Adding upstream version 4.19.249.upstream/4.19.249

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

1 files changed, 883 insertions, 0 deletions

diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
new file mode 100644
index 000000000..c4b06cc07
--- /dev/null
+++ b/drivers/acpi/utils.c
@@ -0,0 +1,883 @@
+/*
+ *  acpi_utils.c - ACPI Utility Functions ($Revision: 10 $)
+ *
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/hardirq.h>
+#include <linux/acpi.h>
+#include <linux/dynamic_debug.h>
+
+#include "internal.h"
+#include "sleep.h"
+
+#define _COMPONENT		ACPI_BUS_COMPONENT
+ACPI_MODULE_NAME("utils");
+
+/* --------------------------------------------------------------------------
+                            Object Evaluation Helpers
+   -------------------------------------------------------------------------- */
+static void
+acpi_util_eval_error(acpi_handle h, acpi_string p, acpi_status s)
+{
+#ifdef ACPI_DEBUG_OUTPUT
+	char prefix[80] = {'\0'};
+	struct acpi_buffer buffer = {sizeof(prefix), prefix};
+	acpi_get_name(h, ACPI_FULL_PATHNAME, &buffer);
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluate [%s.%s]: %s\n",
+		(char *) prefix, p, acpi_format_exception(s)));
+#else
+	return;
+#endif
+}
+
+acpi_status
+acpi_extract_package(union acpi_object *package,
+		     struct acpi_buffer *format, struct acpi_buffer *buffer)
+{
+	u32 size_required = 0;
+	u32 tail_offset = 0;
+	char *format_string = NULL;
+	u32 format_count = 0;
+	u32 i = 0;
+	u8 *head = NULL;
+	u8 *tail = NULL;
+
+
+	if (!package || (package->type != ACPI_TYPE_PACKAGE)
+	    || (package->package.count < 1)) {
+		printk(KERN_WARNING PREFIX "Invalid package argument\n");
+		return AE_BAD_PARAMETER;
+	}
+
+	if (!format || !format->pointer || (format->length < 1)) {
+		printk(KERN_WARNING PREFIX "Invalid format argument\n");
+		return AE_BAD_PARAMETER;
+	}
+
+	if (!buffer) {
+		printk(KERN_WARNING PREFIX "Invalid buffer argument\n");
+		return AE_BAD_PARAMETER;
+	}
+
+	format_count = (format->length / sizeof(char)) - 1;
+	if (format_count > package->package.count) {
+		printk(KERN_WARNING PREFIX "Format specifies more objects [%d]"
+			      " than exist in package [%d].\n",
+			      format_count, package->package.count);
+		return AE_BAD_DATA;
+	}
+
+	format_string = format->pointer;
+
+	/*
+	 * Calculate size_required.
+	 */
+	for (i = 0; i < format_count; i++) {
+
+		union acpi_object *element = &(package->package.elements[i]);
+
+		switch (element->type) {
+
+		case ACPI_TYPE_INTEGER:
+			switch (format_string[i]) {
+			case 'N':
+				size_required += sizeof(u64);
+				tail_offset += sizeof(u64);
+				break;
+			case 'S':
+				size_required +=
+				    sizeof(char *) + sizeof(u64) +
+				    sizeof(char);
+				tail_offset += sizeof(char *);
+				break;
+			default:
+				printk(KERN_WARNING PREFIX "Invalid package element"
+					      " [%d]: got number, expecting"
+					      " [%c]\n",
+					      i, format_string[i]);
+				return AE_BAD_DATA;
+				break;
+			}
+			break;
+
+		case ACPI_TYPE_STRING:
+		case ACPI_TYPE_BUFFER:
+			switch (format_string[i]) {
+			case 'S':
+				size_required +=
+				    sizeof(char *) +
+				    (element->string.length * sizeof(char)) +
+				    sizeof(char);
+				tail_offset += sizeof(char *);
+				break;
+			case 'B':
+				size_required +=
+				    sizeof(u8 *) + element->buffer.length;
+				tail_offset += sizeof(u8 *);
+				break;
+			default:
+				printk(KERN_WARNING PREFIX "Invalid package element"
+					      " [%d] got string/buffer,"
+					      " expecting [%c]\n",
+					      i, format_string[i]);
+				return AE_BAD_DATA;
+				break;
+			}
+			break;
+		case ACPI_TYPE_LOCAL_REFERENCE:
+			switch (format_string[i]) {
+			case 'R':
+				size_required += sizeof(void *);
+				tail_offset += sizeof(void *);
+				break;
+			default:
+				printk(KERN_WARNING PREFIX "Invalid package element"
+					      " [%d] got reference,"
+					      " expecting [%c]\n",
+					      i, format_string[i]);
+				return AE_BAD_DATA;
+				break;
+			}
+			break;
+
+		case ACPI_TYPE_PACKAGE:
+		default:
+			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+					  "Found unsupported element at index=%d\n",
+					  i));
+			/* TBD: handle nested packages... */
+			return AE_SUPPORT;
+			break;
+		}
+	}
+
+	/*
+	 * Validate output buffer.
+	 */
+	if (buffer->length == ACPI_ALLOCATE_BUFFER) {
+		buffer->pointer = ACPI_ALLOCATE_ZEROED(size_required);
+		if (!buffer->pointer)
+			return AE_NO_MEMORY;
+		buffer->length = size_required;
+	} else {
+		if (buffer->length < size_required) {
+			buffer->length = size_required;
+			return AE_BUFFER_OVERFLOW;
+		} else if (buffer->length != size_required ||
+			   !buffer->pointer) {
+			return AE_BAD_PARAMETER;
+		}
+	}
+
+	head = buffer->pointer;
+	tail = buffer->pointer + tail_offset;
+
+	/*
+	 * Extract package data.
+	 */
+	for (i = 0; i < format_count; i++) {
+
+		u8 **pointer = NULL;
+		union acpi_object *element = &(package->package.elements[i]);
+
+		switch (element->type) {
+
+		case ACPI_TYPE_INTEGER:
+			switch (format_string[i]) {
+			case 'N':
+				*((u64 *) head) =
+				    element->integer.value;
+				head += sizeof(u64);
+				break;
+			case 'S':
+				pointer = (u8 **) head;
+				*pointer = tail;
+				*((u64 *) tail) =
+				    element->integer.value;
+				head += sizeof(u64 *);
+				tail += sizeof(u64);
+				/* NULL terminate string */
+				*tail = (char)0;
+				tail += sizeof(char);
+				break;
+			default:
+				/* Should never get here */
+				break;
+			}
+			break;
+
+		case ACPI_TYPE_STRING:
+		case ACPI_TYPE_BUFFER:
+			switch (format_string[i]) {
+			case 'S':
+				pointer = (u8 **) head;
+				*pointer = tail;
+				memcpy(tail, element->string.pointer,
+				       element->string.length);
+				head += sizeof(char *);
+				tail += element->string.length * sizeof(char);
+				/* NULL terminate string */
+				*tail = (char)0;
+				tail += sizeof(char);
+				break;
+			case 'B':
+				pointer = (u8 **) head;
+				*pointer = tail;
+				memcpy(tail, element->buffer.pointer,
+				       element->buffer.length);
+				head += sizeof(u8 *);
+				tail += element->buffer.length;
+				break;
+			default:
+				/* Should never get here */
+				break;
+			}
+			break;
+		case ACPI_TYPE_LOCAL_REFERENCE:
+			switch (format_string[i]) {
+			case 'R':
+				*(void **)head =
+				    (void *)element->reference.handle;
+				head += sizeof(void *);
+				break;
+			default:
+				/* Should never get here */
+				break;
+			}
+			break;
+		case ACPI_TYPE_PACKAGE:
+			/* TBD: handle nested packages... */
+		default:
+			/* Should never get here */
+			break;
+		}
+	}
+
+	return AE_OK;
+}
+
+EXPORT_SYMBOL(acpi_extract_package);
+
+acpi_status
+acpi_evaluate_integer(acpi_handle handle,
+		      acpi_string pathname,
+		      struct acpi_object_list *arguments, unsigned long long *data)
+{
+	acpi_status status = AE_OK;
+	union acpi_object element;
+	struct acpi_buffer buffer = { 0, NULL };
+
+	if (!data)
+		return AE_BAD_PARAMETER;
+
+	buffer.length = sizeof(union acpi_object);
+	buffer.pointer = &element;
+	status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
+	if (ACPI_FAILURE(status)) {
+		acpi_util_eval_error(handle, pathname, status);
+		return status;
+	}
+
+	if (element.type != ACPI_TYPE_INTEGER) {
+		acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
+		return AE_BAD_DATA;
+	}
+
+	*data = element.integer.value;
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Return value [%llu]\n", *data));
+
+	return AE_OK;
+}
+
+EXPORT_SYMBOL(acpi_evaluate_integer);
+
+acpi_status
+acpi_evaluate_reference(acpi_handle handle,
+			acpi_string pathname,
+			struct acpi_object_list *arguments,
+			struct acpi_handle_list *list)
+{
+	acpi_status status = AE_OK;
+	union acpi_object *package = NULL;
+	union acpi_object *element = NULL;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	u32 i = 0;
+
+
+	if (!list) {
+		return AE_BAD_PARAMETER;
+	}
+
+	/* Evaluate object. */
+
+	status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
+	if (ACPI_FAILURE(status))
+		goto end;
+
+	package = buffer.pointer;
+
+	if ((buffer.length == 0) || !package) {
+		status = AE_BAD_DATA;
+		acpi_util_eval_error(handle, pathname, status);
+		goto end;
+	}
+	if (package->type != ACPI_TYPE_PACKAGE) {
+		status = AE_BAD_DATA;
+		acpi_util_eval_error(handle, pathname, status);
+		goto end;
+	}
+	if (!package->package.count) {
+		status = AE_BAD_DATA;
+		acpi_util_eval_error(handle, pathname, status);
+		goto end;
+	}
+
+	if (package->package.count > ACPI_MAX_HANDLES) {
+		kfree(package);
+		return AE_NO_MEMORY;
+	}
+	list->count = package->package.count;
+
+	/* Extract package data. */
+
+	for (i = 0; i < list->count; i++) {
+
+		element = &(package->package.elements[i]);
+
+		if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
+			status = AE_BAD_DATA;
+			acpi_util_eval_error(handle, pathname, status);
+			break;
+		}
+
+		if (!element->reference.handle) {
+			status = AE_NULL_ENTRY;
+			acpi_util_eval_error(handle, pathname, status);
+			break;
+		}
+		/* Get the  acpi_handle. */
+
+		list->handles[i] = element->reference.handle;
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found reference [%p]\n",
+				  list->handles[i]));
+	}
+
+      end:
+	if (ACPI_FAILURE(status)) {
+		list->count = 0;
+		//kfree(list->handles);
+	}
+
+	kfree(buffer.pointer);
+
+	return status;
+}
+
+EXPORT_SYMBOL(acpi_evaluate_reference);
+
+acpi_status
+acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld)
+{
+	acpi_status status;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *output;
+
+	status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer);
+
+	if (ACPI_FAILURE(status))
+		return status;
+
+	output = buffer.pointer;
+
+	if (!output || output->type != ACPI_TYPE_PACKAGE
+	    || !output->package.count
+	    || output->package.elements[0].type != ACPI_TYPE_BUFFER
+	    || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) {
+		status = AE_TYPE;
+		goto out;
+	}
+
+	status = acpi_decode_pld_buffer(
+			output->package.elements[0].buffer.pointer,
+			output->package.elements[0].buffer.length,
+			pld);
+
+out:
+	kfree(buffer.pointer);
+	return status;
+}
+EXPORT_SYMBOL(acpi_get_physical_device_location);
+
+/**
+ * acpi_evaluate_ost: Evaluate _OST for hotplug operations
+ * @handle: ACPI device handle
+ * @source_event: source event code
+ * @status_code: status code
+ * @status_buf: optional detailed information (NULL if none)
+ *
+ * Evaluate _OST for hotplug operations. All ACPI hotplug handlers
+ * must call this function when evaluating _OST for hotplug operations.
+ * When the platform does not support _OST, this function has no effect.
+ */
+acpi_status
+acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,
+		  struct acpi_buffer *status_buf)
+{
+	union acpi_object params[3] = {
+		{.type = ACPI_TYPE_INTEGER,},
+		{.type = ACPI_TYPE_INTEGER,},
+		{.type = ACPI_TYPE_BUFFER,}
+	};
+	struct acpi_object_list arg_list = {3, params};
+
+	params[0].integer.value = source_event;
+	params[1].integer.value = status_code;
+	if (status_buf != NULL) {
+		params[2].buffer.pointer = status_buf->pointer;
+		params[2].buffer.length = status_buf->length;
+	} else {
+		params[2].buffer.pointer = NULL;
+		params[2].buffer.length = 0;
+	}
+
+	return acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
+}
+EXPORT_SYMBOL(acpi_evaluate_ost);
+
+/**
+ * acpi_handle_path: Return the object path of handle
+ *
+ * Caller must free the returned buffer
+ */
+static char *acpi_handle_path(acpi_handle handle)
+{
+	struct acpi_buffer buffer = {
+		.length = ACPI_ALLOCATE_BUFFER,
+		.pointer = NULL
+	};
+
+	if (in_interrupt() ||
+	    acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)
+		return NULL;
+	return buffer.pointer;
+}
+
+/**
+ * acpi_handle_printk: Print message with ACPI prefix and object path
+ *
+ * This function is called through acpi_handle_<level> macros and prints
+ * a message with ACPI prefix and object path.  This function acquires
+ * the global namespace mutex to obtain an object path.  In interrupt
+ * context, it shows the object path as <n/a>.
+ */
+void
+acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+	const char *path;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	path = acpi_handle_path(handle);
+	printk("%sACPI: %s: %pV", level, path ? path : "<n/a>" , &vaf);
+
+	va_end(args);
+	kfree(path);
+}
+EXPORT_SYMBOL(acpi_handle_printk);
+
+#if defined(CONFIG_DYNAMIC_DEBUG)
+/**
+ * __acpi_handle_debug: pr_debug with ACPI prefix and object path
+ *
+ * This function is called through acpi_handle_debug macro and debug
+ * prints a message with ACPI prefix and object path. This function
+ * acquires the global namespace mutex to obtain an object path.  In
+ * interrupt context, it shows the object path as <n/a>.
+ */
+void
+__acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle,
+		    const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+	const char *path;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	path = acpi_handle_path(handle);
+	__dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf);
+
+	va_end(args);
+	kfree(path);
+}
+EXPORT_SYMBOL(__acpi_handle_debug);
+#endif
+
+/**
+ * acpi_has_method: Check whether @handle has a method named @name
+ * @handle: ACPI device handle
+ * @name: name of object or method
+ *
+ * Check whether @handle has a method named @name.
+ */
+bool acpi_has_method(acpi_handle handle, char *name)
+{
+	acpi_handle tmp;
+
+	return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp));
+}
+EXPORT_SYMBOL(acpi_has_method);
+
+acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
+				       u64 arg)
+{
+	union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
+	struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, };
+
+	obj.integer.value = arg;
+
+	return acpi_evaluate_object(handle, method, &arg_list, NULL);
+}
+EXPORT_SYMBOL(acpi_execute_simple_method);
+
+/**
+ * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations
+ * @handle: ACPI device handle
+ *
+ * Evaluate device's _EJ0 method for hotplug operations.
+ */
+acpi_status acpi_evaluate_ej0(acpi_handle handle)
+{
+	acpi_status status;
+
+	status = acpi_execute_simple_method(handle, "_EJ0", 1);
+	if (status == AE_NOT_FOUND)
+		acpi_handle_warn(handle, "No _EJ0 support for device\n");
+	else if (ACPI_FAILURE(status))
+		acpi_handle_warn(handle, "Eject failed (0x%x)\n", status);
+
+	return status;
+}
+
+/**
+ * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device
+ * @handle: ACPI device handle
+ * @lock: lock device if non-zero, otherwise unlock device
+ *
+ * Evaluate device's _LCK method if present to lock/unlock device
+ */
+acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
+{
+	acpi_status status;
+
+	status = acpi_execute_simple_method(handle, "_LCK", !!lock);
+	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+		if (lock)
+			acpi_handle_warn(handle,
+				"Locking device failed (0x%x)\n", status);
+		else
+			acpi_handle_warn(handle,
+				"Unlocking device failed (0x%x)\n", status);
+	}
+
+	return status;
+}
+
+/**
+ * acpi_evaluate_dsm - evaluate device's _DSM method
+ * @handle: ACPI device handle
+ * @guid: GUID of requested functions, should be 16 bytes
+ * @rev: revision number of requested function
+ * @func: requested function number
+ * @argv4: the function specific parameter
+ *
+ * Evaluate device's _DSM method with specified GUID, revision id and
+ * function number. Caller needs to free the returned object.
+ *
+ * Though ACPI defines the fourth parameter for _DSM should be a package,
+ * some old BIOSes do expect a buffer or an integer etc.
+ */
+union acpi_object *
+acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 func,
+		  union acpi_object *argv4)
+{
+	acpi_status ret;
+	struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
+	union acpi_object params[4];
+	struct acpi_object_list input = {
+		.count = 4,
+		.pointer = params,
+	};
+
+	params[0].type = ACPI_TYPE_BUFFER;
+	params[0].buffer.length = 16;
+	params[0].buffer.pointer = (u8 *)guid;
+	params[1].type = ACPI_TYPE_INTEGER;
+	params[1].integer.value = rev;
+	params[2].type = ACPI_TYPE_INTEGER;
+	params[2].integer.value = func;
+	if (argv4) {
+		params[3] = *argv4;
+	} else {
+		params[3].type = ACPI_TYPE_PACKAGE;
+		params[3].package.count = 0;
+		params[3].package.elements = NULL;
+	}
+
+	ret = acpi_evaluate_object(handle, "_DSM", &input, &buf);
+	if (ACPI_SUCCESS(ret))
+		return (union acpi_object *)buf.pointer;
+
+	if (ret != AE_NOT_FOUND)
+		acpi_handle_warn(handle,
+				"failed to evaluate _DSM (0x%x)\n", ret);
+
+	return NULL;
+}
+EXPORT_SYMBOL(acpi_evaluate_dsm);
+
+/**
+ * acpi_check_dsm - check if _DSM method supports requested functions.
+ * @handle: ACPI device handle
+ * @guid: GUID of requested functions, should be 16 bytes at least
+ * @rev: revision number of requested functions
+ * @funcs: bitmap of requested functions
+ *
+ * Evaluate device's _DSM method to check whether it supports requested
+ * functions. Currently only support 64 functions at maximum, should be
+ * enough for now.
+ */
+bool acpi_check_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 funcs)
+{
+	int i;
+	u64 mask = 0;
+	union acpi_object *obj;
+
+	if (funcs == 0)
+		return false;
+
+	obj = acpi_evaluate_dsm(handle, guid, rev, 0, NULL);
+	if (!obj)
+		return false;
+
+	/* For compatibility, old BIOSes may return an integer */
+	if (obj->type == ACPI_TYPE_INTEGER)
+		mask = obj->integer.value;
+	else if (obj->type == ACPI_TYPE_BUFFER)
+		for (i = 0; i < obj->buffer.length && i < 8; i++)
+			mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
+	ACPI_FREE(obj);
+
+	/*
+	 * Bit 0 indicates whether there's support for any functions other than
+	 * function 0 for the specified GUID and revision.
+	 */
+	if ((mask & 0x1) && (mask & funcs) == funcs)
+		return true;
+
+	return false;
+}
+EXPORT_SYMBOL(acpi_check_dsm);
+
+/**
+ * acpi_dev_found - Detect presence of a given ACPI device in the namespace.
+ * @hid: Hardware ID of the device.
+ *
+ * Return %true if the device was present at the moment of invocation.
+ * Note that if the device is pluggable, it may since have disappeared.
+ *
+ * For this function to work, acpi_bus_scan() must have been executed
+ * which happens in the subsys_initcall() subsection. Hence, do not
+ * call from a subsys_initcall() or earlier (use acpi_get_devices()
+ * instead). Calling from module_init() is fine (which is synonymous
+ * with device_initcall()).
+ */
+bool acpi_dev_found(const char *hid)
+{
+	struct acpi_device_bus_id *acpi_device_bus_id;
+	bool found = false;
+
+	mutex_lock(&acpi_device_lock);
+	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
+		if (!strcmp(acpi_device_bus_id->bus_id, hid)) {
+			found = true;
+			break;
+		}
+	mutex_unlock(&acpi_device_lock);
+
+	return found;
+}
+EXPORT_SYMBOL(acpi_dev_found);
+
+struct acpi_dev_match_info {
+	const char *dev_name;
+	struct acpi_device_id hid[2];
+	const char *uid;
+	s64 hrv;
+};
+
+static int acpi_dev_match_cb(struct device *dev, void *data)
+{
+	struct acpi_device *adev = to_acpi_device(dev);
+	struct acpi_dev_match_info *match = data;
+	unsigned long long hrv;
+	acpi_status status;
+
+	if (acpi_match_device_ids(adev, match->hid))
+		return 0;
+
+	if (match->uid && (!adev->pnp.unique_id ||
+	    strcmp(adev->pnp.unique_id, match->uid)))
+		return 0;
+
+	match->dev_name = acpi_dev_name(adev);
+
+	if (match->hrv == -1)
+		return 1;
+
+	status = acpi_evaluate_integer(adev->handle, "_HRV", NULL, &hrv);
+	if (ACPI_FAILURE(status))
+		return 0;
+
+	return hrv == match->hrv;
+}
+
+/**
+ * acpi_dev_present - Detect that a given ACPI device is present
+ * @hid: Hardware ID of the device.
+ * @uid: Unique ID of the device, pass NULL to not check _UID
+ * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
+ *
+ * Return %true if a matching device was present at the moment of invocation.
+ * Note that if the device is pluggable, it may since have disappeared.
+ *
+ * Note that unlike acpi_dev_found() this function checks the status
+ * of the device. So for devices which are present in the dsdt, but
+ * which are disabled (their _STA callback returns 0) this function
+ * will return false.
+ *
+ * For this function to work, acpi_bus_scan() must have been executed
+ * which happens in the subsys_initcall() subsection. Hence, do not
+ * call from a subsys_initcall() or earlier (use acpi_get_devices()
+ * instead). Calling from module_init() is fine (which is synonymous
+ * with device_initcall()).
+ */
+bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
+{
+	struct acpi_dev_match_info match = {};
+	struct device *dev;
+
+	strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
+	match.uid = uid;
+	match.hrv = hrv;
+
+	dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
+	put_device(dev);
+	return !!dev;
+}
+EXPORT_SYMBOL(acpi_dev_present);
+
+/**
+ * acpi_dev_get_first_match_name - Return name of first match of ACPI device
+ * @hid: Hardware ID of the device.
+ * @uid: Unique ID of the device, pass NULL to not check _UID
+ * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
+ *
+ * Return device name if a matching device was present
+ * at the moment of invocation, or NULL otherwise.
+ *
+ * See additional information in acpi_dev_present() as well.
+ */
+const char *
+acpi_dev_get_first_match_name(const char *hid, const char *uid, s64 hrv)
+{
+	struct acpi_dev_match_info match = {};
+	struct device *dev;
+
+	strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
+	match.uid = uid;
+	match.hrv = hrv;
+
+	dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
+	return dev ? match.dev_name : NULL;
+}
+EXPORT_SYMBOL(acpi_dev_get_first_match_name);
+
+/*
+ * acpi_backlight= handling, this is done here rather then in video_detect.c
+ * because __setup cannot be used in modules.
+ */
+char acpi_video_backlight_string[16];
+EXPORT_SYMBOL(acpi_video_backlight_string);
+
+static int __init acpi_backlight(char *str)
+{
+	strlcpy(acpi_video_backlight_string, str,
+		sizeof(acpi_video_backlight_string));
+	return 1;
+}
+__setup("acpi_backlight=", acpi_backlight);
+
+/**
+ * acpi_match_platform_list - Check if the system matches with a given list
+ * @plat: pointer to acpi_platform_list table terminated by a NULL entry
+ *
+ * Return the matched index if the system is found in the platform list.
+ * Otherwise, return a negative error code.
+ */
+int acpi_match_platform_list(const struct acpi_platform_list *plat)
+{
+	struct acpi_table_header hdr;
+	int idx = 0;
+
+	if (acpi_disabled)
+		return -ENODEV;
+
+	for (; plat->oem_id[0]; plat++, idx++) {
+		if (ACPI_FAILURE(acpi_get_table_header(plat->table, 0, &hdr)))
+			continue;
+
+		if (strncmp(plat->oem_id, hdr.oem_id, ACPI_OEM_ID_SIZE))
+			continue;
+
+		if (strncmp(plat->oem_table_id, hdr.oem_table_id, ACPI_OEM_TABLE_ID_SIZE))
+			continue;
+
+		if ((plat->pred == all_versions) ||
+		    (plat->pred == less_than_or_equal && hdr.oem_revision <= plat->oem_revision) ||
+		    (plat->pred == greater_than_or_equal && hdr.oem_revision >= plat->oem_revision) ||
+		    (plat->pred == equal && hdr.oem_revision == plat->oem_revision))
+			return idx;
+	}
+
+	return -ENODEV;
+}
+EXPORT_SYMBOL(acpi_match_platform_list);