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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 _IOSUBMEMORYDESCRIPTOR_H
30#define _IOSUBMEMORYDESCRIPTOR_H
31
32#include <IOKit/IOMemoryDescriptor.h>
33
34/*! @class IOSubMemoryDescriptor : public IOMemoryDescriptor
35 @abstract The IOSubMemoryDescriptor object describes a memory area made up of a portion of another IOMemoryDescriptor.
36 @discussion The IOSubMemoryDescriptor object represents a subrange of memory, specified as a portion of another IOMemoryDescriptor. */
37
38class IOSubMemoryDescriptor : public IOMemoryDescriptor
39{
40 OSDeclareDefaultStructors(IOSubMemoryDescriptor);
41
42protected:
43 IOMemoryDescriptor * _parent;
44 IOByteCount _start;
45
46 virtual void free();
47
48public:
49/*! @function withSubRange
50 @abstract Create an IOMemoryDescriptor to describe a subrange of an existing descriptor.
51 @discussion This method creates and initializes an IOMemoryDescriptor for memory consisting of a subrange of the specified memory descriptor. The parent memory descriptor is retained by the new descriptor.
52 @param of The parent IOMemoryDescriptor of which a subrange is to be used for the new descriptor, which will be retained by the subrange IOMemoryDescriptor.
53 @param offset A byte offset into the parent memory descriptor's memory.
54 @param length The length of the subrange.
55 @param options
56 kIOMemoryDirectionMask (options:direction) This nibble indicates the I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
57 @result The created IOMemoryDescriptor on success, to be released by the caller, or zero on failure. */
58
59 static IOSubMemoryDescriptor * withSubRange(IOMemoryDescriptor *of,
60 IOByteCount offset,
61 IOByteCount length,
62 IOOptionBits options);
63
64 /*
65 * Initialize or reinitialize an IOSubMemoryDescriptor to describe
66 * a subrange of an existing descriptor.
67 *
68 * An IOSubMemoryDescriptor can be re-used by calling initSubRange
69 * again on an existing instance -- note that this behavior is not
70 * commonly supported in other IOKit classes, although it is here.
71 */
72 virtual bool initSubRange( IOMemoryDescriptor * parent,
73 IOByteCount offset, IOByteCount length,
74 IODirection withDirection );
75
76 /*
77 * IOMemoryDescriptor required methods
78 */
79
80 virtual addr64_t getPhysicalSegment( IOByteCount offset,
81 IOByteCount * length,
82 IOOptionBits options = 0 );
83
84 virtual IOReturn prepare(IODirection forDirection = kIODirectionNone);
85
86 virtual IOReturn complete(IODirection forDirection = kIODirectionNone);
87
88#ifdef __LP64__
89 virtual
90#endif /* __LP64__ */
91 IOReturn redirect( task_t safeTask, bool redirect );
92
93 virtual IOReturn setPurgeable( IOOptionBits newState,
94 IOOptionBits * oldState );
95
96 // support map() on kIOMemoryTypeVirtual without prepare()
97 virtual IOMemoryMap * makeMapping(
98 IOMemoryDescriptor * owner,
99 task_t intoTask,
100 IOVirtualAddress atAddress,
101 IOOptionBits options,
102 IOByteCount offset,
103 IOByteCount length );
104
105 virtual uint64_t getPreparationID( void );
106
107};
108
109#endif /* !_IOSUBMEMORYDESCRIPTOR_H */