File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
new file mode 100644
index 0000000..3124ceb
--- /dev/null
+++ b/kernel/power/hibernate.c
@@ -0,0 +1,1169 @@
+/*
+ * 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>
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/export.h>
+#include <linux/suspend.h>
+#include <linux/syscalls.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/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/genhd.h>
+#include <linux/ktime.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
+ /* 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;
+
+bool hibernation_available(void)
+{
+ return (nohibernate == 0);
+}
+
+/**
+ * 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();
+}
+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)
+{
+ 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(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;
+ printk(KERN_INFO "PM: %s %u kbytes in %u.%02u seconds (%u.%02u 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();
+ 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)
+ printk(KERN_ERR "PM: Error %d creating hibernation image\n",
+ error);
+ 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;
+
+ 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;
+}
+
+/**
+ * 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);
+ /*
+ * 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();
+ 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 Enable_cpus;
+
+ 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_cpus:
+ 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)
+{
+#ifdef CONFIG_SUSPEND
+ int error;
+#endif
+
+ switch (hibernation_mode) {
+ case HIBERNATION_REBOOT:
+ kernel_restart(NULL);
+ break;
+ case HIBERNATION_PLATFORM:
+ hibernation_platform_enter();
+ case HIBERNATION_SHUTDOWN:
+ if (pm_power_off)
+ kernel_power_off();
+ break;
+#ifdef CONFIG_SUSPEND
+ case HIBERNATION_SUSPEND:
+ error = suspend_devices_and_enter(PM_SUSPEND_MEM);
+ if (error) {
+ if (hibernation_ops)
+ hibernation_mode = HIBERNATION_PLATFORM;
+ else
+ hibernation_mode = HIBERNATION_SHUTDOWN;
+ power_down();
+ }
+ /*
+ * Restore swap signature.
+ */
+ error = swsusp_unmark();
+ if (error)
+ printk(KERN_ERR "PM: Swap will be unusable! "
+ "Try swapon -a.\n");
+ return;
+#endif
+ }
+ 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)
+ cpu_relax();
+}
+
+/**
+ * hibernate - Carry out system hibernation, including saving the image.
+ */
+int hibernate(void)
+{
+ int error;
+
+ if (!hibernation_available()) {
+ pr_debug("PM: Hibernation not available.\n");
+ return -EPERM;
+ }
+
+ 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;
+
+ printk(KERN_INFO "PM: Syncing filesystems ... ");
+ sys_sync();
+ printk("done.\n");
+
+ error = freeze_processes();
+ if (error)
+ goto Exit;
+
+ 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;
+
+ 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");
+ }
+
+ Free_bitmaps:
+ free_basic_memory_bitmaps();
+ Thaw:
+ unlock_device_hotplug();
+ thaw_processes();
+
+ /* Don't bother checking whether freezer_test_done is true */
+ freezer_test_done = false;
+ 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_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;
+ unsigned int flags;
+
+ /*
+ * 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 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);
+
+ /*
+ * name_to_dev_t is ineffective to verify parition if resume_file is in
+ * integer format. (e.g. major:minor)
+ */
+ if (isdigit(resume_file[0]) && resume_wait) {
+ int partno;
+ while (!get_gendisk(swsusp_resume_device, &partno))
+ msleep(10);
+ }
+
+ 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:
+ 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;
+
+ pr_debug("PM: Preparing processes for restore.\n");
+ error = freeze_processes();
+ if (error)
+ goto Close_Finish;
+
+ pr_debug("PM: Loading hibernation image.\n");
+
+ lock_device_hotplug();
+ error = create_basic_memory_bitmaps();
+ if (error)
+ goto Thaw;
+
+ 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();
+ free_basic_memory_bitmaps();
+ Thaw:
+ unlock_device_hotplug();
+ thaw_processes();
+ 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_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
+};
+
+/*
+ * /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
+ 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;
+
+ if (!hibernation_available())
+ return -EPERM;
+
+ 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:
+#ifdef CONFIG_SUSPEND
+ case HIBERNATION_SUSPEND:
+#endif
+ 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)
+{
+ dev_t res;
+ int len = n;
+ char *name;
+
+ 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;
+
+ lock_system_sleep();
+ swsusp_resume_device = res;
+ unlock_system_sleep();
+ printk(KERN_INFO "PM: Starting manual resume from disk\n");
+ noresume = 0;
+ software_resume();
+ return n;
+}
+
+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;
+ else if (!strncmp(str, "no", 2)) {
+ noresume = 1;
+ nohibernate = 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)
+{
+ int rc = kstrtouint(str, 0, &resume_delay);
+
+ if (rc)
+ return rc;
+ return 1;
+}
+
+static int __init nohibernate_setup(char *str)
+{
+ noresume = 1;
+ nohibernate = 1;
+ return 1;
+}
+
+static int __init kaslr_nohibernate_setup(char *str)
+{
+ return nohibernate_setup(str);
+}
+
+__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);
+__setup("kaslr", kaslr_nohibernate_setup);