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/delay.h>
19 #include <linux/mount.h>
21 #include <linux/console.h>
22 #include <linux/cpu.h>
23 #include <linux/freezer.h>
28 static int noresume = 0;
29 static char resume_file[256] = CONFIG_PM_STD_PARTITION;
30 dev_t swsusp_resume_device;
31 sector_t swsusp_resume_block;
41 __HIBERNATION_AFTER_LAST
43 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
44 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
46 static int hibernation_mode = HIBERNATION_SHUTDOWN;
48 static struct platform_hibernation_ops *hibernation_ops;
51 * hibernation_set_ops - set the global hibernate operations
52 * @ops: the hibernation operations to use in subsequent hibernation transitions
55 void hibernation_set_ops(struct platform_hibernation_ops *ops)
57 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
58 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
59 && ops->restore_cleanup)) {
63 mutex_lock(&pm_mutex);
64 hibernation_ops = ops;
66 hibernation_mode = HIBERNATION_PLATFORM;
67 else if (hibernation_mode == HIBERNATION_PLATFORM)
68 hibernation_mode = HIBERNATION_SHUTDOWN;
70 mutex_unlock(&pm_mutex);
73 #ifdef CONFIG_PM_DEBUG
74 static void hibernation_debug_sleep(void)
76 printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
80 static int hibernation_testmode(int mode)
82 if (hibernation_mode == mode) {
83 hibernation_debug_sleep();
89 static int hibernation_test(int level)
91 if (pm_test_level == level) {
92 hibernation_debug_sleep();
97 #else /* !CONFIG_PM_DEBUG */
98 static int hibernation_testmode(int mode) { return 0; }
99 static int hibernation_test(int level) { return 0; }
100 #endif /* !CONFIG_PM_DEBUG */
103 * platform_begin - tell the platform driver that we're starting
107 static int platform_begin(int platform_mode)
109 return (platform_mode && hibernation_ops) ?
110 hibernation_ops->begin() : 0;
114 * platform_end - tell the platform driver that we've entered the
118 static void platform_end(int platform_mode)
120 if (platform_mode && hibernation_ops)
121 hibernation_ops->end();
125 * platform_pre_snapshot - prepare the machine for hibernation using the
126 * platform driver if so configured and return an error code if it fails
129 static int platform_pre_snapshot(int platform_mode)
131 return (platform_mode && hibernation_ops) ?
132 hibernation_ops->pre_snapshot() : 0;
136 * platform_leave - prepare the machine for switching to the normal mode
137 * of operation using the platform driver (called with interrupts disabled)
140 static void platform_leave(int platform_mode)
142 if (platform_mode && hibernation_ops)
143 hibernation_ops->leave();
147 * platform_finish - switch the machine to the normal mode of operation
148 * using the platform driver (must be called after platform_prepare())
151 static void platform_finish(int platform_mode)
153 if (platform_mode && hibernation_ops)
154 hibernation_ops->finish();
158 * platform_pre_restore - prepare the platform for the restoration from a
159 * hibernation image. If the restore fails after this function has been
160 * called, platform_restore_cleanup() must be called.
163 static int platform_pre_restore(int platform_mode)
165 return (platform_mode && hibernation_ops) ?
166 hibernation_ops->pre_restore() : 0;
170 * platform_restore_cleanup - switch the platform to the normal mode of
171 * operation after a failing restore. If platform_pre_restore() has been
172 * called before the failing restore, this function must be called too,
173 * regardless of the result of platform_pre_restore().
176 static void platform_restore_cleanup(int platform_mode)
178 if (platform_mode && hibernation_ops)
179 hibernation_ops->restore_cleanup();
183 * create_image - freeze devices that need to be frozen with interrupts
184 * off, create the hibernation image and thaw those devices. Control
185 * reappears in this routine after a restore.
188 static int create_image(int platform_mode)
192 error = arch_prepare_suspend();
198 /* At this point, device_suspend() has been called, but *not*
199 * device_power_down(). We *must* call device_power_down() now.
200 * Otherwise, drivers for some devices (e.g. interrupt controllers)
201 * become desynchronized with the actual state of the hardware
202 * at resume time, and evil weirdness ensues.
204 error = device_power_down(PMSG_FREEZE);
206 printk(KERN_ERR "PM: Some devices failed to power down, "
207 "aborting hibernation\n");
211 if (hibernation_test(TEST_CORE))
215 save_processor_state();
216 error = swsusp_arch_suspend();
218 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
220 /* Restore control flow magically appears here */
221 restore_processor_state();
223 platform_leave(platform_mode);
225 /* NOTE: device_power_up() is just a resume() for devices
226 * that suspended with irqs off ... no overall powerup.
228 device_power_up(in_suspend ?
229 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
237 * hibernation_snapshot - quiesce devices and create the hibernation
239 * @platform_mode - if set, use the platform driver, if available, to
240 * prepare the platform frimware for the power transition.
242 * Must be called with pm_mutex held
245 int hibernation_snapshot(int platform_mode)
249 /* Free memory before shutting down devices. */
250 error = swsusp_shrink_memory();
254 error = platform_begin(platform_mode);
259 error = device_suspend(PMSG_FREEZE);
263 if (hibernation_test(TEST_DEVICES))
266 error = platform_pre_snapshot(platform_mode);
267 if (error || hibernation_test(TEST_PLATFORM))
270 error = disable_nonboot_cpus();
272 if (hibernation_test(TEST_CPUS))
275 if (hibernation_testmode(HIBERNATION_TEST))
278 error = create_image(platform_mode);
279 /* Control returns here after successful restore */
282 enable_nonboot_cpus();
284 platform_finish(platform_mode);
286 device_resume(in_suspend ?
287 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
291 platform_end(platform_mode);
296 * resume_target_kernel - prepare devices that need to be suspended with
297 * interrupts off, restore the contents of highmem that have not been
298 * restored yet from the image and run the low level code that will restore
299 * the remaining contents of memory and switch to the just restored target
303 static int resume_target_kernel(void)
309 error = device_power_down(PMSG_QUIESCE);
311 printk(KERN_ERR "PM: Some devices failed to power down, "
312 "aborting resume\n");
315 /* We'll ignore saved state, but this gets preempt count (etc) right */
316 save_processor_state();
317 error = restore_highmem();
319 error = swsusp_arch_resume();
321 * The code below is only ever reached in case of a failure.
322 * Otherwise execution continues at place where
323 * swsusp_arch_suspend() was called
326 /* This call to restore_highmem() undos the previous one */
330 * The only reason why swsusp_arch_resume() can fail is memory being
331 * very tight, so we have to free it as soon as we can to avoid
332 * subsequent failures
335 restore_processor_state();
336 touch_softlockup_watchdog();
337 device_power_up(PMSG_RECOVER);
345 * hibernation_restore - quiesce devices and restore the hibernation
346 * snapshot image. If successful, control returns in hibernation_snaphot()
347 * @platform_mode - if set, use the platform driver, if available, to
348 * prepare the platform frimware for the transition.
350 * Must be called with pm_mutex held
353 int hibernation_restore(int platform_mode)
357 pm_prepare_console();
359 error = device_suspend(PMSG_QUIESCE);
363 error = platform_pre_restore(platform_mode);
365 error = disable_nonboot_cpus();
367 error = resume_target_kernel();
368 enable_nonboot_cpus();
370 platform_restore_cleanup(platform_mode);
371 device_resume(PMSG_RECOVER);
374 pm_restore_console();
379 * hibernation_platform_enter - enter the hibernation state using the
380 * platform driver (if available)
383 int hibernation_platform_enter(void)
387 if (!hibernation_ops)
391 * We have cancelled the power transition by running
392 * hibernation_ops->finish() before saving the image, so we should let
393 * the firmware know that we're going to enter the sleep state after all
395 error = hibernation_ops->begin();
400 error = device_suspend(PMSG_HIBERNATE);
404 error = hibernation_ops->prepare();
408 error = disable_nonboot_cpus();
414 error = device_power_down(PMSG_HIBERNATE);
416 hibernation_ops->enter();
417 /* We should never get here */
424 * We don't need to reenable the nonboot CPUs or resume consoles, since
425 * the system is going to be halted anyway.
428 hibernation_ops->finish();
430 device_resume(PMSG_RESTORE);
434 hibernation_ops->end();
439 * power_down - Shut the machine down for hibernation.
441 * Use the platform driver, if configured so; otherwise try
442 * to power off or reboot.
445 static void power_down(void)
447 switch (hibernation_mode) {
448 case HIBERNATION_TEST:
449 case HIBERNATION_TESTPROC:
451 case HIBERNATION_REBOOT:
452 kernel_restart(NULL);
454 case HIBERNATION_PLATFORM:
455 hibernation_platform_enter();
456 case HIBERNATION_SHUTDOWN:
462 * Valid image is on the disk, if we continue we risk serious data
463 * corruption after resume.
465 printk(KERN_CRIT "PM: Please power down manually\n");
469 static int prepare_processes(void)
473 if (freeze_processes()) {
481 * hibernate - The granpappy of the built-in hibernation management
488 mutex_lock(&pm_mutex);
489 /* The snapshot device should not be opened while we're running */
490 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
495 pm_prepare_console();
496 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
500 /* Allocate memory management structures */
501 error = create_basic_memory_bitmaps();
505 printk(KERN_INFO "PM: Syncing filesystems ... ");
509 error = prepare_processes();
513 if (hibernation_test(TEST_FREEZER))
516 if (hibernation_testmode(HIBERNATION_TESTPROC))
519 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
520 if (in_suspend && !error) {
521 unsigned int flags = 0;
523 if (hibernation_mode == HIBERNATION_PLATFORM)
524 flags |= SF_PLATFORM_MODE;
525 pr_debug("PM: writing image.\n");
526 error = swsusp_write(flags);
531 pr_debug("PM: Image restored successfully.\n");
537 free_basic_memory_bitmaps();
539 pm_notifier_call_chain(PM_POST_HIBERNATION);
540 pm_restore_console();
541 atomic_inc(&snapshot_device_available);
543 mutex_unlock(&pm_mutex);
549 * software_resume - Resume from a saved image.
551 * Called as a late_initcall (so all devices are discovered and
552 * initialized), we call swsusp to see if we have a saved image or not.
553 * If so, we quiesce devices, the restore the saved image. We will
554 * return above (in hibernate() ) if everything goes well.
555 * Otherwise, we fail gracefully and return to the normally
560 static int software_resume(void)
566 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
567 * is configured into the kernel. Since the regular hibernate
568 * trigger path is via sysfs which takes a buffer mutex before
569 * calling hibernate functions (which take pm_mutex) this can
570 * cause lockdep to complain about a possible ABBA deadlock
571 * which cannot happen since we're in the boot code here and
572 * sysfs can't be invoked yet. Therefore, we use a subclass
573 * here to avoid lockdep complaining.
575 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
576 if (!swsusp_resume_device) {
577 if (!strlen(resume_file)) {
578 mutex_unlock(&pm_mutex);
581 swsusp_resume_device = name_to_dev_t(resume_file);
582 pr_debug("PM: Resume from partition %s\n", resume_file);
584 pr_debug("PM: Resume from partition %d:%d\n",
585 MAJOR(swsusp_resume_device),
586 MINOR(swsusp_resume_device));
591 * FIXME: If noresume is specified, we need to find the
592 * partition and reset it back to normal swap space.
594 mutex_unlock(&pm_mutex);
598 pr_debug("PM: Checking hibernation image.\n");
599 error = swsusp_check();
603 /* The snapshot device should not be opened while we're running */
604 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
609 pm_prepare_console();
610 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
614 error = create_basic_memory_bitmaps();
618 pr_debug("PM: Preparing processes for restore.\n");
619 error = prepare_processes();
625 pr_debug("PM: Reading hibernation image.\n");
627 error = swsusp_read(&flags);
629 hibernation_restore(flags & SF_PLATFORM_MODE);
631 printk(KERN_ERR "PM: Restore failed, recovering.\n");
635 free_basic_memory_bitmaps();
637 pm_notifier_call_chain(PM_POST_RESTORE);
638 pm_restore_console();
639 atomic_inc(&snapshot_device_available);
640 /* For success case, the suspend path will release the lock */
642 mutex_unlock(&pm_mutex);
643 pr_debug("PM: Resume from disk failed.\n");
647 late_initcall(software_resume);
650 static const char * const hibernation_modes[] = {
651 [HIBERNATION_PLATFORM] = "platform",
652 [HIBERNATION_SHUTDOWN] = "shutdown",
653 [HIBERNATION_REBOOT] = "reboot",
654 [HIBERNATION_TEST] = "test",
655 [HIBERNATION_TESTPROC] = "testproc",
659 * disk - Control hibernation mode
661 * Suspend-to-disk can be handled in several ways. We have a few options
662 * for putting the system to sleep - using the platform driver (e.g. ACPI
663 * or other hibernation_ops), powering off the system or rebooting the
664 * system (for testing) as well as the two test modes.
666 * The system can support 'platform', and that is known a priori (and
667 * encoded by the presence of hibernation_ops). However, the user may
668 * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
669 * test modes, 'test' or 'testproc'.
671 * show() will display what the mode is currently set to.
672 * store() will accept one of
680 * It will only change to 'platform' if the system
681 * supports it (as determined by having hibernation_ops).
684 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
690 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
691 if (!hibernation_modes[i])
694 case HIBERNATION_SHUTDOWN:
695 case HIBERNATION_REBOOT:
696 case HIBERNATION_TEST:
697 case HIBERNATION_TESTPROC:
699 case HIBERNATION_PLATFORM:
702 /* not a valid mode, continue with loop */
705 if (i == hibernation_mode)
706 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
708 buf += sprintf(buf, "%s ", hibernation_modes[i]);
710 buf += sprintf(buf, "\n");
715 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
716 const char *buf, size_t n)
722 int mode = HIBERNATION_INVALID;
724 p = memchr(buf, '\n', n);
725 len = p ? p - buf : n;
727 mutex_lock(&pm_mutex);
728 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
729 if (len == strlen(hibernation_modes[i])
730 && !strncmp(buf, hibernation_modes[i], len)) {
735 if (mode != HIBERNATION_INVALID) {
737 case HIBERNATION_SHUTDOWN:
738 case HIBERNATION_REBOOT:
739 case HIBERNATION_TEST:
740 case HIBERNATION_TESTPROC:
741 hibernation_mode = mode;
743 case HIBERNATION_PLATFORM:
745 hibernation_mode = mode;
753 pr_debug("PM: Hibernation mode set to '%s'\n",
754 hibernation_modes[mode]);
755 mutex_unlock(&pm_mutex);
756 return error ? error : n;
761 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
764 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
765 MINOR(swsusp_resume_device));
768 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
769 const char *buf, size_t n)
771 unsigned int maj, min;
775 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
778 res = MKDEV(maj,min);
779 if (maj != MAJOR(res) || min != MINOR(res))
782 mutex_lock(&pm_mutex);
783 swsusp_resume_device = res;
784 mutex_unlock(&pm_mutex);
785 printk(KERN_INFO "PM: Starting manual resume from disk\n");
795 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
798 return sprintf(buf, "%lu\n", image_size);
801 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
802 const char *buf, size_t n)
806 if (sscanf(buf, "%lu", &size) == 1) {
814 power_attr(image_size);
816 static struct attribute * g[] = {
819 &image_size_attr.attr,
824 static struct attribute_group attr_group = {
829 static int __init pm_disk_init(void)
831 return sysfs_create_group(power_kobj, &attr_group);
834 core_initcall(pm_disk_init);
837 static int __init resume_setup(char *str)
842 strncpy( resume_file, str, 255 );
846 static int __init resume_offset_setup(char *str)
848 unsigned long long offset;
853 if (sscanf(str, "%llu", &offset) == 1)
854 swsusp_resume_block = offset;
859 static int __init noresume_setup(char *str)
865 __setup("noresume", noresume_setup);
866 __setup("resume_offset=", resume_offset_setup);
867 __setup("resume=", resume_setup);