/*******************************************************************************
   *
   * Module Name: utresrc - Resource management utilities
   *
   ******************************************************************************/
  
  /*
   * Copyright (C) 2000 - 2013, 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 <acpi/acpi.h>
  #include "accommon.h"
  #include "acresrc.h"
  
  #define _COMPONENT          ACPI_UTILITIES
  ACPI_MODULE_NAME("utresrc")
  #if 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"
  };
  
  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[] = {
  	"StopBitsNone",
  	"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);
  }