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 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->start && ops->pre_snapshot && ops->finish
58 && ops->prepare && 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_start - tell the platform driver that we're starting
107 static int platform_start(int platform_mode)
109 return (platform_mode && hibernation_ops) ?
110 hibernation_ops->start() : 0;
114 * platform_pre_snapshot - prepare the machine for hibernation using the
115 * platform driver if so configured and return an error code if it fails
118 static int platform_pre_snapshot(int platform_mode)
120 return (platform_mode && hibernation_ops) ?
121 hibernation_ops->pre_snapshot() : 0;
125 * platform_leave - prepare the machine for switching to the normal mode
126 * of operation using the platform driver (called with interrupts disabled)
129 static void platform_leave(int platform_mode)
131 if (platform_mode && hibernation_ops)
132 hibernation_ops->leave();
136 * platform_finish - switch the machine to the normal mode of operation
137 * using the platform driver (must be called after platform_prepare())
140 static void platform_finish(int platform_mode)
142 if (platform_mode && hibernation_ops)
143 hibernation_ops->finish();
147 * platform_pre_restore - prepare the platform for the restoration from a
148 * hibernation image. If the restore fails after this function has been
149 * called, platform_restore_cleanup() must be called.
152 static int platform_pre_restore(int platform_mode)
154 return (platform_mode && hibernation_ops) ?
155 hibernation_ops->pre_restore() : 0;
159 * platform_restore_cleanup - switch the platform to the normal mode of
160 * operation after a failing restore. If platform_pre_restore() has been
161 * called before the failing restore, this function must be called too,
162 * regardless of the result of platform_pre_restore().
165 static void platform_restore_cleanup(int platform_mode)
167 if (platform_mode && hibernation_ops)
168 hibernation_ops->restore_cleanup();
172 * create_image - freeze devices that need to be frozen with interrupts
173 * off, create the hibernation image and thaw those devices. Control
174 * reappears in this routine after a restore.
177 int create_image(int platform_mode)
181 error = arch_prepare_suspend();
186 /* At this point, device_suspend() has been called, but *not*
187 * device_power_down(). We *must* call device_power_down() now.
188 * Otherwise, drivers for some devices (e.g. interrupt controllers)
189 * become desynchronized with the actual state of the hardware
190 * at resume time, and evil weirdness ensues.
192 error = device_power_down(PMSG_FREEZE);
194 printk(KERN_ERR "Some devices failed to power down, "
195 KERN_ERR "aborting suspend\n");
199 if (hibernation_test(TEST_CORE))
203 save_processor_state();
204 error = swsusp_arch_suspend();
206 printk(KERN_ERR "Error %d while creating the image\n", error);
207 /* Restore control flow magically appears here */
208 restore_processor_state();
210 platform_leave(platform_mode);
212 /* NOTE: device_power_up() is just a resume() for devices
213 * that suspended with irqs off ... no overall powerup.
222 * hibernation_snapshot - quiesce devices and create the hibernation
224 * @platform_mode - if set, use the platform driver, if available, to
225 * prepare the platform frimware for the power transition.
227 * Must be called with pm_mutex held
230 int hibernation_snapshot(int platform_mode)
234 /* Free memory before shutting down devices. */
235 error = swsusp_shrink_memory();
239 error = platform_start(platform_mode);
244 error = device_suspend(PMSG_FREEZE);
248 if (hibernation_test(TEST_DEVICES))
251 error = platform_pre_snapshot(platform_mode);
252 if (error || hibernation_test(TEST_PLATFORM))
255 error = disable_nonboot_cpus();
257 if (hibernation_test(TEST_CPUS))
260 if (hibernation_testmode(HIBERNATION_TEST))
263 error = create_image(platform_mode);
264 /* Control returns here after successful restore */
267 enable_nonboot_cpus();
269 platform_finish(platform_mode);
278 * resume_target_kernel - prepare devices that need to be suspended with
279 * interrupts off, restore the contents of highmem that have not been
280 * restored yet from the image and run the low level code that will restore
281 * the remaining contents of memory and switch to the just restored target
285 static int resume_target_kernel(void)
290 error = device_power_down(PMSG_PRETHAW);
292 printk(KERN_ERR "Some devices failed to power down, "
293 "aborting resume\n");
296 /* We'll ignore saved state, but this gets preempt count (etc) right */
297 save_processor_state();
298 error = restore_highmem();
300 error = swsusp_arch_resume();
302 * The code below is only ever reached in case of a failure.
303 * Otherwise execution continues at place where
304 * swsusp_arch_suspend() was called
307 /* This call to restore_highmem() undos the previous one */
311 * The only reason why swsusp_arch_resume() can fail is memory being
312 * very tight, so we have to free it as soon as we can to avoid
313 * subsequent failures
316 restore_processor_state();
317 touch_softlockup_watchdog();
325 * hibernation_restore - quiesce devices and restore the hibernation
326 * snapshot image. If successful, control returns in hibernation_snaphot()
327 * @platform_mode - if set, use the platform driver, if available, to
328 * prepare the platform frimware for the transition.
330 * Must be called with pm_mutex held
333 int hibernation_restore(int platform_mode)
337 pm_prepare_console();
339 error = device_suspend(PMSG_PRETHAW);
343 error = platform_pre_restore(platform_mode);
345 error = disable_nonboot_cpus();
347 error = resume_target_kernel();
348 enable_nonboot_cpus();
350 platform_restore_cleanup(platform_mode);
354 pm_restore_console();
359 * hibernation_platform_enter - enter the hibernation state using the
360 * platform driver (if available)
363 int hibernation_platform_enter(void)
367 if (!hibernation_ops)
371 * We have cancelled the power transition by running
372 * hibernation_ops->finish() before saving the image, so we should let
373 * the firmware know that we're going to enter the sleep state after all
375 error = hibernation_ops->start();
380 error = device_suspend(PMSG_SUSPEND);
384 error = hibernation_ops->prepare();
388 error = disable_nonboot_cpus();
393 error = device_power_down(PMSG_SUSPEND);
395 hibernation_ops->enter();
396 /* We should never get here */
402 * We don't need to reenable the nonboot CPUs or resume consoles, since
403 * the system is going to be halted anyway.
406 hibernation_ops->finish();
415 * power_down - Shut the machine down for hibernation.
417 * Use the platform driver, if configured so; otherwise try
418 * to power off or reboot.
421 static void power_down(void)
423 switch (hibernation_mode) {
424 case HIBERNATION_TEST:
425 case HIBERNATION_TESTPROC:
427 case HIBERNATION_REBOOT:
428 kernel_restart(NULL);
430 case HIBERNATION_PLATFORM:
431 hibernation_platform_enter();
432 case HIBERNATION_SHUTDOWN:
438 * Valid image is on the disk, if we continue we risk serious data
439 * corruption after resume.
441 printk(KERN_CRIT "Please power me down manually\n");
445 static void unprepare_processes(void)
448 pm_restore_console();
451 static int prepare_processes(void)
455 pm_prepare_console();
456 if (freeze_processes()) {
458 unprepare_processes();
464 * hibernate - The granpappy of the built-in hibernation management
471 mutex_lock(&pm_mutex);
472 /* The snapshot device should not be opened while we're running */
473 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
478 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
482 /* Allocate memory management structures */
483 error = create_basic_memory_bitmaps();
487 printk("Syncing filesystems ... ");
491 error = prepare_processes();
495 if (hibernation_test(TEST_FREEZER))
498 if (hibernation_testmode(HIBERNATION_TESTPROC))
501 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
502 if (in_suspend && !error) {
503 unsigned int flags = 0;
505 if (hibernation_mode == HIBERNATION_PLATFORM)
506 flags |= SF_PLATFORM_MODE;
507 pr_debug("PM: writing image.\n");
508 error = swsusp_write(flags);
513 pr_debug("PM: Image restored successfully.\n");
517 unprepare_processes();
519 free_basic_memory_bitmaps();
521 pm_notifier_call_chain(PM_POST_HIBERNATION);
522 atomic_inc(&snapshot_device_available);
524 mutex_unlock(&pm_mutex);
530 * software_resume - Resume from a saved image.
532 * Called as a late_initcall (so all devices are discovered and
533 * initialized), we call swsusp to see if we have a saved image or not.
534 * If so, we quiesce devices, the restore the saved image. We will
535 * return above (in hibernate() ) if everything goes well.
536 * Otherwise, we fail gracefully and return to the normally
541 static int software_resume(void)
547 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
548 * is configured into the kernel. Since the regular hibernate
549 * trigger path is via sysfs which takes a buffer mutex before
550 * calling hibernate functions (which take pm_mutex) this can
551 * cause lockdep to complain about a possible ABBA deadlock
552 * which cannot happen since we're in the boot code here and
553 * sysfs can't be invoked yet. Therefore, we use a subclass
554 * here to avoid lockdep complaining.
556 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
557 if (!swsusp_resume_device) {
558 if (!strlen(resume_file)) {
559 mutex_unlock(&pm_mutex);
562 swsusp_resume_device = name_to_dev_t(resume_file);
563 pr_debug("swsusp: Resume From Partition %s\n", resume_file);
565 pr_debug("swsusp: Resume From Partition %d:%d\n",
566 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
571 * FIXME: If noresume is specified, we need to find the partition
572 * and reset it back to normal swap space.
574 mutex_unlock(&pm_mutex);
578 pr_debug("PM: Checking swsusp image.\n");
579 error = swsusp_check();
583 /* The snapshot device should not be opened while we're running */
584 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
589 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
593 error = create_basic_memory_bitmaps();
597 pr_debug("PM: Preparing processes for restore.\n");
598 error = prepare_processes();
604 pr_debug("PM: Reading swsusp image.\n");
606 error = swsusp_read(&flags);
608 hibernation_restore(flags & SF_PLATFORM_MODE);
610 printk(KERN_ERR "PM: Restore failed, recovering.\n");
612 unprepare_processes();
614 free_basic_memory_bitmaps();
616 pm_notifier_call_chain(PM_POST_RESTORE);
617 atomic_inc(&snapshot_device_available);
618 /* For success case, the suspend path will release the lock */
620 mutex_unlock(&pm_mutex);
621 pr_debug("PM: Resume from disk failed.\n");
625 late_initcall(software_resume);
628 static const char * const hibernation_modes[] = {
629 [HIBERNATION_PLATFORM] = "platform",
630 [HIBERNATION_SHUTDOWN] = "shutdown",
631 [HIBERNATION_REBOOT] = "reboot",
632 [HIBERNATION_TEST] = "test",
633 [HIBERNATION_TESTPROC] = "testproc",
637 * disk - Control hibernation mode
639 * Suspend-to-disk can be handled in several ways. We have a few options
640 * for putting the system to sleep - using the platform driver (e.g. ACPI
641 * or other hibernation_ops), powering off the system or rebooting the
642 * system (for testing) as well as the two test modes.
644 * The system can support 'platform', and that is known a priori (and
645 * encoded by the presence of hibernation_ops). However, the user may
646 * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
647 * test modes, 'test' or 'testproc'.
649 * show() will display what the mode is currently set to.
650 * store() will accept one of
658 * It will only change to 'platform' if the system
659 * supports it (as determined by having hibernation_ops).
662 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
668 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
669 if (!hibernation_modes[i])
672 case HIBERNATION_SHUTDOWN:
673 case HIBERNATION_REBOOT:
674 case HIBERNATION_TEST:
675 case HIBERNATION_TESTPROC:
677 case HIBERNATION_PLATFORM:
680 /* not a valid mode, continue with loop */
683 if (i == hibernation_mode)
684 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
686 buf += sprintf(buf, "%s ", hibernation_modes[i]);
688 buf += sprintf(buf, "\n");
693 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
694 const char *buf, size_t n)
700 int mode = HIBERNATION_INVALID;
702 p = memchr(buf, '\n', n);
703 len = p ? p - buf : n;
705 mutex_lock(&pm_mutex);
706 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
707 if (len == strlen(hibernation_modes[i])
708 && !strncmp(buf, hibernation_modes[i], len)) {
713 if (mode != HIBERNATION_INVALID) {
715 case HIBERNATION_SHUTDOWN:
716 case HIBERNATION_REBOOT:
717 case HIBERNATION_TEST:
718 case HIBERNATION_TESTPROC:
719 hibernation_mode = mode;
721 case HIBERNATION_PLATFORM:
723 hibernation_mode = mode;
731 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
732 hibernation_modes[mode]);
733 mutex_unlock(&pm_mutex);
734 return error ? error : n;
739 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
742 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
743 MINOR(swsusp_resume_device));
746 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
747 const char *buf, size_t n)
749 unsigned int maj, min;
753 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
756 res = MKDEV(maj,min);
757 if (maj != MAJOR(res) || min != MINOR(res))
760 mutex_lock(&pm_mutex);
761 swsusp_resume_device = res;
762 mutex_unlock(&pm_mutex);
763 printk("Attempting manual resume\n");
773 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
776 return sprintf(buf, "%lu\n", image_size);
779 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
780 const char *buf, size_t n)
784 if (sscanf(buf, "%lu", &size) == 1) {
792 power_attr(image_size);
794 static struct attribute * g[] = {
797 &image_size_attr.attr,
802 static struct attribute_group attr_group = {
807 static int __init pm_disk_init(void)
809 return sysfs_create_group(power_kobj, &attr_group);
812 core_initcall(pm_disk_init);
815 static int __init resume_setup(char *str)
820 strncpy( resume_file, str, 255 );
824 static int __init resume_offset_setup(char *str)
826 unsigned long long offset;
831 if (sscanf(str, "%llu", &offset) == 1)
832 swsusp_resume_block = offset;
837 static int __init noresume_setup(char *str)
843 __setup("noresume", noresume_setup);
844 __setup("resume_offset=", resume_offset_setup);
845 __setup("resume=", resume_setup);