/******************************************************************************
*
* Module Name: tbxfroot - Find the root ACPI table (RSDT)
*
*****************************************************************************/
/*
* 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 <linux/module.h>
#include <acpi/acpi.h>
#include <acpi/actables.h>
#define _COMPONENT ACPI_TABLES
ACPI_MODULE_NAME ("tbxfroot")
/* Local prototypes */
static acpi_status
acpi_tb_find_rsdp (
struct acpi_table_desc *table_info,
u32 flags);
static u8 *
acpi_tb_scan_memory_for_rsdp (
u8 *start_address,
u32 length);
/*******************************************************************************
*
* FUNCTION: acpi_tb_find_table
*
* PARAMETERS: Signature - String with ACPI table signature
* oem_id - String with the table OEM ID
* oem_table_id - String with the OEM Table ID
* table_ptr - Where the table pointer is returned
*
* RETURN: Status
*
* DESCRIPTION: Find an ACPI table (in the RSDT/XSDT) that matches the
* Signature, OEM ID and OEM Table ID.
*
******************************************************************************/
acpi_status
acpi_tb_find_table (
char *signature,
char *oem_id,
char *oem_table_id,
struct acpi_table_header **table_ptr)
{
acpi_status status;
struct acpi_table_header *table;
ACPI_FUNCTION_TRACE ("tb_find_table");
/* Validate string lengths */
if ((ACPI_STRLEN (signature) > ACPI_NAME_SIZE) ||
(ACPI_STRLEN (oem_id) > sizeof (table->oem_id)) ||
(ACPI_STRLEN (oem_table_id) > sizeof (table->oem_table_id))) {
return_ACPI_STATUS (AE_AML_STRING_LIMIT);
}
if (!ACPI_STRNCMP (signature, DSDT_SIG, ACPI_NAME_SIZE)) {
/*
* The DSDT pointer is contained in the FADT, not the RSDT.
* This code should suffice, because the only code that would perform
* a "find" on the DSDT is the data_table_region() AML opcode -- in
* which case, the DSDT is guaranteed to be already loaded.
* If this becomes insufficient, the FADT will have to be found first.
*/
if (!acpi_gbl_DSDT) {
return_ACPI_STATUS (AE_NO_ACPI_TABLES);
}
table = acpi_gbl_DSDT;
}
else {
/* Find the table */
status = acpi_get_firmware_table (signature, 1,
ACPI_LOGICAL_ADDRESSING, &table);
if (ACPI_FAILURE (status)) {
return_ACPI_STATUS (status);
}
}
/* Check oem_id and oem_table_id */
if ((oem_id[0] && ACPI_STRNCMP (
oem_id, table->oem_id,
sizeof (table->oem_id))) ||
(oem_table_id[0] && ACPI_STRNCMP (
oem_table_id, table->oem_table_id,
sizeof (table->oem_table_id)))) {
return_ACPI_STATUS (AE_AML_NAME_NOT_FOUND);
}
ACPI_DEBUG_PRINT ((ACPI_DB_TABLES, "Found table [%4.4s]\n",
table->signature));
*table_ptr = table;
return_ACPI_STATUS (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_get_firmware_table
*
* PARAMETERS: Signature - Any ACPI table signature
* Instance - the non zero instance of the table, allows
* support for multiple tables of the same type
* Flags - Physical/Virtual support
* table_pointer - Where a buffer containing the table is
* returned
*
* RETURN: Status
*
* DESCRIPTION: This function is called to get an ACPI table. A buffer is
* allocated for the table and returned in table_pointer.
* This table will be a complete table including the header.
*
******************************************************************************/
acpi_status
acpi_get_firmware_table (
acpi_string signature,
u32 instance,
u32 flags,
struct acpi_table_header **table_pointer)
{
acpi_status status;
struct acpi_pointer address;
struct acpi_table_header *header = NULL;
struct acpi_table_desc *table_info = NULL;
struct acpi_table_desc *rsdt_info;
u32 table_count;
u32 i;
u32 j;
ACPI_FUNCTION_TRACE ("acpi_get_firmware_table");
/*
* Ensure that at least the table manager is initialized. We don't
* require that the entire ACPI subsystem is up for this interface.
* If we have a buffer, we must have a length too
*/
if ((instance == 0) ||
(!signature) ||
(!table_pointer)) {
return_ACPI_STATUS (AE_BAD_PARAMETER);
}
/* Ensure that we have a RSDP */
if (!acpi_gbl_RSDP) {
/* Get the RSDP */
status = acpi_os_get_root_pointer (flags, &address);
if (ACPI_FAILURE (status)) {
ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "RSDP not found\n"));
return_ACPI_STATUS (AE_NO_ACPI_TABLES);
}
/* Map and validate the RSDP */
if ((flags & ACPI_MEMORY_MODE) == ACPI_LOGICAL_ADDRESSING) {
status = acpi_os_map_memory (address.pointer.physical,
sizeof (struct rsdp_descriptor), (void *) &acpi_gbl_RSDP);
if (ACPI_FAILURE (status)) {
return_ACPI_STATUS (status);
}
}
else {
acpi_gbl_RSDP = address.pointer.logical;
}
/* The signature and checksum must both be correct */
if (ACPI_STRNCMP ((char *) acpi_gbl_RSDP, RSDP_SIG,
sizeof (RSDP_SIG)-1) != 0) {
/* Nope, BAD Signature */
return_ACPI_STATUS (AE_BAD_SIGNATURE);
}
if (acpi_tb_checksum (acpi_gbl_RSDP, ACPI_RSDP_CHECKSUM_LENGTH) != 0) {
/* Nope, BAD Checksum */
return_ACPI_STATUS (AE_BAD_CHECKSUM);
}
}
/* Get the RSDT address via the RSDP */
acpi_tb_get_rsdt_address (&address);
ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
"RSDP located at %p, RSDT physical=%8.8X%8.8X \n",
acpi_gbl_RSDP,
ACPI_FORMAT_UINT64 (address.pointer.value)));
/* Insert processor_mode flags */
address.pointer_type |= flags;
/* Get and validate the RSDT */
rsdt_info = ACPI_MEM_CALLOCATE (sizeof (struct acpi_table_desc));
if (!rsdt_info) {
return_ACPI_STATUS (AE_NO_MEMORY);
}
status = acpi_tb_get_table (&address, rsdt_info);
if (ACPI_FAILURE (status)) {
goto cleanup;
}
status = acpi_tb_validate_rsdt (rsdt_info->pointer);
if (ACPI_FAILURE (status)) {
goto cleanup;
}
/* Allocate a scratch table header and table descriptor */
header = ACPI_MEM_ALLOCATE (sizeof (struct acpi_table_header));
if (!header) {
status = AE_NO_MEMORY;
goto cleanup;
}
table_info = ACPI_MEM_ALLOCATE (sizeof (struct acpi_table_desc));
if (!table_info) {
status = AE_NO_MEMORY;
goto cleanup;
}
/* Get the number of table pointers within the RSDT */
table_count = acpi_tb_get_table_count (acpi_gbl_RSDP, rsdt_info->pointer);
address.pointer_type = acpi_gbl_table_flags | flags;
/*
* Search the RSDT/XSDT for the correct instance of the
* requested table
*/
for (i = 0, j = 0; i < table_count; i++) {
/* Get the next table pointer, handle RSDT vs. XSDT */
if (acpi_gbl_RSDP->revision < 2) {
address.pointer.value = (ACPI_CAST_PTR (
RSDT_DESCRIPTOR, rsdt_info->pointer))->table_offset_entry[i];
}
else {
address.pointer.value = (ACPI_CAST_PTR (
XSDT_DESCRIPTOR, rsdt_info->pointer))->table_offset_entry[i];
}
/* Get the table header */
status = acpi_tb_get_table_header (&address, header);
if (ACPI_FAILURE (status)) {
goto cleanup;
}
/* Compare table signatures and table instance */
if (!ACPI_STRNCMP (header->signature, signature, ACPI_NAME_SIZE)) {
/* An instance of the table was found */
j++;
if (j >= instance) {
/* Found the correct instance, get the entire table */
status = acpi_tb_get_table_body (&address, header, table_info);
if (ACPI_FAILURE (status)) {
goto cleanup;
}
*table_pointer = table_info->pointer;
goto cleanup;
}
}
}
/* Did not find the table */
status = AE_NOT_EXIST;
cleanup:
acpi_os_unmap_memory (rsdt_info->pointer,
(acpi_size) rsdt_info->pointer->length);
ACPI_MEM_FREE (rsdt_info);
if (header) {
ACPI_MEM_FREE (header);
}
if (table_info) {
ACPI_MEM_FREE (table_info);
}
return_ACPI_STATUS (status);
}
EXPORT_SYMBOL(acpi_get_firmware_table);
/* TBD: Move to a new file */
#if ACPI_MACHINE_WIDTH != 16
/*******************************************************************************
*
* FUNCTION: acpi_find_root_pointer
*
* PARAMETERS: Flags - Logical/Physical addressing
* rsdp_address - Where to place the RSDP address
*
* RETURN: Status, Physical address of the RSDP
*
* DESCRIPTION: Find the RSDP
*
******************************************************************************/
acpi_status
acpi_find_root_pointer (
u32 flags,
struct acpi_pointer *rsdp_address)
{
struct acpi_table_desc table_info;
acpi_status status;
ACPI_FUNCTION_TRACE ("acpi_find_root_pointer");
/* Get the RSDP */
status = acpi_tb_find_rsdp (&table_info, flags);
if (ACPI_FAILURE (status)) {
ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
"RSDP structure not found, %s Flags=%X\n",
acpi_format_exception (status), flags));
return_ACPI_STATUS (AE_NO_ACPI_TABLES);
}
rsdp_address->pointer_type = ACPI_PHYSICAL_POINTER;
rsdp_address->pointer.physical = table_info.physical_address;
return_ACPI_STATUS (AE_OK);
}
/*******************************************************************************
*
* 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)
{
u8 *mem_rover;
u8 *end_address;
u8 checksum;
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 signature and checksum must both be correct */
if (ACPI_STRNCMP ((char *) mem_rover,
RSDP_SIG, sizeof (RSDP_SIG) - 1) != 0) {
/* No signature match, keep looking */
continue;
}
/* Signature matches, check the appropriate checksum */
if ((ACPI_CAST_PTR (struct rsdp_descriptor, mem_rover))->revision < 2) {
/* ACPI version 1.0 */
checksum = acpi_tb_checksum (mem_rover, ACPI_RSDP_CHECKSUM_LENGTH);
}
else {
/* Post ACPI 1.0, use extended_checksum */
checksum = acpi_tb_checksum (mem_rover, ACPI_RSDP_XCHECKSUM_LENGTH);
}
if (checksum == 0) {
/* Checksum valid, we have found a valid RSDP */
ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
"RSDP located at physical address %p\n", mem_rover));
return_PTR (mem_rover);
}
ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
"Found an RSDP at physical address %p, but it has a bad checksum\n",
mem_rover));
}
/* Searched entire block, no RSDP was found */
ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
"Searched entire block, no valid RSDP was found.\n"));
return_PTR (NULL);
}
/*******************************************************************************
*
* FUNCTION: acpi_tb_find_rsdp
*
* PARAMETERS: table_info - Where the table info is returned
* Flags - Current memory mode (logical vs.
* physical addressing)
*
* 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.
*
******************************************************************************/
static acpi_status
acpi_tb_find_rsdp (
struct acpi_table_desc *table_info,
u32 flags)
{
u8 *table_ptr;
u8 *mem_rover;
u32 physical_address;
acpi_status status;
ACPI_FUNCTION_TRACE ("tb_find_rsdp");
/*
* Scan supports either logical addressing or physical addressing
*/
if ((flags & ACPI_MEMORY_MODE) == ACPI_LOGICAL_ADDRESSING) {
/* 1a) Get the location of the Extended BIOS Data Area (EBDA) */
status = acpi_os_map_memory (
(acpi_physical_address) ACPI_EBDA_PTR_LOCATION,
ACPI_EBDA_PTR_LENGTH, (void *) &table_ptr);
if (ACPI_FAILURE (status)) {
ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
"Could not map memory at %8.8X for length %X\n",
ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH));
return_ACPI_STATUS (status);
}
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)
*/
status = acpi_os_map_memory (
(acpi_physical_address) physical_address,
ACPI_EBDA_WINDOW_SIZE, (void *) &table_ptr);
if (ACPI_FAILURE (status)) {
ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
"Could not map memory at %8.8X for length %X\n",
physical_address, ACPI_EBDA_WINDOW_SIZE));
return_ACPI_STATUS (status);
}
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) {
/* Found it, return the physical address */
physical_address += ACPI_PTR_DIFF (mem_rover, table_ptr);
table_info->physical_address =
(acpi_physical_address) physical_address;
return_ACPI_STATUS (AE_OK);
}
}
/*
* 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh
*/
status = acpi_os_map_memory (
(acpi_physical_address) ACPI_HI_RSDP_WINDOW_BASE,
ACPI_HI_RSDP_WINDOW_SIZE, (void *) &table_ptr);
if (ACPI_FAILURE (status)) {
ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
"Could not map memory at %8.8X for length %X\n",
ACPI_HI_RSDP_WINDOW_BASE, ACPI_HI_RSDP_WINDOW_SIZE));
return_ACPI_STATUS (status);
}
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) {
/* Found it, return the physical address */
physical_address =
ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF (mem_rover, table_ptr);
table_info->physical_address =
(acpi_physical_address) physical_address;
return_ACPI_STATUS (AE_OK);
}
}
/*
* Physical addressing
*/
else {
/* 1a) Get the location of the EBDA */
ACPI_MOVE_16_TO_32 (&physical_address, ACPI_EBDA_PTR_LOCATION);
physical_address <<= 4; /* Convert segment to physical address */
/* EBDA present? */
if (physical_address > 0x400) {
/*
* 1b) Search EBDA paragraphs (EBDa is required to be a minimum of
* 1_k length)
*/
mem_rover = acpi_tb_scan_memory_for_rsdp (
ACPI_PHYSADDR_TO_PTR (physical_address),
ACPI_EBDA_WINDOW_SIZE);
if (mem_rover) {
/* Found it, return the physical address */
table_info->physical_address = ACPI_TO_INTEGER (mem_rover);
return_ACPI_STATUS (AE_OK);
}
}
/* 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh */
mem_rover = acpi_tb_scan_memory_for_rsdp (
ACPI_PHYSADDR_TO_PTR (ACPI_HI_RSDP_WINDOW_BASE),
ACPI_HI_RSDP_WINDOW_SIZE);
if (mem_rover) {
/* Found it, return the physical address */
table_info->physical_address = ACPI_TO_INTEGER (mem_rover);
return_ACPI_STATUS (AE_OK);
}
}
/* RSDP signature was not found */
return_ACPI_STATUS (AE_NOT_FOUND);
}
#endif
