iokit/IOKit/IOMultiMemoryDescriptor.h

   1 /*
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  28
  29 #ifndef _IOMULTIMEMORYDESCRIPTOR_H
  30 #define _IOMULTIMEMORYDESCRIPTOR_H
  31
  32 #include <IOKit/IOMemoryDescriptor.h>
  33 #include <libkern/c++/OSPtr.h>
  34
  35 /*! @class IOMultiMemoryDescriptor : public IOMemoryDescriptor
  36  *   @abstract The IOMultiMemoryDescriptor object describes a memory area made up of several other IOMemoryDescriptors.
  37  *   @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. */
  38
  39 class IOMultiMemoryDescriptor : public IOMemoryDescriptor
  40 {
  41         OSDeclareDefaultStructors(IOMultiMemoryDescriptor);
  42
  43 protected:
  44
  45         IOMemoryDescriptor ** _descriptors;
  46         UInt32                _descriptorsCount;
  47         bool                  _descriptorsIsAllocated;
  48
  49         virtual void free() APPLE_KEXT_OVERRIDE;
  50
  51 public:
  52
  53 /*! @function withDescriptors
  54  *   @abstract Create an IOMultiMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
  55  *   @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.
  56  *   @param descriptors An array of IOMemoryDescriptors which make up the memory to be described.
  57  *   @param withCount The object count for the descriptors array.
  58  *   @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.
  59  *   @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.
  60  *   @result The created IOMultiMemoryDescriptor on success, to be released by the caller, or zero on failure. */
  61
  62         static OSPtr<IOMultiMemoryDescriptor>  withDescriptors(
  63                 IOMemoryDescriptor ** descriptors,
  64                 UInt32                withCount,
  65                 IODirection           withDirection,
  66                 bool                  asReference = false );
  67
  68 /*! @function withDescriptors
  69  *   @abstract Initialize an IOMultiMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
  70  *   @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.
  71  *   @param descriptors An array of IOMemoryDescriptors which make up the memory to be described.
  72  *   @param withCount The object count for the descriptors array.
  73  *   @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.
  74  *   @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.
  75  *   @result The created IOMultiMemoryDescriptor on success, to be released by the caller, or zero on failure. */
  76
  77         virtual bool initWithDescriptors(
  78                 IOMemoryDescriptor ** descriptors,
  79                 UInt32                withCount,
  80                 IODirection           withDirection,
  81                 bool                  asReference = false );
  82
  83 /*! @function getPhysicalSegment
  84  *   @abstract Break a memory descriptor into its physically contiguous segments.
  85  *   @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.
  86  *   @param offset A byte offset into the memory whose physical address to return.
  87  *   @param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset.
  88  *   @result A physical address, or zero if the offset is beyond the length of the memory. */
  89
  90         virtual addr64_t getPhysicalSegment( IOByteCount   offset,
  91             IOByteCount * length,
  92             IOOptionBits  options = 0 ) APPLE_KEXT_OVERRIDE;
  93
  94 /*! @function prepare
  95  *   @abstract Prepare the memory for an I/O transfer.
  96  *   @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.
  97  *   @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
  98  *   @result An IOReturn code. */
  99
 100         virtual IOReturn prepare(IODirection forDirection = kIODirectionNone) APPLE_KEXT_OVERRIDE;
 101
 102 /*! @function complete
 103  *   @abstract Complete processing of the memory after an I/O transfer finishes.
 104  *   @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.
 105  *   @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
 106  *   @result An IOReturn code. */
 107
 108         virtual IOReturn complete(IODirection forDirection = kIODirectionNone) APPLE_KEXT_OVERRIDE;
 109
 110         virtual IOReturn setPurgeable(IOOptionBits newState, IOOptionBits * oldState) APPLE_KEXT_OVERRIDE;
 111
 112         IOReturn setOwnership(task_t newOwner, int newLedgerTag, IOOptionBits newOptions);
 113
 114 /*! @function getPageCounts
 115  *   @abstract Retrieve the number of resident and/or dirty pages encompassed by an IOMemoryDescriptor.
 116  *   @discussion This method returns the number of resident and/or dirty pages encompassed by an IOMemoryDescriptor.
 117  *   @param residentPageCount - If non-null, a pointer to a byte count that will return the number of resident pages encompassed by this IOMemoryDescriptor.
 118  *   @param dirtyPageCount - If non-null, a pointer to a byte count that will return the number of dirty pages encompassed by this IOMemoryDescriptor.
 119  *   @result An IOReturn code. */
 120
 121         IOReturn getPageCounts(IOByteCount * residentPageCount,
 122             IOByteCount * dirtyPageCount);
 123
 124         virtual uint64_t getPreparationID( void ) APPLE_KEXT_OVERRIDE;
 125
 126 #define IOMULTIMEMORYDESCRIPTOR_SUPPORTS_GETPAGECOUNTS  1
 127
 128 private:
 129         virtual IOReturn doMap(vm_map_t           addressMap,
 130             IOVirtualAddress * atAddress,
 131             IOOptionBits       options,
 132             IOByteCount        sourceOffset = 0,
 133             IOByteCount        length = 0 ) APPLE_KEXT_OVERRIDE;
 134 };
 135
 136 #endif /* !_IOMULTIMEMORYDESCRIPTOR_H */