/* * kernel/power/disk.c - Suspend-to-disk support. * * Copyright (c) 2003 Patrick Mochel * Copyright (c) 2003 Open Source Development Lab * Copyright (c) 2004 Pavel Machek <pavel@suse.cz> * * 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 "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; device_pm_lock(); local_irq_disable(); /* At this point, device_suspend() has been called, but *not* * device_power_down(). We *must* call device_power_down() 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 = device_power_down(PMSG_FREEZE); if (error) { printk(KERN_ERR "PM: Some devices failed to power down, " "aborting hibernation\n"); goto Enable_irqs; } sysdev_suspend(PMSG_FREEZE); if (error) { printk(KERN_ERR "PM: Some devices failed to power down, " "aborting hibernation\n"); goto Power_up_devices; } 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: device_power_up() is just a resume() for devices * that suspended with irqs off ... no overall powerup. */ Power_up_devices: device_power_up(in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); Enable_irqs: local_irq_enable(); device_pm_unlock(); 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 frimware 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 = device_suspend(PMSG_FREEZE); if (error) goto Recover_platform; if (hibernation_test(TEST_DEVICES)) goto Recover_platform; error = platform_pre_snapshot(platform_mode); if (error || hibernation_test(TEST_PLATFORM)) goto Finish; error = disable_nonboot_cpus(); if (!error) { if (hibernation_test(TEST_CPUS)) goto Enable_cpus; if (hibernation_testmode(HIBERNATION_TEST)) goto Enable_cpus; error = create_image(platform_mode); /* Control returns here after successful restore */ } Enable_cpus: enable_nonboot_cpus(); Finish: platform_finish(platform_mode); Resume_devices: device_resume(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(void) { int error; device_pm_lock(); local_irq_disable(); error = device_power_down(PMSG_QUIESCE); if (error) { printk(KERN_ERR "PM: Some devices failed to power down, " "aborting resume\n"); goto Enable_irqs; } sysdev_suspend(PMSG_QUIESCE); /* 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(); device_power_up(PMSG_RECOVER); Enable_irqs: local_irq_enable(); device_pm_unlock(); 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 frimware for the transition. * * Must be called with pm_mutex held */ int hibernation_restore(int platform_mode) { int error; pm_prepare_console(); suspend_console(); error = device_suspend(PMSG_QUIESCE); if (error) goto Finish; error = platform_pre_restore(platform_mode); if (!error) { error = disable_nonboot_cpus(); if (!error) error = resume_target_kernel(); enable_nonboot_cpus(); } platform_restore_cleanup(platform_mode); device_resume(PMSG_RECOVER); Finish: 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 = device_suspend(PMSG_HIBERNATE); if (error) { if (hibernation_ops->recover) hibernation_ops->recover(); goto Resume_devices; } error = hibernation_ops->prepare(); if (error) goto Resume_devices; error = disable_nonboot_cpus(); if (error) goto Finish; device_pm_lock(); local_irq_disable(); error = device_power_down(PMSG_HIBERNATE); if (!error) { sysdev_suspend(PMSG_HIBERNATE); hibernation_ops->enter(); /* We should never get here */ while (1); } local_irq_enable(); device_pm_unlock(); /* * We don't need to reenable the nonboot CPUs or resume consoles, since * the system is going to be halted anyway. */ Finish: hibernation_ops->finish(); Resume_devices: entering_platform_hibernation = false; device_resume(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) { if (!strlen(resume_file)) { mutex_unlock(&pm_mutex); return -ENOENT; } /* * Some device discovery might still be in progress; we need * to wait for this to finish. */ wait_for_device_probe(); swsusp_resume_device = name_to_dev_t(resume_file); pr_debug("PM: Resume from partition %s\n", resume_file); } else { pr_debug("PM: Resume from partition %d:%d\n", MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device)); } if (noresume) { /** * FIXME: If noresume is specified, we need to find the * partition and reset it back to normal swap space. */ mutex_unlock(&pm_mutex); return 0; } 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);