diff options
Diffstat (limited to 'kernel/power/hibernate.c')
| -rw-r--r-- | kernel/power/hibernate.c | 955 |
1 files changed, 955 insertions, 0 deletions
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c new file mode 100644 index 00000000000..81d2e746489 --- /dev/null +++ b/kernel/power/hibernate.c @@ -0,0 +1,955 @@ +/* + * 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 <pavel@suse.cz> + * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc. + * + * This file is released under the GPLv2. + */ + +#include <linux/suspend.h> +#include <linux/syscalls.h> +#include <linux/reboot.h> +#include <linux/string.h> +#include <linux/device.h> +#include <linux/kmod.h> +#include <linux/delay.h> +#include <linux/fs.h> +#include <linux/mount.h> +#include <linux/pm.h> +#include <linux/console.h> +#include <linux/cpu.h> +#include <linux/freezer.h> +#include <scsi/scsi_scan.h> +#include <asm/suspend.h> + +#include "power.h" + + +static int noresume = 0; +static char resume_file[256] = CONFIG_PM_STD_PARTITION; +dev_t swsusp_resume_device; +sector_t swsusp_resume_block; + +enum { + HIBERNATION_INVALID, + HIBERNATION_PLATFORM, + HIBERNATION_TEST, + HIBERNATION_TESTPROC, + 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; + +static struct platform_hibernation_ops *hibernation_ops; + +/** + * hibernation_set_ops - set the global hibernate operations + * @ops: the hibernation operations to use in subsequent hibernation transitions + */ + +void hibernation_set_ops(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)) { + WARN_ON(1); + return; + } + mutex_lock(&pm_mutex); + hibernation_ops = ops; + if (ops) + hibernation_mode = HIBERNATION_PLATFORM; + else if (hibernation_mode == HIBERNATION_PLATFORM) + hibernation_mode = HIBERNATION_SHUTDOWN; + + mutex_unlock(&pm_mutex); +} + +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_testmode(int mode) +{ + if (hibernation_mode == mode) { + hibernation_debug_sleep(); + return 1; + } + return 0; +} + +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_testmode(int mode) { return 0; } +static int hibernation_test(int level) { return 0; } +#endif /* !CONFIG_PM_DEBUG */ + +/** + * platform_begin - tell the platform driver that we're starting + * hibernation + */ + +static int platform_begin(int platform_mode) +{ + return (platform_mode && hibernation_ops) ? + hibernation_ops->begin() : 0; +} + +/** + * platform_end - tell the platform driver that we've entered the + * working state + */ + +static void platform_end(int platform_mode) +{ + if (platform_mode && hibernation_ops) + hibernation_ops->end(); +} + +/** + * platform_pre_snapshot - prepare the machine for hibernation using the + * platform driver if so configured and return an error code if it fails + */ + +static int platform_pre_snapshot(int platform_mode) +{ + return (platform_mode && hibernation_ops) ? + hibernation_ops->pre_snapshot() : 0; +} + +/** + * platform_leave - prepare the machine for switching to the normal mode + * of operation using the platform driver (called with interrupts disabled) + */ + +static void platform_leave(int platform_mode) +{ + if (platform_mode && hibernation_ops) + hibernation_ops->leave(); +} + +/** + * platform_finish - switch the machine to the normal mode of operation + * using the platform driver (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 the platform for the restoration 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 the platform 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 the platform from a failure to suspend + * devices. + */ + +static void platform_recover(int platform_mode) +{ + if (platform_mode && hibernation_ops && hibernation_ops->recover) + hibernation_ops->recover(); +} + +/** + * create_image - freeze devices that need to be frozen with interrupts + * off, create the hibernation image and thaw those devices. Control + * reappears in this routine after a restore. + */ + +static int create_image(int platform_mode) +{ + int error; + + error = arch_prepare_suspend(); + if (error) + return error; + + /* At this point, dpm_suspend_start() has been called, but *not* + * dpm_suspend_noirq(). We *must* call dpm_suspend_noirq() now. + * Otherwise, drivers for some devices (e.g. interrupt controllers) + * become desynchronized with the actual state of the hardware + * at resume time, and evil weirdness ensues. + */ + error = dpm_suspend_noirq(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) + || hibernation_testmode(HIBERNATION_TEST)) + goto Enable_cpus; + + local_irq_disable(); + + error = sysdev_suspend(PMSG_FREEZE); + if (error) { + printk(KERN_ERR "PM: Some system devices failed to power down, " + "aborting hibernation\n"); + goto Enable_irqs; + } + + if (hibernation_test(TEST_CORE)) + 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) + platform_leave(platform_mode); + + Power_up: + sysdev_resume(); + /* NOTE: dpm_resume_noirq() is just a resume() for devices + * that suspended with irqs off ... no overall powerup. + */ + + Enable_irqs: + local_irq_enable(); + + Enable_cpus: + enable_nonboot_cpus(); + + Platform_finish: + platform_finish(platform_mode); + + dpm_resume_noirq(in_suspend ? + (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); + + return error; +} + +/** + * hibernation_snapshot - quiesce devices and create the hibernation + * snapshot image. + * @platform_mode - if set, use the platform driver, if available, to + * prepare the platform firmware for the power transition. + * + * Must be called with pm_mutex held + */ + +int hibernation_snapshot(int platform_mode) +{ + int error; + + error = platform_begin(platform_mode); + if (error) + return error; + + /* Free memory before shutting down devices. */ + error = swsusp_shrink_memory(); + if (error) + goto Close; + + suspend_console(); + error = dpm_suspend_start(PMSG_FREEZE); + if (error) + goto Recover_platform; + + if (hibernation_test(TEST_DEVICES)) + goto Recover_platform; + + error = create_image(platform_mode); + /* Control returns here after successful restore */ + + Resume_devices: + dpm_resume_end(in_suspend ? + (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); + resume_console(); + Close: + platform_end(platform_mode); + return error; + + Recover_platform: + platform_recover(platform_mode); + goto Resume_devices; +} + +/** + * resume_target_kernel - prepare devices that need to be suspended with + * interrupts off, 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_noirq(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 = sysdev_suspend(PMSG_QUIESCE); + if (error) + goto Enable_irqs; + + /* We'll ignore saved state, but this gets preempt count (etc) right */ + 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 place where + * swsusp_arch_suspend() was called + */ + BUG_ON(!error); + /* This call to restore_highmem() undos 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(); + + sysdev_resume(); + + Enable_irqs: + local_irq_enable(); + + Enable_cpus: + enable_nonboot_cpus(); + + Cleanup: + platform_restore_cleanup(platform_mode); + + dpm_resume_noirq(PMSG_RECOVER); + + return error; +} + +/** + * hibernation_restore - quiesce devices and restore the hibernation + * snapshot image. If successful, control returns in hibernation_snaphot() + * @platform_mode - if set, use the platform driver, if available, to + * prepare the platform firmware for the transition. + * + * Must be called with pm_mutex held + */ + +int hibernation_restore(int platform_mode) +{ + int error; + + pm_prepare_console(); + suspend_console(); + error = dpm_suspend_start(PMSG_QUIESCE); + if (!error) { + error = resume_target_kernel(platform_mode); + dpm_resume_end(PMSG_RECOVER); + } + resume_console(); + pm_restore_console(); + return error; +} + +/** + * hibernation_platform_enter - enter the hibernation state using the + * platform driver (if available) + */ + +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_noirq(PMSG_HIBERNATE); + if (error) + goto Resume_devices; + + error = hibernation_ops->prepare(); + if (error) + goto Platofrm_finish; + + error = disable_nonboot_cpus(); + if (error) + goto Platofrm_finish; + + local_irq_disable(); + sysdev_suspend(PMSG_HIBERNATE); + hibernation_ops->enter(); + /* We should never get here */ + while (1); + + /* + * We don't need to reenable the nonboot CPUs or resume consoles, since + * the system is going to be halted anyway. + */ + Platofrm_finish: + hibernation_ops->finish(); + + dpm_suspend_noirq(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 so; otherwise try + * to power off or reboot. + */ + +static void power_down(void) +{ + switch (hibernation_mode) { + case HIBERNATION_TEST: + case HIBERNATION_TESTPROC: + break; + 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); +} + +static int prepare_processes(void) +{ + int error = 0; + + if (freeze_processes()) { + error = -EBUSY; + thaw_processes(); + } + return error; +} + +/** + * hibernate - The granpappy of the built-in hibernation management + */ + +int hibernate(void) +{ + int error; + + mutex_lock(&pm_mutex); + /* 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 = prepare_processes(); + if (error) + goto Finish; + + if (hibernation_test(TEST_FREEZER)) + goto Thaw; + + if (hibernation_testmode(HIBERNATION_TESTPROC)) + goto Thaw; + + error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM); + if (in_suspend && !error) { + unsigned int flags = 0; + + if (hibernation_mode == HIBERNATION_PLATFORM) + flags |= SF_PLATFORM_MODE; + pr_debug("PM: writing image.\n"); + error = swsusp_write(flags); + swsusp_free(); + if (!error) + power_down(); + } else { + pr_debug("PM: Image restored successfully.\n"); + swsusp_free(); + } + 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: + mutex_unlock(&pm_mutex); + return error; +} + + +/** + * software_resume - Resume from a saved image. + * + * Called as a late_initcall (so all devices are discovered and + * initialized), we call swsusp to see if we have a saved image or not. + * If so, we quiesce devices, the restore the saved image. We will + * return above (in hibernate() ) if everything goes well. + * Otherwise, we fail gracefully and return to the normally + * scheduled program. + * + */ + +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 image partition %s\n", resume_file); + + /* 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(); + /* + * 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: Resume from partition %d:%d\n", + MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device)); + + pr_debug("PM: Checking 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; + goto Unlock; + } + + pm_prepare_console(); + error = pm_notifier_call_chain(PM_RESTORE_PREPARE); + if (error) + goto Finish; + + error = usermodehelper_disable(); + if (error) + goto Finish; + + error = create_basic_memory_bitmaps(); + if (error) + goto Finish; + + pr_debug("PM: Preparing processes for restore.\n"); + error = prepare_processes(); + if (error) { + swsusp_close(FMODE_READ); + goto Done; + } + + pr_debug("PM: Reading hibernation image.\n"); + + error = swsusp_read(&flags); + if (!error) + hibernation_restore(flags & SF_PLATFORM_MODE); + + printk(KERN_ERR "PM: Restore failed, 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: Resume from disk failed.\n"); + return error; +} + +late_initcall(software_resume); + + +static const char * const hibernation_modes[] = { + [HIBERNATION_PLATFORM] = "platform", + [HIBERNATION_SHUTDOWN] = "shutdown", + [HIBERNATION_REBOOT] = "reboot", + [HIBERNATION_TEST] = "test", + [HIBERNATION_TESTPROC] = "testproc", +}; + +/** + * disk - Control hibernation mode + * + * Suspend-to-disk can be handled in several ways. We have a few options + * for putting the system to sleep - using the platform driver (e.g. ACPI + * or other hibernation_ops), powering off the system or rebooting the + * system (for testing) as well as the two test modes. + * + * The system can support 'platform', and that is known a priori (and + * encoded by the presence of hibernation_ops). However, the user may + * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the + * test modes, 'test' or 'testproc'. + * + * show() will display what the mode is currently set to. + * store() will accept one of + * + * 'platform' + * 'shutdown' + * 'reboot' + * 'test' + * 'testproc' + * + * It will only change to 'platform' if the system + * supports it (as determined by having hibernation_ops). + */ + +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: + case HIBERNATION_TEST: + case HIBERNATION_TESTPROC: + 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; + + mutex_lock(&pm_mutex); + 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: + case HIBERNATION_TEST: + case HIBERNATION_TESTPROC: + 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]); + mutex_unlock(&pm_mutex); + 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; + + mutex_lock(&pm_mutex); + swsusp_resume_device = res; + mutex_unlock(&pm_mutex); + 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 struct attribute * g[] = { + &disk_attr.attr, + &resume_attr.attr, + &image_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 noresume_setup(char *str) +{ + noresume = 1; + return 1; +} + +__setup("noresume", noresume_setup); +__setup("resume_offset=", resume_offset_setup); +__setup("resume=", resume_setup); |