drivers/acpi/acpica/tbxfroot.c - kernel/quantenna - Git at Google

 /******************************************************************************
  *
  * Module Name: tbxfroot - Find the root ACPI table (RSDT)
  *
  *****************************************************************************/

 /*
  * Copyright (C) 2000 - 2016, 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 "accommon.h"
 #include "actables.h"

 #define _COMPONENT          ACPI_TABLES
 ACPI_MODULE_NAME("tbxfroot")

 /*******************************************************************************
  *
  * FUNCTION:    acpi_tb_get_rsdp_length
  *
  * PARAMETERS:  rsdp                - Pointer to RSDP
  *
  * RETURN:      Table length
  *
  * DESCRIPTION: Get the length of the RSDP
  *
  ******************************************************************************/
 u32 acpi_tb_get_rsdp_length(struct acpi_table_rsdp *rsdp)
 {

 	if (!ACPI_VALIDATE_RSDP_SIG(rsdp->signature)) {

 		/* BAD Signature */

 		return (0);
 	}

 	/* "Length" field is available if table version >= 2 */

 	if (rsdp->revision >= 2) {
 		return (rsdp->length);
 	} else {
 		return (ACPI_RSDP_CHECKSUM_LENGTH);
 	}
 }

 /*******************************************************************************
  *
  * FUNCTION:    acpi_tb_validate_rsdp
  *
  * PARAMETERS:  rsdp                - Pointer to unvalidated RSDP
  *
  * RETURN:      Status
  *
  * DESCRIPTION: Validate the RSDP (ptr)
  *
  ******************************************************************************/

 acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp)
 {

 	/*
 	 * 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_VALIDATE_RSDP_SIG(rsdp->signature)) {

 		/* 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 1Mbyte 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 1K 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 __init acpi_find_root_pointer(acpi_physical_address *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 0x%8.8X for length %u",
 			    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 1K 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 0x%8.8X for length %u",
 				    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 =
 			    (acpi_physical_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 0x%8.8X for length %u",
 			    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 = (acpi_physical_address)physical_address;
 		return_ACPI_STATUS(AE_OK);
 	}

 	/* A valid RSDP was not found */

 	ACPI_BIOS_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
  *
  ******************************************************************************/
 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);
 }
	/******************************************************************************
	*
	* Module Name: tbxfroot - Find the root ACPI table (RSDT)
	*
	*****************************************************************************/

	/*
	* Copyright (C) 2000 - 2016, 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 "accommon.h"
	#include "actables.h"

	#define _COMPONENT ACPI_TABLES
	ACPI_MODULE_NAME("tbxfroot")

	/*******************************************************************************
	*
	* FUNCTION: acpi_tb_get_rsdp_length
	*
	* PARAMETERS: rsdp - Pointer to RSDP
	*
	* RETURN: Table length
	*
	* DESCRIPTION: Get the length of the RSDP
	*
	******************************************************************************/
	u32 acpi_tb_get_rsdp_length(struct acpi_table_rsdp *rsdp)
	{

	if (!ACPI_VALIDATE_RSDP_SIG(rsdp->signature)) {

	/* BAD Signature */

	return (0);
	}

	/* "Length" field is available if table version >= 2 */

	if (rsdp->revision >= 2) {
	return (rsdp->length);
	} else {
	return (ACPI_RSDP_CHECKSUM_LENGTH);
	}
	}

	/*******************************************************************************
	*
	* FUNCTION: acpi_tb_validate_rsdp
	*
	* PARAMETERS: rsdp - Pointer to unvalidated RSDP
	*
	* RETURN: Status
	*
	* DESCRIPTION: Validate the RSDP (ptr)
	*
	******************************************************************************/

	acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp)
	{

	/*
	* 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_VALIDATE_RSDP_SIG(rsdp->signature)) {

	/* 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 1Mbyte 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 1K 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 __init acpi_find_root_pointer(acpi_physical_address *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 0x%8.8X for length %u",
	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 1K 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 0x%8.8X for length %u",
	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 =
	(acpi_physical_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 0x%8.8X for length %u",
	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 = (acpi_physical_address)physical_address;
	return_ACPI_STATUS(AE_OK);
	}

	/* A valid RSDP was not found */

	ACPI_BIOS_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
	*
	******************************************************************************/
	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);
	}