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