tbxfroot.c
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上传日期:2013-04-10
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文件大小:11k
- /******************************************************************************
- *
- * Module Name: tbxfroot - Find the root ACPI table (RSDT)
- * $Revision: 52 $
- *
- *****************************************************************************/
- /*
- * Copyright (C) 2000, 2001 R. Byron Moore
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
- #include "acpi.h"
- #include "achware.h"
- #include "actables.h"
- #define _COMPONENT ACPI_TABLES
- MODULE_NAME ("tbxfroot")
- #define RSDP_CHECKSUM_LENGTH 20
- /*******************************************************************************
- *
- * FUNCTION: Acpi_find_root_pointer
- *
- * PARAMETERS: **Rsdp_physical_address - Where to place the RSDP address
- * Flags - Logical/Physical addressing
- *
- * RETURN: Status, Physical address of the RSDP
- *
- * DESCRIPTION: Find the RSDP
- *
- ******************************************************************************/
- acpi_status
- acpi_find_root_pointer (
- u32 flags,
- ACPI_PHYSICAL_ADDRESS *rsdp_physical_address)
- {
- acpi_table_desc table_info;
- acpi_status status;
- 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 foundn"));
- return_ACPI_STATUS (AE_NO_ACPI_TABLES);
- }
- *rsdp_physical_address = 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
- *
- ******************************************************************************/
- u8 *
- acpi_tb_scan_memory_for_rsdp (
- u8 *start_address,
- u32 length)
- {
- u32 offset;
- u8 *mem_rover;
- FUNCTION_TRACE ("Tb_scan_memory_for_rsdp");
- /* Search from given start addr for the requested length */
- for (offset = 0, mem_rover = start_address;
- offset < length;
- offset += RSDP_SCAN_STEP, mem_rover += RSDP_SCAN_STEP) {
- /* The signature and checksum must both be correct */
- if (STRNCMP ((NATIVE_CHAR *) mem_rover,
- RSDP_SIG, sizeof (RSDP_SIG)-1) == 0 &&
- acpi_tb_checksum (mem_rover, RSDP_CHECKSUM_LENGTH) == 0) {
- /* If so, we have found the RSDP */
- ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
- "RSDP located at physical address %pn",mem_rover));
- return_PTR (mem_rover);
- }
- }
- /* Searched entire block, no RSDP was found */
- ACPI_DEBUG_PRINT ((ACPI_DB_INFO,"Searched entire block, no 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
- *
- * DESCRIPTION: Search lower 1_mbyte of memory for the root system descriptor
- * pointer structure. If it is found, set *RSDP to point to it.
- *
- * NOTE: The RSDP must be either in the first 1_k of the Extended
- * BIOS Data Area or between E0000 and FFFFF (ACPI 1.0 section
- * 5.2.2; assertion #421).
- *
- ******************************************************************************/
- acpi_status
- acpi_tb_find_rsdp (
- acpi_table_desc *table_info,
- u32 flags)
- {
- u8 *table_ptr;
- u8 *mem_rover;
- u64 phys_addr;
- acpi_status status = AE_OK;
- FUNCTION_TRACE ("Tb_find_rsdp");
- /*
- * Scan supports either 1) Logical addressing or 2) Physical addressing
- */
- if ((flags & ACPI_MEMORY_MODE) == ACPI_LOGICAL_ADDRESSING) {
- /*
- * 1) Search EBDA (low memory) paragraphs
- */
- status = acpi_os_map_memory (LO_RSDP_WINDOW_BASE, LO_RSDP_WINDOW_SIZE,
- (void **) &table_ptr);
- if (ACPI_FAILURE (status)) {
- return_ACPI_STATUS (status);
- }
- mem_rover = acpi_tb_scan_memory_for_rsdp (table_ptr, LO_RSDP_WINDOW_SIZE);
- acpi_os_unmap_memory (table_ptr, LO_RSDP_WINDOW_SIZE);
- if (mem_rover) {
- /* Found it, return the physical address */
- phys_addr = LO_RSDP_WINDOW_BASE;
- phys_addr += (mem_rover - table_ptr);
- table_info->physical_address = phys_addr;
- return_ACPI_STATUS (AE_OK);
- }
- /*
- * 2) Search upper memory: 16-byte boundaries in E0000h-F0000h
- */
- status = acpi_os_map_memory (HI_RSDP_WINDOW_BASE, HI_RSDP_WINDOW_SIZE,
- (void **) &table_ptr);
- if (ACPI_FAILURE (status)) {
- return_ACPI_STATUS (status);
- }
- mem_rover = acpi_tb_scan_memory_for_rsdp (table_ptr, HI_RSDP_WINDOW_SIZE);
- acpi_os_unmap_memory (table_ptr, HI_RSDP_WINDOW_SIZE);
- if (mem_rover) {
- /* Found it, return the physical address */
- phys_addr = HI_RSDP_WINDOW_BASE;
- phys_addr += (mem_rover - table_ptr);
- table_info->physical_address = phys_addr;
- return_ACPI_STATUS (AE_OK);
- }
- }
- /*
- * Physical addressing
- */
- else {
- /*
- * 1) Search EBDA (low memory) paragraphs
- */
- mem_rover = acpi_tb_scan_memory_for_rsdp ((u8 *) LO_RSDP_WINDOW_BASE,
- LO_RSDP_WINDOW_SIZE);
- if (mem_rover) {
- /* Found it, return the physical address */
- table_info->physical_address = (ACPI_TBLPTR) mem_rover;
- return_ACPI_STATUS (AE_OK);
- }
- /*
- * 2) Search upper memory: 16-byte boundaries in E0000h-F0000h
- */
- mem_rover = acpi_tb_scan_memory_for_rsdp ((u8 *) HI_RSDP_WINDOW_BASE,
- HI_RSDP_WINDOW_SIZE);
- if (mem_rover) {
- /* Found it, return the physical address */
- table_info->physical_address = (ACPI_TBLPTR) mem_rover;
- return_ACPI_STATUS (AE_OK);
- }
- }
- /* RSDP signature was not found */
- return_ACPI_STATUS (AE_NOT_FOUND);
- }
- /*******************************************************************************
- *
- * 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 - 0: Physical/Virtual support
- * Ret_buffer - pointer to a structure containing a buffer to
- * receive the table
- *
- * RETURN: Status
- *
- * DESCRIPTION: This function is called to get an ACPI table. The caller
- * supplies an Out_buffer large enough to contain the entire ACPI
- * table. Upon completion
- * the Out_buffer->Length field will indicate the number of bytes
- * copied into the Out_buffer->Buf_ptr buffer. This table will be
- * a complete table including the header.
- *
- ******************************************************************************/
- acpi_status
- acpi_get_firmware_table (
- acpi_string signature,
- u32 instance,
- u32 flags,
- acpi_table_header **table_pointer)
- {
- ACPI_PHYSICAL_ADDRESS physical_address;
- acpi_table_header *rsdt_ptr = NULL;
- acpi_table_header *table_ptr;
- acpi_status status;
- u32 rsdt_size = 0;
- u32 table_size;
- u32 table_count;
- u32 i;
- u32 j;
- 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);
- }
- if (!acpi_gbl_RSDP) {
- /* Get the RSDP */
- status = acpi_os_get_root_pointer (flags, &physical_address);
- if (ACPI_FAILURE (status)) {
- ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "RSDP not foundn"));
- 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 (physical_address, sizeof (RSDP_DESCRIPTOR),
- (void **) &acpi_gbl_RSDP);
- if (ACPI_FAILURE (status)) {
- return_ACPI_STATUS (status);
- }
- }
- else {
- acpi_gbl_RSDP = (void *) (NATIVE_UINT) physical_address;
- }
- /*
- * The signature and checksum must both be correct
- */
- if (STRNCMP ((NATIVE_CHAR *) acpi_gbl_RSDP, RSDP_SIG, sizeof (RSDP_SIG)-1) != 0) {
- /* Nope, BAD Signature */
- status = AE_BAD_SIGNATURE;
- goto cleanup;
- }
- if (acpi_tb_checksum (acpi_gbl_RSDP, RSDP_CHECKSUM_LENGTH) != 0) {
- /* Nope, BAD Checksum */
- status = AE_BAD_CHECKSUM;
- goto cleanup;
- }
- }
- ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
- "RSDP located at %p, RSDT physical=%8.8X%8.8X n",
- acpi_gbl_RSDP, HIDWORD(acpi_gbl_RSDP->rsdt_physical_address),
- LODWORD(acpi_gbl_RSDP->rsdt_physical_address)));
- /* Get the RSDT and validate it */
- physical_address = acpi_tb_get_rsdt_address ();
- status = acpi_tb_get_table_pointer (physical_address, flags, &rsdt_size, &rsdt_ptr);
- if (ACPI_FAILURE (status)) {
- return_ACPI_STATUS (status);
- }
- status = acpi_tb_validate_rsdt (rsdt_ptr);
- if (ACPI_FAILURE (status)) {
- goto cleanup;
- }
- /* Get the number of table pointers within the RSDT */
- table_count = acpi_tb_get_table_count (acpi_gbl_RSDP, rsdt_ptr);
- /*
- * 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 */
- if (acpi_gbl_RSDP->revision < 2) {
- physical_address = ((RSDT_DESCRIPTOR *) rsdt_ptr)->table_offset_entry[i];
- }
- else {
- physical_address = (ACPI_PHYSICAL_ADDRESS)
- ACPI_GET_ADDRESS (((xsdt_descriptor *) rsdt_ptr)->table_offset_entry[i]);
- }
- /* Get addressibility if necessary */
- status = acpi_tb_get_table_pointer (physical_address, flags, &table_size, &table_ptr);
- if (ACPI_FAILURE (status)) {
- goto cleanup;
- }
- /* Compare table signatures and table instance */
- if (!STRNCMP ((char *) table_ptr, signature, STRLEN (signature))) {
- /* An instance of the table was found */
- j++;
- if (j >= instance) {
- /* Found the correct instance */
- *table_pointer = table_ptr;
- goto cleanup;
- }
- }
- /* Delete table mapping if using virtual addressing */
- if ((table_size) &&
- ((flags & ACPI_MEMORY_MODE) == ACPI_LOGICAL_ADDRESSING)) {
- acpi_os_unmap_memory (table_ptr, table_size);
- }
- }
- /* Did not find the table */
- status = AE_NOT_EXIST;
- cleanup:
- if (rsdt_size) {
- acpi_os_unmap_memory (rsdt_ptr, rsdt_size);
- }
- return_ACPI_STATUS (status);
- }