diff options
Diffstat (limited to 'drivers/acpi/tables/tbutils.c')
-rw-r--r-- | drivers/acpi/tables/tbutils.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/drivers/acpi/tables/tbutils.c b/drivers/acpi/tables/tbutils.c new file mode 100644 index 00000000000..fede5804c78 --- /dev/null +++ b/drivers/acpi/tables/tbutils.c @@ -0,0 +1,240 @@ +/****************************************************************************** + * + * 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); +} + + |