Adding upstream version 4.19.249.upstream/4.19.249

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

1 files changed, 2378 insertions, 0 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
new file mode 100644
index 000000000..1e7e2c438
--- /dev/null
+++ b/drivers/acpi/scan.c
@@ -0,0 +1,2378 @@
+/*
+ * scan.c - support for transforming the ACPI namespace into individual objects
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/acpi.h>
+#include <linux/acpi_iort.h>
+#include <linux/signal.h>
+#include <linux/kthread.h>
+#include <linux/dmi.h>
+#include <linux/nls.h>
+#include <linux/dma-mapping.h>
+#include <linux/platform_data/x86/apple.h>
+
+#include <asm/pgtable.h>
+
+#include "internal.h"
+
+#define _COMPONENT		ACPI_BUS_COMPONENT
+ACPI_MODULE_NAME("scan");
+extern struct acpi_device *acpi_root;
+
+#define ACPI_BUS_CLASS			"system_bus"
+#define ACPI_BUS_HID			"LNXSYBUS"
+#define ACPI_BUS_DEVICE_NAME		"System Bus"
+
+#define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)
+
+#define INVALID_ACPI_HANDLE	((acpi_handle)empty_zero_page)
+
+static const char *dummy_hid = "device";
+
+static LIST_HEAD(acpi_dep_list);
+static DEFINE_MUTEX(acpi_dep_list_lock);
+LIST_HEAD(acpi_bus_id_list);
+static DEFINE_MUTEX(acpi_scan_lock);
+static LIST_HEAD(acpi_scan_handlers_list);
+DEFINE_MUTEX(acpi_device_lock);
+LIST_HEAD(acpi_wakeup_device_list);
+static DEFINE_MUTEX(acpi_hp_context_lock);
+
+/*
+ * The UART device described by the SPCR table is the only object which needs
+ * special-casing. Everything else is covered by ACPI namespace paths in STAO
+ * table.
+ */
+static u64 spcr_uart_addr;
+
+struct acpi_dep_data {
+	struct list_head node;
+	acpi_handle master;
+	acpi_handle slave;
+};
+
+void acpi_scan_lock_acquire(void)
+{
+	mutex_lock(&acpi_scan_lock);
+}
+EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
+
+void acpi_scan_lock_release(void)
+{
+	mutex_unlock(&acpi_scan_lock);
+}
+EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
+
+void acpi_lock_hp_context(void)
+{
+	mutex_lock(&acpi_hp_context_lock);
+}
+
+void acpi_unlock_hp_context(void)
+{
+	mutex_unlock(&acpi_hp_context_lock);
+}
+
+void acpi_initialize_hp_context(struct acpi_device *adev,
+				struct acpi_hotplug_context *hp,
+				int (*notify)(struct acpi_device *, u32),
+				void (*uevent)(struct acpi_device *, u32))
+{
+	acpi_lock_hp_context();
+	hp->notify = notify;
+	hp->uevent = uevent;
+	acpi_set_hp_context(adev, hp);
+	acpi_unlock_hp_context();
+}
+EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
+
+int acpi_scan_add_handler(struct acpi_scan_handler *handler)
+{
+	if (!handler)
+		return -EINVAL;
+
+	list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
+	return 0;
+}
+
+int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
+				       const char *hotplug_profile_name)
+{
+	int error;
+
+	error = acpi_scan_add_handler(handler);
+	if (error)
+		return error;
+
+	acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
+	return 0;
+}
+
+bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
+{
+	struct acpi_device_physical_node *pn;
+	bool offline = true;
+	char *envp[] = { "EVENT=offline", NULL };
+
+	/*
+	 * acpi_container_offline() calls this for all of the container's
+	 * children under the container's physical_node_lock lock.
+	 */
+	mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
+
+	list_for_each_entry(pn, &adev->physical_node_list, node)
+		if (device_supports_offline(pn->dev) && !pn->dev->offline) {
+			if (uevent)
+				kobject_uevent_env(&pn->dev->kobj, KOBJ_CHANGE, envp);
+
+			offline = false;
+			break;
+		}
+
+	mutex_unlock(&adev->physical_node_lock);
+	return offline;
+}
+
+static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
+				    void **ret_p)
+{
+	struct acpi_device *device = NULL;
+	struct acpi_device_physical_node *pn;
+	bool second_pass = (bool)data;
+	acpi_status status = AE_OK;
+
+	if (acpi_bus_get_device(handle, &device))
+		return AE_OK;
+
+	if (device->handler && !device->handler->hotplug.enabled) {
+		*ret_p = &device->dev;
+		return AE_SUPPORT;
+	}
+
+	mutex_lock(&device->physical_node_lock);
+
+	list_for_each_entry(pn, &device->physical_node_list, node) {
+		int ret;
+
+		if (second_pass) {
+			/* Skip devices offlined by the first pass. */
+			if (pn->put_online)
+				continue;
+		} else {
+			pn->put_online = false;
+		}
+		ret = device_offline(pn->dev);
+		if (ret >= 0) {
+			pn->put_online = !ret;
+		} else {
+			*ret_p = pn->dev;
+			if (second_pass) {
+				status = AE_ERROR;
+				break;
+			}
+		}
+	}
+
+	mutex_unlock(&device->physical_node_lock);
+
+	return status;
+}
+
+static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
+				   void **ret_p)
+{
+	struct acpi_device *device = NULL;
+	struct acpi_device_physical_node *pn;
+
+	if (acpi_bus_get_device(handle, &device))
+		return AE_OK;
+
+	mutex_lock(&device->physical_node_lock);
+
+	list_for_each_entry(pn, &device->physical_node_list, node)
+		if (pn->put_online) {
+			device_online(pn->dev);
+			pn->put_online = false;
+		}
+
+	mutex_unlock(&device->physical_node_lock);
+
+	return AE_OK;
+}
+
+static int acpi_scan_try_to_offline(struct acpi_device *device)
+{
+	acpi_handle handle = device->handle;
+	struct device *errdev = NULL;
+	acpi_status status;
+
+	/*
+	 * Carry out two passes here and ignore errors in the first pass,
+	 * because if the devices in question are memory blocks and
+	 * CONFIG_MEMCG is set, one of the blocks may hold data structures
+	 * that the other blocks depend on, but it is not known in advance which
+	 * block holds them.
+	 *
+	 * If the first pass is successful, the second one isn't needed, though.
+	 */
+	status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
+				     NULL, acpi_bus_offline, (void *)false,
+				     (void **)&errdev);
+	if (status == AE_SUPPORT) {
+		dev_warn(errdev, "Offline disabled.\n");
+		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
+				    acpi_bus_online, NULL, NULL, NULL);
+		return -EPERM;
+	}
+	acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
+	if (errdev) {
+		errdev = NULL;
+		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
+				    NULL, acpi_bus_offline, (void *)true,
+				    (void **)&errdev);
+		if (!errdev)
+			acpi_bus_offline(handle, 0, (void *)true,
+					 (void **)&errdev);
+
+		if (errdev) {
+			dev_warn(errdev, "Offline failed.\n");
+			acpi_bus_online(handle, 0, NULL, NULL);
+			acpi_walk_namespace(ACPI_TYPE_ANY, handle,
+					    ACPI_UINT32_MAX, acpi_bus_online,
+					    NULL, NULL, NULL);
+			return -EBUSY;
+		}
+	}
+	return 0;
+}
+
+static int acpi_scan_hot_remove(struct acpi_device *device)
+{
+	acpi_handle handle = device->handle;
+	unsigned long long sta;
+	acpi_status status;
+
+	if (device->handler && device->handler->hotplug.demand_offline) {
+		if (!acpi_scan_is_offline(device, true))
+			return -EBUSY;
+	} else {
+		int error = acpi_scan_try_to_offline(device);
+		if (error)
+			return error;
+	}
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+		"Hot-removing device %s...\n", dev_name(&device->dev)));
+
+	acpi_bus_trim(device);
+
+	acpi_evaluate_lck(handle, 0);
+	/*
+	 * TBD: _EJD support.
+	 */
+	status = acpi_evaluate_ej0(handle);
+	if (status == AE_NOT_FOUND)
+		return -ENODEV;
+	else if (ACPI_FAILURE(status))
+		return -EIO;
+
+	/*
+	 * Verify if eject was indeed successful.  If not, log an error
+	 * message.  No need to call _OST since _EJ0 call was made OK.
+	 */
+	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
+	if (ACPI_FAILURE(status)) {
+		acpi_handle_warn(handle,
+			"Status check after eject failed (0x%x)\n", status);
+	} else if (sta & ACPI_STA_DEVICE_ENABLED) {
+		acpi_handle_warn(handle,
+			"Eject incomplete - status 0x%llx\n", sta);
+	}
+
+	return 0;
+}
+
+static int acpi_scan_device_not_present(struct acpi_device *adev)
+{
+	if (!acpi_device_enumerated(adev)) {
+		dev_warn(&adev->dev, "Still not present\n");
+		return -EALREADY;
+	}
+	acpi_bus_trim(adev);
+	return 0;
+}
+
+static int acpi_scan_device_check(struct acpi_device *adev)
+{
+	int error;
+
+	acpi_bus_get_status(adev);
+	if (adev->status.present || adev->status.functional) {
+		/*
+		 * This function is only called for device objects for which
+		 * matching scan handlers exist.  The only situation in which
+		 * the scan handler is not attached to this device object yet
+		 * is when the device has just appeared (either it wasn't
+		 * present at all before or it was removed and then added
+		 * again).
+		 */
+		if (adev->handler) {
+			dev_warn(&adev->dev, "Already enumerated\n");
+			return -EALREADY;
+		}
+		error = acpi_bus_scan(adev->handle);
+		if (error) {
+			dev_warn(&adev->dev, "Namespace scan failure\n");
+			return error;
+		}
+		if (!adev->handler) {
+			dev_warn(&adev->dev, "Enumeration failure\n");
+			error = -ENODEV;
+		}
+	} else {
+		error = acpi_scan_device_not_present(adev);
+	}
+	return error;
+}
+
+static int acpi_scan_bus_check(struct acpi_device *adev)
+{
+	struct acpi_scan_handler *handler = adev->handler;
+	struct acpi_device *child;
+	int error;
+
+	acpi_bus_get_status(adev);
+	if (!(adev->status.present || adev->status.functional)) {
+		acpi_scan_device_not_present(adev);
+		return 0;
+	}
+	if (handler && handler->hotplug.scan_dependent)
+		return handler->hotplug.scan_dependent(adev);
+
+	error = acpi_bus_scan(adev->handle);
+	if (error) {
+		dev_warn(&adev->dev, "Namespace scan failure\n");
+		return error;
+	}
+	list_for_each_entry(child, &adev->children, node) {
+		error = acpi_scan_bus_check(child);
+		if (error)
+			return error;
+	}
+	return 0;
+}
+
+static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
+{
+	switch (type) {
+	case ACPI_NOTIFY_BUS_CHECK:
+		return acpi_scan_bus_check(adev);
+	case ACPI_NOTIFY_DEVICE_CHECK:
+		return acpi_scan_device_check(adev);
+	case ACPI_NOTIFY_EJECT_REQUEST:
+	case ACPI_OST_EC_OSPM_EJECT:
+		if (adev->handler && !adev->handler->hotplug.enabled) {
+			dev_info(&adev->dev, "Eject disabled\n");
+			return -EPERM;
+		}
+		acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
+				  ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
+		return acpi_scan_hot_remove(adev);
+	}
+	return -EINVAL;
+}
+
+void acpi_device_hotplug(struct acpi_device *adev, u32 src)
+{
+	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
+	int error = -ENODEV;
+
+	lock_device_hotplug();
+	mutex_lock(&acpi_scan_lock);
+
+	/*
+	 * The device object's ACPI handle cannot become invalid as long as we
+	 * are holding acpi_scan_lock, but it might have become invalid before
+	 * that lock was acquired.
+	 */
+	if (adev->handle == INVALID_ACPI_HANDLE)
+		goto err_out;
+
+	if (adev->flags.is_dock_station) {
+		error = dock_notify(adev, src);
+	} else if (adev->flags.hotplug_notify) {
+		error = acpi_generic_hotplug_event(adev, src);
+	} else {
+		int (*notify)(struct acpi_device *, u32);
+
+		acpi_lock_hp_context();
+		notify = adev->hp ? adev->hp->notify : NULL;
+		acpi_unlock_hp_context();
+		/*
+		 * There may be additional notify handlers for device objects
+		 * without the .event() callback, so ignore them here.
+		 */
+		if (notify)
+			error = notify(adev, src);
+		else
+			goto out;
+	}
+	switch (error) {
+	case 0:
+		ost_code = ACPI_OST_SC_SUCCESS;
+		break;
+	case -EPERM:
+		ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
+		break;
+	case -EBUSY:
+		ost_code = ACPI_OST_SC_DEVICE_BUSY;
+		break;
+	default:
+		ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
+		break;
+	}
+
+ err_out:
+	acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
+
+ out:
+	acpi_bus_put_acpi_device(adev);
+	mutex_unlock(&acpi_scan_lock);
+	unlock_device_hotplug();
+}
+
+static void acpi_free_power_resources_lists(struct acpi_device *device)
+{
+	int i;
+
+	if (device->wakeup.flags.valid)
+		acpi_power_resources_list_free(&device->wakeup.resources);
+
+	if (!device->power.flags.power_resources)
+		return;
+
+	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
+		struct acpi_device_power_state *ps = &device->power.states[i];
+		acpi_power_resources_list_free(&ps->resources);
+	}
+}
+
+static void acpi_device_release(struct device *dev)
+{
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+
+	acpi_free_properties(acpi_dev);
+	acpi_free_pnp_ids(&acpi_dev->pnp);
+	acpi_free_power_resources_lists(acpi_dev);
+	kfree(acpi_dev);
+}
+
+static void acpi_device_del(struct acpi_device *device)
+{
+	struct acpi_device_bus_id *acpi_device_bus_id;
+
+	mutex_lock(&acpi_device_lock);
+	if (device->parent)
+		list_del(&device->node);
+
+	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
+		if (!strcmp(acpi_device_bus_id->bus_id,
+			    acpi_device_hid(device))) {
+			ida_simple_remove(&acpi_device_bus_id->instance_ida, device->pnp.instance_no);
+			if (ida_is_empty(&acpi_device_bus_id->instance_ida)) {
+				list_del(&acpi_device_bus_id->node);
+				kfree_const(acpi_device_bus_id->bus_id);
+				kfree(acpi_device_bus_id);
+			}
+			break;
+		}
+
+	list_del(&device->wakeup_list);
+	mutex_unlock(&acpi_device_lock);
+
+	acpi_power_add_remove_device(device, false);
+	acpi_device_remove_files(device);
+	if (device->remove)
+		device->remove(device);
+
+	device_del(&device->dev);
+}
+
+static BLOCKING_NOTIFIER_HEAD(acpi_reconfig_chain);
+
+static LIST_HEAD(acpi_device_del_list);
+static DEFINE_MUTEX(acpi_device_del_lock);
+
+static void acpi_device_del_work_fn(struct work_struct *work_not_used)
+{
+	for (;;) {
+		struct acpi_device *adev;
+
+		mutex_lock(&acpi_device_del_lock);
+
+		if (list_empty(&acpi_device_del_list)) {
+			mutex_unlock(&acpi_device_del_lock);
+			break;
+		}
+		adev = list_first_entry(&acpi_device_del_list,
+					struct acpi_device, del_list);
+		list_del(&adev->del_list);
+
+		mutex_unlock(&acpi_device_del_lock);
+
+		blocking_notifier_call_chain(&acpi_reconfig_chain,
+					     ACPI_RECONFIG_DEVICE_REMOVE, adev);
+
+		acpi_device_del(adev);
+		/*
+		 * Drop references to all power resources that might have been
+		 * used by the device.
+		 */
+		acpi_power_transition(adev, ACPI_STATE_D3_COLD);
+		put_device(&adev->dev);
+	}
+}
+
+/**
+ * acpi_scan_drop_device - Drop an ACPI device object.
+ * @handle: Handle of an ACPI namespace node, not used.
+ * @context: Address of the ACPI device object to drop.
+ *
+ * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
+ * namespace node the device object pointed to by @context is attached to.
+ *
+ * The unregistration is carried out asynchronously to avoid running
+ * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
+ * ensure the correct ordering (the device objects must be unregistered in the
+ * same order in which the corresponding namespace nodes are deleted).
+ */
+static void acpi_scan_drop_device(acpi_handle handle, void *context)
+{
+	static DECLARE_WORK(work, acpi_device_del_work_fn);
+	struct acpi_device *adev = context;
+
+	mutex_lock(&acpi_device_del_lock);
+
+	/*
+	 * Use the ACPI hotplug workqueue which is ordered, so this work item
+	 * won't run after any hotplug work items submitted subsequently.  That
+	 * prevents attempts to register device objects identical to those being
+	 * deleted from happening concurrently (such attempts result from
+	 * hotplug events handled via the ACPI hotplug workqueue).  It also will
+	 * run after all of the work items submitted previosuly, which helps
+	 * those work items to ensure that they are not accessing stale device
+	 * objects.
+	 */
+	if (list_empty(&acpi_device_del_list))
+		acpi_queue_hotplug_work(&work);
+
+	list_add_tail(&adev->del_list, &acpi_device_del_list);
+	/* Make acpi_ns_validate_handle() return NULL for this handle. */
+	adev->handle = INVALID_ACPI_HANDLE;
+
+	mutex_unlock(&acpi_device_del_lock);
+}
+
+static int acpi_get_device_data(acpi_handle handle, struct acpi_device **device,
+				void (*callback)(void *))
+{
+	acpi_status status;
+
+	if (!device)
+		return -EINVAL;
+
+	*device = NULL;
+
+	status = acpi_get_data_full(handle, acpi_scan_drop_device,
+				    (void **)device, callback);
+	if (ACPI_FAILURE(status) || !*device) {
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
+				  handle));
+		return -ENODEV;
+	}
+	return 0;
+}
+
+int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
+{
+	return acpi_get_device_data(handle, device, NULL);
+}
+EXPORT_SYMBOL(acpi_bus_get_device);
+
+static void get_acpi_device(void *dev)
+{
+	if (dev)
+		get_device(&((struct acpi_device *)dev)->dev);
+}
+
+struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
+{
+	struct acpi_device *adev = NULL;
+
+	acpi_get_device_data(handle, &adev, get_acpi_device);
+	return adev;
+}
+
+void acpi_bus_put_acpi_device(struct acpi_device *adev)
+{
+	put_device(&adev->dev);
+}
+
+static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id)
+{
+	struct acpi_device_bus_id *acpi_device_bus_id;
+
+	/* Find suitable bus_id and instance number in acpi_bus_id_list. */
+	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
+		if (!strcmp(acpi_device_bus_id->bus_id, dev_id))
+			return acpi_device_bus_id;
+	}
+	return NULL;
+}
+
+static int acpi_device_set_name(struct acpi_device *device,
+				struct acpi_device_bus_id *acpi_device_bus_id)
+{
+	struct ida *instance_ida = &acpi_device_bus_id->instance_ida;
+	int result;
+
+	result = ida_simple_get(instance_ida, 0, ACPI_MAX_DEVICE_INSTANCES, GFP_KERNEL);
+	if (result < 0)
+		return result;
+
+	device->pnp.instance_no = result;
+	dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, result);
+	return 0;
+}
+
+int acpi_device_add(struct acpi_device *device,
+		    void (*release)(struct device *))
+{
+	struct acpi_device_bus_id *acpi_device_bus_id;
+	int result;
+
+	if (device->handle) {
+		acpi_status status;
+
+		status = acpi_attach_data(device->handle, acpi_scan_drop_device,
+					  device);
+		if (ACPI_FAILURE(status)) {
+			acpi_handle_err(device->handle,
+					"Unable to attach device data\n");
+			return -ENODEV;
+		}
+	}
+
+	/*
+	 * Linkage
+	 * -------
+	 * Link this device to its parent and siblings.
+	 */
+	INIT_LIST_HEAD(&device->children);
+	INIT_LIST_HEAD(&device->node);
+	INIT_LIST_HEAD(&device->wakeup_list);
+	INIT_LIST_HEAD(&device->physical_node_list);
+	INIT_LIST_HEAD(&device->del_list);
+	mutex_init(&device->physical_node_lock);
+
+	mutex_lock(&acpi_device_lock);
+
+	acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device));
+	if (acpi_device_bus_id) {
+		result = acpi_device_set_name(device, acpi_device_bus_id);
+		if (result)
+			goto err_unlock;
+	} else {
+		acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id),
+					     GFP_KERNEL);
+		if (!acpi_device_bus_id) {
+			result = -ENOMEM;
+			goto err_unlock;
+		}
+		acpi_device_bus_id->bus_id =
+			kstrdup_const(acpi_device_hid(device), GFP_KERNEL);
+		if (!acpi_device_bus_id->bus_id) {
+			kfree(acpi_device_bus_id);
+			result = -ENOMEM;
+			goto err_unlock;
+		}
+
+		ida_init(&acpi_device_bus_id->instance_ida);
+
+		result = acpi_device_set_name(device, acpi_device_bus_id);
+		if (result) {
+			kfree_const(acpi_device_bus_id->bus_id);
+			kfree(acpi_device_bus_id);
+			goto err_unlock;
+		}
+
+		list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
+	}
+
+	if (device->parent)
+		list_add_tail(&device->node, &device->parent->children);
+
+	if (device->wakeup.flags.valid)
+		list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
+	mutex_unlock(&acpi_device_lock);
+
+	if (device->parent)
+		device->dev.parent = &device->parent->dev;
+	device->dev.bus = &acpi_bus_type;
+	device->dev.release = release;
+	result = device_add(&device->dev);
+	if (result) {
+		dev_err(&device->dev, "Error registering device\n");
+		goto err;
+	}
+
+	result = acpi_device_setup_files(device);
+	if (result)
+		printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
+		       dev_name(&device->dev));
+
+	return 0;
+
+ err:
+	mutex_lock(&acpi_device_lock);
+	if (device->parent)
+		list_del(&device->node);
+	list_del(&device->wakeup_list);
+
+ err_unlock:
+	mutex_unlock(&acpi_device_lock);
+
+	acpi_detach_data(device->handle, acpi_scan_drop_device);
+	return result;
+}
+
+/* --------------------------------------------------------------------------
+                                 Device Enumeration
+   -------------------------------------------------------------------------- */
+static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
+{
+	struct acpi_device *device = NULL;
+	acpi_status status;
+
+	/*
+	 * Fixed hardware devices do not appear in the namespace and do not
+	 * have handles, but we fabricate acpi_devices for them, so we have
+	 * to deal with them specially.
+	 */
+	if (!handle)
+		return acpi_root;
+
+	do {
+		status = acpi_get_parent(handle, &handle);
+		if (ACPI_FAILURE(status))
+			return status == AE_NULL_ENTRY ? NULL : acpi_root;
+	} while (acpi_bus_get_device(handle, &device));
+	return device;
+}
+
+acpi_status
+acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
+{
+	acpi_status status;
+	acpi_handle tmp;
+	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+	union acpi_object *obj;
+
+	status = acpi_get_handle(handle, "_EJD", &tmp);
+	if (ACPI_FAILURE(status))
+		return status;
+
+	status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
+	if (ACPI_SUCCESS(status)) {
+		obj = buffer.pointer;
+		status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
+					 ejd);
+		kfree(buffer.pointer);
+	}
+	return status;
+}
+EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
+
+static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
+					struct acpi_device_wakeup *wakeup)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *package = NULL;
+	union acpi_object *element = NULL;
+	acpi_status status;
+	int err = -ENODATA;
+
+	if (!wakeup)
+		return -EINVAL;
+
+	INIT_LIST_HEAD(&wakeup->resources);
+
+	/* _PRW */
+	status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
+	if (ACPI_FAILURE(status)) {
+		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
+		return err;
+	}
+
+	package = (union acpi_object *)buffer.pointer;
+
+	if (!package || package->package.count < 2)
+		goto out;
+
+	element = &(package->package.elements[0]);
+	if (!element)
+		goto out;
+
+	if (element->type == ACPI_TYPE_PACKAGE) {
+		if ((element->package.count < 2) ||
+		    (element->package.elements[0].type !=
+		     ACPI_TYPE_LOCAL_REFERENCE)
+		    || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
+			goto out;
+
+		wakeup->gpe_device =
+		    element->package.elements[0].reference.handle;
+		wakeup->gpe_number =
+		    (u32) element->package.elements[1].integer.value;
+	} else if (element->type == ACPI_TYPE_INTEGER) {
+		wakeup->gpe_device = NULL;
+		wakeup->gpe_number = element->integer.value;
+	} else {
+		goto out;
+	}
+
+	element = &(package->package.elements[1]);
+	if (element->type != ACPI_TYPE_INTEGER)
+		goto out;
+
+	wakeup->sleep_state = element->integer.value;
+
+	err = acpi_extract_power_resources(package, 2, &wakeup->resources);
+	if (err)
+		goto out;
+
+	if (!list_empty(&wakeup->resources)) {
+		int sleep_state;
+
+		err = acpi_power_wakeup_list_init(&wakeup->resources,
+						  &sleep_state);
+		if (err) {
+			acpi_handle_warn(handle, "Retrieving current states "
+					 "of wakeup power resources failed\n");
+			acpi_power_resources_list_free(&wakeup->resources);
+			goto out;
+		}
+		if (sleep_state < wakeup->sleep_state) {
+			acpi_handle_warn(handle, "Overriding _PRW sleep state "
+					 "(S%d) by S%d from power resources\n",
+					 (int)wakeup->sleep_state, sleep_state);
+			wakeup->sleep_state = sleep_state;
+		}
+	}
+
+ out:
+	kfree(buffer.pointer);
+	return err;
+}
+
+static bool acpi_wakeup_gpe_init(struct acpi_device *device)
+{
+	static const struct acpi_device_id button_device_ids[] = {
+		{"PNP0C0C", 0},
+		{"PNP0C0D", 0},
+		{"PNP0C0E", 0},
+		{"", 0},
+	};
+	struct acpi_device_wakeup *wakeup = &device->wakeup;
+	acpi_status status;
+
+	wakeup->flags.notifier_present = 0;
+
+	/* Power button, Lid switch always enable wakeup */
+	if (!acpi_match_device_ids(device, button_device_ids)) {
+		if (!acpi_match_device_ids(device, &button_device_ids[1])) {
+			/* Do not use Lid/sleep button for S5 wakeup */
+			if (wakeup->sleep_state == ACPI_STATE_S5)
+				wakeup->sleep_state = ACPI_STATE_S4;
+		}
+		acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
+		device_set_wakeup_capable(&device->dev, true);
+		return true;
+	}
+
+	status = acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
+					 wakeup->gpe_number);
+	return ACPI_SUCCESS(status);
+}
+
+static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
+{
+	int err;
+
+	/* Presence of _PRW indicates wake capable */
+	if (!acpi_has_method(device->handle, "_PRW"))
+		return;
+
+	err = acpi_bus_extract_wakeup_device_power_package(device->handle,
+							   &device->wakeup);
+	if (err) {
+		dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
+		return;
+	}
+
+	device->wakeup.flags.valid = acpi_wakeup_gpe_init(device);
+	device->wakeup.prepare_count = 0;
+	/*
+	 * Call _PSW/_DSW object to disable its ability to wake the sleeping
+	 * system for the ACPI device with the _PRW object.
+	 * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
+	 * So it is necessary to call _DSW object first. Only when it is not
+	 * present will the _PSW object used.
+	 */
+	err = acpi_device_sleep_wake(device, 0, 0, 0);
+	if (err)
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+				"error in _DSW or _PSW evaluation\n"));
+}
+
+static void acpi_bus_init_power_state(struct acpi_device *device, int state)
+{
+	struct acpi_device_power_state *ps = &device->power.states[state];
+	char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	acpi_status status;
+
+	INIT_LIST_HEAD(&ps->resources);
+
+	/* Evaluate "_PRx" to get referenced power resources */
+	status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
+	if (ACPI_SUCCESS(status)) {
+		union acpi_object *package = buffer.pointer;
+
+		if (buffer.length && package
+		    && package->type == ACPI_TYPE_PACKAGE
+		    && package->package.count)
+			acpi_extract_power_resources(package, 0, &ps->resources);
+
+		ACPI_FREE(buffer.pointer);
+	}
+
+	/* Evaluate "_PSx" to see if we can do explicit sets */
+	pathname[2] = 'S';
+	if (acpi_has_method(device->handle, pathname))
+		ps->flags.explicit_set = 1;
+
+	/* State is valid if there are means to put the device into it. */
+	if (!list_empty(&ps->resources) || ps->flags.explicit_set)
+		ps->flags.valid = 1;
+
+	ps->power = -1;		/* Unknown - driver assigned */
+	ps->latency = -1;	/* Unknown - driver assigned */
+}
+
+static void acpi_bus_get_power_flags(struct acpi_device *device)
+{
+	u32 i;
+
+	/* Presence of _PS0|_PR0 indicates 'power manageable' */
+	if (!acpi_has_method(device->handle, "_PS0") &&
+	    !acpi_has_method(device->handle, "_PR0"))
+		return;
+
+	device->flags.power_manageable = 1;
+
+	/*
+	 * Power Management Flags
+	 */
+	if (acpi_has_method(device->handle, "_PSC"))
+		device->power.flags.explicit_get = 1;
+
+	if (acpi_has_method(device->handle, "_IRC"))
+		device->power.flags.inrush_current = 1;
+
+	if (acpi_has_method(device->handle, "_DSW"))
+		device->power.flags.dsw_present = 1;
+
+	/*
+	 * Enumerate supported power management states
+	 */
+	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
+		acpi_bus_init_power_state(device, i);
+
+	INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
+
+	/* Set the defaults for D0 and D3hot (always supported). */
+	device->power.states[ACPI_STATE_D0].flags.valid = 1;
+	device->power.states[ACPI_STATE_D0].power = 100;
+	device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
+
+	/*
+	 * Use power resources only if the D0 list of them is populated, because
+	 * some platforms may provide _PR3 only to indicate D3cold support and
+	 * in those cases the power resources list returned by it may be bogus.
+	 */
+	if (!list_empty(&device->power.states[ACPI_STATE_D0].resources)) {
+		device->power.flags.power_resources = 1;
+		/*
+		 * D3cold is supported if the D3hot list of power resources is
+		 * not empty.
+		 */
+		if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
+			device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
+	}
+
+	if (acpi_bus_init_power(device))
+		device->flags.power_manageable = 0;
+}
+
+static void acpi_bus_get_flags(struct acpi_device *device)
+{
+	/* Presence of _STA indicates 'dynamic_status' */
+	if (acpi_has_method(device->handle, "_STA"))
+		device->flags.dynamic_status = 1;
+
+	/* Presence of _RMV indicates 'removable' */
+	if (acpi_has_method(device->handle, "_RMV"))
+		device->flags.removable = 1;
+
+	/* Presence of _EJD|_EJ0 indicates 'ejectable' */
+	if (acpi_has_method(device->handle, "_EJD") ||
+	    acpi_has_method(device->handle, "_EJ0"))
+		device->flags.ejectable = 1;
+}
+
+static void acpi_device_get_busid(struct acpi_device *device)
+{
+	char bus_id[5] = { '?', 0 };
+	struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
+	int i = 0;
+
+	/*
+	 * Bus ID
+	 * ------
+	 * The device's Bus ID is simply the object name.
+	 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
+	 */
+	if (ACPI_IS_ROOT_DEVICE(device)) {
+		strcpy(device->pnp.bus_id, "ACPI");
+		return;
+	}
+
+	switch (device->device_type) {
+	case ACPI_BUS_TYPE_POWER_BUTTON:
+		strcpy(device->pnp.bus_id, "PWRF");
+		break;
+	case ACPI_BUS_TYPE_SLEEP_BUTTON:
+		strcpy(device->pnp.bus_id, "SLPF");
+		break;
+	case ACPI_BUS_TYPE_ECDT_EC:
+		strcpy(device->pnp.bus_id, "ECDT");
+		break;
+	default:
+		acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
+		/* Clean up trailing underscores (if any) */
+		for (i = 3; i > 1; i--) {
+			if (bus_id[i] == '_')
+				bus_id[i] = '\0';
+			else
+				break;
+		}
+		strcpy(device->pnp.bus_id, bus_id);
+		break;
+	}
+}
+
+/*
+ * acpi_ata_match - see if an acpi object is an ATA device
+ *
+ * If an acpi object has one of the ACPI ATA methods defined,
+ * then we can safely call it an ATA device.
+ */
+bool acpi_ata_match(acpi_handle handle)
+{
+	return acpi_has_method(handle, "_GTF") ||
+	       acpi_has_method(handle, "_GTM") ||
+	       acpi_has_method(handle, "_STM") ||
+	       acpi_has_method(handle, "_SDD");
+}
+
+/*
+ * acpi_bay_match - see if an acpi object is an ejectable driver bay
+ *
+ * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
+ * then we can safely call it an ejectable drive bay
+ */
+bool acpi_bay_match(acpi_handle handle)
+{
+	acpi_handle phandle;
+
+	if (!acpi_has_method(handle, "_EJ0"))
+		return false;
+	if (acpi_ata_match(handle))
+		return true;
+	if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
+		return false;
+
+	return acpi_ata_match(phandle);
+}
+
+bool acpi_device_is_battery(struct acpi_device *adev)
+{
+	struct acpi_hardware_id *hwid;
+
+	list_for_each_entry(hwid, &adev->pnp.ids, list)
+		if (!strcmp("PNP0C0A", hwid->id))
+			return true;
+
+	return false;
+}
+
+static bool is_ejectable_bay(struct acpi_device *adev)
+{
+	acpi_handle handle = adev->handle;
+
+	if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
+		return true;
+
+	return acpi_bay_match(handle);
+}
+
+/*
+ * acpi_dock_match - see if an acpi object has a _DCK method
+ */
+bool acpi_dock_match(acpi_handle handle)
+{
+	return acpi_has_method(handle, "_DCK");
+}
+
+static acpi_status
+acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
+			  void **return_value)
+{
+	long *cap = context;
+
+	if (acpi_has_method(handle, "_BCM") &&
+	    acpi_has_method(handle, "_BCL")) {
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
+				  "support\n"));
+		*cap |= ACPI_VIDEO_BACKLIGHT;
+		/* We have backlight support, no need to scan further */
+		return AE_CTRL_TERMINATE;
+	}
+	return 0;
+}
+
+/* Returns true if the ACPI object is a video device which can be
+ * handled by video.ko.
+ * The device will get a Linux specific CID added in scan.c to
+ * identify the device as an ACPI graphics device
+ * Be aware that the graphics device may not be physically present
+ * Use acpi_video_get_capabilities() to detect general ACPI video
+ * capabilities of present cards
+ */
+long acpi_is_video_device(acpi_handle handle)
+{
+	long video_caps = 0;
+
+	/* Is this device able to support video switching ? */
+	if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
+		video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
+
+	/* Is this device able to retrieve a video ROM ? */
+	if (acpi_has_method(handle, "_ROM"))
+		video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
+
+	/* Is this device able to configure which video head to be POSTed ? */
+	if (acpi_has_method(handle, "_VPO") &&
+	    acpi_has_method(handle, "_GPD") &&
+	    acpi_has_method(handle, "_SPD"))
+		video_caps |= ACPI_VIDEO_DEVICE_POSTING;
+
+	/* Only check for backlight functionality if one of the above hit. */
+	if (video_caps)
+		acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
+				    ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
+				    &video_caps, NULL);
+
+	return video_caps;
+}
+EXPORT_SYMBOL(acpi_is_video_device);
+
+const char *acpi_device_hid(struct acpi_device *device)
+{
+	struct acpi_hardware_id *hid;
+
+	if (list_empty(&device->pnp.ids))
+		return dummy_hid;
+
+	hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
+	return hid->id;
+}
+EXPORT_SYMBOL(acpi_device_hid);
+
+static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
+{
+	struct acpi_hardware_id *id;
+
+	id = kmalloc(sizeof(*id), GFP_KERNEL);
+	if (!id)
+		return;
+
+	id->id = kstrdup_const(dev_id, GFP_KERNEL);
+	if (!id->id) {
+		kfree(id);
+		return;
+	}
+
+	list_add_tail(&id->list, &pnp->ids);
+	pnp->type.hardware_id = 1;
+}
+
+/*
+ * Old IBM workstations have a DSDT bug wherein the SMBus object
+ * lacks the SMBUS01 HID and the methods do not have the necessary "_"
+ * prefix.  Work around this.
+ */
+static bool acpi_ibm_smbus_match(acpi_handle handle)
+{
+	char node_name[ACPI_PATH_SEGMENT_LENGTH];
+	struct acpi_buffer path = { sizeof(node_name), node_name };
+
+	if (!dmi_name_in_vendors("IBM"))
+		return false;
+
+	/* Look for SMBS object */
+	if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
+	    strcmp("SMBS", path.pointer))
+		return false;
+
+	/* Does it have the necessary (but misnamed) methods? */
+	if (acpi_has_method(handle, "SBI") &&
+	    acpi_has_method(handle, "SBR") &&
+	    acpi_has_method(handle, "SBW"))
+		return true;
+
+	return false;
+}
+
+static bool acpi_object_is_system_bus(acpi_handle handle)
+{
+	acpi_handle tmp;
+
+	if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
+	    tmp == handle)
+		return true;
+	if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
+	    tmp == handle)
+		return true;
+
+	return false;
+}
+
+static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
+				int device_type)
+{
+	acpi_status status;
+	struct acpi_device_info *info;
+	struct acpi_pnp_device_id_list *cid_list;
+	int i;
+
+	switch (device_type) {
+	case ACPI_BUS_TYPE_DEVICE:
+		if (handle == ACPI_ROOT_OBJECT) {
+			acpi_add_id(pnp, ACPI_SYSTEM_HID);
+			break;
+		}
+
+		status = acpi_get_object_info(handle, &info);
+		if (ACPI_FAILURE(status)) {
+			pr_err(PREFIX "%s: Error reading device info\n",
+					__func__);
+			return;
+		}
+
+		if (info->valid & ACPI_VALID_HID) {
+			acpi_add_id(pnp, info->hardware_id.string);
+			pnp->type.platform_id = 1;
+		}
+		if (info->valid & ACPI_VALID_CID) {
+			cid_list = &info->compatible_id_list;
+			for (i = 0; i < cid_list->count; i++)
+				acpi_add_id(pnp, cid_list->ids[i].string);
+		}
+		if (info->valid & ACPI_VALID_ADR) {
+			pnp->bus_address = info->address;
+			pnp->type.bus_address = 1;
+		}
+		if (info->valid & ACPI_VALID_UID)
+			pnp->unique_id = kstrdup(info->unique_id.string,
+							GFP_KERNEL);
+		if (info->valid & ACPI_VALID_CLS)
+			acpi_add_id(pnp, info->class_code.string);
+
+		kfree(info);
+
+		/*
+		 * Some devices don't reliably have _HIDs & _CIDs, so add
+		 * synthetic HIDs to make sure drivers can find them.
+		 */
+		if (acpi_is_video_device(handle))
+			acpi_add_id(pnp, ACPI_VIDEO_HID);
+		else if (acpi_bay_match(handle))
+			acpi_add_id(pnp, ACPI_BAY_HID);
+		else if (acpi_dock_match(handle))
+			acpi_add_id(pnp, ACPI_DOCK_HID);
+		else if (acpi_ibm_smbus_match(handle))
+			acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
+		else if (list_empty(&pnp->ids) &&
+			 acpi_object_is_system_bus(handle)) {
+			/* \_SB, \_TZ, LNXSYBUS */
+			acpi_add_id(pnp, ACPI_BUS_HID);
+			strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
+			strcpy(pnp->device_class, ACPI_BUS_CLASS);
+		}
+
+		break;
+	case ACPI_BUS_TYPE_POWER:
+		acpi_add_id(pnp, ACPI_POWER_HID);
+		break;
+	case ACPI_BUS_TYPE_PROCESSOR:
+		acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
+		break;
+	case ACPI_BUS_TYPE_THERMAL:
+		acpi_add_id(pnp, ACPI_THERMAL_HID);
+		break;
+	case ACPI_BUS_TYPE_POWER_BUTTON:
+		acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
+		break;
+	case ACPI_BUS_TYPE_SLEEP_BUTTON:
+		acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
+		break;
+	case ACPI_BUS_TYPE_ECDT_EC:
+		acpi_add_id(pnp, ACPI_ECDT_HID);
+		break;
+	}
+}
+
+void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
+{
+	struct acpi_hardware_id *id, *tmp;
+
+	list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
+		kfree_const(id->id);
+		kfree(id);
+	}
+	kfree(pnp->unique_id);
+}
+
+/**
+ * acpi_dma_supported - Check DMA support for the specified device.
+ * @adev: The pointer to acpi device
+ *
+ * Return false if DMA is not supported. Otherwise, return true
+ */
+bool acpi_dma_supported(struct acpi_device *adev)
+{
+	if (!adev)
+		return false;
+
+	if (adev->flags.cca_seen)
+		return true;
+
+	/*
+	* Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent
+	* DMA on "Intel platforms".  Presumably that includes all x86 and
+	* ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y.
+	*/
+	if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
+		return true;
+
+	return false;
+}
+
+/**
+ * acpi_get_dma_attr - Check the supported DMA attr for the specified device.
+ * @adev: The pointer to acpi device
+ *
+ * Return enum dev_dma_attr.
+ */
+enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
+{
+	if (!acpi_dma_supported(adev))
+		return DEV_DMA_NOT_SUPPORTED;
+
+	if (adev->flags.coherent_dma)
+		return DEV_DMA_COHERENT;
+	else
+		return DEV_DMA_NON_COHERENT;
+}
+
+/**
+ * acpi_dma_get_range() - Get device DMA parameters.
+ *
+ * @dev: device to configure
+ * @dma_addr: pointer device DMA address result
+ * @offset: pointer to the DMA offset result
+ * @size: pointer to DMA range size result
+ *
+ * Evaluate DMA regions and return respectively DMA region start, offset
+ * and size in dma_addr, offset and size on parsing success; it does not
+ * update the passed in values on failure.
+ *
+ * Return 0 on success, < 0 on failure.
+ */
+int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,
+		       u64 *size)
+{
+	struct acpi_device *adev;
+	LIST_HEAD(list);
+	struct resource_entry *rentry;
+	int ret;
+	struct device *dma_dev = dev;
+	u64 len, dma_start = U64_MAX, dma_end = 0, dma_offset = 0;
+
+	/*
+	 * Walk the device tree chasing an ACPI companion with a _DMA
+	 * object while we go. Stop if we find a device with an ACPI
+	 * companion containing a _DMA method.
+	 */
+	do {
+		adev = ACPI_COMPANION(dma_dev);
+		if (adev && acpi_has_method(adev->handle, METHOD_NAME__DMA))
+			break;
+
+		dma_dev = dma_dev->parent;
+	} while (dma_dev);
+
+	if (!dma_dev)
+		return -ENODEV;
+
+	if (!acpi_has_method(adev->handle, METHOD_NAME__CRS)) {
+		acpi_handle_warn(adev->handle, "_DMA is valid only if _CRS is present\n");
+		return -EINVAL;
+	}
+
+	ret = acpi_dev_get_dma_resources(adev, &list);
+	if (ret > 0) {
+		list_for_each_entry(rentry, &list, node) {
+			if (dma_offset && rentry->offset != dma_offset) {
+				ret = -EINVAL;
+				dev_warn(dma_dev, "Can't handle multiple windows with different offsets\n");
+				goto out;
+			}
+			dma_offset = rentry->offset;
+
+			/* Take lower and upper limits */
+			if (rentry->res->start < dma_start)
+				dma_start = rentry->res->start;
+			if (rentry->res->end > dma_end)
+				dma_end = rentry->res->end;
+		}
+
+		if (dma_start >= dma_end) {
+			ret = -EINVAL;
+			dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
+			goto out;
+		}
+
+		*dma_addr = dma_start - dma_offset;
+		len = dma_end - dma_start;
+		*size = max(len, len + 1);
+		*offset = dma_offset;
+	}
+ out:
+	acpi_dev_free_resource_list(&list);
+
+	return ret >= 0 ? 0 : ret;
+}
+
+/**
+ * acpi_dma_configure - Set-up DMA configuration for the device.
+ * @dev: The pointer to the device
+ * @attr: device dma attributes
+ */
+int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr)
+{
+	const struct iommu_ops *iommu;
+	u64 dma_addr = 0, size = 0;
+
+	iort_dma_setup(dev, &dma_addr, &size);
+
+	iommu = iort_iommu_configure(dev);
+	if (IS_ERR(iommu) && PTR_ERR(iommu) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+
+	arch_setup_dma_ops(dev, dma_addr, size,
+				iommu, attr == DEV_DMA_COHERENT);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(acpi_dma_configure);
+
+/**
+ * acpi_dma_deconfigure - Tear-down DMA configuration for the device.
+ * @dev: The pointer to the device
+ */
+void acpi_dma_deconfigure(struct device *dev)
+{
+	arch_teardown_dma_ops(dev);
+}
+EXPORT_SYMBOL_GPL(acpi_dma_deconfigure);
+
+static void acpi_init_coherency(struct acpi_device *adev)
+{
+	unsigned long long cca = 0;
+	acpi_status status;
+	struct acpi_device *parent = adev->parent;
+
+	if (parent && parent->flags.cca_seen) {
+		/*
+		 * From ACPI spec, OSPM will ignore _CCA if an ancestor
+		 * already saw one.
+		 */
+		adev->flags.cca_seen = 1;
+		cca = parent->flags.coherent_dma;
+	} else {
+		status = acpi_evaluate_integer(adev->handle, "_CCA",
+					       NULL, &cca);
+		if (ACPI_SUCCESS(status))
+			adev->flags.cca_seen = 1;
+		else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
+			/*
+			 * If architecture does not specify that _CCA is
+			 * required for DMA-able devices (e.g. x86),
+			 * we default to _CCA=1.
+			 */
+			cca = 1;
+		else
+			acpi_handle_debug(adev->handle,
+					  "ACPI device is missing _CCA.\n");
+	}
+
+	adev->flags.coherent_dma = cca;
+}
+
+static int acpi_check_serial_bus_slave(struct acpi_resource *ares, void *data)
+{
+	bool *is_serial_bus_slave_p = data;
+
+	if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
+		return 1;
+
+	*is_serial_bus_slave_p = true;
+
+	 /* no need to do more checking */
+	return -1;
+}
+
+static bool acpi_is_indirect_io_slave(struct acpi_device *device)
+{
+	struct acpi_device *parent = device->parent;
+	static const struct acpi_device_id indirect_io_hosts[] = {
+		{"HISI0191", 0},
+		{}
+	};
+
+	return parent && !acpi_match_device_ids(parent, indirect_io_hosts);
+}
+
+static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
+{
+	struct list_head resource_list;
+	bool is_serial_bus_slave = false;
+	/*
+	 * These devices have multiple I2cSerialBus resources and an i2c-client
+	 * must be instantiated for each, each with its own i2c_device_id.
+	 * Normally we only instantiate an i2c-client for the first resource,
+	 * using the ACPI HID as id. These special cases are handled by the
+	 * drivers/platform/x86/i2c-multi-instantiate.c driver, which knows
+	 * which i2c_device_id to use for each resource.
+	 */
+	static const struct acpi_device_id i2c_multi_instantiate_ids[] = {
+		{"BSG1160", },
+		{"INT33FE", },
+		{}
+	};
+
+	if (acpi_is_indirect_io_slave(device))
+		return true;
+
+	/* Macs use device properties in lieu of _CRS resources */
+	if (x86_apple_machine &&
+	    (fwnode_property_present(&device->fwnode, "spiSclkPeriod") ||
+	     fwnode_property_present(&device->fwnode, "i2cAddress") ||
+	     fwnode_property_present(&device->fwnode, "baud")))
+		return true;
+
+	/* Instantiate a pdev for the i2c-multi-instantiate drv to bind to */
+	if (!acpi_match_device_ids(device, i2c_multi_instantiate_ids))
+		return false;
+
+	INIT_LIST_HEAD(&resource_list);
+	acpi_dev_get_resources(device, &resource_list,
+			       acpi_check_serial_bus_slave,
+			       &is_serial_bus_slave);
+	acpi_dev_free_resource_list(&resource_list);
+
+	return is_serial_bus_slave;
+}
+
+void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
+			     int type, unsigned long long sta)
+{
+	INIT_LIST_HEAD(&device->pnp.ids);
+	device->device_type = type;
+	device->handle = handle;
+	device->parent = acpi_bus_get_parent(handle);
+	device->fwnode.ops = &acpi_device_fwnode_ops;
+	acpi_set_device_status(device, sta);
+	acpi_device_get_busid(device);
+	acpi_set_pnp_ids(handle, &device->pnp, type);
+	acpi_init_properties(device);
+	acpi_bus_get_flags(device);
+	device->flags.match_driver = false;
+	device->flags.initialized = true;
+	device->flags.enumeration_by_parent =
+		acpi_device_enumeration_by_parent(device);
+	acpi_device_clear_enumerated(device);
+	device_initialize(&device->dev);
+	dev_set_uevent_suppress(&device->dev, true);
+	acpi_init_coherency(device);
+	/* Assume there are unmet deps until acpi_device_dep_initialize() runs */
+	device->dep_unmet = 1;
+}
+
+void acpi_device_add_finalize(struct acpi_device *device)
+{
+	dev_set_uevent_suppress(&device->dev, false);
+	kobject_uevent(&device->dev.kobj, KOBJ_ADD);
+}
+
+static int acpi_add_single_object(struct acpi_device **child,
+				  acpi_handle handle, int type,
+				  unsigned long long sta)
+{
+	int result;
+	struct acpi_device *device;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+
+	device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
+	if (!device) {
+		printk(KERN_ERR PREFIX "Memory allocation error\n");
+		return -ENOMEM;
+	}
+
+	acpi_init_device_object(device, handle, type, sta);
+	/*
+	 * For ACPI_BUS_TYPE_DEVICE getting the status is delayed till here so
+	 * that we can call acpi_bus_get_status() and use its quirk handling.
+	 * Note this must be done before the get power-/wakeup_dev-flags calls.
+	 */
+	if (type == ACPI_BUS_TYPE_DEVICE)
+		if (acpi_bus_get_status(device) < 0)
+			acpi_set_device_status(device, 0);
+
+	acpi_bus_get_power_flags(device);
+	acpi_bus_get_wakeup_device_flags(device);
+
+	result = acpi_device_add(device, acpi_device_release);
+	if (result) {
+		acpi_device_release(&device->dev);
+		return result;
+	}
+
+	acpi_power_add_remove_device(device, true);
+	acpi_device_add_finalize(device);
+	acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
+		dev_name(&device->dev), (char *) buffer.pointer,
+		device->parent ? dev_name(&device->parent->dev) : "(null)"));
+	kfree(buffer.pointer);
+	*child = device;
+	return 0;
+}
+
+static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
+					    void *context)
+{
+	struct resource *res = context;
+
+	if (acpi_dev_resource_memory(ares, res))
+		return AE_CTRL_TERMINATE;
+
+	return AE_OK;
+}
+
+static bool acpi_device_should_be_hidden(acpi_handle handle)
+{
+	acpi_status status;
+	struct resource res;
+
+	/* Check if it should ignore the UART device */
+	if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
+		return false;
+
+	/*
+	 * The UART device described in SPCR table is assumed to have only one
+	 * memory resource present. So we only look for the first one here.
+	 */
+	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
+				     acpi_get_resource_memory, &res);
+	if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
+		return false;
+
+	acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
+			 &res.start);
+
+	return true;
+}
+
+static int acpi_bus_type_and_status(acpi_handle handle, int *type,
+				    unsigned long long *sta)
+{
+	acpi_status status;
+	acpi_object_type acpi_type;
+
+	status = acpi_get_type(handle, &acpi_type);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	switch (acpi_type) {
+	case ACPI_TYPE_ANY:		/* for ACPI_ROOT_OBJECT */
+	case ACPI_TYPE_DEVICE:
+		if (acpi_device_should_be_hidden(handle))
+			return -ENODEV;
+
+		*type = ACPI_BUS_TYPE_DEVICE;
+		/*
+		 * acpi_add_single_object updates this once we've an acpi_device
+		 * so that acpi_bus_get_status' quirk handling can be used.
+		 */
+		*sta = ACPI_STA_DEFAULT;
+		break;
+	case ACPI_TYPE_PROCESSOR:
+		*type = ACPI_BUS_TYPE_PROCESSOR;
+		status = acpi_bus_get_status_handle(handle, sta);
+		if (ACPI_FAILURE(status))
+			return -ENODEV;
+		break;
+	case ACPI_TYPE_THERMAL:
+		*type = ACPI_BUS_TYPE_THERMAL;
+		*sta = ACPI_STA_DEFAULT;
+		break;
+	case ACPI_TYPE_POWER:
+		*type = ACPI_BUS_TYPE_POWER;
+		*sta = ACPI_STA_DEFAULT;
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+bool acpi_device_is_present(const struct acpi_device *adev)
+{
+	return adev->status.present || adev->status.functional;
+}
+
+static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
+				       const char *idstr,
+				       const struct acpi_device_id **matchid)
+{
+	const struct acpi_device_id *devid;
+
+	if (handler->match)
+		return handler->match(idstr, matchid);
+
+	for (devid = handler->ids; devid->id[0]; devid++)
+		if (!strcmp((char *)devid->id, idstr)) {
+			if (matchid)
+				*matchid = devid;
+
+			return true;
+		}
+
+	return false;
+}
+
+static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
+					const struct acpi_device_id **matchid)
+{
+	struct acpi_scan_handler *handler;
+
+	list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
+		if (acpi_scan_handler_matching(handler, idstr, matchid))
+			return handler;
+
+	return NULL;
+}
+
+void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
+{
+	if (!!hotplug->enabled == !!val)
+		return;
+
+	mutex_lock(&acpi_scan_lock);
+
+	hotplug->enabled = val;
+
+	mutex_unlock(&acpi_scan_lock);
+}
+
+static void acpi_scan_init_hotplug(struct acpi_device *adev)
+{
+	struct acpi_hardware_id *hwid;
+
+	if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
+		acpi_dock_add(adev);
+		return;
+	}
+	list_for_each_entry(hwid, &adev->pnp.ids, list) {
+		struct acpi_scan_handler *handler;
+
+		handler = acpi_scan_match_handler(hwid->id, NULL);
+		if (handler) {
+			adev->flags.hotplug_notify = true;
+			break;
+		}
+	}
+}
+
+static void acpi_device_dep_initialize(struct acpi_device *adev)
+{
+	struct acpi_dep_data *dep;
+	struct acpi_handle_list dep_devices;
+	acpi_status status;
+	int i;
+
+	adev->dep_unmet = 0;
+
+	if (!acpi_has_method(adev->handle, "_DEP"))
+		return;
+
+	status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
+					&dep_devices);
+	if (ACPI_FAILURE(status)) {
+		dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
+		return;
+	}
+
+	for (i = 0; i < dep_devices.count; i++) {
+		struct acpi_device_info *info;
+		int skip;
+
+		status = acpi_get_object_info(dep_devices.handles[i], &info);
+		if (ACPI_FAILURE(status)) {
+			dev_dbg(&adev->dev, "Error reading _DEP device info\n");
+			continue;
+		}
+
+		/*
+		 * Skip the dependency of Windows System Power
+		 * Management Controller
+		 */
+		skip = info->valid & ACPI_VALID_HID &&
+			!strcmp(info->hardware_id.string, "INT3396");
+
+		kfree(info);
+
+		if (skip)
+			continue;
+
+		dep = kzalloc(sizeof(struct acpi_dep_data), GFP_KERNEL);
+		if (!dep)
+			return;
+
+		dep->master = dep_devices.handles[i];
+		dep->slave  = adev->handle;
+		adev->dep_unmet++;
+
+		mutex_lock(&acpi_dep_list_lock);
+		list_add_tail(&dep->node , &acpi_dep_list);
+		mutex_unlock(&acpi_dep_list_lock);
+	}
+}
+
+static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
+				      void *not_used, void **return_value)
+{
+	struct acpi_device *device = NULL;
+	int type;
+	unsigned long long sta;
+	int result;
+
+	acpi_bus_get_device(handle, &device);
+	if (device)
+		goto out;
+
+	result = acpi_bus_type_and_status(handle, &type, &sta);
+	if (result)
+		return AE_OK;
+
+	if (type == ACPI_BUS_TYPE_POWER) {
+		acpi_add_power_resource(handle);
+		return AE_OK;
+	}
+
+	acpi_add_single_object(&device, handle, type, sta);
+	if (!device)
+		return AE_CTRL_DEPTH;
+
+	acpi_scan_init_hotplug(device);
+	acpi_device_dep_initialize(device);
+
+ out:
+	if (!*return_value)
+		*return_value = device;
+
+	return AE_OK;
+}
+
+static void acpi_default_enumeration(struct acpi_device *device)
+{
+	/*
+	 * Do not enumerate devices with enumeration_by_parent flag set as
+	 * they will be enumerated by their respective parents.
+	 */
+	if (!device->flags.enumeration_by_parent) {
+		acpi_create_platform_device(device, NULL);
+		acpi_device_set_enumerated(device);
+	} else {
+		blocking_notifier_call_chain(&acpi_reconfig_chain,
+					     ACPI_RECONFIG_DEVICE_ADD, device);
+	}
+}
+
+static const struct acpi_device_id generic_device_ids[] = {
+	{ACPI_DT_NAMESPACE_HID, },
+	{"", },
+};
+
+static int acpi_generic_device_attach(struct acpi_device *adev,
+				      const struct acpi_device_id *not_used)
+{
+	/*
+	 * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
+	 * below can be unconditional.
+	 */
+	if (adev->data.of_compatible)
+		acpi_default_enumeration(adev);
+
+	return 1;
+}
+
+static struct acpi_scan_handler generic_device_handler = {
+	.ids = generic_device_ids,
+	.attach = acpi_generic_device_attach,
+};
+
+static int acpi_scan_attach_handler(struct acpi_device *device)
+{
+	struct acpi_hardware_id *hwid;
+	int ret = 0;
+
+	list_for_each_entry(hwid, &device->pnp.ids, list) {
+		const struct acpi_device_id *devid;
+		struct acpi_scan_handler *handler;
+
+		handler = acpi_scan_match_handler(hwid->id, &devid);
+		if (handler) {
+			if (!handler->attach) {
+				device->pnp.type.platform_id = 0;
+				continue;
+			}
+			device->handler = handler;
+			ret = handler->attach(device, devid);
+			if (ret > 0)
+				break;
+
+			device->handler = NULL;
+			if (ret < 0)
+				break;
+		}
+	}
+
+	return ret;
+}
+
+static void acpi_bus_attach(struct acpi_device *device)
+{
+	struct acpi_device *child;
+	acpi_handle ejd;
+	int ret;
+
+	if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
+		register_dock_dependent_device(device, ejd);
+
+	acpi_bus_get_status(device);
+	/* Skip devices that are not present. */
+	if (!acpi_device_is_present(device)) {
+		device->flags.initialized = false;
+		acpi_device_clear_enumerated(device);
+		device->flags.power_manageable = 0;
+		return;
+	}
+	if (device->handler)
+		goto ok;
+
+	if (!device->flags.initialized) {
+		device->flags.power_manageable =
+			device->power.states[ACPI_STATE_D0].flags.valid;
+		if (acpi_bus_init_power(device))
+			device->flags.power_manageable = 0;
+
+		device->flags.initialized = true;
+	} else if (device->flags.visited) {
+		goto ok;
+	}
+
+	ret = acpi_scan_attach_handler(device);
+	if (ret < 0)
+		return;
+
+	device->flags.match_driver = true;
+	if (ret > 0 && !device->flags.enumeration_by_parent) {
+		acpi_device_set_enumerated(device);
+		goto ok;
+	}
+
+	ret = device_attach(&device->dev);
+	if (ret < 0)
+		return;
+
+	if (device->pnp.type.platform_id || device->flags.enumeration_by_parent)
+		acpi_default_enumeration(device);
+	else
+		acpi_device_set_enumerated(device);
+
+ ok:
+	list_for_each_entry(child, &device->children, node)
+		acpi_bus_attach(child);
+
+	if (device->handler && device->handler->hotplug.notify_online)
+		device->handler->hotplug.notify_online(device);
+}
+
+void acpi_walk_dep_device_list(acpi_handle handle)
+{
+	struct acpi_dep_data *dep, *tmp;
+	struct acpi_device *adev;
+
+	mutex_lock(&acpi_dep_list_lock);
+	list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
+		if (dep->master == handle) {
+			acpi_bus_get_device(dep->slave, &adev);
+			if (!adev)
+				continue;
+
+			adev->dep_unmet--;
+			if (!adev->dep_unmet)
+				acpi_bus_attach(adev);
+			list_del(&dep->node);
+			kfree(dep);
+		}
+	}
+	mutex_unlock(&acpi_dep_list_lock);
+}
+EXPORT_SYMBOL_GPL(acpi_walk_dep_device_list);
+
+/**
+ * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
+ * @handle: Root of the namespace scope to scan.
+ *
+ * Scan a given ACPI tree (probably recently hot-plugged) and create and add
+ * found devices.
+ *
+ * If no devices were found, -ENODEV is returned, but it does not mean that
+ * there has been a real error.  There just have been no suitable ACPI objects
+ * in the table trunk from which the kernel could create a device and add an
+ * appropriate driver.
+ *
+ * Must be called under acpi_scan_lock.
+ */
+int acpi_bus_scan(acpi_handle handle)
+{
+	void *device = NULL;
+
+	if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
+		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
+				    acpi_bus_check_add, NULL, NULL, &device);
+
+	if (device) {
+		acpi_bus_attach(device);
+		return 0;
+	}
+	return -ENODEV;
+}
+EXPORT_SYMBOL(acpi_bus_scan);
+
+/**
+ * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
+ * @adev: Root of the ACPI namespace scope to walk.
+ *
+ * Must be called under acpi_scan_lock.
+ */
+void acpi_bus_trim(struct acpi_device *adev)
+{
+	struct acpi_scan_handler *handler = adev->handler;
+	struct acpi_device *child;
+
+	list_for_each_entry_reverse(child, &adev->children, node)
+		acpi_bus_trim(child);
+
+	adev->flags.match_driver = false;
+	if (handler) {
+		if (handler->detach)
+			handler->detach(adev);
+
+		adev->handler = NULL;
+	} else {
+		device_release_driver(&adev->dev);
+	}
+	/*
+	 * Most likely, the device is going away, so put it into D3cold before
+	 * that.
+	 */
+	acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
+	adev->flags.initialized = false;
+	acpi_device_clear_enumerated(adev);
+}
+EXPORT_SYMBOL_GPL(acpi_bus_trim);
+
+int acpi_bus_register_early_device(int type)
+{
+	struct acpi_device *device = NULL;
+	int result;
+
+	result = acpi_add_single_object(&device, NULL,
+					type, ACPI_STA_DEFAULT);
+	if (result)
+		return result;
+
+	device->flags.match_driver = true;
+	return device_attach(&device->dev);
+}
+EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);
+
+static int acpi_bus_scan_fixed(void)
+{
+	int result = 0;
+
+	/*
+	 * Enumerate all fixed-feature devices.
+	 */
+	if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
+		struct acpi_device *device = NULL;
+
+		result = acpi_add_single_object(&device, NULL,
+						ACPI_BUS_TYPE_POWER_BUTTON,
+						ACPI_STA_DEFAULT);
+		if (result)
+			return result;
+
+		device->flags.match_driver = true;
+		result = device_attach(&device->dev);
+		if (result < 0)
+			return result;
+
+		device_init_wakeup(&device->dev, true);
+	}
+
+	if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
+		struct acpi_device *device = NULL;
+
+		result = acpi_add_single_object(&device, NULL,
+						ACPI_BUS_TYPE_SLEEP_BUTTON,
+						ACPI_STA_DEFAULT);
+		if (result)
+			return result;
+
+		device->flags.match_driver = true;
+		result = device_attach(&device->dev);
+	}
+
+	return result < 0 ? result : 0;
+}
+
+static void __init acpi_get_spcr_uart_addr(void)
+{
+	acpi_status status;
+	struct acpi_table_spcr *spcr_ptr;
+
+	status = acpi_get_table(ACPI_SIG_SPCR, 0,
+				(struct acpi_table_header **)&spcr_ptr);
+	if (ACPI_SUCCESS(status))
+		spcr_uart_addr = spcr_ptr->serial_port.address;
+	else
+		printk(KERN_WARNING PREFIX "STAO table present, but SPCR is missing\n");
+}
+
+static bool acpi_scan_initialized;
+
+int __init acpi_scan_init(void)
+{
+	int result;
+	acpi_status status;
+	struct acpi_table_stao *stao_ptr;
+
+	acpi_pci_root_init();
+	acpi_pci_link_init();
+	acpi_processor_init();
+	acpi_lpss_init();
+	acpi_apd_init();
+	acpi_cmos_rtc_init();
+	acpi_container_init();
+	acpi_memory_hotplug_init();
+	acpi_watchdog_init();
+	acpi_pnp_init();
+	acpi_int340x_thermal_init();
+	acpi_amba_init();
+	acpi_init_lpit();
+
+	acpi_scan_add_handler(&generic_device_handler);
+
+	/*
+	 * If there is STAO table, check whether it needs to ignore the UART
+	 * device in SPCR table.
+	 */
+	status = acpi_get_table(ACPI_SIG_STAO, 0,
+				(struct acpi_table_header **)&stao_ptr);
+	if (ACPI_SUCCESS(status)) {
+		if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
+			printk(KERN_INFO PREFIX "STAO Name List not yet supported.");
+
+		if (stao_ptr->ignore_uart)
+			acpi_get_spcr_uart_addr();
+	}
+
+	acpi_gpe_apply_masked_gpes();
+	acpi_update_all_gpes();
+
+	mutex_lock(&acpi_scan_lock);
+	/*
+	 * Enumerate devices in the ACPI namespace.
+	 */
+	result = acpi_bus_scan(ACPI_ROOT_OBJECT);
+	if (result)
+		goto out;
+
+	result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
+	if (result)
+		goto out;
+
+	/* Fixed feature devices do not exist on HW-reduced platform */
+	if (!acpi_gbl_reduced_hardware) {
+		result = acpi_bus_scan_fixed();
+		if (result) {
+			acpi_detach_data(acpi_root->handle,
+					 acpi_scan_drop_device);
+			acpi_device_del(acpi_root);
+			put_device(&acpi_root->dev);
+			goto out;
+		}
+	}
+
+	acpi_scan_initialized = true;
+
+ out:
+	mutex_unlock(&acpi_scan_lock);
+	return result;
+}
+
+static struct acpi_probe_entry *ape;
+static int acpi_probe_count;
+static DEFINE_MUTEX(acpi_probe_mutex);
+
+static int __init acpi_match_madt(struct acpi_subtable_header *header,
+				  const unsigned long end)
+{
+	if (!ape->subtable_valid || ape->subtable_valid(header, ape))
+		if (!ape->probe_subtbl(header, end))
+			acpi_probe_count++;
+
+	return 0;
+}
+
+int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
+{
+	int count = 0;
+
+	if (acpi_disabled)
+		return 0;
+
+	mutex_lock(&acpi_probe_mutex);
+	for (ape = ap_head; nr; ape++, nr--) {
+		if (ACPI_COMPARE_NAME(ACPI_SIG_MADT, ape->id)) {
+			acpi_probe_count = 0;
+			acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
+			count += acpi_probe_count;
+		} else {
+			int res;
+			res = acpi_table_parse(ape->id, ape->probe_table);
+			if (!res)
+				count++;
+		}
+	}
+	mutex_unlock(&acpi_probe_mutex);
+
+	return count;
+}
+
+struct acpi_table_events_work {
+	struct work_struct work;
+	void *table;
+	u32 event;
+};
+
+static void acpi_table_events_fn(struct work_struct *work)
+{
+	struct acpi_table_events_work *tew;
+
+	tew = container_of(work, struct acpi_table_events_work, work);
+
+	if (tew->event == ACPI_TABLE_EVENT_LOAD) {
+		acpi_scan_lock_acquire();
+		acpi_bus_scan(ACPI_ROOT_OBJECT);
+		acpi_scan_lock_release();
+	}
+
+	kfree(tew);
+}
+
+void acpi_scan_table_handler(u32 event, void *table, void *context)
+{
+	struct acpi_table_events_work *tew;
+
+	if (!acpi_scan_initialized)
+		return;
+
+	if (event != ACPI_TABLE_EVENT_LOAD)
+		return;
+
+	tew = kmalloc(sizeof(*tew), GFP_KERNEL);
+	if (!tew)
+		return;
+
+	INIT_WORK(&tew->work, acpi_table_events_fn);
+	tew->table = table;
+	tew->event = event;
+
+	schedule_work(&tew->work);
+}
+
+int acpi_reconfig_notifier_register(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&acpi_reconfig_chain, nb);
+}
+EXPORT_SYMBOL(acpi_reconfig_notifier_register);
+
+int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&acpi_reconfig_chain, nb);
+}
+EXPORT_SYMBOL(acpi_reconfig_notifier_unregister);