|  | /******************************************************************************* | 
|  | * | 
|  | * Module Name: utresrc - Resource managment utilities | 
|  | * | 
|  | ******************************************************************************/ | 
|  |  | 
|  | /* | 
|  | * Copyright (C) 2000 - 2006, R. Byron Moore | 
|  | * 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 <acpi/amlresrc.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 disasssembler 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" | 
|  | }; | 
|  |  | 
|  | 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" | 
|  | }; | 
|  |  | 
|  | #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), | 
|  | 0, | 
|  | 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) | 
|  | }; | 
|  |  | 
|  | /* | 
|  | * 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, | 
|  | ACPI_FIXED_LENGTH, | 
|  | ACPI_SMALL_VARIABLE_LENGTH, | 
|  | ACPI_FIXED_LENGTH, | 
|  | ACPI_FIXED_LENGTH, | 
|  | ACPI_FIXED_LENGTH, | 
|  | 0, | 
|  | 0, | 
|  | 0, | 
|  | 0, | 
|  | ACPI_VARIABLE_LENGTH, | 
|  | ACPI_FIXED_LENGTH, | 
|  |  | 
|  | /* Large descriptors */ | 
|  |  | 
|  | 0, | 
|  | ACPI_FIXED_LENGTH, | 
|  | ACPI_FIXED_LENGTH, | 
|  | 0, | 
|  | ACPI_VARIABLE_LENGTH, | 
|  | ACPI_FIXED_LENGTH, | 
|  | ACPI_FIXED_LENGTH, | 
|  | ACPI_VARIABLE_LENGTH, | 
|  | ACPI_VARIABLE_LENGTH, | 
|  | ACPI_VARIABLE_LENGTH, | 
|  | ACPI_VARIABLE_LENGTH, | 
|  | ACPI_FIXED_LENGTH | 
|  | }; | 
|  |  | 
|  | /******************************************************************************* | 
|  | * | 
|  | * FUNCTION:    acpi_ut_walk_aml_resources | 
|  | * | 
|  | * 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(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; | 
|  |  | 
|  | 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(aml, &resource_index); | 
|  | if (ACPI_FAILURE(status)) { | 
|  | 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 (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 */ | 
|  |  | 
|  | return (AE_AML_NO_RESOURCE_END_TAG); | 
|  | } | 
|  |  | 
|  | /******************************************************************************* | 
|  | * | 
|  | * FUNCTION:    acpi_ut_validate_resource | 
|  | * | 
|  | * PARAMETERS:  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(void *aml, u8 * return_index) | 
|  | { | 
|  | 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) { | 
|  | return (AE_AML_INVALID_RESOURCE_TYPE); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * 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, zero indicates name is invalid */ | 
|  |  | 
|  | if (!acpi_gbl_resource_types[resource_index]) { | 
|  | return (AE_AML_INVALID_RESOURCE_TYPE); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * 2) 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) { | 
|  | return (AE_AML_BAD_RESOURCE_LENGTH); | 
|  | } | 
|  | break; | 
|  |  | 
|  | case ACPI_VARIABLE_LENGTH: | 
|  |  | 
|  | /* Variable length resource, length must be at least the minimum */ | 
|  |  | 
|  | if (resource_length < minimum_resource_length) { | 
|  | return (AE_AML_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))) { | 
|  | return (AE_AML_BAD_RESOURCE_LENGTH); | 
|  | } | 
|  | break; | 
|  |  | 
|  | default: | 
|  |  | 
|  | /* Shouldn't happen (because of validation earlier), but be sure */ | 
|  |  | 
|  | return (AE_AML_INVALID_RESOURCE_TYPE); | 
|  | } | 
|  |  | 
|  | /* Optionally return the resource table index */ | 
|  |  | 
|  | if (return_index) { | 
|  | *return_index = resource_index; | 
|  | } | 
|  |  | 
|  | return (AE_OK); | 
|  | } | 
|  |  | 
|  | /******************************************************************************* | 
|  | * | 
|  | * 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(obj_desc->buffer.pointer, | 
|  | obj_desc->buffer.length, NULL, | 
|  | (void **)end_tag); | 
|  |  | 
|  | return_ACPI_STATUS(status); | 
|  | } |