1/*
2 * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
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27 */
28
29#ifndef _IOINTERLEAVEDMEMORYDESCRIPTOR_H
30#define _IOINTERLEAVEDMEMORYDESCRIPTOR_H
31
32#include <IOKit/IOMemoryDescriptor.h>
33#include <libkern/c++/OSPtr.h>
34
35/*! @class IOInterleavedMemoryDescriptor : public IOMemoryDescriptor
36 * @abstract The IOInterleavedMemoryDescriptor object describes a memory area made up of portions of several other IOMemoryDescriptors.
37 * @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. */
38
39class IOInterleavedMemoryDescriptor : public IOMemoryDescriptor
40{
41 OSDeclareDefaultStructors(IOInterleavedMemoryDescriptor);
42
43protected:
44
45 IOByteCount _descriptorCapacity;
46 UInt32 _descriptorCount;
47 IOMemoryDescriptor ** _descriptors;
48 IOByteCount * _descriptorOffsets;
49 IOByteCount * _descriptorLengths;
50 bool _descriptorPrepared;
51
52 virtual void free() APPLE_KEXT_OVERRIDE;
53
54public:
55
56/*! @function withCapacity
57 * @abstract Create an IOInterleavedMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
58 * @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.
59 * @param capacity The maximum number of IOMemoryDescriptors that may be subsequently added to this IOInterleavedMemoryDescriptor.
60 * @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.
61 * @result The created IOInterleavedMemoryDescriptor on success, to be released by the caller, or zero on failure. */
62
63 static OSPtr<IOInterleavedMemoryDescriptor> withCapacity( IOByteCount capacity,
64 IODirection direction);
65
66/*! @function initWithCapacity
67 * @abstract Initialize an IOInterleavedMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
68 * @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.
69 * @param capacity The maximum number of IOMemoryDescriptors that may be subsequently added to this IOInterleavedMemoryDescriptor.
70 * @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.
71 * @result The created IOInterleavedMemoryDescriptor on success, to be released by the caller, or zero on failure. */
72
73 virtual bool initWithCapacity( IOByteCount capacity,
74 IODirection direction );
75
76/*! @function clearMemoryDescriptors
77 * @abstract Clear all of the IOMemoryDescriptors currently contained in and reset the IOInterleavedMemoryDescriptor.
78 * @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.
79 * @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. */
80
81 virtual void clearMemoryDescriptors( IODirection direction = kIODirectionNone );
82
83/*! @function setMemoryDescriptor
84 * @abstract Add a portion of an IOMemoryDescriptor to the IOInterleavedMemoryDescriptor.
85 * @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.
86 * @param descriptor An IOMemoryDescriptor to be added to the IOInterleavedMemoryDescriptor. Its direction must be compatible with that of the IOInterleavedMemoryDescriptor.
87 * @param offset The offset into the IOMemoryDescriptor of the portion that will be added to the virtualized buffer.
88 * @param length The length of the portion of the IOMemoryDescriptor to be added to the virtualized buffer.
89 * @result Returns true the portion was successfully added. */
90
91 virtual bool setMemoryDescriptor( IOMemoryDescriptor * descriptor,
92 IOByteCount offset,
93 IOByteCount length );
94
95/*! @function getPhysicalSegment
96 * @abstract Break a memory descriptor into its physically contiguous segments.
97 * @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.
98 * @param offset A byte offset into the memory whose physical address to return.
99 * @param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset.
100 * @result A physical address, or zero if the offset is beyond the length of the memory. */
101
102 virtual addr64_t getPhysicalSegment( IOByteCount offset,
103 IOByteCount * length,
104 IOOptionBits options = 0 ) APPLE_KEXT_OVERRIDE;
105
106/*! @function prepare
107 * @abstract Prepare the memory for an I/O transfer.
108 * @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.
109 * @param forDirection The direction of the I/O to be performed, or kIODirectionNone for the direction specified by the memory descriptor.
110 * @result An IOReturn code. */
111
112 virtual IOReturn prepare(IODirection forDirection = kIODirectionNone) APPLE_KEXT_OVERRIDE;
113
114/*! @function complete
115 * @abstract Complete processing of the memory after an I/O transfer finishes.
116 * @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.
117 * @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
118 * @result An IOReturn code. */
119
120 virtual IOReturn complete(IODirection forDirection = kIODirectionNone) APPLE_KEXT_OVERRIDE;
121};
122
123#endif /* !_IOINTERLEAVEDMEMORYDESCRIPTOR_H */
124