2 * kernel/power/disk.c - 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>
8 * 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>
29 static int noresume = 0;
30 static char resume_file[256] = CONFIG_PM_STD_PARTITION;
31 dev_t swsusp_resume_device;
32 sector_t swsusp_resume_block;
42 __HIBERNATION_AFTER_LAST
44 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
45 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
47 static int hibernation_mode = HIBERNATION_SHUTDOWN;
49 static struct platform_hibernation_ops *hibernation_ops;
52 * hibernation_set_ops - set the global hibernate operations
53 * @ops: the hibernation operations to use in subsequent hibernation transitions
56 void hibernation_set_ops(struct platform_hibernation_ops *ops)
58 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
59 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
60 && ops->restore_cleanup)) {
64 mutex_lock(&pm_mutex);
65 hibernation_ops = ops;
67 hibernation_mode = HIBERNATION_PLATFORM;
68 else if (hibernation_mode == HIBERNATION_PLATFORM)
69 hibernation_mode = HIBERNATION_SHUTDOWN;
71 mutex_unlock(&pm_mutex);
74 static bool entering_platform_hibernation;
76 bool system_entering_hibernation(void)
78 return entering_platform_hibernation;
80 EXPORT_SYMBOL(system_entering_hibernation);
82 #ifdef CONFIG_PM_DEBUG
83 static void hibernation_debug_sleep(void)
85 printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
89 static int hibernation_testmode(int mode)
91 if (hibernation_mode == mode) {
92 hibernation_debug_sleep();
98 static int hibernation_test(int level)
100 if (pm_test_level == level) {
101 hibernation_debug_sleep();
106 #else /* !CONFIG_PM_DEBUG */
107 static int hibernation_testmode(int mode) { return 0; }
108 static int hibernation_test(int level) { return 0; }
109 #endif /* !CONFIG_PM_DEBUG */
112 * platform_begin - tell the platform driver that we're starting
116 static int platform_begin(int platform_mode)
118 return (platform_mode && hibernation_ops) ?
119 hibernation_ops->begin() : 0;
123 * platform_end - tell the platform driver that we've entered the
127 static void platform_end(int platform_mode)
129 if (platform_mode && hibernation_ops)
130 hibernation_ops->end();
134 * platform_pre_snapshot - prepare the machine for hibernation using the
135 * platform driver if so configured and return an error code if it fails
138 static int platform_pre_snapshot(int platform_mode)
140 return (platform_mode && hibernation_ops) ?
141 hibernation_ops->pre_snapshot() : 0;
145 * platform_leave - prepare the machine for switching to the normal mode
146 * of operation using the platform driver (called with interrupts disabled)
149 static void platform_leave(int platform_mode)
151 if (platform_mode && hibernation_ops)
152 hibernation_ops->leave();
156 * platform_finish - switch the machine to the normal mode of operation
157 * using the platform driver (must be called after platform_prepare())
160 static void platform_finish(int platform_mode)
162 if (platform_mode && hibernation_ops)
163 hibernation_ops->finish();
167 * platform_pre_restore - prepare the platform for the restoration from a
168 * hibernation image. If the restore fails after this function has been
169 * called, platform_restore_cleanup() must be called.
172 static int platform_pre_restore(int platform_mode)
174 return (platform_mode && hibernation_ops) ?
175 hibernation_ops->pre_restore() : 0;
179 * platform_restore_cleanup - switch the platform to the normal mode of
180 * operation after a failing restore. If platform_pre_restore() has been
181 * called before the failing restore, this function must be called too,
182 * regardless of the result of platform_pre_restore().
185 static void platform_restore_cleanup(int platform_mode)
187 if (platform_mode && hibernation_ops)
188 hibernation_ops->restore_cleanup();
192 * platform_recover - recover the platform from a failure to suspend
196 static void platform_recover(int platform_mode)
198 if (platform_mode && hibernation_ops && hibernation_ops->recover)
199 hibernation_ops->recover();
203 * create_image - freeze devices that need to be frozen with interrupts
204 * off, create the hibernation image and thaw those devices. Control
205 * reappears in this routine after a restore.
208 static int create_image(int platform_mode)
212 error = arch_prepare_suspend();
218 /* At this point, device_suspend() has been called, but *not*
219 * device_power_down(). We *must* call device_power_down() 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 = device_power_down(PMSG_FREEZE);
226 printk(KERN_ERR "PM: Some devices failed to power down, "
227 "aborting hibernation\n");
231 if (hibernation_test(TEST_CORE))
235 save_processor_state();
236 error = swsusp_arch_suspend();
238 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
240 /* Restore control flow magically appears here */
241 restore_processor_state();
243 platform_leave(platform_mode);
245 /* NOTE: device_power_up() is just a resume() for devices
246 * that suspended with irqs off ... no overall powerup.
248 device_power_up(in_suspend ?
249 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
257 * hibernation_snapshot - quiesce devices and create the hibernation
259 * @platform_mode - if set, use the platform driver, if available, to
260 * prepare the platform frimware for the power transition.
262 * Must be called with pm_mutex held
265 int hibernation_snapshot(int platform_mode)
269 error = platform_begin(platform_mode);
273 /* Free memory before shutting down devices. */
274 error = swsusp_shrink_memory();
279 error = device_suspend(PMSG_FREEZE);
281 goto Recover_platform;
283 if (hibernation_test(TEST_DEVICES))
284 goto Recover_platform;
286 error = platform_pre_snapshot(platform_mode);
287 if (error || hibernation_test(TEST_PLATFORM))
290 error = disable_nonboot_cpus();
292 if (hibernation_test(TEST_CPUS))
295 if (hibernation_testmode(HIBERNATION_TEST))
298 error = create_image(platform_mode);
299 /* Control returns here after successful restore */
302 enable_nonboot_cpus();
304 platform_finish(platform_mode);
306 device_resume(in_suspend ?
307 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
310 platform_end(platform_mode);
314 platform_recover(platform_mode);
319 * resume_target_kernel - prepare devices that need to be suspended with
320 * interrupts off, restore the contents of highmem that have not been
321 * restored yet from the image and run the low level code that will restore
322 * the remaining contents of memory and switch to the just restored target
326 static int resume_target_kernel(void)
332 error = device_power_down(PMSG_QUIESCE);
334 printk(KERN_ERR "PM: Some devices failed to power down, "
335 "aborting resume\n");
338 /* We'll ignore saved state, but this gets preempt count (etc) right */
339 save_processor_state();
340 error = restore_highmem();
342 error = swsusp_arch_resume();
344 * The code below is only ever reached in case of a failure.
345 * Otherwise execution continues at place where
346 * swsusp_arch_suspend() was called
349 /* This call to restore_highmem() undos the previous one */
353 * The only reason why swsusp_arch_resume() can fail is memory being
354 * very tight, so we have to free it as soon as we can to avoid
355 * subsequent failures
358 restore_processor_state();
359 touch_softlockup_watchdog();
360 device_power_up(PMSG_RECOVER);
368 * hibernation_restore - quiesce devices and restore the hibernation
369 * snapshot image. If successful, control returns in hibernation_snaphot()
370 * @platform_mode - if set, use the platform driver, if available, to
371 * prepare the platform frimware for the transition.
373 * Must be called with pm_mutex held
376 int hibernation_restore(int platform_mode)
380 pm_prepare_console();
382 error = device_suspend(PMSG_QUIESCE);
386 error = platform_pre_restore(platform_mode);
388 error = disable_nonboot_cpus();
390 error = resume_target_kernel();
391 enable_nonboot_cpus();
393 platform_restore_cleanup(platform_mode);
394 device_resume(PMSG_RECOVER);
397 pm_restore_console();
402 * hibernation_platform_enter - enter the hibernation state using the
403 * platform driver (if available)
406 int hibernation_platform_enter(void)
410 if (!hibernation_ops)
414 * We have cancelled the power transition by running
415 * hibernation_ops->finish() before saving the image, so we should let
416 * the firmware know that we're going to enter the sleep state after all
418 error = hibernation_ops->begin();
422 entering_platform_hibernation = true;
424 error = device_suspend(PMSG_HIBERNATE);
426 if (hibernation_ops->recover)
427 hibernation_ops->recover();
431 error = hibernation_ops->prepare();
435 error = disable_nonboot_cpus();
441 error = device_power_down(PMSG_HIBERNATE);
443 hibernation_ops->enter();
444 /* We should never get here */
451 * We don't need to reenable the nonboot CPUs or resume consoles, since
452 * the system is going to be halted anyway.
455 hibernation_ops->finish();
457 entering_platform_hibernation = false;
458 device_resume(PMSG_RESTORE);
461 hibernation_ops->end();
466 * power_down - Shut the machine down for hibernation.
468 * Use the platform driver, if configured so; otherwise try
469 * to power off or reboot.
472 static void power_down(void)
474 switch (hibernation_mode) {
475 case HIBERNATION_TEST:
476 case HIBERNATION_TESTPROC:
478 case HIBERNATION_REBOOT:
479 kernel_restart(NULL);
481 case HIBERNATION_PLATFORM:
482 hibernation_platform_enter();
483 case HIBERNATION_SHUTDOWN:
489 * Valid image is on the disk, if we continue we risk serious data
490 * corruption after resume.
492 printk(KERN_CRIT "PM: Please power down manually\n");
496 static int prepare_processes(void)
500 if (freeze_processes()) {
508 * hibernate - The granpappy of the built-in hibernation management
515 mutex_lock(&pm_mutex);
516 /* The snapshot device should not be opened while we're running */
517 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
522 pm_prepare_console();
523 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
527 error = usermodehelper_disable();
531 /* Allocate memory management structures */
532 error = create_basic_memory_bitmaps();
536 printk(KERN_INFO "PM: Syncing filesystems ... ");
540 error = prepare_processes();
544 if (hibernation_test(TEST_FREEZER))
547 if (hibernation_testmode(HIBERNATION_TESTPROC))
550 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
551 if (in_suspend && !error) {
552 unsigned int flags = 0;
554 if (hibernation_mode == HIBERNATION_PLATFORM)
555 flags |= SF_PLATFORM_MODE;
556 pr_debug("PM: writing image.\n");
557 error = swsusp_write(flags);
562 pr_debug("PM: Image restored successfully.\n");
568 free_basic_memory_bitmaps();
569 usermodehelper_enable();
571 pm_notifier_call_chain(PM_POST_HIBERNATION);
572 pm_restore_console();
573 atomic_inc(&snapshot_device_available);
575 mutex_unlock(&pm_mutex);
581 * software_resume - Resume from a saved image.
583 * Called as a late_initcall (so all devices are discovered and
584 * initialized), we call swsusp to see if we have a saved image or not.
585 * If so, we quiesce devices, the restore the saved image. We will
586 * return above (in hibernate() ) if everything goes well.
587 * Otherwise, we fail gracefully and return to the normally
592 static int software_resume(void)
598 * If the user said "noresume".. bail out early.
604 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
605 * is configured into the kernel. Since the regular hibernate
606 * trigger path is via sysfs which takes a buffer mutex before
607 * calling hibernate functions (which take pm_mutex) this can
608 * cause lockdep to complain about a possible ABBA deadlock
609 * which cannot happen since we're in the boot code here and
610 * sysfs can't be invoked yet. Therefore, we use a subclass
611 * here to avoid lockdep complaining.
613 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
614 if (!swsusp_resume_device) {
615 if (!strlen(resume_file)) {
616 mutex_unlock(&pm_mutex);
620 * Some device discovery might still be in progress; we need
621 * to wait for this to finish.
623 wait_for_device_probe();
624 swsusp_resume_device = name_to_dev_t(resume_file);
625 pr_debug("PM: Resume from partition %s\n", resume_file);
627 pr_debug("PM: Resume from partition %d:%d\n",
628 MAJOR(swsusp_resume_device),
629 MINOR(swsusp_resume_device));
634 * FIXME: If noresume is specified, we need to find the
635 * partition and reset it back to normal swap space.
637 mutex_unlock(&pm_mutex);
641 pr_debug("PM: Checking hibernation image.\n");
642 error = swsusp_check();
646 /* The snapshot device should not be opened while we're running */
647 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
652 pm_prepare_console();
653 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
657 error = usermodehelper_disable();
661 error = create_basic_memory_bitmaps();
665 pr_debug("PM: Preparing processes for restore.\n");
666 error = prepare_processes();
668 swsusp_close(FMODE_READ);
672 pr_debug("PM: Reading hibernation image.\n");
674 error = swsusp_read(&flags);
676 hibernation_restore(flags & SF_PLATFORM_MODE);
678 printk(KERN_ERR "PM: Restore failed, recovering.\n");
682 free_basic_memory_bitmaps();
683 usermodehelper_enable();
685 pm_notifier_call_chain(PM_POST_RESTORE);
686 pm_restore_console();
687 atomic_inc(&snapshot_device_available);
688 /* For success case, the suspend path will release the lock */
690 mutex_unlock(&pm_mutex);
691 pr_debug("PM: Resume from disk failed.\n");
695 late_initcall(software_resume);
698 static const char * const hibernation_modes[] = {
699 [HIBERNATION_PLATFORM] = "platform",
700 [HIBERNATION_SHUTDOWN] = "shutdown",
701 [HIBERNATION_REBOOT] = "reboot",
702 [HIBERNATION_TEST] = "test",
703 [HIBERNATION_TESTPROC] = "testproc",
707 * disk - Control hibernation mode
709 * Suspend-to-disk can be handled in several ways. We have a few options
710 * for putting the system to sleep - using the platform driver (e.g. ACPI
711 * or other hibernation_ops), powering off the system or rebooting the
712 * system (for testing) as well as the two test modes.
714 * The system can support 'platform', and that is known a priori (and
715 * encoded by the presence of hibernation_ops). However, the user may
716 * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
717 * test modes, 'test' or 'testproc'.
719 * show() will display what the mode is currently set to.
720 * store() will accept one of
728 * It will only change to 'platform' if the system
729 * supports it (as determined by having hibernation_ops).
732 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
738 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
739 if (!hibernation_modes[i])
742 case HIBERNATION_SHUTDOWN:
743 case HIBERNATION_REBOOT:
744 case HIBERNATION_TEST:
745 case HIBERNATION_TESTPROC:
747 case HIBERNATION_PLATFORM:
750 /* not a valid mode, continue with loop */
753 if (i == hibernation_mode)
754 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
756 buf += sprintf(buf, "%s ", hibernation_modes[i]);
758 buf += sprintf(buf, "\n");
763 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
764 const char *buf, size_t n)
770 int mode = HIBERNATION_INVALID;
772 p = memchr(buf, '\n', n);
773 len = p ? p - buf : n;
775 mutex_lock(&pm_mutex);
776 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
777 if (len == strlen(hibernation_modes[i])
778 && !strncmp(buf, hibernation_modes[i], len)) {
783 if (mode != HIBERNATION_INVALID) {
785 case HIBERNATION_SHUTDOWN:
786 case HIBERNATION_REBOOT:
787 case HIBERNATION_TEST:
788 case HIBERNATION_TESTPROC:
789 hibernation_mode = mode;
791 case HIBERNATION_PLATFORM:
793 hibernation_mode = mode;
801 pr_debug("PM: Hibernation mode set to '%s'\n",
802 hibernation_modes[mode]);
803 mutex_unlock(&pm_mutex);
804 return error ? error : n;
809 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
812 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
813 MINOR(swsusp_resume_device));
816 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
817 const char *buf, size_t n)
819 unsigned int maj, min;
823 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
826 res = MKDEV(maj,min);
827 if (maj != MAJOR(res) || min != MINOR(res))
830 mutex_lock(&pm_mutex);
831 swsusp_resume_device = res;
832 mutex_unlock(&pm_mutex);
833 printk(KERN_INFO "PM: Starting manual resume from disk\n");
843 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
846 return sprintf(buf, "%lu\n", image_size);
849 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
850 const char *buf, size_t n)
854 if (sscanf(buf, "%lu", &size) == 1) {
862 power_attr(image_size);
864 static struct attribute * g[] = {
867 &image_size_attr.attr,
872 static struct attribute_group attr_group = {
877 static int __init pm_disk_init(void)
879 return sysfs_create_group(power_kobj, &attr_group);
882 core_initcall(pm_disk_init);
885 static int __init resume_setup(char *str)
890 strncpy( resume_file, str, 255 );
894 static int __init resume_offset_setup(char *str)
896 unsigned long long offset;
901 if (sscanf(str, "%llu", &offset) == 1)
902 swsusp_resume_block = offset;
907 static int __init noresume_setup(char *str)
913 __setup("noresume", noresume_setup);
914 __setup("resume_offset=", resume_offset_setup);
915 __setup("resume=", resume_setup);