/* * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. The rights granted to you under the License * may not be used to create, or enable the creation or redistribution of, * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ #ifndef _IOINTERLEAVEDMEMORYDESCRIPTOR_H #define _IOINTERLEAVEDMEMORYDESCRIPTOR_H #include <IOKit/IOMemoryDescriptor.h> /*! @class IOInterleavedMemoryDescriptor : public IOMemoryDescriptor @abstract The IOInterleavedMemoryDescriptor object describes a memory area made up of portions of several other IOMemoryDescriptors. @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. */ class IOInterleavedMemoryDescriptor : public IOMemoryDescriptor { OSDeclareDefaultStructors(IOInterleavedMemoryDescriptor); protected: IOByteCount _descriptorCapacity; UInt32 _descriptorCount; IOMemoryDescriptor ** _descriptors; IOByteCount * _descriptorOffsets; IOByteCount * _descriptorLengths; bool _descriptorPrepared; virtual void free(); public: /*! @function withCapacity @abstract Create an IOInterleavedMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors. @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. @param capacity The maximum number of IOMemoryDescriptors that may be subsequently added to this IOInterleavedMemoryDescriptor. @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. @result The created IOInterleavedMemoryDescriptor on success, to be released by the caller, or zero on failure. */ static IOInterleavedMemoryDescriptor * withCapacity( IOByteCount capacity, IODirection direction); /*! @function initWithCapacity @abstract Initialize an IOInterleavedMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors. @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. @param capacity The maximum number of IOMemoryDescriptors that may be subsequently added to this IOInterleavedMemoryDescriptor. @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. @result The created IOInterleavedMemoryDescriptor on success, to be released by the caller, or zero on failure. */ virtual bool initWithCapacity( IOByteCount capacity, IODirection direction ); /*! @function clearMemoryDescriptors @abstract Clear all of the IOMemoryDescriptors currently contained in and reset the IOInterleavedMemoryDescriptor. @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. @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. */ virtual void clearMemoryDescriptors( IODirection direction = kIODirectionNone ); /*! @function setMemoryDescriptor @abstract Add a portion of an IOMemoryDescriptor to the IOInterleavedMemoryDescriptor. @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. @param descriptor An IOMemoryDescriptor to be added to the IOInterleavedMemoryDescriptor. Its direction must be compatible with that of the IOInterleavedMemoryDescriptor. @param offset The offset into the IOMemoryDescriptor of the portion that will be added to the virtualized buffer. @param length The length of the portion of the IOMemoryDescriptor to be added to the virtualized buffer. @result Returns true the portion was successfully added. */ virtual bool setMemoryDescriptor( IOMemoryDescriptor * descriptor, IOByteCount offset, IOByteCount length ); /*! @function getPhysicalSegment @abstract Break a memory descriptor into its physically contiguous segments. @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. @param offset A byte offset into the memory whose physical address to return. @param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset. @result A physical address, or zero if the offset is beyond the length of the memory. */ virtual addr64_t getPhysicalSegment( IOByteCount offset, IOByteCount * length, IOOptionBits options = 0 ); /*! @function prepare @abstract Prepare the memory for an I/O transfer. @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. @param forDirection The direction of the I/O to be performed, or kIODirectionNone for the direction specified by the memory descriptor. @result An IOReturn code. */ virtual IOReturn prepare(IODirection forDirection = kIODirectionNone); /*! @function complete @abstract Complete processing of the memory after an I/O transfer finishes. @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. @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor. @result An IOReturn code. */ virtual IOReturn complete(IODirection forDirection = kIODirectionNone); }; #endif /* !_IOINTERLEAVEDMEMORYDESCRIPTOR_H */