iokit/IOKit/IOMultiMemoryDescriptor.h

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #ifndef _IOMULTIMEMORYDESCRIPTOR_H
  25 #define _IOMULTIMEMORYDESCRIPTOR_H
  26
  27 #include <IOKit/IOMemoryDescriptor.h>
  28
  29 /*! @class IOMultiMemoryDescriptor : public IOMemoryDescriptor
  30     @abstract The IOMultiMemoryDescriptor object describes a memory area made up of several other IOMemoryDescriptors.
  31     @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. */
  32
  33 class IOMultiMemoryDescriptor : public IOMemoryDescriptor
  34 {
  35     OSDeclareDefaultStructors(IOMultiMemoryDescriptor);
  36
  37 protected:
  38
  39     IOMemoryDescriptor ** _descriptors;
  40     UInt32                _descriptorsCount;
  41     bool                  _descriptorsIsAllocated;
  42
  43     virtual void free();
  44
  45     /*
  46      * These methods are not supported under this subclass.
  47      */
  48
  49     virtual bool initWithAddress( void *      address,       /* not supported */
  50                                   IOByteCount withLength,
  51                                   IODirection withDirection );
  52
  53     virtual bool initWithAddress( vm_address_t address,      /* not supported */
  54                                   IOByteCount  withLength,
  55                                   IODirection  withDirection,
  56                                   task_t       withTask );
  57
  58     virtual bool initWithPhysicalAddress(
  59                                   IOPhysicalAddress address, /* not supported */
  60                                   IOByteCount       withLength,
  61                                   IODirection       withDirection );
  62
  63     virtual bool initWithPhysicalRanges(
  64                                   IOPhysicalRange * ranges,  /* not supported */
  65                                   UInt32            withCount,
  66                                   IODirection       withDirection,
  67                                   bool              asReference = false );
  68
  69     virtual bool initWithRanges(  IOVirtualRange * ranges,   /* not supported */
  70                                   UInt32           withCount,
  71                                   IODirection      withDirection,
  72                                   task_t           withTask,
  73                                   bool             asReference = false );
  74
  75     virtual void * getVirtualSegment( IOByteCount   offset,  /* not supported */
  76                                       IOByteCount * length );
  77
  78     IOMemoryDescriptor::withAddress;                         /* not supported */
  79     IOMemoryDescriptor::withPhysicalAddress;                 /* not supported */
  80     IOMemoryDescriptor::withPhysicalRanges;                  /* not supported */
  81     IOMemoryDescriptor::withRanges;                          /* not supported */
  82     IOMemoryDescriptor::withSubRange;                        /* not supported */
  83
  84 public:
  85
  86 /*! @function withDescriptors
  87     @abstract Create an IOMultiMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
  88     @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.
  89     @param descriptors An array of IOMemoryDescriptors which make up the memory to be described.
  90     @param withCount The object count for the descriptors array.
  91     @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.
  92     @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.
  93     @result The created IOMultiMemoryDescriptor on success, to be released by the caller, or zero on failure. */
  94
  95     static IOMultiMemoryDescriptor * withDescriptors(
  96                                   IOMemoryDescriptor ** descriptors,
  97                                   UInt32                withCount,
  98                                   IODirection           withDirection,
  99                                   bool                  asReference = false );
 100
 101 /*! @function withDescriptors
 102     @abstract Initialize an IOMultiMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
 103     @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.
 104     @param descriptors An array of IOMemoryDescriptors which make up the memory to be described.
 105     @param withCount The object count for the descriptors array.
 106     @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.
 107     @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.
 108     @result The created IOMultiMemoryDescriptor on success, to be released by the caller, or zero on failure. */
 109
 110     virtual bool initWithDescriptors(
 111                                   IOMemoryDescriptor ** descriptors,
 112                                   UInt32                withCount,
 113                                   IODirection           withDirection,
 114                                   bool                  asReference = false );
 115
 116 /*! @function getPhysicalAddress
 117     @abstract Return the physical address of the first byte in the memory.
 118     @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.
 119     @result A physical address. */
 120
 121     virtual IOPhysicalAddress getPhysicalSegment( IOByteCount   offset,
 122                                                   IOByteCount * length );
 123
 124 /*! @function prepare
 125     @abstract Prepare the memory for an I/O transfer.
 126     @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.
 127     @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
 128     @result An IOReturn code. */
 129
 130     virtual IOReturn prepare(IODirection forDirection = kIODirectionNone);
 131
 132 /*! @function complete
 133     @abstract Complete processing of the memory after an I/O transfer finishes.
 134     @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.
 135     @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
 136     @result An IOReturn code. */
 137
 138     virtual IOReturn complete(IODirection forDirection = kIODirectionNone);
 139
 140 /*! @function readBytes
 141     @abstract Copy data from the memory descriptor's buffer to the specified buffer.
 142     @discussion This method copies data from the memory descriptor's memory at the given offset, to the caller's buffer.
 143     @param offset A byte offset into the memory descriptor's memory.
 144     @param bytes The caller supplied buffer to copy the data to.
 145     @param withLength The length of the data to copy.
 146     @result The number of bytes copied, zero will be returned if the specified offset is beyond the length of the descriptor. */
 147
 148     virtual IOByteCount readBytes( IOByteCount offset,
 149                                    void *      bytes,
 150                                    IOByteCount withLength );
 151
 152 /*! @function writeBytes
 153     @abstract Copy data to the memory descriptor's buffer from the specified buffer.
 154     @discussion This method copies data to the memory descriptor's memory at the given offset, from 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 from.
 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 writeBytes( IOByteCount  offset,
 161                                     const void * bytes,
 162                                     IOByteCount  withLength );
 163
 164     virtual IOPhysicalAddress getSourceSegment(IOByteCount offset,
 165                                                IOByteCount * length);
 166 };
 167
 168 #endif /* !_IOMULTIMEMORYDESCRIPTOR_H */