drivers/acpi/tables/tbfind.c

   1 /******************************************************************************
   2  *
   3  * Module Name: tbfind   - find table
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2007, R. Byron Moore
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include <acpi/acpi.h>
  45 #include <acpi/actables.h>
  46
  47 #define _COMPONENT          ACPI_TABLES
  48 ACPI_MODULE_NAME("tbfind")
  49
  50 /*******************************************************************************
  51  *
  52  * FUNCTION:    acpi_tb_find_table
  53  *
  54  * PARAMETERS:  Signature           - String with ACPI table signature
  55  *              oem_id              - String with the table OEM ID
  56  *              oem_table_id        - String with the OEM Table ID
  57  *              table_index         - Where the table index is returned
  58  *
  59  * RETURN:      Status and table index
  60  *
  61  * DESCRIPTION: Find an ACPI table (in the RSDT/XSDT) that matches the
  62  *              Signature, OEM ID and OEM Table ID. Returns an index that can
  63  *              be used to get the table header or entire table.
  64  *
  65  ******************************************************************************/
  66 acpi_status
  67 acpi_tb_find_table(char *signature,
  68                    char *oem_id,
  69                    char *oem_table_id, acpi_native_uint * table_index)
  70 {
  71         acpi_native_uint i;
  72         acpi_status status;
  73
  74         ACPI_FUNCTION_TRACE(tb_find_table);
  75
  76         for (i = 0; i < acpi_gbl_root_table_list.count; ++i) {
  77                 if (ACPI_MEMCMP(&(acpi_gbl_root_table_list.tables[i].signature),
  78                                 signature, ACPI_NAME_SIZE)) {
  79
  80                         /* Not the requested table */
  81
  82                         continue;
  83                 }
  84
  85                 /* Table with matching signature has been found */
  86
  87                 if (!acpi_gbl_root_table_list.tables[i].pointer) {
  88
  89                         /* Table is not currently mapped, map it */
  90
  91                         status =
  92                             acpi_tb_verify_table(&acpi_gbl_root_table_list.
  93                                                  tables[i]);
  94                         if (ACPI_FAILURE(status)) {
  95                                 return_ACPI_STATUS(status);
  96                         }
  97
  98                         if (!acpi_gbl_root_table_list.tables[i].pointer) {
  99                                 continue;
 100                         }
 101                 }
 102
 103                 /* Check for table match on all IDs */
 104
 105                 if (!ACPI_MEMCMP
 106                     (acpi_gbl_root_table_list.tables[i].pointer->signature,
 107                      signature, ACPI_NAME_SIZE) && (!oem_id[0]
 108                                                     ||
 109                                                     !ACPI_MEMCMP
 110                                                     (acpi_gbl_root_table_list.
 111                                                      tables[i].pointer->oem_id,
 112                                                      oem_id, ACPI_OEM_ID_SIZE))
 113                     && (!oem_table_id[0]
 114                         || !ACPI_MEMCMP(acpi_gbl_root_table_list.tables[i].
 115                                         pointer->oem_table_id, oem_table_id,
 116                                         ACPI_OEM_TABLE_ID_SIZE))) {
 117                         *table_index = i;
 118
 119                         ACPI_DEBUG_PRINT((ACPI_DB_TABLES,
 120                                           "Found table [%4.4s]\n", signature));
 121                         return_ACPI_STATUS(AE_OK);
 122                 }
 123         }
 124
 125         return_ACPI_STATUS(AE_NOT_FOUND);
 126 }