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,␊ |
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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 */␊ |
123 | |