drivers/acpi/utils.c - linux/kernel/git/gregkh/char-misc - Git at Google

 /*
  *  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.
  *
  *  You should have received a copy of the GNU General Public License along
  *  with this program; if not, write to the Free Software Foundation, Inc.,
  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/types.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>

 #define _COMPONENT		ACPI_BUS_COMPONENT
 ACPI_MODULE_NAME("acpi_utils")

 /* --------------------------------------------------------------------------
                             Object Evaluation Helpers
    -------------------------------------------------------------------------- */
 #ifdef ACPI_DEBUG_OUTPUT
 #define acpi_util_eval_error(h,p,s) {\
 	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
 #define acpi_util_eval_error(h,p,s)
 #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;

 	ACPI_FUNCTION_TRACE("acpi_extract_package");

 	if (!package || (package->type != ACPI_TYPE_PACKAGE)
 	    || (package->package.count < 1)) {
 		ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 				  "Invalid 'package' argument\n"));
 		return_ACPI_STATUS(AE_BAD_PARAMETER);
 	}

 	if (!format || !format->pointer || (format->length < 1)) {
 		ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid 'format' argument\n"));
 		return_ACPI_STATUS(AE_BAD_PARAMETER);
 	}

 	if (!buffer) {
 		ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid 'buffer' argument\n"));
 		return_ACPI_STATUS(AE_BAD_PARAMETER);
 	}

 	format_count = (format->length / sizeof(char)) - 1;
 	if (format_count > package->package.count) {
 		ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 				  "Format specifies more objects [%d] than exist in package [%d].",
 				  format_count, package->package.count));
 		return_ACPI_STATUS(AE_BAD_DATA);
 	}

 	format_string = (char *)format->pointer;

 	/*
 	 * Calculate size_required.
 	 */
 	for (i = 0; i < format_count; i++) {

 		union acpi_object *element = &(package->package.elements[i]);

 		if (!element) {
 			return_ACPI_STATUS(AE_BAD_DATA);
 		}

 		switch (element->type) {

 		case ACPI_TYPE_INTEGER:
 			switch (format_string[i]) {
 			case 'N':
 				size_required += sizeof(acpi_integer);
 				tail_offset += sizeof(acpi_integer);
 				break;
 			case 'S':
 				size_required +=
 				    sizeof(char *) + sizeof(acpi_integer) +
 				    sizeof(char);
 				tail_offset += sizeof(char *);
 				break;
 			default:
 				ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 						  "Invalid package element [%d]: got number, expecing [%c].\n",
 						  i, format_string[i]));
 				return_ACPI_STATUS(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 * sizeof(u8));
 				tail_offset += sizeof(u8 *);
 				break;
 			default:
 				ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 						  "Invalid package element [%d] got string/buffer, expecing [%c].\n",
 						  i, format_string[i]));
 				return_ACPI_STATUS(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_ACPI_STATUS(AE_SUPPORT);
 			break;
 		}
 	}

 	/*
 	 * Validate output buffer.
 	 */
 	if (buffer->length < size_required) {
 		buffer->length = size_required;
 		return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
 	} else if (buffer->length != size_required || !buffer->pointer) {
 		return_ACPI_STATUS(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]);

 		if (!element) {
 			return_ACPI_STATUS(AE_BAD_DATA);
 		}

 		switch (element->type) {

 		case ACPI_TYPE_INTEGER:
 			switch (format_string[i]) {
 			case 'N':
 				*((acpi_integer *) head) =
 				    element->integer.value;
 				head += sizeof(acpi_integer);
 				break;
 			case 'S':
 				pointer = (u8 **) head;
 				*pointer = tail;
 				*((acpi_integer *) tail) =
 				    element->integer.value;
 				head += sizeof(acpi_integer *);
 				tail += sizeof(acpi_integer);
 				/* 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 * sizeof(u8);
 				break;
 			default:
 				/* Should never get here */
 				break;
 			}
 			break;

 		case ACPI_TYPE_PACKAGE:
 			/* TBD: handle nested packages... */
 		default:
 			/* Should never get here */
 			break;
 		}
 	}

 	return_ACPI_STATUS(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 *data)
 {
 	acpi_status status = AE_OK;
 	union acpi_object *element;
 	struct acpi_buffer buffer = { 0, NULL };

 	ACPI_FUNCTION_TRACE("acpi_evaluate_integer");

 	if (!data)
 		return_ACPI_STATUS(AE_BAD_PARAMETER);

 	element = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
 	if (!element)
 		return_ACPI_STATUS(AE_NO_MEMORY);

 	memset(element, 0, sizeof(union acpi_object));
 	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_ACPI_STATUS(status);
 	}

 	if (element->type != ACPI_TYPE_INTEGER) {
 		acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
 		return_ACPI_STATUS(AE_BAD_DATA);
 	}

 	*data = element->integer.value;
 	kfree(element);

 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Return value [%lu]\n", *data));

 	return_ACPI_STATUS(AE_OK);
 }

 EXPORT_SYMBOL(acpi_evaluate_integer);

 #if 0
 acpi_status
 acpi_evaluate_string(acpi_handle handle,
 		     acpi_string pathname,
 		     acpi_object_list * arguments, acpi_string * data)
 {
 	acpi_status status = AE_OK;
 	acpi_object *element = NULL;
 	acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

 	ACPI_FUNCTION_TRACE("acpi_evaluate_string");

 	if (!data)
 		return_ACPI_STATUS(AE_BAD_PARAMETER);

 	status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
 	if (ACPI_FAILURE(status)) {
 		acpi_util_eval_error(handle, pathname, status);
 		return_ACPI_STATUS(status);
 	}

 	element = (acpi_object *) buffer.pointer;

 	if ((element->type != ACPI_TYPE_STRING)
 	    || (element->type != ACPI_TYPE_BUFFER)
 	    || !element->string.length) {
 		acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
 		return_ACPI_STATUS(AE_BAD_DATA);
 	}

 	*data = kmalloc(element->string.length + 1, GFP_KERNEL);
 	if (!data) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Memory allocation error\n"));
 		return_VALUE(-ENOMEM);
 	}
 	memset(*data, 0, element->string.length + 1);

 	memcpy(*data, element->string.pointer, element->string.length);

 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Return value [%s]\n", *data));

 	acpi_os_free(buffer.pointer);

 	return_ACPI_STATUS(AE_OK);
 }
 #endif

 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;

 	ACPI_FUNCTION_TRACE("acpi_evaluate_reference");

 	if (!list) {
 		return_ACPI_STATUS(AE_BAD_PARAMETER);
 	}

 	/* Evaluate object. */

 	status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
 	if (ACPI_FAILURE(status))
 		goto end;

 	package = (union acpi_object *)buffer.pointer;

 	if ((buffer.length == 0) || !package) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 				  "No return object (len %X ptr %p)\n",
 				  (unsigned)buffer.length, package));
 		status = AE_BAD_DATA;
 		acpi_util_eval_error(handle, pathname, status);
 		goto end;
 	}
 	if (package->type != ACPI_TYPE_PACKAGE) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 				  "Expecting a [Package], found type %X\n",
 				  package->type));
 		status = AE_BAD_DATA;
 		acpi_util_eval_error(handle, pathname, status);
 		goto end;
 	}
 	if (!package->package.count) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 				  "[Package] has zero elements (%p)\n",
 				  package));
 		status = AE_BAD_DATA;
 		acpi_util_eval_error(handle, pathname, status);
 		goto end;
 	}

 	if (package->package.count > ACPI_MAX_HANDLES) {
 		return_ACPI_STATUS(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_ANY) {
 			status = AE_BAD_DATA;
 			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 					  "Expecting a [Reference] package element, found type %X\n",
 					  element->type));
 			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);
 	}

 	acpi_os_free(buffer.pointer);

 	return_ACPI_STATUS(status);
 }

 EXPORT_SYMBOL(acpi_evaluate_reference);
	/*
	* 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.
	*
	* You should have received a copy of the GNU General Public License along
	* with this program; if not, write to the Free Software Foundation, Inc.,
	* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
	*
	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/types.h>
	#include <acpi/acpi_bus.h>
	#include <acpi/acpi_drivers.h>

	#define _COMPONENT ACPI_BUS_COMPONENT
	ACPI_MODULE_NAME("acpi_utils")

	/* --------------------------------------------------------------------------
	Object Evaluation Helpers
	-------------------------------------------------------------------------- */
	#ifdef ACPI_DEBUG_OUTPUT
	#define acpi_util_eval_error(h,p,s) {\
	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
	#define acpi_util_eval_error(h,p,s)
	#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;

	ACPI_FUNCTION_TRACE("acpi_extract_package");

	if (!package \|\| (package->type != ACPI_TYPE_PACKAGE)
	\|\| (package->package.count < 1)) {
	ACPI_DEBUG_PRINT((ACPI_DB_WARN,
	"Invalid 'package' argument\n"));
	return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	if (!format \|\| !format->pointer \|\| (format->length < 1)) {
	ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid 'format' argument\n"));
	return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	if (!buffer) {
	ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid 'buffer' argument\n"));
	return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	format_count = (format->length / sizeof(char)) - 1;
	if (format_count > package->package.count) {
	ACPI_DEBUG_PRINT((ACPI_DB_WARN,
	"Format specifies more objects [%d] than exist in package [%d].",
	format_count, package->package.count));
	return_ACPI_STATUS(AE_BAD_DATA);
	}

	format_string = (char *)format->pointer;

	/*
	* Calculate size_required.
	*/
	for (i = 0; i < format_count; i++) {

	union acpi_object *element = &(package->package.elements[i]);

	if (!element) {
	return_ACPI_STATUS(AE_BAD_DATA);
	}

	switch (element->type) {

	case ACPI_TYPE_INTEGER:
	switch (format_string[i]) {
	case 'N':
	size_required += sizeof(acpi_integer);
	tail_offset += sizeof(acpi_integer);
	break;
	case 'S':
	size_required +=
	sizeof(char *) + sizeof(acpi_integer) +
	sizeof(char);
	tail_offset += sizeof(char *);
	break;
	default:
	ACPI_DEBUG_PRINT((ACPI_DB_WARN,
	"Invalid package element [%d]: got number, expecing [%c].\n",
	i, format_string[i]));
	return_ACPI_STATUS(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 * sizeof(u8));
	tail_offset += sizeof(u8 *);
	break;
	default:
	ACPI_DEBUG_PRINT((ACPI_DB_WARN,
	"Invalid package element [%d] got string/buffer, expecing [%c].\n",
	i, format_string[i]));
	return_ACPI_STATUS(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_ACPI_STATUS(AE_SUPPORT);
	break;
	}
	}

	/*
	* Validate output buffer.
	*/
	if (buffer->length < size_required) {
	buffer->length = size_required;
	return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
	} else if (buffer->length != size_required \|\| !buffer->pointer) {
	return_ACPI_STATUS(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]);

	if (!element) {
	return_ACPI_STATUS(AE_BAD_DATA);
	}

	switch (element->type) {

	case ACPI_TYPE_INTEGER:
	switch (format_string[i]) {
	case 'N':
	((acpi_integer ) head) =
	element->integer.value;
	head += sizeof(acpi_integer);
	break;
	case 'S':
	pointer = (u8 **) head;
	*pointer = tail;
	((acpi_integer ) tail) =
	element->integer.value;
	head += sizeof(acpi_integer *);
	tail += sizeof(acpi_integer);
	/* 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 * sizeof(u8);
	break;
	default:
	/* Should never get here */
	break;
	}
	break;

	case ACPI_TYPE_PACKAGE:
	/* TBD: handle nested packages... */
	default:
	/* Should never get here */
	break;
	}
	}

	return_ACPI_STATUS(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 data)
	{
	acpi_status status = AE_OK;
	union acpi_object *element;
	struct acpi_buffer buffer = { 0, NULL };

	ACPI_FUNCTION_TRACE("acpi_evaluate_integer");

	if (!data)
	return_ACPI_STATUS(AE_BAD_PARAMETER);

	element = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
	if (!element)
	return_ACPI_STATUS(AE_NO_MEMORY);

	memset(element, 0, sizeof(union acpi_object));
	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_ACPI_STATUS(status);
	}

	if (element->type != ACPI_TYPE_INTEGER) {
	acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
	return_ACPI_STATUS(AE_BAD_DATA);
	}

	*data = element->integer.value;
	kfree(element);

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Return value [%lu]\n", *data));

	return_ACPI_STATUS(AE_OK);
	}

	EXPORT_SYMBOL(acpi_evaluate_integer);

	#if 0
	acpi_status
	acpi_evaluate_string(acpi_handle handle,
	acpi_string pathname,
	acpi_object_list * arguments, acpi_string * data)
	{
	acpi_status status = AE_OK;
	acpi_object *element = NULL;
	acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	ACPI_FUNCTION_TRACE("acpi_evaluate_string");

	if (!data)
	return_ACPI_STATUS(AE_BAD_PARAMETER);

	status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
	if (ACPI_FAILURE(status)) {
	acpi_util_eval_error(handle, pathname, status);
	return_ACPI_STATUS(status);
	}

	element = (acpi_object *) buffer.pointer;

	if ((element->type != ACPI_TYPE_STRING)
	\|\| (element->type != ACPI_TYPE_BUFFER)
	\|\| !element->string.length) {
	acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
	return_ACPI_STATUS(AE_BAD_DATA);
	}

	*data = kmalloc(element->string.length + 1, GFP_KERNEL);
	if (!data) {
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Memory allocation error\n"));
	return_VALUE(-ENOMEM);
	}
	memset(*data, 0, element->string.length + 1);

	memcpy(*data, element->string.pointer, element->string.length);

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Return value [%s]\n", *data));

	acpi_os_free(buffer.pointer);

	return_ACPI_STATUS(AE_OK);
	}
	#endif

	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;

	ACPI_FUNCTION_TRACE("acpi_evaluate_reference");

	if (!list) {
	return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	/* Evaluate object. */

	status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
	if (ACPI_FAILURE(status))
	goto end;

	package = (union acpi_object *)buffer.pointer;

	if ((buffer.length == 0) \|\| !package) {
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	"No return object (len %X ptr %p)\n",
	(unsigned)buffer.length, package));
	status = AE_BAD_DATA;
	acpi_util_eval_error(handle, pathname, status);
	goto end;
	}
	if (package->type != ACPI_TYPE_PACKAGE) {
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	"Expecting a [Package], found type %X\n",
	package->type));
	status = AE_BAD_DATA;
	acpi_util_eval_error(handle, pathname, status);
	goto end;
	}
	if (!package->package.count) {
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	"[Package] has zero elements (%p)\n",
	package));
	status = AE_BAD_DATA;
	acpi_util_eval_error(handle, pathname, status);
	goto end;
	}

	if (package->package.count > ACPI_MAX_HANDLES) {
	return_ACPI_STATUS(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_ANY) {
	status = AE_BAD_DATA;
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	"Expecting a [Reference] package element, found type %X\n",
	element->type));
	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);
	}

	acpi_os_free(buffer.pointer);

	return_ACPI_STATUS(status);
	}

	EXPORT_SYMBOL(acpi_evaluate_reference);