iokit/IOKit/IOMultiMemoryDescriptor.h

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
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   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
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  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
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  20  * The Original Code and all software distributed under the License are
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  30
  31 #ifndef _IOMULTIMEMORYDESCRIPTOR_H
  32 #define _IOMULTIMEMORYDESCRIPTOR_H
  33
  34 #include <IOKit/IOMemoryDescriptor.h>
  35
  36 /*! @class IOMultiMemoryDescriptor : public IOMemoryDescriptor
  37     @abstract The IOMultiMemoryDescriptor object describes a memory area made up of several other IOMemoryDescriptors.
  38     @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. */
  39
  40 class IOMultiMemoryDescriptor : public IOMemoryDescriptor
  41 {
  42     OSDeclareDefaultStructors(IOMultiMemoryDescriptor);
  43
  44 protected:
  45
  46     IOMemoryDescriptor ** _descriptors;
  47     UInt32                _descriptorsCount;
  48     bool                  _descriptorsIsAllocated;
  49
  50     virtual void free();
  51
  52     /*
  53      * These methods are not supported under this subclass.
  54      */
  55
  56     virtual bool initWithAddress( void *      address,       /* not supported */
  57                                   IOByteCount withLength,
  58                                   IODirection withDirection );
  59
  60     virtual bool initWithAddress( vm_address_t address,      /* not supported */
  61                                   IOByteCount  withLength,
  62                                   IODirection  withDirection,
  63                                   task_t       withTask );
  64
  65     virtual bool initWithPhysicalAddress(
  66                                   IOPhysicalAddress address, /* not supported */
  67                                   IOByteCount       withLength,
  68                                   IODirection       withDirection );
  69
  70     virtual bool initWithPhysicalRanges(
  71                                   IOPhysicalRange * ranges,  /* not supported */
  72                                   UInt32            withCount,
  73                                   IODirection       withDirection,
  74                                   bool              asReference = false );
  75
  76     virtual bool initWithRanges(  IOVirtualRange * ranges,   /* not supported */
  77                                   UInt32           withCount,
  78                                   IODirection      withDirection,
  79                                   task_t           withTask,
  80                                   bool             asReference = false );
  81
  82     virtual void * getVirtualSegment( IOByteCount   offset,  /* not supported */
  83                                       IOByteCount * length );
  84
  85     IOMemoryDescriptor::withAddress;                         /* not supported */
  86     IOMemoryDescriptor::withPhysicalAddress;                 /* not supported */
  87     IOMemoryDescriptor::withPhysicalRanges;                  /* not supported */
  88     IOMemoryDescriptor::withRanges;                          /* not supported */
  89     IOMemoryDescriptor::withSubRange;                        /* not supported */
  90
  91 public:
  92
  93 /*! @function withDescriptors
  94     @abstract Create an IOMultiMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
  95     @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.
  96     @param descriptors An array of IOMemoryDescriptors which make up the memory to be described.
  97     @param withCount The object count for the descriptors array.
  98     @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.
  99     @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.
 100     @result The created IOMultiMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 101
 102     static IOMultiMemoryDescriptor * withDescriptors(
 103                                   IOMemoryDescriptor ** descriptors,
 104                                   UInt32                withCount,
 105                                   IODirection           withDirection,
 106                                   bool                  asReference = false );
 107
 108 /*! @function withDescriptors
 109     @abstract Initialize an IOMultiMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
 110     @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.
 111     @param descriptors An array of IOMemoryDescriptors which make up the memory to be described.
 112     @param withCount The object count for the descriptors array.
 113     @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.
 114     @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.
 115     @result The created IOMultiMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 116
 117     virtual bool initWithDescriptors(
 118                                   IOMemoryDescriptor ** descriptors,
 119                                   UInt32                withCount,
 120                                   IODirection           withDirection,
 121                                   bool                  asReference = false );
 122
 123 /*! @function getPhysicalAddress
 124     @abstract Return the physical address of the first byte in the memory.
 125     @discussion This method returns the physical address of the  first byte in the memory. It is most useful on memory known to be physically contiguous.
 126     @result A physical address. */
 127
 128     virtual IOPhysicalAddress getPhysicalSegment( IOByteCount   offset,
 129                                                   IOByteCount * length );
 130
 131 #if !(defined(__ppc__) && defined(KPI_10_4_0_PPC_COMPAT))
 132     virtual addr64_t getPhysicalSegment64(        IOByteCount   offset,
 133                                                   IOByteCount * length );
 134 #endif
 135
 136 /*! @function prepare
 137     @abstract Prepare the memory for an I/O transfer.
 138     @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.
 139     @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
 140     @result An IOReturn code. */
 141
 142     virtual IOReturn prepare(IODirection forDirection = kIODirectionNone);
 143
 144 /*! @function complete
 145     @abstract Complete processing of the memory after an I/O transfer finishes.
 146     @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.
 147     @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
 148     @result An IOReturn code. */
 149
 150     virtual IOReturn complete(IODirection forDirection = kIODirectionNone);
 151
 152 /*! @function readBytes
 153     @abstract Copy data from the memory descriptor's buffer to the specified buffer.
 154     @discussion This method copies data from the memory descriptor's memory at the given offset, to the caller's buffer.
 155     @param offset A byte offset into the memory descriptor's memory.
 156     @param bytes The caller supplied buffer to copy the data to.
 157     @param withLength The length of the data to copy.
 158     @result The number of bytes copied, zero will be returned if the specified offset is beyond the length of the descriptor. */
 159
 160     virtual IOByteCount readBytes( IOByteCount offset,
 161                                    void *      bytes,
 162                                    IOByteCount withLength );
 163
 164 /*! @function writeBytes
 165     @abstract Copy data to the memory descriptor's buffer from the specified buffer.
 166     @discussion This method copies data to the memory descriptor's memory at the given offset, from the caller's buffer.
 167     @param offset A byte offset into the memory descriptor's memory.
 168     @param bytes The caller supplied buffer to copy the data from.
 169     @param withLength The length of the data to copy.
 170     @result The number of bytes copied, zero will be returned if the specified offset is beyond the length of the descriptor. */
 171
 172     virtual IOByteCount writeBytes( IOByteCount  offset,
 173                                     const void * bytes,
 174                                     IOByteCount  withLength );
 175
 176     virtual IOPhysicalAddress getSourceSegment(IOByteCount offset,
 177                                                IOByteCount * length);
 178 };
 179
 180 #endif /* !_IOMULTIMEMORYDESCRIPTOR_H */