linux/drivers/acpi/acpica/tbfind.c

123 lines
3.4 KiB
C

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
*
* Module Name: tbfind - find table
*
* Copyright (C) 2000 - 2019, Intel Corp.
*
*****************************************************************************/
#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 = AE_OK;
struct acpi_table_header header;
u32 i;
ACPI_FUNCTION_TRACE(tb_find_table);
/* Validate the input table signature */
if (!acpi_ut_valid_nameseg(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_COPY_NAMESEG(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 */
(void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
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_NAMESEG_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)) {
goto unlock_and_exit;
}
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_NAMESEG_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));
goto unlock_and_exit;
}
}
status = AE_NOT_FOUND;
unlock_and_exit:
(void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
return_ACPI_STATUS(status);
}