alistair23-linux/drivers/acpi/acpica/tbfind.c

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

/*
 * Copyright (C) 2000 - 2016, 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 "accommon.h"
#include "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)
{
	acpi_status status;
	struct acpi_table_header header;
	u32 i;

	ACPI_FUNCTION_TRACE(tb_find_table);

	/* Validate the input table signature */

	if (!acpi_is_valid_signature(signature)) {
		return_ACPI_STATUS(AE_BAD_SIGNATURE);
	}

	/* Don't allow the OEM strings to be too long */

	if ((strlen(oem_id) > ACPI_OEM_ID_SIZE) ||
	    (strlen(oem_table_id) > ACPI_OEM_TABLE_ID_SIZE)) {
		return_ACPI_STATUS(AE_AML_STRING_LIMIT);
	}

	/* Normalize the input strings */

	memset(&header, 0, sizeof(struct acpi_table_header));
	ACPI_MOVE_NAME(header.signature, signature);
	strncpy(header.oem_id, oem_id, ACPI_OEM_ID_SIZE);
	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.current_table_count; ++i) {
		if (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_validate_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 (!memcmp
		    (acpi_gbl_root_table_list.tables[i].pointer->signature,
		     header.signature, ACPI_NAME_SIZE) && (!oem_id[0]
							   ||
							   !memcmp
							   (acpi_gbl_root_table_list.
							    tables[i].pointer->
							    oem_id,
							    header.oem_id,
							    ACPI_OEM_ID_SIZE))
		    && (!oem_table_id[0]
			|| !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);
}