xref: /xnu-11417.140.69/iokit/IOKit/IODeviceMemory.h (revision 43a90889846e00bfb5cf1d255cdc0a701a1e05a4)
1 /*
2  * Copyright (c) 1998-2019 Apple 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
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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
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15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
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18  * The Original Code and all software distributed under the License are
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20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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27  */
28 /*
29  * Copyright (c) 1998 Apple Computer, Inc.  All rights reserved.
30  *
31  * HISTORY
32  *
33  */
34 
35 #ifndef _IOKIT_IODEVICEMEMORY_H
36 #define _IOKIT_IODEVICEMEMORY_H
37 
38 #include <IOKit/IOMemoryDescriptor.h>
39 #include <libkern/c++/OSPtr.h>
40 
41 /*! @class IODeviceMemory
42  *   @abstract An IOMemoryDescriptor used for device physical memory ranges.
43  *   @discussion The IODeviceMemory class is a simple subclass of IOMemoryDescriptor that uses its methods to describe a single range of physical memory on a device. IODeviceMemory objects are usually looked up with IOService or IOPCIDevice accessors, and are created by memory-mapped bus families. IODeviceMemory implements only some factory methods in addition to the methods of IOMemoryDescriptor.
44  */
45 
46 class IODeviceMemory : public IOMemoryDescriptor
47 {
48 	OSDeclareDefaultStructors(IODeviceMemory);
49 
50 public:
51 
52 /*! @struct InitElement
53  *   @field start First physical address in the range.
54  *   @field length Length of the range.
55  *   @field tag 32-bit value not interpreted by IODeviceMemory or IOMemoryDescriptor, for use by the bus family. */
56 
57 	struct InitElement {
58 		IOPhysicalAddress       start;
59 		IOPhysicalLength        length;
60 		IOOptionBits            tag;
61 	};
62 
63 /*! @function arrayFromList
64  *   @abstract Constructs an OSArray of IODeviceMemory instances, each describing one physical range, and a tag value.
65  *   @discussion This method creates IODeviceMemory instances for each physical range passed in an IODeviceMemory::InitElement array. Each element consists of a physical address, length and tag value for the IODeviceMemory. The instances are returned as a created OSArray.
66  *   @param list An array of IODeviceMemory::InitElement structures.
67  *   @param count The number of elements in the list.
68  *   @result Returns a created OSArray of IODeviceMemory objects, to be released by the caller, or zero on failure. */
69 
70 	static OSPtr<OSArray>             arrayFromList(
71 		InitElement             list[],
72 		IOItemCount             count );
73 
74 /*! @function withRange
75  *   @abstract Constructs an IODeviceMemory instance, describing one physical range.
76  *   @discussion This method creates an IODeviceMemory instance for one physical range passed as a physical address and length. It just calls IOMemoryDescriptor::withPhysicalAddress.
77  *   @param start The physical address of the first byte in the memory.
78  *   @param length The length of memory.
79  *   @result Returns the created IODeviceMemory on success, to be released by the caller, or zero on failure. */
80 
81 	static OSPtr<IODeviceMemory>      withRange(
82 		IOPhysicalAddress       start,
83 		IOPhysicalLength        length );
84 
85 /*! @function withSubRange
86  *   @abstract Constructs an IODeviceMemory instance, describing a subset of an existing IODeviceMemory range.
87  *   @discussion This method creates an IODeviceMemory instance for a subset of an existing IODeviceMemory range, passed as a physical address offset and length. It just calls IOMemoryDescriptor::withSubRange.
88  *   @param of The parent IODeviceMemory of which a subrange is to be used for the new descriptor, which will be retained by the subrange IODeviceMemory.
89  *   @param offset A byte offset into the parent's memory.
90  *   @param length The length of the subrange.
91  *   @result Returns the created IODeviceMemory on success, to be released by the caller, or zero on failure. */
92 
93 	static OSPtr<IODeviceMemory>      withSubRange(
94 		IODeviceMemory *        of,
95 		IOPhysicalAddress       offset,
96 		IOPhysicalLength        length );
97 };
98 
99 #endif /* ! _IOKIT_IODEVICEMEMORY_H */
100