v4.19.13 snapshot.
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
new file mode 100644
index 0000000..754d59f
--- /dev/null
+++ b/drivers/acpi/sleep.c
@@ -0,0 +1,1297 @@
+/*
+ * sleep.c - ACPI sleep support.
+ *
+ * Copyright (c) 2005 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
+ * Copyright (c) 2004 David Shaohua Li <shaohua.li@intel.com>
+ * Copyright (c) 2000-2003 Patrick Mochel
+ * Copyright (c) 2003 Open Source Development Lab
+ *
+ * This file is released under the GPLv2.
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/dmi.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/suspend.h>
+#include <linux/reboot.h>
+#include <linux/acpi.h>
+#include <linux/module.h>
+#include <linux/syscore_ops.h>
+#include <asm/io.h>
+#include <trace/events/power.h>
+
+#include "internal.h"
+#include "sleep.h"
+
+/*
+ * Some HW-full platforms do not have _S5, so they may need
+ * to leverage efi power off for a shutdown.
+ */
+bool acpi_no_s5;
+static u8 sleep_states[ACPI_S_STATE_COUNT];
+
+static void acpi_sleep_tts_switch(u32 acpi_state)
+{
+	acpi_status status;
+
+	status = acpi_execute_simple_method(NULL, "\\_TTS", acpi_state);
+	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+		/*
+		 * OS can't evaluate the _TTS object correctly. Some warning
+		 * message will be printed. But it won't break anything.
+		 */
+		printk(KERN_NOTICE "Failure in evaluating _TTS object\n");
+	}
+}
+
+static int tts_notify_reboot(struct notifier_block *this,
+			unsigned long code, void *x)
+{
+	acpi_sleep_tts_switch(ACPI_STATE_S5);
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block tts_notifier = {
+	.notifier_call	= tts_notify_reboot,
+	.next		= NULL,
+	.priority	= 0,
+};
+
+static int acpi_sleep_prepare(u32 acpi_state)
+{
+#ifdef CONFIG_ACPI_SLEEP
+	/* do we have a wakeup address for S2 and S3? */
+	if (acpi_state == ACPI_STATE_S3) {
+		if (!acpi_wakeup_address)
+			return -EFAULT;
+		acpi_set_waking_vector(acpi_wakeup_address);
+
+	}
+	ACPI_FLUSH_CPU_CACHE();
+#endif
+	printk(KERN_INFO PREFIX "Preparing to enter system sleep state S%d\n",
+		acpi_state);
+	acpi_enable_wakeup_devices(acpi_state);
+	acpi_enter_sleep_state_prep(acpi_state);
+	return 0;
+}
+
+static bool acpi_sleep_state_supported(u8 sleep_state)
+{
+	acpi_status status;
+	u8 type_a, type_b;
+
+	status = acpi_get_sleep_type_data(sleep_state, &type_a, &type_b);
+	return ACPI_SUCCESS(status) && (!acpi_gbl_reduced_hardware
+		|| (acpi_gbl_FADT.sleep_control.address
+			&& acpi_gbl_FADT.sleep_status.address));
+}
+
+#ifdef CONFIG_ACPI_SLEEP
+static u32 acpi_target_sleep_state = ACPI_STATE_S0;
+
+u32 acpi_target_system_state(void)
+{
+	return acpi_target_sleep_state;
+}
+EXPORT_SYMBOL_GPL(acpi_target_system_state);
+
+static bool pwr_btn_event_pending;
+
+/*
+ * The ACPI specification wants us to save NVS memory regions during hibernation
+ * and to restore them during the subsequent resume.  Windows does that also for
+ * suspend to RAM.  However, it is known that this mechanism does not work on
+ * all machines, so we allow the user to disable it with the help of the
+ * 'acpi_sleep=nonvs' kernel command line option.
+ */
+static bool nvs_nosave;
+
+void __init acpi_nvs_nosave(void)
+{
+	nvs_nosave = true;
+}
+
+/*
+ * The ACPI specification wants us to save NVS memory regions during hibernation
+ * but says nothing about saving NVS during S3.  Not all versions of Windows
+ * save NVS on S3 suspend either, and it is clear that not all systems need
+ * NVS to be saved at S3 time.  To improve suspend/resume time, allow the
+ * user to disable saving NVS on S3 if their system does not require it, but
+ * continue to save/restore NVS for S4 as specified.
+ */
+static bool nvs_nosave_s3;
+
+void __init acpi_nvs_nosave_s3(void)
+{
+	nvs_nosave_s3 = true;
+}
+
+static int __init init_nvs_save_s3(const struct dmi_system_id *d)
+{
+	nvs_nosave_s3 = false;
+	return 0;
+}
+
+/*
+ * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
+ * user to request that behavior by using the 'acpi_old_suspend_ordering'
+ * kernel command line option that causes the following variable to be set.
+ */
+static bool old_suspend_ordering;
+
+void __init acpi_old_suspend_ordering(void)
+{
+	old_suspend_ordering = true;
+}
+
+static int __init init_old_suspend_ordering(const struct dmi_system_id *d)
+{
+	acpi_old_suspend_ordering();
+	return 0;
+}
+
+static int __init init_nvs_nosave(const struct dmi_system_id *d)
+{
+	acpi_nvs_nosave();
+	return 0;
+}
+
+static bool acpi_sleep_no_lps0;
+
+static int __init init_no_lps0(const struct dmi_system_id *d)
+{
+	acpi_sleep_no_lps0 = true;
+	return 0;
+}
+
+static const struct dmi_system_id acpisleep_dmi_table[] __initconst = {
+	{
+	.callback = init_old_suspend_ordering,
+	.ident = "Abit KN9 (nForce4 variant)",
+	.matches = {
+		DMI_MATCH(DMI_BOARD_VENDOR, "http://www.abit.com.tw/"),
+		DMI_MATCH(DMI_BOARD_NAME, "KN9 Series(NF-CK804)"),
+		},
+	},
+	{
+	.callback = init_old_suspend_ordering,
+	.ident = "HP xw4600 Workstation",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "HP xw4600 Workstation"),
+		},
+	},
+	{
+	.callback = init_old_suspend_ordering,
+	.ident = "Asus Pundit P1-AH2 (M2N8L motherboard)",
+	.matches = {
+		DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTek Computer INC."),
+		DMI_MATCH(DMI_BOARD_NAME, "M2N8L"),
+		},
+	},
+	{
+	.callback = init_old_suspend_ordering,
+	.ident = "Panasonic CF51-2L",
+	.matches = {
+		DMI_MATCH(DMI_BOARD_VENDOR,
+				"Matsushita Electric Industrial Co.,Ltd."),
+		DMI_MATCH(DMI_BOARD_NAME, "CF51-2L"),
+		},
+	},
+	{
+	.callback = init_nvs_nosave,
+	.ident = "Sony Vaio VGN-FW41E_H",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "VGN-FW41E_H"),
+		},
+	},
+	{
+	.callback = init_nvs_nosave,
+	.ident = "Sony Vaio VGN-FW21E",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "VGN-FW21E"),
+		},
+	},
+	{
+	.callback = init_nvs_nosave,
+	.ident = "Sony Vaio VGN-FW21M",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "VGN-FW21M"),
+		},
+	},
+	{
+	.callback = init_nvs_nosave,
+	.ident = "Sony Vaio VPCEB17FX",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "VPCEB17FX"),
+		},
+	},
+	{
+	.callback = init_nvs_nosave,
+	.ident = "Sony Vaio VGN-SR11M",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "VGN-SR11M"),
+		},
+	},
+	{
+	.callback = init_nvs_nosave,
+	.ident = "Everex StepNote Series",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Everex Systems, Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "Everex StepNote Series"),
+		},
+	},
+	{
+	.callback = init_nvs_nosave,
+	.ident = "Sony Vaio VPCEB1Z1E",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "VPCEB1Z1E"),
+		},
+	},
+	{
+	.callback = init_nvs_nosave,
+	.ident = "Sony Vaio VGN-NW130D",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "VGN-NW130D"),
+		},
+	},
+	{
+	.callback = init_nvs_nosave,
+	.ident = "Sony Vaio VPCCW29FX",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "VPCCW29FX"),
+		},
+	},
+	{
+	.callback = init_nvs_nosave,
+	.ident = "Averatec AV1020-ED2",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "AVERATEC"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "1000 Series"),
+		},
+	},
+	{
+	.callback = init_old_suspend_ordering,
+	.ident = "Asus A8N-SLI DELUXE",
+	.matches = {
+		DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
+		DMI_MATCH(DMI_BOARD_NAME, "A8N-SLI DELUXE"),
+		},
+	},
+	{
+	.callback = init_old_suspend_ordering,
+	.ident = "Asus A8N-SLI Premium",
+	.matches = {
+		DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
+		DMI_MATCH(DMI_BOARD_NAME, "A8N-SLI Premium"),
+		},
+	},
+	{
+	.callback = init_nvs_nosave,
+	.ident = "Sony Vaio VGN-SR26GN_P",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "VGN-SR26GN_P"),
+		},
+	},
+	{
+	.callback = init_nvs_nosave,
+	.ident = "Sony Vaio VPCEB1S1E",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "VPCEB1S1E"),
+		},
+	},
+	{
+	.callback = init_nvs_nosave,
+	.ident = "Sony Vaio VGN-FW520F",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "VGN-FW520F"),
+		},
+	},
+	{
+	.callback = init_nvs_nosave,
+	.ident = "Asus K54C",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "K54C"),
+		},
+	},
+	{
+	.callback = init_nvs_nosave,
+	.ident = "Asus K54HR",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "K54HR"),
+		},
+	},
+	{
+	.callback = init_nvs_save_s3,
+	.ident = "Asus 1025C",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "1025C"),
+		},
+	},
+	/*
+	 * https://bugzilla.kernel.org/show_bug.cgi?id=189431
+	 * Lenovo G50-45 is a platform later than 2012, but needs nvs memory
+	 * saving during S3.
+	 */
+	{
+	.callback = init_nvs_save_s3,
+	.ident = "Lenovo G50-45",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "80E3"),
+		},
+	},
+	/*
+	 * https://bugzilla.kernel.org/show_bug.cgi?id=196907
+	 * Some Dell XPS13 9360 cannot do suspend-to-idle using the Low Power
+	 * S0 Idle firmware interface.
+	 */
+	{
+	.callback = init_no_lps0,
+	.ident = "Dell XPS13 9360",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "XPS 13 9360"),
+		},
+	},
+	/*
+	 * ThinkPad X1 Tablet(2016) cannot do suspend-to-idle using
+	 * the Low Power S0 Idle firmware interface (see
+	 * https://bugzilla.kernel.org/show_bug.cgi?id=199057).
+	 */
+	{
+	.callback = init_no_lps0,
+	.ident = "ThinkPad X1 Tablet(2016)",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "20GGA00L00"),
+		},
+	},
+	{},
+};
+
+static bool ignore_blacklist;
+
+void __init acpi_sleep_no_blacklist(void)
+{
+	ignore_blacklist = true;
+}
+
+static void __init acpi_sleep_dmi_check(void)
+{
+	if (ignore_blacklist)
+		return;
+
+	if (dmi_get_bios_year() >= 2012)
+		acpi_nvs_nosave_s3();
+
+	dmi_check_system(acpisleep_dmi_table);
+}
+
+/**
+ * acpi_pm_freeze - Disable the GPEs and suspend EC transactions.
+ */
+static int acpi_pm_freeze(void)
+{
+	acpi_disable_all_gpes();
+	acpi_os_wait_events_complete();
+	acpi_ec_block_transactions();
+	return 0;
+}
+
+/**
+ * acpi_pre_suspend - Enable wakeup devices, "freeze" EC and save NVS.
+ */
+static int acpi_pm_pre_suspend(void)
+{
+	acpi_pm_freeze();
+	return suspend_nvs_save();
+}
+
+/**
+ *	__acpi_pm_prepare - Prepare the platform to enter the target state.
+ *
+ *	If necessary, set the firmware waking vector and do arch-specific
+ *	nastiness to get the wakeup code to the waking vector.
+ */
+static int __acpi_pm_prepare(void)
+{
+	int error = acpi_sleep_prepare(acpi_target_sleep_state);
+	if (error)
+		acpi_target_sleep_state = ACPI_STATE_S0;
+
+	return error;
+}
+
+/**
+ *	acpi_pm_prepare - Prepare the platform to enter the target sleep
+ *		state and disable the GPEs.
+ */
+static int acpi_pm_prepare(void)
+{
+	int error = __acpi_pm_prepare();
+	if (!error)
+		error = acpi_pm_pre_suspend();
+
+	return error;
+}
+
+static int find_powerf_dev(struct device *dev, void *data)
+{
+	struct acpi_device *device = to_acpi_device(dev);
+	const char *hid = acpi_device_hid(device);
+
+	return !strcmp(hid, ACPI_BUTTON_HID_POWERF);
+}
+
+/**
+ *	acpi_pm_finish - Instruct the platform to leave a sleep state.
+ *
+ *	This is called after we wake back up (or if entering the sleep state
+ *	failed).
+ */
+static void acpi_pm_finish(void)
+{
+	struct device *pwr_btn_dev;
+	u32 acpi_state = acpi_target_sleep_state;
+
+	acpi_ec_unblock_transactions();
+	suspend_nvs_free();
+
+	if (acpi_state == ACPI_STATE_S0)
+		return;
+
+	printk(KERN_INFO PREFIX "Waking up from system sleep state S%d\n",
+		acpi_state);
+	acpi_disable_wakeup_devices(acpi_state);
+	acpi_leave_sleep_state(acpi_state);
+
+	/* reset firmware waking vector */
+	acpi_set_waking_vector(0);
+
+	acpi_target_sleep_state = ACPI_STATE_S0;
+
+	acpi_resume_power_resources();
+
+	/* If we were woken with the fixed power button, provide a small
+	 * hint to userspace in the form of a wakeup event on the fixed power
+	 * button device (if it can be found).
+	 *
+	 * We delay the event generation til now, as the PM layer requires
+	 * timekeeping to be running before we generate events. */
+	if (!pwr_btn_event_pending)
+		return;
+
+	pwr_btn_event_pending = false;
+	pwr_btn_dev = bus_find_device(&acpi_bus_type, NULL, NULL,
+				      find_powerf_dev);
+	if (pwr_btn_dev) {
+		pm_wakeup_event(pwr_btn_dev, 0);
+		put_device(pwr_btn_dev);
+	}
+}
+
+/**
+ * acpi_pm_start - Start system PM transition.
+ */
+static void acpi_pm_start(u32 acpi_state)
+{
+	acpi_target_sleep_state = acpi_state;
+	acpi_sleep_tts_switch(acpi_target_sleep_state);
+	acpi_scan_lock_acquire();
+}
+
+/**
+ * acpi_pm_end - Finish up system PM transition.
+ */
+static void acpi_pm_end(void)
+{
+	acpi_turn_off_unused_power_resources();
+	acpi_scan_lock_release();
+	/*
+	 * This is necessary in case acpi_pm_finish() is not called during a
+	 * failing transition to a sleep state.
+	 */
+	acpi_target_sleep_state = ACPI_STATE_S0;
+	acpi_sleep_tts_switch(acpi_target_sleep_state);
+}
+#else /* !CONFIG_ACPI_SLEEP */
+#define acpi_target_sleep_state	ACPI_STATE_S0
+#define acpi_sleep_no_lps0	(false)
+static inline void acpi_sleep_dmi_check(void) {}
+#endif /* CONFIG_ACPI_SLEEP */
+
+#ifdef CONFIG_SUSPEND
+static u32 acpi_suspend_states[] = {
+	[PM_SUSPEND_ON] = ACPI_STATE_S0,
+	[PM_SUSPEND_STANDBY] = ACPI_STATE_S1,
+	[PM_SUSPEND_MEM] = ACPI_STATE_S3,
+	[PM_SUSPEND_MAX] = ACPI_STATE_S5
+};
+
+/**
+ *	acpi_suspend_begin - Set the target system sleep state to the state
+ *		associated with given @pm_state, if supported.
+ */
+static int acpi_suspend_begin(suspend_state_t pm_state)
+{
+	u32 acpi_state = acpi_suspend_states[pm_state];
+	int error;
+
+	error = (nvs_nosave || nvs_nosave_s3) ? 0 : suspend_nvs_alloc();
+	if (error)
+		return error;
+
+	if (!sleep_states[acpi_state]) {
+		pr_err("ACPI does not support sleep state S%u\n", acpi_state);
+		return -ENOSYS;
+	}
+	if (acpi_state > ACPI_STATE_S1)
+		pm_set_suspend_via_firmware();
+
+	acpi_pm_start(acpi_state);
+	return 0;
+}
+
+/**
+ *	acpi_suspend_enter - Actually enter a sleep state.
+ *	@pm_state: ignored
+ *
+ *	Flush caches and go to sleep. For STR we have to call arch-specific
+ *	assembly, which in turn call acpi_enter_sleep_state().
+ *	It's unfortunate, but it works. Please fix if you're feeling frisky.
+ */
+static int acpi_suspend_enter(suspend_state_t pm_state)
+{
+	acpi_status status = AE_OK;
+	u32 acpi_state = acpi_target_sleep_state;
+	int error;
+
+	ACPI_FLUSH_CPU_CACHE();
+
+	trace_suspend_resume(TPS("acpi_suspend"), acpi_state, true);
+	switch (acpi_state) {
+	case ACPI_STATE_S1:
+		barrier();
+		status = acpi_enter_sleep_state(acpi_state);
+		break;
+
+	case ACPI_STATE_S3:
+		if (!acpi_suspend_lowlevel)
+			return -ENOSYS;
+		error = acpi_suspend_lowlevel();
+		if (error)
+			return error;
+		pr_info(PREFIX "Low-level resume complete\n");
+		pm_set_resume_via_firmware();
+		break;
+	}
+	trace_suspend_resume(TPS("acpi_suspend"), acpi_state, false);
+
+	/* This violates the spec but is required for bug compatibility. */
+	acpi_write_bit_register(ACPI_BITREG_SCI_ENABLE, 1);
+
+	/* Reprogram control registers */
+	acpi_leave_sleep_state_prep(acpi_state);
+
+	/* ACPI 3.0 specs (P62) says that it's the responsibility
+	 * of the OSPM to clear the status bit [ implying that the
+	 * POWER_BUTTON event should not reach userspace ]
+	 *
+	 * However, we do generate a small hint for userspace in the form of
+	 * a wakeup event. We flag this condition for now and generate the
+	 * event later, as we're currently too early in resume to be able to
+	 * generate wakeup events.
+	 */
+	if (ACPI_SUCCESS(status) && (acpi_state == ACPI_STATE_S3)) {
+		acpi_event_status pwr_btn_status = ACPI_EVENT_FLAG_DISABLED;
+
+		acpi_get_event_status(ACPI_EVENT_POWER_BUTTON, &pwr_btn_status);
+
+		if (pwr_btn_status & ACPI_EVENT_FLAG_STATUS_SET) {
+			acpi_clear_event(ACPI_EVENT_POWER_BUTTON);
+			/* Flag for later */
+			pwr_btn_event_pending = true;
+		}
+	}
+
+	/*
+	 * Disable and clear GPE status before interrupt is enabled. Some GPEs
+	 * (like wakeup GPE) haven't handler, this can avoid such GPE misfire.
+	 * acpi_leave_sleep_state will reenable specific GPEs later
+	 */
+	acpi_disable_all_gpes();
+	/* Allow EC transactions to happen. */
+	acpi_ec_unblock_transactions();
+
+	suspend_nvs_restore();
+
+	return ACPI_SUCCESS(status) ? 0 : -EFAULT;
+}
+
+static int acpi_suspend_state_valid(suspend_state_t pm_state)
+{
+	u32 acpi_state;
+
+	switch (pm_state) {
+	case PM_SUSPEND_ON:
+	case PM_SUSPEND_STANDBY:
+	case PM_SUSPEND_MEM:
+		acpi_state = acpi_suspend_states[pm_state];
+
+		return sleep_states[acpi_state];
+	default:
+		return 0;
+	}
+}
+
+static const struct platform_suspend_ops acpi_suspend_ops = {
+	.valid = acpi_suspend_state_valid,
+	.begin = acpi_suspend_begin,
+	.prepare_late = acpi_pm_prepare,
+	.enter = acpi_suspend_enter,
+	.wake = acpi_pm_finish,
+	.end = acpi_pm_end,
+};
+
+/**
+ *	acpi_suspend_begin_old - Set the target system sleep state to the
+ *		state associated with given @pm_state, if supported, and
+ *		execute the _PTS control method.  This function is used if the
+ *		pre-ACPI 2.0 suspend ordering has been requested.
+ */
+static int acpi_suspend_begin_old(suspend_state_t pm_state)
+{
+	int error = acpi_suspend_begin(pm_state);
+	if (!error)
+		error = __acpi_pm_prepare();
+
+	return error;
+}
+
+/*
+ * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
+ * been requested.
+ */
+static const struct platform_suspend_ops acpi_suspend_ops_old = {
+	.valid = acpi_suspend_state_valid,
+	.begin = acpi_suspend_begin_old,
+	.prepare_late = acpi_pm_pre_suspend,
+	.enter = acpi_suspend_enter,
+	.wake = acpi_pm_finish,
+	.end = acpi_pm_end,
+	.recover = acpi_pm_finish,
+};
+
+static bool s2idle_in_progress;
+static bool s2idle_wakeup;
+
+/*
+ * On platforms supporting the Low Power S0 Idle interface there is an ACPI
+ * device object with the PNP0D80 compatible device ID (System Power Management
+ * Controller) and a specific _DSM method under it.  That method, if present,
+ * can be used to indicate to the platform that the OS is transitioning into a
+ * low-power state in which certain types of activity are not desirable or that
+ * it is leaving such a state, which allows the platform to adjust its operation
+ * mode accordingly.
+ */
+static const struct acpi_device_id lps0_device_ids[] = {
+	{"PNP0D80", },
+	{"", },
+};
+
+#define ACPI_LPS0_DSM_UUID	"c4eb40a0-6cd2-11e2-bcfd-0800200c9a66"
+
+#define ACPI_LPS0_GET_DEVICE_CONSTRAINTS	1
+#define ACPI_LPS0_SCREEN_OFF	3
+#define ACPI_LPS0_SCREEN_ON	4
+#define ACPI_LPS0_ENTRY		5
+#define ACPI_LPS0_EXIT		6
+
+static acpi_handle lps0_device_handle;
+static guid_t lps0_dsm_guid;
+static char lps0_dsm_func_mask;
+
+/* Device constraint entry structure */
+struct lpi_device_info {
+	char *name;
+	int enabled;
+	union acpi_object *package;
+};
+
+/* Constraint package structure */
+struct lpi_device_constraint {
+	int uid;
+	int min_dstate;
+	int function_states;
+};
+
+struct lpi_constraints {
+	acpi_handle handle;
+	int min_dstate;
+};
+
+static struct lpi_constraints *lpi_constraints_table;
+static int lpi_constraints_table_size;
+
+static void lpi_device_get_constraints(void)
+{
+	union acpi_object *out_obj;
+	int i;
+
+	out_obj = acpi_evaluate_dsm_typed(lps0_device_handle, &lps0_dsm_guid,
+					  1, ACPI_LPS0_GET_DEVICE_CONSTRAINTS,
+					  NULL, ACPI_TYPE_PACKAGE);
+
+	acpi_handle_debug(lps0_device_handle, "_DSM function 1 eval %s\n",
+			  out_obj ? "successful" : "failed");
+
+	if (!out_obj)
+		return;
+
+	lpi_constraints_table = kcalloc(out_obj->package.count,
+					sizeof(*lpi_constraints_table),
+					GFP_KERNEL);
+	if (!lpi_constraints_table)
+		goto free_acpi_buffer;
+
+	acpi_handle_debug(lps0_device_handle, "LPI: constraints list begin:\n");
+
+	for (i = 0; i < out_obj->package.count; i++) {
+		struct lpi_constraints *constraint;
+		acpi_status status;
+		union acpi_object *package = &out_obj->package.elements[i];
+		struct lpi_device_info info = { };
+		int package_count = 0, j;
+
+		if (!package)
+			continue;
+
+		for (j = 0; j < package->package.count; ++j) {
+			union acpi_object *element =
+					&(package->package.elements[j]);
+
+			switch (element->type) {
+			case ACPI_TYPE_INTEGER:
+				info.enabled = element->integer.value;
+				break;
+			case ACPI_TYPE_STRING:
+				info.name = element->string.pointer;
+				break;
+			case ACPI_TYPE_PACKAGE:
+				package_count = element->package.count;
+				info.package = element->package.elements;
+				break;
+			}
+		}
+
+		if (!info.enabled || !info.package || !info.name)
+			continue;
+
+		constraint = &lpi_constraints_table[lpi_constraints_table_size];
+
+		status = acpi_get_handle(NULL, info.name, &constraint->handle);
+		if (ACPI_FAILURE(status))
+			continue;
+
+		acpi_handle_debug(lps0_device_handle,
+				  "index:%d Name:%s\n", i, info.name);
+
+		constraint->min_dstate = -1;
+
+		for (j = 0; j < package_count; ++j) {
+			union acpi_object *info_obj = &info.package[j];
+			union acpi_object *cnstr_pkg;
+			union acpi_object *obj;
+			struct lpi_device_constraint dev_info;
+
+			switch (info_obj->type) {
+			case ACPI_TYPE_INTEGER:
+				/* version */
+				break;
+			case ACPI_TYPE_PACKAGE:
+				if (info_obj->package.count < 2)
+					break;
+
+				cnstr_pkg = info_obj->package.elements;
+				obj = &cnstr_pkg[0];
+				dev_info.uid = obj->integer.value;
+				obj = &cnstr_pkg[1];
+				dev_info.min_dstate = obj->integer.value;
+
+				acpi_handle_debug(lps0_device_handle,
+					"uid:%d min_dstate:%s\n",
+					dev_info.uid,
+					acpi_power_state_string(dev_info.min_dstate));
+
+				constraint->min_dstate = dev_info.min_dstate;
+				break;
+			}
+		}
+
+		if (constraint->min_dstate < 0) {
+			acpi_handle_debug(lps0_device_handle,
+					  "Incomplete constraint defined\n");
+			continue;
+		}
+
+		lpi_constraints_table_size++;
+	}
+
+	acpi_handle_debug(lps0_device_handle, "LPI: constraints list end\n");
+
+free_acpi_buffer:
+	ACPI_FREE(out_obj);
+}
+
+static void lpi_check_constraints(void)
+{
+	int i;
+
+	for (i = 0; i < lpi_constraints_table_size; ++i) {
+		acpi_handle handle = lpi_constraints_table[i].handle;
+		struct acpi_device *adev;
+
+		if (!handle || acpi_bus_get_device(handle, &adev))
+			continue;
+
+		acpi_handle_debug(handle,
+			"LPI: required min power state:%s current power state:%s\n",
+			acpi_power_state_string(lpi_constraints_table[i].min_dstate),
+			acpi_power_state_string(adev->power.state));
+
+		if (!adev->flags.power_manageable) {
+			acpi_handle_info(handle, "LPI: Device not power manageable\n");
+			lpi_constraints_table[i].handle = NULL;
+			continue;
+		}
+
+		if (adev->power.state < lpi_constraints_table[i].min_dstate)
+			acpi_handle_info(handle,
+				"LPI: Constraint not met; min power state:%s current power state:%s\n",
+				acpi_power_state_string(lpi_constraints_table[i].min_dstate),
+				acpi_power_state_string(adev->power.state));
+	}
+}
+
+static void acpi_sleep_run_lps0_dsm(unsigned int func)
+{
+	union acpi_object *out_obj;
+
+	if (!(lps0_dsm_func_mask & (1 << func)))
+		return;
+
+	out_obj = acpi_evaluate_dsm(lps0_device_handle, &lps0_dsm_guid, 1, func, NULL);
+	ACPI_FREE(out_obj);
+
+	acpi_handle_debug(lps0_device_handle, "_DSM function %u evaluation %s\n",
+			  func, out_obj ? "successful" : "failed");
+}
+
+static int lps0_device_attach(struct acpi_device *adev,
+			      const struct acpi_device_id *not_used)
+{
+	union acpi_object *out_obj;
+
+	if (lps0_device_handle)
+		return 0;
+
+	if (acpi_sleep_no_lps0) {
+		acpi_handle_info(adev->handle,
+				 "Low Power S0 Idle interface disabled\n");
+		return 0;
+	}
+
+	if (!(acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0))
+		return 0;
+
+	guid_parse(ACPI_LPS0_DSM_UUID, &lps0_dsm_guid);
+	/* Check if the _DSM is present and as expected. */
+	out_obj = acpi_evaluate_dsm(adev->handle, &lps0_dsm_guid, 1, 0, NULL);
+	if (out_obj && out_obj->type == ACPI_TYPE_BUFFER) {
+		char bitmask = *(char *)out_obj->buffer.pointer;
+
+		lps0_dsm_func_mask = bitmask;
+		lps0_device_handle = adev->handle;
+		/*
+		 * Use suspend-to-idle by default if the default
+		 * suspend mode was not set from the command line.
+		 */
+		if (mem_sleep_default > PM_SUSPEND_MEM)
+			mem_sleep_current = PM_SUSPEND_TO_IDLE;
+
+		acpi_handle_debug(adev->handle, "_DSM function mask: 0x%x\n",
+				  bitmask);
+	} else {
+		acpi_handle_debug(adev->handle,
+				  "_DSM function 0 evaluation failed\n");
+	}
+	ACPI_FREE(out_obj);
+
+	lpi_device_get_constraints();
+
+	return 0;
+}
+
+static struct acpi_scan_handler lps0_handler = {
+	.ids = lps0_device_ids,
+	.attach = lps0_device_attach,
+};
+
+static int acpi_s2idle_begin(void)
+{
+	acpi_scan_lock_acquire();
+	s2idle_in_progress = true;
+	return 0;
+}
+
+static int acpi_s2idle_prepare(void)
+{
+	if (lps0_device_handle) {
+		acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF);
+		acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY);
+	}
+
+	if (acpi_sci_irq_valid())
+		enable_irq_wake(acpi_sci_irq);
+
+	return 0;
+}
+
+static void acpi_s2idle_wake(void)
+{
+
+	if (pm_debug_messages_on)
+		lpi_check_constraints();
+
+	/*
+	 * If IRQD_WAKEUP_ARMED is not set for the SCI at this point, it means
+	 * that the SCI has triggered while suspended, so cancel the wakeup in
+	 * case it has not been a wakeup event (the GPEs will be checked later).
+	 */
+	if (acpi_sci_irq_valid() &&
+	    !irqd_is_wakeup_armed(irq_get_irq_data(acpi_sci_irq))) {
+		pm_system_cancel_wakeup();
+		s2idle_wakeup = true;
+		/*
+		 * On some platforms with the LPS0 _DSM device noirq resume
+		 * takes too much time for EC wakeup events to survive, so look
+		 * for them now.
+		 */
+		if (lps0_device_handle)
+			acpi_ec_dispatch_gpe();
+	}
+}
+
+static void acpi_s2idle_sync(void)
+{
+	/*
+	 * Process all pending events in case there are any wakeup ones.
+	 *
+	 * The EC driver uses the system workqueue and an additional special
+	 * one, so those need to be flushed too.
+	 */
+	acpi_os_wait_events_complete();	/* synchronize SCI IRQ handling */
+	acpi_ec_flush_work();
+	acpi_os_wait_events_complete();	/* synchronize Notify handling */
+	s2idle_wakeup = false;
+}
+
+static void acpi_s2idle_restore(void)
+{
+	if (acpi_sci_irq_valid())
+		disable_irq_wake(acpi_sci_irq);
+
+	if (lps0_device_handle) {
+		acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT);
+		acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON);
+	}
+}
+
+static void acpi_s2idle_end(void)
+{
+	s2idle_in_progress = false;
+	acpi_scan_lock_release();
+}
+
+static const struct platform_s2idle_ops acpi_s2idle_ops = {
+	.begin = acpi_s2idle_begin,
+	.prepare = acpi_s2idle_prepare,
+	.wake = acpi_s2idle_wake,
+	.sync = acpi_s2idle_sync,
+	.restore = acpi_s2idle_restore,
+	.end = acpi_s2idle_end,
+};
+
+static void acpi_sleep_suspend_setup(void)
+{
+	int i;
+
+	for (i = ACPI_STATE_S1; i < ACPI_STATE_S4; i++)
+		if (acpi_sleep_state_supported(i))
+			sleep_states[i] = 1;
+
+	suspend_set_ops(old_suspend_ordering ?
+		&acpi_suspend_ops_old : &acpi_suspend_ops);
+
+	acpi_scan_add_handler(&lps0_handler);
+	s2idle_set_ops(&acpi_s2idle_ops);
+}
+
+#else /* !CONFIG_SUSPEND */
+#define s2idle_in_progress	(false)
+#define s2idle_wakeup		(false)
+#define lps0_device_handle	(NULL)
+static inline void acpi_sleep_suspend_setup(void) {}
+#endif /* !CONFIG_SUSPEND */
+
+bool acpi_s2idle_wakeup(void)
+{
+	return s2idle_wakeup;
+}
+
+bool acpi_sleep_no_ec_events(void)
+{
+	return !s2idle_in_progress || !lps0_device_handle;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static u32 saved_bm_rld;
+
+static int  acpi_save_bm_rld(void)
+{
+	acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
+	return 0;
+}
+
+static void  acpi_restore_bm_rld(void)
+{
+	u32 resumed_bm_rld = 0;
+
+	acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
+	if (resumed_bm_rld == saved_bm_rld)
+		return;
+
+	acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
+}
+
+static struct syscore_ops acpi_sleep_syscore_ops = {
+	.suspend = acpi_save_bm_rld,
+	.resume = acpi_restore_bm_rld,
+};
+
+static void acpi_sleep_syscore_init(void)
+{
+	register_syscore_ops(&acpi_sleep_syscore_ops);
+}
+#else
+static inline void acpi_sleep_syscore_init(void) {}
+#endif /* CONFIG_PM_SLEEP */
+
+#ifdef CONFIG_HIBERNATION
+static unsigned long s4_hardware_signature;
+static struct acpi_table_facs *facs;
+static bool nosigcheck;
+
+void __init acpi_no_s4_hw_signature(void)
+{
+	nosigcheck = true;
+}
+
+static int acpi_hibernation_begin(void)
+{
+	int error;
+
+	error = nvs_nosave ? 0 : suspend_nvs_alloc();
+	if (!error)
+		acpi_pm_start(ACPI_STATE_S4);
+
+	return error;
+}
+
+static int acpi_hibernation_enter(void)
+{
+	acpi_status status = AE_OK;
+
+	ACPI_FLUSH_CPU_CACHE();
+
+	/* This shouldn't return.  If it returns, we have a problem */
+	status = acpi_enter_sleep_state(ACPI_STATE_S4);
+	/* Reprogram control registers */
+	acpi_leave_sleep_state_prep(ACPI_STATE_S4);
+
+	return ACPI_SUCCESS(status) ? 0 : -EFAULT;
+}
+
+static void acpi_hibernation_leave(void)
+{
+	pm_set_resume_via_firmware();
+	/*
+	 * If ACPI is not enabled by the BIOS and the boot kernel, we need to
+	 * enable it here.
+	 */
+	acpi_enable();
+	/* Reprogram control registers */
+	acpi_leave_sleep_state_prep(ACPI_STATE_S4);
+	/* Check the hardware signature */
+	if (facs && s4_hardware_signature != facs->hardware_signature)
+		pr_crit("ACPI: Hardware changed while hibernated, success doubtful!\n");
+	/* Restore the NVS memory area */
+	suspend_nvs_restore();
+	/* Allow EC transactions to happen. */
+	acpi_ec_unblock_transactions();
+}
+
+static void acpi_pm_thaw(void)
+{
+	acpi_ec_unblock_transactions();
+	acpi_enable_all_runtime_gpes();
+}
+
+static const struct platform_hibernation_ops acpi_hibernation_ops = {
+	.begin = acpi_hibernation_begin,
+	.end = acpi_pm_end,
+	.pre_snapshot = acpi_pm_prepare,
+	.finish = acpi_pm_finish,
+	.prepare = acpi_pm_prepare,
+	.enter = acpi_hibernation_enter,
+	.leave = acpi_hibernation_leave,
+	.pre_restore = acpi_pm_freeze,
+	.restore_cleanup = acpi_pm_thaw,
+};
+
+/**
+ *	acpi_hibernation_begin_old - Set the target system sleep state to
+ *		ACPI_STATE_S4 and execute the _PTS control method.  This
+ *		function is used if the pre-ACPI 2.0 suspend ordering has been
+ *		requested.
+ */
+static int acpi_hibernation_begin_old(void)
+{
+	int error;
+	/*
+	 * The _TTS object should always be evaluated before the _PTS object.
+	 * When the old_suspended_ordering is true, the _PTS object is
+	 * evaluated in the acpi_sleep_prepare.
+	 */
+	acpi_sleep_tts_switch(ACPI_STATE_S4);
+
+	error = acpi_sleep_prepare(ACPI_STATE_S4);
+
+	if (!error) {
+		if (!nvs_nosave)
+			error = suspend_nvs_alloc();
+		if (!error) {
+			acpi_target_sleep_state = ACPI_STATE_S4;
+			acpi_scan_lock_acquire();
+		}
+	}
+	return error;
+}
+
+/*
+ * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
+ * been requested.
+ */
+static const struct platform_hibernation_ops acpi_hibernation_ops_old = {
+	.begin = acpi_hibernation_begin_old,
+	.end = acpi_pm_end,
+	.pre_snapshot = acpi_pm_pre_suspend,
+	.prepare = acpi_pm_freeze,
+	.finish = acpi_pm_finish,
+	.enter = acpi_hibernation_enter,
+	.leave = acpi_hibernation_leave,
+	.pre_restore = acpi_pm_freeze,
+	.restore_cleanup = acpi_pm_thaw,
+	.recover = acpi_pm_finish,
+};
+
+static void acpi_sleep_hibernate_setup(void)
+{
+	if (!acpi_sleep_state_supported(ACPI_STATE_S4))
+		return;
+
+	hibernation_set_ops(old_suspend_ordering ?
+			&acpi_hibernation_ops_old : &acpi_hibernation_ops);
+	sleep_states[ACPI_STATE_S4] = 1;
+	if (nosigcheck)
+		return;
+
+	acpi_get_table(ACPI_SIG_FACS, 1, (struct acpi_table_header **)&facs);
+	if (facs)
+		s4_hardware_signature = facs->hardware_signature;
+}
+#else /* !CONFIG_HIBERNATION */
+static inline void acpi_sleep_hibernate_setup(void) {}
+#endif /* !CONFIG_HIBERNATION */
+
+static void acpi_power_off_prepare(void)
+{
+	/* Prepare to power off the system */
+	acpi_sleep_prepare(ACPI_STATE_S5);
+	acpi_disable_all_gpes();
+	acpi_os_wait_events_complete();
+}
+
+static void acpi_power_off(void)
+{
+	/* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
+	printk(KERN_DEBUG "%s called\n", __func__);
+	local_irq_disable();
+	acpi_enter_sleep_state(ACPI_STATE_S5);
+}
+
+int __init acpi_sleep_init(void)
+{
+	char supported[ACPI_S_STATE_COUNT * 3 + 1];
+	char *pos = supported;
+	int i;
+
+	acpi_sleep_dmi_check();
+
+	sleep_states[ACPI_STATE_S0] = 1;
+
+	acpi_sleep_syscore_init();
+	acpi_sleep_suspend_setup();
+	acpi_sleep_hibernate_setup();
+
+	if (acpi_sleep_state_supported(ACPI_STATE_S5)) {
+		sleep_states[ACPI_STATE_S5] = 1;
+		pm_power_off_prepare = acpi_power_off_prepare;
+		pm_power_off = acpi_power_off;
+	} else {
+		acpi_no_s5 = true;
+	}
+
+	supported[0] = 0;
+	for (i = 0; i < ACPI_S_STATE_COUNT; i++) {
+		if (sleep_states[i])
+			pos += sprintf(pos, " S%d", i);
+	}
+	pr_info(PREFIX "(supports%s)\n", supported);
+
+	/*
+	 * Register the tts_notifier to reboot notifier list so that the _TTS
+	 * object can also be evaluated when the system enters S5.
+	 */
+	register_reboot_notifier(&tts_notifier);
+	return 0;
+}