iokit/IOKit/IOInterleavedMemoryDescriptor.h

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
   3  *
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   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
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   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,
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  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
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  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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  23  * Please see the License for the specific language governing rights and
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  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     UInt32                _descriptorCapacity;
  45     UInt32                _descriptorCount;
  46     IOMemoryDescriptor ** _descriptors;
  47     IOByteCount         * _descriptorOffsets;
  48     IOByteCount         * _descriptorLengths;
  49     bool                  _descriptorPrepared;
  50
  51     virtual void free();
  52
  53     /*
  54      * These methods are not supported under this subclass.
  55      */
  56
  57     virtual bool initWithAddress( void *      address,       /* not supported */
  58                                   IOByteCount withLength,
  59                                   IODirection withDirection );
  60
  61     virtual bool initWithAddress( vm_address_t address,      /* not supported */
  62                                   IOByteCount  withLength,
  63                                   IODirection  withDirection,
  64                                   task_t       withTask );
  65
  66     virtual bool initWithPhysicalAddress(
  67                                   IOPhysicalAddress address, /* not supported */
  68                                   IOByteCount       withLength,
  69                                   IODirection       withDirection );
  70
  71     virtual bool initWithPhysicalRanges(
  72                                   IOPhysicalRange * ranges,  /* not supported */
  73                                   UInt32            withCount,
  74                                   IODirection       withDirection,
  75                                   bool              asReference = false );
  76
  77     virtual bool initWithRanges(  IOVirtualRange * ranges,   /* not supported */
  78                                   UInt32           withCount,
  79                                   IODirection      withDirection,
  80                                   task_t           withTask,
  81                                   bool             asReference = false );
  82
  83     virtual void * getVirtualSegment( IOByteCount   offset,  /* not supported */
  84                                       IOByteCount * length );
  85
  86     IOMemoryDescriptor::withAddress;                         /* not supported */
  87     IOMemoryDescriptor::withPhysicalAddress;                 /* not supported */
  88     IOMemoryDescriptor::withPhysicalRanges;                  /* not supported */
  89     IOMemoryDescriptor::withRanges;                          /* not supported */
  90     IOMemoryDescriptor::withSubRange;                        /* not supported */
  91
  92 public:
  93
  94 /*! @function withCapacity
  95     @abstract Create an IOInterleavedMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
  96     @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.
  97     @param capacity The maximum number of IOMemoryDescriptors that may be subsequently added to this IOInterleavedMemoryDescriptor.
  98     @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.
  99     @result The created IOInterleavedMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 100
 101     static IOInterleavedMemoryDescriptor * withCapacity( UInt32                capacity,
 102                                                          IODirection           direction);
 103
 104 /*! @function initWithCapacity
 105     @abstract Initialize an IOInterleavedMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
 106     @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.
 107     @param capacity The maximum number of IOMemoryDescriptors that may be subsequently added to this IOInterleavedMemoryDescriptor.
 108     @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.
 109     @result The created IOInterleavedMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 110
 111     virtual bool initWithCapacity( UInt32                capacity,
 112                                    IODirection           direction );
 113
 114 /*! @function clearMemoryDescriptors
 115     @abstract Clear all of the IOMemoryDescriptors currently contained in and reset the IOInterleavedMemoryDescriptor.
 116     @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.
 117     @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. */
 118
 119     virtual void clearMemoryDescriptors( IODirection direction = kIODirectionNone );
 120
 121 /*! @function setMemoryDescriptor
 122     @abstract Add a portion of an IOMemoryDescriptor to the IOInterleavedMemoryDescriptor.
 123     @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.
 124     @param descriptor An IOMemoryDescriptor to be added to the IOInterleavedMemoryDescriptor.  Its direction must be compatible with that of the IOInterleavedMemoryDescriptor.
 125     @param offset The offset into the IOMemoryDescriptor of the portion that will be added to the virtualized buffer.
 126     @param length The length of the portion of the IOMemoryDescriptor to be added to the virtualized buffer.
 127     @result Returns true the portion was successfully added. */
 128
 129     virtual bool setMemoryDescriptor( IOMemoryDescriptor * descriptor,
 130                                       IOByteCount offset,
 131                                       IOByteCount length );
 132
 133 /*! @function getPhysicalSegment
 134     @abstract Break a memory descriptor into its physically contiguous segments.
 135     @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.
 136     @param offset A byte offset into the memory whose physical address to return.
 137     @param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset.
 138     @result A physical address, or zero if the offset is beyond the length of the memory. */
 139
 140     virtual IOPhysicalAddress getPhysicalSegment( IOByteCount   offset,
 141                                                   IOByteCount * length );
 142
 143     virtual addr64_t getPhysicalSegment64(        IOByteCount   offset,
 144                                                   IOByteCount * length );
 145
 146 /*! @function prepare
 147     @abstract Prepare the memory for an I/O transfer.
 148     @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.
 149     @param forDirection The direction of the I/O to be performed, or kIODirectionNone for the direction specified by the memory descriptor.
 150     @result An IOReturn code. */
 151
 152     virtual IOReturn prepare(IODirection forDirection = kIODirectionNone);
 153
 154 /*! @function complete
 155     @abstract Complete processing of the memory after an I/O transfer finishes.
 156     @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.
 157     @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
 158     @result An IOReturn code. */
 159
 160     virtual IOReturn complete(IODirection forDirection = kIODirectionNone);
 161
 162     virtual IOPhysicalAddress getSourceSegment(IOByteCount offset,
 163                                                IOByteCount * length);
 164 };
 165
 166 #endif /* !_IOINTERLEAVEDMEMORYDESCRIPTOR_H */