C++ ACPI_DIV_8函数代码示例

static acpi_status
acpi_hw_validate_io_request(acpi_io_address address, u32 bit_width)
{
	u32 i;
	u32 byte_width;
	acpi_io_address last_address;
	const struct acpi_port_info *port_info;

	ACPI_FUNCTION_TRACE(hw_validate_io_request);

	/* Supported widths are 8/16/32 */

	if ((bit_width != 8) && (bit_width != 16) && (bit_width != 32)) {
		ACPI_ERROR((AE_INFO,
			    "Bad BitWidth parameter: %8.8X", bit_width));
		return AE_BAD_PARAMETER;
	}

	port_info = acpi_protected_ports;
	byte_width = ACPI_DIV_8(bit_width);
	last_address = address + byte_width - 1;

	ACPI_DEBUG_PRINT((ACPI_DB_IO, "Address %p LastAddress %p Length %X",
			  ACPI_CAST_PTR(void, address), ACPI_CAST_PTR(void,
								      last_address),
			  byte_width));

	/* Maximum 16-bit address in I/O space */

	if (last_address > ACPI_UINT16_MAX) {
		ACPI_ERROR((AE_INFO,
			    "Illegal I/O port address/length above 64K: %p/0x%X",
			    ACPI_CAST_PTR(void, address), byte_width));
		return_ACPI_STATUS(AE_LIMIT);
	}

static ACPI_NAMESPACE_NODE *
AcpiDmGetResourceNode (
    ACPI_NAMESPACE_NODE     *BufferNode,
    UINT32                  BitIndex)
{
    ACPI_NAMESPACE_NODE     *Node;
    UINT32                  ByteIndex = ACPI_DIV_8 (BitIndex);


    /*
     * Child list contains an entry for each resource descriptor. Find
     * the descriptor that corresponds to the Index.
     *
     * If there are no children, this is not a resource template
     */
    Node = BufferNode->Child;
    while (Node)
    {
        /*
         * Check if the Index falls within this resource.
         *
         * Value contains the resource offset, Object contains the resource
         * length (both in bytes)
         */
        if ((ByteIndex >= Node->Value) &&
            (ByteIndex < (Node->Value + Node->Length)))
        {
            return (Node);
        }

        Node = Node->Peer;
    }

    return (NULL);
}

acpi_status
acpi_ex_data_table_space_handler (
	u32                             function,
	acpi_physical_address           address,
	u32                             bit_width,
	acpi_integer                    *value,
	void                            *handler_context,
	void                            *region_context)
{
	acpi_status                     status = AE_OK;
	u32                             byte_width = ACPI_DIV_8 (bit_width);
	u32                             i;
	char                            *logical_addr_ptr;


	ACPI_FUNCTION_TRACE ("ex_data_table_space_handler");


	logical_addr_ptr = ACPI_PHYSADDR_TO_PTR (address);


   /* Perform the memory read or write */

	switch (function) {
	case ACPI_READ:

		for (i = 0; i < byte_width; i++) {
			((char *) value) [i] = logical_addr_ptr[i];
		}
		break;

	case ACPI_WRITE:
	default:

		return_ACPI_STATUS (AE_SUPPORT);
	}

	return_ACPI_STATUS (status);
}

acpi_status
acpi_ex_prep_common_field_object(union acpi_operand_object *obj_desc,
				 u8 field_flags,
				 u8 field_attribute,
				 u32 field_bit_position, u32 field_bit_length)
{
	u32 access_bit_width;
	u32 byte_alignment;
	u32 nearest_byte_address;

	ACPI_FUNCTION_TRACE(ex_prep_common_field_object);

	/*
	 * Note: the structure being initialized is the
	 * ACPI_COMMON_FIELD_INFO;  No structure fields outside of the common
	 * area are initialized by this procedure.
	 */
	obj_desc->common_field.field_flags = field_flags;
	obj_desc->common_field.attribute = field_attribute;
	obj_desc->common_field.bit_length = field_bit_length;

	/*
	 * Decode the access type so we can compute offsets.  The access type gives
	 * two pieces of information - the width of each field access and the
	 * necessary byte_alignment (address granularity) of the access.
	 *
	 * For any_acc, the access_bit_width is the largest width that is both
	 * necessary and possible in an attempt to access the whole field in one
	 * I/O operation.  However, for any_acc, the byte_alignment is always one
	 * byte.
	 *
	 * For all Buffer Fields, the byte_alignment is always one byte.
	 *
	 * For all other access types (Byte, Word, Dword, Qword), the Bitwidth is
	 * the same (equivalent) as the byte_alignment.
	 */
	access_bit_width = acpi_ex_decode_field_access(obj_desc, field_flags,
						       &byte_alignment);
	if (!access_bit_width) {
		return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
	}

	/* Setup width (access granularity) fields */

	obj_desc->common_field.access_byte_width = (u8)
	    ACPI_DIV_8(access_bit_width);	/* 1,  2,  4,  8 */

	obj_desc->common_field.access_bit_width = (u8) access_bit_width;

	/*
	 * base_byte_offset is the address of the start of the field within the
	 * region.  It is the byte address of the first *datum* (field-width data
	 * unit) of the field. (i.e., the first datum that contains at least the
	 * first *bit* of the field.)
	 *
	 * Note: byte_alignment is always either equal to the access_bit_width or 8
	 * (Byte access), and it defines the addressing granularity of the parent
	 * region or buffer.
	 */
	nearest_byte_address =
	    ACPI_ROUND_BITS_DOWN_TO_BYTES(field_bit_position);
	obj_desc->common_field.base_byte_offset = (u32)
	    ACPI_ROUND_DOWN(nearest_byte_address, byte_alignment);

	/*
	 * start_field_bit_offset is the offset of the first bit of the field within
	 * a field datum.
	 */
	obj_desc->common_field.start_field_bit_offset = (u8)
	    (field_bit_position -
	     ACPI_MUL_8(obj_desc->common_field.base_byte_offset));

	return_ACPI_STATUS(AE_OK);
}

static u32
acpi_ex_generate_access(u32 field_bit_offset,
			u32 field_bit_length, u32 region_length)
{
	u32 field_byte_length;
	u32 field_byte_offset;
	u32 field_byte_end_offset;
	u32 access_byte_width;
	u32 field_start_offset;
	u32 field_end_offset;
	u32 minimum_access_width = 0xFFFFFFFF;
	u32 minimum_accesses = 0xFFFFFFFF;
	u32 accesses;

	ACPI_FUNCTION_TRACE(ex_generate_access);

	/*                                                                  */

	field_byte_offset = ACPI_DIV_8(ACPI_ROUND_DOWN(field_bit_offset, 8));
	field_byte_end_offset = ACPI_DIV_8(ACPI_ROUND_UP(field_bit_length +
							 field_bit_offset, 8));
	field_byte_length = field_byte_end_offset - field_byte_offset;

	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
			  "Bit length %u, Bit offset %u\n",
			  field_bit_length, field_bit_offset));

	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
			  "Byte Length %u, Byte Offset %u, End Offset %u\n",
			  field_byte_length, field_byte_offset,
			  field_byte_end_offset));

	/*
                                                                      
                                                
   
                                                                        
  */
	for (access_byte_width = 1; access_byte_width <= 8;
	     access_byte_width <<= 1) {
		/*
                                                                      
                                                             
                                                                       
                                                                   
                  
   */
		if (ACPI_ROUND_UP(field_byte_end_offset, access_byte_width) <=
		    region_length) {
			field_start_offset =
			    ACPI_ROUND_DOWN(field_byte_offset,
					    access_byte_width) /
			    access_byte_width;

			field_end_offset =
			    ACPI_ROUND_UP((field_byte_length +
					   field_byte_offset),
					  access_byte_width) /
			    access_byte_width;

			accesses = field_end_offset - field_start_offset;

			ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
					  "AccessWidth %u end is within region\n",
					  access_byte_width));

			ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
					  "Field Start %u, Field End %u -- requires %u accesses\n",
					  field_start_offset, field_end_offset,
					  accesses));

			/*                          */

			if (accesses <= 1) {
				ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
						  "Entire field can be accessed with one operation of size %u\n",
						  access_byte_width));
				return_VALUE(access_byte_width);
			}

			/*
                                                                
                                                 
    */
			if (accesses < minimum_accesses) {
				minimum_accesses = accesses;
				minimum_access_width = access_byte_width;
			}
		} else {
			ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
					  "AccessWidth %u end is NOT within region\n",
					  access_byte_width));
			if (access_byte_width == 1) {
				ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
						  "Field goes beyond end-of-region!\n"));

				/*                                         */

				return_VALUE(0);
			}
//.........这里部分代码省略.........

//.........这里部分代码省略.........

		ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
				  "Bank Field: BitOff %X, Off %X, Gran %X, Region %p, BankReg %p\n",
				  obj_desc->bank_field.start_field_bit_offset,
				  obj_desc->bank_field.base_byte_offset,
				  obj_desc->field.access_byte_width,
				  obj_desc->bank_field.region_obj,
				  obj_desc->bank_field.bank_obj));

		/*
                                                      
                                                
                                
   */
		second_desc = obj_desc->common.next_object;
		second_desc->extra.aml_start =
		    ACPI_CAST_PTR(union acpi_parse_object,
				  info->data_register_node)->named.data;
		second_desc->extra.aml_length =
		    ACPI_CAST_PTR(union acpi_parse_object,
				  info->data_register_node)->named.length;

		break;

	case ACPI_TYPE_LOCAL_INDEX_FIELD:

		/*                                  */

		obj_desc->index_field.index_obj =
		    acpi_ns_get_attached_object(info->register_node);
		obj_desc->index_field.data_obj =
		    acpi_ns_get_attached_object(info->data_register_node);

		if (!obj_desc->index_field.data_obj
		    || !obj_desc->index_field.index_obj) {
			ACPI_ERROR((AE_INFO,
				    "Null Index Object during field prep"));
			acpi_ut_delete_object_desc(obj_desc);
			return_ACPI_STATUS(AE_AML_INTERNAL);
		}

		/*                                                  */

		acpi_ut_add_reference(obj_desc->index_field.data_obj);
		acpi_ut_add_reference(obj_desc->index_field.index_obj);

		/*
                                             
    
                                                                      
                                                                
    
                                                                     
                                          
    
                                             
                                                      
                                                      
    
                                                 
                                             
                                                    
   */
		obj_desc->index_field.value =
		    (u32) ACPI_ROUND_DOWN(ACPI_DIV_8(info->field_bit_position),
					  obj_desc->index_field.
					  access_byte_width);

		ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
				  "IndexField: BitOff %X, Off %X, Value %X, Gran %X, Index %p, Data %p\n",
				  obj_desc->index_field.start_field_bit_offset,
				  obj_desc->index_field.base_byte_offset,
				  obj_desc->index_field.value,
				  obj_desc->field.access_byte_width,
				  obj_desc->index_field.index_obj,
				  obj_desc->index_field.data_obj));
		break;

	default:
		/*                                */
		break;
	}

	/*
                                                                     
                                                  
  */
	status = acpi_ns_attach_object(info->field_node, obj_desc,
				       acpi_ns_get_type(info->field_node));

	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
			  "Set NamedObj %p [%4.4s], ObjDesc %p\n",
			  info->field_node,
			  acpi_ut_get_node_name(info->field_node), obj_desc));

	/*                                      */

	acpi_ut_remove_reference(obj_desc);
	return_ACPI_STATUS(status);
}

//.........这里部分代码省略.........
        /* An additional reference for the attached objects */

        AcpiUtAddReference (ObjDesc->BankField.RegionObj);
        AcpiUtAddReference (ObjDesc->BankField.BankObj);

        ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
            "Bank Field: BitOff %X, Off %X, Gran %X, Region %p, BankReg %p\n",
            ObjDesc->BankField.StartFieldBitOffset,
            ObjDesc->BankField.BaseByteOffset,
            ObjDesc->Field.AccessByteWidth,
            ObjDesc->BankField.RegionObj,
            ObjDesc->BankField.BankObj));

        /*
         * Remember location in AML stream of the field unit
         * opcode and operands -- since the BankValue
         * operands must be evaluated.
         */
        SecondDesc = ObjDesc->Common.NextObject;
        SecondDesc->Extra.AmlStart = ACPI_CAST_PTR (ACPI_PARSE_OBJECT,
            Info->DataRegisterNode)->Named.Data;
        SecondDesc->Extra.AmlLength = ACPI_CAST_PTR (ACPI_PARSE_OBJECT,
            Info->DataRegisterNode)->Named.Length;

        break;

    case ACPI_TYPE_LOCAL_INDEX_FIELD:

        /* Get the Index and Data registers */

        ObjDesc->IndexField.IndexObj =
            AcpiNsGetAttachedObject (Info->RegisterNode);
        ObjDesc->IndexField.DataObj =
            AcpiNsGetAttachedObject (Info->DataRegisterNode);

        if (!ObjDesc->IndexField.DataObj || !ObjDesc->IndexField.IndexObj)
        {
            ACPI_ERROR ((AE_INFO, "Null Index Object during field prep"));
            AcpiUtDeleteObjectDesc (ObjDesc);
            return_ACPI_STATUS (AE_AML_INTERNAL);
        }

        /* An additional reference for the attached objects */

        AcpiUtAddReference (ObjDesc->IndexField.DataObj);
        AcpiUtAddReference (ObjDesc->IndexField.IndexObj);

        /*
         * April 2006: Changed to match MS behavior
         *
         * The value written to the Index register is the byte offset of the
         * target field in units of the granularity of the IndexField
         *
         * Previously, the value was calculated as an index in terms of the
         * width of the Data register, as below:
         *
         *      ObjDesc->IndexField.Value = (UINT32)
         *          (Info->FieldBitPosition / ACPI_MUL_8 (
         *              ObjDesc->Field.AccessByteWidth));
         *
         * February 2006: Tried value as a byte offset:
         *      ObjDesc->IndexField.Value = (UINT32)
         *          ACPI_DIV_8 (Info->FieldBitPosition);
         */
        ObjDesc->IndexField.Value = (UINT32) ACPI_ROUND_DOWN (
            ACPI_DIV_8 (Info->FieldBitPosition),
            ObjDesc->IndexField.AccessByteWidth);

        ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
            "IndexField: BitOff %X, Off %X, Value %X, Gran %X, Index %p, Data %p\n",
            ObjDesc->IndexField.StartFieldBitOffset,
            ObjDesc->IndexField.BaseByteOffset,
            ObjDesc->IndexField.Value,
            ObjDesc->Field.AccessByteWidth,
            ObjDesc->IndexField.IndexObj,
            ObjDesc->IndexField.DataObj));
        break;

    default:

        /* No other types should get here */

        break;
    }

    /*
     * Store the constructed descriptor (ObjDesc) into the parent Node,
     * preserving the current type of that NamedObj.
     */
    Status = AcpiNsAttachObject (Info->FieldNode, ObjDesc,
                AcpiNsGetType (Info->FieldNode));

    ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD, "Set NamedObj %p [%4.4s], ObjDesc %p\n",
        Info->FieldNode, AcpiUtGetNodeName (Info->FieldNode), ObjDesc));

    /* Remove local reference to the object */

    AcpiUtRemoveReference (ObjDesc);
    return_ACPI_STATUS (Status);
}

ACPI_STATUS
AcpiExPrepCommonFieldObject (
    ACPI_OPERAND_OBJECT     *ObjDesc,
    UINT8                   FieldFlags,
    UINT8                   FieldAttribute,
    UINT32                  FieldBitPosition,
    UINT32                  FieldBitLength)
{
    UINT32                  AccessBitWidth;
    UINT32                  ByteAlignment;
    UINT32                  NearestByteAddress;


    ACPI_FUNCTION_TRACE (ExPrepCommonFieldObject);


    /*
     * Note: the structure being initialized is the
     * ACPI_COMMON_FIELD_INFO;  No structure fields outside of the common
     * area are initialized by this procedure.
     */
    ObjDesc->CommonField.FieldFlags = FieldFlags;
    ObjDesc->CommonField.Attribute  = FieldAttribute;
    ObjDesc->CommonField.BitLength  = FieldBitLength;

    /*
     * Decode the access type so we can compute offsets. The access type gives
     * two pieces of information - the width of each field access and the
     * necessary ByteAlignment (address granularity) of the access.
     *
     * For AnyAcc, the AccessBitWidth is the largest width that is both
     * necessary and possible in an attempt to access the whole field in one
     * I/O operation. However, for AnyAcc, the ByteAlignment is always one
     * byte.
     *
     * For all Buffer Fields, the ByteAlignment is always one byte.
     *
     * For all other access types (Byte, Word, Dword, Qword), the Bitwidth is
     * the same (equivalent) as the ByteAlignment.
     */
    AccessBitWidth = AcpiExDecodeFieldAccess (ObjDesc, FieldFlags,
                        &ByteAlignment);
    if (!AccessBitWidth)
    {
        return_ACPI_STATUS (AE_AML_OPERAND_VALUE);
    }

    /* Setup width (access granularity) fields (values are: 1, 2, 4, 8) */

    ObjDesc->CommonField.AccessByteWidth = (UINT8)
        ACPI_DIV_8 (AccessBitWidth);

    /*
     * BaseByteOffset is the address of the start of the field within the
     * region. It is the byte address of the first *datum* (field-width data
     * unit) of the field. (i.e., the first datum that contains at least the
     * first *bit* of the field.)
     *
     * Note: ByteAlignment is always either equal to the AccessBitWidth or 8
     * (Byte access), and it defines the addressing granularity of the parent
     * region or buffer.
     */
    NearestByteAddress =
        ACPI_ROUND_BITS_DOWN_TO_BYTES (FieldBitPosition);
    ObjDesc->CommonField.BaseByteOffset = (UINT32)
        ACPI_ROUND_DOWN (NearestByteAddress, ByteAlignment);

    /*
     * StartFieldBitOffset is the offset of the first bit of the field within
     * a field datum.
     */
    ObjDesc->CommonField.StartFieldBitOffset = (UINT8)
        (FieldBitPosition - ACPI_MUL_8 (ObjDesc->CommonField.BaseByteOffset));

    return_ACPI_STATUS (AE_OK);
}

//.........这里部分代码省略.........

        if (FieldBitLength)
        {
            if (TagBitLength < FieldBitLength)
            {
                Message = ASL_MSG_TAG_SMALLER;
            }
            else if (TagBitLength > FieldBitLength)
            {
                Message = ASL_MSG_TAG_LARGER;
            }

            if (Message)
            {
                sprintf (AslGbl_MsgBuffer,
                    "Size mismatch, Tag: %u bit%s, Field: %u bit%s",
                    TagBitLength, (TagBitLength > 1) ? "s" : "",
                    FieldBitLength, (FieldBitLength > 1) ? "s" : "");

                AslError (ASL_WARNING, Message, Op, AslGbl_MsgBuffer);
            }
        }

        /* Convert the BitOffset to a ByteOffset for certain opcodes */

        switch (Op->Asl.Parent->Asl.AmlOpcode)
        {
        case AML_CREATE_BYTE_FIELD_OP:
        case AML_CREATE_WORD_FIELD_OP:
        case AML_CREATE_DWORD_FIELD_OP:
        case AML_CREATE_QWORD_FIELD_OP:
        case AML_INDEX_OP:

            Offset = ACPI_DIV_8 (Offset);
            break;

        default:

            break;
        }

        /* Now convert this node to an integer whose value is the field offset */

        Op->Asl.AmlLength = 0;
        Op->Asl.ParseOpcode = PARSEOP_INTEGER;
        Op->Asl.Value.Integer = (UINT64) Offset;
        Op->Asl.CompileFlags |= OP_IS_RESOURCE_FIELD;

        OpcGenerateAmlOpcode (Op);
    }

    /* 3) Check for a method invocation */

    else if ((((Op->Asl.ParseOpcode == PARSEOP_NAMESTRING) || (Op->Asl.ParseOpcode == PARSEOP_NAMESEG)) &&
                (Node->Type == ACPI_TYPE_METHOD) &&
                (Op->Asl.Parent) &&
                (Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_METHOD))   ||

                (Op->Asl.ParseOpcode == PARSEOP_METHODCALL))
    {
        /*
         * A reference to a method within one of these opcodes is not an
         * invocation of the method, it is simply a reference to the method.
         *
         * September 2016: Removed DeRefOf from this list
         */

acpi_status acpi_hw_write(u32 value, struct acpi_generic_address *reg)
{
	u64 address;
	u8 access_width;
	u32 bit_width;
	u8 bit_offset;
	u64 value64;
	u32 new_value32, old_value32;
	u8 index;
	acpi_status status;

	ACPI_FUNCTION_NAME(hw_write);

	/* Validate contents of the GAS register */

	status = acpi_hw_validate_register(reg, 32, &address);
	if (ACPI_FAILURE(status)) {
		return (status);
	}

	/* Convert access_width into number of bits based */

	access_width = acpi_hw_get_access_bit_width(reg, 32);
	bit_width = reg->bit_offset + reg->bit_width;
	bit_offset = reg->bit_offset;

	/*
	 * Two address spaces supported: Memory or IO. PCI_Config is
	 * not supported here because the GAS structure is insufficient
	 */
	index = 0;
	while (bit_width) {
		/*
		 * Use offset style bit reads because "Index * AccessWidth" is
		 * ensured to be less than 32-bits by acpi_hw_validate_register().
		 */
		new_value32 = ACPI_GET_BITS(&value, index * access_width,
					    ACPI_MASK_BITS_ABOVE_32
					    (access_width));

		if (bit_offset >= access_width) {
			bit_offset -= access_width;
		} else {
			/*
			 * Use offset style bit masks because access_width is ensured
			 * to be less than 32-bits by acpi_hw_validate_register() and
			 * bit_offset/bit_width is less than access_width here.
			 */
			if (bit_offset) {
				new_value32 &= ACPI_MASK_BITS_BELOW(bit_offset);
			}
			if (bit_width < access_width) {
				new_value32 &= ACPI_MASK_BITS_ABOVE(bit_width);
			}

			if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
				if (bit_offset || bit_width < access_width) {
					/*
					 * Read old values in order not to modify the bits that
					 * are beyond the register bit_width/bit_offset setting.
					 */
					status =
					    acpi_os_read_memory((acpi_physical_address)
								address +
								index *
								ACPI_DIV_8
								(access_width),
								&value64,
								access_width);
					old_value32 = (u32)value64;

					/*
					 * Use offset style bit masks because access_width is
					 * ensured to be less than 32-bits by
					 * acpi_hw_validate_register() and bit_offset/bit_width is
					 * less than access_width here.
					 */
					if (bit_offset) {
						old_value32 &=
						    ACPI_MASK_BITS_ABOVE
						    (bit_offset);
						bit_offset = 0;
					}
					if (bit_width < access_width) {
						old_value32 &=
						    ACPI_MASK_BITS_BELOW
						    (bit_width);
					}

					new_value32 |= old_value32;
				}

				value64 = (u64)new_value32;
				status =
				    acpi_os_write_memory((acpi_physical_address)
							 address +
							 index *
							 ACPI_DIV_8
							 (access_width),
							 value64, access_width);
//.........这里部分代码省略.........

acpi_status acpi_hw_write(u64 value, struct acpi_generic_address *reg)
{
	u64 address;
	u8 access_width;
	u32 bit_width;
	u8 bit_offset;
	u64 value64;
	u8 index;
	acpi_status status;

	ACPI_FUNCTION_NAME(hw_write);

	/* Validate contents of the GAS register */

	status = acpi_hw_validate_register(reg, 64, &address);
	if (ACPI_FAILURE(status)) {
		return (status);
	}

	/* Convert access_width into number of bits based */

	access_width = acpi_hw_get_access_bit_width(address, reg, 64);
	bit_width = reg->bit_offset + reg->bit_width;
	bit_offset = reg->bit_offset;

	/*
	 * Two address spaces supported: Memory or IO. PCI_Config is
	 * not supported here because the GAS structure is insufficient
	 */
	index = 0;
	while (bit_width) {
		/*
		 * Use offset style bit reads because "Index * AccessWidth" is
		 * ensured to be less than 64-bits by acpi_hw_validate_register().
		 */
		value64 = ACPI_GET_BITS(&value, index * access_width,
					ACPI_MASK_BITS_ABOVE_64(access_width));

		if (bit_offset >= access_width) {
			bit_offset -= access_width;
		} else {
			if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
				status =
				    acpi_os_write_memory((acpi_physical_address)
							 address +
							 index *
							 ACPI_DIV_8
							 (access_width),
							 value64, access_width);
			} else {	/* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */

				status = acpi_hw_write_port((acpi_io_address)
							    address +
							    index *
							    ACPI_DIV_8
							    (access_width),
							    (u32)value64,
							    access_width);
			}
		}

		/*
		 * Index * access_width is ensured to be less than 32-bits by
		 * acpi_hw_validate_register().
		 */
		bit_width -=
		    bit_width > access_width ? access_width : bit_width;
		index++;
	}

	ACPI_DEBUG_PRINT((ACPI_DB_IO,
			  "Wrote: %8.8X%8.8X width %2d   to %8.8X%8.8X (%s)\n",
			  ACPI_FORMAT_UINT64(value), access_width,
			  ACPI_FORMAT_UINT64(address),
			  acpi_ut_get_region_name(reg->space_id)));

	return (status);
}

static ACPI_STATUS
AcpiHwValidateIoRequest (
    ACPI_IO_ADDRESS         Address,
    UINT32                  BitWidth)
{
    UINT32                  i;
    UINT32                  ByteWidth;
    ACPI_IO_ADDRESS         LastAddress;
    const ACPI_PORT_INFO    *PortInfo;


    ACPI_FUNCTION_TRACE (HwValidateIoRequest);


    /* Supported widths are 8/16/32 */

    if ((BitWidth != 8) &&
        (BitWidth != 16) &&
        (BitWidth != 32))
    {
        ACPI_ERROR ((AE_INFO,
            "Bad BitWidth parameter: %8.8X", BitWidth));
        return (AE_BAD_PARAMETER);
    }

    PortInfo = AcpiProtectedPorts;
    ByteWidth = ACPI_DIV_8 (BitWidth);
    LastAddress = Address + ByteWidth - 1;

    ACPI_DEBUG_PRINT ((ACPI_DB_IO, "Address %8.8X%8.8X LastAddress %8.8X%8.8X Length %X",
        ACPI_FORMAT_UINT64 (Address), ACPI_FORMAT_UINT64 (LastAddress),
        ByteWidth));

    /* Maximum 16-bit address in I/O space */

    if (LastAddress > ACPI_UINT16_MAX)
    {
        ACPI_ERROR ((AE_INFO,
            "Illegal I/O port address/length above 64K: %8.8X%8.8X/0x%X",
            ACPI_FORMAT_UINT64 (Address), ByteWidth));
        return_ACPI_STATUS (AE_LIMIT);
    }

    /* Exit if requested address is not within the protected port table */

    if (Address > AcpiProtectedPorts[ACPI_PORT_INFO_ENTRIES - 1].End)
    {
        return_ACPI_STATUS (AE_OK);
    }

    /* Check request against the list of protected I/O ports */

    for (i = 0; i < ACPI_PORT_INFO_ENTRIES; i++, PortInfo++)
    {
        /*
         * Check if the requested address range will write to a reserved
         * port. Four cases to consider:
         *
         * 1) Address range is contained completely in the port address range
         * 2) Address range overlaps port range at the port range start
         * 3) Address range overlaps port range at the port range end
         * 4) Address range completely encompasses the port range
         */
        if ((Address <= PortInfo->End) && (LastAddress >= PortInfo->Start))
        {
            /* Port illegality may depend on the _OSI calls made by the BIOS */

            if (AcpiGbl_OsiData >= PortInfo->OsiDependency)
            {
                ACPI_DEBUG_PRINT ((ACPI_DB_IO,
                    "Denied AML access to port 0x%8.8X%8.8X/%X (%s 0x%.4X-0x%.4X)",
                    ACPI_FORMAT_UINT64 (Address), ByteWidth, PortInfo->Name,
                    PortInfo->Start, PortInfo->End));

                return_ACPI_STATUS (AE_AML_ILLEGAL_ADDRESS);
            }
        }

        /* Finished if address range ends before the end of this port */

        if (LastAddress <= PortInfo->End)
        {
            break;
        }
    }

    return_ACPI_STATUS (AE_OK);
}

ACPI_STATUS
AcpiHwWrite (
    UINT32                  Value,
    ACPI_GENERIC_ADDRESS    *Reg)
{
    UINT64                  Address;
    UINT8                   AccessWidth;
    UINT32                  BitWidth;
    UINT8                   BitOffset;
    UINT64                  Value64;
    UINT32                  NewValue32, OldValue32;
    UINT8                   Index;
    ACPI_STATUS             Status;


    ACPI_FUNCTION_NAME (HwWrite);


    /* Validate contents of the GAS register */

    Status = AcpiHwValidateRegister (Reg, 32, &Address);
    if (ACPI_FAILURE (Status))
    {
        return (Status);
    }

    /* Convert AccessWidth into number of bits based */

    AccessWidth = Reg->AccessWidth ? Reg->AccessWidth : 1;
    AccessWidth = 1 << (AccessWidth + 2);
    BitWidth = ACPI_ROUND_UP (Reg->BitOffset + Reg->BitWidth, AccessWidth);
    BitOffset = Reg->BitOffset;

    /*
     * Two address spaces supported: Memory or IO. PCI_Config is
     * not supported here because the GAS structure is insufficient
     */
    Index = 0;
    while (BitWidth)
    {
        NewValue32 = ACPI_GET_BITS (&Value, (Index * AccessWidth),
            ((1 << AccessWidth) - 1));

        if (BitOffset > AccessWidth)
        {
            BitOffset -= AccessWidth;
        }
        else
        {
            if (BitOffset)
            {
                NewValue32 &= ACPI_MASK_BITS_BELOW (BitOffset);
            }

            if (BitWidth < AccessWidth)
            {
                NewValue32 &= ACPI_MASK_BITS_ABOVE (BitWidth);
            }

            if (Reg->SpaceId == ACPI_ADR_SPACE_SYSTEM_MEMORY)
            {
                if (BitOffset || BitWidth < AccessWidth)
                {
                    /*
                     * Read old values in order not to modify the bits that
                     * are beyond the register BitWidth/BitOffset setting.
                     */
                    Status = AcpiOsReadMemory ((ACPI_PHYSICAL_ADDRESS)
                        Address + Index * ACPI_DIV_8 (AccessWidth),
                        &Value64, AccessWidth);
                    OldValue32 = (UINT32) Value64;

                    if (BitOffset)
                    {
                        OldValue32 &= ACPI_MASK_BITS_ABOVE (BitOffset + 1);
                        BitOffset = 0;
                    }

                    if (BitWidth < AccessWidth)
                    {
                        OldValue32 &= ACPI_MASK_BITS_BELOW (BitWidth - 1);
                    }

                    NewValue32 |= OldValue32;
                }

                Value64 = (UINT64) NewValue32;
                Status = AcpiOsWriteMemory ((ACPI_PHYSICAL_ADDRESS)
                    Address + Index * ACPI_DIV_8 (AccessWidth),
                    Value64, AccessWidth);
            }
            else /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
            {
                if (BitOffset || BitWidth < AccessWidth)
                {
                    /*
                     * Read old values in order not to modify the bits that
                     * are beyond the register BitWidth/BitOffset setting.
                     */
                    Status = AcpiHwReadPort ((ACPI_IO_ADDRESS)
//.........这里部分代码省略.........

ACPI_STATUS
AcpiHwRead (
    UINT32                  *Value,
    ACPI_GENERIC_ADDRESS    *Reg)
{
    UINT64                  Address;
    UINT8                   AccessWidth;
    UINT32                  BitWidth;
    UINT8                   BitOffset;
    UINT64                  Value64;
    UINT32                  Value32;
    UINT8                   Index;
    ACPI_STATUS             Status;


    ACPI_FUNCTION_NAME (HwRead);


    /* Validate contents of the GAS register */

    Status = AcpiHwValidateRegister (Reg, 32, &Address);
    if (ACPI_FAILURE (Status))
    {
        return (Status);
    }

    /*
     * Initialize entire 32-bit return value to zero, convert AccessWidth
     * into number of bits based
     */
    *Value = 0;
    AccessWidth = Reg->AccessWidth ? Reg->AccessWidth : 1;
    AccessWidth = 1 << (AccessWidth + 2);
    BitWidth = ACPI_ROUND_UP (Reg->BitOffset + Reg->BitWidth, AccessWidth);
    BitOffset = Reg->BitOffset;

    /*
     * Two address spaces supported: Memory or IO. PCI_Config is
     * not supported here because the GAS structure is insufficient
     */
    Index = 0;
    while (BitWidth)
    {
        if (BitOffset > AccessWidth)
        {
            Value32 = 0;
            BitOffset -= AccessWidth;
        }
        else
        {
            if (Reg->SpaceId == ACPI_ADR_SPACE_SYSTEM_MEMORY)
            {
                Status = AcpiOsReadMemory ((ACPI_PHYSICAL_ADDRESS)
                    Address + Index * ACPI_DIV_8 (AccessWidth),
                    &Value64, AccessWidth);
                Value32 = (UINT32) Value64;
            }
            else /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
            {
                Status = AcpiHwReadPort ((ACPI_IO_ADDRESS)
                    Address + Index * ACPI_DIV_8 (AccessWidth),
                    &Value32, AccessWidth);
            }

            if (BitOffset)
            {
                Value32 &= ACPI_MASK_BITS_BELOW (BitOffset);
                BitOffset = 0;
            }
            if (BitWidth < AccessWidth)
            {
                Value32 &= ACPI_MASK_BITS_ABOVE (BitWidth);
            }
        }

        ACPI_SET_BITS (Value, Index * AccessWidth,
            ((1 << AccessWidth) - 1), Value32);

        BitWidth -= BitWidth > AccessWidth ? AccessWidth : BitWidth;
        Index++;
    }

    ACPI_DEBUG_PRINT ((ACPI_DB_IO,
        "Read:  %8.8X width %2d from %8.8X%8.8X (%s)\n",
        *Value, AccessWidth, ACPI_FORMAT_UINT64 (Address),
        AcpiUtGetRegionName (Reg->SpaceId)));

    return (Status);
}

//.........这里部分代码省略.........

		ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
				  "Bank Field: BitOff %X, Off %X, Gran %X, Region %p, BankReg %p\n",
				  obj_desc->bank_field.start_field_bit_offset,
				  obj_desc->bank_field.base_byte_offset,
				  obj_desc->field.access_byte_width,
				  obj_desc->bank_field.region_obj,
				  obj_desc->bank_field.bank_obj));

		/*
		 * Remember location in AML stream of the field unit
		 * opcode and operands -- since the bank_value
		 * operands must be evaluated.
		 */
		second_desc = obj_desc->common.next_object;
		second_desc->extra.aml_start =
		    ACPI_CAST_PTR(union acpi_parse_object,
				  info->data_register_node)->named.data;
		second_desc->extra.aml_length =
		    ACPI_CAST_PTR(union acpi_parse_object,
				  info->data_register_node)->named.length;

		break;

	case ACPI_TYPE_LOCAL_INDEX_FIELD:

		/* Get the Index and Data registers */

		obj_desc->index_field.index_obj =
		    acpi_ns_get_attached_object(info->register_node);
		obj_desc->index_field.data_obj =
		    acpi_ns_get_attached_object(info->data_register_node);

		if (!obj_desc->index_field.data_obj
		    || !obj_desc->index_field.index_obj) {
			ACPI_ERROR((AE_INFO,
				    "Null Index Object during field prep"));
			acpi_ut_delete_object_desc(obj_desc);
			return_ACPI_STATUS(AE_AML_INTERNAL);
		}

		/* An additional reference for the attached objects */

		acpi_ut_add_reference(obj_desc->index_field.data_obj);
		acpi_ut_add_reference(obj_desc->index_field.index_obj);

		/*
		 * April 2006: Changed to match MS behavior
		 *
		 * The value written to the Index register is the byte offset of the
		 * target field in units of the granularity of the index_field
		 *
		 * Previously, the value was calculated as an index in terms of the
		 * width of the Data register, as below:
		 *
		 *      obj_desc->index_field.Value = (u32)
		 *          (Info->field_bit_position / ACPI_MUL_8 (
		 *              obj_desc->Field.access_byte_width));
		 *
		 * February 2006: Tried value as a byte offset:
		 *      obj_desc->index_field.Value = (u32)
		 *          ACPI_DIV_8 (Info->field_bit_position);
		 */
		obj_desc->index_field.value =
		    (u32) ACPI_ROUND_DOWN(ACPI_DIV_8(info->field_bit_position),
					  obj_desc->index_field.
					  access_byte_width);

		ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
				  "IndexField: BitOff %X, Off %X, Value %X, Gran %X, Index %p, Data %p\n",
				  obj_desc->index_field.start_field_bit_offset,
				  obj_desc->index_field.base_byte_offset,
				  obj_desc->index_field.value,
				  obj_desc->field.access_byte_width,
				  obj_desc->index_field.index_obj,
				  obj_desc->index_field.data_obj));
		break;

	default:
		/* No other types should get here */
		break;
	}

	/*
	 * Store the constructed descriptor (obj_desc) into the parent Node,
	 * preserving the current type of that named_obj.
	 */
	status = acpi_ns_attach_object(info->field_node, obj_desc,
				       acpi_ns_get_type(info->field_node));

	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
			  "Set NamedObj %p [%4.4s], ObjDesc %p\n",
			  info->field_node,
			  acpi_ut_get_node_name(info->field_node), obj_desc));

	/* Remove local reference to the object */

	acpi_ut_remove_reference(obj_desc);
	return_ACPI_STATUS(status);
}