupts off, restore the contents of highmem that have not been
383 * restored yet from the image and run the low level code that will restore
384 * the remaining contents of memory and switch to the just restored target
388 static int resume_target_kernel(bool platform_mode)
392 error = dpm_suspend_noirq(PMSG_QUIESCE);
394 printk(KERN_ERR "PM: Some devices failed to power down, "
395 "aborting resume\n");
399 error = platform_pre_restore(platform_mode);
403 error = disable_nonboot_cpus();
409 error = sysdev_suspend(PMSG_QUIESCE);
411 error = syscore_suspend();
415 /* We'll ignore saved state, but this gets preempt count (etc) right */
416 save_processor_state();
417 error = restore_highmem();
419 error = swsusp_arch_resume();
421 * The code below is only ever reached in case of a failure.
422 * Otherwise execution continues at place where
423 * swsusp_arch_suspend() was called
426 /* This call to restore_highmem() undos the previous one */
430 * The only reason why swsusp_arch_resume() can fail is memory being
431 * very tight, so we have to free it as soon as we can to avoid
432 * subsequent failures
435 restore_processor_state();
436 touch_softlockup_watchdog();
445 enable_nonboot_cpus();
448 platform_restore_cleanup(platform_mode);
450 dpm_resume_noirq(PMSG_RECOVER);
456 * hibernation_restore - quiesce devices and restore the hibernation
457 * snapshot image. If successful, control returns in hibernation_snaphot()
458 * @platform_mode - if set, use the platform driver, if available, to
459 * prepare the platform firmware for the transition.
461 * Must be called with pm_mutex held
464 int hibernation_restore(int platform_mode)
468 pm_prepare_console();
470 pm_restrict_gfp_mask();
471 error = dpm_suspend_start(PMSG_QUIESCE);
473 error = resume_target_kernel(platform_mode);
474 dpm_resume_end(PMSG_RECOVER);
476 pm_restore_gfp_mask();
478 pm_restore_console();
483 * hibernation_platform_enter - enter the hibernation state using the
484 * platform driver (if available)
487 int hibernation_platform_enter(void)
491 if (!hibernation_ops)
495 * We have cancelled the power transition by running
496 * hibernation_ops->finish() before saving the image, so we should let
497 * the firmware know that we're going to enter the sleep state after all
499 error = hibernation_ops->begin();
503 entering_platform_hibernation = true;
505 error = dpm_suspend_start(PMSG_HIBERNATE);
507 if (hibernation_ops->recover)
508 hibernation_ops->recover();
512 error = dpm_suspend_noirq(PMSG_HIBERNATE);
516 error = hibernation_ops->prepare();
518 goto Platform_finish;
520 error = disable_nonboot_cpus();
522 goto Platform_finish;
525 sysdev_suspend(PMSG_HIBERNATE);
527 if (pm_wakeup_pending()) {
532 hibernation_ops->enter();
533 /* We should never get here */
540 enable_nonboot_cpus();
543 hibernation_ops->finish();
545 dpm_resume_noirq(PMSG_RESTORE);
548 entering_platform_hibernation = false;
549 dpm_resume_end(PMSG_RESTORE);
553 hibernation_ops->end();
559 * power_down - Shut the machine down for hibernation.
561 * Use the platform driver, if configured so; otherwise try
562 * to power off or reboot.
565 static void power_down(void)
567 switch (hibernation_mode) {
568 case HIBERNATION_TEST:
569 case HIBERNATION_TESTPROC:
571 case HIBERNATION_REBOOT:
572 kernel_restart(NULL);
574 case HIBERNATION_PLATFORM:
575 hibernation_platform_enter();
576 case HIBERNATION_SHUTDOWN:
582 * Valid image is on the disk, if we continue we risk serious data
583 * corruption after resume.
585 printk(KERN_CRIT "PM: Please power down manually\n");
589 static int prepare_processes(void)
593 if (freeze_processes()) {
601 * hibernate - The granpappy of the built-in hibernation management
608 mutex_lock(&pm_mutex);
609 /* The snapshot device should not be opened while we're running */
610 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
615 pm_prepare_console();
616 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
620 error = usermodehelper_disable();
624 /* Allocate memory management structures */
625 error = create_basic_memory_bitmaps();
629 printk(KERN_INFO "PM: Syncing filesystems ... ");
633 error = prepare_processes();
637 if (hibernation_test(TEST_FREEZER))
640 if (hibernation_testmode(HIBERNATION_TESTPROC))
643 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
648 unsigned int flags = 0;
650 if (hibernation_mode == HIBERNATION_PLATFORM)
651 flags |= SF_PLATFORM_MODE;
653 flags |= SF_NOCOMPRESS_MODE;
654 pr_debug("PM: writing image.\n");
655 error = swsusp_write(flags);
660 pm_restore_gfp_mask();
662 pr_debug("PM: Image restored successfully.\n");
668 free_basic_memory_bitmaps();
669 usermodehelper_enable();
671 pm_notifier_call_chain(PM_POST_HIBERNATION);
672 pm_restore_console();
673 atomic_inc(&snapshot_device_available);
675 mutex_unlock(&pm_mutex);
681 * software_resume - Resume from a saved image.
683 * Called as a late_initcall (so all devices are discovered and
684 * initialized), we call swsusp to see if we have a saved image or not.
685 * If so, we quiesce devices, the restore the saved image. We will
686 * return above (in hibernate() ) if everything goes well.
687 * Otherwise, we fail gracefully and return to the normally
692 static int software_resume(void)
698 * If the user said "noresume".. bail out early.
704 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
705 * is configured into the kernel. Since the regular hibernate
706 * trigger path is via sysfs which takes a buffer mutex before
707 * calling hibernate functions (which take pm_mutex) this can
708 * cause lockdep to complain about a possible ABBA deadlock
709 * which cannot happen since we're in the boot code here and
710 * sysfs can't be invoked yet. Therefore, we use a subclass
711 * here to avoid lockdep complaining.
713 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
715 if (swsusp_resume_device)
718 if (!strlen(resume_file)) {
723 pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
725 /* Check if the device is there */
726 swsusp_resume_device = name_to_dev_t(resume_file);
727 if (!swsusp_resume_device) {
729 * Some device discovery might still be in progress; we need
730 * to wait for this to finish.
732 wait_for_device_probe();
734 * We can't depend on SCSI devices being available after loading
735 * one of their modules until scsi_complete_async_scans() is
736 * called and the resume device usually is a SCSI one.
738 scsi_complete_async_scans();
740 swsusp_resume_device = name_to_dev_t(resume_file);
741 if (!swsusp_resume_device) {
748 pr_debug("PM: Hibernation image partition %d:%d present\n",
749 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
751 pr_debug("PM: Looking for hibernation image.\n");
752 error = swsusp_check();
756 /* The snapshot device should not be opened while we're running */
757 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
759 swsusp_close(FMODE_READ);
763 pm_prepare_console();
764 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
768 error = usermodehelper_disable();
772 error = create_basic_memory_bitmaps();
776 pr_debug("PM: Preparing processes for restore.\n");
777 error = prepare_processes();
779 swsusp_close(FMODE_READ);
783 pr_debug("PM: Loading hibernation image.\n");
785 error = swsusp_read(&flags);
786 swsusp_close(FMODE_READ);
788 hibernation_restore(flags & SF_PLATFORM_MODE);
790 printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
794 free_basic_memory_bitmaps();
795 usermodehelper_enable();
797 pm_notifier_call_chain(PM_POST_RESTORE);
798 pm_restore_console();
799 atomic_inc(&snapshot_device_available);
800 /* For success case, the suspend path will release the lock */
802 mutex_unlock(&pm_mutex);
803 pr_debug("PM: Hibernation image not present or could not be loaded.\n");
806 swsusp_close(FMODE_READ);
810 late_initcall(software_resume);
813 static const char * const hibernation_modes[] = {
814 [HIBERNATION_PLATFORM] = "platform",
815 [HIBERNATION_SHUTDOWN] = "shutdown",
816 [HIBERNATION_REBOOT] = "reboot",
817 [HIBERNATION_TEST] = "test",
818 [HIBERNATION_TESTPROC] = "testproc",
822 * disk - Control hibernation mode
824 * Suspend-to-disk can be handled in several ways. We have a few options
825 * for putting the system to sleep - using the platform driver (e.g. ACPI
826 * or other hibernation_ops), powering off the system or rebooting the
827 * system (for testing) as well as the two test modes.
829 * The system can support 'platform', and that is known a priori (and
830 * encoded by the presence of hibernation_ops). However, the user may
831 * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
832 * test modes, 'test' or 'testproc'.
834 * show() will display what the mode is currently set to.
835 * store() will accept one of
843 * It will only change to 'platform' if the system
844 * supports it (as determined by having hibernation_ops).
847 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
853 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
854 if (!hibernation_modes[i])
857 case HIBERNATION_SHUTDOWN:
858 case HIBERNATION_REBOOT:
859 case HIBERNATION_TEST:
860 case HIBERNATION_TESTPROC:
862 case HIBERNATION_PLATFORM:
865 /* not a valid mode, continue with loop */
868 if (i == hibernation_mode)
869 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
871 buf += sprintf(buf, "%s ", hibernation_modes[i]);
873 buf += sprintf(buf, "\n");
878 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
879 const char *buf, size_t n)
885 int mode = HIBERNATION_INVALID;
887 p = memchr(buf, '\n', n);
888 len = p ? p - buf : n;
890 mutex_lock(&pm_mutex);
891 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
892 if (len == strlen(hibernation_modes[i])
893 && !strncmp(buf, hibernation_modes[i], len)) {
898 if (mode != HIBERNATION_INVALID) {
900 case HIBERNATION_SHUTDOWN:
901 case HIBERNATION_REBOOT:
902 case HIBERNATION_TEST:
903 case HIBERNATION_TESTPROC:
904 hibernation_mode = mode;
906 case HIBERNATION_PLATFORM:
908 hibernation_mode = mode;
916 pr_debug("PM: Hibernation mode set to '%s'\n",
917 hibernation_modes[mode]);
918 mutex_unlock(&pm_mutex);
919 return error ? error : n;
924 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
927 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
928 MINOR(swsusp_resume_device));
931 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
932 const char *buf, size_t n)
934 unsigned int maj, min;
938 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
941 res = MKDEV(maj,min);
942 if (maj != MAJOR(res) || min != MINOR(res))
945 mutex_lock(&pm_mutex);
946 swsusp_resume_device = res;
947 mutex_unlock(&pm_mutex);
948 printk(KERN_INFO "PM: Starting manual resume from disk\n");
958 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
961 return sprintf(buf, "%lu\n", image_size);
964 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
965 const char *buf, size_t n)
969 if (sscanf(buf, "%lu", &size) == 1) {
977 power_attr(image_size);
979 static struct attribute * g[] = {
982 &image_size_attr.attr,
987 static struct attribute_group attr_group = {
992 static int __init pm_disk_init(void)
994 return sysfs_create_group(power_kobj, &attr_group);
997 core_initcall(pm_disk_init);
1000 static int __init resume_setup(char *str)
1005 strncpy( resume_file, str, 255 );
1009 static int __init resume_offset_setup(char *str)
1011 unsigned long long offset;
1016 if (sscanf(str, "%llu", &offset) == 1)
1017 swsusp_resume_block = offset;
1022 static int __init hibernate_setup(char *str)
1024 if (!strncmp(str, "noresume", 8))
1026 else if (!strncmp(str, "nocompress", 10))
1031 static int __init noresume_setup(char *str)
1037 __setup("noresume", noresume_setup);
1038 __setup("resume_offset=", resume_offset_setup);
1039 __setup("resume=", resume_setup);
1040 __setup("hibernate=", hibernate_setup);