Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

17 files changed, 10907 insertions, 0 deletions

diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
new file mode 100644
index 000000000..4b31629c5
--- /dev/null
+++ b/kernel/power/Kconfig
@@ -0,0 +1,352 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config SUSPEND
+	bool "Suspend to RAM and standby"
+	depends on ARCH_SUSPEND_POSSIBLE
+	default y
+	help
+	  Allow the system to enter sleep states in which main memory is
+	  powered and thus its contents are preserved, such as the
+	  suspend-to-RAM state (e.g. the ACPI S3 state).
+
+config SUSPEND_FREEZER
+	bool "Enable freezer for suspend to RAM/standby" \
+		if ARCH_WANTS_FREEZER_CONTROL || BROKEN
+	depends on SUSPEND
+	default y
+	help
+	  This allows you to turn off the freezer for suspend. If this is
+	  done, no tasks are frozen for suspend to RAM/standby.
+
+	  Turning OFF this setting is NOT recommended! If in doubt, say Y.
+
+config SUSPEND_SKIP_SYNC
+	bool "Skip kernel's sys_sync() on suspend to RAM/standby"
+	depends on SUSPEND
+	depends on EXPERT
+	help
+	  Skip the kernel sys_sync() before freezing user processes.
+	  Some systems prefer not to pay this cost on every invocation
+	  of suspend, or they are content with invoking sync() from
+	  user-space before invoking suspend.  There's a run-time switch
+	  at '/sys/power/sync_on_suspend' to configure this behaviour.
+	  This setting changes the default for the run-tim switch. Say Y
+	  to change the default to disable the kernel sys_sync().
+
+config HIBERNATE_CALLBACKS
+	bool
+
+config HIBERNATION
+	bool "Hibernation (aka 'suspend to disk')"
+	depends on SWAP && ARCH_HIBERNATION_POSSIBLE
+	select HIBERNATE_CALLBACKS
+	select LZO_COMPRESS
+	select LZO_DECOMPRESS
+	select CRC32
+	help
+	  Enable the suspend to disk (STD) functionality, which is usually
+	  called "hibernation" in user interfaces.  STD checkpoints the
+	  system and powers it off; and restores that checkpoint on reboot.
+
+	  You can suspend your machine with 'echo disk > /sys/power/state'
+	  after placing resume=/dev/swappartition on the kernel command line
+	  in your bootloader's configuration file.
+
+	  Alternatively, you can use the additional userland tools available
+	  from <http://suspend.sf.net>.
+
+	  In principle it does not require ACPI or APM, although for example
+	  ACPI will be used for the final steps when it is available.  One
+	  of the reasons to use software suspend is that the firmware hooks
+	  for suspend states like suspend-to-RAM (STR) often don't work very
+	  well with Linux.
+
+	  It creates an image which is saved in your active swap. Upon the next
+	  boot, pass the 'resume=/dev/swappartition' argument to the kernel to
+	  have it detect the saved image, restore memory state from it, and
+	  continue to run as before. If you do not want the previous state to
+	  be reloaded, then use the 'noresume' kernel command line argument.
+	  Note, however, that fsck will be run on your filesystems and you will
+	  need to run mkswap against the swap partition used for the suspend.
+
+	  It also works with swap files to a limited extent (for details see
+	  <file:Documentation/power/swsusp-and-swap-files.rst>).
+
+	  Right now you may boot without resuming and resume later but in the
+	  meantime you cannot use the swap partition(s)/file(s) involved in
+	  suspending.  Also in this case you must not use the filesystems
+	  that were mounted before the suspend.  In particular, you MUST NOT
+	  MOUNT any journaled filesystems mounted before the suspend or they
+	  will get corrupted in a nasty way.
+
+	  For more information take a look at <file:Documentation/power/swsusp.rst>.
+
+config HIBERNATION_SNAPSHOT_DEV
+	bool "Userspace snapshot device"
+	depends on HIBERNATION
+	default y
+	help
+	  Device used by the uswsusp tools.
+
+	  Say N if no snapshotting from userspace is needed, this also
+	  reduces the attack surface of the kernel.
+
+	  If in doubt, say Y.
+
+config PM_STD_PARTITION
+	string "Default resume partition"
+	depends on HIBERNATION
+	default ""
+	help
+	  The default resume partition is the partition that the suspend-
+	  to-disk implementation will look for a suspended disk image.
+
+	  The partition specified here will be different for almost every user.
+	  It should be a valid swap partition (at least for now) that is turned
+	  on before suspending.
+
+	  The partition specified can be overridden by specifying:
+
+		resume=/dev/<other device>
+
+	  which will set the resume partition to the device specified.
+
+	  Note there is currently not a way to specify which device to save the
+	  suspended image to. It will simply pick the first available swap
+	  device.
+
+config PM_SLEEP
+	def_bool y
+	depends on SUSPEND || HIBERNATE_CALLBACKS
+	select PM
+
+config PM_SLEEP_SMP
+	def_bool y
+	depends on SMP
+	depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE
+	depends on PM_SLEEP
+	select HOTPLUG_CPU
+
+config PM_SLEEP_SMP_NONZERO_CPU
+	def_bool y
+	depends on PM_SLEEP_SMP
+	depends on ARCH_SUSPEND_NONZERO_CPU
+	help
+	If an arch can suspend (for suspend, hibernate, kexec, etc) on a
+	non-zero numbered CPU, it may define ARCH_SUSPEND_NONZERO_CPU. This
+	will allow nohz_full mask to include CPU0.
+
+config PM_AUTOSLEEP
+	bool "Opportunistic sleep"
+	depends on PM_SLEEP
+	help
+	Allow the kernel to trigger a system transition into a global sleep
+	state automatically whenever there are no active wakeup sources.
+
+config PM_USERSPACE_AUTOSLEEP
+	bool "Userspace opportunistic sleep"
+	depends on PM_SLEEP
+	help
+	Notify kernel of aggressive userspace autosleep power management policy.
+
+	This option changes the behavior of various sleep-sensitive code to deal
+	with frequent userspace-initiated transitions into a global sleep state.
+
+	Saying Y here, disables code paths that most users really should keep
+	enabled. In particular, only enable this if it is very common to be
+	asleep/awake for very short periods of time (<= 2 seconds).
+
+	Only platforms, such as Android, that implement opportunistic sleep from
+	a userspace power manager service should enable this option; and not
+	other machines. Therefore, you should say N here, unless you are
+	extremely certain that this is what you want. The option otherwise has
+	bad, undesirable effects, and should not be enabled just for fun.
+
+
+config PM_WAKELOCKS
+	bool "User space wakeup sources interface"
+	depends on PM_SLEEP
+	help
+	Allow user space to create, activate and deactivate wakeup source
+	objects with the help of a sysfs-based interface.
+
+config PM_WAKELOCKS_LIMIT
+	int "Maximum number of user space wakeup sources (0 = no limit)"
+	range 0 100000
+	default 100
+	depends on PM_WAKELOCKS
+
+config PM_WAKELOCKS_GC
+	bool "Garbage collector for user space wakeup sources"
+	depends on PM_WAKELOCKS
+	default y
+
+config PM
+	bool "Device power management core functionality"
+	help
+	  Enable functionality allowing I/O devices to be put into energy-saving
+	  (low power) states, for example after a specified period of inactivity
+	  (autosuspended), and woken up in response to a hardware-generated
+	  wake-up event or a driver's request.
+
+	  Hardware support is generally required for this functionality to work
+	  and the bus type drivers of the buses the devices are on are
+	  responsible for the actual handling of device suspend requests and
+	  wake-up events.
+
+config PM_DEBUG
+	bool "Power Management Debug Support"
+	depends on PM
+	help
+	This option enables various debugging support in the Power Management
+	code. This is helpful when debugging and reporting PM bugs, like
+	suspend support.
+
+config PM_ADVANCED_DEBUG
+	bool "Extra PM attributes in sysfs for low-level debugging/testing"
+	depends on PM_DEBUG
+	help
+	Add extra sysfs attributes allowing one to access some Power Management
+	fields of device objects from user space.  If you are not a kernel
+	developer interested in debugging/testing Power Management, say "no".
+
+config PM_TEST_SUSPEND
+	bool "Test suspend/resume and wakealarm during bootup"
+	depends on SUSPEND && PM_DEBUG && RTC_CLASS=y
+	help
+	This option will let you suspend your machine during bootup, and
+	make it wake up a few seconds later using an RTC wakeup alarm.
+	Enable this with a kernel parameter like "test_suspend=mem".
+
+	You probably want to have your system's RTC driver statically
+	linked, ensuring that it's available when this test runs.
+
+config PM_SLEEP_DEBUG
+	def_bool y
+	depends on PM_DEBUG && PM_SLEEP
+
+config DPM_WATCHDOG
+	bool "Device suspend/resume watchdog"
+	depends on PM_DEBUG && PSTORE && EXPERT
+	help
+	  Sets up a watchdog timer to capture drivers that are
+	  locked up attempting to suspend/resume a device.
+	  A detected lockup causes system panic with message
+	  captured in pstore device for inspection in subsequent
+	  boot session.
+
+config DPM_WATCHDOG_TIMEOUT
+	int "Watchdog timeout in seconds"
+	range 1 120
+	default 120
+	depends on DPM_WATCHDOG
+
+config PM_TRACE
+	bool
+	help
+	  This enables code to save the last PM event point across
+	  reboot. The architecture needs to support this, x86 for
+	  example does by saving things in the RTC, see below.
+
+	  The architecture specific code must provide the extern
+	  functions from <linux/resume-trace.h> as well as the
+	  <asm/resume-trace.h> header with a TRACE_RESUME() macro.
+
+	  The way the information is presented is architecture-
+	  dependent, x86 will print the information during a
+	  late_initcall.
+
+config PM_TRACE_RTC
+	bool "Suspend/resume event tracing"
+	depends on PM_SLEEP_DEBUG
+	depends on X86
+	select PM_TRACE
+	help
+	This enables some cheesy code to save the last PM event point in the
+	RTC across reboots, so that you can debug a machine that just hangs
+	during suspend (or more commonly, during resume).
+
+	To use this debugging feature you should attempt to suspend the
+	machine, reboot it and then run
+
+		dmesg -s 1000000 | grep 'hash matches'
+
+	CAUTION: this option will cause your machine's real-time clock to be
+	set to an invalid time after a resume.
+
+config APM_EMULATION
+	tristate "Advanced Power Management Emulation"
+	depends on SYS_SUPPORTS_APM_EMULATION
+	help
+	  APM is a BIOS specification for saving power using several different
+	  techniques. This is mostly useful for battery powered laptops with
+	  APM compliant BIOSes. If you say Y here, the system time will be
+	  reset after a RESUME operation, the /proc/apm device will provide
+	  battery status information, and user-space programs will receive
+	  notification of APM "events" (e.g. battery status change).
+
+	  In order to use APM, you will need supporting software. For location
+	  and more information, read <file:Documentation/power/apm-acpi.rst>
+	  and the Battery Powered Linux mini-HOWTO, available from
+	  <http://www.tldp.org/docs.html#howto>.
+
+	  This driver does not spin down disk drives (see the hdparm(8)
+	  manpage ("man 8 hdparm") for that), and it doesn't turn off
+	  VESA-compliant "green" monitors.
+
+	  Generally, if you don't have a battery in your machine, there isn't
+	  much point in using this driver and you should say N. If you get
+	  random kernel OOPSes or reboots that don't seem to be related to
+	  anything, try disabling/enabling this option (or disabling/enabling
+	  APM in your BIOS).
+
+config PM_CLK
+	def_bool y
+	depends on PM && HAVE_CLK
+
+config PM_GENERIC_DOMAINS
+	bool
+	depends on PM
+
+config WQ_POWER_EFFICIENT_DEFAULT
+	bool "Enable workqueue power-efficient mode by default"
+	depends on PM
+	help
+	  Per-cpu workqueues are generally preferred because they show
+	  better performance thanks to cache locality; unfortunately,
+	  per-cpu workqueues tend to be more power hungry than unbound
+	  workqueues.
+
+	  Enabling workqueue.power_efficient kernel parameter makes the
+	  per-cpu workqueues which were observed to contribute
+	  significantly to power consumption unbound, leading to measurably
+	  lower power usage at the cost of small performance overhead.
+
+	  This config option determines whether workqueue.power_efficient
+	  is enabled by default.
+
+	  If in doubt, say N.
+
+config PM_GENERIC_DOMAINS_SLEEP
+	def_bool y
+	depends on PM_SLEEP && PM_GENERIC_DOMAINS
+
+config PM_GENERIC_DOMAINS_OF
+	def_bool y
+	depends on PM_GENERIC_DOMAINS && OF
+
+config CPU_PM
+	bool
+
+config ENERGY_MODEL
+	bool "Energy Model for devices with DVFS (CPUs, GPUs, etc)"
+	depends on SMP
+	depends on CPU_FREQ
+	help
+	  Several subsystems (thermal and/or the task scheduler for example)
+	  can leverage information about the energy consumed by devices to
+	  make smarter decisions. This config option enables the framework
+	  from which subsystems can access the energy models.
+
+	  The exact usage of the energy model is subsystem-dependent.
+
+	  If in doubt, say N.
diff --git a/kernel/power/Makefile b/kernel/power/Makefile
new file mode 100644
index 000000000..874ad834d
--- /dev/null
+++ b/kernel/power/Makefile
@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: GPL-2.0
+
+ifeq ($(CONFIG_DYNAMIC_DEBUG), y)
+CFLAGS_swap.o                   := -DDEBUG
+CFLAGS_snapshot.o               := -DDEBUG
+CFLAGS_energy_model.o           := -DDEBUG
+endif
+
+KASAN_SANITIZE_snapshot.o	:= n
+
+obj-y				+= qos.o
+obj-$(CONFIG_PM)		+= main.o
+obj-$(CONFIG_VT_CONSOLE_SLEEP)	+= console.o
+obj-$(CONFIG_FREEZER)		+= process.o
+obj-$(CONFIG_SUSPEND)		+= suspend.o
+obj-$(CONFIG_PM_TEST_SUSPEND)	+= suspend_test.o
+obj-$(CONFIG_HIBERNATION)	+= hibernate.o snapshot.o swap.o
+obj-$(CONFIG_HIBERNATION_SNAPSHOT_DEV) += user.o
+obj-$(CONFIG_PM_AUTOSLEEP)	+= autosleep.o
+obj-$(CONFIG_PM_WAKELOCKS)	+= wakelock.o
+
+obj-$(CONFIG_MAGIC_SYSRQ)	+= poweroff.o
+
+obj-$(CONFIG_ENERGY_MODEL)	+= energy_model.o
diff --git a/kernel/power/autosleep.c b/kernel/power/autosleep.c
new file mode 100644
index 000000000..b29c8aca7
--- /dev/null
+++ b/kernel/power/autosleep.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * kernel/power/autosleep.c
+ *
+ * Opportunistic sleep support.
+ *
+ * Copyright (C) 2012 Rafael J. Wysocki <rjw@sisk.pl>
+ */
+
+#include <linux/device.h>
+#include <linux/mutex.h>
+#include <linux/pm_wakeup.h>
+
+#include "power.h"
+
+static suspend_state_t autosleep_state;
+static struct workqueue_struct *autosleep_wq;
+/*
+ * Note: it is only safe to mutex_lock(&autosleep_lock) if a wakeup_source
+ * is active, otherwise a deadlock with try_to_suspend() is possible.
+ * Alternatively mutex_lock_interruptible() can be used.  This will then fail
+ * if an auto_sleep cycle tries to freeze processes.
+ */
+static DEFINE_MUTEX(autosleep_lock);
+static struct wakeup_source *autosleep_ws;
+
+static void try_to_suspend(struct work_struct *work)
+{
+	unsigned int initial_count, final_count;
+
+	if (!pm_get_wakeup_count(&initial_count, true))
+		goto out;
+
+	mutex_lock(&autosleep_lock);
+
+	if (!pm_save_wakeup_count(initial_count) ||
+		system_state != SYSTEM_RUNNING) {
+		mutex_unlock(&autosleep_lock);
+		goto out;
+	}
+
+	if (autosleep_state == PM_SUSPEND_ON) {
+		mutex_unlock(&autosleep_lock);
+		return;
+	}
+	if (autosleep_state >= PM_SUSPEND_MAX)
+		hibernate();
+	else
+		pm_suspend(autosleep_state);
+
+	mutex_unlock(&autosleep_lock);
+
+	if (!pm_get_wakeup_count(&final_count, false))
+		goto out;
+
+	/*
+	 * If the wakeup occurred for an unknown reason, wait to prevent the
+	 * system from trying to suspend and waking up in a tight loop.
+	 */
+	if (final_count == initial_count)
+		schedule_timeout_uninterruptible(HZ / 2);
+
+ out:
+	queue_up_suspend_work();
+}
+
+static DECLARE_WORK(suspend_work, try_to_suspend);
+
+void queue_up_suspend_work(void)
+{
+	if (autosleep_state > PM_SUSPEND_ON)
+		queue_work(autosleep_wq, &suspend_work);
+}
+
+suspend_state_t pm_autosleep_state(void)
+{
+	return autosleep_state;
+}
+
+int pm_autosleep_lock(void)
+{
+	return mutex_lock_interruptible(&autosleep_lock);
+}
+
+void pm_autosleep_unlock(void)
+{
+	mutex_unlock(&autosleep_lock);
+}
+
+int pm_autosleep_set_state(suspend_state_t state)
+{
+
+#ifndef CONFIG_HIBERNATION
+	if (state >= PM_SUSPEND_MAX)
+		return -EINVAL;
+#endif
+
+	__pm_stay_awake(autosleep_ws);
+
+	mutex_lock(&autosleep_lock);
+
+	autosleep_state = state;
+
+	__pm_relax(autosleep_ws);
+
+	if (state > PM_SUSPEND_ON) {
+		pm_wakep_autosleep_enabled(true);
+		queue_up_suspend_work();
+	} else {
+		pm_wakep_autosleep_enabled(false);
+	}
+
+	mutex_unlock(&autosleep_lock);
+	return 0;
+}
+
+int __init pm_autosleep_init(void)
+{
+	autosleep_ws = wakeup_source_register(NULL, "autosleep");
+	if (!autosleep_ws)
+		return -ENOMEM;
+
+	autosleep_wq = alloc_ordered_workqueue("autosleep", 0);
+	if (autosleep_wq)
+		return 0;
+
+	wakeup_source_unregister(autosleep_ws);
+	return -ENOMEM;
+}
diff --git a/kernel/power/console.c b/kernel/power/console.c
new file mode 100644
index 000000000..fcdf0e14a
--- /dev/null
+++ b/kernel/power/console.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions for saving/restoring console.
+ *
+ * Originally from swsusp.
+ */
+
+#include <linux/console.h>
+#include <linux/vt_kern.h>
+#include <linux/kbd_kern.h>
+#include <linux/vt.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include "power.h"
+
+#define SUSPEND_CONSOLE	(MAX_NR_CONSOLES-1)
+
+static int orig_fgconsole, orig_kmsg;
+
+static DEFINE_MUTEX(vt_switch_mutex);
+
+struct pm_vt_switch {
+	struct list_head head;
+	struct device *dev;
+	bool required;
+};
+
+static LIST_HEAD(pm_vt_switch_list);
+
+
+/**
+ * pm_vt_switch_required - indicate VT switch at suspend requirements
+ * @dev: device
+ * @required: if true, caller needs VT switch at suspend/resume time
+ *
+ * The different console drivers may or may not require VT switches across
+ * suspend/resume, depending on how they handle restoring video state and
+ * what may be running.
+ *
+ * Drivers can indicate support for switchless suspend/resume, which can
+ * save time and flicker, by using this routine and passing 'false' as
+ * the argument.  If any loaded driver needs VT switching, or the
+ * no_console_suspend argument has been passed on the command line, VT
+ * switches will occur.
+ */
+void pm_vt_switch_required(struct device *dev, bool required)
+{
+	struct pm_vt_switch *entry, *tmp;
+
+	mutex_lock(&vt_switch_mutex);
+	list_for_each_entry(tmp, &pm_vt_switch_list, head) {
+		if (tmp->dev == dev) {
+			/* already registered, update requirement */
+			tmp->required = required;
+			goto out;
+		}
+	}
+
+	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+	if (!entry)
+		goto out;
+
+	entry->required = required;
+	entry->dev = dev;
+
+	list_add(&entry->head, &pm_vt_switch_list);
+out:
+	mutex_unlock(&vt_switch_mutex);
+}
+EXPORT_SYMBOL(pm_vt_switch_required);
+
+/**
+ * pm_vt_switch_unregister - stop tracking a device's VT switching needs
+ * @dev: device
+ *
+ * Remove @dev from the vt switch list.
+ */
+void pm_vt_switch_unregister(struct device *dev)
+{
+	struct pm_vt_switch *tmp;
+
+	mutex_lock(&vt_switch_mutex);
+	list_for_each_entry(tmp, &pm_vt_switch_list, head) {
+		if (tmp->dev == dev) {
+			list_del(&tmp->head);
+			kfree(tmp);
+			break;
+		}
+	}
+	mutex_unlock(&vt_switch_mutex);
+}
+EXPORT_SYMBOL(pm_vt_switch_unregister);
+
+/*
+ * There are three cases when a VT switch on suspend/resume are required:
+ *   1) no driver has indicated a requirement one way or another, so preserve
+ *      the old behavior
+ *   2) console suspend is disabled, we want to see debug messages across
+ *      suspend/resume
+ *   3) any registered driver indicates it needs a VT switch
+ *
+ * If none of these conditions is present, meaning we have at least one driver
+ * that doesn't need the switch, and none that do, we can avoid it to make
+ * resume look a little prettier (and suspend too, but that's usually hidden,
+ * e.g. when closing the lid on a laptop).
+ */
+static bool pm_vt_switch(void)
+{
+	struct pm_vt_switch *entry;
+	bool ret = true;
+
+	mutex_lock(&vt_switch_mutex);
+	if (list_empty(&pm_vt_switch_list))
+		goto out;
+
+	if (!console_suspend_enabled)
+		goto out;
+
+	list_for_each_entry(entry, &pm_vt_switch_list, head) {
+		if (entry->required)
+			goto out;
+	}
+
+	ret = false;
+out:
+	mutex_unlock(&vt_switch_mutex);
+	return ret;
+}
+
+void pm_prepare_console(void)
+{
+	if (!pm_vt_switch())
+		return;
+
+	orig_fgconsole = vt_move_to_console(SUSPEND_CONSOLE, 1);
+	if (orig_fgconsole < 0)
+		return;
+
+	orig_kmsg = vt_kmsg_redirect(SUSPEND_CONSOLE);
+	return;
+}
+
+void pm_restore_console(void)
+{
+	if (!pm_vt_switch())
+		return;
+
+	if (orig_fgconsole >= 0) {
+		vt_move_to_console(orig_fgconsole, 0);
+		vt_kmsg_redirect(orig_kmsg);
+	}
+}
diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c
new file mode 100644
index 000000000..7b44f5b89
--- /dev/null
+++ b/kernel/power/energy_model.c
@@ -0,0 +1,438 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Energy Model of devices
+ *
+ * Copyright (c) 2018-2021, Arm ltd.
+ * Written by: Quentin Perret, Arm ltd.
+ * Improvements provided by: Lukasz Luba, Arm ltd.
+ */
+
+#define pr_fmt(fmt) "energy_model: " fmt
+
+#include <linux/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/cpumask.h>
+#include <linux/debugfs.h>
+#include <linux/energy_model.h>
+#include <linux/sched/topology.h>
+#include <linux/slab.h>
+
+/*
+ * Mutex serializing the registrations of performance domains and letting
+ * callbacks defined by drivers sleep.
+ */
+static DEFINE_MUTEX(em_pd_mutex);
+
+static bool _is_cpu_device(struct device *dev)
+{
+	return (dev->bus == &cpu_subsys);
+}
+
+#ifdef CONFIG_DEBUG_FS
+static struct dentry *rootdir;
+
+static void em_debug_create_ps(struct em_perf_state *ps, struct dentry *pd)
+{
+	struct dentry *d;
+	char name[24];
+
+	snprintf(name, sizeof(name), "ps:%lu", ps->frequency);
+
+	/* Create per-ps directory */
+	d = debugfs_create_dir(name, pd);
+	debugfs_create_ulong("frequency", 0444, d, &ps->frequency);
+	debugfs_create_ulong("power", 0444, d, &ps->power);
+	debugfs_create_ulong("cost", 0444, d, &ps->cost);
+	debugfs_create_ulong("inefficient", 0444, d, &ps->flags);
+}
+
+static int em_debug_cpus_show(struct seq_file *s, void *unused)
+{
+	seq_printf(s, "%*pbl\n", cpumask_pr_args(to_cpumask(s->private)));
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(em_debug_cpus);
+
+static int em_debug_flags_show(struct seq_file *s, void *unused)
+{
+	struct em_perf_domain *pd = s->private;
+
+	seq_printf(s, "%#lx\n", pd->flags);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(em_debug_flags);
+
+static void em_debug_create_pd(struct device *dev)
+{
+	struct dentry *d;
+	int i;
+
+	/* Create the directory of the performance domain */
+	d = debugfs_create_dir(dev_name(dev), rootdir);
+
+	if (_is_cpu_device(dev))
+		debugfs_create_file("cpus", 0444, d, dev->em_pd->cpus,
+				    &em_debug_cpus_fops);
+
+	debugfs_create_file("flags", 0444, d, dev->em_pd,
+			    &em_debug_flags_fops);
+
+	/* Create a sub-directory for each performance state */
+	for (i = 0; i < dev->em_pd->nr_perf_states; i++)
+		em_debug_create_ps(&dev->em_pd->table[i], d);
+
+}
+
+static void em_debug_remove_pd(struct device *dev)
+{
+	debugfs_lookup_and_remove(dev_name(dev), rootdir);
+}
+
+static int __init em_debug_init(void)
+{
+	/* Create /sys/kernel/debug/energy_model directory */
+	rootdir = debugfs_create_dir("energy_model", NULL);
+
+	return 0;
+}
+fs_initcall(em_debug_init);
+#else /* CONFIG_DEBUG_FS */
+static void em_debug_create_pd(struct device *dev) {}
+static void em_debug_remove_pd(struct device *dev) {}
+#endif
+
+static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd,
+				int nr_states, struct em_data_callback *cb,
+				unsigned long flags)
+{
+	unsigned long power, freq, prev_freq = 0, prev_cost = ULONG_MAX;
+	struct em_perf_state *table;
+	int i, ret;
+	u64 fmax;
+
+	table = kcalloc(nr_states, sizeof(*table), GFP_KERNEL);
+	if (!table)
+		return -ENOMEM;
+
+	/* Build the list of performance states for this performance domain */
+	for (i = 0, freq = 0; i < nr_states; i++, freq++) {
+		/*
+		 * active_power() is a driver callback which ceils 'freq' to
+		 * lowest performance state of 'dev' above 'freq' and updates
+		 * 'power' and 'freq' accordingly.
+		 */
+		ret = cb->active_power(dev, &power, &freq);
+		if (ret) {
+			dev_err(dev, "EM: invalid perf. state: %d\n",
+				ret);
+			goto free_ps_table;
+		}
+
+		/*
+		 * We expect the driver callback to increase the frequency for
+		 * higher performance states.
+		 */
+		if (freq <= prev_freq) {
+			dev_err(dev, "EM: non-increasing freq: %lu\n",
+				freq);
+			goto free_ps_table;
+		}
+
+		/*
+		 * The power returned by active_state() is expected to be
+		 * positive and be in range.
+		 */
+		if (!power || power > EM_MAX_POWER) {
+			dev_err(dev, "EM: invalid power: %lu\n",
+				power);
+			goto free_ps_table;
+		}
+
+		table[i].power = power;
+		table[i].frequency = prev_freq = freq;
+	}
+
+	/* Compute the cost of each performance state. */
+	fmax = (u64) table[nr_states - 1].frequency;
+	for (i = nr_states - 1; i >= 0; i--) {
+		unsigned long power_res, cost;
+
+		if (flags & EM_PERF_DOMAIN_ARTIFICIAL) {
+			ret = cb->get_cost(dev, table[i].frequency, &cost);
+			if (ret || !cost || cost > EM_MAX_POWER) {
+				dev_err(dev, "EM: invalid cost %lu %d\n",
+					cost, ret);
+				goto free_ps_table;
+			}
+		} else {
+			power_res = table[i].power;
+			cost = div64_u64(fmax * power_res, table[i].frequency);
+		}
+
+		table[i].cost = cost;
+
+		if (table[i].cost >= prev_cost) {
+			table[i].flags = EM_PERF_STATE_INEFFICIENT;
+			dev_dbg(dev, "EM: OPP:%lu is inefficient\n",
+				table[i].frequency);
+		} else {
+			prev_cost = table[i].cost;
+		}
+	}
+
+	pd->table = table;
+	pd->nr_perf_states = nr_states;
+
+	return 0;
+
+free_ps_table:
+	kfree(table);
+	return -EINVAL;
+}
+
+static int em_create_pd(struct device *dev, int nr_states,
+			struct em_data_callback *cb, cpumask_t *cpus,
+			unsigned long flags)
+{
+	struct em_perf_domain *pd;
+	struct device *cpu_dev;
+	int cpu, ret, num_cpus;
+
+	if (_is_cpu_device(dev)) {
+		num_cpus = cpumask_weight(cpus);
+
+		/* Prevent max possible energy calculation to not overflow */
+		if (num_cpus > EM_MAX_NUM_CPUS) {
+			dev_err(dev, "EM: too many CPUs, overflow possible\n");
+			return -EINVAL;
+		}
+
+		pd = kzalloc(sizeof(*pd) + cpumask_size(), GFP_KERNEL);
+		if (!pd)
+			return -ENOMEM;
+
+		cpumask_copy(em_span_cpus(pd), cpus);
+	} else {
+		pd = kzalloc(sizeof(*pd), GFP_KERNEL);
+		if (!pd)
+			return -ENOMEM;
+	}
+
+	ret = em_create_perf_table(dev, pd, nr_states, cb, flags);
+	if (ret) {
+		kfree(pd);
+		return ret;
+	}
+
+	if (_is_cpu_device(dev))
+		for_each_cpu(cpu, cpus) {
+			cpu_dev = get_cpu_device(cpu);
+			cpu_dev->em_pd = pd;
+		}
+
+	dev->em_pd = pd;
+
+	return 0;
+}
+
+static void em_cpufreq_update_efficiencies(struct device *dev)
+{
+	struct em_perf_domain *pd = dev->em_pd;
+	struct em_perf_state *table;
+	struct cpufreq_policy *policy;
+	int found = 0;
+	int i;
+
+	if (!_is_cpu_device(dev) || !pd)
+		return;
+
+	policy = cpufreq_cpu_get(cpumask_first(em_span_cpus(pd)));
+	if (!policy) {
+		dev_warn(dev, "EM: Access to CPUFreq policy failed");
+		return;
+	}
+
+	table = pd->table;
+
+	for (i = 0; i < pd->nr_perf_states; i++) {
+		if (!(table[i].flags & EM_PERF_STATE_INEFFICIENT))
+			continue;
+
+		if (!cpufreq_table_set_inefficient(policy, table[i].frequency))
+			found++;
+	}
+
+	cpufreq_cpu_put(policy);
+
+	if (!found)
+		return;
+
+	/*
+	 * Efficiencies have been installed in CPUFreq, inefficient frequencies
+	 * will be skipped. The EM can do the same.
+	 */
+	pd->flags |= EM_PERF_DOMAIN_SKIP_INEFFICIENCIES;
+}
+
+/**
+ * em_pd_get() - Return the performance domain for a device
+ * @dev : Device to find the performance domain for
+ *
+ * Returns the performance domain to which @dev belongs, or NULL if it doesn't
+ * exist.
+ */
+struct em_perf_domain *em_pd_get(struct device *dev)
+{
+	if (IS_ERR_OR_NULL(dev))
+		return NULL;
+
+	return dev->em_pd;
+}
+EXPORT_SYMBOL_GPL(em_pd_get);
+
+/**
+ * em_cpu_get() - Return the performance domain for a CPU
+ * @cpu : CPU to find the performance domain for
+ *
+ * Returns the performance domain to which @cpu belongs, or NULL if it doesn't
+ * exist.
+ */
+struct em_perf_domain *em_cpu_get(int cpu)
+{
+	struct device *cpu_dev;
+
+	cpu_dev = get_cpu_device(cpu);
+	if (!cpu_dev)
+		return NULL;
+
+	return em_pd_get(cpu_dev);
+}
+EXPORT_SYMBOL_GPL(em_cpu_get);
+
+/**
+ * em_dev_register_perf_domain() - Register the Energy Model (EM) for a device
+ * @dev		: Device for which the EM is to register
+ * @nr_states	: Number of performance states to register
+ * @cb		: Callback functions providing the data of the Energy Model
+ * @cpus	: Pointer to cpumask_t, which in case of a CPU device is
+ *		obligatory. It can be taken from i.e. 'policy->cpus'. For other
+ *		type of devices this should be set to NULL.
+ * @microwatts	: Flag indicating that the power values are in micro-Watts or
+ *		in some other scale. It must be set properly.
+ *
+ * Create Energy Model tables for a performance domain using the callbacks
+ * defined in cb.
+ *
+ * The @microwatts is important to set with correct value. Some kernel
+ * sub-systems might rely on this flag and check if all devices in the EM are
+ * using the same scale.
+ *
+ * If multiple clients register the same performance domain, all but the first
+ * registration will be ignored.
+ *
+ * Return 0 on success
+ */
+int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states,
+				struct em_data_callback *cb, cpumask_t *cpus,
+				bool microwatts)
+{
+	unsigned long cap, prev_cap = 0;
+	unsigned long flags = 0;
+	int cpu, ret;
+
+	if (!dev || !nr_states || !cb)
+		return -EINVAL;
+
+	/*
+	 * Use a mutex to serialize the registration of performance domains and
+	 * let the driver-defined callback functions sleep.
+	 */
+	mutex_lock(&em_pd_mutex);
+
+	if (dev->em_pd) {
+		ret = -EEXIST;
+		goto unlock;
+	}
+
+	if (_is_cpu_device(dev)) {
+		if (!cpus) {
+			dev_err(dev, "EM: invalid CPU mask\n");
+			ret = -EINVAL;
+			goto unlock;
+		}
+
+		for_each_cpu(cpu, cpus) {
+			if (em_cpu_get(cpu)) {
+				dev_err(dev, "EM: exists for CPU%d\n", cpu);
+				ret = -EEXIST;
+				goto unlock;
+			}
+			/*
+			 * All CPUs of a domain must have the same
+			 * micro-architecture since they all share the same
+			 * table.
+			 */
+			cap = arch_scale_cpu_capacity(cpu);
+			if (prev_cap && prev_cap != cap) {
+				dev_err(dev, "EM: CPUs of %*pbl must have the same capacity\n",
+					cpumask_pr_args(cpus));
+
+				ret = -EINVAL;
+				goto unlock;
+			}
+			prev_cap = cap;
+		}
+	}
+
+	if (microwatts)
+		flags |= EM_PERF_DOMAIN_MICROWATTS;
+	else if (cb->get_cost)
+		flags |= EM_PERF_DOMAIN_ARTIFICIAL;
+
+	ret = em_create_pd(dev, nr_states, cb, cpus, flags);
+	if (ret)
+		goto unlock;
+
+	dev->em_pd->flags |= flags;
+
+	em_cpufreq_update_efficiencies(dev);
+
+	em_debug_create_pd(dev);
+	dev_info(dev, "EM: created perf domain\n");
+
+unlock:
+	mutex_unlock(&em_pd_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(em_dev_register_perf_domain);
+
+/**
+ * em_dev_unregister_perf_domain() - Unregister Energy Model (EM) for a device
+ * @dev		: Device for which the EM is registered
+ *
+ * Unregister the EM for the specified @dev (but not a CPU device).
+ */
+void em_dev_unregister_perf_domain(struct device *dev)
+{
+	if (IS_ERR_OR_NULL(dev) || !dev->em_pd)
+		return;
+
+	if (_is_cpu_device(dev))
+		return;
+
+	/*
+	 * The mutex separates all register/unregister requests and protects
+	 * from potential clean-up/setup issues in the debugfs directories.
+	 * The debugfs directory name is the same as device's name.
+	 */
+	mutex_lock(&em_pd_mutex);
+	em_debug_remove_pd(dev);
+
+	kfree(dev->em_pd->table);
+	kfree(dev->em_pd);
+	dev->em_pd = NULL;
+	mutex_unlock(&em_pd_mutex);
+}
+EXPORT_SYMBOL_GPL(em_dev_unregister_perf_domain);
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
new file mode 100644
index 000000000..8d35b9f9a
--- /dev/null
+++ b/kernel/power/hibernate.c
@@ -0,0 +1,1373 @@
+// 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/blkdev.h>
+#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;
+
+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(bool snapshot_test)
+{
+	int error;
+	unsigned int flags;
+
+	pm_pr_dbg("Loading hibernation image.\n");
+
+	lock_device_hotplug();
+	error = create_basic_memory_bitmaps();
+	if (error) {
+		swsusp_close(snapshot_test);
+		goto Unlock;
+	}
+
+	error = swsusp_read(&flags);
+	swsusp_close(snapshot_test);
+	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)
+{
+	bool snapshot_test = false;
+	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;
+
+	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(false);
+		if (!error)
+			error = load_image_and_restore(false);
+	}
+	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);
+
+static int __init find_resume_device(void)
+{
+	if (!strlen(resume_file))
+		return -ENOENT;
+
+	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 */
+	if (!early_lookup_bdev(resume_file, &swsusp_resume_device))
+		return 0;
+
+	/*
+	 * Some device discovery might still be in progress; we need to wait for
+	 * this to finish.
+	 */
+	wait_for_device_probe();
+	if (resume_wait) {
+		while (early_lookup_bdev(resume_file, &swsusp_resume_device))
+			msleep(10);
+		async_synchronize_full();
+	}
+
+	return early_lookup_bdev(resume_file, &swsusp_resume_device);
+}
+
+static int software_resume(void)
+{
+	int error;
+
+	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");
+
+	mutex_lock(&system_transition_mutex);
+	error = swsusp_check(true);
+	if (error)
+		goto Unlock;
+
+	/* The snapshot device should not be opened while we're running */
+	if (!hibernate_acquire()) {
+		error = -EBUSY;
+		swsusp_close(true);
+		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(true);
+	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(true);
+	goto Finish;
+}
+
+/**
+ * software_resume_initcall - 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 __init software_resume_initcall(void)
+{
+	/*
+	 * If the user said "noresume".. bail out early.
+	 */
+	if (noresume || !hibernation_available())
+		return 0;
+
+	if (!swsusp_resume_device) {
+		int error = find_resume_device();
+
+		if (error)
+			return error;
+	}
+
+	return software_resume();
+}
+late_initcall_sync(software_resume_initcall);
+
+
+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 dev;
+	int error;
+
+	if (!hibernation_available())
+		return n;
+
+	if (len && buf[len-1] == '\n')
+		len--;
+	name = kstrndup(buf, len, GFP_KERNEL);
+	if (!name)
+		return -ENOMEM;
+
+	error = lookup_bdev(name, &dev);
+	if (error) {
+		unsigned maj, min, offset;
+		char *p, dummy;
+
+		error = 0;
+		if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 ||
+		    sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset,
+				&dummy) == 3) {
+			dev = MKDEV(maj, min);
+			if (maj != MAJOR(dev) || min != MINOR(dev))
+				error = -EINVAL;
+		} else {
+			dev = new_decode_dev(simple_strtoul(name, &p, 16));
+			if (*p)
+				error = -EINVAL;
+		}
+	}
+	kfree(name);
+	if (error)
+		return error;
+
+	sleep_flags = lock_system_sleep();
+	swsusp_resume_device = dev;
+	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);
diff --git a/kernel/power/main.c b/kernel/power/main.c
new file mode 100644
index 000000000..f6425ae3e
--- /dev/null
+++ b/kernel/power/main.c
@@ -0,0 +1,1008 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * kernel/power/main.c - PM subsystem core functionality.
+ *
+ * Copyright (c) 2003 Patrick Mochel
+ * Copyright (c) 2003 Open Source Development Lab
+ */
+
+#include <linux/acpi.h>
+#include <linux/export.h>
+#include <linux/kobject.h>
+#include <linux/string.h>
+#include <linux/pm-trace.h>
+#include <linux/workqueue.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/suspend.h>
+#include <linux/syscalls.h>
+#include <linux/pm_runtime.h>
+
+#include "power.h"
+
+#ifdef CONFIG_PM_SLEEP
+/*
+ * The following functions are used by the suspend/hibernate code to temporarily
+ * change gfp_allowed_mask in order to avoid using I/O during memory allocations
+ * while devices are suspended.  To avoid races with the suspend/hibernate code,
+ * they should always be called with system_transition_mutex held
+ * (gfp_allowed_mask also should only be modified with system_transition_mutex
+ * held, unless the suspend/hibernate code is guaranteed not to run in parallel
+ * with that modification).
+ */
+static gfp_t saved_gfp_mask;
+
+void pm_restore_gfp_mask(void)
+{
+	WARN_ON(!mutex_is_locked(&system_transition_mutex));
+	if (saved_gfp_mask) {
+		gfp_allowed_mask = saved_gfp_mask;
+		saved_gfp_mask = 0;
+	}
+}
+
+void pm_restrict_gfp_mask(void)
+{
+	WARN_ON(!mutex_is_locked(&system_transition_mutex));
+	WARN_ON(saved_gfp_mask);
+	saved_gfp_mask = gfp_allowed_mask;
+	gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS);
+}
+
+unsigned int lock_system_sleep(void)
+{
+	unsigned int flags = current->flags;
+	current->flags |= PF_NOFREEZE;
+	mutex_lock(&system_transition_mutex);
+	return flags;
+}
+EXPORT_SYMBOL_GPL(lock_system_sleep);
+
+void unlock_system_sleep(unsigned int flags)
+{
+	/*
+	 * Don't use freezer_count() because we don't want the call to
+	 * try_to_freeze() here.
+	 *
+	 * Reason:
+	 * Fundamentally, we just don't need it, because freezing condition
+	 * doesn't come into effect until we release the
+	 * system_transition_mutex lock, since the freezer always works with
+	 * system_transition_mutex held.
+	 *
+	 * More importantly, in the case of hibernation,
+	 * unlock_system_sleep() gets called in snapshot_read() and
+	 * snapshot_write() when the freezing condition is still in effect.
+	 * Which means, if we use try_to_freeze() here, it would make them
+	 * enter the refrigerator, thus causing hibernation to lockup.
+	 */
+	if (!(flags & PF_NOFREEZE))
+		current->flags &= ~PF_NOFREEZE;
+	mutex_unlock(&system_transition_mutex);
+}
+EXPORT_SYMBOL_GPL(unlock_system_sleep);
+
+void ksys_sync_helper(void)
+{
+	ktime_t start;
+	long elapsed_msecs;
+
+	start = ktime_get();
+	ksys_sync();
+	elapsed_msecs = ktime_to_ms(ktime_sub(ktime_get(), start));
+	pr_info("Filesystems sync: %ld.%03ld seconds\n",
+		elapsed_msecs / MSEC_PER_SEC, elapsed_msecs % MSEC_PER_SEC);
+}
+EXPORT_SYMBOL_GPL(ksys_sync_helper);
+
+/* Routines for PM-transition notifications */
+
+static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
+
+int register_pm_notifier(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&pm_chain_head, nb);
+}
+EXPORT_SYMBOL_GPL(register_pm_notifier);
+
+int unregister_pm_notifier(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&pm_chain_head, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_pm_notifier);
+
+void pm_report_hw_sleep_time(u64 t)
+{
+	suspend_stats.last_hw_sleep = t;
+	suspend_stats.total_hw_sleep += t;
+}
+EXPORT_SYMBOL_GPL(pm_report_hw_sleep_time);
+
+void pm_report_max_hw_sleep(u64 t)
+{
+	suspend_stats.max_hw_sleep = t;
+}
+EXPORT_SYMBOL_GPL(pm_report_max_hw_sleep);
+
+int pm_notifier_call_chain_robust(unsigned long val_up, unsigned long val_down)
+{
+	int ret;
+
+	ret = blocking_notifier_call_chain_robust(&pm_chain_head, val_up, val_down, NULL);
+
+	return notifier_to_errno(ret);
+}
+
+int pm_notifier_call_chain(unsigned long val)
+{
+	return blocking_notifier_call_chain(&pm_chain_head, val, NULL);
+}
+
+/* If set, devices may be suspended and resumed asynchronously. */
+int pm_async_enabled = 1;
+
+static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
+			     char *buf)
+{
+	return sprintf(buf, "%d\n", pm_async_enabled);
+}
+
+static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
+			      const char *buf, size_t n)
+{
+	unsigned long val;
+
+	if (kstrtoul(buf, 10, &val))
+		return -EINVAL;
+
+	if (val > 1)
+		return -EINVAL;
+
+	pm_async_enabled = val;
+	return n;
+}
+
+power_attr(pm_async);
+
+#ifdef CONFIG_SUSPEND
+static ssize_t mem_sleep_show(struct kobject *kobj, struct kobj_attribute *attr,
+			      char *buf)
+{
+	char *s = buf;
+	suspend_state_t i;
+
+	for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++) {
+		if (i >= PM_SUSPEND_MEM && cxl_mem_active())
+			continue;
+		if (mem_sleep_states[i]) {
+			const char *label = mem_sleep_states[i];
+
+			if (mem_sleep_current == i)
+				s += sprintf(s, "[%s] ", label);
+			else
+				s += sprintf(s, "%s ", label);
+		}
+	}
+
+	/* Convert the last space to a newline if needed. */
+	if (s != buf)
+		*(s-1) = '\n';
+
+	return (s - buf);
+}
+
+static suspend_state_t decode_suspend_state(const char *buf, size_t n)
+{
+	suspend_state_t state;
+	char *p;
+	int len;
+
+	p = memchr(buf, '\n', n);
+	len = p ? p - buf : n;
+
+	for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
+		const char *label = mem_sleep_states[state];
+
+		if (label && len == strlen(label) && !strncmp(buf, label, len))
+			return state;
+	}
+
+	return PM_SUSPEND_ON;
+}
+
+static ssize_t mem_sleep_store(struct kobject *kobj, struct kobj_attribute *attr,
+			       const char *buf, size_t n)
+{
+	suspend_state_t state;
+	int error;
+
+	error = pm_autosleep_lock();
+	if (error)
+		return error;
+
+	if (pm_autosleep_state() > PM_SUSPEND_ON) {
+		error = -EBUSY;
+		goto out;
+	}
+
+	state = decode_suspend_state(buf, n);
+	if (state < PM_SUSPEND_MAX && state > PM_SUSPEND_ON)
+		mem_sleep_current = state;
+	else
+		error = -EINVAL;
+
+ out:
+	pm_autosleep_unlock();
+	return error ? error : n;
+}
+
+power_attr(mem_sleep);
+
+/*
+ * sync_on_suspend: invoke ksys_sync_helper() before suspend.
+ *
+ * show() returns whether ksys_sync_helper() is invoked before suspend.
+ * store() accepts 0 or 1.  0 disables ksys_sync_helper() and 1 enables it.
+ */
+bool sync_on_suspend_enabled = !IS_ENABLED(CONFIG_SUSPEND_SKIP_SYNC);
+
+static ssize_t sync_on_suspend_show(struct kobject *kobj,
+				   struct kobj_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", sync_on_suspend_enabled);
+}
+
+static ssize_t sync_on_suspend_store(struct kobject *kobj,
+				    struct kobj_attribute *attr,
+				    const char *buf, size_t n)
+{
+	unsigned long val;
+
+	if (kstrtoul(buf, 10, &val))
+		return -EINVAL;
+
+	if (val > 1)
+		return -EINVAL;
+
+	sync_on_suspend_enabled = !!val;
+	return n;
+}
+
+power_attr(sync_on_suspend);
+#endif /* CONFIG_SUSPEND */
+
+#ifdef CONFIG_PM_SLEEP_DEBUG
+int pm_test_level = TEST_NONE;
+
+static const char * const pm_tests[__TEST_AFTER_LAST] = {
+	[TEST_NONE] = "none",
+	[TEST_CORE] = "core",
+	[TEST_CPUS] = "processors",
+	[TEST_PLATFORM] = "platform",
+	[TEST_DEVICES] = "devices",
+	[TEST_FREEZER] = "freezer",
+};
+
+static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
+				char *buf)
+{
+	char *s = buf;
+	int level;
+
+	for (level = TEST_FIRST; level <= TEST_MAX; level++)
+		if (pm_tests[level]) {
+			if (level == pm_test_level)
+				s += sprintf(s, "[%s] ", pm_tests[level]);
+			else
+				s += sprintf(s, "%s ", pm_tests[level]);
+		}
+
+	if (s != buf)
+		/* convert the last space to a newline */
+		*(s-1) = '\n';
+
+	return (s - buf);
+}
+
+static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
+				const char *buf, size_t n)
+{
+	unsigned int sleep_flags;
+	const char * const *s;
+	int error = -EINVAL;
+	int level;
+	char *p;
+	int len;
+
+	p = memchr(buf, '\n', n);
+	len = p ? p - buf : n;
+
+	sleep_flags = lock_system_sleep();
+
+	level = TEST_FIRST;
+	for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
+		if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
+			pm_test_level = level;
+			error = 0;
+			break;
+		}
+
+	unlock_system_sleep(sleep_flags);
+
+	return error ? error : n;
+}
+
+power_attr(pm_test);
+#endif /* CONFIG_PM_SLEEP_DEBUG */
+
+static char *suspend_step_name(enum suspend_stat_step step)
+{
+	switch (step) {
+	case SUSPEND_FREEZE:
+		return "freeze";
+	case SUSPEND_PREPARE:
+		return "prepare";
+	case SUSPEND_SUSPEND:
+		return "suspend";
+	case SUSPEND_SUSPEND_NOIRQ:
+		return "suspend_noirq";
+	case SUSPEND_RESUME_NOIRQ:
+		return "resume_noirq";
+	case SUSPEND_RESUME:
+		return "resume";
+	default:
+		return "";
+	}
+}
+
+#define suspend_attr(_name, format_str)				\
+static ssize_t _name##_show(struct kobject *kobj,		\
+		struct kobj_attribute *attr, char *buf)		\
+{								\
+	return sprintf(buf, format_str, suspend_stats._name);	\
+}								\
+static struct kobj_attribute _name = __ATTR_RO(_name)
+
+suspend_attr(success, "%d\n");
+suspend_attr(fail, "%d\n");
+suspend_attr(failed_freeze, "%d\n");
+suspend_attr(failed_prepare, "%d\n");
+suspend_attr(failed_suspend, "%d\n");
+suspend_attr(failed_suspend_late, "%d\n");
+suspend_attr(failed_suspend_noirq, "%d\n");
+suspend_attr(failed_resume, "%d\n");
+suspend_attr(failed_resume_early, "%d\n");
+suspend_attr(failed_resume_noirq, "%d\n");
+suspend_attr(last_hw_sleep, "%llu\n");
+suspend_attr(total_hw_sleep, "%llu\n");
+suspend_attr(max_hw_sleep, "%llu\n");
+
+static ssize_t last_failed_dev_show(struct kobject *kobj,
+		struct kobj_attribute *attr, char *buf)
+{
+	int index;
+	char *last_failed_dev = NULL;
+
+	index = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
+	index %= REC_FAILED_NUM;
+	last_failed_dev = suspend_stats.failed_devs[index];
+
+	return sprintf(buf, "%s\n", last_failed_dev);
+}
+static struct kobj_attribute last_failed_dev = __ATTR_RO(last_failed_dev);
+
+static ssize_t last_failed_errno_show(struct kobject *kobj,
+		struct kobj_attribute *attr, char *buf)
+{
+	int index;
+	int last_failed_errno;
+
+	index = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
+	index %= REC_FAILED_NUM;
+	last_failed_errno = suspend_stats.errno[index];
+
+	return sprintf(buf, "%d\n", last_failed_errno);
+}
+static struct kobj_attribute last_failed_errno = __ATTR_RO(last_failed_errno);
+
+static ssize_t last_failed_step_show(struct kobject *kobj,
+		struct kobj_attribute *attr, char *buf)
+{
+	int index;
+	enum suspend_stat_step step;
+	char *last_failed_step = NULL;
+
+	index = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
+	index %= REC_FAILED_NUM;
+	step = suspend_stats.failed_steps[index];
+	last_failed_step = suspend_step_name(step);
+
+	return sprintf(buf, "%s\n", last_failed_step);
+}
+static struct kobj_attribute last_failed_step = __ATTR_RO(last_failed_step);
+
+static struct attribute *suspend_attrs[] = {
+	&success.attr,
+	&fail.attr,
+	&failed_freeze.attr,
+	&failed_prepare.attr,
+	&failed_suspend.attr,
+	&failed_suspend_late.attr,
+	&failed_suspend_noirq.attr,
+	&failed_resume.attr,
+	&failed_resume_early.attr,
+	&failed_resume_noirq.attr,
+	&last_failed_dev.attr,
+	&last_failed_errno.attr,
+	&last_failed_step.attr,
+	&last_hw_sleep.attr,
+	&total_hw_sleep.attr,
+	&max_hw_sleep.attr,
+	NULL,
+};
+
+static umode_t suspend_attr_is_visible(struct kobject *kobj, struct attribute *attr, int idx)
+{
+	if (attr != &last_hw_sleep.attr &&
+	    attr != &total_hw_sleep.attr &&
+	    attr != &max_hw_sleep.attr)
+		return 0444;
+
+#ifdef CONFIG_ACPI
+	if (acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0)
+		return 0444;
+#endif
+	return 0;
+}
+
+static const struct attribute_group suspend_attr_group = {
+	.name = "suspend_stats",
+	.attrs = suspend_attrs,
+	.is_visible = suspend_attr_is_visible,
+};
+
+#ifdef CONFIG_DEBUG_FS
+static int suspend_stats_show(struct seq_file *s, void *unused)
+{
+	int i, index, last_dev, last_errno, last_step;
+
+	last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
+	last_dev %= REC_FAILED_NUM;
+	last_errno = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
+	last_errno %= REC_FAILED_NUM;
+	last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
+	last_step %= REC_FAILED_NUM;
+	seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
+			"%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
+			"success", suspend_stats.success,
+			"fail", suspend_stats.fail,
+			"failed_freeze", suspend_stats.failed_freeze,
+			"failed_prepare", suspend_stats.failed_prepare,
+			"failed_suspend", suspend_stats.failed_suspend,
+			"failed_suspend_late",
+				suspend_stats.failed_suspend_late,
+			"failed_suspend_noirq",
+				suspend_stats.failed_suspend_noirq,
+			"failed_resume", suspend_stats.failed_resume,
+			"failed_resume_early",
+				suspend_stats.failed_resume_early,
+			"failed_resume_noirq",
+				suspend_stats.failed_resume_noirq);
+	seq_printf(s,	"failures:\n  last_failed_dev:\t%-s\n",
+			suspend_stats.failed_devs[last_dev]);
+	for (i = 1; i < REC_FAILED_NUM; i++) {
+		index = last_dev + REC_FAILED_NUM - i;
+		index %= REC_FAILED_NUM;
+		seq_printf(s, "\t\t\t%-s\n",
+			suspend_stats.failed_devs[index]);
+	}
+	seq_printf(s,	"  last_failed_errno:\t%-d\n",
+			suspend_stats.errno[last_errno]);
+	for (i = 1; i < REC_FAILED_NUM; i++) {
+		index = last_errno + REC_FAILED_NUM - i;
+		index %= REC_FAILED_NUM;
+		seq_printf(s, "\t\t\t%-d\n",
+			suspend_stats.errno[index]);
+	}
+	seq_printf(s,	"  last_failed_step:\t%-s\n",
+			suspend_step_name(
+				suspend_stats.failed_steps[last_step]));
+	for (i = 1; i < REC_FAILED_NUM; i++) {
+		index = last_step + REC_FAILED_NUM - i;
+		index %= REC_FAILED_NUM;
+		seq_printf(s, "\t\t\t%-s\n",
+			suspend_step_name(
+				suspend_stats.failed_steps[index]));
+	}
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(suspend_stats);
+
+static int __init pm_debugfs_init(void)
+{
+	debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,
+			NULL, NULL, &suspend_stats_fops);
+	return 0;
+}
+
+late_initcall(pm_debugfs_init);
+#endif /* CONFIG_DEBUG_FS */
+
+#endif /* CONFIG_PM_SLEEP */
+
+#ifdef CONFIG_PM_SLEEP_DEBUG
+/*
+ * pm_print_times: print time taken by devices to suspend and resume.
+ *
+ * show() returns whether printing of suspend and resume times is enabled.
+ * store() accepts 0 or 1.  0 disables printing and 1 enables it.
+ */
+bool pm_print_times_enabled;
+
+static ssize_t pm_print_times_show(struct kobject *kobj,
+				   struct kobj_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", pm_print_times_enabled);
+}
+
+static ssize_t pm_print_times_store(struct kobject *kobj,
+				    struct kobj_attribute *attr,
+				    const char *buf, size_t n)
+{
+	unsigned long val;
+
+	if (kstrtoul(buf, 10, &val))
+		return -EINVAL;
+
+	if (val > 1)
+		return -EINVAL;
+
+	pm_print_times_enabled = !!val;
+	return n;
+}
+
+power_attr(pm_print_times);
+
+static inline void pm_print_times_init(void)
+{
+	pm_print_times_enabled = !!initcall_debug;
+}
+
+static ssize_t pm_wakeup_irq_show(struct kobject *kobj,
+					struct kobj_attribute *attr,
+					char *buf)
+{
+	if (!pm_wakeup_irq())
+		return -ENODATA;
+
+	return sprintf(buf, "%u\n", pm_wakeup_irq());
+}
+
+power_attr_ro(pm_wakeup_irq);
+
+bool pm_debug_messages_on __read_mostly;
+
+bool pm_debug_messages_should_print(void)
+{
+	return pm_debug_messages_on && pm_suspend_target_state != PM_SUSPEND_ON;
+}
+EXPORT_SYMBOL_GPL(pm_debug_messages_should_print);
+
+static ssize_t pm_debug_messages_show(struct kobject *kobj,
+				      struct kobj_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", pm_debug_messages_on);
+}
+
+static ssize_t pm_debug_messages_store(struct kobject *kobj,
+				       struct kobj_attribute *attr,
+				       const char *buf, size_t n)
+{
+	unsigned long val;
+
+	if (kstrtoul(buf, 10, &val))
+		return -EINVAL;
+
+	if (val > 1)
+		return -EINVAL;
+
+	pm_debug_messages_on = !!val;
+	return n;
+}
+
+power_attr(pm_debug_messages);
+
+static int __init pm_debug_messages_setup(char *str)
+{
+	pm_debug_messages_on = true;
+	return 1;
+}
+__setup("pm_debug_messages", pm_debug_messages_setup);
+
+#else /* !CONFIG_PM_SLEEP_DEBUG */
+static inline void pm_print_times_init(void) {}
+#endif /* CONFIG_PM_SLEEP_DEBUG */
+
+struct kobject *power_kobj;
+
+/*
+ * state - control system sleep states.
+ *
+ * show() returns available sleep state labels, which may be "mem", "standby",
+ * "freeze" and "disk" (hibernation).
+ * See Documentation/admin-guide/pm/sleep-states.rst for a description of
+ * what they mean.
+ *
+ * store() accepts one of those strings, translates it into the proper
+ * enumerated value, and initiates a suspend transition.
+ */
+static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
+			  char *buf)
+{
+	char *s = buf;
+#ifdef CONFIG_SUSPEND
+	suspend_state_t i;
+
+	for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
+		if (pm_states[i])
+			s += sprintf(s,"%s ", pm_states[i]);
+
+#endif
+	if (hibernation_available())
+		s += sprintf(s, "disk ");
+	if (s != buf)
+		/* convert the last space to a newline */
+		*(s-1) = '\n';
+	return (s - buf);
+}
+
+static suspend_state_t decode_state(const char *buf, size_t n)
+{
+#ifdef CONFIG_SUSPEND
+	suspend_state_t state;
+#endif
+	char *p;
+	int len;
+
+	p = memchr(buf, '\n', n);
+	len = p ? p - buf : n;
+
+	/* Check hibernation first. */
+	if (len == 4 && str_has_prefix(buf, "disk"))
+		return PM_SUSPEND_MAX;
+
+#ifdef CONFIG_SUSPEND
+	for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
+		const char *label = pm_states[state];
+
+		if (label && len == strlen(label) && !strncmp(buf, label, len))
+			return state;
+	}
+#endif
+
+	return PM_SUSPEND_ON;
+}
+
+static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
+			   const char *buf, size_t n)
+{
+	suspend_state_t state;
+	int error;
+
+	error = pm_autosleep_lock();
+	if (error)
+		return error;
+
+	if (pm_autosleep_state() > PM_SUSPEND_ON) {
+		error = -EBUSY;
+		goto out;
+	}
+
+	state = decode_state(buf, n);
+	if (state < PM_SUSPEND_MAX) {
+		if (state == PM_SUSPEND_MEM)
+			state = mem_sleep_current;
+
+		error = pm_suspend(state);
+	} else if (state == PM_SUSPEND_MAX) {
+		error = hibernate();
+	} else {
+		error = -EINVAL;
+	}
+
+ out:
+	pm_autosleep_unlock();
+	return error ? error : n;
+}
+
+power_attr(state);
+
+#ifdef CONFIG_PM_SLEEP
+/*
+ * The 'wakeup_count' attribute, along with the functions defined in
+ * drivers/base/power/wakeup.c, provides a means by which wakeup events can be
+ * handled in a non-racy way.
+ *
+ * If a wakeup event occurs when the system is in a sleep state, it simply is
+ * woken up.  In turn, if an event that would wake the system up from a sleep
+ * state occurs when it is undergoing a transition to that sleep state, the
+ * transition should be aborted.  Moreover, if such an event occurs when the
+ * system is in the working state, an attempt to start a transition to the
+ * given sleep state should fail during certain period after the detection of
+ * the event.  Using the 'state' attribute alone is not sufficient to satisfy
+ * these requirements, because a wakeup event may occur exactly when 'state'
+ * is being written to and may be delivered to user space right before it is
+ * frozen, so the event will remain only partially processed until the system is
+ * woken up by another event.  In particular, it won't cause the transition to
+ * a sleep state to be aborted.
+ *
+ * This difficulty may be overcome if user space uses 'wakeup_count' before
+ * writing to 'state'.  It first should read from 'wakeup_count' and store
+ * the read value.  Then, after carrying out its own preparations for the system
+ * transition to a sleep state, it should write the stored value to
+ * 'wakeup_count'.  If that fails, at least one wakeup event has occurred since
+ * 'wakeup_count' was read and 'state' should not be written to.  Otherwise, it
+ * is allowed to write to 'state', but the transition will be aborted if there
+ * are any wakeup events detected after 'wakeup_count' was written to.
+ */
+
+static ssize_t wakeup_count_show(struct kobject *kobj,
+				struct kobj_attribute *attr,
+				char *buf)
+{
+	unsigned int val;
+
+	return pm_get_wakeup_count(&val, true) ?
+		sprintf(buf, "%u\n", val) : -EINTR;
+}
+
+static ssize_t wakeup_count_store(struct kobject *kobj,
+				struct kobj_attribute *attr,
+				const char *buf, size_t n)
+{
+	unsigned int val;
+	int error;
+
+	error = pm_autosleep_lock();
+	if (error)
+		return error;
+
+	if (pm_autosleep_state() > PM_SUSPEND_ON) {
+		error = -EBUSY;
+		goto out;
+	}
+
+	error = -EINVAL;
+	if (sscanf(buf, "%u", &val) == 1) {
+		if (pm_save_wakeup_count(val))
+			error = n;
+		else
+			pm_print_active_wakeup_sources();
+	}
+
+ out:
+	pm_autosleep_unlock();
+	return error;
+}
+
+power_attr(wakeup_count);
+
+#ifdef CONFIG_PM_AUTOSLEEP
+static ssize_t autosleep_show(struct kobject *kobj,
+			      struct kobj_attribute *attr,
+			      char *buf)
+{
+	suspend_state_t state = pm_autosleep_state();
+
+	if (state == PM_SUSPEND_ON)
+		return sprintf(buf, "off\n");
+
+#ifdef CONFIG_SUSPEND
+	if (state < PM_SUSPEND_MAX)
+		return sprintf(buf, "%s\n", pm_states[state] ?
+					pm_states[state] : "error");
+#endif
+#ifdef CONFIG_HIBERNATION
+	return sprintf(buf, "disk\n");
+#else
+	return sprintf(buf, "error");
+#endif
+}
+
+static ssize_t autosleep_store(struct kobject *kobj,
+			       struct kobj_attribute *attr,
+			       const char *buf, size_t n)
+{
+	suspend_state_t state = decode_state(buf, n);
+	int error;
+
+	if (state == PM_SUSPEND_ON
+	    && strcmp(buf, "off") && strcmp(buf, "off\n"))
+		return -EINVAL;
+
+	if (state == PM_SUSPEND_MEM)
+		state = mem_sleep_current;
+
+	error = pm_autosleep_set_state(state);
+	return error ? error : n;
+}
+
+power_attr(autosleep);
+#endif /* CONFIG_PM_AUTOSLEEP */
+
+#ifdef CONFIG_PM_WAKELOCKS
+static ssize_t wake_lock_show(struct kobject *kobj,
+			      struct kobj_attribute *attr,
+			      char *buf)
+{
+	return pm_show_wakelocks(buf, true);
+}
+
+static ssize_t wake_lock_store(struct kobject *kobj,
+			       struct kobj_attribute *attr,
+			       const char *buf, size_t n)
+{
+	int error = pm_wake_lock(buf);
+	return error ? error : n;
+}
+
+power_attr(wake_lock);
+
+static ssize_t wake_unlock_show(struct kobject *kobj,
+				struct kobj_attribute *attr,
+				char *buf)
+{
+	return pm_show_wakelocks(buf, false);
+}
+
+static ssize_t wake_unlock_store(struct kobject *kobj,
+				 struct kobj_attribute *attr,
+				 const char *buf, size_t n)
+{
+	int error = pm_wake_unlock(buf);
+	return error ? error : n;
+}
+
+power_attr(wake_unlock);
+
+#endif /* CONFIG_PM_WAKELOCKS */
+#endif /* CONFIG_PM_SLEEP */
+
+#ifdef CONFIG_PM_TRACE
+int pm_trace_enabled;
+
+static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
+			     char *buf)
+{
+	return sprintf(buf, "%d\n", pm_trace_enabled);
+}
+
+static ssize_t
+pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
+	       const char *buf, size_t n)
+{
+	int val;
+
+	if (sscanf(buf, "%d", &val) == 1) {
+		pm_trace_enabled = !!val;
+		if (pm_trace_enabled) {
+			pr_warn("PM: Enabling pm_trace changes system date and time during resume.\n"
+				"PM: Correct system time has to be restored manually after resume.\n");
+		}
+		return n;
+	}
+	return -EINVAL;
+}
+
+power_attr(pm_trace);
+
+static ssize_t pm_trace_dev_match_show(struct kobject *kobj,
+				       struct kobj_attribute *attr,
+				       char *buf)
+{
+	return show_trace_dev_match(buf, PAGE_SIZE);
+}
+
+power_attr_ro(pm_trace_dev_match);
+
+#endif /* CONFIG_PM_TRACE */
+
+#ifdef CONFIG_FREEZER
+static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
+				      struct kobj_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%u\n", freeze_timeout_msecs);
+}
+
+static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
+				       struct kobj_attribute *attr,
+				       const char *buf, size_t n)
+{
+	unsigned long val;
+
+	if (kstrtoul(buf, 10, &val))
+		return -EINVAL;
+
+	freeze_timeout_msecs = val;
+	return n;
+}
+
+power_attr(pm_freeze_timeout);
+
+#endif	/* CONFIG_FREEZER*/
+
+static struct attribute * g[] = {
+	&state_attr.attr,
+#ifdef CONFIG_PM_TRACE
+	&pm_trace_attr.attr,
+	&pm_trace_dev_match_attr.attr,
+#endif
+#ifdef CONFIG_PM_SLEEP
+	&pm_async_attr.attr,
+	&wakeup_count_attr.attr,
+#ifdef CONFIG_SUSPEND
+	&mem_sleep_attr.attr,
+	&sync_on_suspend_attr.attr,
+#endif
+#ifdef CONFIG_PM_AUTOSLEEP
+	&autosleep_attr.attr,
+#endif
+#ifdef CONFIG_PM_WAKELOCKS
+	&wake_lock_attr.attr,
+	&wake_unlock_attr.attr,
+#endif
+#ifdef CONFIG_PM_SLEEP_DEBUG
+	&pm_test_attr.attr,
+	&pm_print_times_attr.attr,
+	&pm_wakeup_irq_attr.attr,
+	&pm_debug_messages_attr.attr,
+#endif
+#endif
+#ifdef CONFIG_FREEZER
+	&pm_freeze_timeout_attr.attr,
+#endif
+	NULL,
+};
+
+static const struct attribute_group attr_group = {
+	.attrs = g,
+};
+
+static const struct attribute_group *attr_groups[] = {
+	&attr_group,
+#ifdef CONFIG_PM_SLEEP
+	&suspend_attr_group,
+#endif
+	NULL,
+};
+
+struct workqueue_struct *pm_wq;
+EXPORT_SYMBOL_GPL(pm_wq);
+
+static int __init pm_start_workqueue(void)
+{
+	pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
+
+	return pm_wq ? 0 : -ENOMEM;
+}
+
+static int __init pm_init(void)
+{
+	int error = pm_start_workqueue();
+	if (error)
+		return error;
+	hibernate_image_size_init();
+	hibernate_reserved_size_init();
+	pm_states_init();
+	power_kobj = kobject_create_and_add("power", NULL);
+	if (!power_kobj)
+		return -ENOMEM;
+	error = sysfs_create_groups(power_kobj, attr_groups);
+	if (error)
+		return error;
+	pm_print_times_init();
+	return pm_autosleep_init();
+}
+
+core_initcall(pm_init);
diff --git a/kernel/power/power.h b/kernel/power/power.h
new file mode 100644
index 000000000..a98f95e30
--- /dev/null
+++ b/kernel/power/power.h
@@ -0,0 +1,327 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/suspend.h>
+#include <linux/suspend_ioctls.h>
+#include <linux/utsname.h>
+#include <linux/freezer.h>
+#include <linux/compiler.h>
+#include <linux/cpu.h>
+#include <linux/cpuidle.h>
+
+struct swsusp_info {
+	struct new_utsname	uts;
+	u32			version_code;
+	unsigned long		num_physpages;
+	int			cpus;
+	unsigned long		image_pages;
+	unsigned long		pages;
+	unsigned long		size;
+} __aligned(PAGE_SIZE);
+
+#ifdef CONFIG_HIBERNATION
+/* kernel/power/snapshot.c */
+extern void __init hibernate_reserved_size_init(void);
+extern void __init hibernate_image_size_init(void);
+
+#ifdef CONFIG_ARCH_HIBERNATION_HEADER
+/* Maximum size of architecture specific data in a hibernation header */
+#define MAX_ARCH_HEADER_SIZE	(sizeof(struct new_utsname) + 4)
+
+static inline int init_header_complete(struct swsusp_info *info)
+{
+	return arch_hibernation_header_save(info, MAX_ARCH_HEADER_SIZE);
+}
+
+static inline const char *check_image_kernel(struct swsusp_info *info)
+{
+	return arch_hibernation_header_restore(info) ?
+			"architecture specific data" : NULL;
+}
+#endif /* CONFIG_ARCH_HIBERNATION_HEADER */
+
+/*
+ * Keep some memory free so that I/O operations can succeed without paging
+ * [Might this be more than 4 MB?]
+ */
+#define PAGES_FOR_IO	((4096 * 1024) >> PAGE_SHIFT)
+
+/*
+ * Keep 1 MB of memory free so that device drivers can allocate some pages in
+ * their .suspend() routines without breaking the suspend to disk.
+ */
+#define SPARE_PAGES	((1024 * 1024) >> PAGE_SHIFT)
+
+asmlinkage int swsusp_save(void);
+
+/* kernel/power/hibernate.c */
+extern bool freezer_test_done;
+
+extern int hibernation_snapshot(int platform_mode);
+extern int hibernation_restore(int platform_mode);
+extern int hibernation_platform_enter(void);
+
+#ifdef CONFIG_STRICT_KERNEL_RWX
+/* kernel/power/snapshot.c */
+extern void enable_restore_image_protection(void);
+#else
+static inline void enable_restore_image_protection(void) {}
+#endif /* CONFIG_STRICT_KERNEL_RWX */
+
+#else /* !CONFIG_HIBERNATION */
+
+static inline void hibernate_reserved_size_init(void) {}
+static inline void hibernate_image_size_init(void) {}
+#endif /* !CONFIG_HIBERNATION */
+
+#define power_attr(_name) \
+static struct kobj_attribute _name##_attr = {	\
+	.attr	= {				\
+		.name = __stringify(_name),	\
+		.mode = 0644,			\
+	},					\
+	.show	= _name##_show,			\
+	.store	= _name##_store,		\
+}
+
+#define power_attr_ro(_name) \
+static struct kobj_attribute _name##_attr = {	\
+	.attr	= {				\
+		.name = __stringify(_name),	\
+		.mode = S_IRUGO,		\
+	},					\
+	.show	= _name##_show,			\
+}
+
+/* Preferred image size in bytes (default 500 MB) */
+extern unsigned long image_size;
+/* Size of memory reserved for drivers (default SPARE_PAGES x PAGE_SIZE) */
+extern unsigned long reserved_size;
+extern int in_suspend;
+extern dev_t swsusp_resume_device;
+extern sector_t swsusp_resume_block;
+
+extern int create_basic_memory_bitmaps(void);
+extern void free_basic_memory_bitmaps(void);
+extern int hibernate_preallocate_memory(void);
+
+extern void clear_or_poison_free_pages(void);
+
+/**
+ *	Auxiliary structure used for reading the snapshot image data and
+ *	metadata from and writing them to the list of page backup entries
+ *	(PBEs) which is the main data structure of swsusp.
+ *
+ *	Using struct snapshot_handle we can transfer the image, including its
+ *	metadata, as a continuous sequence of bytes with the help of
+ *	snapshot_read_next() and snapshot_write_next().
+ *
+ *	The code that writes the image to a storage or transfers it to
+ *	the user land is required to use snapshot_read_next() for this
+ *	purpose and it should not make any assumptions regarding the internal
+ *	structure of the image.  Similarly, the code that reads the image from
+ *	a storage or transfers it from the user land is required to use
+ *	snapshot_write_next().
+ *
+ *	This may allow us to change the internal structure of the image
+ *	in the future with considerably less effort.
+ */
+
+struct snapshot_handle {
+	unsigned int	cur;	/* number of the block of PAGE_SIZE bytes the
+				 * next operation will refer to (ie. current)
+				 */
+	void		*buffer;	/* address of the block to read from
+					 * or write to
+					 */
+	int		sync_read;	/* Set to one to notify the caller of
+					 * snapshot_write_next() that it may
+					 * need to call wait_on_bio_chain()
+					 */
+};
+
+/* This macro returns the address from/to which the caller of
+ * snapshot_read_next()/snapshot_write_next() is allowed to
+ * read/write data after the function returns
+ */
+#define data_of(handle)	((handle).buffer)
+
+extern unsigned int snapshot_additional_pages(struct zone *zone);
+extern unsigned long snapshot_get_image_size(void);
+extern int snapshot_read_next(struct snapshot_handle *handle);
+extern int snapshot_write_next(struct snapshot_handle *handle);
+extern void snapshot_write_finalize(struct snapshot_handle *handle);
+extern int snapshot_image_loaded(struct snapshot_handle *handle);
+
+extern bool hibernate_acquire(void);
+extern void hibernate_release(void);
+
+extern sector_t alloc_swapdev_block(int swap);
+extern void free_all_swap_pages(int swap);
+extern int swsusp_swap_in_use(void);
+
+/*
+ * Flags that can be passed from the hibernatig hernel to the "boot" kernel in
+ * the image header.
+ */
+#define SF_PLATFORM_MODE	1
+#define SF_NOCOMPRESS_MODE	2
+#define SF_CRC32_MODE	        4
+#define SF_HW_SIG		8
+
+/* kernel/power/hibernate.c */
+int swsusp_check(bool exclusive);
+extern void swsusp_free(void);
+extern int swsusp_read(unsigned int *flags_p);
+extern int swsusp_write(unsigned int flags);
+void swsusp_close(bool exclusive);
+#ifdef CONFIG_SUSPEND
+extern int swsusp_unmark(void);
+#endif
+
+struct __kernel_old_timeval;
+/* kernel/power/swsusp.c */
+extern void swsusp_show_speed(ktime_t, ktime_t, unsigned int, char *);
+
+#ifdef CONFIG_SUSPEND
+/* kernel/power/suspend.c */
+extern const char * const pm_labels[];
+extern const char *pm_states[];
+extern const char *mem_sleep_states[];
+
+extern int suspend_devices_and_enter(suspend_state_t state);
+#else /* !CONFIG_SUSPEND */
+#define mem_sleep_current	PM_SUSPEND_ON
+
+static inline int suspend_devices_and_enter(suspend_state_t state)
+{
+	return -ENOSYS;
+}
+#endif /* !CONFIG_SUSPEND */
+
+#ifdef CONFIG_PM_TEST_SUSPEND
+/* kernel/power/suspend_test.c */
+extern void suspend_test_start(void);
+extern void suspend_test_finish(const char *label);
+#else /* !CONFIG_PM_TEST_SUSPEND */
+static inline void suspend_test_start(void) {}
+static inline void suspend_test_finish(const char *label) {}
+#endif /* !CONFIG_PM_TEST_SUSPEND */
+
+#ifdef CONFIG_PM_SLEEP
+/* kernel/power/main.c */
+extern int pm_notifier_call_chain_robust(unsigned long val_up, unsigned long val_down);
+extern int pm_notifier_call_chain(unsigned long val);
+void pm_restrict_gfp_mask(void);
+void pm_restore_gfp_mask(void);
+#else
+static inline void pm_restrict_gfp_mask(void) {}
+static inline void pm_restore_gfp_mask(void) {}
+#endif
+
+#ifdef CONFIG_HIGHMEM
+int restore_highmem(void);
+#else
+static inline unsigned int count_highmem_pages(void) { return 0; }
+static inline int restore_highmem(void) { return 0; }
+#endif
+
+/*
+ * Suspend test levels
+ */
+enum {
+	/* keep first */
+	TEST_NONE,
+	TEST_CORE,
+	TEST_CPUS,
+	TEST_PLATFORM,
+	TEST_DEVICES,
+	TEST_FREEZER,
+	/* keep last */
+	__TEST_AFTER_LAST
+};
+
+#define TEST_FIRST	TEST_NONE
+#define TEST_MAX	(__TEST_AFTER_LAST - 1)
+
+#ifdef CONFIG_PM_SLEEP_DEBUG
+extern int pm_test_level;
+#else
+#define pm_test_level	(TEST_NONE)
+#endif
+
+#ifdef CONFIG_SUSPEND_FREEZER
+static inline int suspend_freeze_processes(void)
+{
+	int error;
+
+	error = freeze_processes();
+	/*
+	 * freeze_processes() automatically thaws every task if freezing
+	 * fails. So we need not do anything extra upon error.
+	 */
+	if (error)
+		return error;
+
+	error = freeze_kernel_threads();
+	/*
+	 * freeze_kernel_threads() thaws only kernel threads upon freezing
+	 * failure. So we have to thaw the userspace tasks ourselves.
+	 */
+	if (error)
+		thaw_processes();
+
+	return error;
+}
+
+static inline void suspend_thaw_processes(void)
+{
+	thaw_processes();
+}
+#else
+static inline int suspend_freeze_processes(void)
+{
+	return 0;
+}
+
+static inline void suspend_thaw_processes(void)
+{
+}
+#endif
+
+#ifdef CONFIG_PM_AUTOSLEEP
+
+/* kernel/power/autosleep.c */
+extern int pm_autosleep_init(void);
+extern int pm_autosleep_lock(void);
+extern void pm_autosleep_unlock(void);
+extern suspend_state_t pm_autosleep_state(void);
+extern int pm_autosleep_set_state(suspend_state_t state);
+
+#else /* !CONFIG_PM_AUTOSLEEP */
+
+static inline int pm_autosleep_init(void) { return 0; }
+static inline int pm_autosleep_lock(void) { return 0; }
+static inline void pm_autosleep_unlock(void) {}
+static inline suspend_state_t pm_autosleep_state(void) { return PM_SUSPEND_ON; }
+
+#endif /* !CONFIG_PM_AUTOSLEEP */
+
+#ifdef CONFIG_PM_WAKELOCKS
+
+/* kernel/power/wakelock.c */
+extern ssize_t pm_show_wakelocks(char *buf, bool show_active);
+extern int pm_wake_lock(const char *buf);
+extern int pm_wake_unlock(const char *buf);
+
+#endif /* !CONFIG_PM_WAKELOCKS */
+
+static inline int pm_sleep_disable_secondary_cpus(void)
+{
+	cpuidle_pause();
+	return suspend_disable_secondary_cpus();
+}
+
+static inline void pm_sleep_enable_secondary_cpus(void)
+{
+	suspend_enable_secondary_cpus();
+	cpuidle_resume();
+}
diff --git a/kernel/power/poweroff.c b/kernel/power/poweroff.c
new file mode 100644
index 000000000..1f306f158
--- /dev/null
+++ b/kernel/power/poweroff.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * poweroff.c - sysrq handler to gracefully power down machine.
+ */
+
+#include <linux/kernel.h>
+#include <linux/sysrq.h>
+#include <linux/init.h>
+#include <linux/pm.h>
+#include <linux/workqueue.h>
+#include <linux/reboot.h>
+#include <linux/cpumask.h>
+
+/*
+ * When the user hits Sys-Rq o to power down the machine this is the
+ * callback we use.
+ */
+
+static void do_poweroff(struct work_struct *dummy)
+{
+	kernel_power_off();
+}
+
+static DECLARE_WORK(poweroff_work, do_poweroff);
+
+static void handle_poweroff(u8 key)
+{
+	/* run sysrq poweroff on boot cpu */
+	schedule_work_on(cpumask_first(cpu_online_mask), &poweroff_work);
+}
+
+static const struct sysrq_key_op	sysrq_poweroff_op = {
+	.handler        = handle_poweroff,
+	.help_msg       = "poweroff(o)",
+	.action_msg     = "Power Off",
+	.enable_mask	= SYSRQ_ENABLE_BOOT,
+};
+
+static int __init pm_sysrq_init(void)
+{
+	register_sysrq_key('o', &sysrq_poweroff_op);
+	return 0;
+}
+
+subsys_initcall(pm_sysrq_init);
diff --git a/kernel/power/process.c b/kernel/power/process.c
new file mode 100644
index 000000000..cae81a87c
--- /dev/null
+++ b/kernel/power/process.c
@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * drivers/power/process.c - Functions for starting/stopping processes on
+ *                           suspend transitions.
+ *
+ * Originally from swsusp.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/oom.h>
+#include <linux/suspend.h>
+#include <linux/module.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task.h>
+#include <linux/syscalls.h>
+#include <linux/freezer.h>
+#include <linux/delay.h>
+#include <linux/workqueue.h>
+#include <linux/kmod.h>
+#include <trace/events/power.h>
+#include <linux/cpuset.h>
+
+/*
+ * Timeout for stopping processes
+ */
+unsigned int __read_mostly freeze_timeout_msecs = 20 * MSEC_PER_SEC;
+
+static int try_to_freeze_tasks(bool user_only)
+{
+	const char *what = user_only ? "user space processes" :
+					"remaining freezable tasks";
+	struct task_struct *g, *p;
+	unsigned long end_time;
+	unsigned int todo;
+	bool wq_busy = false;
+	ktime_t start, end, elapsed;
+	unsigned int elapsed_msecs;
+	bool wakeup = false;
+	int sleep_usecs = USEC_PER_MSEC;
+
+	pr_info("Freezing %s\n", what);
+
+	start = ktime_get_boottime();
+
+	end_time = jiffies + msecs_to_jiffies(freeze_timeout_msecs);
+
+	if (!user_only)
+		freeze_workqueues_begin();
+
+	while (true) {
+		todo = 0;
+		read_lock(&tasklist_lock);
+		for_each_process_thread(g, p) {
+			if (p == current || !freeze_task(p))
+				continue;
+
+			todo++;
+		}
+		read_unlock(&tasklist_lock);
+
+		if (!user_only) {
+			wq_busy = freeze_workqueues_busy();
+			todo += wq_busy;
+		}
+
+		if (!todo || time_after(jiffies, end_time))
+			break;
+
+		if (pm_wakeup_pending()) {
+			wakeup = true;
+			break;
+		}
+
+		/*
+		 * We need to retry, but first give the freezing tasks some
+		 * time to enter the refrigerator.  Start with an initial
+		 * 1 ms sleep followed by exponential backoff until 8 ms.
+		 */
+		usleep_range(sleep_usecs / 2, sleep_usecs);
+		if (sleep_usecs < 8 * USEC_PER_MSEC)
+			sleep_usecs *= 2;
+	}
+
+	end = ktime_get_boottime();
+	elapsed = ktime_sub(end, start);
+	elapsed_msecs = ktime_to_ms(elapsed);
+
+	if (todo) {
+		pr_err("Freezing %s %s after %d.%03d seconds "
+		       "(%d tasks refusing to freeze, wq_busy=%d):\n", what,
+		       wakeup ? "aborted" : "failed",
+		       elapsed_msecs / 1000, elapsed_msecs % 1000,
+		       todo - wq_busy, wq_busy);
+
+		if (wq_busy)
+			show_freezable_workqueues();
+
+		if (!wakeup || pm_debug_messages_on) {
+			read_lock(&tasklist_lock);
+			for_each_process_thread(g, p) {
+				if (p != current && freezing(p) && !frozen(p))
+					sched_show_task(p);
+			}
+			read_unlock(&tasklist_lock);
+		}
+	} else {
+		pr_info("Freezing %s completed (elapsed %d.%03d seconds)\n",
+			what, elapsed_msecs / 1000, elapsed_msecs % 1000);
+	}
+
+	return todo ? -EBUSY : 0;
+}
+
+/**
+ * freeze_processes - Signal user space processes to enter the refrigerator.
+ * The current thread will not be frozen.  The same process that calls
+ * freeze_processes must later call thaw_processes.
+ *
+ * On success, returns 0.  On failure, -errno and system is fully thawed.
+ */
+int freeze_processes(void)
+{
+	int error;
+
+	error = __usermodehelper_disable(UMH_FREEZING);
+	if (error)
+		return error;
+
+	/* Make sure this task doesn't get frozen */
+	current->flags |= PF_SUSPEND_TASK;
+
+	if (!pm_freezing)
+		static_branch_inc(&freezer_active);
+
+	pm_wakeup_clear(0);
+	pm_freezing = true;
+	error = try_to_freeze_tasks(true);
+	if (!error)
+		__usermodehelper_set_disable_depth(UMH_DISABLED);
+
+	BUG_ON(in_atomic());
+
+	/*
+	 * Now that the whole userspace is frozen we need to disable
+	 * the OOM killer to disallow any further interference with
+	 * killable tasks. There is no guarantee oom victims will
+	 * ever reach a point they go away we have to wait with a timeout.
+	 */
+	if (!error && !oom_killer_disable(msecs_to_jiffies(freeze_timeout_msecs)))
+		error = -EBUSY;
+
+	if (error)
+		thaw_processes();
+	return error;
+}
+
+/**
+ * freeze_kernel_threads - Make freezable kernel threads go to the refrigerator.
+ *
+ * On success, returns 0.  On failure, -errno and only the kernel threads are
+ * thawed, so as to give a chance to the caller to do additional cleanups
+ * (if any) before thawing the userspace tasks. So, it is the responsibility
+ * of the caller to thaw the userspace tasks, when the time is right.
+ */
+int freeze_kernel_threads(void)
+{
+	int error;
+
+	pm_nosig_freezing = true;
+	error = try_to_freeze_tasks(false);
+
+	BUG_ON(in_atomic());
+
+	if (error)
+		thaw_kernel_threads();
+	return error;
+}
+
+void thaw_processes(void)
+{
+	struct task_struct *g, *p;
+	struct task_struct *curr = current;
+
+	trace_suspend_resume(TPS("thaw_processes"), 0, true);
+	if (pm_freezing)
+		static_branch_dec(&freezer_active);
+	pm_freezing = false;
+	pm_nosig_freezing = false;
+
+	oom_killer_enable();
+
+	pr_info("Restarting tasks ... ");
+
+	__usermodehelper_set_disable_depth(UMH_FREEZING);
+	thaw_workqueues();
+
+	cpuset_wait_for_hotplug();
+
+	read_lock(&tasklist_lock);
+	for_each_process_thread(g, p) {
+		/* No other threads should have PF_SUSPEND_TASK set */
+		WARN_ON((p != curr) && (p->flags & PF_SUSPEND_TASK));
+		__thaw_task(p);
+	}
+	read_unlock(&tasklist_lock);
+
+	WARN_ON(!(curr->flags & PF_SUSPEND_TASK));
+	curr->flags &= ~PF_SUSPEND_TASK;
+
+	usermodehelper_enable();
+
+	schedule();
+	pr_cont("done.\n");
+	trace_suspend_resume(TPS("thaw_processes"), 0, false);
+}
+
+void thaw_kernel_threads(void)
+{
+	struct task_struct *g, *p;
+
+	pm_nosig_freezing = false;
+	pr_info("Restarting kernel threads ... ");
+
+	thaw_workqueues();
+
+	read_lock(&tasklist_lock);
+	for_each_process_thread(g, p) {
+		if (p->flags & PF_KTHREAD)
+			__thaw_task(p);
+	}
+	read_unlock(&tasklist_lock);
+
+	schedule();
+	pr_cont("done.\n");
+}
diff --git a/kernel/power/qos.c b/kernel/power/qos.c
new file mode 100644
index 000000000..4244b0694
--- /dev/null
+++ b/kernel/power/qos.c
@@ -0,0 +1,683 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Power Management Quality of Service (PM QoS) support base.
+ *
+ * Copyright (C) 2020 Intel Corporation
+ *
+ * Authors:
+ *	Mark Gross <mgross@linux.intel.com>
+ *	Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ *
+ * Provided here is an interface for specifying PM QoS dependencies.  It allows
+ * entities depending on QoS constraints to register their requests which are
+ * aggregated as appropriate to produce effective constraints (target values)
+ * that can be monitored by entities needing to respect them, either by polling
+ * or through a built-in notification mechanism.
+ *
+ * In addition to the basic functionality, more specific interfaces for managing
+ * global CPU latency QoS requests and frequency QoS requests are provided.
+ */
+
+/*#define DEBUG*/
+
+#include <linux/pm_qos.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+#include <linux/string.h>
+#include <linux/platform_device.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#include <linux/uaccess.h>
+#include <linux/export.h>
+#include <trace/events/power.h>
+
+/*
+ * locking rule: all changes to constraints or notifiers lists
+ * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock
+ * held, taken with _irqsave.  One lock to rule them all
+ */
+static DEFINE_SPINLOCK(pm_qos_lock);
+
+/**
+ * pm_qos_read_value - Return the current effective constraint value.
+ * @c: List of PM QoS constraint requests.
+ */
+s32 pm_qos_read_value(struct pm_qos_constraints *c)
+{
+	return READ_ONCE(c->target_value);
+}
+
+static int pm_qos_get_value(struct pm_qos_constraints *c)
+{
+	if (plist_head_empty(&c->list))
+		return c->no_constraint_value;
+
+	switch (c->type) {
+	case PM_QOS_MIN:
+		return plist_first(&c->list)->prio;
+
+	case PM_QOS_MAX:
+		return plist_last(&c->list)->prio;
+
+	default:
+		WARN(1, "Unknown PM QoS type in %s\n", __func__);
+		return PM_QOS_DEFAULT_VALUE;
+	}
+}
+
+static void pm_qos_set_value(struct pm_qos_constraints *c, s32 value)
+{
+	WRITE_ONCE(c->target_value, value);
+}
+
+/**
+ * pm_qos_update_target - Update a list of PM QoS constraint requests.
+ * @c: List of PM QoS requests.
+ * @node: Target list entry.
+ * @action: Action to carry out (add, update or remove).
+ * @value: New request value for the target list entry.
+ *
+ * Update the given list of PM QoS constraint requests, @c, by carrying an
+ * @action involving the @node list entry and @value on it.
+ *
+ * The recognized values of @action are PM_QOS_ADD_REQ (store @value in @node
+ * and add it to the list), PM_QOS_UPDATE_REQ (remove @node from the list, store
+ * @value in it and add it to the list again), and PM_QOS_REMOVE_REQ (remove
+ * @node from the list, ignore @value).
+ *
+ * Return: 1 if the aggregate constraint value has changed, 0  otherwise.
+ */
+int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
+			 enum pm_qos_req_action action, int value)
+{
+	int prev_value, curr_value, new_value;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pm_qos_lock, flags);
+
+	prev_value = pm_qos_get_value(c);
+	if (value == PM_QOS_DEFAULT_VALUE)
+		new_value = c->default_value;
+	else
+		new_value = value;
+
+	switch (action) {
+	case PM_QOS_REMOVE_REQ:
+		plist_del(node, &c->list);
+		break;
+	case PM_QOS_UPDATE_REQ:
+		/*
+		 * To change the list, atomically remove, reinit with new value
+		 * and add, then see if the aggregate has changed.
+		 */
+		plist_del(node, &c->list);
+		fallthrough;
+	case PM_QOS_ADD_REQ:
+		plist_node_init(node, new_value);
+		plist_add(node, &c->list);
+		break;
+	default:
+		/* no action */
+		;
+	}
+
+	curr_value = pm_qos_get_value(c);
+	pm_qos_set_value(c, curr_value);
+
+	spin_unlock_irqrestore(&pm_qos_lock, flags);
+
+	trace_pm_qos_update_target(action, prev_value, curr_value);
+
+	if (prev_value == curr_value)
+		return 0;
+
+	if (c->notifiers)
+		blocking_notifier_call_chain(c->notifiers, curr_value, NULL);
+
+	return 1;
+}
+
+/**
+ * pm_qos_flags_remove_req - Remove device PM QoS flags request.
+ * @pqf: Device PM QoS flags set to remove the request from.
+ * @req: Request to remove from the set.
+ */
+static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf,
+				    struct pm_qos_flags_request *req)
+{
+	s32 val = 0;
+
+	list_del(&req->node);
+	list_for_each_entry(req, &pqf->list, node)
+		val |= req->flags;
+
+	pqf->effective_flags = val;
+}
+
+/**
+ * pm_qos_update_flags - Update a set of PM QoS flags.
+ * @pqf: Set of PM QoS flags to update.
+ * @req: Request to add to the set, to modify, or to remove from the set.
+ * @action: Action to take on the set.
+ * @val: Value of the request to add or modify.
+ *
+ * Return: 1 if the aggregate constraint value has changed, 0 otherwise.
+ */
+bool pm_qos_update_flags(struct pm_qos_flags *pqf,
+			 struct pm_qos_flags_request *req,
+			 enum pm_qos_req_action action, s32 val)
+{
+	unsigned long irqflags;
+	s32 prev_value, curr_value;
+
+	spin_lock_irqsave(&pm_qos_lock, irqflags);
+
+	prev_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;
+
+	switch (action) {
+	case PM_QOS_REMOVE_REQ:
+		pm_qos_flags_remove_req(pqf, req);
+		break;
+	case PM_QOS_UPDATE_REQ:
+		pm_qos_flags_remove_req(pqf, req);
+		fallthrough;
+	case PM_QOS_ADD_REQ:
+		req->flags = val;
+		INIT_LIST_HEAD(&req->node);
+		list_add_tail(&req->node, &pqf->list);
+		pqf->effective_flags |= val;
+		break;
+	default:
+		/* no action */
+		;
+	}
+
+	curr_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;
+
+	spin_unlock_irqrestore(&pm_qos_lock, irqflags);
+
+	trace_pm_qos_update_flags(action, prev_value, curr_value);
+
+	return prev_value != curr_value;
+}
+
+#ifdef CONFIG_CPU_IDLE
+/* Definitions related to the CPU latency QoS. */
+
+static struct pm_qos_constraints cpu_latency_constraints = {
+	.list = PLIST_HEAD_INIT(cpu_latency_constraints.list),
+	.target_value = PM_QOS_CPU_LATENCY_DEFAULT_VALUE,
+	.default_value = PM_QOS_CPU_LATENCY_DEFAULT_VALUE,
+	.no_constraint_value = PM_QOS_CPU_LATENCY_DEFAULT_VALUE,
+	.type = PM_QOS_MIN,
+};
+
+static inline bool cpu_latency_qos_value_invalid(s32 value)
+{
+	return value < 0 && value != PM_QOS_DEFAULT_VALUE;
+}
+
+/**
+ * cpu_latency_qos_limit - Return current system-wide CPU latency QoS limit.
+ */
+s32 cpu_latency_qos_limit(void)
+{
+	return pm_qos_read_value(&cpu_latency_constraints);
+}
+
+/**
+ * cpu_latency_qos_request_active - Check the given PM QoS request.
+ * @req: PM QoS request to check.
+ *
+ * Return: 'true' if @req has been added to the CPU latency QoS list, 'false'
+ * otherwise.
+ */
+bool cpu_latency_qos_request_active(struct pm_qos_request *req)
+{
+	return req->qos == &cpu_latency_constraints;
+}
+EXPORT_SYMBOL_GPL(cpu_latency_qos_request_active);
+
+static void cpu_latency_qos_apply(struct pm_qos_request *req,
+				  enum pm_qos_req_action action, s32 value)
+{
+	int ret = pm_qos_update_target(req->qos, &req->node, action, value);
+	if (ret > 0)
+		wake_up_all_idle_cpus();
+}
+
+/**
+ * cpu_latency_qos_add_request - Add new CPU latency QoS request.
+ * @req: Pointer to a preallocated handle.
+ * @value: Requested constraint value.
+ *
+ * Use @value to initialize the request handle pointed to by @req, insert it as
+ * a new entry to the CPU latency QoS list and recompute the effective QoS
+ * constraint for that list.
+ *
+ * Callers need to save the handle for later use in updates and removal of the
+ * QoS request represented by it.
+ */
+void cpu_latency_qos_add_request(struct pm_qos_request *req, s32 value)
+{
+	if (!req || cpu_latency_qos_value_invalid(value))
+		return;
+
+	if (cpu_latency_qos_request_active(req)) {
+		WARN(1, KERN_ERR "%s called for already added request\n", __func__);
+		return;
+	}
+
+	trace_pm_qos_add_request(value);
+
+	req->qos = &cpu_latency_constraints;
+	cpu_latency_qos_apply(req, PM_QOS_ADD_REQ, value);
+}
+EXPORT_SYMBOL_GPL(cpu_latency_qos_add_request);
+
+/**
+ * cpu_latency_qos_update_request - Modify existing CPU latency QoS request.
+ * @req : QoS request to update.
+ * @new_value: New requested constraint value.
+ *
+ * Use @new_value to update the QoS request represented by @req in the CPU
+ * latency QoS list along with updating the effective constraint value for that
+ * list.
+ */
+void cpu_latency_qos_update_request(struct pm_qos_request *req, s32 new_value)
+{
+	if (!req || cpu_latency_qos_value_invalid(new_value))
+		return;
+
+	if (!cpu_latency_qos_request_active(req)) {
+		WARN(1, KERN_ERR "%s called for unknown object\n", __func__);
+		return;
+	}
+
+	trace_pm_qos_update_request(new_value);
+
+	if (new_value == req->node.prio)
+		return;
+
+	cpu_latency_qos_apply(req, PM_QOS_UPDATE_REQ, new_value);
+}
+EXPORT_SYMBOL_GPL(cpu_latency_qos_update_request);
+
+/**
+ * cpu_latency_qos_remove_request - Remove existing CPU latency QoS request.
+ * @req: QoS request to remove.
+ *
+ * Remove the CPU latency QoS request represented by @req from the CPU latency
+ * QoS list along with updating the effective constraint value for that list.
+ */
+void cpu_latency_qos_remove_request(struct pm_qos_request *req)
+{
+	if (!req)
+		return;
+
+	if (!cpu_latency_qos_request_active(req)) {
+		WARN(1, KERN_ERR "%s called for unknown object\n", __func__);
+		return;
+	}
+
+	trace_pm_qos_remove_request(PM_QOS_DEFAULT_VALUE);
+
+	cpu_latency_qos_apply(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
+	memset(req, 0, sizeof(*req));
+}
+EXPORT_SYMBOL_GPL(cpu_latency_qos_remove_request);
+
+/* User space interface to the CPU latency QoS via misc device. */
+
+static int cpu_latency_qos_open(struct inode *inode, struct file *filp)
+{
+	struct pm_qos_request *req;
+
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
+
+	cpu_latency_qos_add_request(req, PM_QOS_DEFAULT_VALUE);
+	filp->private_data = req;
+
+	return 0;
+}
+
+static int cpu_latency_qos_release(struct inode *inode, struct file *filp)
+{
+	struct pm_qos_request *req = filp->private_data;
+
+	filp->private_data = NULL;
+
+	cpu_latency_qos_remove_request(req);
+	kfree(req);
+
+	return 0;
+}
+
+static ssize_t cpu_latency_qos_read(struct file *filp, char __user *buf,
+				    size_t count, loff_t *f_pos)
+{
+	struct pm_qos_request *req = filp->private_data;
+	unsigned long flags;
+	s32 value;
+
+	if (!req || !cpu_latency_qos_request_active(req))
+		return -EINVAL;
+
+	spin_lock_irqsave(&pm_qos_lock, flags);
+	value = pm_qos_get_value(&cpu_latency_constraints);
+	spin_unlock_irqrestore(&pm_qos_lock, flags);
+
+	return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32));
+}
+
+static ssize_t cpu_latency_qos_write(struct file *filp, const char __user *buf,
+				     size_t count, loff_t *f_pos)
+{
+	s32 value;
+
+	if (count == sizeof(s32)) {
+		if (copy_from_user(&value, buf, sizeof(s32)))
+			return -EFAULT;
+	} else {
+		int ret;
+
+		ret = kstrtos32_from_user(buf, count, 16, &value);
+		if (ret)
+			return ret;
+	}
+
+	cpu_latency_qos_update_request(filp->private_data, value);
+
+	return count;
+}
+
+static const struct file_operations cpu_latency_qos_fops = {
+	.write = cpu_latency_qos_write,
+	.read = cpu_latency_qos_read,
+	.open = cpu_latency_qos_open,
+	.release = cpu_latency_qos_release,
+	.llseek = noop_llseek,
+};
+
+static struct miscdevice cpu_latency_qos_miscdev = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "cpu_dma_latency",
+	.fops = &cpu_latency_qos_fops,
+};
+
+static int __init cpu_latency_qos_init(void)
+{
+	int ret;
+
+	ret = misc_register(&cpu_latency_qos_miscdev);
+	if (ret < 0)
+		pr_err("%s: %s setup failed\n", __func__,
+		       cpu_latency_qos_miscdev.name);
+
+	return ret;
+}
+late_initcall(cpu_latency_qos_init);
+#endif /* CONFIG_CPU_IDLE */
+
+/* Definitions related to the frequency QoS below. */
+
+static inline bool freq_qos_value_invalid(s32 value)
+{
+	return value < 0 && value != PM_QOS_DEFAULT_VALUE;
+}
+
+/**
+ * freq_constraints_init - Initialize frequency QoS constraints.
+ * @qos: Frequency QoS constraints to initialize.
+ */
+void freq_constraints_init(struct freq_constraints *qos)
+{
+	struct pm_qos_constraints *c;
+
+	c = &qos->min_freq;
+	plist_head_init(&c->list);
+	c->target_value = FREQ_QOS_MIN_DEFAULT_VALUE;
+	c->default_value = FREQ_QOS_MIN_DEFAULT_VALUE;
+	c->no_constraint_value = FREQ_QOS_MIN_DEFAULT_VALUE;
+	c->type = PM_QOS_MAX;
+	c->notifiers = &qos->min_freq_notifiers;
+	BLOCKING_INIT_NOTIFIER_HEAD(c->notifiers);
+
+	c = &qos->max_freq;
+	plist_head_init(&c->list);
+	c->target_value = FREQ_QOS_MAX_DEFAULT_VALUE;
+	c->default_value = FREQ_QOS_MAX_DEFAULT_VALUE;
+	c->no_constraint_value = FREQ_QOS_MAX_DEFAULT_VALUE;
+	c->type = PM_QOS_MIN;
+	c->notifiers = &qos->max_freq_notifiers;
+	BLOCKING_INIT_NOTIFIER_HEAD(c->notifiers);
+}
+
+/**
+ * freq_qos_read_value - Get frequency QoS constraint for a given list.
+ * @qos: Constraints to evaluate.
+ * @type: QoS request type.
+ */
+s32 freq_qos_read_value(struct freq_constraints *qos,
+			enum freq_qos_req_type type)
+{
+	s32 ret;
+
+	switch (type) {
+	case FREQ_QOS_MIN:
+		ret = IS_ERR_OR_NULL(qos) ?
+			FREQ_QOS_MIN_DEFAULT_VALUE :
+			pm_qos_read_value(&qos->min_freq);
+		break;
+	case FREQ_QOS_MAX:
+		ret = IS_ERR_OR_NULL(qos) ?
+			FREQ_QOS_MAX_DEFAULT_VALUE :
+			pm_qos_read_value(&qos->max_freq);
+		break;
+	default:
+		WARN_ON(1);
+		ret = 0;
+	}
+
+	return ret;
+}
+
+/**
+ * freq_qos_apply - Add/modify/remove frequency QoS request.
+ * @req: Constraint request to apply.
+ * @action: Action to perform (add/update/remove).
+ * @value: Value to assign to the QoS request.
+ *
+ * This is only meant to be called from inside pm_qos, not drivers.
+ */
+int freq_qos_apply(struct freq_qos_request *req,
+			  enum pm_qos_req_action action, s32 value)
+{
+	int ret;
+
+	switch(req->type) {
+	case FREQ_QOS_MIN:
+		ret = pm_qos_update_target(&req->qos->min_freq, &req->pnode,
+					   action, value);
+		break;
+	case FREQ_QOS_MAX:
+		ret = pm_qos_update_target(&req->qos->max_freq, &req->pnode,
+					   action, value);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+/**
+ * freq_qos_add_request - Insert new frequency QoS request into a given list.
+ * @qos: Constraints to update.
+ * @req: Preallocated request object.
+ * @type: Request type.
+ * @value: Request value.
+ *
+ * Insert a new entry into the @qos list of requests, recompute the effective
+ * QoS constraint value for that list and initialize the @req object.  The
+ * caller needs to save that object for later use in updates and removal.
+ *
+ * Return 1 if the effective constraint value has changed, 0 if the effective
+ * constraint value has not changed, or a negative error code on failures.
+ */
+int freq_qos_add_request(struct freq_constraints *qos,
+			 struct freq_qos_request *req,
+			 enum freq_qos_req_type type, s32 value)
+{
+	int ret;
+
+	if (IS_ERR_OR_NULL(qos) || !req || freq_qos_value_invalid(value))
+		return -EINVAL;
+
+	if (WARN(freq_qos_request_active(req),
+		 "%s() called for active request\n", __func__))
+		return -EINVAL;
+
+	req->qos = qos;
+	req->type = type;
+	ret = freq_qos_apply(req, PM_QOS_ADD_REQ, value);
+	if (ret < 0) {
+		req->qos = NULL;
+		req->type = 0;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(freq_qos_add_request);
+
+/**
+ * freq_qos_update_request - Modify existing frequency QoS request.
+ * @req: Request to modify.
+ * @new_value: New request value.
+ *
+ * Update an existing frequency QoS request along with the effective constraint
+ * value for the list of requests it belongs to.
+ *
+ * Return 1 if the effective constraint value has changed, 0 if the effective
+ * constraint value has not changed, or a negative error code on failures.
+ */
+int freq_qos_update_request(struct freq_qos_request *req, s32 new_value)
+{
+	if (!req || freq_qos_value_invalid(new_value))
+		return -EINVAL;
+
+	if (WARN(!freq_qos_request_active(req),
+		 "%s() called for unknown object\n", __func__))
+		return -EINVAL;
+
+	if (req->pnode.prio == new_value)
+		return 0;
+
+	return freq_qos_apply(req, PM_QOS_UPDATE_REQ, new_value);
+}
+EXPORT_SYMBOL_GPL(freq_qos_update_request);
+
+/**
+ * freq_qos_remove_request - Remove frequency QoS request from its list.
+ * @req: Request to remove.
+ *
+ * Remove the given frequency QoS request from the list of constraints it
+ * belongs to and recompute the effective constraint value for that list.
+ *
+ * Return 1 if the effective constraint value has changed, 0 if the effective
+ * constraint value has not changed, or a negative error code on failures.
+ */
+int freq_qos_remove_request(struct freq_qos_request *req)
+{
+	int ret;
+
+	if (!req)
+		return -EINVAL;
+
+	if (WARN(!freq_qos_request_active(req),
+		 "%s() called for unknown object\n", __func__))
+		return -EINVAL;
+
+	ret = freq_qos_apply(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
+	req->qos = NULL;
+	req->type = 0;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(freq_qos_remove_request);
+
+/**
+ * freq_qos_add_notifier - Add frequency QoS change notifier.
+ * @qos: List of requests to add the notifier to.
+ * @type: Request type.
+ * @notifier: Notifier block to add.
+ */
+int freq_qos_add_notifier(struct freq_constraints *qos,
+			  enum freq_qos_req_type type,
+			  struct notifier_block *notifier)
+{
+	int ret;
+
+	if (IS_ERR_OR_NULL(qos) || !notifier)
+		return -EINVAL;
+
+	switch (type) {
+	case FREQ_QOS_MIN:
+		ret = blocking_notifier_chain_register(qos->min_freq.notifiers,
+						       notifier);
+		break;
+	case FREQ_QOS_MAX:
+		ret = blocking_notifier_chain_register(qos->max_freq.notifiers,
+						       notifier);
+		break;
+	default:
+		WARN_ON(1);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(freq_qos_add_notifier);
+
+/**
+ * freq_qos_remove_notifier - Remove frequency QoS change notifier.
+ * @qos: List of requests to remove the notifier from.
+ * @type: Request type.
+ * @notifier: Notifier block to remove.
+ */
+int freq_qos_remove_notifier(struct freq_constraints *qos,
+			     enum freq_qos_req_type type,
+			     struct notifier_block *notifier)
+{
+	int ret;
+
+	if (IS_ERR_OR_NULL(qos) || !notifier)
+		return -EINVAL;
+
+	switch (type) {
+	case FREQ_QOS_MIN:
+		ret = blocking_notifier_chain_unregister(qos->min_freq.notifiers,
+							 notifier);
+		break;
+	case FREQ_QOS_MAX:
+		ret = blocking_notifier_chain_unregister(qos->max_freq.notifiers,
+							 notifier);
+		break;
+	default:
+		WARN_ON(1);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(freq_qos_remove_notifier);
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
new file mode 100644
index 000000000..50a15408c
--- /dev/null
+++ b/kernel/power/snapshot.c
@@ -0,0 +1,2923 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/kernel/power/snapshot.c
+ *
+ * This file provides system snapshot/restore functionality for swsusp.
+ *
+ * Copyright (C) 1998-2005 Pavel Machek <pavel@ucw.cz>
+ * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
+ */
+
+#define pr_fmt(fmt) "PM: hibernation: " fmt
+
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/suspend.h>
+#include <linux/delay.h>
+#include <linux/bitops.h>
+#include <linux/spinlock.h>
+#include <linux/kernel.h>
+#include <linux/pm.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/memblock.h>
+#include <linux/nmi.h>
+#include <linux/syscalls.h>
+#include <linux/console.h>
+#include <linux/highmem.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/compiler.h>
+#include <linux/ktime.h>
+#include <linux/set_memory.h>
+
+#include <linux/uaccess.h>
+#include <asm/mmu_context.h>
+#include <asm/tlbflush.h>
+#include <asm/io.h>
+
+#include "power.h"
+
+#if defined(CONFIG_STRICT_KERNEL_RWX) && defined(CONFIG_ARCH_HAS_SET_MEMORY)
+static bool hibernate_restore_protection;
+static bool hibernate_restore_protection_active;
+
+void enable_restore_image_protection(void)
+{
+	hibernate_restore_protection = true;
+}
+
+static inline void hibernate_restore_protection_begin(void)
+{
+	hibernate_restore_protection_active = hibernate_restore_protection;
+}
+
+static inline void hibernate_restore_protection_end(void)
+{
+	hibernate_restore_protection_active = false;
+}
+
+static inline void hibernate_restore_protect_page(void *page_address)
+{
+	if (hibernate_restore_protection_active)
+		set_memory_ro((unsigned long)page_address, 1);
+}
+
+static inline void hibernate_restore_unprotect_page(void *page_address)
+{
+	if (hibernate_restore_protection_active)
+		set_memory_rw((unsigned long)page_address, 1);
+}
+#else
+static inline void hibernate_restore_protection_begin(void) {}
+static inline void hibernate_restore_protection_end(void) {}
+static inline void hibernate_restore_protect_page(void *page_address) {}
+static inline void hibernate_restore_unprotect_page(void *page_address) {}
+#endif /* CONFIG_STRICT_KERNEL_RWX  && CONFIG_ARCH_HAS_SET_MEMORY */
+
+
+/*
+ * The calls to set_direct_map_*() should not fail because remapping a page
+ * here means that we only update protection bits in an existing PTE.
+ * It is still worth to have a warning here if something changes and this
+ * will no longer be the case.
+ */
+static inline void hibernate_map_page(struct page *page)
+{
+	if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) {
+		int ret = set_direct_map_default_noflush(page);
+
+		if (ret)
+			pr_warn_once("Failed to remap page\n");
+	} else {
+		debug_pagealloc_map_pages(page, 1);
+	}
+}
+
+static inline void hibernate_unmap_page(struct page *page)
+{
+	if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) {
+		unsigned long addr = (unsigned long)page_address(page);
+		int ret  = set_direct_map_invalid_noflush(page);
+
+		if (ret)
+			pr_warn_once("Failed to remap page\n");
+
+		flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
+	} else {
+		debug_pagealloc_unmap_pages(page, 1);
+	}
+}
+
+static int swsusp_page_is_free(struct page *);
+static void swsusp_set_page_forbidden(struct page *);
+static void swsusp_unset_page_forbidden(struct page *);
+
+/*
+ * Number of bytes to reserve for memory allocations made by device drivers
+ * from their ->freeze() and ->freeze_noirq() callbacks so that they don't
+ * cause image creation to fail (tunable via /sys/power/reserved_size).
+ */
+unsigned long reserved_size;
+
+void __init hibernate_reserved_size_init(void)
+{
+	reserved_size = SPARE_PAGES * PAGE_SIZE;
+}
+
+/*
+ * Preferred image size in bytes (tunable via /sys/power/image_size).
+ * When it is set to N, swsusp will do its best to ensure the image
+ * size will not exceed N bytes, but if that is impossible, it will
+ * try to create the smallest image possible.
+ */
+unsigned long image_size;
+
+void __init hibernate_image_size_init(void)
+{
+	image_size = ((totalram_pages() * 2) / 5) * PAGE_SIZE;
+}
+
+/*
+ * List of PBEs needed for restoring the pages that were allocated before
+ * the suspend and included in the suspend image, but have also been
+ * allocated by the "resume" kernel, so their contents cannot be written
+ * directly to their "original" page frames.
+ */
+struct pbe *restore_pblist;
+
+/* struct linked_page is used to build chains of pages */
+
+#define LINKED_PAGE_DATA_SIZE	(PAGE_SIZE - sizeof(void *))
+
+struct linked_page {
+	struct linked_page *next;
+	char data[LINKED_PAGE_DATA_SIZE];
+} __packed;
+
+/*
+ * List of "safe" pages (ie. pages that were not used by the image kernel
+ * before hibernation) that may be used as temporary storage for image kernel
+ * memory contents.
+ */
+static struct linked_page *safe_pages_list;
+
+/* Pointer to an auxiliary buffer (1 page) */
+static void *buffer;
+
+#define PG_ANY		0
+#define PG_SAFE		1
+#define PG_UNSAFE_CLEAR	1
+#define PG_UNSAFE_KEEP	0
+
+static unsigned int allocated_unsafe_pages;
+
+/**
+ * get_image_page - Allocate a page for a hibernation image.
+ * @gfp_mask: GFP mask for the allocation.
+ * @safe_needed: Get pages that were not used before hibernation (restore only)
+ *
+ * During image restoration, for storing the PBE list and the image data, we can
+ * only use memory pages that do not conflict with the pages used before
+ * hibernation.  The "unsafe" pages have PageNosaveFree set and we count them
+ * using allocated_unsafe_pages.
+ *
+ * Each allocated image page is marked as PageNosave and PageNosaveFree so that
+ * swsusp_free() can release it.
+ */
+static void *get_image_page(gfp_t gfp_mask, int safe_needed)
+{
+	void *res;
+
+	res = (void *)get_zeroed_page(gfp_mask);
+	if (safe_needed)
+		while (res && swsusp_page_is_free(virt_to_page(res))) {
+			/* The page is unsafe, mark it for swsusp_free() */
+			swsusp_set_page_forbidden(virt_to_page(res));
+			allocated_unsafe_pages++;
+			res = (void *)get_zeroed_page(gfp_mask);
+		}
+	if (res) {
+		swsusp_set_page_forbidden(virt_to_page(res));
+		swsusp_set_page_free(virt_to_page(res));
+	}
+	return res;
+}
+
+static void *__get_safe_page(gfp_t gfp_mask)
+{
+	if (safe_pages_list) {
+		void *ret = safe_pages_list;
+
+		safe_pages_list = safe_pages_list->next;
+		memset(ret, 0, PAGE_SIZE);
+		return ret;
+	}
+	return get_image_page(gfp_mask, PG_SAFE);
+}
+
+unsigned long get_safe_page(gfp_t gfp_mask)
+{
+	return (unsigned long)__get_safe_page(gfp_mask);
+}
+
+static struct page *alloc_image_page(gfp_t gfp_mask)
+{
+	struct page *page;
+
+	page = alloc_page(gfp_mask);
+	if (page) {
+		swsusp_set_page_forbidden(page);
+		swsusp_set_page_free(page);
+	}
+	return page;
+}
+
+static void recycle_safe_page(void *page_address)
+{
+	struct linked_page *lp = page_address;
+
+	lp->next = safe_pages_list;
+	safe_pages_list = lp;
+}
+
+/**
+ * free_image_page - Free a page allocated for hibernation image.
+ * @addr: Address of the page to free.
+ * @clear_nosave_free: If set, clear the PageNosaveFree bit for the page.
+ *
+ * The page to free should have been allocated by get_image_page() (page flags
+ * set by it are affected).
+ */
+static inline void free_image_page(void *addr, int clear_nosave_free)
+{
+	struct page *page;
+
+	BUG_ON(!virt_addr_valid(addr));
+
+	page = virt_to_page(addr);
+
+	swsusp_unset_page_forbidden(page);
+	if (clear_nosave_free)
+		swsusp_unset_page_free(page);
+
+	__free_page(page);
+}
+
+static inline void free_list_of_pages(struct linked_page *list,
+				      int clear_page_nosave)
+{
+	while (list) {
+		struct linked_page *lp = list->next;
+
+		free_image_page(list, clear_page_nosave);
+		list = lp;
+	}
+}
+
+/*
+ * struct chain_allocator is used for allocating small objects out of
+ * a linked list of pages called 'the chain'.
+ *
+ * The chain grows each time when there is no room for a new object in
+ * the current page.  The allocated objects cannot be freed individually.
+ * It is only possible to free them all at once, by freeing the entire
+ * chain.
+ *
+ * NOTE: The chain allocator may be inefficient if the allocated objects
+ * are not much smaller than PAGE_SIZE.
+ */
+struct chain_allocator {
+	struct linked_page *chain;	/* the chain */
+	unsigned int used_space;	/* total size of objects allocated out
+					   of the current page */
+	gfp_t gfp_mask;		/* mask for allocating pages */
+	int safe_needed;	/* if set, only "safe" pages are allocated */
+};
+
+static void chain_init(struct chain_allocator *ca, gfp_t gfp_mask,
+		       int safe_needed)
+{
+	ca->chain = NULL;
+	ca->used_space = LINKED_PAGE_DATA_SIZE;
+	ca->gfp_mask = gfp_mask;
+	ca->safe_needed = safe_needed;
+}
+
+static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
+{
+	void *ret;
+
+	if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
+		struct linked_page *lp;
+
+		lp = ca->safe_needed ? __get_safe_page(ca->gfp_mask) :
+					get_image_page(ca->gfp_mask, PG_ANY);
+		if (!lp)
+			return NULL;
+
+		lp->next = ca->chain;
+		ca->chain = lp;
+		ca->used_space = 0;
+	}
+	ret = ca->chain->data + ca->used_space;
+	ca->used_space += size;
+	return ret;
+}
+
+/*
+ * Data types related to memory bitmaps.
+ *
+ * Memory bitmap is a structure consisting of many linked lists of
+ * objects.  The main list's elements are of type struct zone_bitmap
+ * and each of them corresponds to one zone.  For each zone bitmap
+ * object there is a list of objects of type struct bm_block that
+ * represent each blocks of bitmap in which information is stored.
+ *
+ * struct memory_bitmap contains a pointer to the main list of zone
+ * bitmap objects, a struct bm_position used for browsing the bitmap,
+ * and a pointer to the list of pages used for allocating all of the
+ * zone bitmap objects and bitmap block objects.
+ *
+ * NOTE: It has to be possible to lay out the bitmap in memory
+ * using only allocations of order 0.  Additionally, the bitmap is
+ * designed to work with arbitrary number of zones (this is over the
+ * top for now, but let's avoid making unnecessary assumptions ;-).
+ *
+ * struct zone_bitmap contains a pointer to a list of bitmap block
+ * objects and a pointer to the bitmap block object that has been
+ * most recently used for setting bits.  Additionally, it contains the
+ * PFNs that correspond to the start and end of the represented zone.
+ *
+ * struct bm_block contains a pointer to the memory page in which
+ * information is stored (in the form of a block of bitmap)
+ * It also contains the pfns that correspond to the start and end of
+ * the represented memory area.
+ *
+ * The memory bitmap is organized as a radix tree to guarantee fast random
+ * access to the bits. There is one radix tree for each zone (as returned
+ * from create_mem_extents).
+ *
+ * One radix tree is represented by one struct mem_zone_bm_rtree. There are
+ * two linked lists for the nodes of the tree, one for the inner nodes and
+ * one for the leave nodes. The linked leave nodes are used for fast linear
+ * access of the memory bitmap.
+ *
+ * The struct rtree_node represents one node of the radix tree.
+ */
+
+#define BM_END_OF_MAP	(~0UL)
+
+#define BM_BITS_PER_BLOCK	(PAGE_SIZE * BITS_PER_BYTE)
+#define BM_BLOCK_SHIFT		(PAGE_SHIFT + 3)
+#define BM_BLOCK_MASK		((1UL << BM_BLOCK_SHIFT) - 1)
+
+/*
+ * struct rtree_node is a wrapper struct to link the nodes
+ * of the rtree together for easy linear iteration over
+ * bits and easy freeing
+ */
+struct rtree_node {
+	struct list_head list;
+	unsigned long *data;
+};
+
+/*
+ * struct mem_zone_bm_rtree represents a bitmap used for one
+ * populated memory zone.
+ */
+struct mem_zone_bm_rtree {
+	struct list_head list;		/* Link Zones together         */
+	struct list_head nodes;		/* Radix Tree inner nodes      */
+	struct list_head leaves;	/* Radix Tree leaves           */
+	unsigned long start_pfn;	/* Zone start page frame       */
+	unsigned long end_pfn;		/* Zone end page frame + 1     */
+	struct rtree_node *rtree;	/* Radix Tree Root             */
+	int levels;			/* Number of Radix Tree Levels */
+	unsigned int blocks;		/* Number of Bitmap Blocks     */
+};
+
+/* struct bm_position is used for browsing memory bitmaps */
+
+struct bm_position {
+	struct mem_zone_bm_rtree *zone;
+	struct rtree_node *node;
+	unsigned long node_pfn;
+	unsigned long cur_pfn;
+	int node_bit;
+};
+
+struct memory_bitmap {
+	struct list_head zones;
+	struct linked_page *p_list;	/* list of pages used to store zone
+					   bitmap objects and bitmap block
+					   objects */
+	struct bm_position cur;	/* most recently used bit position */
+};
+
+/* Functions that operate on memory bitmaps */
+
+#define BM_ENTRIES_PER_LEVEL	(PAGE_SIZE / sizeof(unsigned long))
+#if BITS_PER_LONG == 32
+#define BM_RTREE_LEVEL_SHIFT	(PAGE_SHIFT - 2)
+#else
+#define BM_RTREE_LEVEL_SHIFT	(PAGE_SHIFT - 3)
+#endif
+#define BM_RTREE_LEVEL_MASK	((1UL << BM_RTREE_LEVEL_SHIFT) - 1)
+
+/**
+ * alloc_rtree_node - Allocate a new node and add it to the radix tree.
+ * @gfp_mask: GFP mask for the allocation.
+ * @safe_needed: Get pages not used before hibernation (restore only)
+ * @ca: Pointer to a linked list of pages ("a chain") to allocate from
+ * @list: Radix Tree node to add.
+ *
+ * This function is used to allocate inner nodes as well as the
+ * leave nodes of the radix tree. It also adds the node to the
+ * corresponding linked list passed in by the *list parameter.
+ */
+static struct rtree_node *alloc_rtree_node(gfp_t gfp_mask, int safe_needed,
+					   struct chain_allocator *ca,
+					   struct list_head *list)
+{
+	struct rtree_node *node;
+
+	node = chain_alloc(ca, sizeof(struct rtree_node));
+	if (!node)
+		return NULL;
+
+	node->data = get_image_page(gfp_mask, safe_needed);
+	if (!node->data)
+		return NULL;
+
+	list_add_tail(&node->list, list);
+
+	return node;
+}
+
+/**
+ * add_rtree_block - Add a new leave node to the radix tree.
+ *
+ * The leave nodes need to be allocated in order to keep the leaves
+ * linked list in order. This is guaranteed by the zone->blocks
+ * counter.
+ */
+static int add_rtree_block(struct mem_zone_bm_rtree *zone, gfp_t gfp_mask,
+			   int safe_needed, struct chain_allocator *ca)
+{
+	struct rtree_node *node, *block, **dst;
+	unsigned int levels_needed, block_nr;
+	int i;
+
+	block_nr = zone->blocks;
+	levels_needed = 0;
+
+	/* How many levels do we need for this block nr? */
+	while (block_nr) {
+		levels_needed += 1;
+		block_nr >>= BM_RTREE_LEVEL_SHIFT;
+	}
+
+	/* Make sure the rtree has enough levels */
+	for (i = zone->levels; i < levels_needed; i++) {
+		node = alloc_rtree_node(gfp_mask, safe_needed, ca,
+					&zone->nodes);
+		if (!node)
+			return -ENOMEM;
+
+		node->data[0] = (unsigned long)zone->rtree;
+		zone->rtree = node;
+		zone->levels += 1;
+	}
+
+	/* Allocate new block */
+	block = alloc_rtree_node(gfp_mask, safe_needed, ca, &zone->leaves);
+	if (!block)
+		return -ENOMEM;
+
+	/* Now walk the rtree to insert the block */
+	node = zone->rtree;
+	dst = &zone->rtree;
+	block_nr = zone->blocks;
+	for (i = zone->levels; i > 0; i--) {
+		int index;
+
+		if (!node) {
+			node = alloc_rtree_node(gfp_mask, safe_needed, ca,
+						&zone->nodes);
+			if (!node)
+				return -ENOMEM;
+			*dst = node;
+		}
+
+		index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
+		index &= BM_RTREE_LEVEL_MASK;
+		dst = (struct rtree_node **)&((*dst)->data[index]);
+		node = *dst;
+	}
+
+	zone->blocks += 1;
+	*dst = block;
+
+	return 0;
+}
+
+static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
+			       int clear_nosave_free);
+
+/**
+ * create_zone_bm_rtree - Create a radix tree for one zone.
+ *
+ * Allocated the mem_zone_bm_rtree structure and initializes it.
+ * This function also allocated and builds the radix tree for the
+ * zone.
+ */
+static struct mem_zone_bm_rtree *create_zone_bm_rtree(gfp_t gfp_mask,
+						      int safe_needed,
+						      struct chain_allocator *ca,
+						      unsigned long start,
+						      unsigned long end)
+{
+	struct mem_zone_bm_rtree *zone;
+	unsigned int i, nr_blocks;
+	unsigned long pages;
+
+	pages = end - start;
+	zone  = chain_alloc(ca, sizeof(struct mem_zone_bm_rtree));
+	if (!zone)
+		return NULL;
+
+	INIT_LIST_HEAD(&zone->nodes);
+	INIT_LIST_HEAD(&zone->leaves);
+	zone->start_pfn = start;
+	zone->end_pfn = end;
+	nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK);
+
+	for (i = 0; i < nr_blocks; i++) {
+		if (add_rtree_block(zone, gfp_mask, safe_needed, ca)) {
+			free_zone_bm_rtree(zone, PG_UNSAFE_CLEAR);
+			return NULL;
+		}
+	}
+
+	return zone;
+}
+
+/**
+ * free_zone_bm_rtree - Free the memory of the radix tree.
+ *
+ * Free all node pages of the radix tree. The mem_zone_bm_rtree
+ * structure itself is not freed here nor are the rtree_node
+ * structs.
+ */
+static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
+			       int clear_nosave_free)
+{
+	struct rtree_node *node;
+
+	list_for_each_entry(node, &zone->nodes, list)
+		free_image_page(node->data, clear_nosave_free);
+
+	list_for_each_entry(node, &zone->leaves, list)
+		free_image_page(node->data, clear_nosave_free);
+}
+
+static void memory_bm_position_reset(struct memory_bitmap *bm)
+{
+	bm->cur.zone = list_entry(bm->zones.next, struct mem_zone_bm_rtree,
+				  list);
+	bm->cur.node = list_entry(bm->cur.zone->leaves.next,
+				  struct rtree_node, list);
+	bm->cur.node_pfn = 0;
+	bm->cur.cur_pfn = BM_END_OF_MAP;
+	bm->cur.node_bit = 0;
+}
+
+static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
+
+struct mem_extent {
+	struct list_head hook;
+	unsigned long start;
+	unsigned long end;
+};
+
+/**
+ * free_mem_extents - Free a list of memory extents.
+ * @list: List of extents to free.
+ */
+static void free_mem_extents(struct list_head *list)
+{
+	struct mem_extent *ext, *aux;
+
+	list_for_each_entry_safe(ext, aux, list, hook) {
+		list_del(&ext->hook);
+		kfree(ext);
+	}
+}
+
+/**
+ * create_mem_extents - Create a list of memory extents.
+ * @list: List to put the extents into.
+ * @gfp_mask: Mask to use for memory allocations.
+ *
+ * The extents represent contiguous ranges of PFNs.
+ */
+static int create_mem_extents(struct list_head *list, gfp_t gfp_mask)
+{
+	struct zone *zone;
+
+	INIT_LIST_HEAD(list);
+
+	for_each_populated_zone(zone) {
+		unsigned long zone_start, zone_end;
+		struct mem_extent *ext, *cur, *aux;
+
+		zone_start = zone->zone_start_pfn;
+		zone_end = zone_end_pfn(zone);
+
+		list_for_each_entry(ext, list, hook)
+			if (zone_start <= ext->end)
+				break;
+
+		if (&ext->hook == list || zone_end < ext->start) {
+			/* New extent is necessary */
+			struct mem_extent *new_ext;
+
+			new_ext = kzalloc(sizeof(struct mem_extent), gfp_mask);
+			if (!new_ext) {
+				free_mem_extents(list);
+				return -ENOMEM;
+			}
+			new_ext->start = zone_start;
+			new_ext->end = zone_end;
+			list_add_tail(&new_ext->hook, &ext->hook);
+			continue;
+		}
+
+		/* Merge this zone's range of PFNs with the existing one */
+		if (zone_start < ext->start)
+			ext->start = zone_start;
+		if (zone_end > ext->end)
+			ext->end = zone_end;
+
+		/* More merging may be possible */
+		cur = ext;
+		list_for_each_entry_safe_continue(cur, aux, list, hook) {
+			if (zone_end < cur->start)
+				break;
+			if (zone_end < cur->end)
+				ext->end = cur->end;
+			list_del(&cur->hook);
+			kfree(cur);
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * memory_bm_create - Allocate memory for a memory bitmap.
+ */
+static int memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask,
+			    int safe_needed)
+{
+	struct chain_allocator ca;
+	struct list_head mem_extents;
+	struct mem_extent *ext;
+	int error;
+
+	chain_init(&ca, gfp_mask, safe_needed);
+	INIT_LIST_HEAD(&bm->zones);
+
+	error = create_mem_extents(&mem_extents, gfp_mask);
+	if (error)
+		return error;
+
+	list_for_each_entry(ext, &mem_extents, hook) {
+		struct mem_zone_bm_rtree *zone;
+
+		zone = create_zone_bm_rtree(gfp_mask, safe_needed, &ca,
+					    ext->start, ext->end);
+		if (!zone) {
+			error = -ENOMEM;
+			goto Error;
+		}
+		list_add_tail(&zone->list, &bm->zones);
+	}
+
+	bm->p_list = ca.chain;
+	memory_bm_position_reset(bm);
+ Exit:
+	free_mem_extents(&mem_extents);
+	return error;
+
+ Error:
+	bm->p_list = ca.chain;
+	memory_bm_free(bm, PG_UNSAFE_CLEAR);
+	goto Exit;
+}
+
+/**
+ * memory_bm_free - Free memory occupied by the memory bitmap.
+ * @bm: Memory bitmap.
+ */
+static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
+{
+	struct mem_zone_bm_rtree *zone;
+
+	list_for_each_entry(zone, &bm->zones, list)
+		free_zone_bm_rtree(zone, clear_nosave_free);
+
+	free_list_of_pages(bm->p_list, clear_nosave_free);
+
+	INIT_LIST_HEAD(&bm->zones);
+}
+
+/**
+ * memory_bm_find_bit - Find the bit for a given PFN in a memory bitmap.
+ *
+ * Find the bit in memory bitmap @bm that corresponds to the given PFN.
+ * The cur.zone, cur.block and cur.node_pfn members of @bm are updated.
+ *
+ * Walk the radix tree to find the page containing the bit that represents @pfn
+ * and return the position of the bit in @addr and @bit_nr.
+ */
+static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
+			      void **addr, unsigned int *bit_nr)
+{
+	struct mem_zone_bm_rtree *curr, *zone;
+	struct rtree_node *node;
+	int i, block_nr;
+
+	zone = bm->cur.zone;
+
+	if (pfn >= zone->start_pfn && pfn < zone->end_pfn)
+		goto zone_found;
+
+	zone = NULL;
+
+	/* Find the right zone */
+	list_for_each_entry(curr, &bm->zones, list) {
+		if (pfn >= curr->start_pfn && pfn < curr->end_pfn) {
+			zone = curr;
+			break;
+		}
+	}
+
+	if (!zone)
+		return -EFAULT;
+
+zone_found:
+	/*
+	 * We have found the zone. Now walk the radix tree to find the leaf node
+	 * for our PFN.
+	 */
+
+	/*
+	 * If the zone we wish to scan is the current zone and the
+	 * pfn falls into the current node then we do not need to walk
+	 * the tree.
+	 */
+	node = bm->cur.node;
+	if (zone == bm->cur.zone &&
+	    ((pfn - zone->start_pfn) & ~BM_BLOCK_MASK) == bm->cur.node_pfn)
+		goto node_found;
+
+	node      = zone->rtree;
+	block_nr  = (pfn - zone->start_pfn) >> BM_BLOCK_SHIFT;
+
+	for (i = zone->levels; i > 0; i--) {
+		int index;
+
+		index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
+		index &= BM_RTREE_LEVEL_MASK;
+		BUG_ON(node->data[index] == 0);
+		node = (struct rtree_node *)node->data[index];
+	}
+
+node_found:
+	/* Update last position */
+	bm->cur.zone = zone;
+	bm->cur.node = node;
+	bm->cur.node_pfn = (pfn - zone->start_pfn) & ~BM_BLOCK_MASK;
+	bm->cur.cur_pfn = pfn;
+
+	/* Set return values */
+	*addr = node->data;
+	*bit_nr = (pfn - zone->start_pfn) & BM_BLOCK_MASK;
+
+	return 0;
+}
+
+static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
+{
+	void *addr;
+	unsigned int bit;
+	int error;
+
+	error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+	BUG_ON(error);
+	set_bit(bit, addr);
+}
+
+static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
+{
+	void *addr;
+	unsigned int bit;
+	int error;
+
+	error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+	if (!error)
+		set_bit(bit, addr);
+
+	return error;
+}
+
+static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
+{
+	void *addr;
+	unsigned int bit;
+	int error;
+
+	error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+	BUG_ON(error);
+	clear_bit(bit, addr);
+}
+
+static void memory_bm_clear_current(struct memory_bitmap *bm)
+{
+	int bit;
+
+	bit = max(bm->cur.node_bit - 1, 0);
+	clear_bit(bit, bm->cur.node->data);
+}
+
+static unsigned long memory_bm_get_current(struct memory_bitmap *bm)
+{
+	return bm->cur.cur_pfn;
+}
+
+static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
+{
+	void *addr;
+	unsigned int bit;
+	int error;
+
+	error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+	BUG_ON(error);
+	return test_bit(bit, addr);
+}
+
+static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn)
+{
+	void *addr;
+	unsigned int bit;
+
+	return !memory_bm_find_bit(bm, pfn, &addr, &bit);
+}
+
+/*
+ * rtree_next_node - Jump to the next leaf node.
+ *
+ * Set the position to the beginning of the next node in the
+ * memory bitmap. This is either the next node in the current
+ * zone's radix tree or the first node in the radix tree of the
+ * next zone.
+ *
+ * Return true if there is a next node, false otherwise.
+ */
+static bool rtree_next_node(struct memory_bitmap *bm)
+{
+	if (!list_is_last(&bm->cur.node->list, &bm->cur.zone->leaves)) {
+		bm->cur.node = list_entry(bm->cur.node->list.next,
+					  struct rtree_node, list);
+		bm->cur.node_pfn += BM_BITS_PER_BLOCK;
+		bm->cur.node_bit  = 0;
+		touch_softlockup_watchdog();
+		return true;
+	}
+
+	/* No more nodes, goto next zone */
+	if (!list_is_last(&bm->cur.zone->list, &bm->zones)) {
+		bm->cur.zone = list_entry(bm->cur.zone->list.next,
+				  struct mem_zone_bm_rtree, list);
+		bm->cur.node = list_entry(bm->cur.zone->leaves.next,
+					  struct rtree_node, list);
+		bm->cur.node_pfn = 0;
+		bm->cur.node_bit = 0;
+		return true;
+	}
+
+	/* No more zones */
+	return false;
+}
+
+/**
+ * memory_bm_next_pfn - Find the next set bit in a memory bitmap.
+ * @bm: Memory bitmap.
+ *
+ * Starting from the last returned position this function searches for the next
+ * set bit in @bm and returns the PFN represented by it.  If no more bits are
+ * set, BM_END_OF_MAP is returned.
+ *
+ * It is required to run memory_bm_position_reset() before the first call to
+ * this function for the given memory bitmap.
+ */
+static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
+{
+	unsigned long bits, pfn, pages;
+	int bit;
+
+	do {
+		pages	  = bm->cur.zone->end_pfn - bm->cur.zone->start_pfn;
+		bits      = min(pages - bm->cur.node_pfn, BM_BITS_PER_BLOCK);
+		bit	  = find_next_bit(bm->cur.node->data, bits,
+					  bm->cur.node_bit);
+		if (bit < bits) {
+			pfn = bm->cur.zone->start_pfn + bm->cur.node_pfn + bit;
+			bm->cur.node_bit = bit + 1;
+			bm->cur.cur_pfn = pfn;
+			return pfn;
+		}
+	} while (rtree_next_node(bm));
+
+	bm->cur.cur_pfn = BM_END_OF_MAP;
+	return BM_END_OF_MAP;
+}
+
+/*
+ * This structure represents a range of page frames the contents of which
+ * should not be saved during hibernation.
+ */
+struct nosave_region {
+	struct list_head list;
+	unsigned long start_pfn;
+	unsigned long end_pfn;
+};
+
+static LIST_HEAD(nosave_regions);
+
+static void recycle_zone_bm_rtree(struct mem_zone_bm_rtree *zone)
+{
+	struct rtree_node *node;
+
+	list_for_each_entry(node, &zone->nodes, list)
+		recycle_safe_page(node->data);
+
+	list_for_each_entry(node, &zone->leaves, list)
+		recycle_safe_page(node->data);
+}
+
+static void memory_bm_recycle(struct memory_bitmap *bm)
+{
+	struct mem_zone_bm_rtree *zone;
+	struct linked_page *p_list;
+
+	list_for_each_entry(zone, &bm->zones, list)
+		recycle_zone_bm_rtree(zone);
+
+	p_list = bm->p_list;
+	while (p_list) {
+		struct linked_page *lp = p_list;
+
+		p_list = lp->next;
+		recycle_safe_page(lp);
+	}
+}
+
+/**
+ * register_nosave_region - Register a region of unsaveable memory.
+ *
+ * Register a range of page frames the contents of which should not be saved
+ * during hibernation (to be used in the early initialization code).
+ */
+void __init register_nosave_region(unsigned long start_pfn, unsigned long end_pfn)
+{
+	struct nosave_region *region;
+
+	if (start_pfn >= end_pfn)
+		return;
+
+	if (!list_empty(&nosave_regions)) {
+		/* Try to extend the previous region (they should be sorted) */
+		region = list_entry(nosave_regions.prev,
+					struct nosave_region, list);
+		if (region->end_pfn == start_pfn) {
+			region->end_pfn = end_pfn;
+			goto Report;
+		}
+	}
+	/* This allocation cannot fail */
+	region = memblock_alloc(sizeof(struct nosave_region),
+				SMP_CACHE_BYTES);
+	if (!region)
+		panic("%s: Failed to allocate %zu bytes\n", __func__,
+		      sizeof(struct nosave_region));
+	region->start_pfn = start_pfn;
+	region->end_pfn = end_pfn;
+	list_add_tail(&region->list, &nosave_regions);
+ Report:
+	pr_info("Registered nosave memory: [mem %#010llx-%#010llx]\n",
+		(unsigned long long) start_pfn << PAGE_SHIFT,
+		((unsigned long long) end_pfn << PAGE_SHIFT) - 1);
+}
+
+/*
+ * Set bits in this map correspond to the page frames the contents of which
+ * should not be saved during the suspend.
+ */
+static struct memory_bitmap *forbidden_pages_map;
+
+/* Set bits in this map correspond to free page frames. */
+static struct memory_bitmap *free_pages_map;
+
+/*
+ * Each page frame allocated for creating the image is marked by setting the
+ * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
+ */
+
+void swsusp_set_page_free(struct page *page)
+{
+	if (free_pages_map)
+		memory_bm_set_bit(free_pages_map, page_to_pfn(page));
+}
+
+static int swsusp_page_is_free(struct page *page)
+{
+	return free_pages_map ?
+		memory_bm_test_bit(free_pages_map, page_to_pfn(page)) : 0;
+}
+
+void swsusp_unset_page_free(struct page *page)
+{
+	if (free_pages_map)
+		memory_bm_clear_bit(free_pages_map, page_to_pfn(page));
+}
+
+static void swsusp_set_page_forbidden(struct page *page)
+{
+	if (forbidden_pages_map)
+		memory_bm_set_bit(forbidden_pages_map, page_to_pfn(page));
+}
+
+int swsusp_page_is_forbidden(struct page *page)
+{
+	return forbidden_pages_map ?
+		memory_bm_test_bit(forbidden_pages_map, page_to_pfn(page)) : 0;
+}
+
+static void swsusp_unset_page_forbidden(struct page *page)
+{
+	if (forbidden_pages_map)
+		memory_bm_clear_bit(forbidden_pages_map, page_to_pfn(page));
+}
+
+/**
+ * mark_nosave_pages - Mark pages that should not be saved.
+ * @bm: Memory bitmap.
+ *
+ * Set the bits in @bm that correspond to the page frames the contents of which
+ * should not be saved.
+ */
+static void mark_nosave_pages(struct memory_bitmap *bm)
+{
+	struct nosave_region *region;
+
+	if (list_empty(&nosave_regions))
+		return;
+
+	list_for_each_entry(region, &nosave_regions, list) {
+		unsigned long pfn;
+
+		pr_debug("Marking nosave pages: [mem %#010llx-%#010llx]\n",
+			 (unsigned long long) region->start_pfn << PAGE_SHIFT,
+			 ((unsigned long long) region->end_pfn << PAGE_SHIFT)
+				- 1);
+
+		for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
+			if (pfn_valid(pfn)) {
+				/*
+				 * It is safe to ignore the result of
+				 * mem_bm_set_bit_check() here, since we won't
+				 * touch the PFNs for which the error is
+				 * returned anyway.
+				 */
+				mem_bm_set_bit_check(bm, pfn);
+			}
+	}
+}
+
+/**
+ * create_basic_memory_bitmaps - Create bitmaps to hold basic page information.
+ *
+ * Create bitmaps needed for marking page frames that should not be saved and
+ * free page frames.  The forbidden_pages_map and free_pages_map pointers are
+ * only modified if everything goes well, because we don't want the bits to be
+ * touched before both bitmaps are set up.
+ */
+int create_basic_memory_bitmaps(void)
+{
+	struct memory_bitmap *bm1, *bm2;
+	int error = 0;
+
+	if (forbidden_pages_map && free_pages_map)
+		return 0;
+	else
+		BUG_ON(forbidden_pages_map || free_pages_map);
+
+	bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
+	if (!bm1)
+		return -ENOMEM;
+
+	error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY);
+	if (error)
+		goto Free_first_object;
+
+	bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
+	if (!bm2)
+		goto Free_first_bitmap;
+
+	error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY);
+	if (error)
+		goto Free_second_object;
+
+	forbidden_pages_map = bm1;
+	free_pages_map = bm2;
+	mark_nosave_pages(forbidden_pages_map);
+
+	pr_debug("Basic memory bitmaps created\n");
+
+	return 0;
+
+ Free_second_object:
+	kfree(bm2);
+ Free_first_bitmap:
+	memory_bm_free(bm1, PG_UNSAFE_CLEAR);
+ Free_first_object:
+	kfree(bm1);
+	return -ENOMEM;
+}
+
+/**
+ * free_basic_memory_bitmaps - Free memory bitmaps holding basic information.
+ *
+ * Free memory bitmaps allocated by create_basic_memory_bitmaps().  The
+ * auxiliary pointers are necessary so that the bitmaps themselves are not
+ * referred to while they are being freed.
+ */
+void free_basic_memory_bitmaps(void)
+{
+	struct memory_bitmap *bm1, *bm2;
+
+	if (WARN_ON(!(forbidden_pages_map && free_pages_map)))
+		return;
+
+	bm1 = forbidden_pages_map;
+	bm2 = free_pages_map;
+	forbidden_pages_map = NULL;
+	free_pages_map = NULL;
+	memory_bm_free(bm1, PG_UNSAFE_CLEAR);
+	kfree(bm1);
+	memory_bm_free(bm2, PG_UNSAFE_CLEAR);
+	kfree(bm2);
+
+	pr_debug("Basic memory bitmaps freed\n");
+}
+
+static void clear_or_poison_free_page(struct page *page)
+{
+	if (page_poisoning_enabled_static())
+		__kernel_poison_pages(page, 1);
+	else if (want_init_on_free())
+		clear_highpage(page);
+}
+
+void clear_or_poison_free_pages(void)
+{
+	struct memory_bitmap *bm = free_pages_map;
+	unsigned long pfn;
+
+	if (WARN_ON(!(free_pages_map)))
+		return;
+
+	if (page_poisoning_enabled() || want_init_on_free()) {
+		memory_bm_position_reset(bm);
+		pfn = memory_bm_next_pfn(bm);
+		while (pfn != BM_END_OF_MAP) {
+			if (pfn_valid(pfn))
+				clear_or_poison_free_page(pfn_to_page(pfn));
+
+			pfn = memory_bm_next_pfn(bm);
+		}
+		memory_bm_position_reset(bm);
+		pr_info("free pages cleared after restore\n");
+	}
+}
+
+/**
+ * snapshot_additional_pages - Estimate the number of extra pages needed.
+ * @zone: Memory zone to carry out the computation for.
+ *
+ * Estimate the number of additional pages needed for setting up a hibernation
+ * image data structures for @zone (usually, the returned value is greater than
+ * the exact number).
+ */
+unsigned int snapshot_additional_pages(struct zone *zone)
+{
+	unsigned int rtree, nodes;
+
+	rtree = nodes = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
+	rtree += DIV_ROUND_UP(rtree * sizeof(struct rtree_node),
+			      LINKED_PAGE_DATA_SIZE);
+	while (nodes > 1) {
+		nodes = DIV_ROUND_UP(nodes, BM_ENTRIES_PER_LEVEL);
+		rtree += nodes;
+	}
+
+	return 2 * rtree;
+}
+
+/*
+ * Touch the watchdog for every WD_PAGE_COUNT pages.
+ */
+#define WD_PAGE_COUNT	(128*1024)
+
+static void mark_free_pages(struct zone *zone)
+{
+	unsigned long pfn, max_zone_pfn, page_count = WD_PAGE_COUNT;
+	unsigned long flags;
+	unsigned int order, t;
+	struct page *page;
+
+	if (zone_is_empty(zone))
+		return;
+
+	spin_lock_irqsave(&zone->lock, flags);
+
+	max_zone_pfn = zone_end_pfn(zone);
+	for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
+		if (pfn_valid(pfn)) {
+			page = pfn_to_page(pfn);
+
+			if (!--page_count) {
+				touch_nmi_watchdog();
+				page_count = WD_PAGE_COUNT;
+			}
+
+			if (page_zone(page) != zone)
+				continue;
+
+			if (!swsusp_page_is_forbidden(page))
+				swsusp_unset_page_free(page);
+		}
+
+	for_each_migratetype_order(order, t) {
+		list_for_each_entry(page,
+				&zone->free_area[order].free_list[t], buddy_list) {
+			unsigned long i;
+
+			pfn = page_to_pfn(page);
+			for (i = 0; i < (1UL << order); i++) {
+				if (!--page_count) {
+					touch_nmi_watchdog();
+					page_count = WD_PAGE_COUNT;
+				}
+				swsusp_set_page_free(pfn_to_page(pfn + i));
+			}
+		}
+	}
+	spin_unlock_irqrestore(&zone->lock, flags);
+}
+
+#ifdef CONFIG_HIGHMEM
+/**
+ * count_free_highmem_pages - Compute the total number of free highmem pages.
+ *
+ * The returned number is system-wide.
+ */
+static unsigned int count_free_highmem_pages(void)
+{
+	struct zone *zone;
+	unsigned int cnt = 0;
+
+	for_each_populated_zone(zone)
+		if (is_highmem(zone))
+			cnt += zone_page_state(zone, NR_FREE_PAGES);
+
+	return cnt;
+}
+
+/**
+ * saveable_highmem_page - Check if a highmem page is saveable.
+ *
+ * Determine whether a highmem page should be included in a hibernation image.
+ *
+ * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
+ * and it isn't part of a free chunk of pages.
+ */
+static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
+{
+	struct page *page;
+
+	if (!pfn_valid(pfn))
+		return NULL;
+
+	page = pfn_to_online_page(pfn);
+	if (!page || page_zone(page) != zone)
+		return NULL;
+
+	BUG_ON(!PageHighMem(page));
+
+	if (swsusp_page_is_forbidden(page) ||  swsusp_page_is_free(page))
+		return NULL;
+
+	if (PageReserved(page) || PageOffline(page))
+		return NULL;
+
+	if (page_is_guard(page))
+		return NULL;
+
+	return page;
+}
+
+/**
+ * count_highmem_pages - Compute the total number of saveable highmem pages.
+ */
+static unsigned int count_highmem_pages(void)
+{
+	struct zone *zone;
+	unsigned int n = 0;
+
+	for_each_populated_zone(zone) {
+		unsigned long pfn, max_zone_pfn;
+
+		if (!is_highmem(zone))
+			continue;
+
+		mark_free_pages(zone);
+		max_zone_pfn = zone_end_pfn(zone);
+		for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
+			if (saveable_highmem_page(zone, pfn))
+				n++;
+	}
+	return n;
+}
+#else
+static inline void *saveable_highmem_page(struct zone *z, unsigned long p)
+{
+	return NULL;
+}
+#endif /* CONFIG_HIGHMEM */
+
+/**
+ * saveable_page - Check if the given page is saveable.
+ *
+ * Determine whether a non-highmem page should be included in a hibernation
+ * image.
+ *
+ * We should save the page if it isn't Nosave, and is not in the range
+ * of pages statically defined as 'unsaveable', and it isn't part of
+ * a free chunk of pages.
+ */
+static struct page *saveable_page(struct zone *zone, unsigned long pfn)
+{
+	struct page *page;
+
+	if (!pfn_valid(pfn))
+		return NULL;
+
+	page = pfn_to_online_page(pfn);
+	if (!page || page_zone(page) != zone)
+		return NULL;
+
+	BUG_ON(PageHighMem(page));
+
+	if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
+		return NULL;
+
+	if (PageOffline(page))
+		return NULL;
+
+	if (PageReserved(page)
+	    && (!kernel_page_present(page) || pfn_is_nosave(pfn)))
+		return NULL;
+
+	if (page_is_guard(page))
+		return NULL;
+
+	return page;
+}
+
+/**
+ * count_data_pages - Compute the total number of saveable non-highmem pages.
+ */
+static unsigned int count_data_pages(void)
+{
+	struct zone *zone;
+	unsigned long pfn, max_zone_pfn;
+	unsigned int n = 0;
+
+	for_each_populated_zone(zone) {
+		if (is_highmem(zone))
+			continue;
+
+		mark_free_pages(zone);
+		max_zone_pfn = zone_end_pfn(zone);
+		for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
+			if (saveable_page(zone, pfn))
+				n++;
+	}
+	return n;
+}
+
+/*
+ * This is needed, because copy_page and memcpy are not usable for copying
+ * task structs. Returns true if the page was filled with only zeros,
+ * otherwise false.
+ */
+static inline bool do_copy_page(long *dst, long *src)
+{
+	long z = 0;
+	int n;
+
+	for (n = PAGE_SIZE / sizeof(long); n; n--) {
+		z |= *src;
+		*dst++ = *src++;
+	}
+	return !z;
+}
+
+/**
+ * safe_copy_page - Copy a page in a safe way.
+ *
+ * Check if the page we are going to copy is marked as present in the kernel
+ * page tables. This always is the case if CONFIG_DEBUG_PAGEALLOC or
+ * CONFIG_ARCH_HAS_SET_DIRECT_MAP is not set. In that case kernel_page_present()
+ * always returns 'true'. Returns true if the page was entirely composed of
+ * zeros, otherwise it will return false.
+ */
+static bool safe_copy_page(void *dst, struct page *s_page)
+{
+	bool zeros_only;
+
+	if (kernel_page_present(s_page)) {
+		zeros_only = do_copy_page(dst, page_address(s_page));
+	} else {
+		hibernate_map_page(s_page);
+		zeros_only = do_copy_page(dst, page_address(s_page));
+		hibernate_unmap_page(s_page);
+	}
+	return zeros_only;
+}
+
+#ifdef CONFIG_HIGHMEM
+static inline struct page *page_is_saveable(struct zone *zone, unsigned long pfn)
+{
+	return is_highmem(zone) ?
+		saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn);
+}
+
+static bool copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
+{
+	struct page *s_page, *d_page;
+	void *src, *dst;
+	bool zeros_only;
+
+	s_page = pfn_to_page(src_pfn);
+	d_page = pfn_to_page(dst_pfn);
+	if (PageHighMem(s_page)) {
+		src = kmap_atomic(s_page);
+		dst = kmap_atomic(d_page);
+		zeros_only = do_copy_page(dst, src);
+		kunmap_atomic(dst);
+		kunmap_atomic(src);
+	} else {
+		if (PageHighMem(d_page)) {
+			/*
+			 * The page pointed to by src may contain some kernel
+			 * data modified by kmap_atomic()
+			 */
+			zeros_only = safe_copy_page(buffer, s_page);
+			dst = kmap_atomic(d_page);
+			copy_page(dst, buffer);
+			kunmap_atomic(dst);
+		} else {
+			zeros_only = safe_copy_page(page_address(d_page), s_page);
+		}
+	}
+	return zeros_only;
+}
+#else
+#define page_is_saveable(zone, pfn)	saveable_page(zone, pfn)
+
+static inline int copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
+{
+	return safe_copy_page(page_address(pfn_to_page(dst_pfn)),
+				pfn_to_page(src_pfn));
+}
+#endif /* CONFIG_HIGHMEM */
+
+/*
+ * Copy data pages will copy all pages into pages pulled from the copy_bm.
+ * If a page was entirely filled with zeros it will be marked in the zero_bm.
+ *
+ * Returns the number of pages copied.
+ */
+static unsigned long copy_data_pages(struct memory_bitmap *copy_bm,
+			    struct memory_bitmap *orig_bm,
+			    struct memory_bitmap *zero_bm)
+{
+	unsigned long copied_pages = 0;
+	struct zone *zone;
+	unsigned long pfn, copy_pfn;
+
+	for_each_populated_zone(zone) {
+		unsigned long max_zone_pfn;
+
+		mark_free_pages(zone);
+		max_zone_pfn = zone_end_pfn(zone);
+		for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
+			if (page_is_saveable(zone, pfn))
+				memory_bm_set_bit(orig_bm, pfn);
+	}
+	memory_bm_position_reset(orig_bm);
+	memory_bm_position_reset(copy_bm);
+	copy_pfn = memory_bm_next_pfn(copy_bm);
+	for(;;) {
+		pfn = memory_bm_next_pfn(orig_bm);
+		if (unlikely(pfn == BM_END_OF_MAP))
+			break;
+		if (copy_data_page(copy_pfn, pfn)) {
+			memory_bm_set_bit(zero_bm, pfn);
+			/* Use this copy_pfn for a page that is not full of zeros */
+			continue;
+		}
+		copied_pages++;
+		copy_pfn = memory_bm_next_pfn(copy_bm);
+	}
+	return copied_pages;
+}
+
+/* Total number of image pages */
+static unsigned int nr_copy_pages;
+/* Number of pages needed for saving the original pfns of the image pages */
+static unsigned int nr_meta_pages;
+/* Number of zero pages */
+static unsigned int nr_zero_pages;
+
+/*
+ * Numbers of normal and highmem page frames allocated for hibernation image
+ * before suspending devices.
+ */
+static unsigned int alloc_normal, alloc_highmem;
+/*
+ * Memory bitmap used for marking saveable pages (during hibernation) or
+ * hibernation image pages (during restore)
+ */
+static struct memory_bitmap orig_bm;
+/*
+ * Memory bitmap used during hibernation for marking allocated page frames that
+ * will contain copies of saveable pages.  During restore it is initially used
+ * for marking hibernation image pages, but then the set bits from it are
+ * duplicated in @orig_bm and it is released.  On highmem systems it is next
+ * used for marking "safe" highmem pages, but it has to be reinitialized for
+ * this purpose.
+ */
+static struct memory_bitmap copy_bm;
+
+/* Memory bitmap which tracks which saveable pages were zero filled. */
+static struct memory_bitmap zero_bm;
+
+/**
+ * swsusp_free - Free pages allocated for hibernation image.
+ *
+ * Image pages are allocated before snapshot creation, so they need to be
+ * released after resume.
+ */
+void swsusp_free(void)
+{
+	unsigned long fb_pfn, fr_pfn;
+
+	if (!forbidden_pages_map || !free_pages_map)
+		goto out;
+
+	memory_bm_position_reset(forbidden_pages_map);
+	memory_bm_position_reset(free_pages_map);
+
+loop:
+	fr_pfn = memory_bm_next_pfn(free_pages_map);
+	fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
+
+	/*
+	 * Find the next bit set in both bitmaps. This is guaranteed to
+	 * terminate when fb_pfn == fr_pfn == BM_END_OF_MAP.
+	 */
+	do {
+		if (fb_pfn < fr_pfn)
+			fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
+		if (fr_pfn < fb_pfn)
+			fr_pfn = memory_bm_next_pfn(free_pages_map);
+	} while (fb_pfn != fr_pfn);
+
+	if (fr_pfn != BM_END_OF_MAP && pfn_valid(fr_pfn)) {
+		struct page *page = pfn_to_page(fr_pfn);
+
+		memory_bm_clear_current(forbidden_pages_map);
+		memory_bm_clear_current(free_pages_map);
+		hibernate_restore_unprotect_page(page_address(page));
+		__free_page(page);
+		goto loop;
+	}
+
+out:
+	nr_copy_pages = 0;
+	nr_meta_pages = 0;
+	nr_zero_pages = 0;
+	restore_pblist = NULL;
+	buffer = NULL;
+	alloc_normal = 0;
+	alloc_highmem = 0;
+	hibernate_restore_protection_end();
+}
+
+/* Helper functions used for the shrinking of memory. */
+
+#define GFP_IMAGE	(GFP_KERNEL | __GFP_NOWARN)
+
+/**
+ * preallocate_image_pages - Allocate a number of pages for hibernation image.
+ * @nr_pages: Number of page frames to allocate.
+ * @mask: GFP flags to use for the allocation.
+ *
+ * Return value: Number of page frames actually allocated
+ */
+static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask)
+{
+	unsigned long nr_alloc = 0;
+
+	while (nr_pages > 0) {
+		struct page *page;
+
+		page = alloc_image_page(mask);
+		if (!page)
+			break;
+		memory_bm_set_bit(&copy_bm, page_to_pfn(page));
+		if (PageHighMem(page))
+			alloc_highmem++;
+		else
+			alloc_normal++;
+		nr_pages--;
+		nr_alloc++;
+	}
+
+	return nr_alloc;
+}
+
+static unsigned long preallocate_image_memory(unsigned long nr_pages,
+					      unsigned long avail_normal)
+{
+	unsigned long alloc;
+
+	if (avail_normal <= alloc_normal)
+		return 0;
+
+	alloc = avail_normal - alloc_normal;
+	if (nr_pages < alloc)
+		alloc = nr_pages;
+
+	return preallocate_image_pages(alloc, GFP_IMAGE);
+}
+
+#ifdef CONFIG_HIGHMEM
+static unsigned long preallocate_image_highmem(unsigned long nr_pages)
+{
+	return preallocate_image_pages(nr_pages, GFP_IMAGE | __GFP_HIGHMEM);
+}
+
+/**
+ *  __fraction - Compute (an approximation of) x * (multiplier / base).
+ */
+static unsigned long __fraction(u64 x, u64 multiplier, u64 base)
+{
+	return div64_u64(x * multiplier, base);
+}
+
+static unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
+						  unsigned long highmem,
+						  unsigned long total)
+{
+	unsigned long alloc = __fraction(nr_pages, highmem, total);
+
+	return preallocate_image_pages(alloc, GFP_IMAGE | __GFP_HIGHMEM);
+}
+#else /* CONFIG_HIGHMEM */
+static inline unsigned long preallocate_image_highmem(unsigned long nr_pages)
+{
+	return 0;
+}
+
+static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
+							 unsigned long highmem,
+							 unsigned long total)
+{
+	return 0;
+}
+#endif /* CONFIG_HIGHMEM */
+
+/**
+ * free_unnecessary_pages - Release preallocated pages not needed for the image.
+ */
+static unsigned long free_unnecessary_pages(void)
+{
+	unsigned long save, to_free_normal, to_free_highmem, free;
+
+	save = count_data_pages();
+	if (alloc_normal >= save) {
+		to_free_normal = alloc_normal - save;
+		save = 0;
+	} else {
+		to_free_normal = 0;
+		save -= alloc_normal;
+	}
+	save += count_highmem_pages();
+	if (alloc_highmem >= save) {
+		to_free_highmem = alloc_highmem - save;
+	} else {
+		to_free_highmem = 0;
+		save -= alloc_highmem;
+		if (to_free_normal > save)
+			to_free_normal -= save;
+		else
+			to_free_normal = 0;
+	}
+	free = to_free_normal + to_free_highmem;
+
+	memory_bm_position_reset(&copy_bm);
+
+	while (to_free_normal > 0 || to_free_highmem > 0) {
+		unsigned long pfn = memory_bm_next_pfn(&copy_bm);
+		struct page *page = pfn_to_page(pfn);
+
+		if (PageHighMem(page)) {
+			if (!to_free_highmem)
+				continue;
+			to_free_highmem--;
+			alloc_highmem--;
+		} else {
+			if (!to_free_normal)
+				continue;
+			to_free_normal--;
+			alloc_normal--;
+		}
+		memory_bm_clear_bit(&copy_bm, pfn);
+		swsusp_unset_page_forbidden(page);
+		swsusp_unset_page_free(page);
+		__free_page(page);
+	}
+
+	return free;
+}
+
+/**
+ * minimum_image_size - Estimate the minimum acceptable size of an image.
+ * @saveable: Number of saveable pages in the system.
+ *
+ * We want to avoid attempting to free too much memory too hard, so estimate the
+ * minimum acceptable size of a hibernation image to use as the lower limit for
+ * preallocating memory.
+ *
+ * We assume that the minimum image size should be proportional to
+ *
+ * [number of saveable pages] - [number of pages that can be freed in theory]
+ *
+ * where the second term is the sum of (1) reclaimable slab pages, (2) active
+ * and (3) inactive anonymous pages, (4) active and (5) inactive file pages.
+ */
+static unsigned long minimum_image_size(unsigned long saveable)
+{
+	unsigned long size;
+
+	size = global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B)
+		+ global_node_page_state(NR_ACTIVE_ANON)
+		+ global_node_page_state(NR_INACTIVE_ANON)
+		+ global_node_page_state(NR_ACTIVE_FILE)
+		+ global_node_page_state(NR_INACTIVE_FILE);
+
+	return saveable <= size ? 0 : saveable - size;
+}
+
+/**
+ * hibernate_preallocate_memory - Preallocate memory for hibernation image.
+ *
+ * To create a hibernation image it is necessary to make a copy of every page
+ * frame in use.  We also need a number of page frames to be free during
+ * hibernation for allocations made while saving the image and for device
+ * drivers, in case they need to allocate memory from their hibernation
+ * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough
+ * estimate) and reserved_size divided by PAGE_SIZE (which is tunable through
+ * /sys/power/reserved_size, respectively).  To make this happen, we compute the
+ * total number of available page frames and allocate at least
+ *
+ * ([page frames total] - PAGES_FOR_IO - [metadata pages]) / 2
+ *  - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE)
+ *
+ * of them, which corresponds to the maximum size of a hibernation image.
+ *
+ * If image_size is set below the number following from the above formula,
+ * the preallocation of memory is continued until the total number of saveable
+ * pages in the system is below the requested image size or the minimum
+ * acceptable image size returned by minimum_image_size(), whichever is greater.
+ */
+int hibernate_preallocate_memory(void)
+{
+	struct zone *zone;
+	unsigned long saveable, size, max_size, count, highmem, pages = 0;
+	unsigned long alloc, save_highmem, pages_highmem, avail_normal;
+	ktime_t start, stop;
+	int error;
+
+	pr_info("Preallocating image memory\n");
+	start = ktime_get();
+
+	error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY);
+	if (error) {
+		pr_err("Cannot allocate original bitmap\n");
+		goto err_out;
+	}
+
+	error = memory_bm_create(&copy_bm, GFP_IMAGE, PG_ANY);
+	if (error) {
+		pr_err("Cannot allocate copy bitmap\n");
+		goto err_out;
+	}
+
+	error = memory_bm_create(&zero_bm, GFP_IMAGE, PG_ANY);
+	if (error) {
+		pr_err("Cannot allocate zero bitmap\n");
+		goto err_out;
+	}
+
+	alloc_normal = 0;
+	alloc_highmem = 0;
+	nr_zero_pages = 0;
+
+	/* Count the number of saveable data pages. */
+	save_highmem = count_highmem_pages();
+	saveable = count_data_pages();
+
+	/*
+	 * Compute the total number of page frames we can use (count) and the
+	 * number of pages needed for image metadata (size).
+	 */
+	count = saveable;
+	saveable += save_highmem;
+	highmem = save_highmem;
+	size = 0;
+	for_each_populated_zone(zone) {
+		size += snapshot_additional_pages(zone);
+		if (is_highmem(zone))
+			highmem += zone_page_state(zone, NR_FREE_PAGES);
+		else
+			count += zone_page_state(zone, NR_FREE_PAGES);
+	}
+	avail_normal = count;
+	count += highmem;
+	count -= totalreserve_pages;
+
+	/* Compute the maximum number of saveable pages to leave in memory. */
+	max_size = (count - (size + PAGES_FOR_IO)) / 2
+			- 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);
+	/* Compute the desired number of image pages specified by image_size. */
+	size = DIV_ROUND_UP(image_size, PAGE_SIZE);
+	if (size > max_size)
+		size = max_size;
+	/*
+	 * If the desired number of image pages is at least as large as the
+	 * current number of saveable pages in memory, allocate page frames for
+	 * the image and we're done.
+	 */
+	if (size >= saveable) {
+		pages = preallocate_image_highmem(save_highmem);
+		pages += preallocate_image_memory(saveable - pages, avail_normal);
+		goto out;
+	}
+
+	/* Estimate the minimum size of the image. */
+	pages = minimum_image_size(saveable);
+	/*
+	 * To avoid excessive pressure on the normal zone, leave room in it to
+	 * accommodate an image of the minimum size (unless it's already too
+	 * small, in which case don't preallocate pages from it at all).
+	 */
+	if (avail_normal > pages)
+		avail_normal -= pages;
+	else
+		avail_normal = 0;
+	if (size < pages)
+		size = min_t(unsigned long, pages, max_size);
+
+	/*
+	 * Let the memory management subsystem know that we're going to need a
+	 * large number of page frames to allocate and make it free some memory.
+	 * NOTE: If this is not done, performance will be hurt badly in some
+	 * test cases.
+	 */
+	shrink_all_memory(saveable - size);
+
+	/*
+	 * The number of saveable pages in memory was too high, so apply some
+	 * pressure to decrease it.  First, make room for the largest possible
+	 * image and fail if that doesn't work.  Next, try to decrease the size
+	 * of the image as much as indicated by 'size' using allocations from
+	 * highmem and non-highmem zones separately.
+	 */
+	pages_highmem = preallocate_image_highmem(highmem / 2);
+	alloc = count - max_size;
+	if (alloc > pages_highmem)
+		alloc -= pages_highmem;
+	else
+		alloc = 0;
+	pages = preallocate_image_memory(alloc, avail_normal);
+	if (pages < alloc) {
+		/* We have exhausted non-highmem pages, try highmem. */
+		alloc -= pages;
+		pages += pages_highmem;
+		pages_highmem = preallocate_image_highmem(alloc);
+		if (pages_highmem < alloc) {
+			pr_err("Image allocation is %lu pages short\n",
+				alloc - pages_highmem);
+			goto err_out;
+		}
+		pages += pages_highmem;
+		/*
+		 * size is the desired number of saveable pages to leave in
+		 * memory, so try to preallocate (all memory - size) pages.
+		 */
+		alloc = (count - pages) - size;
+		pages += preallocate_image_highmem(alloc);
+	} else {
+		/*
+		 * There are approximately max_size saveable pages at this point
+		 * and we want to reduce this number down to size.
+		 */
+		alloc = max_size - size;
+		size = preallocate_highmem_fraction(alloc, highmem, count);
+		pages_highmem += size;
+		alloc -= size;
+		size = preallocate_image_memory(alloc, avail_normal);
+		pages_highmem += preallocate_image_highmem(alloc - size);
+		pages += pages_highmem + size;
+	}
+
+	/*
+	 * We only need as many page frames for the image as there are saveable
+	 * pages in memory, but we have allocated more.  Release the excessive
+	 * ones now.
+	 */
+	pages -= free_unnecessary_pages();
+
+ out:
+	stop = ktime_get();
+	pr_info("Allocated %lu pages for snapshot\n", pages);
+	swsusp_show_speed(start, stop, pages, "Allocated");
+
+	return 0;
+
+ err_out:
+	swsusp_free();
+	return -ENOMEM;
+}
+
+#ifdef CONFIG_HIGHMEM
+/**
+ * count_pages_for_highmem - Count non-highmem pages needed for copying highmem.
+ *
+ * Compute the number of non-highmem pages that will be necessary for creating
+ * copies of highmem pages.
+ */
+static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
+{
+	unsigned int free_highmem = count_free_highmem_pages() + alloc_highmem;
+
+	if (free_highmem >= nr_highmem)
+		nr_highmem = 0;
+	else
+		nr_highmem -= free_highmem;
+
+	return nr_highmem;
+}
+#else
+static unsigned int count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
+#endif /* CONFIG_HIGHMEM */
+
+/**
+ * enough_free_mem - Check if there is enough free memory for the image.
+ */
+static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
+{
+	struct zone *zone;
+	unsigned int free = alloc_normal;
+
+	for_each_populated_zone(zone)
+		if (!is_highmem(zone))
+			free += zone_page_state(zone, NR_FREE_PAGES);
+
+	nr_pages += count_pages_for_highmem(nr_highmem);
+	pr_debug("Normal pages needed: %u + %u, available pages: %u\n",
+		 nr_pages, PAGES_FOR_IO, free);
+
+	return free > nr_pages + PAGES_FOR_IO;
+}
+
+#ifdef CONFIG_HIGHMEM
+/**
+ * get_highmem_buffer - Allocate a buffer for highmem pages.
+ *
+ * If there are some highmem pages in the hibernation image, we may need a
+ * buffer to copy them and/or load their data.
+ */
+static inline int get_highmem_buffer(int safe_needed)
+{
+	buffer = get_image_page(GFP_ATOMIC, safe_needed);
+	return buffer ? 0 : -ENOMEM;
+}
+
+/**
+ * alloc_highmem_pages - Allocate some highmem pages for the image.
+ *
+ * Try to allocate as many pages as needed, but if the number of free highmem
+ * pages is less than that, allocate them all.
+ */
+static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
+					       unsigned int nr_highmem)
+{
+	unsigned int to_alloc = count_free_highmem_pages();
+
+	if (to_alloc > nr_highmem)
+		to_alloc = nr_highmem;
+
+	nr_highmem -= to_alloc;
+	while (to_alloc-- > 0) {
+		struct page *page;
+
+		page = alloc_image_page(__GFP_HIGHMEM|__GFP_KSWAPD_RECLAIM);
+		memory_bm_set_bit(bm, page_to_pfn(page));
+	}
+	return nr_highmem;
+}
+#else
+static inline int get_highmem_buffer(int safe_needed) { return 0; }
+
+static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
+					       unsigned int n) { return 0; }
+#endif /* CONFIG_HIGHMEM */
+
+/**
+ * swsusp_alloc - Allocate memory for hibernation image.
+ *
+ * We first try to allocate as many highmem pages as there are
+ * saveable highmem pages in the system.  If that fails, we allocate
+ * non-highmem pages for the copies of the remaining highmem ones.
+ *
+ * In this approach it is likely that the copies of highmem pages will
+ * also be located in the high memory, because of the way in which
+ * copy_data_pages() works.
+ */
+static int swsusp_alloc(struct memory_bitmap *copy_bm,
+			unsigned int nr_pages, unsigned int nr_highmem)
+{
+	if (nr_highmem > 0) {
+		if (get_highmem_buffer(PG_ANY))
+			goto err_out;
+		if (nr_highmem > alloc_highmem) {
+			nr_highmem -= alloc_highmem;
+			nr_pages += alloc_highmem_pages(copy_bm, nr_highmem);
+		}
+	}
+	if (nr_pages > alloc_normal) {
+		nr_pages -= alloc_normal;
+		while (nr_pages-- > 0) {
+			struct page *page;
+
+			page = alloc_image_page(GFP_ATOMIC);
+			if (!page)
+				goto err_out;
+			memory_bm_set_bit(copy_bm, page_to_pfn(page));
+		}
+	}
+
+	return 0;
+
+ err_out:
+	swsusp_free();
+	return -ENOMEM;
+}
+
+asmlinkage __visible int swsusp_save(void)
+{
+	unsigned int nr_pages, nr_highmem;
+
+	pr_info("Creating image:\n");
+
+	drain_local_pages(NULL);
+	nr_pages = count_data_pages();
+	nr_highmem = count_highmem_pages();
+	pr_info("Need to copy %u pages\n", nr_pages + nr_highmem);
+
+	if (!enough_free_mem(nr_pages, nr_highmem)) {
+		pr_err("Not enough free memory\n");
+		return -ENOMEM;
+	}
+
+	if (swsusp_alloc(&copy_bm, nr_pages, nr_highmem)) {
+		pr_err("Memory allocation failed\n");
+		return -ENOMEM;
+	}
+
+	/*
+	 * During allocating of suspend pagedir, new cold pages may appear.
+	 * Kill them.
+	 */
+	drain_local_pages(NULL);
+	nr_copy_pages = copy_data_pages(&copy_bm, &orig_bm, &zero_bm);
+
+	/*
+	 * End of critical section. From now on, we can write to memory,
+	 * but we should not touch disk. This specially means we must _not_
+	 * touch swap space! Except we must write out our image of course.
+	 */
+	nr_pages += nr_highmem;
+	/* We don't actually copy the zero pages */
+	nr_zero_pages = nr_pages - nr_copy_pages;
+	nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
+
+	pr_info("Image created (%d pages copied, %d zero pages)\n", nr_copy_pages, nr_zero_pages);
+
+	return 0;
+}
+
+#ifndef CONFIG_ARCH_HIBERNATION_HEADER
+static int init_header_complete(struct swsusp_info *info)
+{
+	memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
+	info->version_code = LINUX_VERSION_CODE;
+	return 0;
+}
+
+static const char *check_image_kernel(struct swsusp_info *info)
+{
+	if (info->version_code != LINUX_VERSION_CODE)
+		return "kernel version";
+	if (strcmp(info->uts.sysname,init_utsname()->sysname))
+		return "system type";
+	if (strcmp(info->uts.release,init_utsname()->release))
+		return "kernel release";
+	if (strcmp(info->uts.version,init_utsname()->version))
+		return "version";
+	if (strcmp(info->uts.machine,init_utsname()->machine))
+		return "machine";
+	return NULL;
+}
+#endif /* CONFIG_ARCH_HIBERNATION_HEADER */
+
+unsigned long snapshot_get_image_size(void)
+{
+	return nr_copy_pages + nr_meta_pages + 1;
+}
+
+static int init_header(struct swsusp_info *info)
+{
+	memset(info, 0, sizeof(struct swsusp_info));
+	info->num_physpages = get_num_physpages();
+	info->image_pages = nr_copy_pages;
+	info->pages = snapshot_get_image_size();
+	info->size = info->pages;
+	info->size <<= PAGE_SHIFT;
+	return init_header_complete(info);
+}
+
+#define ENCODED_PFN_ZERO_FLAG ((unsigned long)1 << (BITS_PER_LONG - 1))
+#define ENCODED_PFN_MASK (~ENCODED_PFN_ZERO_FLAG)
+
+/**
+ * pack_pfns - Prepare PFNs for saving.
+ * @bm: Memory bitmap.
+ * @buf: Memory buffer to store the PFNs in.
+ * @zero_bm: Memory bitmap containing PFNs of zero pages.
+ *
+ * PFNs corresponding to set bits in @bm are stored in the area of memory
+ * pointed to by @buf (1 page at a time). Pages which were filled with only
+ * zeros will have the highest bit set in the packed format to distinguish
+ * them from PFNs which will be contained in the image file.
+ */
+static inline void pack_pfns(unsigned long *buf, struct memory_bitmap *bm,
+		struct memory_bitmap *zero_bm)
+{
+	int j;
+
+	for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
+		buf[j] = memory_bm_next_pfn(bm);
+		if (unlikely(buf[j] == BM_END_OF_MAP))
+			break;
+		if (memory_bm_test_bit(zero_bm, buf[j]))
+			buf[j] |= ENCODED_PFN_ZERO_FLAG;
+	}
+}
+
+/**
+ * snapshot_read_next - Get the address to read the next image page from.
+ * @handle: Snapshot handle to be used for the reading.
+ *
+ * On the first call, @handle should point to a zeroed snapshot_handle
+ * structure.  The structure gets populated then and a pointer to it should be
+ * passed to this function every next time.
+ *
+ * On success, the function returns a positive number.  Then, the caller
+ * is allowed to read up to the returned number of bytes from the memory
+ * location computed by the data_of() macro.
+ *
+ * The function returns 0 to indicate the end of the data stream condition,
+ * and negative numbers are returned on errors.  If that happens, the structure
+ * pointed to by @handle is not updated and should not be used any more.
+ */
+int snapshot_read_next(struct snapshot_handle *handle)
+{
+	if (handle->cur > nr_meta_pages + nr_copy_pages)
+		return 0;
+
+	if (!buffer) {
+		/* This makes the buffer be freed by swsusp_free() */
+		buffer = get_image_page(GFP_ATOMIC, PG_ANY);
+		if (!buffer)
+			return -ENOMEM;
+	}
+	if (!handle->cur) {
+		int error;
+
+		error = init_header((struct swsusp_info *)buffer);
+		if (error)
+			return error;
+		handle->buffer = buffer;
+		memory_bm_position_reset(&orig_bm);
+		memory_bm_position_reset(&copy_bm);
+	} else if (handle->cur <= nr_meta_pages) {
+		clear_page(buffer);
+		pack_pfns(buffer, &orig_bm, &zero_bm);
+	} else {
+		struct page *page;
+
+		page = pfn_to_page(memory_bm_next_pfn(&copy_bm));
+		if (PageHighMem(page)) {
+			/*
+			 * Highmem pages are copied to the buffer,
+			 * because we can't return with a kmapped
+			 * highmem page (we may not be called again).
+			 */
+			void *kaddr;
+
+			kaddr = kmap_atomic(page);
+			copy_page(buffer, kaddr);
+			kunmap_atomic(kaddr);
+			handle->buffer = buffer;
+		} else {
+			handle->buffer = page_address(page);
+		}
+	}
+	handle->cur++;
+	return PAGE_SIZE;
+}
+
+static void duplicate_memory_bitmap(struct memory_bitmap *dst,
+				    struct memory_bitmap *src)
+{
+	unsigned long pfn;
+
+	memory_bm_position_reset(src);
+	pfn = memory_bm_next_pfn(src);
+	while (pfn != BM_END_OF_MAP) {
+		memory_bm_set_bit(dst, pfn);
+		pfn = memory_bm_next_pfn(src);
+	}
+}
+
+/**
+ * mark_unsafe_pages - Mark pages that were used before hibernation.
+ *
+ * Mark the pages that cannot be used for storing the image during restoration,
+ * because they conflict with the pages that had been used before hibernation.
+ */
+static void mark_unsafe_pages(struct memory_bitmap *bm)
+{
+	unsigned long pfn;
+
+	/* Clear the "free"/"unsafe" bit for all PFNs */
+	memory_bm_position_reset(free_pages_map);
+	pfn = memory_bm_next_pfn(free_pages_map);
+	while (pfn != BM_END_OF_MAP) {
+		memory_bm_clear_current(free_pages_map);
+		pfn = memory_bm_next_pfn(free_pages_map);
+	}
+
+	/* Mark pages that correspond to the "original" PFNs as "unsafe" */
+	duplicate_memory_bitmap(free_pages_map, bm);
+
+	allocated_unsafe_pages = 0;
+}
+
+static int check_header(struct swsusp_info *info)
+{
+	const char *reason;
+
+	reason = check_image_kernel(info);
+	if (!reason && info->num_physpages != get_num_physpages())
+		reason = "memory size";
+	if (reason) {
+		pr_err("Image mismatch: %s\n", reason);
+		return -EPERM;
+	}
+	return 0;
+}
+
+/**
+ * load_header - Check the image header and copy the data from it.
+ */
+static int load_header(struct swsusp_info *info)
+{
+	int error;
+
+	restore_pblist = NULL;
+	error = check_header(info);
+	if (!error) {
+		nr_copy_pages = info->image_pages;
+		nr_meta_pages = info->pages - info->image_pages - 1;
+	}
+	return error;
+}
+
+/**
+ * unpack_orig_pfns - Set bits corresponding to given PFNs in a memory bitmap.
+ * @bm: Memory bitmap.
+ * @buf: Area of memory containing the PFNs.
+ * @zero_bm: Memory bitmap with the zero PFNs marked.
+ *
+ * For each element of the array pointed to by @buf (1 page at a time), set the
+ * corresponding bit in @bm. If the page was originally populated with only
+ * zeros then a corresponding bit will also be set in @zero_bm.
+ */
+static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm,
+		struct memory_bitmap *zero_bm)
+{
+	unsigned long decoded_pfn;
+        bool zero;
+	int j;
+
+	for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
+		if (unlikely(buf[j] == BM_END_OF_MAP))
+			break;
+
+		zero = !!(buf[j] & ENCODED_PFN_ZERO_FLAG);
+		decoded_pfn = buf[j] & ENCODED_PFN_MASK;
+		if (pfn_valid(decoded_pfn) && memory_bm_pfn_present(bm, decoded_pfn)) {
+			memory_bm_set_bit(bm, decoded_pfn);
+			if (zero) {
+				memory_bm_set_bit(zero_bm, decoded_pfn);
+				nr_zero_pages++;
+			}
+		} else {
+			if (!pfn_valid(decoded_pfn))
+				pr_err(FW_BUG "Memory map mismatch at 0x%llx after hibernation\n",
+				       (unsigned long long)PFN_PHYS(decoded_pfn));
+			return -EFAULT;
+		}
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_HIGHMEM
+/*
+ * struct highmem_pbe is used for creating the list of highmem pages that
+ * should be restored atomically during the resume from disk, because the page
+ * frames they have occupied before the suspend are in use.
+ */
+struct highmem_pbe {
+	struct page *copy_page;	/* data is here now */
+	struct page *orig_page;	/* data was here before the suspend */
+	struct highmem_pbe *next;
+};
+
+/*
+ * List of highmem PBEs needed for restoring the highmem pages that were
+ * allocated before the suspend and included in the suspend image, but have
+ * also been allocated by the "resume" kernel, so their contents cannot be
+ * written directly to their "original" page frames.
+ */
+static struct highmem_pbe *highmem_pblist;
+
+/**
+ * count_highmem_image_pages - Compute the number of highmem pages in the image.
+ * @bm: Memory bitmap.
+ *
+ * The bits in @bm that correspond to image pages are assumed to be set.
+ */
+static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
+{
+	unsigned long pfn;
+	unsigned int cnt = 0;
+
+	memory_bm_position_reset(bm);
+	pfn = memory_bm_next_pfn(bm);
+	while (pfn != BM_END_OF_MAP) {
+		if (PageHighMem(pfn_to_page(pfn)))
+			cnt++;
+
+		pfn = memory_bm_next_pfn(bm);
+	}
+	return cnt;
+}
+
+static unsigned int safe_highmem_pages;
+
+static struct memory_bitmap *safe_highmem_bm;
+
+/**
+ * prepare_highmem_image - Allocate memory for loading highmem data from image.
+ * @bm: Pointer to an uninitialized memory bitmap structure.
+ * @nr_highmem_p: Pointer to the number of highmem image pages.
+ *
+ * Try to allocate as many highmem pages as there are highmem image pages
+ * (@nr_highmem_p points to the variable containing the number of highmem image
+ * pages).  The pages that are "safe" (ie. will not be overwritten when the
+ * hibernation image is restored entirely) have the corresponding bits set in
+ * @bm (it must be uninitialized).
+ *
+ * NOTE: This function should not be called if there are no highmem image pages.
+ */
+static int prepare_highmem_image(struct memory_bitmap *bm,
+				 unsigned int *nr_highmem_p)
+{
+	unsigned int to_alloc;
+
+	if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
+		return -ENOMEM;
+
+	if (get_highmem_buffer(PG_SAFE))
+		return -ENOMEM;
+
+	to_alloc = count_free_highmem_pages();
+	if (to_alloc > *nr_highmem_p)
+		to_alloc = *nr_highmem_p;
+	else
+		*nr_highmem_p = to_alloc;
+
+	safe_highmem_pages = 0;
+	while (to_alloc-- > 0) {
+		struct page *page;
+
+		page = alloc_page(__GFP_HIGHMEM);
+		if (!swsusp_page_is_free(page)) {
+			/* The page is "safe", set its bit the bitmap */
+			memory_bm_set_bit(bm, page_to_pfn(page));
+			safe_highmem_pages++;
+		}
+		/* Mark the page as allocated */
+		swsusp_set_page_forbidden(page);
+		swsusp_set_page_free(page);
+	}
+	memory_bm_position_reset(bm);
+	safe_highmem_bm = bm;
+	return 0;
+}
+
+static struct page *last_highmem_page;
+
+/**
+ * get_highmem_page_buffer - Prepare a buffer to store a highmem image page.
+ *
+ * For a given highmem image page get a buffer that suspend_write_next() should
+ * return to its caller to write to.
+ *
+ * If the page is to be saved to its "original" page frame or a copy of
+ * the page is to be made in the highmem, @buffer is returned.  Otherwise,
+ * the copy of the page is to be made in normal memory, so the address of
+ * the copy is returned.
+ *
+ * If @buffer is returned, the caller of suspend_write_next() will write
+ * the page's contents to @buffer, so they will have to be copied to the
+ * right location on the next call to suspend_write_next() and it is done
+ * with the help of copy_last_highmem_page().  For this purpose, if
+ * @buffer is returned, @last_highmem_page is set to the page to which
+ * the data will have to be copied from @buffer.
+ */
+static void *get_highmem_page_buffer(struct page *page,
+				     struct chain_allocator *ca)
+{
+	struct highmem_pbe *pbe;
+	void *kaddr;
+
+	if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
+		/*
+		 * We have allocated the "original" page frame and we can
+		 * use it directly to store the loaded page.
+		 */
+		last_highmem_page = page;
+		return buffer;
+	}
+	/*
+	 * The "original" page frame has not been allocated and we have to
+	 * use a "safe" page frame to store the loaded page.
+	 */
+	pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
+	if (!pbe) {
+		swsusp_free();
+		return ERR_PTR(-ENOMEM);
+	}
+	pbe->orig_page = page;
+	if (safe_highmem_pages > 0) {
+		struct page *tmp;
+
+		/* Copy of the page will be stored in high memory */
+		kaddr = buffer;
+		tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
+		safe_highmem_pages--;
+		last_highmem_page = tmp;
+		pbe->copy_page = tmp;
+	} else {
+		/* Copy of the page will be stored in normal memory */
+		kaddr = __get_safe_page(ca->gfp_mask);
+		if (!kaddr)
+			return ERR_PTR(-ENOMEM);
+		pbe->copy_page = virt_to_page(kaddr);
+	}
+	pbe->next = highmem_pblist;
+	highmem_pblist = pbe;
+	return kaddr;
+}
+
+/**
+ * copy_last_highmem_page - Copy most the most recent highmem image page.
+ *
+ * Copy the contents of a highmem image from @buffer, where the caller of
+ * snapshot_write_next() has stored them, to the right location represented by
+ * @last_highmem_page .
+ */
+static void copy_last_highmem_page(void)
+{
+	if (last_highmem_page) {
+		void *dst;
+
+		dst = kmap_atomic(last_highmem_page);
+		copy_page(dst, buffer);
+		kunmap_atomic(dst);
+		last_highmem_page = NULL;
+	}
+}
+
+static inline int last_highmem_page_copied(void)
+{
+	return !last_highmem_page;
+}
+
+static inline void free_highmem_data(void)
+{
+	if (safe_highmem_bm)
+		memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR);
+
+	if (buffer)
+		free_image_page(buffer, PG_UNSAFE_CLEAR);
+}
+#else
+static unsigned int count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
+
+static inline int prepare_highmem_image(struct memory_bitmap *bm,
+					unsigned int *nr_highmem_p) { return 0; }
+
+static inline void *get_highmem_page_buffer(struct page *page,
+					    struct chain_allocator *ca)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+static inline void copy_last_highmem_page(void) {}
+static inline int last_highmem_page_copied(void) { return 1; }
+static inline void free_highmem_data(void) {}
+#endif /* CONFIG_HIGHMEM */
+
+#define PBES_PER_LINKED_PAGE	(LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
+
+/**
+ * prepare_image - Make room for loading hibernation image.
+ * @new_bm: Uninitialized memory bitmap structure.
+ * @bm: Memory bitmap with unsafe pages marked.
+ * @zero_bm: Memory bitmap containing the zero pages.
+ *
+ * Use @bm to mark the pages that will be overwritten in the process of
+ * restoring the system memory state from the suspend image ("unsafe" pages)
+ * and allocate memory for the image.
+ *
+ * The idea is to allocate a new memory bitmap first and then allocate
+ * as many pages as needed for image data, but without specifying what those
+ * pages will be used for just yet.  Instead, we mark them all as allocated and
+ * create a lists of "safe" pages to be used later.  On systems with high
+ * memory a list of "safe" highmem pages is created too.
+ *
+ * Because it was not known which pages were unsafe when @zero_bm was created,
+ * make a copy of it and recreate it within safe pages.
+ */
+static int prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm,
+		struct memory_bitmap *zero_bm)
+{
+	unsigned int nr_pages, nr_highmem;
+	struct memory_bitmap tmp;
+	struct linked_page *lp;
+	int error;
+
+	/* If there is no highmem, the buffer will not be necessary */
+	free_image_page(buffer, PG_UNSAFE_CLEAR);
+	buffer = NULL;
+
+	nr_highmem = count_highmem_image_pages(bm);
+	mark_unsafe_pages(bm);
+
+	error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);
+	if (error)
+		goto Free;
+
+	duplicate_memory_bitmap(new_bm, bm);
+	memory_bm_free(bm, PG_UNSAFE_KEEP);
+
+	/* Make a copy of zero_bm so it can be created in safe pages */
+	error = memory_bm_create(&tmp, GFP_ATOMIC, PG_SAFE);
+	if (error)
+		goto Free;
+
+	duplicate_memory_bitmap(&tmp, zero_bm);
+	memory_bm_free(zero_bm, PG_UNSAFE_KEEP);
+
+	/* Recreate zero_bm in safe pages */
+	error = memory_bm_create(zero_bm, GFP_ATOMIC, PG_SAFE);
+	if (error)
+		goto Free;
+
+	duplicate_memory_bitmap(zero_bm, &tmp);
+	memory_bm_free(&tmp, PG_UNSAFE_CLEAR);
+	/* At this point zero_bm is in safe pages and it can be used for restoring. */
+
+	if (nr_highmem > 0) {
+		error = prepare_highmem_image(bm, &nr_highmem);
+		if (error)
+			goto Free;
+	}
+	/*
+	 * Reserve some safe pages for potential later use.
+	 *
+	 * NOTE: This way we make sure there will be enough safe pages for the
+	 * chain_alloc() in get_buffer().  It is a bit wasteful, but
+	 * nr_copy_pages cannot be greater than 50% of the memory anyway.
+	 *
+	 * nr_copy_pages cannot be less than allocated_unsafe_pages too.
+	 */
+	nr_pages = (nr_zero_pages + nr_copy_pages) - nr_highmem - allocated_unsafe_pages;
+	nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
+	while (nr_pages > 0) {
+		lp = get_image_page(GFP_ATOMIC, PG_SAFE);
+		if (!lp) {
+			error = -ENOMEM;
+			goto Free;
+		}
+		lp->next = safe_pages_list;
+		safe_pages_list = lp;
+		nr_pages--;
+	}
+	/* Preallocate memory for the image */
+	nr_pages = (nr_zero_pages + nr_copy_pages) - nr_highmem - allocated_unsafe_pages;
+	while (nr_pages > 0) {
+		lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
+		if (!lp) {
+			error = -ENOMEM;
+			goto Free;
+		}
+		if (!swsusp_page_is_free(virt_to_page(lp))) {
+			/* The page is "safe", add it to the list */
+			lp->next = safe_pages_list;
+			safe_pages_list = lp;
+		}
+		/* Mark the page as allocated */
+		swsusp_set_page_forbidden(virt_to_page(lp));
+		swsusp_set_page_free(virt_to_page(lp));
+		nr_pages--;
+	}
+	return 0;
+
+ Free:
+	swsusp_free();
+	return error;
+}
+
+/**
+ * get_buffer - Get the address to store the next image data page.
+ *
+ * Get the address that snapshot_write_next() should return to its caller to
+ * write to.
+ */
+static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
+{
+	struct pbe *pbe;
+	struct page *page;
+	unsigned long pfn = memory_bm_next_pfn(bm);
+
+	if (pfn == BM_END_OF_MAP)
+		return ERR_PTR(-EFAULT);
+
+	page = pfn_to_page(pfn);
+	if (PageHighMem(page))
+		return get_highmem_page_buffer(page, ca);
+
+	if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page))
+		/*
+		 * We have allocated the "original" page frame and we can
+		 * use it directly to store the loaded page.
+		 */
+		return page_address(page);
+
+	/*
+	 * The "original" page frame has not been allocated and we have to
+	 * use a "safe" page frame to store the loaded page.
+	 */
+	pbe = chain_alloc(ca, sizeof(struct pbe));
+	if (!pbe) {
+		swsusp_free();
+		return ERR_PTR(-ENOMEM);
+	}
+	pbe->orig_address = page_address(page);
+	pbe->address = __get_safe_page(ca->gfp_mask);
+	if (!pbe->address)
+		return ERR_PTR(-ENOMEM);
+	pbe->next = restore_pblist;
+	restore_pblist = pbe;
+	return pbe->address;
+}
+
+/**
+ * snapshot_write_next - Get the address to store the next image page.
+ * @handle: Snapshot handle structure to guide the writing.
+ *
+ * On the first call, @handle should point to a zeroed snapshot_handle
+ * structure.  The structure gets populated then and a pointer to it should be
+ * passed to this function every next time.
+ *
+ * On success, the function returns a positive number.  Then, the caller
+ * is allowed to write up to the returned number of bytes to the memory
+ * location computed by the data_of() macro.
+ *
+ * The function returns 0 to indicate the "end of file" condition.  Negative
+ * numbers are returned on errors, in which cases the structure pointed to by
+ * @handle is not updated and should not be used any more.
+ */
+int snapshot_write_next(struct snapshot_handle *handle)
+{
+	static struct chain_allocator ca;
+	int error = 0;
+
+next:
+	/* Check if we have already loaded the entire image */
+	if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages + nr_zero_pages)
+		return 0;
+
+	if (!handle->cur) {
+		if (!buffer)
+			/* This makes the buffer be freed by swsusp_free() */
+			buffer = get_image_page(GFP_ATOMIC, PG_ANY);
+
+		if (!buffer)
+			return -ENOMEM;
+
+		handle->buffer = buffer;
+	} else if (handle->cur == 1) {
+		error = load_header(buffer);
+		if (error)
+			return error;
+
+		safe_pages_list = NULL;
+
+		error = memory_bm_create(&copy_bm, GFP_ATOMIC, PG_ANY);
+		if (error)
+			return error;
+
+		error = memory_bm_create(&zero_bm, GFP_ATOMIC, PG_ANY);
+		if (error)
+			return error;
+
+		nr_zero_pages = 0;
+
+		hibernate_restore_protection_begin();
+	} else if (handle->cur <= nr_meta_pages + 1) {
+		error = unpack_orig_pfns(buffer, &copy_bm, &zero_bm);
+		if (error)
+			return error;
+
+		if (handle->cur == nr_meta_pages + 1) {
+			error = prepare_image(&orig_bm, &copy_bm, &zero_bm);
+			if (error)
+				return error;
+
+			chain_init(&ca, GFP_ATOMIC, PG_SAFE);
+			memory_bm_position_reset(&orig_bm);
+			memory_bm_position_reset(&zero_bm);
+			restore_pblist = NULL;
+			handle->buffer = get_buffer(&orig_bm, &ca);
+			if (IS_ERR(handle->buffer))
+				return PTR_ERR(handle->buffer);
+		}
+	} else {
+		copy_last_highmem_page();
+		hibernate_restore_protect_page(handle->buffer);
+		handle->buffer = get_buffer(&orig_bm, &ca);
+		if (IS_ERR(handle->buffer))
+			return PTR_ERR(handle->buffer);
+	}
+	handle->sync_read = (handle->buffer == buffer);
+	handle->cur++;
+
+	/* Zero pages were not included in the image, memset it and move on. */
+	if (handle->cur > nr_meta_pages + 1 &&
+	    memory_bm_test_bit(&zero_bm, memory_bm_get_current(&orig_bm))) {
+		memset(handle->buffer, 0, PAGE_SIZE);
+		goto next;
+	}
+
+	return PAGE_SIZE;
+}
+
+/**
+ * snapshot_write_finalize - Complete the loading of a hibernation image.
+ *
+ * Must be called after the last call to snapshot_write_next() in case the last
+ * page in the image happens to be a highmem page and its contents should be
+ * stored in highmem.  Additionally, it recycles bitmap memory that's not
+ * necessary any more.
+ */
+void snapshot_write_finalize(struct snapshot_handle *handle)
+{
+	copy_last_highmem_page();
+	hibernate_restore_protect_page(handle->buffer);
+	/* Do that only if we have loaded the image entirely */
+	if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages + nr_zero_pages) {
+		memory_bm_recycle(&orig_bm);
+		free_highmem_data();
+	}
+}
+
+int snapshot_image_loaded(struct snapshot_handle *handle)
+{
+	return !(!nr_copy_pages || !last_highmem_page_copied() ||
+			handle->cur <= nr_meta_pages + nr_copy_pages + nr_zero_pages);
+}
+
+#ifdef CONFIG_HIGHMEM
+/* Assumes that @buf is ready and points to a "safe" page */
+static inline void swap_two_pages_data(struct page *p1, struct page *p2,
+				       void *buf)
+{
+	void *kaddr1, *kaddr2;
+
+	kaddr1 = kmap_atomic(p1);
+	kaddr2 = kmap_atomic(p2);
+	copy_page(buf, kaddr1);
+	copy_page(kaddr1, kaddr2);
+	copy_page(kaddr2, buf);
+	kunmap_atomic(kaddr2);
+	kunmap_atomic(kaddr1);
+}
+
+/**
+ * restore_highmem - Put highmem image pages into their original locations.
+ *
+ * For each highmem page that was in use before hibernation and is included in
+ * the image, and also has been allocated by the "restore" kernel, swap its
+ * current contents with the previous (ie. "before hibernation") ones.
+ *
+ * If the restore eventually fails, we can call this function once again and
+ * restore the highmem state as seen by the restore kernel.
+ */
+int restore_highmem(void)
+{
+	struct highmem_pbe *pbe = highmem_pblist;
+	void *buf;
+
+	if (!pbe)
+		return 0;
+
+	buf = get_image_page(GFP_ATOMIC, PG_SAFE);
+	if (!buf)
+		return -ENOMEM;
+
+	while (pbe) {
+		swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf);
+		pbe = pbe->next;
+	}
+	free_image_page(buf, PG_UNSAFE_CLEAR);
+	return 0;
+}
+#endif /* CONFIG_HIGHMEM */
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
new file mode 100644
index 000000000..fa3bf161d
--- /dev/null
+++ b/kernel/power/suspend.c
@@ -0,0 +1,629 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * kernel/power/suspend.c - Suspend to RAM and standby functionality.
+ *
+ * Copyright (c) 2003 Patrick Mochel
+ * Copyright (c) 2003 Open Source Development Lab
+ * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
+ */
+
+#define pr_fmt(fmt) "PM: " fmt
+
+#include <linux/string.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/cpu.h>
+#include <linux/cpuidle.h>
+#include <linux/gfp.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/suspend.h>
+#include <linux/syscore_ops.h>
+#include <linux/swait.h>
+#include <linux/ftrace.h>
+#include <trace/events/power.h>
+#include <linux/compiler.h>
+#include <linux/moduleparam.h>
+
+#include "power.h"
+
+const char * const pm_labels[] = {
+	[PM_SUSPEND_TO_IDLE] = "freeze",
+	[PM_SUSPEND_STANDBY] = "standby",
+	[PM_SUSPEND_MEM] = "mem",
+};
+const char *pm_states[PM_SUSPEND_MAX];
+static const char * const mem_sleep_labels[] = {
+	[PM_SUSPEND_TO_IDLE] = "s2idle",
+	[PM_SUSPEND_STANDBY] = "shallow",
+	[PM_SUSPEND_MEM] = "deep",
+};
+const char *mem_sleep_states[PM_SUSPEND_MAX];
+
+suspend_state_t mem_sleep_current = PM_SUSPEND_TO_IDLE;
+suspend_state_t mem_sleep_default = PM_SUSPEND_MAX;
+suspend_state_t pm_suspend_target_state;
+EXPORT_SYMBOL_GPL(pm_suspend_target_state);
+
+unsigned int pm_suspend_global_flags;
+EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
+
+static const struct platform_suspend_ops *suspend_ops;
+static const struct platform_s2idle_ops *s2idle_ops;
+static DECLARE_SWAIT_QUEUE_HEAD(s2idle_wait_head);
+
+enum s2idle_states __read_mostly s2idle_state;
+static DEFINE_RAW_SPINLOCK(s2idle_lock);
+
+/**
+ * pm_suspend_default_s2idle - Check if suspend-to-idle is the default suspend.
+ *
+ * Return 'true' if suspend-to-idle has been selected as the default system
+ * suspend method.
+ */
+bool pm_suspend_default_s2idle(void)
+{
+	return mem_sleep_current == PM_SUSPEND_TO_IDLE;
+}
+EXPORT_SYMBOL_GPL(pm_suspend_default_s2idle);
+
+void s2idle_set_ops(const struct platform_s2idle_ops *ops)
+{
+	unsigned int sleep_flags;
+
+	sleep_flags = lock_system_sleep();
+	s2idle_ops = ops;
+	unlock_system_sleep(sleep_flags);
+}
+
+static void s2idle_begin(void)
+{
+	s2idle_state = S2IDLE_STATE_NONE;
+}
+
+static void s2idle_enter(void)
+{
+	trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
+
+	raw_spin_lock_irq(&s2idle_lock);
+	if (pm_wakeup_pending())
+		goto out;
+
+	s2idle_state = S2IDLE_STATE_ENTER;
+	raw_spin_unlock_irq(&s2idle_lock);
+
+	cpus_read_lock();
+
+	/* Push all the CPUs into the idle loop. */
+	wake_up_all_idle_cpus();
+	/* Make the current CPU wait so it can enter the idle loop too. */
+	swait_event_exclusive(s2idle_wait_head,
+		    s2idle_state == S2IDLE_STATE_WAKE);
+
+	cpus_read_unlock();
+
+	raw_spin_lock_irq(&s2idle_lock);
+
+ out:
+	s2idle_state = S2IDLE_STATE_NONE;
+	raw_spin_unlock_irq(&s2idle_lock);
+
+	trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false);
+}
+
+static void s2idle_loop(void)
+{
+	pm_pr_dbg("suspend-to-idle\n");
+
+	/*
+	 * Suspend-to-idle equals:
+	 * frozen processes + suspended devices + idle processors.
+	 * Thus s2idle_enter() should be called right after all devices have
+	 * been suspended.
+	 *
+	 * Wakeups during the noirq suspend of devices may be spurious, so try
+	 * to avoid them upfront.
+	 */
+	for (;;) {
+		if (s2idle_ops && s2idle_ops->wake) {
+			if (s2idle_ops->wake())
+				break;
+		} else if (pm_wakeup_pending()) {
+			break;
+		}
+
+		if (s2idle_ops && s2idle_ops->check)
+			s2idle_ops->check();
+
+		s2idle_enter();
+	}
+
+	pm_pr_dbg("resume from suspend-to-idle\n");
+}
+
+void s2idle_wake(void)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&s2idle_lock, flags);
+	if (s2idle_state > S2IDLE_STATE_NONE) {
+		s2idle_state = S2IDLE_STATE_WAKE;
+		swake_up_one(&s2idle_wait_head);
+	}
+	raw_spin_unlock_irqrestore(&s2idle_lock, flags);
+}
+EXPORT_SYMBOL_GPL(s2idle_wake);
+
+static bool valid_state(suspend_state_t state)
+{
+	/*
+	 * The PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states require low-level
+	 * support and need to be valid to the low-level implementation.
+	 *
+	 * No ->valid() or ->enter() callback implies that none are valid.
+	 */
+	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state) &&
+		suspend_ops->enter;
+}
+
+void __init pm_states_init(void)
+{
+	/* "mem" and "freeze" are always present in /sys/power/state. */
+	pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
+	pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE];
+	/*
+	 * Suspend-to-idle should be supported even without any suspend_ops,
+	 * initialize mem_sleep_states[] accordingly here.
+	 */
+	mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];
+}
+
+static int __init mem_sleep_default_setup(char *str)
+{
+	suspend_state_t state;
+
+	for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++)
+		if (mem_sleep_labels[state] &&
+		    !strcmp(str, mem_sleep_labels[state])) {
+			mem_sleep_default = state;
+			break;
+		}
+
+	return 1;
+}
+__setup("mem_sleep_default=", mem_sleep_default_setup);
+
+/**
+ * suspend_set_ops - Set the global suspend method table.
+ * @ops: Suspend operations to use.
+ */
+void suspend_set_ops(const struct platform_suspend_ops *ops)
+{
+	unsigned int sleep_flags;
+
+	sleep_flags = lock_system_sleep();
+
+	suspend_ops = ops;
+
+	if (valid_state(PM_SUSPEND_STANDBY)) {
+		mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
+		pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
+		if (mem_sleep_default == PM_SUSPEND_STANDBY)
+			mem_sleep_current = PM_SUSPEND_STANDBY;
+	}
+	if (valid_state(PM_SUSPEND_MEM)) {
+		mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
+		if (mem_sleep_default >= PM_SUSPEND_MEM)
+			mem_sleep_current = PM_SUSPEND_MEM;
+	}
+
+	unlock_system_sleep(sleep_flags);
+}
+EXPORT_SYMBOL_GPL(suspend_set_ops);
+
+/**
+ * suspend_valid_only_mem - Generic memory-only valid callback.
+ * @state: Target system sleep state.
+ *
+ * Platform drivers that implement mem suspend only and only need to check for
+ * that in their .valid() callback can use this instead of rolling their own
+ * .valid() callback.
+ */
+int suspend_valid_only_mem(suspend_state_t state)
+{
+	return state == PM_SUSPEND_MEM;
+}
+EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
+
+static bool sleep_state_supported(suspend_state_t state)
+{
+	return state == PM_SUSPEND_TO_IDLE ||
+	       (valid_state(state) && !cxl_mem_active());
+}
+
+static int platform_suspend_prepare(suspend_state_t state)
+{
+	return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?
+		suspend_ops->prepare() : 0;
+}
+
+static int platform_suspend_prepare_late(suspend_state_t state)
+{
+	return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?
+		s2idle_ops->prepare() : 0;
+}
+
+static int platform_suspend_prepare_noirq(suspend_state_t state)
+{
+	if (state == PM_SUSPEND_TO_IDLE)
+		return s2idle_ops && s2idle_ops->prepare_late ?
+			s2idle_ops->prepare_late() : 0;
+
+	return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0;
+}
+
+static void platform_resume_noirq(suspend_state_t state)
+{
+	if (state == PM_SUSPEND_TO_IDLE) {
+		if (s2idle_ops && s2idle_ops->restore_early)
+			s2idle_ops->restore_early();
+	} else if (suspend_ops->wake) {
+		suspend_ops->wake();
+	}
+}
+
+static void platform_resume_early(suspend_state_t state)
+{
+	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)
+		s2idle_ops->restore();
+}
+
+static void platform_resume_finish(suspend_state_t state)
+{
+	if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)
+		suspend_ops->finish();
+}
+
+static int platform_suspend_begin(suspend_state_t state)
+{
+	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)
+		return s2idle_ops->begin();
+	else if (suspend_ops && suspend_ops->begin)
+		return suspend_ops->begin(state);
+	else
+		return 0;
+}
+
+static void platform_resume_end(suspend_state_t state)
+{
+	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)
+		s2idle_ops->end();
+	else if (suspend_ops && suspend_ops->end)
+		suspend_ops->end();
+}
+
+static void platform_recover(suspend_state_t state)
+{
+	if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)
+		suspend_ops->recover();
+}
+
+static bool platform_suspend_again(suspend_state_t state)
+{
+	return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?
+		suspend_ops->suspend_again() : false;
+}
+
+#ifdef CONFIG_PM_DEBUG
+static unsigned int pm_test_delay = 5;
+module_param(pm_test_delay, uint, 0644);
+MODULE_PARM_DESC(pm_test_delay,
+		 "Number of seconds to wait before resuming from suspend test");
+#endif
+
+static int suspend_test(int level)
+{
+#ifdef CONFIG_PM_DEBUG
+	if (pm_test_level == level) {
+		pr_info("suspend debug: Waiting for %d second(s).\n",
+				pm_test_delay);
+		mdelay(pm_test_delay * 1000);
+		return 1;
+	}
+#endif /* !CONFIG_PM_DEBUG */
+	return 0;
+}
+
+/**
+ * suspend_prepare - Prepare for entering system sleep state.
+ * @state: Target system sleep state.
+ *
+ * Common code run for every system sleep state that can be entered (except for
+ * hibernation).  Run suspend notifiers, allocate the "suspend" console and
+ * freeze processes.
+ */
+static int suspend_prepare(suspend_state_t state)
+{
+	int error;
+
+	if (!sleep_state_supported(state))
+		return -EPERM;
+
+	pm_prepare_console();
+
+	error = pm_notifier_call_chain_robust(PM_SUSPEND_PREPARE, PM_POST_SUSPEND);
+	if (error)
+		goto Restore;
+
+	trace_suspend_resume(TPS("freeze_processes"), 0, true);
+	error = suspend_freeze_processes();
+	trace_suspend_resume(TPS("freeze_processes"), 0, false);
+	if (!error)
+		return 0;
+
+	suspend_stats.failed_freeze++;
+	dpm_save_failed_step(SUSPEND_FREEZE);
+	pm_notifier_call_chain(PM_POST_SUSPEND);
+ Restore:
+	pm_restore_console();
+	return error;
+}
+
+/* default implementation */
+void __weak arch_suspend_disable_irqs(void)
+{
+	local_irq_disable();
+}
+
+/* default implementation */
+void __weak arch_suspend_enable_irqs(void)
+{
+	local_irq_enable();
+}
+
+/**
+ * suspend_enter - Make the system enter the given sleep state.
+ * @state: System sleep state to enter.
+ * @wakeup: Returns information that the sleep state should not be re-entered.
+ *
+ * This function should be called after devices have been suspended.
+ */
+static int suspend_enter(suspend_state_t state, bool *wakeup)
+{
+	int error;
+
+	error = platform_suspend_prepare(state);
+	if (error)
+		goto Platform_finish;
+
+	error = dpm_suspend_late(PMSG_SUSPEND);
+	if (error) {
+		pr_err("late suspend of devices failed\n");
+		goto Platform_finish;
+	}
+	error = platform_suspend_prepare_late(state);
+	if (error)
+		goto Devices_early_resume;
+
+	error = dpm_suspend_noirq(PMSG_SUSPEND);
+	if (error) {
+		pr_err("noirq suspend of devices failed\n");
+		goto Platform_early_resume;
+	}
+	error = platform_suspend_prepare_noirq(state);
+	if (error)
+		goto Platform_wake;
+
+	if (suspend_test(TEST_PLATFORM))
+		goto Platform_wake;
+
+	if (state == PM_SUSPEND_TO_IDLE) {
+		s2idle_loop();
+		goto Platform_wake;
+	}
+
+	error = pm_sleep_disable_secondary_cpus();
+	if (error || suspend_test(TEST_CPUS))
+		goto Enable_cpus;
+
+	arch_suspend_disable_irqs();
+	BUG_ON(!irqs_disabled());
+
+	system_state = SYSTEM_SUSPEND;
+
+	error = syscore_suspend();
+	if (!error) {
+		*wakeup = pm_wakeup_pending();
+		if (!(suspend_test(TEST_CORE) || *wakeup)) {
+			trace_suspend_resume(TPS("machine_suspend"),
+				state, true);
+			error = suspend_ops->enter(state);
+			trace_suspend_resume(TPS("machine_suspend"),
+				state, false);
+		} else if (*wakeup) {
+			error = -EBUSY;
+		}
+		syscore_resume();
+	}
+
+	system_state = SYSTEM_RUNNING;
+
+	arch_suspend_enable_irqs();
+	BUG_ON(irqs_disabled());
+
+ Enable_cpus:
+	pm_sleep_enable_secondary_cpus();
+
+ Platform_wake:
+	platform_resume_noirq(state);
+	dpm_resume_noirq(PMSG_RESUME);
+
+ Platform_early_resume:
+	platform_resume_early(state);
+
+ Devices_early_resume:
+	dpm_resume_early(PMSG_RESUME);
+
+ Platform_finish:
+	platform_resume_finish(state);
+	return error;
+}
+
+/**
+ * suspend_devices_and_enter - Suspend devices and enter system sleep state.
+ * @state: System sleep state to enter.
+ */
+int suspend_devices_and_enter(suspend_state_t state)
+{
+	int error;
+	bool wakeup = false;
+
+	if (!sleep_state_supported(state))
+		return -ENOSYS;
+
+	pm_suspend_target_state = state;
+
+	if (state == PM_SUSPEND_TO_IDLE)
+		pm_set_suspend_no_platform();
+
+	error = platform_suspend_begin(state);
+	if (error)
+		goto Close;
+
+	suspend_console();
+	suspend_test_start();
+	error = dpm_suspend_start(PMSG_SUSPEND);
+	if (error) {
+		pr_err("Some devices failed to suspend, or early wake event detected\n");
+		goto Recover_platform;
+	}
+	suspend_test_finish("suspend devices");
+	if (suspend_test(TEST_DEVICES))
+		goto Recover_platform;
+
+	do {
+		error = suspend_enter(state, &wakeup);
+	} while (!error && !wakeup && platform_suspend_again(state));
+
+ Resume_devices:
+	suspend_test_start();
+	dpm_resume_end(PMSG_RESUME);
+	suspend_test_finish("resume devices");
+	trace_suspend_resume(TPS("resume_console"), state, true);
+	resume_console();
+	trace_suspend_resume(TPS("resume_console"), state, false);
+
+ Close:
+	platform_resume_end(state);
+	pm_suspend_target_state = PM_SUSPEND_ON;
+	return error;
+
+ Recover_platform:
+	platform_recover(state);
+	goto Resume_devices;
+}
+
+/**
+ * suspend_finish - Clean up before finishing the suspend sequence.
+ *
+ * Call platform code to clean up, restart processes, and free the console that
+ * we've allocated. This routine is not called for hibernation.
+ */
+static void suspend_finish(void)
+{
+	suspend_thaw_processes();
+	pm_notifier_call_chain(PM_POST_SUSPEND);
+	pm_restore_console();
+}
+
+/**
+ * enter_state - Do common work needed to enter system sleep state.
+ * @state: System sleep state to enter.
+ *
+ * Make sure that no one else is trying to put the system into a sleep state.
+ * Fail if that's not the case.  Otherwise, prepare for system suspend, make the
+ * system enter the given sleep state and clean up after wakeup.
+ */
+static int enter_state(suspend_state_t state)
+{
+	int error;
+
+	trace_suspend_resume(TPS("suspend_enter"), state, true);
+	if (state == PM_SUSPEND_TO_IDLE) {
+#ifdef CONFIG_PM_DEBUG
+		if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
+			pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
+			return -EAGAIN;
+		}
+#endif
+	} else if (!valid_state(state)) {
+		return -EINVAL;
+	}
+	if (!mutex_trylock(&system_transition_mutex))
+		return -EBUSY;
+
+	if (state == PM_SUSPEND_TO_IDLE)
+		s2idle_begin();
+
+	if (sync_on_suspend_enabled) {
+		trace_suspend_resume(TPS("sync_filesystems"), 0, true);
+		ksys_sync_helper();
+		trace_suspend_resume(TPS("sync_filesystems"), 0, false);
+	}
+
+	pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
+	pm_suspend_clear_flags();
+	error = suspend_prepare(state);
+	if (error)
+		goto Unlock;
+
+	if (suspend_test(TEST_FREEZER))
+		goto Finish;
+
+	trace_suspend_resume(TPS("suspend_enter"), state, false);
+	pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
+	pm_restrict_gfp_mask();
+	error = suspend_devices_and_enter(state);
+	pm_restore_gfp_mask();
+
+ Finish:
+	events_check_enabled = false;
+	pm_pr_dbg("Finishing wakeup.\n");
+	suspend_finish();
+ Unlock:
+	mutex_unlock(&system_transition_mutex);
+	return error;
+}
+
+/**
+ * pm_suspend - Externally visible function for suspending the system.
+ * @state: System sleep state to enter.
+ *
+ * Check if the value of @state represents one of the supported states,
+ * execute enter_state() and update system suspend statistics.
+ */
+int pm_suspend(suspend_state_t state)
+{
+	int error;
+
+	if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
+		return -EINVAL;
+
+	pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
+	error = enter_state(state);
+	if (error) {
+		suspend_stats.fail++;
+		dpm_save_failed_errno(error);
+	} else {
+		suspend_stats.success++;
+	}
+	pr_info("suspend exit\n");
+	return error;
+}
+EXPORT_SYMBOL(pm_suspend);
diff --git a/kernel/power/suspend_test.c b/kernel/power/suspend_test.c
new file mode 100644
index 000000000..b663a97f5
--- /dev/null
+++ b/kernel/power/suspend_test.c
@@ -0,0 +1,219 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * kernel/power/suspend_test.c - Suspend to RAM and standby test facility.
+ *
+ * Copyright (c) 2009 Pavel Machek <pavel@ucw.cz>
+ */
+
+#include <linux/init.h>
+#include <linux/rtc.h>
+
+#include "power.h"
+
+/*
+ * We test the system suspend code by setting an RTC wakealarm a short
+ * time in the future, then suspending.  Suspending the devices won't
+ * normally take long ... some systems only need a few milliseconds.
+ *
+ * The time it takes is system-specific though, so when we test this
+ * during system bootup we allow a LOT of time.
+ */
+#define TEST_SUSPEND_SECONDS	10
+
+static unsigned long suspend_test_start_time;
+static u32 test_repeat_count_max = 1;
+static u32 test_repeat_count_current;
+
+void suspend_test_start(void)
+{
+	/* FIXME Use better timebase than "jiffies", ideally a clocksource.
+	 * What we want is a hardware counter that will work correctly even
+	 * during the irqs-are-off stages of the suspend/resume cycle...
+	 */
+	suspend_test_start_time = jiffies;
+}
+
+void suspend_test_finish(const char *label)
+{
+	long nj = jiffies - suspend_test_start_time;
+	unsigned msec;
+
+	msec = jiffies_to_msecs(abs(nj));
+	pr_info("PM: %s took %d.%03d seconds\n", label,
+			msec / 1000, msec % 1000);
+
+	/* Warning on suspend means the RTC alarm period needs to be
+	 * larger -- the system was sooo slooowwww to suspend that the
+	 * alarm (should have) fired before the system went to sleep!
+	 *
+	 * Warning on either suspend or resume also means the system
+	 * has some performance issues.  The stack dump of a WARN_ON
+	 * is more likely to get the right attention than a printk...
+	 */
+	WARN(msec > (TEST_SUSPEND_SECONDS * 1000),
+	     "Component: %s, time: %u\n", label, msec);
+}
+
+/*
+ * To test system suspend, we need a hands-off mechanism to resume the
+ * system.  RTCs wake alarms are a common self-contained mechanism.
+ */
+
+static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state)
+{
+	static char err_readtime[] __initdata =
+		KERN_ERR "PM: can't read %s time, err %d\n";
+	static char err_wakealarm [] __initdata =
+		KERN_ERR "PM: can't set %s wakealarm, err %d\n";
+	static char err_suspend[] __initdata =
+		KERN_ERR "PM: suspend test failed, error %d\n";
+	static char info_test[] __initdata =
+		KERN_INFO "PM: test RTC wakeup from '%s' suspend\n";
+
+	time64_t		now;
+	struct rtc_wkalrm	alm;
+	int			status;
+
+	/* this may fail if the RTC hasn't been initialized */
+repeat:
+	status = rtc_read_time(rtc, &alm.time);
+	if (status < 0) {
+		printk(err_readtime, dev_name(&rtc->dev), status);
+		return;
+	}
+	now = rtc_tm_to_time64(&alm.time);
+
+	memset(&alm, 0, sizeof alm);
+	rtc_time64_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time);
+	alm.enabled = true;
+
+	status = rtc_set_alarm(rtc, &alm);
+	if (status < 0) {
+		printk(err_wakealarm, dev_name(&rtc->dev), status);
+		return;
+	}
+
+	if (state == PM_SUSPEND_MEM) {
+		printk(info_test, pm_states[state]);
+		status = pm_suspend(state);
+		if (status == -ENODEV)
+			state = PM_SUSPEND_STANDBY;
+	}
+	if (state == PM_SUSPEND_STANDBY) {
+		printk(info_test, pm_states[state]);
+		status = pm_suspend(state);
+		if (status < 0)
+			state = PM_SUSPEND_TO_IDLE;
+	}
+	if (state == PM_SUSPEND_TO_IDLE) {
+		printk(info_test, pm_states[state]);
+		status = pm_suspend(state);
+	}
+
+	if (status < 0)
+		printk(err_suspend, status);
+
+	test_repeat_count_current++;
+	if (test_repeat_count_current < test_repeat_count_max)
+		goto repeat;
+
+	/* Some platforms can't detect that the alarm triggered the
+	 * wakeup, or (accordingly) disable it after it afterwards.
+	 * It's supposed to give oneshot behavior; cope.
+	 */
+	alm.enabled = false;
+	rtc_set_alarm(rtc, &alm);
+}
+
+static int __init has_wakealarm(struct device *dev, const void *data)
+{
+	struct rtc_device *candidate = to_rtc_device(dev);
+
+	if (!test_bit(RTC_FEATURE_ALARM, candidate->features))
+		return 0;
+	if (!device_may_wakeup(candidate->dev.parent))
+		return 0;
+
+	return 1;
+}
+
+/*
+ * Kernel options like "test_suspend=mem" force suspend/resume sanity tests
+ * at startup time.  They're normally disabled, for faster boot and because
+ * we can't know which states really work on this particular system.
+ */
+static const char *test_state_label __initdata;
+
+static char warn_bad_state[] __initdata =
+	KERN_WARNING "PM: can't test '%s' suspend state\n";
+
+static int __init setup_test_suspend(char *value)
+{
+	int i;
+	char *repeat;
+	char *suspend_type;
+
+	/* example : "=mem[,N]" ==> "mem[,N]" */
+	value++;
+	suspend_type = strsep(&value, ",");
+	if (!suspend_type)
+		return 1;
+
+	repeat = strsep(&value, ",");
+	if (repeat) {
+		if (kstrtou32(repeat, 0, &test_repeat_count_max))
+			return 1;
+	}
+
+	for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
+		if (!strcmp(pm_labels[i], suspend_type)) {
+			test_state_label = pm_labels[i];
+			return 1;
+		}
+
+	printk(warn_bad_state, suspend_type);
+	return 1;
+}
+__setup("test_suspend", setup_test_suspend);
+
+static int __init test_suspend(void)
+{
+	static char		warn_no_rtc[] __initdata =
+		KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n";
+
+	struct rtc_device	*rtc = NULL;
+	struct device		*dev;
+	suspend_state_t test_state;
+
+	/* PM is initialized by now; is that state testable? */
+	if (!test_state_label)
+		return 0;
+
+	for (test_state = PM_SUSPEND_MIN; test_state < PM_SUSPEND_MAX; test_state++) {
+		const char *state_label = pm_states[test_state];
+
+		if (state_label && !strcmp(test_state_label, state_label))
+			break;
+	}
+	if (test_state == PM_SUSPEND_MAX) {
+		printk(warn_bad_state, test_state_label);
+		return 0;
+	}
+
+	/* RTCs have initialized by now too ... can we use one? */
+	dev = class_find_device(rtc_class, NULL, NULL, has_wakealarm);
+	if (dev) {
+		rtc = rtc_class_open(dev_name(dev));
+		put_device(dev);
+	}
+	if (!rtc) {
+		printk(warn_no_rtc);
+		return 0;
+	}
+
+	/* go for it */
+	test_wakealarm(rtc, test_state);
+	rtc_class_close(rtc);
+	return 0;
+}
+late_initcall(test_suspend);
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
new file mode 100644
index 000000000..d71c59055
--- /dev/null
+++ b/kernel/power/swap.c
@@ -0,0 +1,1619 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/kernel/power/swap.c
+ *
+ * This file provides functions for reading the suspend image from
+ * and writing it to a swap partition.
+ *
+ * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
+ * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
+ * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
+ */
+
+#define pr_fmt(fmt) "PM: " fmt
+
+#include <linux/module.h>
+#include <linux/file.h>
+#include <linux/delay.h>
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/pm.h>
+#include <linux/slab.h>
+#include <linux/lzo.h>
+#include <linux/vmalloc.h>
+#include <linux/cpumask.h>
+#include <linux/atomic.h>
+#include <linux/kthread.h>
+#include <linux/crc32.h>
+#include <linux/ktime.h>
+
+#include "power.h"
+
+#define HIBERNATE_SIG	"S1SUSPEND"
+
+u32 swsusp_hardware_signature;
+
+/*
+ * When reading an {un,}compressed image, we may restore pages in place,
+ * in which case some architectures need these pages cleaning before they
+ * can be executed. We don't know which pages these may be, so clean the lot.
+ */
+static bool clean_pages_on_read;
+static bool clean_pages_on_decompress;
+
+/*
+ *	The swap map is a data structure used for keeping track of each page
+ *	written to a swap partition.  It consists of many swap_map_page
+ *	structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
+ *	These structures are stored on the swap and linked together with the
+ *	help of the .next_swap member.
+ *
+ *	The swap map is created during suspend.  The swap map pages are
+ *	allocated and populated one at a time, so we only need one memory
+ *	page to set up the entire structure.
+ *
+ *	During resume we pick up all swap_map_page structures into a list.
+ */
+
+#define MAP_PAGE_ENTRIES	(PAGE_SIZE / sizeof(sector_t) - 1)
+
+/*
+ * Number of free pages that are not high.
+ */
+static inline unsigned long low_free_pages(void)
+{
+	return nr_free_pages() - nr_free_highpages();
+}
+
+/*
+ * Number of pages required to be kept free while writing the image. Always
+ * half of all available low pages before the writing starts.
+ */
+static inline unsigned long reqd_free_pages(void)
+{
+	return low_free_pages() / 2;
+}
+
+struct swap_map_page {
+	sector_t entries[MAP_PAGE_ENTRIES];
+	sector_t next_swap;
+};
+
+struct swap_map_page_list {
+	struct swap_map_page *map;
+	struct swap_map_page_list *next;
+};
+
+/*
+ *	The swap_map_handle structure is used for handling swap in
+ *	a file-alike way
+ */
+
+struct swap_map_handle {
+	struct swap_map_page *cur;
+	struct swap_map_page_list *maps;
+	sector_t cur_swap;
+	sector_t first_sector;
+	unsigned int k;
+	unsigned long reqd_free_pages;
+	u32 crc32;
+};
+
+struct swsusp_header {
+	char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
+	              sizeof(u32) - sizeof(u32)];
+	u32	hw_sig;
+	u32	crc32;
+	sector_t image;
+	unsigned int flags;	/* Flags to pass to the "boot" kernel */
+	char	orig_sig[10];
+	char	sig[10];
+} __packed;
+
+static struct swsusp_header *swsusp_header;
+
+/*
+ *	The following functions are used for tracing the allocated
+ *	swap pages, so that they can be freed in case of an error.
+ */
+
+struct swsusp_extent {
+	struct rb_node node;
+	unsigned long start;
+	unsigned long end;
+};
+
+static struct rb_root swsusp_extents = RB_ROOT;
+
+static int swsusp_extents_insert(unsigned long swap_offset)
+{
+	struct rb_node **new = &(swsusp_extents.rb_node);
+	struct rb_node *parent = NULL;
+	struct swsusp_extent *ext;
+
+	/* Figure out where to put the new node */
+	while (*new) {
+		ext = rb_entry(*new, struct swsusp_extent, node);
+		parent = *new;
+		if (swap_offset < ext->start) {
+			/* Try to merge */
+			if (swap_offset == ext->start - 1) {
+				ext->start--;
+				return 0;
+			}
+			new = &((*new)->rb_left);
+		} else if (swap_offset > ext->end) {
+			/* Try to merge */
+			if (swap_offset == ext->end + 1) {
+				ext->end++;
+				return 0;
+			}
+			new = &((*new)->rb_right);
+		} else {
+			/* It already is in the tree */
+			return -EINVAL;
+		}
+	}
+	/* Add the new node and rebalance the tree. */
+	ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
+	if (!ext)
+		return -ENOMEM;
+
+	ext->start = swap_offset;
+	ext->end = swap_offset;
+	rb_link_node(&ext->node, parent, new);
+	rb_insert_color(&ext->node, &swsusp_extents);
+	return 0;
+}
+
+/*
+ *	alloc_swapdev_block - allocate a swap page and register that it has
+ *	been allocated, so that it can be freed in case of an error.
+ */
+
+sector_t alloc_swapdev_block(int swap)
+{
+	unsigned long offset;
+
+	offset = swp_offset(get_swap_page_of_type(swap));
+	if (offset) {
+		if (swsusp_extents_insert(offset))
+			swap_free(swp_entry(swap, offset));
+		else
+			return swapdev_block(swap, offset);
+	}
+	return 0;
+}
+
+/*
+ *	free_all_swap_pages - free swap pages allocated for saving image data.
+ *	It also frees the extents used to register which swap entries had been
+ *	allocated.
+ */
+
+void free_all_swap_pages(int swap)
+{
+	struct rb_node *node;
+
+	while ((node = swsusp_extents.rb_node)) {
+		struct swsusp_extent *ext;
+		unsigned long offset;
+
+		ext = rb_entry(node, struct swsusp_extent, node);
+		rb_erase(node, &swsusp_extents);
+		for (offset = ext->start; offset <= ext->end; offset++)
+			swap_free(swp_entry(swap, offset));
+
+		kfree(ext);
+	}
+}
+
+int swsusp_swap_in_use(void)
+{
+	return (swsusp_extents.rb_node != NULL);
+}
+
+/*
+ * General things
+ */
+
+static unsigned short root_swap = 0xffff;
+static struct block_device *hib_resume_bdev;
+
+struct hib_bio_batch {
+	atomic_t		count;
+	wait_queue_head_t	wait;
+	blk_status_t		error;
+	struct blk_plug		plug;
+};
+
+static void hib_init_batch(struct hib_bio_batch *hb)
+{
+	atomic_set(&hb->count, 0);
+	init_waitqueue_head(&hb->wait);
+	hb->error = BLK_STS_OK;
+	blk_start_plug(&hb->plug);
+}
+
+static void hib_finish_batch(struct hib_bio_batch *hb)
+{
+	blk_finish_plug(&hb->plug);
+}
+
+static void hib_end_io(struct bio *bio)
+{
+	struct hib_bio_batch *hb = bio->bi_private;
+	struct page *page = bio_first_page_all(bio);
+
+	if (bio->bi_status) {
+		pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
+			 MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
+			 (unsigned long long)bio->bi_iter.bi_sector);
+	}
+
+	if (bio_data_dir(bio) == WRITE)
+		put_page(page);
+	else if (clean_pages_on_read)
+		flush_icache_range((unsigned long)page_address(page),
+				   (unsigned long)page_address(page) + PAGE_SIZE);
+
+	if (bio->bi_status && !hb->error)
+		hb->error = bio->bi_status;
+	if (atomic_dec_and_test(&hb->count))
+		wake_up(&hb->wait);
+
+	bio_put(bio);
+}
+
+static int hib_submit_io(blk_opf_t opf, pgoff_t page_off, void *addr,
+			 struct hib_bio_batch *hb)
+{
+	struct page *page = virt_to_page(addr);
+	struct bio *bio;
+	int error = 0;
+
+	bio = bio_alloc(hib_resume_bdev, 1, opf, GFP_NOIO | __GFP_HIGH);
+	bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
+
+	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
+		pr_err("Adding page to bio failed at %llu\n",
+		       (unsigned long long)bio->bi_iter.bi_sector);
+		bio_put(bio);
+		return -EFAULT;
+	}
+
+	if (hb) {
+		bio->bi_end_io = hib_end_io;
+		bio->bi_private = hb;
+		atomic_inc(&hb->count);
+		submit_bio(bio);
+	} else {
+		error = submit_bio_wait(bio);
+		bio_put(bio);
+	}
+
+	return error;
+}
+
+static int hib_wait_io(struct hib_bio_batch *hb)
+{
+	/*
+	 * We are relying on the behavior of blk_plug that a thread with
+	 * a plug will flush the plug list before sleeping.
+	 */
+	wait_event(hb->wait, atomic_read(&hb->count) == 0);
+	return blk_status_to_errno(hb->error);
+}
+
+/*
+ * Saving part
+ */
+static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
+{
+	int error;
+
+	hib_submit_io(REQ_OP_READ, swsusp_resume_block, swsusp_header, NULL);
+	if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
+	    !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
+		memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
+		memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
+		swsusp_header->image = handle->first_sector;
+		if (swsusp_hardware_signature) {
+			swsusp_header->hw_sig = swsusp_hardware_signature;
+			flags |= SF_HW_SIG;
+		}
+		swsusp_header->flags = flags;
+		if (flags & SF_CRC32_MODE)
+			swsusp_header->crc32 = handle->crc32;
+		error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
+				      swsusp_resume_block, swsusp_header, NULL);
+	} else {
+		pr_err("Swap header not found!\n");
+		error = -ENODEV;
+	}
+	return error;
+}
+
+/**
+ *	swsusp_swap_check - check if the resume device is a swap device
+ *	and get its index (if so)
+ *
+ *	This is called before saving image
+ */
+static int swsusp_swap_check(void)
+{
+	int res;
+
+	if (swsusp_resume_device)
+		res = swap_type_of(swsusp_resume_device, swsusp_resume_block);
+	else
+		res = find_first_swap(&swsusp_resume_device);
+	if (res < 0)
+		return res;
+	root_swap = res;
+
+	hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
+			BLK_OPEN_WRITE, NULL, NULL);
+	if (IS_ERR(hib_resume_bdev))
+		return PTR_ERR(hib_resume_bdev);
+
+	res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
+	if (res < 0)
+		blkdev_put(hib_resume_bdev, NULL);
+
+	return res;
+}
+
+/**
+ *	write_page - Write one page to given swap location.
+ *	@buf:		Address we're writing.
+ *	@offset:	Offset of the swap page we're writing to.
+ *	@hb:		bio completion batch
+ */
+
+static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
+{
+	void *src;
+	int ret;
+
+	if (!offset)
+		return -ENOSPC;
+
+	if (hb) {
+		src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
+		                              __GFP_NORETRY);
+		if (src) {
+			copy_page(src, buf);
+		} else {
+			ret = hib_wait_io(hb); /* Free pages */
+			if (ret)
+				return ret;
+			src = (void *)__get_free_page(GFP_NOIO |
+			                              __GFP_NOWARN |
+			                              __GFP_NORETRY);
+			if (src) {
+				copy_page(src, buf);
+			} else {
+				WARN_ON_ONCE(1);
+				hb = NULL;	/* Go synchronous */
+				src = buf;
+			}
+		}
+	} else {
+		src = buf;
+	}
+	return hib_submit_io(REQ_OP_WRITE | REQ_SYNC, offset, src, hb);
+}
+
+static void release_swap_writer(struct swap_map_handle *handle)
+{
+	if (handle->cur)
+		free_page((unsigned long)handle->cur);
+	handle->cur = NULL;
+}
+
+static int get_swap_writer(struct swap_map_handle *handle)
+{
+	int ret;
+
+	ret = swsusp_swap_check();
+	if (ret) {
+		if (ret != -ENOSPC)
+			pr_err("Cannot find swap device, try swapon -a\n");
+		return ret;
+	}
+	handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
+	if (!handle->cur) {
+		ret = -ENOMEM;
+		goto err_close;
+	}
+	handle->cur_swap = alloc_swapdev_block(root_swap);
+	if (!handle->cur_swap) {
+		ret = -ENOSPC;
+		goto err_rel;
+	}
+	handle->k = 0;
+	handle->reqd_free_pages = reqd_free_pages();
+	handle->first_sector = handle->cur_swap;
+	return 0;
+err_rel:
+	release_swap_writer(handle);
+err_close:
+	swsusp_close(false);
+	return ret;
+}
+
+static int swap_write_page(struct swap_map_handle *handle, void *buf,
+		struct hib_bio_batch *hb)
+{
+	int error = 0;
+	sector_t offset;
+
+	if (!handle->cur)
+		return -EINVAL;
+	offset = alloc_swapdev_block(root_swap);
+	error = write_page(buf, offset, hb);
+	if (error)
+		return error;
+	handle->cur->entries[handle->k++] = offset;
+	if (handle->k >= MAP_PAGE_ENTRIES) {
+		offset = alloc_swapdev_block(root_swap);
+		if (!offset)
+			return -ENOSPC;
+		handle->cur->next_swap = offset;
+		error = write_page(handle->cur, handle->cur_swap, hb);
+		if (error)
+			goto out;
+		clear_page(handle->cur);
+		handle->cur_swap = offset;
+		handle->k = 0;
+
+		if (hb && low_free_pages() <= handle->reqd_free_pages) {
+			error = hib_wait_io(hb);
+			if (error)
+				goto out;
+			/*
+			 * Recalculate the number of required free pages, to
+			 * make sure we never take more than half.
+			 */
+			handle->reqd_free_pages = reqd_free_pages();
+		}
+	}
+ out:
+	return error;
+}
+
+static int flush_swap_writer(struct swap_map_handle *handle)
+{
+	if (handle->cur && handle->cur_swap)
+		return write_page(handle->cur, handle->cur_swap, NULL);
+	else
+		return -EINVAL;
+}
+
+static int swap_writer_finish(struct swap_map_handle *handle,
+		unsigned int flags, int error)
+{
+	if (!error) {
+		pr_info("S");
+		error = mark_swapfiles(handle, flags);
+		pr_cont("|\n");
+		flush_swap_writer(handle);
+	}
+
+	if (error)
+		free_all_swap_pages(root_swap);
+	release_swap_writer(handle);
+	swsusp_close(false);
+
+	return error;
+}
+
+/* We need to remember how much compressed data we need to read. */
+#define LZO_HEADER	sizeof(size_t)
+
+/* Number of pages/bytes we'll compress at one time. */
+#define LZO_UNC_PAGES	32
+#define LZO_UNC_SIZE	(LZO_UNC_PAGES * PAGE_SIZE)
+
+/* Number of pages/bytes we need for compressed data (worst case). */
+#define LZO_CMP_PAGES	DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
+			             LZO_HEADER, PAGE_SIZE)
+#define LZO_CMP_SIZE	(LZO_CMP_PAGES * PAGE_SIZE)
+
+/* Maximum number of threads for compression/decompression. */
+#define LZO_THREADS	3
+
+/* Minimum/maximum number of pages for read buffering. */
+#define LZO_MIN_RD_PAGES	1024
+#define LZO_MAX_RD_PAGES	8192
+
+
+/**
+ *	save_image - save the suspend image data
+ */
+
+static int save_image(struct swap_map_handle *handle,
+                      struct snapshot_handle *snapshot,
+                      unsigned int nr_to_write)
+{
+	unsigned int m;
+	int ret;
+	int nr_pages;
+	int err2;
+	struct hib_bio_batch hb;
+	ktime_t start;
+	ktime_t stop;
+
+	hib_init_batch(&hb);
+
+	pr_info("Saving image data pages (%u pages)...\n",
+		nr_to_write);
+	m = nr_to_write / 10;
+	if (!m)
+		m = 1;
+	nr_pages = 0;
+	start = ktime_get();
+	while (1) {
+		ret = snapshot_read_next(snapshot);
+		if (ret <= 0)
+			break;
+		ret = swap_write_page(handle, data_of(*snapshot), &hb);
+		if (ret)
+			break;
+		if (!(nr_pages % m))
+			pr_info("Image saving progress: %3d%%\n",
+				nr_pages / m * 10);
+		nr_pages++;
+	}
+	err2 = hib_wait_io(&hb);
+	hib_finish_batch(&hb);
+	stop = ktime_get();
+	if (!ret)
+		ret = err2;
+	if (!ret)
+		pr_info("Image saving done\n");
+	swsusp_show_speed(start, stop, nr_to_write, "Wrote");
+	return ret;
+}
+
+/*
+ * Structure used for CRC32.
+ */
+struct crc_data {
+	struct task_struct *thr;                  /* thread */
+	atomic_t ready;                           /* ready to start flag */
+	atomic_t stop;                            /* ready to stop flag */
+	unsigned run_threads;                     /* nr current threads */
+	wait_queue_head_t go;                     /* start crc update */
+	wait_queue_head_t done;                   /* crc update done */
+	u32 *crc32;                               /* points to handle's crc32 */
+	size_t *unc_len[LZO_THREADS];             /* uncompressed lengths */
+	unsigned char *unc[LZO_THREADS];          /* uncompressed data */
+};
+
+/*
+ * CRC32 update function that runs in its own thread.
+ */
+static int crc32_threadfn(void *data)
+{
+	struct crc_data *d = data;
+	unsigned i;
+
+	while (1) {
+		wait_event(d->go, atomic_read_acquire(&d->ready) ||
+		                  kthread_should_stop());
+		if (kthread_should_stop()) {
+			d->thr = NULL;
+			atomic_set_release(&d->stop, 1);
+			wake_up(&d->done);
+			break;
+		}
+		atomic_set(&d->ready, 0);
+
+		for (i = 0; i < d->run_threads; i++)
+			*d->crc32 = crc32_le(*d->crc32,
+			                     d->unc[i], *d->unc_len[i]);
+		atomic_set_release(&d->stop, 1);
+		wake_up(&d->done);
+	}
+	return 0;
+}
+/*
+ * Structure used for LZO data compression.
+ */
+struct cmp_data {
+	struct task_struct *thr;                  /* thread */
+	atomic_t ready;                           /* ready to start flag */
+	atomic_t stop;                            /* ready to stop flag */
+	int ret;                                  /* return code */
+	wait_queue_head_t go;                     /* start compression */
+	wait_queue_head_t done;                   /* compression done */
+	size_t unc_len;                           /* uncompressed length */
+	size_t cmp_len;                           /* compressed length */
+	unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
+	unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
+	unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
+};
+
+/*
+ * Compression function that runs in its own thread.
+ */
+static int lzo_compress_threadfn(void *data)
+{
+	struct cmp_data *d = data;
+
+	while (1) {
+		wait_event(d->go, atomic_read_acquire(&d->ready) ||
+		                  kthread_should_stop());
+		if (kthread_should_stop()) {
+			d->thr = NULL;
+			d->ret = -1;
+			atomic_set_release(&d->stop, 1);
+			wake_up(&d->done);
+			break;
+		}
+		atomic_set(&d->ready, 0);
+
+		d->ret = lzo1x_1_compress(d->unc, d->unc_len,
+		                          d->cmp + LZO_HEADER, &d->cmp_len,
+		                          d->wrk);
+		atomic_set_release(&d->stop, 1);
+		wake_up(&d->done);
+	}
+	return 0;
+}
+
+/**
+ * save_image_lzo - Save the suspend image data compressed with LZO.
+ * @handle: Swap map handle to use for saving the image.
+ * @snapshot: Image to read data from.
+ * @nr_to_write: Number of pages to save.
+ */
+static int save_image_lzo(struct swap_map_handle *handle,
+                          struct snapshot_handle *snapshot,
+                          unsigned int nr_to_write)
+{
+	unsigned int m;
+	int ret = 0;
+	int nr_pages;
+	int err2;
+	struct hib_bio_batch hb;
+	ktime_t start;
+	ktime_t stop;
+	size_t off;
+	unsigned thr, run_threads, nr_threads;
+	unsigned char *page = NULL;
+	struct cmp_data *data = NULL;
+	struct crc_data *crc = NULL;
+
+	hib_init_batch(&hb);
+
+	/*
+	 * We'll limit the number of threads for compression to limit memory
+	 * footprint.
+	 */
+	nr_threads = num_online_cpus() - 1;
+	nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
+
+	page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
+	if (!page) {
+		pr_err("Failed to allocate LZO page\n");
+		ret = -ENOMEM;
+		goto out_clean;
+	}
+
+	data = vzalloc(array_size(nr_threads, sizeof(*data)));
+	if (!data) {
+		pr_err("Failed to allocate LZO data\n");
+		ret = -ENOMEM;
+		goto out_clean;
+	}
+
+	crc = kzalloc(sizeof(*crc), GFP_KERNEL);
+	if (!crc) {
+		pr_err("Failed to allocate crc\n");
+		ret = -ENOMEM;
+		goto out_clean;
+	}
+
+	/*
+	 * Start the compression threads.
+	 */
+	for (thr = 0; thr < nr_threads; thr++) {
+		init_waitqueue_head(&data[thr].go);
+		init_waitqueue_head(&data[thr].done);
+
+		data[thr].thr = kthread_run(lzo_compress_threadfn,
+		                            &data[thr],
+		                            "image_compress/%u", thr);
+		if (IS_ERR(data[thr].thr)) {
+			data[thr].thr = NULL;
+			pr_err("Cannot start compression threads\n");
+			ret = -ENOMEM;
+			goto out_clean;
+		}
+	}
+
+	/*
+	 * Start the CRC32 thread.
+	 */
+	init_waitqueue_head(&crc->go);
+	init_waitqueue_head(&crc->done);
+
+	handle->crc32 = 0;
+	crc->crc32 = &handle->crc32;
+	for (thr = 0; thr < nr_threads; thr++) {
+		crc->unc[thr] = data[thr].unc;
+		crc->unc_len[thr] = &data[thr].unc_len;
+	}
+
+	crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
+	if (IS_ERR(crc->thr)) {
+		crc->thr = NULL;
+		pr_err("Cannot start CRC32 thread\n");
+		ret = -ENOMEM;
+		goto out_clean;
+	}
+
+	/*
+	 * Adjust the number of required free pages after all allocations have
+	 * been done. We don't want to run out of pages when writing.
+	 */
+	handle->reqd_free_pages = reqd_free_pages();
+
+	pr_info("Using %u thread(s) for compression\n", nr_threads);
+	pr_info("Compressing and saving image data (%u pages)...\n",
+		nr_to_write);
+	m = nr_to_write / 10;
+	if (!m)
+		m = 1;
+	nr_pages = 0;
+	start = ktime_get();
+	for (;;) {
+		for (thr = 0; thr < nr_threads; thr++) {
+			for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
+				ret = snapshot_read_next(snapshot);
+				if (ret < 0)
+					goto out_finish;
+
+				if (!ret)
+					break;
+
+				memcpy(data[thr].unc + off,
+				       data_of(*snapshot), PAGE_SIZE);
+
+				if (!(nr_pages % m))
+					pr_info("Image saving progress: %3d%%\n",
+						nr_pages / m * 10);
+				nr_pages++;
+			}
+			if (!off)
+				break;
+
+			data[thr].unc_len = off;
+
+			atomic_set_release(&data[thr].ready, 1);
+			wake_up(&data[thr].go);
+		}
+
+		if (!thr)
+			break;
+
+		crc->run_threads = thr;
+		atomic_set_release(&crc->ready, 1);
+		wake_up(&crc->go);
+
+		for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
+			wait_event(data[thr].done,
+				atomic_read_acquire(&data[thr].stop));
+			atomic_set(&data[thr].stop, 0);
+
+			ret = data[thr].ret;
+
+			if (ret < 0) {
+				pr_err("LZO compression failed\n");
+				goto out_finish;
+			}
+
+			if (unlikely(!data[thr].cmp_len ||
+			             data[thr].cmp_len >
+			             lzo1x_worst_compress(data[thr].unc_len))) {
+				pr_err("Invalid LZO compressed length\n");
+				ret = -1;
+				goto out_finish;
+			}
+
+			*(size_t *)data[thr].cmp = data[thr].cmp_len;
+
+			/*
+			 * Given we are writing one page at a time to disk, we
+			 * copy that much from the buffer, although the last
+			 * bit will likely be smaller than full page. This is
+			 * OK - we saved the length of the compressed data, so
+			 * any garbage at the end will be discarded when we
+			 * read it.
+			 */
+			for (off = 0;
+			     off < LZO_HEADER + data[thr].cmp_len;
+			     off += PAGE_SIZE) {
+				memcpy(page, data[thr].cmp + off, PAGE_SIZE);
+
+				ret = swap_write_page(handle, page, &hb);
+				if (ret)
+					goto out_finish;
+			}
+		}
+
+		wait_event(crc->done, atomic_read_acquire(&crc->stop));
+		atomic_set(&crc->stop, 0);
+	}
+
+out_finish:
+	err2 = hib_wait_io(&hb);
+	stop = ktime_get();
+	if (!ret)
+		ret = err2;
+	if (!ret)
+		pr_info("Image saving done\n");
+	swsusp_show_speed(start, stop, nr_to_write, "Wrote");
+out_clean:
+	hib_finish_batch(&hb);
+	if (crc) {
+		if (crc->thr)
+			kthread_stop(crc->thr);
+		kfree(crc);
+	}
+	if (data) {
+		for (thr = 0; thr < nr_threads; thr++)
+			if (data[thr].thr)
+				kthread_stop(data[thr].thr);
+		vfree(data);
+	}
+	if (page) free_page((unsigned long)page);
+
+	return ret;
+}
+
+/**
+ *	enough_swap - Make sure we have enough swap to save the image.
+ *
+ *	Returns TRUE or FALSE after checking the total amount of swap
+ *	space available from the resume partition.
+ */
+
+static int enough_swap(unsigned int nr_pages)
+{
+	unsigned int free_swap = count_swap_pages(root_swap, 1);
+	unsigned int required;
+
+	pr_debug("Free swap pages: %u\n", free_swap);
+
+	required = PAGES_FOR_IO + nr_pages;
+	return free_swap > required;
+}
+
+/**
+ *	swsusp_write - Write entire image and metadata.
+ *	@flags: flags to pass to the "boot" kernel in the image header
+ *
+ *	It is important _NOT_ to umount filesystems at this point. We want
+ *	them synced (in case something goes wrong) but we DO not want to mark
+ *	filesystem clean: it is not. (And it does not matter, if we resume
+ *	correctly, we'll mark system clean, anyway.)
+ */
+
+int swsusp_write(unsigned int flags)
+{
+	struct swap_map_handle handle;
+	struct snapshot_handle snapshot;
+	struct swsusp_info *header;
+	unsigned long pages;
+	int error;
+
+	pages = snapshot_get_image_size();
+	error = get_swap_writer(&handle);
+	if (error) {
+		pr_err("Cannot get swap writer\n");
+		return error;
+	}
+	if (flags & SF_NOCOMPRESS_MODE) {
+		if (!enough_swap(pages)) {
+			pr_err("Not enough free swap\n");
+			error = -ENOSPC;
+			goto out_finish;
+		}
+	}
+	memset(&snapshot, 0, sizeof(struct snapshot_handle));
+	error = snapshot_read_next(&snapshot);
+	if (error < (int)PAGE_SIZE) {
+		if (error >= 0)
+			error = -EFAULT;
+
+		goto out_finish;
+	}
+	header = (struct swsusp_info *)data_of(snapshot);
+	error = swap_write_page(&handle, header, NULL);
+	if (!error) {
+		error = (flags & SF_NOCOMPRESS_MODE) ?
+			save_image(&handle, &snapshot, pages - 1) :
+			save_image_lzo(&handle, &snapshot, pages - 1);
+	}
+out_finish:
+	error = swap_writer_finish(&handle, flags, error);
+	return error;
+}
+
+/*
+ *	The following functions allow us to read data using a swap map
+ *	in a file-like way.
+ */
+
+static void release_swap_reader(struct swap_map_handle *handle)
+{
+	struct swap_map_page_list *tmp;
+
+	while (handle->maps) {
+		if (handle->maps->map)
+			free_page((unsigned long)handle->maps->map);
+		tmp = handle->maps;
+		handle->maps = handle->maps->next;
+		kfree(tmp);
+	}
+	handle->cur = NULL;
+}
+
+static int get_swap_reader(struct swap_map_handle *handle,
+		unsigned int *flags_p)
+{
+	int error;
+	struct swap_map_page_list *tmp, *last;
+	sector_t offset;
+
+	*flags_p = swsusp_header->flags;
+
+	if (!swsusp_header->image) /* how can this happen? */
+		return -EINVAL;
+
+	handle->cur = NULL;
+	last = handle->maps = NULL;
+	offset = swsusp_header->image;
+	while (offset) {
+		tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL);
+		if (!tmp) {
+			release_swap_reader(handle);
+			return -ENOMEM;
+		}
+		if (!handle->maps)
+			handle->maps = tmp;
+		if (last)
+			last->next = tmp;
+		last = tmp;
+
+		tmp->map = (struct swap_map_page *)
+			   __get_free_page(GFP_NOIO | __GFP_HIGH);
+		if (!tmp->map) {
+			release_swap_reader(handle);
+			return -ENOMEM;
+		}
+
+		error = hib_submit_io(REQ_OP_READ, offset, tmp->map, NULL);
+		if (error) {
+			release_swap_reader(handle);
+			return error;
+		}
+		offset = tmp->map->next_swap;
+	}
+	handle->k = 0;
+	handle->cur = handle->maps->map;
+	return 0;
+}
+
+static int swap_read_page(struct swap_map_handle *handle, void *buf,
+		struct hib_bio_batch *hb)
+{
+	sector_t offset;
+	int error;
+	struct swap_map_page_list *tmp;
+
+	if (!handle->cur)
+		return -EINVAL;
+	offset = handle->cur->entries[handle->k];
+	if (!offset)
+		return -EFAULT;
+	error = hib_submit_io(REQ_OP_READ, offset, buf, hb);
+	if (error)
+		return error;
+	if (++handle->k >= MAP_PAGE_ENTRIES) {
+		handle->k = 0;
+		free_page((unsigned long)handle->maps->map);
+		tmp = handle->maps;
+		handle->maps = handle->maps->next;
+		kfree(tmp);
+		if (!handle->maps)
+			release_swap_reader(handle);
+		else
+			handle->cur = handle->maps->map;
+	}
+	return error;
+}
+
+static int swap_reader_finish(struct swap_map_handle *handle)
+{
+	release_swap_reader(handle);
+
+	return 0;
+}
+
+/**
+ *	load_image - load the image using the swap map handle
+ *	@handle and the snapshot handle @snapshot
+ *	(assume there are @nr_pages pages to load)
+ */
+
+static int load_image(struct swap_map_handle *handle,
+                      struct snapshot_handle *snapshot,
+                      unsigned int nr_to_read)
+{
+	unsigned int m;
+	int ret = 0;
+	ktime_t start;
+	ktime_t stop;
+	struct hib_bio_batch hb;
+	int err2;
+	unsigned nr_pages;
+
+	hib_init_batch(&hb);
+
+	clean_pages_on_read = true;
+	pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
+	m = nr_to_read / 10;
+	if (!m)
+		m = 1;
+	nr_pages = 0;
+	start = ktime_get();
+	for ( ; ; ) {
+		ret = snapshot_write_next(snapshot);
+		if (ret <= 0)
+			break;
+		ret = swap_read_page(handle, data_of(*snapshot), &hb);
+		if (ret)
+			break;
+		if (snapshot->sync_read)
+			ret = hib_wait_io(&hb);
+		if (ret)
+			break;
+		if (!(nr_pages % m))
+			pr_info("Image loading progress: %3d%%\n",
+				nr_pages / m * 10);
+		nr_pages++;
+	}
+	err2 = hib_wait_io(&hb);
+	hib_finish_batch(&hb);
+	stop = ktime_get();
+	if (!ret)
+		ret = err2;
+	if (!ret) {
+		pr_info("Image loading done\n");
+		snapshot_write_finalize(snapshot);
+		if (!snapshot_image_loaded(snapshot))
+			ret = -ENODATA;
+	}
+	swsusp_show_speed(start, stop, nr_to_read, "Read");
+	return ret;
+}
+
+/*
+ * Structure used for LZO data decompression.
+ */
+struct dec_data {
+	struct task_struct *thr;                  /* thread */
+	atomic_t ready;                           /* ready to start flag */
+	atomic_t stop;                            /* ready to stop flag */
+	int ret;                                  /* return code */
+	wait_queue_head_t go;                     /* start decompression */
+	wait_queue_head_t done;                   /* decompression done */
+	size_t unc_len;                           /* uncompressed length */
+	size_t cmp_len;                           /* compressed length */
+	unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
+	unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
+};
+
+/*
+ * Decompression function that runs in its own thread.
+ */
+static int lzo_decompress_threadfn(void *data)
+{
+	struct dec_data *d = data;
+
+	while (1) {
+		wait_event(d->go, atomic_read_acquire(&d->ready) ||
+		                  kthread_should_stop());
+		if (kthread_should_stop()) {
+			d->thr = NULL;
+			d->ret = -1;
+			atomic_set_release(&d->stop, 1);
+			wake_up(&d->done);
+			break;
+		}
+		atomic_set(&d->ready, 0);
+
+		d->unc_len = LZO_UNC_SIZE;
+		d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
+		                               d->unc, &d->unc_len);
+		if (clean_pages_on_decompress)
+			flush_icache_range((unsigned long)d->unc,
+					   (unsigned long)d->unc + d->unc_len);
+
+		atomic_set_release(&d->stop, 1);
+		wake_up(&d->done);
+	}
+	return 0;
+}
+
+/**
+ * load_image_lzo - Load compressed image data and decompress them with LZO.
+ * @handle: Swap map handle to use for loading data.
+ * @snapshot: Image to copy uncompressed data into.
+ * @nr_to_read: Number of pages to load.
+ */
+static int load_image_lzo(struct swap_map_handle *handle,
+                          struct snapshot_handle *snapshot,
+                          unsigned int nr_to_read)
+{
+	unsigned int m;
+	int ret = 0;
+	int eof = 0;
+	struct hib_bio_batch hb;
+	ktime_t start;
+	ktime_t stop;
+	unsigned nr_pages;
+	size_t off;
+	unsigned i, thr, run_threads, nr_threads;
+	unsigned ring = 0, pg = 0, ring_size = 0,
+	         have = 0, want, need, asked = 0;
+	unsigned long read_pages = 0;
+	unsigned char **page = NULL;
+	struct dec_data *data = NULL;
+	struct crc_data *crc = NULL;
+
+	hib_init_batch(&hb);
+
+	/*
+	 * We'll limit the number of threads for decompression to limit memory
+	 * footprint.
+	 */
+	nr_threads = num_online_cpus() - 1;
+	nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
+
+	page = vmalloc(array_size(LZO_MAX_RD_PAGES, sizeof(*page)));
+	if (!page) {
+		pr_err("Failed to allocate LZO page\n");
+		ret = -ENOMEM;
+		goto out_clean;
+	}
+
+	data = vzalloc(array_size(nr_threads, sizeof(*data)));
+	if (!data) {
+		pr_err("Failed to allocate LZO data\n");
+		ret = -ENOMEM;
+		goto out_clean;
+	}
+
+	crc = kzalloc(sizeof(*crc), GFP_KERNEL);
+	if (!crc) {
+		pr_err("Failed to allocate crc\n");
+		ret = -ENOMEM;
+		goto out_clean;
+	}
+
+	clean_pages_on_decompress = true;
+
+	/*
+	 * Start the decompression threads.
+	 */
+	for (thr = 0; thr < nr_threads; thr++) {
+		init_waitqueue_head(&data[thr].go);
+		init_waitqueue_head(&data[thr].done);
+
+		data[thr].thr = kthread_run(lzo_decompress_threadfn,
+		                            &data[thr],
+		                            "image_decompress/%u", thr);
+		if (IS_ERR(data[thr].thr)) {
+			data[thr].thr = NULL;
+			pr_err("Cannot start decompression threads\n");
+			ret = -ENOMEM;
+			goto out_clean;
+		}
+	}
+
+	/*
+	 * Start the CRC32 thread.
+	 */
+	init_waitqueue_head(&crc->go);
+	init_waitqueue_head(&crc->done);
+
+	handle->crc32 = 0;
+	crc->crc32 = &handle->crc32;
+	for (thr = 0; thr < nr_threads; thr++) {
+		crc->unc[thr] = data[thr].unc;
+		crc->unc_len[thr] = &data[thr].unc_len;
+	}
+
+	crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
+	if (IS_ERR(crc->thr)) {
+		crc->thr = NULL;
+		pr_err("Cannot start CRC32 thread\n");
+		ret = -ENOMEM;
+		goto out_clean;
+	}
+
+	/*
+	 * Set the number of pages for read buffering.
+	 * This is complete guesswork, because we'll only know the real
+	 * picture once prepare_image() is called, which is much later on
+	 * during the image load phase. We'll assume the worst case and
+	 * say that none of the image pages are from high memory.
+	 */
+	if (low_free_pages() > snapshot_get_image_size())
+		read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
+	read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
+
+	for (i = 0; i < read_pages; i++) {
+		page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
+						  GFP_NOIO | __GFP_HIGH :
+						  GFP_NOIO | __GFP_NOWARN |
+						  __GFP_NORETRY);
+
+		if (!page[i]) {
+			if (i < LZO_CMP_PAGES) {
+				ring_size = i;
+				pr_err("Failed to allocate LZO pages\n");
+				ret = -ENOMEM;
+				goto out_clean;
+			} else {
+				break;
+			}
+		}
+	}
+	want = ring_size = i;
+
+	pr_info("Using %u thread(s) for decompression\n", nr_threads);
+	pr_info("Loading and decompressing image data (%u pages)...\n",
+		nr_to_read);
+	m = nr_to_read / 10;
+	if (!m)
+		m = 1;
+	nr_pages = 0;
+	start = ktime_get();
+
+	ret = snapshot_write_next(snapshot);
+	if (ret <= 0)
+		goto out_finish;
+
+	for(;;) {
+		for (i = 0; !eof && i < want; i++) {
+			ret = swap_read_page(handle, page[ring], &hb);
+			if (ret) {
+				/*
+				 * On real read error, finish. On end of data,
+				 * set EOF flag and just exit the read loop.
+				 */
+				if (handle->cur &&
+				    handle->cur->entries[handle->k]) {
+					goto out_finish;
+				} else {
+					eof = 1;
+					break;
+				}
+			}
+			if (++ring >= ring_size)
+				ring = 0;
+		}
+		asked += i;
+		want -= i;
+
+		/*
+		 * We are out of data, wait for some more.
+		 */
+		if (!have) {
+			if (!asked)
+				break;
+
+			ret = hib_wait_io(&hb);
+			if (ret)
+				goto out_finish;
+			have += asked;
+			asked = 0;
+			if (eof)
+				eof = 2;
+		}
+
+		if (crc->run_threads) {
+			wait_event(crc->done, atomic_read_acquire(&crc->stop));
+			atomic_set(&crc->stop, 0);
+			crc->run_threads = 0;
+		}
+
+		for (thr = 0; have && thr < nr_threads; thr++) {
+			data[thr].cmp_len = *(size_t *)page[pg];
+			if (unlikely(!data[thr].cmp_len ||
+			             data[thr].cmp_len >
+			             lzo1x_worst_compress(LZO_UNC_SIZE))) {
+				pr_err("Invalid LZO compressed length\n");
+				ret = -1;
+				goto out_finish;
+			}
+
+			need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
+			                    PAGE_SIZE);
+			if (need > have) {
+				if (eof > 1) {
+					ret = -1;
+					goto out_finish;
+				}
+				break;
+			}
+
+			for (off = 0;
+			     off < LZO_HEADER + data[thr].cmp_len;
+			     off += PAGE_SIZE) {
+				memcpy(data[thr].cmp + off,
+				       page[pg], PAGE_SIZE);
+				have--;
+				want++;
+				if (++pg >= ring_size)
+					pg = 0;
+			}
+
+			atomic_set_release(&data[thr].ready, 1);
+			wake_up(&data[thr].go);
+		}
+
+		/*
+		 * Wait for more data while we are decompressing.
+		 */
+		if (have < LZO_CMP_PAGES && asked) {
+			ret = hib_wait_io(&hb);
+			if (ret)
+				goto out_finish;
+			have += asked;
+			asked = 0;
+			if (eof)
+				eof = 2;
+		}
+
+		for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
+			wait_event(data[thr].done,
+				atomic_read_acquire(&data[thr].stop));
+			atomic_set(&data[thr].stop, 0);
+
+			ret = data[thr].ret;
+
+			if (ret < 0) {
+				pr_err("LZO decompression failed\n");
+				goto out_finish;
+			}
+
+			if (unlikely(!data[thr].unc_len ||
+			             data[thr].unc_len > LZO_UNC_SIZE ||
+			             data[thr].unc_len & (PAGE_SIZE - 1))) {
+				pr_err("Invalid LZO uncompressed length\n");
+				ret = -1;
+				goto out_finish;
+			}
+
+			for (off = 0;
+			     off < data[thr].unc_len; off += PAGE_SIZE) {
+				memcpy(data_of(*snapshot),
+				       data[thr].unc + off, PAGE_SIZE);
+
+				if (!(nr_pages % m))
+					pr_info("Image loading progress: %3d%%\n",
+						nr_pages / m * 10);
+				nr_pages++;
+
+				ret = snapshot_write_next(snapshot);
+				if (ret <= 0) {
+					crc->run_threads = thr + 1;
+					atomic_set_release(&crc->ready, 1);
+					wake_up(&crc->go);
+					goto out_finish;
+				}
+			}
+		}
+
+		crc->run_threads = thr;
+		atomic_set_release(&crc->ready, 1);
+		wake_up(&crc->go);
+	}
+
+out_finish:
+	if (crc->run_threads) {
+		wait_event(crc->done, atomic_read_acquire(&crc->stop));
+		atomic_set(&crc->stop, 0);
+	}
+	stop = ktime_get();
+	if (!ret) {
+		pr_info("Image loading done\n");
+		snapshot_write_finalize(snapshot);
+		if (!snapshot_image_loaded(snapshot))
+			ret = -ENODATA;
+		if (!ret) {
+			if (swsusp_header->flags & SF_CRC32_MODE) {
+				if(handle->crc32 != swsusp_header->crc32) {
+					pr_err("Invalid image CRC32!\n");
+					ret = -ENODATA;
+				}
+			}
+		}
+	}
+	swsusp_show_speed(start, stop, nr_to_read, "Read");
+out_clean:
+	hib_finish_batch(&hb);
+	for (i = 0; i < ring_size; i++)
+		free_page((unsigned long)page[i]);
+	if (crc) {
+		if (crc->thr)
+			kthread_stop(crc->thr);
+		kfree(crc);
+	}
+	if (data) {
+		for (thr = 0; thr < nr_threads; thr++)
+			if (data[thr].thr)
+				kthread_stop(data[thr].thr);
+		vfree(data);
+	}
+	vfree(page);
+
+	return ret;
+}
+
+/**
+ *	swsusp_read - read the hibernation image.
+ *	@flags_p: flags passed by the "frozen" kernel in the image header should
+ *		  be written into this memory location
+ */
+
+int swsusp_read(unsigned int *flags_p)
+{
+	int error;
+	struct swap_map_handle handle;
+	struct snapshot_handle snapshot;
+	struct swsusp_info *header;
+
+	memset(&snapshot, 0, sizeof(struct snapshot_handle));
+	error = snapshot_write_next(&snapshot);
+	if (error < (int)PAGE_SIZE)
+		return error < 0 ? error : -EFAULT;
+	header = (struct swsusp_info *)data_of(snapshot);
+	error = get_swap_reader(&handle, flags_p);
+	if (error)
+		goto end;
+	if (!error)
+		error = swap_read_page(&handle, header, NULL);
+	if (!error) {
+		error = (*flags_p & SF_NOCOMPRESS_MODE) ?
+			load_image(&handle, &snapshot, header->pages - 1) :
+			load_image_lzo(&handle, &snapshot, header->pages - 1);
+	}
+	swap_reader_finish(&handle);
+end:
+	if (!error)
+		pr_debug("Image successfully loaded\n");
+	else
+		pr_debug("Error %d resuming\n", error);
+	return error;
+}
+
+static void *swsusp_holder;
+
+/**
+ * swsusp_check - Check for swsusp signature in the resume device
+ * @exclusive: Open the resume device exclusively.
+ */
+
+int swsusp_check(bool exclusive)
+{
+	void *holder = exclusive ? &swsusp_holder : NULL;
+	int error;
+
+	hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, BLK_OPEN_READ,
+					    holder, NULL);
+	if (!IS_ERR(hib_resume_bdev)) {
+		set_blocksize(hib_resume_bdev, PAGE_SIZE);
+		clear_page(swsusp_header);
+		error = hib_submit_io(REQ_OP_READ, swsusp_resume_block,
+					swsusp_header, NULL);
+		if (error)
+			goto put;
+
+		if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
+			memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
+			/* Reset swap signature now */
+			error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
+						swsusp_resume_block,
+						swsusp_header, NULL);
+		} else {
+			error = -EINVAL;
+		}
+		if (!error && swsusp_header->flags & SF_HW_SIG &&
+		    swsusp_header->hw_sig != swsusp_hardware_signature) {
+			pr_info("Suspend image hardware signature mismatch (%08x now %08x); aborting resume.\n",
+				swsusp_header->hw_sig, swsusp_hardware_signature);
+			error = -EINVAL;
+		}
+
+put:
+		if (error)
+			blkdev_put(hib_resume_bdev, holder);
+		else
+			pr_debug("Image signature found, resuming\n");
+	} else {
+		error = PTR_ERR(hib_resume_bdev);
+	}
+
+	if (error)
+		pr_debug("Image not found (code %d)\n", error);
+
+	return error;
+}
+
+/**
+ * swsusp_close - close swap device.
+ * @exclusive: Close the resume device which is exclusively opened.
+ */
+
+void swsusp_close(bool exclusive)
+{
+	if (IS_ERR(hib_resume_bdev)) {
+		pr_debug("Image device not initialised\n");
+		return;
+	}
+
+	blkdev_put(hib_resume_bdev, exclusive ? &swsusp_holder : NULL);
+}
+
+/**
+ *      swsusp_unmark - Unmark swsusp signature in the resume device
+ */
+
+#ifdef CONFIG_SUSPEND
+int swsusp_unmark(void)
+{
+	int error;
+
+	hib_submit_io(REQ_OP_READ, swsusp_resume_block,
+			swsusp_header, NULL);
+	if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
+		memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
+		error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
+					swsusp_resume_block,
+					swsusp_header, NULL);
+	} else {
+		pr_err("Cannot find swsusp signature!\n");
+		error = -ENODEV;
+	}
+
+	/*
+	 * We just returned from suspend, we don't need the image any more.
+	 */
+	free_all_swap_pages(root_swap);
+
+	return error;
+}
+#endif
+
+static int __init swsusp_header_init(void)
+{
+	swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
+	if (!swsusp_header)
+		panic("Could not allocate memory for swsusp_header\n");
+	return 0;
+}
+
+core_initcall(swsusp_header_init);
diff --git a/kernel/power/user.c b/kernel/power/user.c
new file mode 100644
index 000000000..3a4e70366
--- /dev/null
+++ b/kernel/power/user.c
@@ -0,0 +1,466 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/kernel/power/user.c
+ *
+ * This file provides the user space interface for software suspend/resume.
+ *
+ * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
+ */
+
+#include <linux/suspend.h>
+#include <linux/reboot.h>
+#include <linux/string.h>
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/pm.h>
+#include <linux/fs.h>
+#include <linux/compat.h>
+#include <linux/console.h>
+#include <linux/cpu.h>
+#include <linux/freezer.h>
+
+#include <linux/uaccess.h>
+
+#include "power.h"
+
+static bool need_wait;
+
+static struct snapshot_data {
+	struct snapshot_handle handle;
+	int swap;
+	int mode;
+	bool frozen;
+	bool ready;
+	bool platform_support;
+	bool free_bitmaps;
+	dev_t dev;
+} snapshot_state;
+
+int is_hibernate_resume_dev(dev_t dev)
+{
+	return hibernation_available() && snapshot_state.dev == dev;
+}
+
+static int snapshot_open(struct inode *inode, struct file *filp)
+{
+	struct snapshot_data *data;
+	unsigned int sleep_flags;
+	int error;
+
+	if (!hibernation_available())
+		return -EPERM;
+
+	sleep_flags = lock_system_sleep();
+
+	if (!hibernate_acquire()) {
+		error = -EBUSY;
+		goto Unlock;
+	}
+
+	if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
+		hibernate_release();
+		error = -ENOSYS;
+		goto Unlock;
+	}
+	nonseekable_open(inode, filp);
+	data = &snapshot_state;
+	filp->private_data = data;
+	memset(&data->handle, 0, sizeof(struct snapshot_handle));
+	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
+		/* Hibernating.  The image device should be accessible. */
+		data->swap = swap_type_of(swsusp_resume_device, 0);
+		data->mode = O_RDONLY;
+		data->free_bitmaps = false;
+		error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
+	} else {
+		/*
+		 * Resuming.  We may need to wait for the image device to
+		 * appear.
+		 */
+		need_wait = true;
+
+		data->swap = -1;
+		data->mode = O_WRONLY;
+		error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
+		if (!error) {
+			error = create_basic_memory_bitmaps();
+			data->free_bitmaps = !error;
+		}
+	}
+	if (error)
+		hibernate_release();
+
+	data->frozen = false;
+	data->ready = false;
+	data->platform_support = false;
+	data->dev = 0;
+
+ Unlock:
+	unlock_system_sleep(sleep_flags);
+
+	return error;
+}
+
+static int snapshot_release(struct inode *inode, struct file *filp)
+{
+	struct snapshot_data *data;
+	unsigned int sleep_flags;
+
+	sleep_flags = lock_system_sleep();
+
+	swsusp_free();
+	data = filp->private_data;
+	data->dev = 0;
+	free_all_swap_pages(data->swap);
+	if (data->frozen) {
+		pm_restore_gfp_mask();
+		free_basic_memory_bitmaps();
+		thaw_processes();
+	} else if (data->free_bitmaps) {
+		free_basic_memory_bitmaps();
+	}
+	pm_notifier_call_chain(data->mode == O_RDONLY ?
+			PM_POST_HIBERNATION : PM_POST_RESTORE);
+	hibernate_release();
+
+	unlock_system_sleep(sleep_flags);
+
+	return 0;
+}
+
+static ssize_t snapshot_read(struct file *filp, char __user *buf,
+                             size_t count, loff_t *offp)
+{
+	loff_t pg_offp = *offp & ~PAGE_MASK;
+	struct snapshot_data *data;
+	unsigned int sleep_flags;
+	ssize_t res;
+
+	sleep_flags = lock_system_sleep();
+
+	data = filp->private_data;
+	if (!data->ready) {
+		res = -ENODATA;
+		goto Unlock;
+	}
+	if (!pg_offp) { /* on page boundary? */
+		res = snapshot_read_next(&data->handle);
+		if (res <= 0)
+			goto Unlock;
+	} else {
+		res = PAGE_SIZE - pg_offp;
+	}
+
+	res = simple_read_from_buffer(buf, count, &pg_offp,
+			data_of(data->handle), res);
+	if (res > 0)
+		*offp += res;
+
+ Unlock:
+	unlock_system_sleep(sleep_flags);
+
+	return res;
+}
+
+static ssize_t snapshot_write(struct file *filp, const char __user *buf,
+                              size_t count, loff_t *offp)
+{
+	loff_t pg_offp = *offp & ~PAGE_MASK;
+	struct snapshot_data *data;
+	unsigned long sleep_flags;
+	ssize_t res;
+
+	if (need_wait) {
+		wait_for_device_probe();
+		need_wait = false;
+	}
+
+	sleep_flags = lock_system_sleep();
+
+	data = filp->private_data;
+
+	if (!pg_offp) {
+		res = snapshot_write_next(&data->handle);
+		if (res <= 0)
+			goto unlock;
+	} else {
+		res = PAGE_SIZE;
+	}
+
+	if (!data_of(data->handle)) {
+		res = -EINVAL;
+		goto unlock;
+	}
+
+	res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
+			buf, count);
+	if (res > 0)
+		*offp += res;
+unlock:
+	unlock_system_sleep(sleep_flags);
+
+	return res;
+}
+
+struct compat_resume_swap_area {
+	compat_loff_t offset;
+	u32 dev;
+} __packed;
+
+static int snapshot_set_swap_area(struct snapshot_data *data,
+		void __user *argp)
+{
+	sector_t offset;
+	dev_t swdev;
+
+	if (swsusp_swap_in_use())
+		return -EPERM;
+
+	if (in_compat_syscall()) {
+		struct compat_resume_swap_area swap_area;
+
+		if (copy_from_user(&swap_area, argp, sizeof(swap_area)))
+			return -EFAULT;
+		swdev = new_decode_dev(swap_area.dev);
+		offset = swap_area.offset;
+	} else {
+		struct resume_swap_area swap_area;
+
+		if (copy_from_user(&swap_area, argp, sizeof(swap_area)))
+			return -EFAULT;
+		swdev = new_decode_dev(swap_area.dev);
+		offset = swap_area.offset;
+	}
+
+	/*
+	 * User space encodes device types as two-byte values,
+	 * so we need to recode them
+	 */
+	data->swap = swap_type_of(swdev, offset);
+	if (data->swap < 0)
+		return swdev ? -ENODEV : -EINVAL;
+	data->dev = swdev;
+	return 0;
+}
+
+static long snapshot_ioctl(struct file *filp, unsigned int cmd,
+							unsigned long arg)
+{
+	int error = 0;
+	struct snapshot_data *data;
+	loff_t size;
+	sector_t offset;
+
+	if (need_wait) {
+		wait_for_device_probe();
+		need_wait = false;
+	}
+
+	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
+		return -ENOTTY;
+	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
+		return -ENOTTY;
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (!mutex_trylock(&system_transition_mutex))
+		return -EBUSY;
+
+	lock_device_hotplug();
+	data = filp->private_data;
+
+	switch (cmd) {
+
+	case SNAPSHOT_FREEZE:
+		if (data->frozen)
+			break;
+
+		ksys_sync_helper();
+
+		error = freeze_processes();
+		if (error)
+			break;
+
+		error = create_basic_memory_bitmaps();
+		if (error)
+			thaw_processes();
+		else
+			data->frozen = true;
+
+		break;
+
+	case SNAPSHOT_UNFREEZE:
+		if (!data->frozen || data->ready)
+			break;
+		pm_restore_gfp_mask();
+		free_basic_memory_bitmaps();
+		data->free_bitmaps = false;
+		thaw_processes();
+		data->frozen = false;
+		break;
+
+	case SNAPSHOT_CREATE_IMAGE:
+		if (data->mode != O_RDONLY || !data->frozen  || data->ready) {
+			error = -EPERM;
+			break;
+		}
+		pm_restore_gfp_mask();
+		error = hibernation_snapshot(data->platform_support);
+		if (!error) {
+			error = put_user(in_suspend, (int __user *)arg);
+			data->ready = !freezer_test_done && !error;
+			freezer_test_done = false;
+		}
+		break;
+
+	case SNAPSHOT_ATOMIC_RESTORE:
+		snapshot_write_finalize(&data->handle);
+		if (data->mode != O_WRONLY || !data->frozen ||
+		    !snapshot_image_loaded(&data->handle)) {
+			error = -EPERM;
+			break;
+		}
+		error = hibernation_restore(data->platform_support);
+		break;
+
+	case SNAPSHOT_FREE:
+		swsusp_free();
+		memset(&data->handle, 0, sizeof(struct snapshot_handle));
+		data->ready = false;
+		/*
+		 * It is necessary to thaw kernel threads here, because
+		 * SNAPSHOT_CREATE_IMAGE may be invoked directly after
+		 * SNAPSHOT_FREE.  In that case, if kernel threads were not
+		 * thawed, the preallocation of memory carried out by
+		 * hibernation_snapshot() might run into problems (i.e. it
+		 * might fail or even deadlock).
+		 */
+		thaw_kernel_threads();
+		break;
+
+	case SNAPSHOT_PREF_IMAGE_SIZE:
+		image_size = arg;
+		break;
+
+	case SNAPSHOT_GET_IMAGE_SIZE:
+		if (!data->ready) {
+			error = -ENODATA;
+			break;
+		}
+		size = snapshot_get_image_size();
+		size <<= PAGE_SHIFT;
+		error = put_user(size, (loff_t __user *)arg);
+		break;
+
+	case SNAPSHOT_AVAIL_SWAP_SIZE:
+		size = count_swap_pages(data->swap, 1);
+		size <<= PAGE_SHIFT;
+		error = put_user(size, (loff_t __user *)arg);
+		break;
+
+	case SNAPSHOT_ALLOC_SWAP_PAGE:
+		if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
+			error = -ENODEV;
+			break;
+		}
+		offset = alloc_swapdev_block(data->swap);
+		if (offset) {
+			offset <<= PAGE_SHIFT;
+			error = put_user(offset, (loff_t __user *)arg);
+		} else {
+			error = -ENOSPC;
+		}
+		break;
+
+	case SNAPSHOT_FREE_SWAP_PAGES:
+		if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
+			error = -ENODEV;
+			break;
+		}
+		free_all_swap_pages(data->swap);
+		break;
+
+	case SNAPSHOT_S2RAM:
+		if (!data->frozen) {
+			error = -EPERM;
+			break;
+		}
+		/*
+		 * Tasks are frozen and the notifiers have been called with
+		 * PM_HIBERNATION_PREPARE
+		 */
+		error = suspend_devices_and_enter(PM_SUSPEND_MEM);
+		data->ready = false;
+		break;
+
+	case SNAPSHOT_PLATFORM_SUPPORT:
+		data->platform_support = !!arg;
+		break;
+
+	case SNAPSHOT_POWER_OFF:
+		if (data->platform_support)
+			error = hibernation_platform_enter();
+		break;
+
+	case SNAPSHOT_SET_SWAP_AREA:
+		error = snapshot_set_swap_area(data, (void __user *)arg);
+		break;
+
+	default:
+		error = -ENOTTY;
+
+	}
+
+	unlock_device_hotplug();
+	mutex_unlock(&system_transition_mutex);
+
+	return error;
+}
+
+#ifdef CONFIG_COMPAT
+static long
+snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t));
+
+	switch (cmd) {
+	case SNAPSHOT_GET_IMAGE_SIZE:
+	case SNAPSHOT_AVAIL_SWAP_SIZE:
+	case SNAPSHOT_ALLOC_SWAP_PAGE:
+	case SNAPSHOT_CREATE_IMAGE:
+	case SNAPSHOT_SET_SWAP_AREA:
+		return snapshot_ioctl(file, cmd,
+				      (unsigned long) compat_ptr(arg));
+	default:
+		return snapshot_ioctl(file, cmd, arg);
+	}
+}
+#endif /* CONFIG_COMPAT */
+
+static const struct file_operations snapshot_fops = {
+	.open = snapshot_open,
+	.release = snapshot_release,
+	.read = snapshot_read,
+	.write = snapshot_write,
+	.llseek = no_llseek,
+	.unlocked_ioctl = snapshot_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = snapshot_compat_ioctl,
+#endif
+};
+
+static struct miscdevice snapshot_device = {
+	.minor = SNAPSHOT_MINOR,
+	.name = "snapshot",
+	.fops = &snapshot_fops,
+};
+
+static int __init snapshot_device_init(void)
+{
+	return misc_register(&snapshot_device);
+};
+
+device_initcall(snapshot_device_init);
diff --git a/kernel/power/wakelock.c b/kernel/power/wakelock.c
new file mode 100644
index 000000000..52571dcad
--- /dev/null
+++ b/kernel/power/wakelock.c
@@ -0,0 +1,285 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * kernel/power/wakelock.c
+ *
+ * User space wakeup sources support.
+ *
+ * Copyright (C) 2012 Rafael J. Wysocki <rjw@sisk.pl>
+ *
+ * This code is based on the analogous interface allowing user space to
+ * manipulate wakelocks on Android.
+ */
+
+#include <linux/capability.h>
+#include <linux/ctype.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/hrtimer.h>
+#include <linux/list.h>
+#include <linux/rbtree.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+#include "power.h"
+
+static DEFINE_MUTEX(wakelocks_lock);
+
+struct wakelock {
+	char			*name;
+	struct rb_node		node;
+	struct wakeup_source	*ws;
+#ifdef CONFIG_PM_WAKELOCKS_GC
+	struct list_head	lru;
+#endif
+};
+
+static struct rb_root wakelocks_tree = RB_ROOT;
+
+ssize_t pm_show_wakelocks(char *buf, bool show_active)
+{
+	struct rb_node *node;
+	struct wakelock *wl;
+	int len = 0;
+
+	mutex_lock(&wakelocks_lock);
+
+	for (node = rb_first(&wakelocks_tree); node; node = rb_next(node)) {
+		wl = rb_entry(node, struct wakelock, node);
+		if (wl->ws->active == show_active)
+			len += sysfs_emit_at(buf, len, "%s ", wl->name);
+	}
+
+	len += sysfs_emit_at(buf, len, "\n");
+
+	mutex_unlock(&wakelocks_lock);
+	return len;
+}
+
+#if CONFIG_PM_WAKELOCKS_LIMIT > 0
+static unsigned int number_of_wakelocks;
+
+static inline bool wakelocks_limit_exceeded(void)
+{
+	return number_of_wakelocks > CONFIG_PM_WAKELOCKS_LIMIT;
+}
+
+static inline void increment_wakelocks_number(void)
+{
+	number_of_wakelocks++;
+}
+
+static inline void decrement_wakelocks_number(void)
+{
+	number_of_wakelocks--;
+}
+#else /* CONFIG_PM_WAKELOCKS_LIMIT = 0 */
+static inline bool wakelocks_limit_exceeded(void) { return false; }
+static inline void increment_wakelocks_number(void) {}
+static inline void decrement_wakelocks_number(void) {}
+#endif /* CONFIG_PM_WAKELOCKS_LIMIT */
+
+#ifdef CONFIG_PM_WAKELOCKS_GC
+#define WL_GC_COUNT_MAX	100
+#define WL_GC_TIME_SEC	300
+
+static void __wakelocks_gc(struct work_struct *work);
+static LIST_HEAD(wakelocks_lru_list);
+static DECLARE_WORK(wakelock_work, __wakelocks_gc);
+static unsigned int wakelocks_gc_count;
+
+static inline void wakelocks_lru_add(struct wakelock *wl)
+{
+	list_add(&wl->lru, &wakelocks_lru_list);
+}
+
+static inline void wakelocks_lru_most_recent(struct wakelock *wl)
+{
+	list_move(&wl->lru, &wakelocks_lru_list);
+}
+
+static void __wakelocks_gc(struct work_struct *work)
+{
+	struct wakelock *wl, *aux;
+	ktime_t now;
+
+	mutex_lock(&wakelocks_lock);
+
+	now = ktime_get();
+	list_for_each_entry_safe_reverse(wl, aux, &wakelocks_lru_list, lru) {
+		u64 idle_time_ns;
+		bool active;
+
+		spin_lock_irq(&wl->ws->lock);
+		idle_time_ns = ktime_to_ns(ktime_sub(now, wl->ws->last_time));
+		active = wl->ws->active;
+		spin_unlock_irq(&wl->ws->lock);
+
+		if (idle_time_ns < ((u64)WL_GC_TIME_SEC * NSEC_PER_SEC))
+			break;
+
+		if (!active) {
+			wakeup_source_unregister(wl->ws);
+			rb_erase(&wl->node, &wakelocks_tree);
+			list_del(&wl->lru);
+			kfree(wl->name);
+			kfree(wl);
+			decrement_wakelocks_number();
+		}
+	}
+	wakelocks_gc_count = 0;
+
+	mutex_unlock(&wakelocks_lock);
+}
+
+static void wakelocks_gc(void)
+{
+	if (++wakelocks_gc_count <= WL_GC_COUNT_MAX)
+		return;
+
+	schedule_work(&wakelock_work);
+}
+#else /* !CONFIG_PM_WAKELOCKS_GC */
+static inline void wakelocks_lru_add(struct wakelock *wl) {}
+static inline void wakelocks_lru_most_recent(struct wakelock *wl) {}
+static inline void wakelocks_gc(void) {}
+#endif /* !CONFIG_PM_WAKELOCKS_GC */
+
+static struct wakelock *wakelock_lookup_add(const char *name, size_t len,
+					    bool add_if_not_found)
+{
+	struct rb_node **node = &wakelocks_tree.rb_node;
+	struct rb_node *parent = *node;
+	struct wakelock *wl;
+
+	while (*node) {
+		int diff;
+
+		parent = *node;
+		wl = rb_entry(*node, struct wakelock, node);
+		diff = strncmp(name, wl->name, len);
+		if (diff == 0) {
+			if (wl->name[len])
+				diff = -1;
+			else
+				return wl;
+		}
+		if (diff < 0)
+			node = &(*node)->rb_left;
+		else
+			node = &(*node)->rb_right;
+	}
+	if (!add_if_not_found)
+		return ERR_PTR(-EINVAL);
+
+	if (wakelocks_limit_exceeded())
+		return ERR_PTR(-ENOSPC);
+
+	/* Not found, we have to add a new one. */
+	wl = kzalloc(sizeof(*wl), GFP_KERNEL);
+	if (!wl)
+		return ERR_PTR(-ENOMEM);
+
+	wl->name = kstrndup(name, len, GFP_KERNEL);
+	if (!wl->name) {
+		kfree(wl);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	wl->ws = wakeup_source_register(NULL, wl->name);
+	if (!wl->ws) {
+		kfree(wl->name);
+		kfree(wl);
+		return ERR_PTR(-ENOMEM);
+	}
+	wl->ws->last_time = ktime_get();
+
+	rb_link_node(&wl->node, parent, node);
+	rb_insert_color(&wl->node, &wakelocks_tree);
+	wakelocks_lru_add(wl);
+	increment_wakelocks_number();
+	return wl;
+}
+
+int pm_wake_lock(const char *buf)
+{
+	const char *str = buf;
+	struct wakelock *wl;
+	u64 timeout_ns = 0;
+	size_t len;
+	int ret = 0;
+
+	if (!capable(CAP_BLOCK_SUSPEND))
+		return -EPERM;
+
+	while (*str && !isspace(*str))
+		str++;
+
+	len = str - buf;
+	if (!len)
+		return -EINVAL;
+
+	if (*str && *str != '\n') {
+		/* Find out if there's a valid timeout string appended. */
+		ret = kstrtou64(skip_spaces(str), 10, &timeout_ns);
+		if (ret)
+			return -EINVAL;
+	}
+
+	mutex_lock(&wakelocks_lock);
+
+	wl = wakelock_lookup_add(buf, len, true);
+	if (IS_ERR(wl)) {
+		ret = PTR_ERR(wl);
+		goto out;
+	}
+	if (timeout_ns) {
+		u64 timeout_ms = timeout_ns + NSEC_PER_MSEC - 1;
+
+		do_div(timeout_ms, NSEC_PER_MSEC);
+		__pm_wakeup_event(wl->ws, timeout_ms);
+	} else {
+		__pm_stay_awake(wl->ws);
+	}
+
+	wakelocks_lru_most_recent(wl);
+
+ out:
+	mutex_unlock(&wakelocks_lock);
+	return ret;
+}
+
+int pm_wake_unlock(const char *buf)
+{
+	struct wakelock *wl;
+	size_t len;
+	int ret = 0;
+
+	if (!capable(CAP_BLOCK_SUSPEND))
+		return -EPERM;
+
+	len = strlen(buf);
+	if (!len)
+		return -EINVAL;
+
+	if (buf[len-1] == '\n')
+		len--;
+
+	if (!len)
+		return -EINVAL;
+
+	mutex_lock(&wakelocks_lock);
+
+	wl = wakelock_lookup_add(buf, len, false);
+	if (IS_ERR(wl)) {
+		ret = PTR_ERR(wl);
+		goto out;
+	}
+	__pm_relax(wl->ws);
+
+	wakelocks_lru_most_recent(wl);
+	wakelocks_gc();
+
+ out:
+	mutex_unlock(&wakelocks_lock);
+	return ret;
+}