1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
  2/******************************************************************************
  3 *
  4 * Module Name: tbfind   - find table
  5 *
  6 * Copyright (C) 2000 - 2023, Intel Corp.
  7 *
  8 *****************************************************************************/
  9
 10#include <acpi/acpi.h>
 11#include "accommon.h"
 12#include "actables.h"
 13
 14#define _COMPONENT          ACPI_TABLES
 15ACPI_MODULE_NAME("tbfind")
 16
 17/*******************************************************************************
 18 *
 19 * FUNCTION:    acpi_tb_find_table
 20 *
 21 * PARAMETERS:  signature           - String with ACPI table signature
 22 *              oem_id              - String with the table OEM ID
 23 *              oem_table_id        - String with the OEM Table ID
 24 *              table_index         - Where the table index is returned
 25 *
 26 * RETURN:      Status and table index
 27 *
 28 * DESCRIPTION: Find an ACPI table (in the RSDT/XSDT) that matches the
 29 *              Signature, OEM ID and OEM Table ID. Returns an index that can
 30 *              be used to get the table header or entire table.
 31 *
 32 ******************************************************************************/
 33acpi_status
 34acpi_tb_find_table(char *signature,
 35		   char *oem_id, char *oem_table_id, u32 *table_index)
 36{
 37	acpi_status status = AE_OK;
 38	struct acpi_table_header header;
 39	u32 i;
 40
 41	ACPI_FUNCTION_TRACE(tb_find_table);
 42
 43	/* Validate the input table signature */
 44
 45	if (!acpi_ut_valid_nameseg(signature)) {
 46		return_ACPI_STATUS(AE_BAD_SIGNATURE);
 47	}
 48
 49	/* Don't allow the OEM strings to be too long */
 50
 51	if ((strlen(oem_id) > ACPI_OEM_ID_SIZE) ||
 52	    (strlen(oem_table_id) > ACPI_OEM_TABLE_ID_SIZE)) {
 53		return_ACPI_STATUS(AE_AML_STRING_LIMIT);
 54	}
 55
 56	/* Normalize the input strings */
 57
 58	memset(&header, 0, sizeof(struct acpi_table_header));
 59	ACPI_COPY_NAMESEG(header.signature, signature);
 60	strncpy(header.oem_id, oem_id, ACPI_OEM_ID_SIZE);
 61	strncpy(header.oem_table_id, oem_table_id, ACPI_OEM_TABLE_ID_SIZE);
 62
 63	/* Search for the table */
 64
 65	(void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 66	for (i = 0; i < acpi_gbl_root_table_list.current_table_count; ++i) {
 67		if (memcmp(&(acpi_gbl_root_table_list.tables[i].signature),
 68			   header.signature, ACPI_NAMESEG_SIZE)) {
 69
 70			/* Not the requested table */
 71
 72			continue;
 73		}
 74
 75		/* Table with matching signature has been found */
 76
 77		if (!acpi_gbl_root_table_list.tables[i].pointer) {
 78
 79			/* Table is not currently mapped, map it */
 80
 81			status =
 82			    acpi_tb_validate_table(&acpi_gbl_root_table_list.
 83						   tables[i]);
 84			if (ACPI_FAILURE(status)) {
 85				goto unlock_and_exit;
 86			}
 87
 88			if (!acpi_gbl_root_table_list.tables[i].pointer) {
 89				continue;
 90			}
 91		}
 92
 93		/* Check for table match on all IDs */
 94
 95		if (!memcmp
 96		    (acpi_gbl_root_table_list.tables[i].pointer->signature,
 97		     header.signature, ACPI_NAMESEG_SIZE) && (!oem_id[0]
 98							      ||
 99							      !memcmp
100							      (acpi_gbl_root_table_list.
101							       tables[i].
102							       pointer->oem_id,
103							       header.oem_id,
104							       ACPI_OEM_ID_SIZE))
105		    && (!oem_table_id[0]
106			|| !memcmp(acpi_gbl_root_table_list.tables[i].pointer->
107				   oem_table_id, header.oem_table_id,
108				   ACPI_OEM_TABLE_ID_SIZE))) {
109			*table_index = i;
110
111			ACPI_DEBUG_PRINT((ACPI_DB_TABLES,
112					  "Found table [%4.4s]\n",
113					  header.signature));
114			goto unlock_and_exit;
115		}
116	}
117	status = AE_NOT_FOUND;
118
119unlock_and_exit:
120	(void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
121	return_ACPI_STATUS(status);
122}