diff options
Diffstat (limited to 'kernel/power/hibernate.c')
| -rw-r--r-- | kernel/power/hibernate.c | 1367 |
1 files changed, 1367 insertions, 0 deletions
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c new file mode 100644 index 000000000..30d1274f0 --- /dev/null +++ b/kernel/power/hibernate.c @@ -0,0 +1,1367 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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@ucw.cz> + * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc. + * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com> + */ + +#define pr_fmt(fmt) "PM: hibernation: " fmt + +#include <linux/export.h> +#include <linux/suspend.h> +#include <linux/reboot.h> +#include <linux/string.h> +#include <linux/device.h> +#include <linux/async.h> +#include <linux/delay.h> +#include <linux/fs.h> +#include <linux/mount.h> +#include <linux/pm.h> +#include <linux/nmi.h> +#include <linux/console.h> +#include <linux/cpu.h> +#include <linux/freezer.h> +#include <linux/gfp.h> +#include <linux/syscore_ops.h> +#include <linux/ctype.h> +#include <linux/ktime.h> +#include <linux/security.h> +#include <linux/secretmem.h> +#include <trace/events/power.h> + +#include "power.h" + + +static int nocompress; +static int noresume; +static int nohibernate; +static int resume_wait; +static unsigned int resume_delay; +static char resume_file[256] = CONFIG_PM_STD_PARTITION; +dev_t swsusp_resume_device; +sector_t swsusp_resume_block; +__visible int in_suspend __nosavedata; + +enum { + HIBERNATION_INVALID, + HIBERNATION_PLATFORM, + HIBERNATION_SHUTDOWN, + HIBERNATION_REBOOT, +#ifdef CONFIG_SUSPEND + HIBERNATION_SUSPEND, +#endif + HIBERNATION_TEST_RESUME, + /* 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; +bool snapshot_test; + +static const struct platform_hibernation_ops *hibernation_ops; + +static atomic_t hibernate_atomic = ATOMIC_INIT(1); + +bool hibernate_acquire(void) +{ + return atomic_add_unless(&hibernate_atomic, -1, 0); +} + +void hibernate_release(void) +{ + atomic_inc(&hibernate_atomic); +} + +bool hibernation_available(void) +{ + return nohibernate == 0 && + !security_locked_down(LOCKDOWN_HIBERNATION) && + !secretmem_active() && !cxl_mem_active(); +} + +/** + * 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) +{ + unsigned int sleep_flags; + + 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; + } + + sleep_flags = 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(sleep_flags); +} +EXPORT_SYMBOL_GPL(hibernation_set_ops); + +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) +{ + pr_info("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(PMSG_FREEZE) : 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(ktime_t start, ktime_t stop, + unsigned nr_pages, char *msg) +{ + ktime_t diff; + u64 elapsed_centisecs64; + unsigned int centisecs; + unsigned int k; + unsigned int kps; + + diff = ktime_sub(stop, start); + elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC); + centisecs = elapsed_centisecs64; + if (centisecs == 0) + centisecs = 1; /* avoid div-by-zero */ + k = nr_pages * (PAGE_SIZE / 1024); + kps = (k * 100) / centisecs; + pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n", + msg, k, centisecs / 100, centisecs % 100, kps / 1000, + (kps % 1000) / 10); +} + +__weak int arch_resume_nosmt(void) +{ + return 0; +} + +/** + * 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) { + pr_err("Some devices failed to power down, aborting\n"); + return error; + } + + error = platform_pre_snapshot(platform_mode); + if (error || hibernation_test(TEST_PLATFORM)) + goto Platform_finish; + + error = pm_sleep_disable_secondary_cpus(); + if (error || hibernation_test(TEST_CPUS)) + goto Enable_cpus; + + local_irq_disable(); + + system_state = SYSTEM_SUSPEND; + + error = syscore_suspend(); + if (error) { + pr_err("Some system devices failed to power down, aborting\n"); + goto Enable_irqs; + } + + if (hibernation_test(TEST_CORE) || pm_wakeup_pending()) + goto Power_up; + + in_suspend = 1; + save_processor_state(); + trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true); + error = swsusp_arch_suspend(); + /* Restore control flow magically appears here */ + restore_processor_state(); + trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false); + if (error) + pr_err("Error %d creating image\n", error); + + if (!in_suspend) { + events_check_enabled = false; + clear_or_poison_free_pages(); + } + + platform_leave(platform_mode); + + Power_up: + syscore_resume(); + + Enable_irqs: + system_state = SYSTEM_RUNNING; + local_irq_enable(); + + Enable_cpus: + pm_sleep_enable_secondary_cpus(); + + /* Allow architectures to do nosmt-specific post-resume dances */ + if (!in_suspend) + error = arch_resume_nosmt(); + + 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 system_transition_mutex held. + */ +int hibernation_snapshot(int platform_mode) +{ + pm_message_t msg; + int error; + + pm_suspend_clear_flags(); + 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; +} + +int __weak hibernate_resume_nonboot_cpu_disable(void) +{ + return suspend_disable_secondary_cpus(); +} + +/** + * 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) { + pr_err("Some devices failed to power down, aborting resume\n"); + return error; + } + + error = platform_pre_restore(platform_mode); + if (error) + goto Cleanup; + + cpuidle_pause(); + + error = hibernate_resume_nonboot_cpu_disable(); + if (error) + goto Enable_cpus; + + local_irq_disable(); + system_state = SYSTEM_SUSPEND; + + 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: + system_state = SYSTEM_RUNNING; + local_irq_enable(); + + Enable_cpus: + pm_sleep_enable_secondary_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 system_transition_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); + /* + * The above should either succeed and jump to the new kernel, + * or return with an error. Otherwise things are just + * undefined, so let's be paranoid. + */ + BUG_ON(!error); + } + 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(PMSG_HIBERNATE); + 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 = pm_sleep_disable_secondary_cpus(); + if (error) + goto Enable_cpus; + + local_irq_disable(); + system_state = SYSTEM_SUSPEND; + 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(); + system_state = SYSTEM_RUNNING; + local_irq_enable(); + + Enable_cpus: + pm_sleep_enable_secondary_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) +{ +#ifdef CONFIG_SUSPEND + int error; + + if (hibernation_mode == HIBERNATION_SUSPEND) { + error = suspend_devices_and_enter(mem_sleep_current); + if (error) { + hibernation_mode = hibernation_ops ? + HIBERNATION_PLATFORM : + HIBERNATION_SHUTDOWN; + } else { + /* Restore swap signature. */ + error = swsusp_unmark(); + if (error) + pr_err("Swap will be unusable! Try swapon -a.\n"); + + return; + } + } +#endif + + switch (hibernation_mode) { + case HIBERNATION_REBOOT: + kernel_restart(NULL); + break; + case HIBERNATION_PLATFORM: + hibernation_platform_enter(); + fallthrough; + case HIBERNATION_SHUTDOWN: + if (kernel_can_power_off()) + kernel_power_off(); + break; + } + kernel_halt(); + /* + * Valid image is on the disk, if we continue we risk serious data + * corruption after resume. + */ + pr_crit("Power down manually\n"); + while (1) + cpu_relax(); +} + +static int load_image_and_restore(void) +{ + int error; + unsigned int flags; + fmode_t mode = FMODE_READ; + + if (snapshot_test) + mode |= FMODE_EXCL; + + pm_pr_dbg("Loading hibernation image.\n"); + + lock_device_hotplug(); + error = create_basic_memory_bitmaps(); + if (error) { + swsusp_close(mode); + goto Unlock; + } + + error = swsusp_read(&flags); + swsusp_close(mode); + if (!error) + error = hibernation_restore(flags & SF_PLATFORM_MODE); + + pr_err("Failed to load image, recovering.\n"); + swsusp_free(); + free_basic_memory_bitmaps(); + Unlock: + unlock_device_hotplug(); + + return error; +} + +/** + * hibernate - Carry out system hibernation, including saving the image. + */ +int hibernate(void) +{ + unsigned int sleep_flags; + int error; + + if (!hibernation_available()) { + pm_pr_dbg("Hibernation not available.\n"); + return -EPERM; + } + + sleep_flags = lock_system_sleep(); + /* The snapshot device should not be opened while we're running */ + if (!hibernate_acquire()) { + error = -EBUSY; + goto Unlock; + } + + pr_info("hibernation entry\n"); + pm_prepare_console(); + error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION); + if (error) + goto Restore; + + ksys_sync_helper(); + + error = freeze_processes(); + if (error) + goto Exit; + + /* protected by system_transition_mutex */ + snapshot_test = false; + + lock_device_hotplug(); + /* Allocate memory management structures */ + error = create_basic_memory_bitmaps(); + if (error) + goto Thaw; + + error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM); + if (error || freezer_test_done) + goto Free_bitmaps; + + 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; + + pm_pr_dbg("Writing hibernation image.\n"); + error = swsusp_write(flags); + swsusp_free(); + if (!error) { + if (hibernation_mode == HIBERNATION_TEST_RESUME) + snapshot_test = true; + else + power_down(); + } + in_suspend = 0; + pm_restore_gfp_mask(); + } else { + pm_pr_dbg("Hibernation image restored successfully.\n"); + } + + Free_bitmaps: + free_basic_memory_bitmaps(); + Thaw: + unlock_device_hotplug(); + if (snapshot_test) { + pm_pr_dbg("Checking hibernation image\n"); + error = swsusp_check(); + if (!error) + error = load_image_and_restore(); + } + thaw_processes(); + + /* Don't bother checking whether freezer_test_done is true */ + freezer_test_done = false; + Exit: + pm_notifier_call_chain(PM_POST_HIBERNATION); + Restore: + pm_restore_console(); + hibernate_release(); + Unlock: + unlock_system_sleep(sleep_flags); + pr_info("hibernation exit\n"); + + return error; +} + +/** + * hibernate_quiet_exec - Execute a function with all devices frozen. + * @func: Function to execute. + * @data: Data pointer to pass to @func. + * + * Return the @func return value or an error code if it cannot be executed. + */ +int hibernate_quiet_exec(int (*func)(void *data), void *data) +{ + unsigned int sleep_flags; + int error; + + sleep_flags = lock_system_sleep(); + + if (!hibernate_acquire()) { + error = -EBUSY; + goto unlock; + } + + pm_prepare_console(); + + error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION); + if (error) + goto restore; + + error = freeze_processes(); + if (error) + goto exit; + + lock_device_hotplug(); + + pm_suspend_clear_flags(); + + error = platform_begin(true); + if (error) + goto thaw; + + error = freeze_kernel_threads(); + if (error) + goto thaw; + + error = dpm_prepare(PMSG_FREEZE); + if (error) + goto dpm_complete; + + suspend_console(); + + error = dpm_suspend(PMSG_FREEZE); + if (error) + goto dpm_resume; + + error = dpm_suspend_end(PMSG_FREEZE); + if (error) + goto dpm_resume; + + error = platform_pre_snapshot(true); + if (error) + goto skip; + + error = func(data); + +skip: + platform_finish(true); + + dpm_resume_start(PMSG_THAW); + +dpm_resume: + dpm_resume(PMSG_THAW); + + resume_console(); + +dpm_complete: + dpm_complete(PMSG_THAW); + + thaw_kernel_threads(); + +thaw: + platform_end(true); + + unlock_device_hotplug(); + + thaw_processes(); + +exit: + pm_notifier_call_chain(PM_POST_HIBERNATION); + +restore: + pm_restore_console(); + + hibernate_release(); + +unlock: + unlock_system_sleep(sleep_flags); + + return error; +} +EXPORT_SYMBOL_GPL(hibernate_quiet_exec); + +/** + * 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_snapshot() 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; + + /* + * If the user said "noresume".. bail out early. + */ + if (noresume || !hibernation_available()) + 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 system_transition_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(&system_transition_mutex, SINGLE_DEPTH_NESTING); + + snapshot_test = false; + + if (swsusp_resume_device) + goto Check_image; + + if (!strlen(resume_file)) { + error = -ENOENT; + goto Unlock; + } + + pm_pr_dbg("Checking hibernation image partition %s\n", resume_file); + + if (resume_delay) { + pr_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(); + } + + swsusp_resume_device = name_to_dev_t(resume_file); + if (!swsusp_resume_device) { + error = -ENODEV; + goto Unlock; + } + } + + Check_image: + pm_pr_dbg("Hibernation image partition %d:%d present\n", + MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device)); + + pm_pr_dbg("Looking for hibernation image.\n"); + error = swsusp_check(); + if (error) + goto Unlock; + + /* The snapshot device should not be opened while we're running */ + if (!hibernate_acquire()) { + error = -EBUSY; + swsusp_close(FMODE_READ | FMODE_EXCL); + goto Unlock; + } + + pr_info("resume from hibernation\n"); + pm_prepare_console(); + error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE); + if (error) + goto Restore; + + pm_pr_dbg("Preparing processes for hibernation restore.\n"); + error = freeze_processes(); + if (error) + goto Close_Finish; + + error = freeze_kernel_threads(); + if (error) { + thaw_processes(); + goto Close_Finish; + } + + error = load_image_and_restore(); + thaw_processes(); + Finish: + pm_notifier_call_chain(PM_POST_RESTORE); + Restore: + pm_restore_console(); + pr_info("resume failed (%d)\n", error); + hibernate_release(); + /* For success case, the suspend path will release the lock */ + Unlock: + mutex_unlock(&system_transition_mutex); + pm_pr_dbg("Hibernation image not present or could not be loaded.\n"); + return error; + Close_Finish: + swsusp_close(FMODE_READ | FMODE_EXCL); + goto Finish; +} + +late_initcall_sync(software_resume); + + +static const char * const hibernation_modes[] = { + [HIBERNATION_PLATFORM] = "platform", + [HIBERNATION_SHUTDOWN] = "shutdown", + [HIBERNATION_REBOOT] = "reboot", +#ifdef CONFIG_SUSPEND + [HIBERNATION_SUSPEND] = "suspend", +#endif + [HIBERNATION_TEST_RESUME] = "test_resume", +}; + +/* + * /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; + + if (!hibernation_available()) + return sprintf(buf, "[disabled]\n"); + + for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) { + if (!hibernation_modes[i]) + continue; + switch (i) { + case HIBERNATION_SHUTDOWN: + case HIBERNATION_REBOOT: +#ifdef CONFIG_SUSPEND + case HIBERNATION_SUSPEND: +#endif + case HIBERNATION_TEST_RESUME: + 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 mode = HIBERNATION_INVALID; + unsigned int sleep_flags; + int error = 0; + int len; + char *p; + int i; + + if (!hibernation_available()) + return -EPERM; + + p = memchr(buf, '\n', n); + len = p ? p - buf : n; + + sleep_flags = 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: +#ifdef CONFIG_SUSPEND + case HIBERNATION_SUSPEND: +#endif + case HIBERNATION_TEST_RESUME: + hibernation_mode = mode; + break; + case HIBERNATION_PLATFORM: + if (hibernation_ops) + hibernation_mode = mode; + else + error = -EINVAL; + } + } else + error = -EINVAL; + + if (!error) + pm_pr_dbg("Hibernation mode set to '%s'\n", + hibernation_modes[mode]); + unlock_system_sleep(sleep_flags); + 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 sleep_flags; + int len = n; + char *name; + dev_t res; + + if (len && buf[len-1] == '\n') + len--; + name = kstrndup(buf, len, GFP_KERNEL); + if (!name) + return -ENOMEM; + + res = name_to_dev_t(name); + kfree(name); + if (!res) + return -EINVAL; + + sleep_flags = lock_system_sleep(); + swsusp_resume_device = res; + unlock_system_sleep(sleep_flags); + + pm_pr_dbg("Configured hibernation resume from disk to %u\n", + swsusp_resume_device); + noresume = 0; + software_resume(); + return n; +} + +power_attr(resume); + +static ssize_t resume_offset_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block); +} + +static ssize_t resume_offset_store(struct kobject *kobj, + struct kobj_attribute *attr, const char *buf, + size_t n) +{ + unsigned long long offset; + int rc; + + rc = kstrtoull(buf, 0, &offset); + if (rc) + return rc; + swsusp_resume_block = offset; + + return n; +} + +power_attr(resume_offset); + +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_offset_attr.attr, + &resume_attr.attr, + &image_size_attr.attr, + &reserved_size_attr.attr, + NULL, +}; + + +static const 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; + } else if (!strncmp(str, "no", 2)) { + noresume = 1; + nohibernate = 1; + } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) + && !strncmp(str, "protect_image", 13)) { + enable_restore_image_protection(); + } + 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) +{ + int rc = kstrtouint(str, 0, &resume_delay); + + if (rc) + pr_warn("resumedelay: bad option string '%s'\n", str); + return 1; +} + +static int __init nohibernate_setup(char *str) +{ + noresume = 1; + nohibernate = 1; + 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); +__setup("nohibernate", nohibernate_setup); |