iokit/IOKit/IOMultiMemoryDescriptor.h

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
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  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25
  26 #ifndef _IOMULTIMEMORYDESCRIPTOR_H
  27 #define _IOMULTIMEMORYDESCRIPTOR_H
  28
  29 #include <IOKit/IOMemoryDescriptor.h>
  30
  31 /*! @class IOMultiMemoryDescriptor : public IOMemoryDescriptor
  32     @abstract The IOMultiMemoryDescriptor object describes a memory area made up of several other IOMemoryDescriptors.
  33     @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. */
  34
  35 class IOMultiMemoryDescriptor : public IOMemoryDescriptor
  36 {
  37     OSDeclareDefaultStructors(IOMultiMemoryDescriptor);
  38
  39 protected:
  40
  41     IOMemoryDescriptor ** _descriptors;
  42     UInt32                _descriptorsCount;
  43     bool                  _descriptorsIsAllocated;
  44
  45     virtual void free();
  46
  47     /*
  48      * These methods are not supported under this subclass.
  49      */
  50
  51     virtual bool initWithAddress( void *      address,       /* not supported */
  52                                   IOByteCount withLength,
  53                                   IODirection withDirection );
  54
  55     virtual bool initWithAddress( vm_address_t address,      /* not supported */
  56                                   IOByteCount  withLength,
  57                                   IODirection  withDirection,
  58                                   task_t       withTask );
  59
  60     virtual bool initWithPhysicalAddress(
  61                                   IOPhysicalAddress address, /* not supported */
  62                                   IOByteCount       withLength,
  63                                   IODirection       withDirection );
  64
  65     virtual bool initWithPhysicalRanges(
  66                                   IOPhysicalRange * ranges,  /* not supported */
  67                                   UInt32            withCount,
  68                                   IODirection       withDirection,
  69                                   bool              asReference = false );
  70
  71     virtual bool initWithRanges(  IOVirtualRange * ranges,   /* not supported */
  72                                   UInt32           withCount,
  73                                   IODirection      withDirection,
  74                                   task_t           withTask,
  75                                   bool             asReference = false );
  76
  77     virtual void * getVirtualSegment( IOByteCount   offset,  /* not supported */
  78                                       IOByteCount * length );
  79
  80     IOMemoryDescriptor::withAddress;                         /* not supported */
  81     IOMemoryDescriptor::withPhysicalAddress;                 /* not supported */
  82     IOMemoryDescriptor::withPhysicalRanges;                  /* not supported */
  83     IOMemoryDescriptor::withRanges;                          /* not supported */
  84     IOMemoryDescriptor::withSubRange;                        /* not supported */
  85
  86 public:
  87
  88 /*! @function withDescriptors
  89     @abstract Create an IOMultiMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
  90     @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.
  91     @param descriptors An array of IOMemoryDescriptors which make up the memory to be described.
  92     @param withCount The object count for the descriptors array.
  93     @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.
  94     @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.
  95     @result The created IOMultiMemoryDescriptor on success, to be released by the caller, or zero on failure. */
  96
  97     static IOMultiMemoryDescriptor * withDescriptors(
  98                                   IOMemoryDescriptor ** descriptors,
  99                                   UInt32                withCount,
 100                                   IODirection           withDirection,
 101                                   bool                  asReference = false );
 102
 103 /*! @function withDescriptors
 104     @abstract Initialize an IOMultiMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
 105     @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.
 106     @param descriptors An array of IOMemoryDescriptors which make up the memory to be described.
 107     @param withCount The object count for the descriptors array.
 108     @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.
 109     @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.
 110     @result The created IOMultiMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 111
 112     virtual bool initWithDescriptors(
 113                                   IOMemoryDescriptor ** descriptors,
 114                                   UInt32                withCount,
 115                                   IODirection           withDirection,
 116                                   bool                  asReference = false );
 117
 118 /*! @function getPhysicalAddress
 119     @abstract Return the physical address of the first byte in the memory.
 120     @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.
 121     @result A physical address. */
 122
 123     virtual IOPhysicalAddress getPhysicalSegment( IOByteCount   offset,
 124                                                   IOByteCount * length );
 125
 126 /*! @function prepare
 127     @abstract Prepare the memory for an I/O transfer.
 128     @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.
 129     @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
 130     @result An IOReturn code. */
 131
 132     virtual IOReturn prepare(IODirection forDirection = kIODirectionNone);
 133
 134 /*! @function complete
 135     @abstract Complete processing of the memory after an I/O transfer finishes.
 136     @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.
 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 complete(IODirection forDirection = kIODirectionNone);
 141
 142 /*! @function readBytes
 143     @abstract Copy data from the memory descriptor's buffer to the specified buffer.
 144     @discussion This method copies data from the memory descriptor's memory at the given offset, to the caller's buffer.
 145     @param offset A byte offset into the memory descriptor's memory.
 146     @param bytes The caller supplied buffer to copy the data to.
 147     @param withLength The length of the data to copy.
 148     @result The number of bytes copied, zero will be returned if the specified offset is beyond the length of the descriptor. */
 149
 150     virtual IOByteCount readBytes( IOByteCount offset,
 151                                    void *      bytes,
 152                                    IOByteCount withLength );
 153
 154 /*! @function writeBytes
 155     @abstract Copy data to the memory descriptor's buffer from the specified buffer.
 156     @discussion This method copies data to the memory descriptor's memory at the given offset, from the caller's buffer.
 157     @param offset A byte offset into the memory descriptor's memory.
 158     @param bytes The caller supplied buffer to copy the data from.
 159     @param withLength The length of the data to copy.
 160     @result The number of bytes copied, zero will be returned if the specified offset is beyond the length of the descriptor. */
 161
 162     virtual IOByteCount writeBytes( IOByteCount  offset,
 163                                     const void * bytes,
 164                                     IOByteCount  withLength );
 165
 166     virtual IOPhysicalAddress getSourceSegment(IOByteCount offset,
 167                                                IOByteCount * length);
 168 };
 169
 170 #endif /* !_IOMULTIMEMORYDESCRIPTOR_H */