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 _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