+++ /dev/null
-/******************************************************************************
- *
- * Module Name: tbxfroot - Find the root ACPI table (RSDT)
- *
- *****************************************************************************/
-
-/*
- * Copyright (C) 2000 - 2008, Intel Corp.
- * 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/accommon.h>
-#include <acpi/actables.h>
-
-#define _COMPONENT ACPI_TABLES
-ACPI_MODULE_NAME("tbxfroot")
-
-/* Local prototypes */
-static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length);
-
-static acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp);
-
-/*******************************************************************************
- *
- * FUNCTION: acpi_tb_validate_rsdp
- *
- * PARAMETERS: Rsdp - Pointer to unvalidated RSDP
- *
- * RETURN: Status
- *
- * DESCRIPTION: Validate the RSDP (ptr)
- *
- ******************************************************************************/
-
-static acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp)
-{
- ACPI_FUNCTION_ENTRY();
-
- /*
- * The signature and checksum must both be correct
- *
- * Note: Sometimes there exists more than one RSDP in memory; the valid
- * RSDP has a valid checksum, all others have an invalid checksum.
- */
- if (ACPI_STRNCMP((char *)rsdp, ACPI_SIG_RSDP, sizeof(ACPI_SIG_RSDP) - 1)
- != 0) {
-
- /* Nope, BAD Signature */
-
- return (AE_BAD_SIGNATURE);
- }
-
- /* Check the standard checksum */
-
- if (acpi_tb_checksum((u8 *) rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0) {
- return (AE_BAD_CHECKSUM);
- }
-
- /* Check extended checksum if table version >= 2 */
-
- if ((rsdp->revision >= 2) &&
- (acpi_tb_checksum((u8 *) rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0)) {
- return (AE_BAD_CHECKSUM);
- }
-
- return (AE_OK);
-}
-
-/*******************************************************************************
- *
- * FUNCTION: acpi_find_root_pointer
- *
- * PARAMETERS: table_address - Where the table pointer is returned
- *
- * RETURN: Status, RSDP physical address
- *
- * DESCRIPTION: Search lower 1_mbyte of memory for the root system descriptor
- * pointer structure. If it is found, set *RSDP to point to it.
- *
- * NOTE1: The RSDP must be either in the first 1_k of the Extended
- * BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.)
- * Only a 32-bit physical address is necessary.
- *
- * NOTE2: This function is always available, regardless of the
- * initialization state of the rest of ACPI.
- *
- ******************************************************************************/
-
-acpi_status acpi_find_root_pointer(acpi_size *table_address)
-{
- u8 *table_ptr;
- u8 *mem_rover;
- u32 physical_address;
-
- ACPI_FUNCTION_TRACE(acpi_find_root_pointer);
-
- /* 1a) Get the location of the Extended BIOS Data Area (EBDA) */
-
- table_ptr = acpi_os_map_memory((acpi_physical_address)
- ACPI_EBDA_PTR_LOCATION,
- ACPI_EBDA_PTR_LENGTH);
- if (!table_ptr) {
- ACPI_ERROR((AE_INFO,
- "Could not map memory at %8.8X for length %X",
- ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH));
-
- return_ACPI_STATUS(AE_NO_MEMORY);
- }
-
- ACPI_MOVE_16_TO_32(&physical_address, table_ptr);
-
- /* Convert segment part to physical address */
-
- physical_address <<= 4;
- acpi_os_unmap_memory(table_ptr, ACPI_EBDA_PTR_LENGTH);
-
- /* EBDA present? */
-
- if (physical_address > 0x400) {
- /*
- * 1b) Search EBDA paragraphs (EBDA is required to be a
- * minimum of 1_k length)
- */
- table_ptr = acpi_os_map_memory((acpi_physical_address)
- physical_address,
- ACPI_EBDA_WINDOW_SIZE);
- if (!table_ptr) {
- ACPI_ERROR((AE_INFO,
- "Could not map memory at %8.8X for length %X",
- physical_address, ACPI_EBDA_WINDOW_SIZE));
-
- return_ACPI_STATUS(AE_NO_MEMORY);
- }
-
- mem_rover =
- acpi_tb_scan_memory_for_rsdp(table_ptr,
- ACPI_EBDA_WINDOW_SIZE);
- acpi_os_unmap_memory(table_ptr, ACPI_EBDA_WINDOW_SIZE);
-
- if (mem_rover) {
-
- /* Return the physical address */
-
- physical_address +=
- (u32) ACPI_PTR_DIFF(mem_rover, table_ptr);
-
- *table_address = physical_address;
- return_ACPI_STATUS(AE_OK);
- }
- }
-
- /*
- * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh
- */
- table_ptr = acpi_os_map_memory((acpi_physical_address)
- ACPI_HI_RSDP_WINDOW_BASE,
- ACPI_HI_RSDP_WINDOW_SIZE);
-
- if (!table_ptr) {
- ACPI_ERROR((AE_INFO,
- "Could not map memory at %8.8X for length %X",
- ACPI_HI_RSDP_WINDOW_BASE,
- ACPI_HI_RSDP_WINDOW_SIZE));
-
- return_ACPI_STATUS(AE_NO_MEMORY);
- }
-
- mem_rover =
- acpi_tb_scan_memory_for_rsdp(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);
- acpi_os_unmap_memory(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);
-
- if (mem_rover) {
-
- /* Return the physical address */
-
- physical_address = (u32)
- (ACPI_HI_RSDP_WINDOW_BASE +
- ACPI_PTR_DIFF(mem_rover, table_ptr));
-
- *table_address = physical_address;
- return_ACPI_STATUS(AE_OK);
- }
-
- /* A valid RSDP was not found */
-
- ACPI_ERROR((AE_INFO, "A valid RSDP was not found"));
- return_ACPI_STATUS(AE_NOT_FOUND);
-}
-
-/*******************************************************************************
- *
- * FUNCTION: acpi_tb_scan_memory_for_rsdp
- *
- * PARAMETERS: start_address - Starting pointer for search
- * Length - Maximum length to search
- *
- * RETURN: Pointer to the RSDP if found, otherwise NULL.
- *
- * DESCRIPTION: Search a block of memory for the RSDP signature
- *
- ******************************************************************************/
-static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length)
-{
- acpi_status status;
- u8 *mem_rover;
- u8 *end_address;
-
- ACPI_FUNCTION_TRACE(tb_scan_memory_for_rsdp);
-
- end_address = start_address + length;
-
- /* Search from given start address for the requested length */
-
- for (mem_rover = start_address; mem_rover < end_address;
- mem_rover += ACPI_RSDP_SCAN_STEP) {
-
- /* The RSDP signature and checksum must both be correct */
-
- status =
- acpi_tb_validate_rsdp(ACPI_CAST_PTR
- (struct acpi_table_rsdp, mem_rover));
- if (ACPI_SUCCESS(status)) {
-
- /* Sig and checksum valid, we have found a real RSDP */
-
- ACPI_DEBUG_PRINT((ACPI_DB_INFO,
- "RSDP located at physical address %p\n",
- mem_rover));
- return_PTR(mem_rover);
- }
-
- /* No sig match or bad checksum, keep searching */
- }
-
- /* Searched entire block, no RSDP was found */
-
- ACPI_DEBUG_PRINT((ACPI_DB_INFO,
- "Searched entire block from %p, valid RSDP was not found\n",
- start_address));
- return_PTR(NULL);
-}
git.samba.org / sfrench / cifs-2.6.git / blobdiff