drivers/acpi/acpica/tbfind.c

   1 /******************************************************************************
   2  *
   3  * Module Name: tbfind   - find table
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2016, Intel Corp.
   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 "accommon.h"
  46 #include "actables.h"
  47
  48 #define _COMPONENT          ACPI_TABLES
  49 ACPI_MODULE_NAME("tbfind")
  50
  51 /*******************************************************************************
  52  *
  53  * FUNCTION:    acpi_tb_find_table
  54  *
  55  * PARAMETERS:  signature           - String with ACPI table signature
  56  *              oem_id              - String with the table OEM ID
  57  *              oem_table_id        - String with the OEM Table ID
  58  *              table_index         - Where the table index is returned
  59  *
  60  * RETURN:      Status and table index
  61  *
  62  * DESCRIPTION: Find an ACPI table (in the RSDT/XSDT) that matches the
  63  *              Signature, OEM ID and OEM Table ID. Returns an index that can
  64  *              be used to get the table header or entire table.
  65  *
  66  ******************************************************************************/
  67 acpi_status
  68 acpi_tb_find_table(char *signature,
  69                    char *oem_id, char *oem_table_id, u32 *table_index)
  70 {
  71         acpi_status status = AE_OK;
  72         struct acpi_table_header header;
  73         u32 i;
  74
  75         ACPI_FUNCTION_TRACE(tb_find_table);
  76
  77         /* Validate the input table signature */
  78
  79         if (!acpi_ut_valid_nameseg(signature)) {
  80                 return_ACPI_STATUS(AE_BAD_SIGNATURE);
  81         }
  82
  83         /* Don't allow the OEM strings to be too long */
  84
  85         if ((strlen(oem_id) > ACPI_OEM_ID_SIZE) ||
  86             (strlen(oem_table_id) > ACPI_OEM_TABLE_ID_SIZE)) {
  87                 return_ACPI_STATUS(AE_AML_STRING_LIMIT);
  88         }
  89
  90         /* Normalize the input strings */
  91
  92         memset(&header, 0, sizeof(struct acpi_table_header));
  93         ACPI_MOVE_NAME(header.signature, signature);
  94         strncpy(header.oem_id, oem_id, ACPI_OEM_ID_SIZE);
  95         strncpy(header.oem_table_id, oem_table_id, ACPI_OEM_TABLE_ID_SIZE);
  96
  97         /* Search for the table */
  98
  99         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 100         for (i = 0; i < acpi_gbl_root_table_list.current_table_count; ++i) {
 101                 if (memcmp(&(acpi_gbl_root_table_list.tables[i].signature),
 102                            header.signature, ACPI_NAME_SIZE)) {
 103
 104                         /* Not the requested table */
 105
 106                         continue;
 107                 }
 108
 109                 /* Table with matching signature has been found */
 110
 111                 if (!acpi_gbl_root_table_list.tables[i].pointer) {
 112
 113                         /* Table is not currently mapped, map it */
 114
 115                         status =
 116                             acpi_tb_validate_table(&acpi_gbl_root_table_list.
 117                                                    tables[i]);
 118                         if (ACPI_FAILURE(status)) {
 119                                 goto unlock_and_exit;
 120                         }
 121
 122                         if (!acpi_gbl_root_table_list.tables[i].pointer) {
 123                                 continue;
 124                         }
 125                 }
 126
 127                 /* Check for table match on all IDs */
 128
 129                 if (!memcmp
 130                     (acpi_gbl_root_table_list.tables[i].pointer->signature,
 131                      header.signature, ACPI_NAME_SIZE) && (!oem_id[0]
 132                                                            ||
 133                                                            !memcmp
 134                                                            (acpi_gbl_root_table_list.
 135                                                             tables[i].pointer->
 136                                                             oem_id,
 137                                                             header.oem_id,
 138                                                             ACPI_OEM_ID_SIZE))
 139                     && (!oem_table_id[0]
 140                         || !memcmp(acpi_gbl_root_table_list.tables[i].pointer->
 141                                    oem_table_id, header.oem_table_id,
 142                                    ACPI_OEM_TABLE_ID_SIZE))) {
 143                         *table_index = i;
 144
 145                         ACPI_DEBUG_PRINT((ACPI_DB_TABLES,
 146                                           "Found table [%4.4s]\n",
 147                                           header.signature));
 148                         goto unlock_and_exit;
 149                 }
 150         }
 151         status = AE_NOT_FOUND;
 152
 153 unlock_and_exit:
 154         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 155         return_ACPI_STATUS(status);
 156 }