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/*******************************************************************************

 *

 * Module Name: utresrc - Resource management utilities

 *

 ******************************************************************************/

/*

 * Copyright (C) 2000 - 2015, Intel Corp.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions, and the following disclaimer,

 *    without modification.

 * 2. Redistributions in binary form must reproduce at minimum a disclaimer

 *    substantially similar to the "NO WARRANTY" disclaimer below

 *    ("Disclaimer") and any redistribution must be conditioned upon

 *    including a substantially similar Disclaimer requirement for further

 *    binary redistribution.

 * 3. Neither the names of the above-listed copyright holders nor the names

 *    of any contributors may be used to endorse or promote products derived

 *    from this software without specific prior written permission.

 *

 * Alternatively, this software may be distributed under the terms of the

 * GNU General Public License ("GPL") version 2 as published by the Free

 * Software Foundation.

 *

 * NO WARRANTY

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR

 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING

 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGES.

 */

#include 

#include "accommon.h"

#include "acresrc.h"

#define _COMPONENT          ACPI_UTILITIES

ACPI_MODULE_NAME("utresrc")

#if defined(ACPI_DEBUG_OUTPUT) || defined (ACPI_DISASSEMBLER) || defined (ACPI_DEBUGGER)

/*

 * Strings used to decode resource descriptors.

 * Used by both the disassembler and the debugger resource dump routines

 */

const char *acpi_gbl_bm_decode[] = {

	"NotBusMaster",

	"BusMaster"

};

const char *acpi_gbl_config_decode[] = {

	"0 - Good Configuration",

	"1 - Acceptable Configuration",

	"2 - Suboptimal Configuration",

	"3 - ***Invalid Configuration***",

};

const char *acpi_gbl_consume_decode[] = {

	"ResourceProducer",

	"ResourceConsumer"

};

const char *acpi_gbl_dec_decode[] = {

	"PosDecode",

	"SubDecode"

};

const char *acpi_gbl_he_decode[] = {

	"Level",

	"Edge"

};

const char *acpi_gbl_io_decode[] = {

	"Decode10",

	"Decode16"

};

const char *acpi_gbl_ll_decode[] = {

	"ActiveHigh",

	"ActiveLow",

	"ActiveBoth",

	"Reserved"

};

const char *acpi_gbl_max_decode[] = {

	"MaxNotFixed",

	"MaxFixed"

};

const char *acpi_gbl_mem_decode[] = {

	"NonCacheable",

	"Cacheable",

	"WriteCombining",

	"Prefetchable"

};

const char *acpi_gbl_min_decode[] = {

	"MinNotFixed",

	"MinFixed"

};

const char *acpi_gbl_mtp_decode[] = {

	"AddressRangeMemory",

	"AddressRangeReserved",

	"AddressRangeACPI",

	"AddressRangeNVS"

};

const char *acpi_gbl_rng_decode[] = {

	"InvalidRanges",

	"NonISAOnlyRanges",

	"ISAOnlyRanges",

	"EntireRange"

};

const char *acpi_gbl_rw_decode[] = {

	"ReadOnly",

	"ReadWrite"

};

const char *acpi_gbl_shr_decode[] = {

	"Exclusive",

	"Shared",

	"ExclusiveAndWake",	/* ACPI 5.0 */

	"SharedAndWake"		/* ACPI 5.0 */

};

const char *acpi_gbl_siz_decode[] = {

	"Transfer8",

	"Transfer8_16",

	"Transfer16",

	"InvalidSize"

};

const char *acpi_gbl_trs_decode[] = {

	"DenseTranslation",

	"SparseTranslation"

};

const char *acpi_gbl_ttp_decode[] = {

	"TypeStatic",

	"TypeTranslation"

};

const char *acpi_gbl_typ_decode[] = {

	"Compatibility",

	"TypeA",

	"TypeB",

	"TypeF"

};

const char *acpi_gbl_ppc_decode[] = {

	"PullDefault",

	"PullUp",

	"PullDown",

	"PullNone"

};

const char *acpi_gbl_ior_decode[] = {

	"IoRestrictionNone",

	"IoRestrictionInputOnly",

	"IoRestrictionOutputOnly",

	"IoRestrictionNoneAndPreserve"

};

const char *acpi_gbl_dts_decode[] = {

	"Width8bit",

	"Width16bit",

	"Width32bit",

	"Width64bit",

	"Width128bit",

	"Width256bit",

};

/* GPIO connection type */

const char *acpi_gbl_ct_decode[] = {

	"Interrupt",

	"I/O"

};

/* Serial bus type */

const char *acpi_gbl_sbt_decode[] = {

	"/* UNKNOWN serial bus type */",

	"I2C",

	"SPI",

	"UART"

};

/* I2C serial bus access mode */

const char *acpi_gbl_am_decode[] = {

	"AddressingMode7Bit",

	"AddressingMode10Bit"

};

/* I2C serial bus slave mode */

const char *acpi_gbl_sm_decode[] = {

	"ControllerInitiated",

	"DeviceInitiated"

};

/* SPI serial bus wire mode */

const char *acpi_gbl_wm_decode[] = {

	"FourWireMode",

	"ThreeWireMode"

};

/* SPI serial clock phase */

const char *acpi_gbl_cph_decode[] = {

	"ClockPhaseFirst",

	"ClockPhaseSecond"

};

/* SPI serial bus clock polarity */

const char *acpi_gbl_cpo_decode[] = {

	"ClockPolarityLow",

	"ClockPolarityHigh"

};

/* SPI serial bus device polarity */

const char *acpi_gbl_dp_decode[] = {

	"PolarityLow",

	"PolarityHigh"

};

/* UART serial bus endian */

const char *acpi_gbl_ed_decode[] = {

	"LittleEndian",

	"BigEndian"

};

/* UART serial bus bits per byte */

const char *acpi_gbl_bpb_decode[] = {

	"DataBitsFive",

	"DataBitsSix",

	"DataBitsSeven",

	"DataBitsEight",

	"DataBitsNine",

	"/* UNKNOWN Bits per byte */",

	"/* UNKNOWN Bits per byte */",

	"/* UNKNOWN Bits per byte */"

};

/* UART serial bus stop bits */

const char *acpi_gbl_sb_decode[] = {

	"StopBitsZero",

	"StopBitsOne",

	"StopBitsOnePlusHalf",

	"StopBitsTwo"

};

/* UART serial bus flow control */

const char *acpi_gbl_fc_decode[] = {

	"FlowControlNone",

	"FlowControlHardware",

	"FlowControlXON",

	"/* UNKNOWN flow control keyword */"

};

/* UART serial bus parity type */

const char *acpi_gbl_pt_decode[] = {

	"ParityTypeNone",

	"ParityTypeEven",

	"ParityTypeOdd",

	"ParityTypeMark",

	"ParityTypeSpace",

	"/* UNKNOWN parity keyword */",

	"/* UNKNOWN parity keyword */",

	"/* UNKNOWN parity keyword */"

};

#endif

/*

 * Base sizes of the raw AML resource descriptors, indexed by resource type.

 * Zero indicates a reserved (and therefore invalid) resource type.

 */

const u8 acpi_gbl_resource_aml_sizes[] = {

	/* Small descriptors */

	0,

	0,

	0,

	0,

	ACPI_AML_SIZE_SMALL(struct aml_resource_irq),

	ACPI_AML_SIZE_SMALL(struct aml_resource_dma),

	ACPI_AML_SIZE_SMALL(struct aml_resource_start_dependent),

	ACPI_AML_SIZE_SMALL(struct aml_resource_end_dependent),

	ACPI_AML_SIZE_SMALL(struct aml_resource_io),

	ACPI_AML_SIZE_SMALL(struct aml_resource_fixed_io),

	ACPI_AML_SIZE_SMALL(struct aml_resource_fixed_dma),

	0,

	0,

	0,

	ACPI_AML_SIZE_SMALL(struct aml_resource_vendor_small),

	ACPI_AML_SIZE_SMALL(struct aml_resource_end_tag),

	/* Large descriptors */

	0,

	ACPI_AML_SIZE_LARGE(struct aml_resource_memory24),

	ACPI_AML_SIZE_LARGE(struct aml_resource_generic_register),

	0,

	ACPI_AML_SIZE_LARGE(struct aml_resource_vendor_large),

	ACPI_AML_SIZE_LARGE(struct aml_resource_memory32),

	ACPI_AML_SIZE_LARGE(struct aml_resource_fixed_memory32),

	ACPI_AML_SIZE_LARGE(struct aml_resource_address32),

	ACPI_AML_SIZE_LARGE(struct aml_resource_address16),

	ACPI_AML_SIZE_LARGE(struct aml_resource_extended_irq),

	ACPI_AML_SIZE_LARGE(struct aml_resource_address64),

	ACPI_AML_SIZE_LARGE(struct aml_resource_extended_address64),

	ACPI_AML_SIZE_LARGE(struct aml_resource_gpio),

	0,

	ACPI_AML_SIZE_LARGE(struct aml_resource_common_serialbus),

};

const u8 acpi_gbl_resource_aml_serial_bus_sizes[] = {

	0,

	ACPI_AML_SIZE_LARGE(struct aml_resource_i2c_serialbus),

	ACPI_AML_SIZE_LARGE(struct aml_resource_spi_serialbus),

	ACPI_AML_SIZE_LARGE(struct aml_resource_uart_serialbus),

};

/*

 * Resource types, used to validate the resource length field.

 * The length of fixed-length types must match exactly, variable

 * lengths must meet the minimum required length, etc.

 * Zero indicates a reserved (and therefore invalid) resource type.

 */

static const u8 acpi_gbl_resource_types[] = {

	/* Small descriptors */

	0,

	0,

	0,

	0,

	ACPI_SMALL_VARIABLE_LENGTH,	/* 04 IRQ */

	ACPI_FIXED_LENGTH,	/* 05 DMA */

	ACPI_SMALL_VARIABLE_LENGTH,	/* 06 start_dependent_functions */

	ACPI_FIXED_LENGTH,	/* 07 end_dependent_functions */

	ACPI_FIXED_LENGTH,	/* 08 IO */

	ACPI_FIXED_LENGTH,	/* 09 fixed_IO */

	ACPI_FIXED_LENGTH,	/* 0A fixed_DMA */

	0,

	0,

	0,

	ACPI_VARIABLE_LENGTH,	/* 0E vendor_short */

	ACPI_FIXED_LENGTH,	/* 0F end_tag */

	/* Large descriptors */

	0,

	ACPI_FIXED_LENGTH,	/* 01 Memory24 */

	ACPI_FIXED_LENGTH,	/* 02 generic_register */

	0,

	ACPI_VARIABLE_LENGTH,	/* 04 vendor_long */

	ACPI_FIXED_LENGTH,	/* 05 Memory32 */

	ACPI_FIXED_LENGTH,	/* 06 memory32_fixed */

	ACPI_VARIABLE_LENGTH,	/* 07 Dword* address */

	ACPI_VARIABLE_LENGTH,	/* 08 Word* address */

	ACPI_VARIABLE_LENGTH,	/* 09 extended_IRQ */

	ACPI_VARIABLE_LENGTH,	/* 0A Qword* address */

	ACPI_FIXED_LENGTH,	/* 0B Extended* address */

	ACPI_VARIABLE_LENGTH,	/* 0C Gpio* */

	0,

	ACPI_VARIABLE_LENGTH	/* 0E *serial_bus */

};

/*******************************************************************************

 *

 * FUNCTION:    acpi_ut_walk_aml_resources

 *

 * PARAMETERS:  walk_state          - Current walk info

 * PARAMETERS:  aml                 - Pointer to the raw AML resource template

 *              aml_length          - Length of the entire template

 *              user_function       - Called once for each descriptor found. If

 *                                    NULL, a pointer to the end_tag is returned

 *              context             - Passed to user_function

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Walk a raw AML resource list(buffer). User function called

 *              once for each resource found.

 *

 ******************************************************************************/

acpi_status

acpi_ut_walk_aml_resources(struct acpi_walk_state *walk_state,

			   u8 *aml,

			   acpi_size aml_length,

			   acpi_walk_aml_callback user_function, void **context)

{

	acpi_status status;

	u8 *end_aml;

	u8 resource_index;

	u32 length;

	u32 offset = 0;

	u8 end_tag[2] = { 0x79, 0x00 };

	ACPI_FUNCTION_TRACE(ut_walk_aml_resources);

	/* The absolute minimum resource template is one end_tag descriptor */

	if (aml_length < sizeof(struct aml_resource_end_tag)) {

		return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);

	}

	/* Point to the end of the resource template buffer */

	end_aml = aml + aml_length;

	/* Walk the byte list, abort on any invalid descriptor type or length */

	while (aml < end_aml) {

		/* Validate the Resource Type and Resource Length */

		status =

		    acpi_ut_validate_resource(walk_state, aml, &resource_index);

		if (ACPI_FAILURE(status)) {

			/*

			 * Exit on failure. Cannot continue because the descriptor length

			 * may be bogus also.

			 */

			return_ACPI_STATUS(status);

		}

		/* Get the length of this descriptor */

		length = acpi_ut_get_descriptor_length(aml);

		/* Invoke the user function */

		if (user_function) {

			status =

			    user_function(aml, length, offset, resource_index,

					  context);

			if (ACPI_FAILURE(status)) {

				return_ACPI_STATUS(status);

			}

		}

		/* An end_tag descriptor terminates this resource template */

		if (acpi_ut_get_resource_type(aml) ==

		    ACPI_RESOURCE_NAME_END_TAG) {

			/*

			 * There must be at least one more byte in the buffer for

			 * the 2nd byte of the end_tag

			 */

			if ((aml + 1) >= end_aml) {

				return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);

			}

			/* Return the pointer to the end_tag if requested */

			if (!user_function) {

				*context = aml;

			}

			/* Normal exit */

			return_ACPI_STATUS(AE_OK);

		}

		aml += length;

		offset += length;

	}

	/* Did not find an end_tag descriptor */

	if (user_function) {

		/* Insert an end_tag anyway. acpi_rs_get_list_length always leaves room */

		(void)acpi_ut_validate_resource(walk_state, end_tag,

						&resource_index);

		status =

		    user_function(end_tag, 2, offset, resource_index, context);

		if (ACPI_FAILURE(status)) {

			return_ACPI_STATUS(status);

		}

	}

	return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_ut_validate_resource

 *

 * PARAMETERS:  walk_state          - Current walk info

 *              aml                 - Pointer to the raw AML resource descriptor

 *              return_index        - Where the resource index is returned. NULL

 *                                    if the index is not required.

 *

 * RETURN:      Status, and optionally the Index into the global resource tables

 *

 * DESCRIPTION: Validate an AML resource descriptor by checking the Resource

 *              Type and Resource Length. Returns an index into the global

 *              resource information/dispatch tables for later use.

 *

 ******************************************************************************/

acpi_status

acpi_ut_validate_resource(struct acpi_walk_state *walk_state,

			  void *aml, u8 *return_index)

{

	union aml_resource *aml_resource;

	u8 resource_type;

	u8 resource_index;

	acpi_rs_length resource_length;

	acpi_rs_length minimum_resource_length;

	ACPI_FUNCTION_ENTRY();

	/*

	 * 1) Validate the resource_type field (Byte 0)

	 */

	resource_type = ACPI_GET8(aml);

	/*

	 * Byte 0 contains the descriptor name (Resource Type)

	 * Examine the large/small bit in the resource header

	 */

	if (resource_type & ACPI_RESOURCE_NAME_LARGE) {

		/* Verify the large resource type (name) against the max */

		if (resource_type > ACPI_RESOURCE_NAME_LARGE_MAX) {

			goto invalid_resource;

		}

		/*

		 * Large Resource Type -- bits 6:0 contain the name

		 * Translate range 0x80-0x8B to index range 0x10-0x1B

		 */

		resource_index = (u8) (resource_type - 0x70);

	} else {

		/*

		 * Small Resource Type -- bits 6:3 contain the name

		 * Shift range to index range 0x00-0x0F

		 */

		resource_index = (u8)

		    ((resource_type & ACPI_RESOURCE_NAME_SMALL_MASK) >> 3);

	}

	/*

	 * Check validity of the resource type, via acpi_gbl_resource_types. Zero

	 * indicates an invalid resource.

	 */

	if (!acpi_gbl_resource_types[resource_index]) {

		goto invalid_resource;

	}

	/*

	 * Validate the resource_length field. This ensures that the length

	 * is at least reasonable, and guarantees that it is non-zero.

	 */

	resource_length = acpi_ut_get_resource_length(aml);

	minimum_resource_length = acpi_gbl_resource_aml_sizes[resource_index];

	/* Validate based upon the type of resource - fixed length or variable */

	switch (acpi_gbl_resource_types[resource_index]) {

	case ACPI_FIXED_LENGTH:

		/* Fixed length resource, length must match exactly */

		if (resource_length != minimum_resource_length) {

			goto bad_resource_length;

		}

		break;

	case ACPI_VARIABLE_LENGTH:

		/* Variable length resource, length must be at least the minimum */

		if (resource_length < minimum_resource_length) {

			goto bad_resource_length;

		}

		break;

	case ACPI_SMALL_VARIABLE_LENGTH:

		/* Small variable length resource, length can be (Min) or (Min-1) */

		if ((resource_length > minimum_resource_length) ||

		    (resource_length < (minimum_resource_length - 1))) {

			goto bad_resource_length;

		}

		break;

	default:

		/* Shouldn't happen (because of validation earlier), but be sure */

		goto invalid_resource;

	}

	aml_resource = ACPI_CAST_PTR(union aml_resource, aml);

	if (resource_type == ACPI_RESOURCE_NAME_SERIAL_BUS) {

		/* Validate the bus_type field */

		if ((aml_resource->common_serial_bus.type == 0) ||

		    (aml_resource->common_serial_bus.type >

		     AML_RESOURCE_MAX_SERIALBUSTYPE)) {

			if (walk_state) {

				ACPI_ERROR((AE_INFO,

					    "Invalid/unsupported SerialBus resource descriptor: BusType 0x%2.2X",

					    aml_resource->common_serial_bus.

					    type));

			}

			return (AE_AML_INVALID_RESOURCE_TYPE);

		}

	}

	/* Optionally return the resource table index */

	if (return_index) {

		*return_index = resource_index;

	}

	return (AE_OK);

invalid_resource:

	if (walk_state) {

		ACPI_ERROR((AE_INFO,

			    "Invalid/unsupported resource descriptor: Type 0x%2.2X",

			    resource_type));

	}

	return (AE_AML_INVALID_RESOURCE_TYPE);

bad_resource_length:

	if (walk_state) {

		ACPI_ERROR((AE_INFO,

			    "Invalid resource descriptor length: Type "

			    "0x%2.2X, Length 0x%4.4X, MinLength 0x%4.4X",

			    resource_type, resource_length,

			    minimum_resource_length));

	}

	return (AE_AML_BAD_RESOURCE_LENGTH);

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_ut_get_resource_type

 *

 * PARAMETERS:  aml             - Pointer to the raw AML resource descriptor

 *

 * RETURN:      The Resource Type with no extraneous bits (except the

 *              Large/Small descriptor bit -- this is left alone)

 *

 * DESCRIPTION: Extract the Resource Type/Name from the first byte of

 *              a resource descriptor.

 *

 ******************************************************************************/

u8 acpi_ut_get_resource_type(void *aml)

{

	ACPI_FUNCTION_ENTRY();

	/*

	 * Byte 0 contains the descriptor name (Resource Type)

	 * Examine the large/small bit in the resource header

	 */

	if (ACPI_GET8(aml) & ACPI_RESOURCE_NAME_LARGE) {

		/* Large Resource Type -- bits 6:0 contain the name */

		return (ACPI_GET8(aml));

	} else {

		/* Small Resource Type -- bits 6:3 contain the name */

		return ((u8) (ACPI_GET8(aml) & ACPI_RESOURCE_NAME_SMALL_MASK));

	}

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_ut_get_resource_length

 *

 * PARAMETERS:  aml             - Pointer to the raw AML resource descriptor

 *

 * RETURN:      Byte Length

 *

 * DESCRIPTION: Get the "Resource Length" of a raw AML descriptor. By

 *              definition, this does not include the size of the descriptor

 *              header or the length field itself.

 *

 ******************************************************************************/

u16 acpi_ut_get_resource_length(void *aml)

{

	acpi_rs_length resource_length;

	ACPI_FUNCTION_ENTRY();

	/*

	 * Byte 0 contains the descriptor name (Resource Type)

	 * Examine the large/small bit in the resource header

	 */

	if (ACPI_GET8(aml) & ACPI_RESOURCE_NAME_LARGE) {

		/* Large Resource type -- bytes 1-2 contain the 16-bit length */

		ACPI_MOVE_16_TO_16(&resource_length, ACPI_ADD_PTR(u8, aml, 1));

	} else {

		/* Small Resource type -- bits 2:0 of byte 0 contain the length */

		resource_length = (u16) (ACPI_GET8(aml) &

					 ACPI_RESOURCE_NAME_SMALL_LENGTH_MASK);

	}

	return (resource_length);

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_ut_get_resource_header_length

 *

 * PARAMETERS:  aml             - Pointer to the raw AML resource descriptor

 *

 * RETURN:      Length of the AML header (depends on large/small descriptor)

 *

 * DESCRIPTION: Get the length of the header for this resource.

 *

 ******************************************************************************/

u8 acpi_ut_get_resource_header_length(void *aml)

{

	ACPI_FUNCTION_ENTRY();

	/* Examine the large/small bit in the resource header */

	if (ACPI_GET8(aml) & ACPI_RESOURCE_NAME_LARGE) {

		return (sizeof(struct aml_resource_large_header));

	} else {

		return (sizeof(struct aml_resource_small_header));

	}

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_ut_get_descriptor_length

 *

 * PARAMETERS:  aml             - Pointer to the raw AML resource descriptor

 *

 * RETURN:      Byte length

 *

 * DESCRIPTION: Get the total byte length of a raw AML descriptor, including the

 *              length of the descriptor header and the length field itself.

 *              Used to walk descriptor lists.

 *

 ******************************************************************************/

u32 acpi_ut_get_descriptor_length(void *aml)

{

	ACPI_FUNCTION_ENTRY();

	/*

	 * Get the Resource Length (does not include header length) and add

	 * the header length (depends on if this is a small or large resource)

	 */

	return (acpi_ut_get_resource_length(aml) +

		acpi_ut_get_resource_header_length(aml));

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_ut_get_resource_end_tag

 *

 * PARAMETERS:  obj_desc        - The resource template buffer object

 *              end_tag         - Where the pointer to the end_tag is returned

 *

 * RETURN:      Status, pointer to the end tag

 *

 * DESCRIPTION: Find the end_tag resource descriptor in an AML resource template

 *              Note: allows a buffer length of zero.

 *

 ******************************************************************************/

acpi_status

acpi_ut_get_resource_end_tag(union acpi_operand_object *obj_desc, u8 **end_tag)

{

	acpi_status status;

	ACPI_FUNCTION_TRACE(ut_get_resource_end_tag);

	/* Allow a buffer length of zero */

	if (!obj_desc->buffer.length) {

		*end_tag = obj_desc->buffer.pointer;

		return_ACPI_STATUS(AE_OK);

	}

	/* Validate the template and get a pointer to the end_tag */

	status = acpi_ut_walk_aml_resources(NULL, obj_desc->buffer.pointer,

					    obj_desc->buffer.length, NULL,

					    (void **)end_tag);

	return_ACPI_STATUS(status);

}