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#ifndef _IOINTERLEAVEDMEMORYDESCRIPTOR_H
#define _IOINTERLEAVEDMEMORYDESCRIPTOR_H
#include <IOKit/IOMemoryDescriptor.h>
#include <libkern/c++/OSPtr.h>
/*! @class IOInterleavedMemoryDescriptor : public IOMemoryDescriptor
* @abstract The IOInterleavedMemoryDescriptor object describes a memory area made up of portions of several other IOMemoryDescriptors.
* @discussion The IOInterleavedMemoryDescriptor object represents interleaved ranges of memory, specified as an ordered list of portions of individual IOMemoryDescriptors. The portions are chained end-to-end to make up a single contiguous buffer. */
class IOInterleavedMemoryDescriptor : public IOMemoryDescriptor
{
OSDeclareDefaultStructors(IOInterleavedMemoryDescriptor);
protected:
IOByteCount _descriptorCapacity;
UInt32 _descriptorCount;
IOMemoryDescriptor ** _descriptors;
IOByteCount * _descriptorOffsets;
IOByteCount * _descriptorLengths;
bool _descriptorPrepared;
virtual void free() APPLE_KEXT_OVERRIDE;
public:
/*! @function withCapacity
* @abstract Create an IOInterleavedMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
* @discussion This method creates and initializes an IOInterleavedMemoryDescriptor for memory consisting of portions 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.
* @param capacity The maximum number of IOMemoryDescriptors that may be subsequently added to this IOInterleavedMemoryDescriptor.
* @param direction An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
* @result The created IOInterleavedMemoryDescriptor on success, to be released by the caller, or zero on failure. */
static OSPtr<IOInterleavedMemoryDescriptor> withCapacity( IOByteCount capacity,
IODirection direction);
/*! @function initWithCapacity
* @abstract Initialize an IOInterleavedMemoryDescriptor to describe a memory area made up of several other IOMemoryDescriptors.
* @discussion This method initializes an IOInterleavedMemoryDescriptor for memory consisting of portions 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.
* @param capacity The maximum number of IOMemoryDescriptors that may be subsequently added to this IOInterleavedMemoryDescriptor.
* @param direction An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures.
* @result The created IOInterleavedMemoryDescriptor on success, to be released by the caller, or zero on failure. */
virtual bool initWithCapacity( IOByteCount capacity,
IODirection direction );
/*! @function clearMemoryDescriptors
* @abstract Clear all of the IOMemoryDescriptors currently contained in and reset the IOInterleavedMemoryDescriptor.
* @discussion Clears each IOMemoryDescriptor by completing (if needed) and releasing. The IOInterleavedMemoryDescriptor is then reset and may accept new descriptors up to the capacity specified when it was created.
* @param direction An I/O direction to be associated with the descriptor, which may affect the operation of the prepare and complete methods on some architectures. */
virtual void clearMemoryDescriptors( IODirection direction = kIODirectionNone );
/*! @function setMemoryDescriptor
* @abstract Add a portion of an IOMemoryDescriptor to the IOInterleavedMemoryDescriptor.
* @discussion This method adds the portion of an IOMemoryDescriptor described by the offset and length parameters to the end of the IOInterleavedMemoryDescriptor. A single IOMemoryDescriptor may be added as many times as there is room for it. The offset and length must describe a portion entirely within the IOMemoryDescriptor.
* @param descriptor An IOMemoryDescriptor to be added to the IOInterleavedMemoryDescriptor. Its direction must be compatible with that of the IOInterleavedMemoryDescriptor.
* @param offset The offset into the IOMemoryDescriptor of the portion that will be added to the virtualized buffer.
* @param length The length of the portion of the IOMemoryDescriptor to be added to the virtualized buffer.
* @result Returns true the portion was successfully added. */
virtual bool setMemoryDescriptor( IOMemoryDescriptor * descriptor,
IOByteCount offset,
IOByteCount length );
/*! @function getPhysicalSegment
* @abstract Break a memory descriptor into its physically contiguous segments.
* @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.
* @param offset A byte offset into the memory whose physical address to return.
* @param length If non-zero, getPhysicalSegment will store here the length of the physically contiguous segement at the given offset.
* @result A physical address, or zero if the offset is beyond the length of the memory. */
virtual addr64_t getPhysicalSegment( IOByteCount offset,
IOByteCount * length,
IOOptionBits options = 0 ) APPLE_KEXT_OVERRIDE;
/*! @function prepare
* @abstract Prepare the memory for an I/O transfer.
* @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 need not called for non-pageable memory.
* @param forDirection The direction of the I/O to be performed, or kIODirectionNone for the direction specified by the memory descriptor.
* @result An IOReturn code. */
virtual IOReturn prepare(IODirection forDirection = kIODirectionNone) APPLE_KEXT_OVERRIDE;
/*! @function complete
* @abstract Complete processing of the memory after an I/O transfer finishes.
* @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.
* @param forDirection The direction of the I/O just completed, or kIODirectionNone for the direction specified by the memory descriptor.
* @result An IOReturn code. */
virtual IOReturn complete(IODirection forDirection = kIODirectionNone) APPLE_KEXT_OVERRIDE;
};
#endif /* !_IOINTERLEAVEDMEMORYDESCRIPTOR_H */