This is xnu-8019. See this file in:
/*
 * Copyright (c) 2019-2019 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

#if !__IIG
#if KERNEL
#include <IOKit/IOMemoryDescriptor.h>
#endif
#endif

#ifndef _IOKIT_UIOMEMORYMAP_H
#define _IOKIT_UIOMEMORYMAP_H

#include <DriverKit/OSObject.iig>

struct _IOMemoryMapPrivateState {
	uint64_t length;
	uint64_t offset;
	uint64_t options;
	uint64_t address;
};

/*!
 * @class IOMemoryMap
 *
 * @abstract
 * IOMemoryMap describes a memory mapping created with IOMemoryDescriptor::CreateMapping()
 *
 * @discussion
 * To allocate memory for I/O or sharing, use IOBufferMemoryDescriptor::Create()
 * Methods in this class are used for memory that was supplied as a parameter.
 */

class KERNEL IOMemoryMap : public OSObject
{
public:

	virtual bool
	init() override;

	virtual void
	free() override;
	
    /*!
     * @brief       Obtain the address of the memory mapping.
     * @return      Address.
     */
	uint64_t
	GetAddress() LOCALONLY;

    /*!
     * @brief       Obtain the length of the memory mapping.
     * @return      Length.
     */
	uint64_t
	GetLength() LOCALONLY;

    /*!
     * @brief       Obtain the offset of the memory mapping.
     * @return      Offset.
     */
	uint64_t
	GetOffset() LOCALONLY;
};

class EXTENDS (IOMemoryMap) IOMemoryMapPrivate
{
	virtual kern_return_t
	_CopyState(
		_IOMemoryMapPrivateState * state);
};

#endif /* ! _IOKIT_UIOMEMORYMAP_H */