drivers/acpi/tables/tbfind.c

/******************************************************************************
 *
 * Module Name: tbfind   - find table
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2008, 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 <acpi/actables.h>

#define _COMPONENT          ACPI_TABLES
ACPI_MODULE_NAME("tbfind")

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_find_table
 *
 * PARAMETERS:  Signature           - String with ACPI table signature
 *              oem_id              - String with the table OEM ID
 *              oem_table_id        - String with the OEM Table ID
 *              table_index         - Where the table index is returned
 *
 * RETURN:      Status and table index
 *
 * DESCRIPTION: Find an ACPI table (in the RSDT/XSDT) that matches the
 *              Signature, OEM ID and OEM Table ID. Returns an index that can
 *              be used to get the table header or entire table.
 *
 ******************************************************************************/
acpi_status
acpi_tb_find_table(char *signature,
		   char *oem_id, char *oem_table_id, u32 *table_index)
{
	u32 i;
	acpi_status status;
	struct acpi_table_header header;

	ACPI_FUNCTION_TRACE(tb_find_table);

	/* Normalize the input strings */

	ACPI_MEMSET(&header, 0, sizeof(struct acpi_table_header));
	ACPI_STRNCPY(header.signature, signature, ACPI_NAME_SIZE);
	ACPI_STRNCPY(header.oem_id, oem_id, ACPI_OEM_ID_SIZE);
	ACPI_STRNCPY(header.oem_table_id, oem_table_id, ACPI_OEM_TABLE_ID_SIZE);

	/* Search for the table */

	for (i = 0; i < acpi_gbl_root_table_list.count; ++i) {
		if (ACPI_MEMCMP(&(acpi_gbl_root_table_list.tables[i].signature),
				header.signature, ACPI_NAME_SIZE)) {

			/* Not the requested table */

			continue;
		}

		/* Table with matching signature has been found */

		if (!acpi_gbl_root_table_list.tables[i].pointer) {

			/* Table is not currently mapped, map it */

			status =
			    acpi_tb_verify_table(&acpi_gbl_root_table_list.
						 tables[i]);
			if (ACPI_FAILURE(status)) {
				return_ACPI_STATUS(status);
			}

			if (!acpi_gbl_root_table_list.tables[i].pointer) {
				continue;
			}
		}

		/* Check for table match on all IDs */

		if (!ACPI_MEMCMP
		    (acpi_gbl_root_table_list.tables[i].pointer->signature,
		     header.signature, ACPI_NAME_SIZE) && (!oem_id[0]
							   ||
							   !ACPI_MEMCMP
							   (acpi_gbl_root_table_list.
							    tables[i].pointer->
							    oem_id,
							    header.oem_id,
							    ACPI_OEM_ID_SIZE))
		    && (!oem_table_id[0]
			|| !ACPI_MEMCMP(acpi_gbl_root_table_list.tables[i].
					pointer->oem_table_id,
					header.oem_table_id,
					ACPI_OEM_TABLE_ID_SIZE))) {
			*table_index = i;

			ACPI_DEBUG_PRINT((ACPI_DB_TABLES,
					  "Found table [%4.4s]\n",
					  header.signature));
			return_ACPI_STATUS(AE_OK);
		}
	}

	return_ACPI_STATUS(AE_NOT_FOUND);
}