IOMultiMemoryDescriptor.h
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 _IOMULTIMEMORYDESCRIPTOR_H 30 #define _IOMULTIMEMORYDESCRIPTOR_H 31 32 #include <IOKit/IOMemoryDescriptor.h> 33 #include <libkern/c++/OSPtr.h> 34 35 /*! @class IOMultiMemoryDescriptor : public IOMemoryDescriptor 36 * @abstract The IOMultiMemoryDescriptor object describes a memory area made up of several other IOMemoryDescriptors. 37 * @discussion The IOMultiMemoryDescriptor object represents multiple ranges of memory, specified as an ordered list of IOMemoryDescriptors. The descriptors are chained end-to-end to make up a single contiguous buffer. */ 38 39 class IOMultiMemoryDescriptor : public IOMemoryDescriptor 40 { 41 OSDeclareDefaultStructors(IOMultiMemoryDescriptor); 42 43 protected: 44 45 IOMemoryDescriptor ** _descriptors; 46 UInt32 _descriptorsCount; 47 bool _descriptorsIsAllocated; 48 49 virtual void free() APPLE_KEXT_OVERRIDE; 50 51 public: 52 53 /*! @function withDescriptors 54 * @abstract Create an IOMultiMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors. 55 * @discussion This method creates and initializes an IOMultiMemoryDescriptor for memory consisting 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. Passing the descriptor array as a reference will avoid an extra allocation. 56 * @param descriptors An array of IOMemoryDescriptors which make up the memory to be described. 57 * @param withCount The object count for the descriptors array. 58 * @param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures. 59 * @param asReference If false, the IOMultiMemoryDescriptor object will make a copy of the descriptors array, otherwise, the array will be used in situ, avoiding an extra allocation. 60 * @result The created IOMultiMemoryDescriptor on success, to be released by the caller, or zero on failure. */ 61 62 static OSPtr<IOMultiMemoryDescriptor> withDescriptors( 63 IOMemoryDescriptor ** descriptors, 64 UInt32 withCount, 65 IODirection withDirection, 66 bool asReference = false ); 67 68 /*! @function withDescriptors 69 * @abstract Initialize an IOMultiMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors. 70 * @discussion This method initializes an IOMultiMemoryDescriptor for memory consisting 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. Passing the descriptor array as a reference will avoid an extra allocation. 71 * @param descriptors An array of IOMemoryDescriptors which make up the memory to be described. 72 * @param withCount The object count for the descriptors array. 73 * @param withDirection An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures. 74 * @param asReference If false, the IOMultiMemoryDescriptor object will make a copy of the descriptors array, otherwise, the array will be used in situ, avoiding an extra allocation. 75 * @result The created IOMultiMemoryDescriptor on success, to be released by the caller, or zero on failure. */ 76 77 virtual bool initWithDescriptors( 78 IOMemoryDescriptor ** descriptors, 79 UInt32 withCount, 80 IODirection withDirection, 81 bool asReference = false ); 82 83 /*! @function getPhysicalSegment 84 * @abstract Break a memory descriptor into its physically contiguous segments. 85 * @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. 86 * @param offset A byte offset into the memory whose physical address to return. 87 * @param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset. 88 * @result A physical address, or zero if the offset is beyond the length of the memory. */ 89 90 virtual addr64_t getPhysicalSegment( IOByteCount offset, 91 IOByteCount * length, 92 IOOptionBits options = 0 ) APPLE_KEXT_OVERRIDE; 93 94 /*! @function prepare 95 * @abstract Prepare the memory for an I/O transfer. 96 * @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 needn't called for non-pageable memory. 97 * @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor. 98 * @result An IOReturn code. */ 99 100 virtual IOReturn prepare(IODirection forDirection = kIODirectionNone) APPLE_KEXT_OVERRIDE; 101 102 /*! @function complete 103 * @abstract Complete processing of the memory after an I/O transfer finishes. 104 * @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. 105 * @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor. 106 * @result An IOReturn code. */ 107 108 virtual IOReturn complete(IODirection forDirection = kIODirectionNone) APPLE_KEXT_OVERRIDE; 109 110 virtual IOReturn setPurgeable(IOOptionBits newState, IOOptionBits * oldState) APPLE_KEXT_OVERRIDE; 111 112 IOReturn setOwnership(task_t newOwner, int newLedgerTag, IOOptionBits newOptions); 113 114 /*! @function getPageCounts 115 * @abstract Retrieve the number of resident and/or dirty pages encompassed by an IOMemoryDescriptor. 116 * @discussion This method returns the number of resident and/or dirty pages encompassed by an IOMemoryDescriptor. 117 * @param residentPageCount - If non-null, a pointer to a byte count that will return the number of resident pages encompassed by this IOMemoryDescriptor. 118 * @param dirtyPageCount - If non-null, a pointer to a byte count that will return the number of dirty pages encompassed by this IOMemoryDescriptor. 119 * @result An IOReturn code. */ 120 121 IOReturn getPageCounts(IOByteCount * residentPageCount, 122 IOByteCount * dirtyPageCount); 123 124 virtual uint64_t getPreparationID( void ) APPLE_KEXT_OVERRIDE; 125 126 #define IOMULTIMEMORYDESCRIPTOR_SUPPORTS_GETPAGECOUNTS 1 127 128 private: 129 virtual IOReturn doMap(vm_map_t addressMap, 130 IOVirtualAddress * atAddress, 131 IOOptionBits options, 132 IOByteCount sourceOffset = 0, 133 IOByteCount length = 0 ) APPLE_KEXT_OVERRIDE; 134 }; 135 136 #endif /* !_IOMULTIMEMORYDESCRIPTOR_H */