/* * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support. * * Copyright (c) 2003 Patrick Mochel * Copyright (c) 2003 Open Source Development Lab * Copyright (c) 2004 Pavel Machek * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc. * * This file is released under the GPLv2. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "power.h" static int nocompress; static int noresume; static int resume_wait; static int resume_delay; static char resume_file[256] = CONFIG_PM_STD_PARTITION; dev_t swsusp_resume_device; sector_t swsusp_resume_block; int in_suspend __nosavedata; enum { HIBERNATION_INVALID, HIBERNATION_PLATFORM, HIBERNATION_SHUTDOWN, HIBERNATION_REBOOT, /* keep last */ __HIBERNATION_AFTER_LAST }; #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1) #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1) static int hibernation_mode = HIBERNATION_SHUTDOWN; bool freezer_test_done; static const struct platform_hibernation_ops *hibernation_ops; /** * hibernation_set_ops - Set the global hibernate operations. * @ops: Hibernation operations to use in subsequent hibernation transitions. */ void hibernation_set_ops(const struct platform_hibernation_ops *ops) { if (ops && !(ops->begin && ops->end && ops->pre_snapshot && ops->prepare && ops->finish && ops->enter && ops->pre_restore && ops->restore_cleanup && ops->leave)) { WARN_ON(1); return; } lock_system_sleep(); hibernation_ops = ops; if (ops) hibernation_mode = HIBERNATION_PLATFORM; else if (hibernation_mode == HIBERNATION_PLATFORM) hibernation_mode = HIBERNATION_SHUTDOWN; unlock_system_sleep(); } static bool entering_platform_hibernation; bool system_entering_hibernation(void) { return entering_platform_hibernation; } EXPORT_SYMBOL(system_entering_hibernation); #ifdef CONFIG_PM_DEBUG static void hibernation_debug_sleep(void) { printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n"); mdelay(5000); } static int hibernation_test(int level) { if (pm_test_level == level) { hibernation_debug_sleep(); return 1; } return 0; } #else /* !CONFIG_PM_DEBUG */ static int hibernation_test(int level) { return 0; } #endif /* !CONFIG_PM_DEBUG */ /** * platform_begin - Call platform to start hibernation. * @platform_mode: Whether or not to use the platform driver. */ static int platform_begin(int platform_mode) { return (platform_mode && hibernation_ops) ? hibernation_ops->begin() : 0; } /** * platform_end - Call platform to finish transition to the working state. * @platform_mode: Whether or not to use the platform driver. */ static void platform_end(int platform_mode) { if (platform_mode && hibernation_ops) hibernation_ops->end(); } /** * platform_pre_snapshot - Call platform to prepare the machine for hibernation. * @platform_mode: Whether or not to use the platform driver. * * Use the platform driver to prepare the system for creating a hibernate image, * if so configured, and return an error code if that fails. */ static int platform_pre_snapshot(int platform_mode) { return (platform_mode && hibernation_ops) ? hibernation_ops->pre_snapshot() : 0; } /** * platform_leave - Call platform to prepare a transition to the working state. * @platform_mode: Whether or not to use the platform driver. * * Use the platform driver prepare to prepare the machine for switching to the * normal mode of operation. * * This routine is called on one CPU with interrupts disabled. */ static void platform_leave(int platform_mode) { if (platform_mode && hibernation_ops) hibernation_ops->leave(); } /** * platform_finish - Call platform to switch the system to the working state. * @platform_mode: Whether or not to use the platform driver. * * Use the platform driver to switch the machine to the normal mode of * operation. * * This routine must be called after platform_prepare(). */ static void platform_finish(int platform_mode) { if (platform_mode && hibernation_ops) hibernation_ops->finish(); } /** * platform_pre_restore - Prepare for hibernate image restoration. * @platform_mode: Whether or not to use the platform driver. * * Use the platform driver to prepare the system for resume from a hibernation * image. * * If the restore fails after this function has been called, * platform_restore_cleanup() must be called. */ static int platform_pre_restore(int platform_mode) { return (platform_mode && hibernation_ops) ? hibernation_ops->pre_restore() : 0; } /** * platform_restore_cleanup - Switch to the working state after failing restore. * @platform_mode: Whether or not to use the platform driver. * * Use the platform driver to switch the system to the normal mode of operation * after a failing restore. * * If platform_pre_restore() has been called before the failing restore, this * function must be called too, regardless of the result of * platform_pre_restore(). */ static void platform_restore_cleanup(int platform_mode) { if (platform_mode && hibernation_ops) hibernation_ops->restore_cleanup(); } /** * platform_recover - Recover from a failure to suspend devices. * @platform_mode: Whether or not to use the platform driver. */ static void platform_recover(int platform_mode) { if (platform_mode && hibernation_ops && hibernation_ops->recover) hibernation_ops->recover(); } /** * swsusp_show_speed - Print time elapsed between two events during hibernation. * @start: Starting event. * @stop: Final event. * @nr_pages: Number of memory pages processed between @start and @stop. * @msg: Additional diagnostic message to print. */ void swsusp_show_speed(struct timeval *start, struct timeval *stop, unsigned nr_pages, char *msg) { s64 elapsed_centisecs64; int centisecs; int k; int kps; elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start); do_div(elapsed_centisecs64, NSEC_PER_SEC / 100); centisecs = elapsed_centisecs64; if (centisecs == 0) centisecs = 1; /* avoid div-by-zero */ k = nr_pages * (PAGE_SIZE / 1024); kps = (k * 100) / centisecs; printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n", msg, k, centisecs / 100, centisecs % 100, kps / 1000, (kps % 1000) / 10); } /** * create_image - Create a hibernation image. * @platform_mode: Whether or not to use the platform driver. * * Execute device drivers' "late" and "noirq" freeze callbacks, create a * hibernation image and run the drivers' "noirq" and "early" thaw callbacks. * * Control reappears in this routine after the subsequent restore. */ static int create_image(int platform_mode) { int error; error = dpm_suspend_end(PMSG_FREEZE); if (error) { printk(KERN_ERR "PM: Some devices failed to power down, " "aborting hibernation\n"); return error; } error = platform_pre_snapshot(platform_mode); if (error || hibernation_test(TEST_PLATFORM)) goto Platform_finish; error = disable_nonboot_cpus(); if (error || hibernation_test(TEST_CPUS)) goto Enable_cpus; local_irq_disable(); error = syscore_suspend(); if (error) { printk(KERN_ERR "PM: Some system devices failed to power down, " "aborting hibernation\n"); goto Enable_irqs; } if (hibernation_test(TEST_CORE) || pm_wakeup_pending()) goto Power_up; in_suspend = 1; save_processor_state(); error = swsusp_arch_suspend(); if (error) printk(KERN_ERR "PM: Error %d creating hibernation image\n", error); /* Restore control flow magically appears here */ restore_processor_state(); if (!in_suspend) { events_check_enabled = false; platform_leave(platform_mode); } Power_up: syscore_resume(); Enable_irqs: local_irq_enable(); Enable_cpus: enable_nonboot_cpus(); Platform_finish: platform_finish(platform_mode); dpm_resume_start(in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); return error; } /** * hibernation_snapshot - Quiesce devices and create a hibernation image. * @platform_mode: If set, use platform driver to prepare for the transition. * * This routine must be called with pm_mutex held. */ int hibernation_snapshot(int platform_mode) { pm_message_t msg; int error; error = platform_begin(platform_mode); if (error) goto Close; /* Preallocate image memory before shutting down devices. */ error = hibernate_preallocate_memory(); if (error) goto Close; error = freeze_kernel_threads(); if (error) goto Cleanup; if (hibernation_test(TEST_FREEZER)) { /* * Indicate to the caller that we are returning due to a * successful freezer test. */ freezer_test_done = true; goto Thaw; } error = dpm_prepare(PMSG_FREEZE); if (error) { dpm_complete(PMSG_RECOVER); goto Thaw; } suspend_console(); pm_restrict_gfp_mask(); error = dpm_suspend(PMSG_FREEZE); if (error || hibernation_test(TEST_DEVICES)) platform_recover(platform_mode); else error = create_image(platform_mode); /* * In the case that we call create_image() above, the control * returns here (1) after the image has been created or the * image creation has failed and (2) after a successful restore. */ /* We may need to release the preallocated image pages here. */ if (error || !in_suspend) swsusp_free(); msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE; dpm_resume(msg); if (error || !in_suspend) pm_restore_gfp_mask(); resume_console(); dpm_complete(msg); Close: platform_end(platform_mode); return error; Thaw: thaw_kernel_threads(); Cleanup: swsusp_free(); goto Close; } /** * resume_target_kernel - Restore system state from a hibernation image. * @platform_mode: Whether or not to use the platform driver. * * Execute device drivers' "noirq" and "late" freeze callbacks, restore the * contents of highmem that have not been restored yet from the image and run * the low-level code that will restore the remaining contents of memory and * switch to the just restored target kernel. */ static int resume_target_kernel(bool platform_mode) { int error; error = dpm_suspend_end(PMSG_QUIESCE); if (error) { printk(KERN_ERR "PM: Some devices failed to power down, " "aborting resume\n"); return error; } error = platform_pre_restore(platform_mode); if (error) goto Cleanup; error = disable_nonboot_cpus(); if (error) goto Enable_cpus; local_irq_disable(); error = syscore_suspend(); if (error) goto Enable_irqs; save_processor_state(); error = restore_highmem(); if (!error) { error = swsusp_arch_resume(); /* * The code below is only ever reached in case of a failure. * Otherwise, execution continues at the place where * swsusp_arch_suspend() was called. */ BUG_ON(!error); /* * This call to restore_highmem() reverts the changes made by * the previous one. */ restore_highmem(); } /* * The only reason why swsusp_arch_resume() can fail is memory being * very tight, so we have to free it as soon as we can to avoid * subsequent failures. */ swsusp_free(); restore_processor_state(); touch_softlockup_watchdog(); syscore_resume(); Enable_irqs: local_irq_enable(); Enable_cpus: enable_nonboot_cpus(); Cleanup: platform_restore_cleanup(platform_mode); dpm_resume_start(PMSG_RECOVER); return error; } /** * hibernation_restore - Quiesce devices and restore from a hibernation image. * @platform_mode: If set, use platform driver to prepare for the transition. * * This routine must be called with pm_mutex held. If it is successful, control * reappears in the restored target kernel in hibernation_snapshot(). */ int hibernation_restore(int platform_mode) { int error; pm_prepare_console(); suspend_console(); pm_restrict_gfp_mask(); error = dpm_suspend_start(PMSG_QUIESCE); if (!error) { error = resume_target_kernel(platform_mode); dpm_resume_end(PMSG_RECOVER); } pm_restore_gfp_mask(); resume_console(); pm_restore_console(); return error; } /** * hibernation_platform_enter - Power off the system using the platform driver. */ int hibernation_platform_enter(void) { int error; if (!hibernation_ops) return -ENOSYS; /* * We have cancelled the power transition by running * hibernation_ops->finish() before saving the image, so we should let * the firmware know that we're going to enter the sleep state after all */ error = hibernation_ops->begin(); if (error) goto Close; entering_platform_hibernation = true; suspend_console(); error = dpm_suspend_start(PMSG_HIBERNATE); if (error) { if (hibernation_ops->recover) hibernation_ops->recover(); goto Resume_devices; } error = dpm_suspend_end(PMSG_HIBERNATE); if (error) goto Resume_devices; error = hibernation_ops->prepare(); if (error) goto Platform_finish; error = disable_nonboot_cpus(); if (error) goto Platform_finish; local_irq_disable(); syscore_suspend(); if (pm_wakeup_pending()) { error = -EAGAIN; goto Power_up; } hibernation_ops->enter(); /* We should never get here */ while (1); Power_up: syscore_resume(); local_irq_enable(); enable_nonboot_cpus(); Platform_finish: hibernation_ops->finish(); dpm_resume_start(PMSG_RESTORE); Resume_devices: entering_platform_hibernation = false; dpm_resume_end(PMSG_RESTORE); resume_console(); Close: hibernation_ops->end(); return error; } /** * power_down - Shut the machine down for hibernation. * * Use the platform driver, if configured, to put the system into the sleep * state corresponding to hibernation, or try to power it off or reboot, * depending on the value of hibernation_mode. */ static void power_down(void) { switch (hibernation_mode) { case HIBERNATION_REBOOT: kernel_restart(NULL); break; case HIBERNATION_PLATFORM: hibernation_platform_enter(); case HIBERNATION_SHUTDOWN: kernel_power_off(); break; } kernel_halt(); /* * Valid image is on the disk, if we continue we risk serious data * corruption after resume. */ printk(KERN_CRIT "PM: Please power down manually\n"); while(1); } /** * hibernate - Carry out system hibernation, including saving the image. */ int hibernate(void) { int error; lock_system_sleep(); /* The snapshot device should not be opened while we're running */ if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { error = -EBUSY; goto Unlock; } pm_prepare_console(); error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE); if (error) goto Exit; error = usermodehelper_disable(); if (error) goto Exit; /* Allocate memory management structures */ error = create_basic_memory_bitmaps(); if (error) goto Exit; printk(KERN_INFO "PM: Syncing filesystems ... "); sys_sync(); printk("done.\n"); error = freeze_processes(); if (error) goto Finish; error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM); if (error) goto Thaw; if (freezer_test_done) { freezer_test_done = false; goto Thaw; } if (in_suspend) { unsigned int flags = 0; if (hibernation_mode == HIBERNATION_PLATFORM) flags |= SF_PLATFORM_MODE; if (nocompress) flags |= SF_NOCOMPRESS_MODE; else flags |= SF_CRC32_MODE; pr_debug("PM: writing image.\n"); error = swsusp_write(flags); swsusp_free(); if (!error) power_down(); in_suspend = 0; pm_restore_gfp_mask(); } else { pr_debug("PM: Image restored successfully.\n"); } Thaw: thaw_processes(); Finish: free_basic_memory_bitmaps(); usermodehelper_enable(); Exit: pm_notifier_call_chain(PM_POST_HIBERNATION); pm_restore_console(); atomic_inc(&snapshot_device_available); Unlock: unlock_system_sleep(); return error; } /** * software_resume - Resume from a saved hibernation image. * * This routine is called as a late initcall, when all devices have been * discovered and initialized already. * * The image reading code is called to see if there is a hibernation image * available for reading. If that is the case, devices are quiesced and the * contents of memory is restored from the saved image. * * If this is successful, control reappears in the restored target kernel in * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine * attempts to recover gracefully and make the kernel return to the normal mode * of operation. */ static int software_resume(void) { int error; unsigned int flags; /* * If the user said "noresume".. bail out early. */ if (noresume) return 0; /* * name_to_dev_t() below takes a sysfs buffer mutex when sysfs * is configured into the kernel. Since the regular hibernate * trigger path is via sysfs which takes a buffer mutex before * calling hibernate functions (which take pm_mutex) this can * cause lockdep to complain about a possible ABBA deadlock * which cannot happen since we're in the boot code here and * sysfs can't be invoked yet. Therefore, we use a subclass * here to avoid lockdep complaining. */ mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING); if (swsusp_resume_device) goto Check_image; if (!strlen(resume_file)) { error = -ENOENT; goto Unlock; } pr_debug("PM: Checking hibernation image partition %s\n", resume_file); if (resume_delay) { printk(KERN_INFO "Waiting %dsec before reading resume device...\n", resume_delay); ssleep(resume_delay); } /* Check if the device is there */ swsusp_resume_device = name_to_dev_t(resume_file); if (!swsusp_resume_device) { /* * Some device discovery might still be in progress; we need * to wait for this to finish. */ wait_for_device_probe(); if (resume_wait) { while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0) msleep(10); async_synchronize_full(); } /* * We can't depend on SCSI devices being available after loading * one of their modules until scsi_complete_async_scans() is * called and the resume device usually is a SCSI one. */ scsi_complete_async_scans(); swsusp_resume_device = name_to_dev_t(resume_file); if (!swsusp_resume_device) { error = -ENODEV; goto Unlock; } } Check_image: pr_debug("PM: Hibernation image partition %d:%d present\n", MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device)); pr_debug("PM: Looking for hibernation image.\n"); error = swsusp_check(); if (error) goto Unlock; /* The snapshot device should not be opened while we're running */ if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { error = -EBUSY; swsusp_close(FMODE_READ); goto Unlock; } pm_prepare_console(); error = pm_notifier_call_chain(PM_RESTORE_PREPARE); if (error) goto close_finish; error = usermodehelper_disable(); if (error) goto close_finish; error = create_basic_memory_bitmaps(); if (error) { usermodehelper_enable(); goto close_finish; } pr_debug("PM: Preparing processes for restore.\n"); error = freeze_processes(); if (error) { swsusp_close(FMODE_READ); goto Done; } pr_debug("PM: Loading hibernation image.\n"); error = swsusp_read(&flags); swsusp_close(FMODE_READ); if (!error) hibernation_restore(flags & SF_PLATFORM_MODE); printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n"); swsusp_free(); thaw_processes(); Done: free_basic_memory_bitmaps(); usermodehelper_enable(); Finish: pm_notifier_call_chain(PM_POST_RESTORE); pm_restore_console(); atomic_inc(&snapshot_device_available); /* For success case, the suspend path will release the lock */ Unlock: mutex_unlock(&pm_mutex); pr_debug("PM: Hibernation image not present or could not be loaded.\n"); return error; close_finish: swsusp_close(FMODE_READ); goto Finish; } late_initcall(software_resume); static const char * const hibernation_modes[] = { [HIBERNATION_PLATFORM] = "platform", [HIBERNATION_SHUTDOWN] = "shutdown", [HIBERNATION_REBOOT] = "reboot", }; /* * /sys/power/disk - Control hibernation mode. * * Hibernation can be handled in several ways. There are a few different ways * to put the system into the sleep state: using the platform driver (e.g. ACPI * or other hibernation_ops), powering it off or rebooting it (for testing * mostly). * * The sysfs file /sys/power/disk provides an interface for selecting the * hibernation mode to use. Reading from this file causes the available modes * to be printed. There are 3 modes that can be supported: * * 'platform' * 'shutdown' * 'reboot' * * If a platform hibernation driver is in use, 'platform' will be supported * and will be used by default. Otherwise, 'shutdown' will be used by default. * The selected option (i.e. the one corresponding to the current value of * hibernation_mode) is enclosed by a square bracket. * * To select a given hibernation mode it is necessary to write the mode's * string representation (as returned by reading from /sys/power/disk) back * into /sys/power/disk. */ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { int i; char *start = buf; for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) { if (!hibernation_modes[i]) continue; switch (i) { case HIBERNATION_SHUTDOWN: case HIBERNATION_REBOOT: break; case HIBERNATION_PLATFORM: if (hibernation_ops) break; /* not a valid mode, continue with loop */ continue; } if (i == hibernation_mode) buf += sprintf(buf, "[%s] ", hibernation_modes[i]); else buf += sprintf(buf, "%s ", hibernation_modes[i]); } buf += sprintf(buf, "\n"); return buf-start; } static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t n) { int error = 0; int i; int len; char *p; int mode = HIBERNATION_INVALID; p = memchr(buf, '\n', n); len = p ? p - buf : n; lock_system_sleep(); for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) { if (len == strlen(hibernation_modes[i]) && !strncmp(buf, hibernation_modes[i], len)) { mode = i; break; } } if (mode != HIBERNATION_INVALID) { switch (mode) { case HIBERNATION_SHUTDOWN: case HIBERNATION_REBOOT: hibernation_mode = mode; break; case HIBERNATION_PLATFORM: if (hibernation_ops) hibernation_mode = mode; else error = -EINVAL; } } else error = -EINVAL; if (!error) pr_debug("PM: Hibernation mode set to '%s'\n", hibernation_modes[mode]); unlock_system_sleep(); return error ? error : n; } power_attr(disk); static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device)); } static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t n) { unsigned int maj, min; dev_t res; int ret = -EINVAL; if (sscanf(buf, "%u:%u", &maj, &min) != 2) goto out; res = MKDEV(maj,min); if (maj != MAJOR(res) || min != MINOR(res)) goto out; lock_system_sleep(); swsusp_resume_device = res; unlock_system_sleep(); printk(KERN_INFO "PM: Starting manual resume from disk\n"); noresume = 0; software_resume(); ret = n; out: return ret; } power_attr(resume); static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%lu\n", image_size); } static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t n) { unsigned long size; if (sscanf(buf, "%lu", &size) == 1) { image_size = size; return n; } return -EINVAL; } power_attr(image_size); static ssize_t reserved_size_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%lu\n", reserved_size); } static ssize_t reserved_size_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t n) { unsigned long size; if (sscanf(buf, "%lu", &size) == 1) { reserved_size = size; return n; } return -EINVAL; } power_attr(reserved_size); static struct attribute * g[] = { &disk_attr.attr, &resume_attr.attr, &image_size_attr.attr, &reserved_size_attr.attr, NULL, }; static struct attribute_group attr_group = { .attrs = g, }; static int __init pm_disk_init(void) { return sysfs_create_group(power_kobj, &attr_group); } core_initcall(pm_disk_init); static int __init resume_setup(char *str) { if (noresume) return 1; strncpy( resume_file, str, 255 ); return 1; } static int __init resume_offset_setup(char *str) { unsigned long long offset; if (noresume) return 1; if (sscanf(str, "%llu", &offset) == 1) swsusp_resume_block = offset; return 1; } static int __init hibernate_setup(char *str) { if (!strncmp(str, "noresume", 8)) noresume = 1; else if (!strncmp(str, "nocompress", 10)) nocompress = 1; return 1; } static int __init noresume_setup(char *str) { noresume = 1; return 1; } static int __init resumewait_setup(char *str) { resume_wait = 1; return 1; } static int __init resumedelay_setup(char *str) { resume_delay = simple_strtoul(str, NULL, 0); return 1; } __setup("noresume", noresume_setup); __setup("resume_offset=", resume_offset_setup); __setup("resume=", resume_setup); __setup("hibernate=", hibernate_setup); __setup("resumewait", resumewait_setup); __setup("resumedelay=", resumedelay_setup);