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	1	/*
	2	* Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
	25	*
	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
	27	*/
	28
	29	#ifndef _IOINTERLEAVEDMEMORYDESCRIPTOR_H
	30	#define _IOINTERLEAVEDMEMORYDESCRIPTOR_H
	31
	32	#include <IOKit/IOMemoryDescriptor.h>
	33
	34	/*! @class IOInterleavedMemoryDescriptor : public IOMemoryDescriptor
	35	@abstract The IOInterleavedMemoryDescriptor object describes a memory area made up of portions of several other IOMemoryDescriptors.
	36	@discussion The IOInterleavedMemoryDescriptor object represents interleaved ranges of memory, specified as an ordered list of portions of individual IOMemoryDescriptors. The portions are chained end-to-end to make up a single contiguous buffer. */
	37
	38	class IOInterleavedMemoryDescriptor : public IOMemoryDescriptor
	39	{
	40	OSDeclareDefaultStructors(IOInterleavedMemoryDescriptor);
	41
	42	protected:
	43
	44	IOByteCount _descriptorCapacity;
	45	UInt32 _descriptorCount;
	46	IOMemoryDescriptor ** _descriptors;
	47	IOByteCount * _descriptorOffsets;
	48	IOByteCount * _descriptorLengths;
	49	bool _descriptorPrepared;
	50
	51	virtual void free();
	52
	53	public:
	54
	55	/*! @function withCapacity
	56	@abstract Create an IOInterleavedMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
	57	@discussion This method creates and initializes an IOInterleavedMemoryDescriptor for memory consisting of portions of a number of other IOMemoryDescriptors, chained end-to-end (in the order they appear in the array) to represent a single contiguous memory buffer.
	58	@param capacity The maximum number of IOMemoryDescriptors that may be subsequently added to this IOInterleavedMemoryDescriptor.
	59	@param direction An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
	60	@result The created IOInterleavedMemoryDescriptor on success, to be released by the caller, or zero on failure. */
	61
	62	static IOInterleavedMemoryDescriptor * withCapacity( IOByteCount capacity,
	63	IODirection direction);
	64
	65	/*! @function initWithCapacity
	66	@abstract Initialize an IOInterleavedMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
	67	@discussion This method initializes an IOInterleavedMemoryDescriptor for memory consisting of portions of a number of other IOMemoryDescriptors, chained end-to-end (in the order they appear in the array) to represent a single contiguous memory buffer.
	68	@param capacity The maximum number of IOMemoryDescriptors that may be subsequently added to this IOInterleavedMemoryDescriptor.
	69	@param direction An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
	70	@result The created IOInterleavedMemoryDescriptor on success, to be released by the caller, or zero on failure. */
	71
	72	virtual bool initWithCapacity( IOByteCount capacity,
	73	IODirection direction );
	74
	75	/*! @function clearMemoryDescriptors
	76	@abstract Clear all of the IOMemoryDescriptors currently contained in and reset the IOInterleavedMemoryDescriptor.
	77	@discussion Clears each IOMemoryDescriptor by completing (if needed) and releasing. The IOInterleavedMemoryDescriptor is then reset and may accept new descriptors up to the capacity specified when it was created.
	78	@param direction An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures. */
	79
	80	virtual void clearMemoryDescriptors( IODirection direction = kIODirectionNone );
	81
	82	/*! @function setMemoryDescriptor
	83	@abstract Add a portion of an IOMemoryDescriptor to the IOInterleavedMemoryDescriptor.
	84	@discussion This method adds the portion of an IOMemoryDescriptor described by the offset and length parameters to the end of the IOInterleavedMemoryDescriptor. A single IOMemoryDescriptor may be added as many times as there is room for it. The offset and length must describe a portion entirely within the IOMemoryDescriptor.
	85	@param descriptor An IOMemoryDescriptor to be added to the IOInterleavedMemoryDescriptor. Its direction must be compatible with that of the IOInterleavedMemoryDescriptor.
	86	@param offset The offset into the IOMemoryDescriptor of the portion that will be added to the virtualized buffer.
	87	@param length The length of the portion of the IOMemoryDescriptor to be added to the virtualized buffer.
	88	@result Returns true the portion was successfully added. */
	89
	90	virtual bool setMemoryDescriptor( IOMemoryDescriptor * descriptor,
	91	IOByteCount offset,
	92	IOByteCount length );
	93
	94	/*! @function getPhysicalSegment
	95	@abstract Break a memory descriptor into its physically contiguous segments.
	96	@discussion This method returns the physical address of the byte at the given offset into the memory, and optionally the length of the physically contiguous segment from that offset.
	97	@param offset A byte offset into the memory whose physical address to return.
	98	@param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset.
	99	@result A physical address, or zero if the offset is beyond the length of the memory. */
	100
	101	virtual addr64_t getPhysicalSegment( IOByteCount offset,
	102	IOByteCount * length,
	103	IOOptionBits options = 0 );
	104
	105	/*! @function prepare
	106	@abstract Prepare the memory for an I/O transfer.
	107	@discussion This involves paging in the memory, if necessary, and wiring it down for the duration of the transfer. The complete() method completes the processing of the memory after the I/O transfer finishes. This method need not called for non-pageable memory.
	108	@param forDirection The direction of the I/O to be performed, or kIODirectionNone for the direction specified by the memory descriptor.
	109	@result An IOReturn code. */
	110
	111	virtual IOReturn prepare(IODirection forDirection = kIODirectionNone);
	112
	113	/*! @function complete
	114	@abstract Complete processing of the memory after an I/O transfer finishes.
	115	@discussion This method should not be called unless a prepare was previously issued; the prepare() and complete() must occur in pairs, before and after an I/O transfer involving pageable memory.
	116	@param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
	117	@result An IOReturn code. */
	118
	119	virtual IOReturn complete(IODirection forDirection = kIODirectionNone);
	120	};
	121
	122	#endif /* !_IOINTERLEAVEDMEMORYDESCRIPTOR_H */