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, |
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26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
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 | |
39 | class IOInterleavedMemoryDescriptor : public IOMemoryDescriptor |
40 | { |
41 | OSDeclareDefaultStructors(IOInterleavedMemoryDescriptor); |
42 | |
43 | protected: |
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 | |
54 | public: |
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 | |