/****************************************************************************** * * Module Name: tbutils - Table manipulation utilities * *****************************************************************************/ /* * Copyright (C) 2000 - 2006, 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 #include #define _COMPONENT ACPI_TABLES ACPI_MODULE_NAME("tbutils") /* Local prototypes */ #ifdef ACPI_OBSOLETE_FUNCTIONS acpi_status acpi_tb_handle_to_object(u16 table_id, struct acpi_table_desc **table_desc); #endif /******************************************************************************* * * FUNCTION: acpi_tb_is_table_installed * * PARAMETERS: new_table_desc - Descriptor for new table being installed * * RETURN: Status - AE_ALREADY_EXISTS if the table is already installed * * DESCRIPTION: Determine if an ACPI table is already installed * * MUTEX: Table data structures should be locked * ******************************************************************************/ acpi_status acpi_tb_is_table_installed(struct acpi_table_desc *new_table_desc) { struct acpi_table_desc *table_desc; ACPI_FUNCTION_TRACE("tb_is_table_installed"); /* Get the list descriptor and first table descriptor */ table_desc = acpi_gbl_table_lists[new_table_desc->type].next; /* Examine all installed tables of this type */ while (table_desc) { /* * If the table lengths match, perform a full bytewise compare. This * means that we will allow tables with duplicate oem_table_id(s), as * long as the tables are different in some way. * * Checking if the table has been loaded into the namespace means that * we don't check for duplicate tables during the initial installation * of tables within the RSDT/XSDT. */ if ((table_desc->loaded_into_namespace) && (table_desc->pointer->length == new_table_desc->pointer->length) && (!ACPI_MEMCMP (table_desc->pointer, new_table_desc->pointer, new_table_desc->pointer->length))) { /* Match: this table is already installed */ ACPI_DEBUG_PRINT((ACPI_DB_TABLES, "Table [%4.4s] already installed: Rev %X oem_table_id [%8.8s]\n", new_table_desc->pointer->signature, new_table_desc->pointer->revision, new_table_desc->pointer-> oem_table_id)); new_table_desc->owner_id = table_desc->owner_id; new_table_desc->installed_desc = table_desc; return_ACPI_STATUS(AE_ALREADY_EXISTS); } /* Get next table on the list */ table_desc = table_desc->next; } return_ACPI_STATUS(AE_OK); } /******************************************************************************* * * 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_ENTRY(); /* Verify that this is a valid address */ if (!acpi_os_readable(table_header, sizeof(struct acpi_table_header))) { ACPI_ERROR((AE_INFO, "Cannot read table header at %p", 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_ERROR((AE_INFO, "Table signature at %p [%p] has invalid characters", table_header, &signature)); ACPI_WARNING((AE_INFO, "Invalid table signature found: [%4.4s]", ACPI_CAST_PTR(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_ERROR((AE_INFO, "Invalid length in table header %p name %4.4s", table_header, (char *)&signature)); ACPI_WARNING((AE_INFO, "Invalid table header length (0x%X) found", (u32) table_header->length)); ACPI_DUMP_BUFFER(table_header, sizeof(struct acpi_table_header)); return (AE_BAD_HEADER); } return (AE_OK); } /******************************************************************************* * * FUNCTION: acpi_tb_sum_table * * PARAMETERS: Buffer - Buffer to sum * Length - Size of the buffer * * RETURN: 8 bit sum of buffer * * DESCRIPTION: Computes an 8 bit sum of the buffer(length) and returns it. * ******************************************************************************/ u8 acpi_tb_sum_table(void *buffer, u32 length) { acpi_native_uint i; u8 sum = 0; if (!buffer || !length) { return (0); } for (i = 0; i < length; i++) { sum = (u8) (sum + ((u8 *) buffer)[i]); } return (sum); } /******************************************************************************* * * FUNCTION: acpi_tb_generate_checksum * * PARAMETERS: Table - Pointer to a valid ACPI table (with a * standard ACPI header) * * RETURN: 8 bit checksum of buffer * * DESCRIPTION: Computes an 8 bit checksum of the table. * ******************************************************************************/ u8 acpi_tb_generate_checksum(struct acpi_table_header * table) { u8 checksum; /* Sum the entire table as-is */ checksum = acpi_tb_sum_table(table, table->length); /* Subtract off the existing checksum value in the table */ checksum = (u8) (checksum - table->checksum); /* Compute the final checksum */ checksum = (u8) (0 - checksum); return (checksum); } /******************************************************************************* * * FUNCTION: acpi_tb_set_checksum * * PARAMETERS: Table - Pointer to a valid ACPI table (with a * standard ACPI header) * * RETURN: None. Sets the table checksum field * * DESCRIPTION: Computes an 8 bit checksum of the table and inserts the * checksum into the table header. * ******************************************************************************/ void acpi_tb_set_checksum(struct acpi_table_header *table) { table->checksum = acpi_tb_generate_checksum(table); } /******************************************************************************* * * FUNCTION: acpi_tb_verify_table_checksum * * PARAMETERS: *table_header - ACPI table to verify * * RETURN: 8 bit checksum of table * * DESCRIPTION: Generates an 8 bit checksum of table and returns and compares * it to the existing checksum value. * ******************************************************************************/ acpi_status acpi_tb_verify_table_checksum(struct acpi_table_header *table_header) { u8 checksum; ACPI_FUNCTION_TRACE("tb_verify_table_checksum"); /* Compute the checksum on the table */ checksum = acpi_tb_generate_checksum(table_header); /* Checksum ok? */ if (checksum == table_header->checksum) { return_ACPI_STATUS(AE_OK); } ACPI_WARNING((AE_INFO, "Incorrect checksum in table [%4.4s] - is %2.2X, should be %2.2X", table_header->signature, table_header->checksum, checksum)); return_ACPI_STATUS(AE_BAD_CHECKSUM); } #ifdef ACPI_OBSOLETE_FUNCTIONS /******************************************************************************* * * 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. * ******************************************************************************/ 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_ERROR((AE_INFO, "table_id=%X does not exist", table_id)); return (AE_BAD_PARAMETER); } #endif