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>
32 static int nocompress = 0;
33 static int noresume = 0;
34 static char resume_file[256] = CONFIG_PM_STD_PARTITION;
35 dev_t swsusp_resume_device;
36 sector_t swsusp_resume_block;
37 int in_suspend __nosavedata = 0;
47 __HIBERNATION_AFTER_LAST
49 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
50 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
52 static int hibernation_mode = HIBERNATION_SHUTDOWN;
54 static const struct platform_hibernation_ops *hibernation_ops;
57 * hibernation_set_ops - Set the global hibernate operations.
58 * @ops: Hibernation operations to use in subsequent hibernation transitions.
60 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
62 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
63 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
64 && ops->restore_cleanup && ops->leave)) {
68 mutex_lock(&pm_mutex);
69 hibernation_ops = ops;
71 hibernation_mode = HIBERNATION_PLATFORM;
72 else if (hibernation_mode == HIBERNATION_PLATFORM)
73 hibernation_mode = HIBERNATION_SHUTDOWN;
75 mutex_unlock(&pm_mutex);
78 static bool entering_platform_hibernation;
80 bool system_entering_hibernation(void)
82 return entering_platform_hibernation;
84 EXPORT_SYMBOL(system_entering_hibernation);
86 #ifdef CONFIG_PM_DEBUG
87 static void hibernation_debug_sleep(void)
89 printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
93 static int hibernation_testmode(int mode)
95 if (hibernation_mode == mode) {
96 hibernation_debug_sleep();
102 static int hibernation_test(int level)
104 if (pm_test_level == level) {
105 hibernation_debug_sleep();
110 #else /* !CONFIG_PM_DEBUG */
111 static int hibernation_testmode(int mode) { return 0; }
112 static int hibernation_test(int level) { return 0; }
113 #endif /* !CONFIG_PM_DEBUG */
116 * platform_begin - Call platform to start hibernation.
117 * @platform_mode: Whether or not to use the platform driver.
119 static int platform_begin(int platform_mode)
121 return (platform_mode && hibernation_ops) ?
122 hibernation_ops->begin() : 0;
126 * platform_end - Call platform to finish transition to the working state.
127 * @platform_mode: Whether or not to use the platform driver.
129 static void platform_end(int platform_mode)
131 if (platform_mode && hibernation_ops)
132 hibernation_ops->end();
136 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
137 * @platform_mode: Whether or not to use the platform driver.
139 * Use the platform driver to prepare the system for creating a hibernate image,
140 * if so configured, and return an error code if that fails.
143 static int platform_pre_snapshot(int platform_mode)
145 return (platform_mode && hibernation_ops) ?
146 hibernation_ops->pre_snapshot() : 0;
150 * platform_leave - Call platform to prepare a transition to the working state.
151 * @platform_mode: Whether or not to use the platform driver.
153 * Use the platform driver prepare to prepare the machine for switching to the
154 * normal mode of operation.
156 * This routine is called on one CPU with interrupts disabled.
158 static void platform_leave(int platform_mode)
160 if (platform_mode && hibernation_ops)
161 hibernation_ops->leave();
165 * platform_finish - Call platform to switch the system to the working state.
166 * @platform_mode: Whether or not to use the platform driver.
168 * Use the platform driver to switch the machine to the normal mode of
171 * This routine must be called after platform_prepare().
173 static void platform_finish(int platform_mode)
175 if (platform_mode && hibernation_ops)
176 hibernation_ops->finish();
180 * platform_pre_restore - Prepare for hibernate image restoration.
181 * @platform_mode: Whether or not to use the platform driver.
183 * Use the platform driver to prepare the system for resume from a hibernation
186 * If the restore fails after this function has been called,
187 * platform_restore_cleanup() must be called.
189 static int platform_pre_restore(int platform_mode)
191 return (platform_mode && hibernation_ops) ?
192 hibernation_ops->pre_restore() : 0;
196 * platform_restore_cleanup - Switch to the working state after failing restore.
197 * @platform_mode: Whether or not to use the platform driver.
199 * Use the platform driver to switch the system to the normal mode of operation
200 * after a failing restore.
202 * If platform_pre_restore() has been called before the failing restore, this
203 * function must be called too, regardless of the result of
204 * platform_pre_restore().
206 static void platform_restore_cleanup(int platform_mode)
208 if (platform_mode && hibernation_ops)
209 hibernation_ops->restore_cleanup();
213 * platform_recover - Recover from a failure to suspend devices.
214 * @platform_mode: Whether or not to use the platform driver.
216 static void platform_recover(int platform_mode)
218 if (platform_mode && hibernation_ops && hibernation_ops->recover)
219 hibernation_ops->recover();
223 * swsusp_show_speed - Print time elapsed between two events during hibernation.
224 * @start: Starting event.
225 * @stop: Final event.
226 * @nr_pages: Number of memory pages processed between @start and @stop.
227 * @msg: Additional diagnostic message to print.
229 void swsusp_show_speed(struct timeval *start, struct timeval *stop,
230 unsigned nr_pages, char *msg)
232 s64 elapsed_centisecs64;
237 elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
238 do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
239 centisecs = elapsed_centisecs64;
241 centisecs = 1; /* avoid div-by-zero */
242 k = nr_pages * (PAGE_SIZE / 1024);
243 kps = (k * 100) / centisecs;
244 printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
246 centisecs / 100, centisecs % 100,
247 kps / 1000, (kps % 1000) / 10);
251 * create_image - Create a hibernation image.
252 * @platform_mode: Whether or not to use the platform driver.
254 * Execute device drivers' .freeze_noirq() callbacks, create a hibernation image
255 * and execute the drivers' .thaw_noirq() callbacks.
257 * Control reappears in this routine after the subsequent restore.
259 static int create_image(int platform_mode)
263 error = dpm_suspend_noirq(PMSG_FREEZE);
265 printk(KERN_ERR "PM: Some devices failed to power down, "
266 "aborting hibernation\n");
270 error = platform_pre_snapshot(platform_mode);
271 if (error || hibernation_test(TEST_PLATFORM))
272 goto Platform_finish;
274 error = disable_nonboot_cpus();
275 if (error || hibernation_test(TEST_CPUS)
276 || hibernation_testmode(HIBERNATION_TEST))
281 error = syscore_suspend();
283 printk(KERN_ERR "PM: Some system devices failed to power down, "
284 "aborting hibernation\n");
288 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
292 save_processor_state();
293 error = swsusp_arch_suspend();
295 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
297 /* Restore control flow magically appears here */
298 restore_processor_state();
300 events_check_enabled = false;
301 platform_leave(platform_mode);
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 a hibernation image.
324 * @platform_mode: If set, use platform driver to prepare for the transition.
326 * This routine must be called with pm_mutex held.
328 int hibernation_snapshot(int platform_mode)
330 pm_message_t msg = PMSG_RECOVER;
333 error = platform_begin(platform_mode);
337 error = dpm_prepare(PMSG_FREEZE);
339 goto Complete_devices;
341 /* Preallocate image memory before shutting down devices. */
342 error = hibernate_preallocate_memory();
344 goto Complete_devices;
347 pm_restrict_gfp_mask();
348 error = dpm_suspend(PMSG_FREEZE);
350 goto Recover_platform;
352 if (hibernation_test(TEST_DEVICES))
353 goto Recover_platform;
355 error = create_image(platform_mode);
357 * Control returns here (1) after the image has been created or the
358 * image creation has failed and (2) after a successful restore.
362 /* We may need to release the preallocated image pages here. */
363 if (error || !in_suspend)
366 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
369 if (error || !in_suspend)
370 pm_restore_gfp_mask();
378 platform_end(platform_mode);
382 platform_recover(platform_mode);
387 * resume_target_kernel - Restore system state from a hibernation image.
388 * @platform_mode: Whether or not to use the platform driver.
390 * Execute device drivers' .freeze_noirq() callbacks, restore the contents of
391 * highmem that have not been restored yet from the image and run the low-level
392 * code that will restore the remaining contents of memory and switch to the
393 * just restored target kernel.
395 static int resume_target_kernel(bool platform_mode)
399 error = dpm_suspend_noirq(PMSG_QUIESCE);
401 printk(KERN_ERR "PM: Some devices failed to power down, "
402 "aborting resume\n");
406 error = platform_pre_restore(platform_mode);
410 error = disable_nonboot_cpus();
416 error = syscore_suspend();
420 save_processor_state();
421 error = restore_highmem();
423 error = swsusp_arch_resume();
425 * The code below is only ever reached in case of a failure.
426 * Otherwise, execution continues at the place where
427 * swsusp_arch_suspend() was called.
431 * This call to restore_highmem() reverts the changes made by
437 * The only reason why swsusp_arch_resume() can fail is memory being
438 * very tight, so we have to free it as soon as we can to avoid
439 * subsequent failures.
442 restore_processor_state();
443 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 from a hibernation image.
463 * @platform_mode: If set, use platform driver to prepare for the transition.
465 * This routine must be called with pm_mutex held. If it is successful, control
466 * reappears in the restored target kernel in hibernation_snaphot().
468 int hibernation_restore(int platform_mode)
472 pm_prepare_console();
474 pm_restrict_gfp_mask();
475 error = dpm_suspend_start(PMSG_QUIESCE);
477 error = resume_target_kernel(platform_mode);
478 dpm_resume_end(PMSG_RECOVER);
480 pm_restore_gfp_mask();
482 pm_restore_console();
487 * hibernation_platform_enter - Power off the system using the platform driver.
489 int hibernation_platform_enter(void)
493 if (!hibernation_ops)
497 * We have cancelled the power transition by running
498 * hibernation_ops->finish() before saving the image, so we should let
499 * the firmware know that we're going to enter the sleep state after all
501 error = hibernation_ops->begin();
505 entering_platform_hibernation = true;
507 error = dpm_suspend_start(PMSG_HIBERNATE);
509 if (hibernation_ops->recover)
510 hibernation_ops->recover();
514 error = dpm_suspend_noirq(PMSG_HIBERNATE);
518 error = hibernation_ops->prepare();
520 goto Platform_finish;
522 error = disable_nonboot_cpus();
524 goto Platform_finish;
528 if (pm_wakeup_pending()) {
533 hibernation_ops->enter();
534 /* 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, to put the system into the sleep
562 * state corresponding to hibernation, or try to power it off or reboot,
563 * depending on the value of hibernation_mode.
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 - Carry out system hibernation, including saving the image.
607 mutex_lock(&pm_mutex);
608 /* The snapshot device should not be opened while we're running */
609 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
614 pm_prepare_console();
615 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
619 error = usermodehelper_disable();
623 /* Allocate memory management structures */
624 error = create_basic_memory_bitmaps();
628 printk(KERN_INFO "PM: Syncing filesystems ... ");
632 error = prepare_processes();
636 if (hibernation_test(TEST_FREEZER))
639 if (hibernation_testmode(HIBERNATION_TESTPROC))
642 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
647 unsigned int flags = 0;
649 if (hibernation_mode == HIBERNATION_PLATFORM)
650 flags |= SF_PLATFORM_MODE;
652 flags |= SF_NOCOMPRESS_MODE;
653 pr_debug("PM: writing image.\n");
654 error = swsusp_write(flags);
659 pm_restore_gfp_mask();
661 pr_debug("PM: Image restored successfully.\n");
667 free_basic_memory_bitmaps();
668 usermodehelper_enable();
670 pm_notifier_call_chain(PM_POST_HIBERNATION);
671 pm_restore_console();
672 atomic_inc(&snapshot_device_available);
674 mutex_unlock(&pm_mutex);
680 * software_resume - Resume from a saved hibernation image.
682 * This routine is called as a late initcall, when all devices have been
683 * discovered and initialized already.
685 * The image reading code is called to see if there is a hibernation image
686 * available for reading. If that is the case, devices are quiesced and the
687 * contents of memory is restored from the saved image.
689 * If this is successful, control reappears in the restored target kernel in
690 * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine
691 * attempts to recover gracefully and make the kernel return to the normal mode
694 static int software_resume(void)
700 * If the user said "noresume".. bail out early.
706 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
707 * is configured into the kernel. Since the regular hibernate
708 * trigger path is via sysfs which takes a buffer mutex before
709 * calling hibernate functions (which take pm_mutex) this can
710 * cause lockdep to complain about a possible ABBA deadlock
711 * which cannot happen since we're in the boot code here and
712 * sysfs can't be invoked yet. Therefore, we use a subclass
713 * here to avoid lockdep complaining.
715 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
717 if (swsusp_resume_device)
720 if (!strlen(resume_file)) {
725 pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
727 /* Check if the device is there */
728 swsusp_resume_device = name_to_dev_t(resume_file);
729 if (!swsusp_resume_device) {
731 * Some device discovery might still be in progress; we need
732 * to wait for this to finish.
734 wait_for_device_probe();
736 * We can't depend on SCSI devices being available after loading
737 * one of their modules until scsi_complete_async_scans() is
738 * called and the resume device usually is a SCSI one.
740 scsi_complete_async_scans();
742 swsusp_resume_device = name_to_dev_t(resume_file);
743 if (!swsusp_resume_device) {
750 pr_debug("PM: Hibernation image partition %d:%d present\n",
751 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
753 pr_debug("PM: Looking for hibernation image.\n");
754 error = swsusp_check();
758 /* The snapshot device should not be opened while we're running */
759 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
761 swsusp_close(FMODE_READ);
765 pm_prepare_console();
766 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
770 error = usermodehelper_disable();
774 error = create_basic_memory_bitmaps();
778 pr_debug("PM: Preparing processes for restore.\n");
779 error = prepare_processes();
781 swsusp_close(FMODE_READ);
785 pr_debug("PM: Loading hibernation image.\n");
787 error = swsusp_read(&flags);
788 swsusp_close(FMODE_READ);
790 hibernation_restore(flags & SF_PLATFORM_MODE);
792 printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
796 free_basic_memory_bitmaps();
797 usermodehelper_enable();
799 pm_notifier_call_chain(PM_POST_RESTORE);
800 pm_restore_console();
801 atomic_inc(&snapshot_device_available);
802 /* For success case, the suspend path will release the lock */
804 mutex_unlock(&pm_mutex);
805 pr_debug("PM: Hibernation image not present or could not be loaded.\n");
808 swsusp_close(FMODE_READ);
812 late_initcall(software_resume);
815 static const char * const hibernation_modes[] = {
816 [HIBERNATION_PLATFORM] = "platform",
817 [HIBERNATION_SHUTDOWN] = "shutdown",
818 [HIBERNATION_REBOOT] = "reboot",
819 [HIBERNATION_TEST] = "test",
820 [HIBERNATION_TESTPROC] = "testproc",
824 * /sys/power/disk - Control hibernation mode.
826 * Hibernation can be handled in several ways. There are a few different ways
827 * to put the system into the sleep state: using the platform driver (e.g. ACPI
828 * or other hibernation_ops), powering it off or rebooting it (for testing
829 * mostly), or using one of the two available test modes.
831 * The sysfs file /sys/power/disk provides an interface for selecting the
832 * hibernation mode to use. Reading from this file causes the available modes
833 * to be printed. There are 5 modes that can be supported:
841 * If a platform hibernation driver is in use, 'platform' will be supported
842 * and will be used by default. Otherwise, 'shutdown' will be used by default.
843 * The selected option (i.e. the one corresponding to the current value of
844 * hibernation_mode) is enclosed by a square bracket.
846 * To select a given hibernation mode it is necessary to write the mode's
847 * string representation (as returned by reading from /sys/power/disk) back
848 * into /sys/power/disk.
851 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
857 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
858 if (!hibernation_modes[i])
861 case HIBERNATION_SHUTDOWN:
862 case HIBERNATION_REBOOT:
863 case HIBERNATION_TEST:
864 case HIBERNATION_TESTPROC:
866 case HIBERNATION_PLATFORM:
869 /* not a valid mode, continue with loop */
872 if (i == hibernation_mode)
873 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
875 buf += sprintf(buf, "%s ", hibernation_modes[i]);
877 buf += sprintf(buf, "\n");
881 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
882 const char *buf, size_t n)
888 int mode = HIBERNATION_INVALID;
890 p = memchr(buf, '\n', n);
891 len = p ? p - buf : n;
893 mutex_lock(&pm_mutex);
894 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
895 if (len == strlen(hibernation_modes[i])
896 && !strncmp(buf, hibernation_modes[i], len)) {
901 if (mode != HIBERNATION_INVALID) {
903 case HIBERNATION_SHUTDOWN:
904 case HIBERNATION_REBOOT:
905 case HIBERNATION_TEST:
906 case HIBERNATION_TESTPROC:
907 hibernation_mode = mode;
909 case HIBERNATION_PLATFORM:
911 hibernation_mode = mode;
919 pr_debug("PM: Hibernation mode set to '%s'\n",
920 hibernation_modes[mode]);
921 mutex_unlock(&pm_mutex);
922 return error ? error : n;
927 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
930 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
931 MINOR(swsusp_resume_device));
934 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
935 const char *buf, size_t n)
937 unsigned int maj, min;
941 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
944 res = MKDEV(maj,min);
945 if (maj != MAJOR(res) || min != MINOR(res))
948 mutex_lock(&pm_mutex);
949 swsusp_resume_device = res;
950 mutex_unlock(&pm_mutex);
951 printk(KERN_INFO "PM: Starting manual resume from disk\n");
961 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
964 return sprintf(buf, "%lu\n", image_size);
967 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
968 const char *buf, size_t n)
972 if (sscanf(buf, "%lu", &size) == 1) {
980 power_attr(image_size);
982 static ssize_t reserved_size_show(struct kobject *kobj,
983 struct kobj_attribute *attr, char *buf)
985 return sprintf(buf, "%lu\n", reserved_size);
988 static ssize_t reserved_size_store(struct kobject *kobj,
989 struct kobj_attribute *attr,
990 const char *buf, size_t n)
994 if (sscanf(buf, "%lu", &size) == 1) {
995 reserved_size = size;
1002 power_attr(reserved_size);
1004 static struct attribute * g[] = {
1007 &image_size_attr.attr,
1008 &reserved_size_attr.attr,
1013 static struct attribute_group attr_group = {
1018 static int __init pm_disk_init(void)
1020 return sysfs_create_group(power_kobj, &attr_group);
1023 core_initcall(pm_disk_init);
1026 static int __init resume_setup(char *str)
1031 strncpy( resume_file, str, 255 );
1035 static int __init resume_offset_setup(char *str)
1037 unsigned long long offset;
1042 if (sscanf(str, "%llu", &offset) == 1)
1043 swsusp_resume_block = offset;
1048 static int __init hibernate_setup(char *str)
1050 if (!strncmp(str, "noresume", 8))
1052 else if (!strncmp(str, "nocompress", 10))
1057 static int __init noresume_setup(char *str)
1063 __setup("noresume", noresume_setup);
1064 __setup("resume_offset=", resume_offset_setup);
1065 __setup("resume=", resume_setup);
1066 __setup("hibernate=", hibernate_setup);