// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   *  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>

   */
  
  #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
  ",
  		(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
  ");

  		return AE_BAD_PARAMETER;

  	}
  
  	if (!format || !format->pointer || (format->length < 1)) {

  		printk(KERN_WARNING PREFIX "Invalid format argument
  ");

  		return AE_BAD_PARAMETER;

  	}
  
  	if (!buffer) {

  		printk(KERN_WARNING PREFIX "Invalid buffer argument
  ");

  		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].
  ",
  			      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]
  ",
  					      i, format_string[i]);

  				return AE_BAD_DATA;

  			}
  			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]
  ",

  					      i, format_string[i]);

  				return AE_BAD_DATA;

  			}
  			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]
  ",
  					      i, format_string[i]);
  				return AE_BAD_DATA;

  			}
  			break;

  
  		case ACPI_TYPE_PACKAGE:
  		default:

  			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  					  "Found unsupported element at index=%d
  ",
  					  i));

  			/* TBD: handle nested packages... */

  			return AE_SUPPORT;

  		}
  	}
  
  	/*
  	 * 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]
  ", *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]
  ",

  				  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

   * @handle: ACPI device 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

   * @level: log level
   * @handle: ACPI device handle
   * @fmt: format string

   *
   * 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

   * @descriptor: Dynamic Debug descriptor
   * @handle: ACPI device handle
   * @fmt: format string

   *
   * 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
  ");
  	else if (ACPI_FAILURE(status))
  		acpi_handle_warn(handle, "Eject failed (0x%x)
  ", 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)
  ", status);
  		else
  			acpi_handle_warn(handle,
  				"Unlocking device failed (0x%x)
  ", status);
  	}
  
  	return status;
  }

  
  /**

   * acpi_evaluate_reg: Evaluate _REG method to register OpRegion presence
   * @handle: ACPI device handle
   * @space_id: ACPI address space id to register OpRegion presence for
   * @function: Parameter to pass to _REG one of ACPI_REG_CONNECT or
   *            ACPI_REG_DISCONNECT
   *
   * Evaluate device's _REG method to register OpRegion presence.
   */
  acpi_status acpi_evaluate_reg(acpi_handle handle, u8 space_id, u32 function)
  {
  	struct acpi_object_list arg_list;
  	union acpi_object params[2];
  
  	params[0].type = ACPI_TYPE_INTEGER;
  	params[0].integer.value = space_id;
  	params[1].type = ACPI_TYPE_INTEGER;
  	params[1].integer.value = function;
  	arg_list.count = 2;
  	arg_list.pointer = params;
  
  	return acpi_evaluate_object(handle, "_REG", &arg_list, NULL);
  }
  EXPORT_SYMBOL(acpi_evaluate_reg);
  
  /**

   * 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)
  ", 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_hid_uid_match - Match device by supplied HID and UID
   * @adev: ACPI device to match.
   * @hid2: Hardware ID of the device.
   * @uid2: Unique ID of the device, pass NULL to not check _UID.
   *
   * Matches HID and UID in @adev with given @hid2 and @uid2.
   * Returns true if matches.
   */
  bool acpi_dev_hid_uid_match(struct acpi_device *adev,
  			    const char *hid2, const char *uid2)
  {
  	const char *hid1 = acpi_device_hid(adev);
  	const char *uid1 = acpi_device_uid(adev);
  
  	if (strcmp(hid1, hid2))
  		return false;
  
  	if (!uid2)
  		return true;
  
  	return uid1 && !strcmp(uid1, uid2);
  }
  EXPORT_SYMBOL(acpi_dev_hid_uid_match);
  
  /**

   * 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 {

  	struct acpi_device_id hid[2];
  	const char *uid;
  	s64 hrv;
  };

  static int acpi_dev_match_cb(struct device *dev, const void *data)

  {
  	struct acpi_device *adev = to_acpi_device(dev);

  	const 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;
  
  	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_dev - Return the 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 the first match of ACPI device if a matching device was present

   * at the moment of invocation, or NULL otherwise.
   *

   * The caller is responsible to call put_device() on the returned device.
   *

   * See additional information in acpi_dev_present() as well.
   */

  struct acpi_device *
  acpi_dev_get_first_match_dev(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 ? to_acpi_device(dev) : NULL;

  }
  EXPORT_SYMBOL(acpi_dev_get_first_match_dev);

  /*
   * 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);