FreeBSD/Linux Kernel Cross Reference
sys/iokit/IOKit/IOMultiMemoryDescriptor.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 _IOMULTIMEMORYDESCRIPTOR_H
    #define _IOMULTIMEMORYDESCRIPTOR_H
    
    #include <IOKit/IOMemoryDescriptor.h>
    
    /*! @class IOMultiMemoryDescriptor : public IOMemoryDescriptor
        @abstract The IOMultiMemoryDescriptor object describes a memory area made up of several other IOMemoryDescriptors.
        @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. */
    
    class IOMultiMemoryDescriptor : public IOMemoryDescriptor
    {
        OSDeclareDefaultStructors(IOMultiMemoryDescriptor);
    
    protected:
    
        IOMemoryDescriptor ** _descriptors;
        UInt32                _descriptorsCount;
        bool                  _descriptorsIsAllocated;
    
        virtual void free();
    
    public:
    
    /*! @function withDescriptors
        @abstract Create an IOMultiMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
        @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.
        @param descriptors An array of IOMemoryDescriptors which make up the memory to be described.
        @param withCount The object count for the descriptors array.
        @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.
        @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.
        @result The created IOMultiMemoryDescriptor on success, to be released by the caller, or zero on failure. */
    
        static IOMultiMemoryDescriptor * withDescriptors(
                                      IOMemoryDescriptor ** descriptors,
                                      UInt32                withCount,
                                      IODirection           withDirection,
                                      bool                  asReference = false );
    
    /*! @function withDescriptors
        @abstract Initialize an IOMultiMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
        @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.
        @param descriptors An array of IOMemoryDescriptors which make up the memory to be described.
        @param withCount The object count for the descriptors array.
        @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.
        @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.
        @result The created IOMultiMemoryDescriptor on success, to be released by the caller, or zero on failure. */
    
        virtual bool initWithDescriptors(
                                      IOMemoryDescriptor ** descriptors,
                                      UInt32                withCount,
                                      IODirection           withDirection,
                                      bool                  asReference = false );
    
    /*! @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 needn't called for non-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 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 /* !_IOMULTIMEMORYDESCRIPTOR_H */

Cache object: 3b3f3220af2196b616a6466803e8dfcd