FreeBSD/Linux Kernel Cross Reference
sys/iokit/IOKit/IOInterleavedMemoryDescriptor.h

     /*
      * 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 */

Cache object: 06e2baeab6ecfa33b89c2e958a937985