cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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tbfind.c (3484B)

      1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
      2/******************************************************************************
      3 *
      4 * Module Name: tbfind   - find table
      5 *
      6 * Copyright (C) 2000 - 2022, 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}