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 38 class IOSubMemoryDescriptor : public IOMemoryDescriptor 39 { 40 OSDeclareDefaultStructors(IOSubMemoryDescriptor); 41 42 protected: 43 IOMemoryDescriptor * _parent; 44 IOByteCount _start; 45 46 virtual void free(); 47 48 public: 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 */ 110