[apple/xnu.git] / iokit / IOKit / IOMultiMemoryDescriptor.h

/*
 * Copyright (c) 1998-2000 Apple Computer, 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@
 */

#ifndef _IOMULTIMEMORYDESCRIPTOR_H
#define _IOMULTIMEMORYDESCRIPTOR_H

#include <IOKit/IOMemoryDescriptor.h>

/*! @class IOMultiMemoryDescriptor : public IOMemoryDescriptor
    @abstract The IOMultiMemoryDescriptor object describes a memory area made up of several other IOMemoryDescriptors.
    @discussion The IOMultiMemoryDescriptor object represents multiple ranges of memory, specified as an ordered list of IOMemoryDescriptors.  The descriptors are chained end-to-end to make up a single contiguous buffer. */

class IOMultiMemoryDescriptor : public IOMemoryDescriptor
{
    OSDeclareDefaultStructors(IOMultiMemoryDescriptor);

protected:

    IOMemoryDescriptor ** _descriptors;
    UInt32                _descriptorsCount;
    bool                  _descriptorsIsAllocated;

    virtual void free();

public:

/*! @function withDescriptors
    @abstract Create an IOMultiMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
    @discussion This method creates and initializes an IOMultiMemoryDescriptor for memory consisting 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.  Passing the descriptor array as a reference will avoid an extra allocation.
    @param descriptors An array of IOMemoryDescriptors which make up the memory to be described.
    @param withCount The object count for the descriptors array.
    @param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
    @param asReference If false, the IOMultiMemoryDescriptor object will make a copy of the descriptors array, otherwise, the array will be used in situ, avoiding an extra allocation.
    @result The created IOMultiMemoryDescriptor on success, to be released by the caller, or zero on failure. */

    static IOMultiMemoryDescriptor * withDescriptors(
                                  IOMemoryDescriptor ** descriptors,
                                  UInt32                withCount,
                                  IODirection           withDirection,
                                  bool                  asReference = false );

/*! @function withDescriptors
    @abstract Initialize an IOMultiMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
    @discussion This method initializes an IOMultiMemoryDescriptor for memory consisting 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.  Passing the descriptor array as a reference will avoid an extra allocation.
    @param descriptors An array of IOMemoryDescriptors which make up the memory to be described.
    @param withCount The object count for the descriptors array.
    @param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
    @param asReference If false, the IOMultiMemoryDescriptor object will make a copy of the descriptors array, otherwise, the array will be used in situ, avoiding an extra allocation.
    @result The created IOMultiMemoryDescriptor on success, to be released by the caller, or zero on failure. */

    virtual bool initWithDescriptors(
                                  IOMemoryDescriptor ** descriptors,
                                  UInt32                withCount,
                                  IODirection           withDirection,
                                  bool                  asReference = false );

/*! @function getPhysicalSegment
    @abstract Break a memory descriptor into its physically contiguous segments.
    @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.
    @param offset A byte offset into the memory whose physical address to return.
    @param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset.
    @result A physical address, or zero if the offset is beyond the length of the memory. */

    virtual addr64_t getPhysicalSegment( IOByteCount   offset,
                                         IOByteCount * length,
                                         IOOptionBits  options = 0 );

/*! @function prepare
    @abstract Prepare the memory for an I/O transfer.
    @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 needn't called for non-pageable memory.
    @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
    @result An IOReturn code. */

    virtual IOReturn prepare(IODirection forDirection = kIODirectionNone);

/*! @function complete
    @abstract Complete processing of the memory after an I/O transfer finishes.
    @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.
    @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
    @result An IOReturn code. */

    virtual IOReturn complete(IODirection forDirection = kIODirectionNone);
};

#endif /* !_IOMULTIMEMORYDESCRIPTOR_H */
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
	3	*
2d21ac55	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b	5	*
2d21ac55 A	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.
8f6c56a5	14	*
2d21ac55 A	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
8f6c56a5 A	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
8f6c56a5 A	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55 A	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.
8f6c56a5	25	*
2d21ac55	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b A	27	*/
	28
	29	#ifndef _IOMULTIMEMORYDESCRIPTOR_H
	30	#define _IOMULTIMEMORYDESCRIPTOR_H
	31
	32	#include <IOKit/IOMemoryDescriptor.h>
	33
	34	/*! @class IOMultiMemoryDescriptor : public IOMemoryDescriptor
	35	@abstract The IOMultiMemoryDescriptor object describes a memory area made up of several other IOMemoryDescriptors.
	36	@discussion The IOMultiMemoryDescriptor object represents multiple ranges of memory, specified as an ordered list of IOMemoryDescriptors. The descriptors are chained end-to-end to make up a single contiguous buffer. */
	37
	38	class IOMultiMemoryDescriptor : public IOMemoryDescriptor
	39	{
	40	OSDeclareDefaultStructors(IOMultiMemoryDescriptor);
	41
	42	protected:
	43
	44	IOMemoryDescriptor ** _descriptors;
	45	UInt32 _descriptorsCount;
	46	bool _descriptorsIsAllocated;
	47
	48	virtual void free();
	49
1c79356b A	50	public:
	51
	52	/*! @function withDescriptors
	53	@abstract Create an IOMultiMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
	54	@discussion This method creates and initializes an IOMultiMemoryDescriptor for memory consisting 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. Passing the descriptor array as a reference will avoid an extra allocation.
	55	@param descriptors An array of IOMemoryDescriptors which make up the memory to be described.
	56	@param withCount The object count for the descriptors array.
	57	@param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
	58	@param asReference If false, the IOMultiMemoryDescriptor object will make a copy of the descriptors array, otherwise, the array will be used in situ, avoiding an extra allocation.
	59	@result The created IOMultiMemoryDescriptor on success, to be released by the caller, or zero on failure. */
	60
	61	static IOMultiMemoryDescriptor * withDescriptors(
	62	IOMemoryDescriptor ** descriptors,
	63	UInt32 withCount,
	64	IODirection withDirection,
	65	bool asReference = false );
	66
	67	/*! @function withDescriptors
	68	@abstract Initialize an IOMultiMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
	69	@discussion This method initializes an IOMultiMemoryDescriptor for memory consisting 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. Passing the descriptor array as a reference will avoid an extra allocation.
	70	@param descriptors An array of IOMemoryDescriptors which make up the memory to be described.
	71	@param withCount The object count for the descriptors array.
	72	@param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
	73	@param asReference If false, the IOMultiMemoryDescriptor object will make a copy of the descriptors array, otherwise, the array will be used in situ, avoiding an extra allocation.
	74	@result The created IOMultiMemoryDescriptor on success, to be released by the caller, or zero on failure. */
	75
	76	virtual bool initWithDescriptors(
	77	IOMemoryDescriptor ** descriptors,
	78	UInt32 withCount,
	79	IODirection withDirection,
	80	bool asReference = false );
	81
b0d623f7 A	82	/*! @function getPhysicalSegment
	83	@abstract Break a memory descriptor into its physically contiguous segments.
	84	@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.
	85	@param offset A byte offset into the memory whose physical address to return.
	86	@param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset.
	87	@result A physical address, or zero if the offset is beyond the length of the memory. */
1c79356b	88
b0d623f7 A	89	virtual addr64_t getPhysicalSegment( IOByteCount offset,
	90	IOByteCount * length,
	91	IOOptionBits options = 0 );
0c530ab8	92
1c79356b A	93	/*! @function prepare
	94	@abstract Prepare the memory for an I/O transfer.
	95	@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 needn't called for non-pageable memory.
	96	@param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
	97	@result An IOReturn code. */
	98
	99	virtual IOReturn prepare(IODirection forDirection = kIODirectionNone);
	100
	101	/*! @function complete
	102	@abstract Complete processing of the memory after an I/O transfer finishes.
	103	@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.
	104	@param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
	105	@result An IOReturn code. */
	106
	107	virtual IOReturn complete(IODirection forDirection = kIODirectionNone);
1c79356b A	108	};
	109
	110	#endif /* !_IOMULTIMEMORYDESCRIPTOR_H */