/******************************************************************************
*
* Module Name: tbutils - Table manipulation utilities
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2005, R. Byron Moore
* 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 ("tbutils")
/*******************************************************************************
*
* FUNCTION: acpi_tb_handle_to_object
*
* PARAMETERS: table_id - Id for which the function is searching
* table_desc - Pointer to return the matching table
* descriptor.
*
* RETURN: Search the tables to find one with a matching table_id and
* return a pointer to that table descriptor.
*
******************************************************************************/
#ifdef ACPI_FUTURE_USAGE
acpi_status
acpi_tb_handle_to_object (
u16 table_id,
struct acpi_table_desc **return_table_desc)
{
u32 i;
struct acpi_table_desc *table_desc;
ACPI_FUNCTION_NAME ("tb_handle_to_object");
for (i = 0; i < ACPI_TABLE_MAX; i++) {
table_desc = acpi_gbl_table_lists[i].next;
while (table_desc) {
if (table_desc->table_id == table_id) {
*return_table_desc = table_desc;
return (AE_OK);
}
table_desc = table_desc->next;
}
}
ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "table_id=%X does not exist\n", table_id));
return (AE_BAD_PARAMETER);
}
#endif /* ACPI_FUTURE_USAGE */
/*******************************************************************************
*
* FUNCTION: acpi_tb_validate_table_header
*
* PARAMETERS: table_header - Logical pointer to the table
*
* RETURN: Status
*
* DESCRIPTION: Check an ACPI table header for validity
*
* NOTE: Table pointers are validated as follows:
* 1) Table pointer must point to valid physical memory
* 2) Signature must be 4 ASCII chars, even if we don't recognize the
* name
* 3) Table must be readable for length specified in the header
* 4) Table checksum must be valid (with the exception of the FACS
* which has no checksum because it contains variable fields)
*
******************************************************************************/
acpi_status
acpi_tb_validate_table_header (
struct acpi_table_header *table_header)
{
acpi_name signature;
ACPI_FUNCTION_NAME ("tb_validate_table_header");
/* Verify that this is a valid address */
if (!acpi_os_readable (table_header, sizeof (struct acpi_table_header))) {
ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
"Cannot read table header at %p\n", table_header));
return (AE_BAD_ADDRESS);
}
/* Ensure that the signature is 4 ASCII characters */
ACPI_MOVE_32_TO_32 (&signature, table_header->signature);
if (!acpi_ut_valid_acpi_name (signature)) {
ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
"Table signature at %p [%p] has invalid characters\n",
table_header, &signature));
ACPI_REPORT_WARNING (("Invalid table signature found: [%4.4s]\n",
(char *) &signature));
ACPI_DUMP_BUFFER (table_header, sizeof (struct acpi_table_header));
return (AE_BAD_SIGNATURE);
}
/* Validate the table length */
if (table_header->length < sizeof (struct acpi_table_header)) {
ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
"Invalid length in table header %p name %4.4s\n",
table_header, (char *) &signature));
ACPI_REPORT_WARNING (("Invalid table header length (0x%X) found\n",
(u32) table_header->length));
ACPI_DUMP_BUFFER (table_header, sizeof (struct acpi_table_header));
return (AE_BAD_HEADER);
}
return (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_tb_verify_table_checksum
*
* PARAMETERS: *table_header - ACPI table to verify
*
* RETURN: 8 bit checksum of table
*
* DESCRIPTION: Does an 8 bit checksum of table and returns status. A correct
* table should have a checksum of 0.
*
******************************************************************************/
acpi_status
acpi_tb_verify_table_checksum (
struct acpi_table_header *table_header)
{
u8 checksum;
acpi_status status = AE_OK;
ACPI_FUNCTION_TRACE ("tb_verify_table_checksum");
/* Compute the checksum on the table */
checksum = acpi_tb_checksum (table_header, table_header->length);
/* Return the appropriate exception */
if (checksum) {
ACPI_REPORT_WARNING (("Invalid checksum in table [%4.4s] (%02X, sum %02X is not zero)\n",
table_header->signature, (u32) table_header->checksum, (u32) checksum));
status = AE_BAD_CHECKSUM;
}
return_ACPI_STATUS (status);
}
/*******************************************************************************
*
* FUNCTION: acpi_tb_checksum
*
* PARAMETERS: Buffer - Buffer to checksum
* Length - Size of the buffer
*
* RETURNS 8 bit checksum of buffer
*
* DESCRIPTION: Computes an 8 bit checksum of the buffer(length) and returns it.
*
******************************************************************************/
u8
acpi_tb_checksum (
void *buffer,
u32 length)
{
const u8 *limit;
const u8 *rover;
u8 sum = 0;
if (buffer && length) {
/* Buffer and Length are valid */
limit = (u8 *) buffer + length;
for (rover = buffer; rover < limit; rover++) {
sum = (u8) (sum + *rover);
}
}
return (sum);
}
