iokit/IOKit/IODMACommand.h

187     @param maxTransferSize Maximum size of an entire transfer.	Defaults to 0 indicating no maximum.
210     @param maxTransferSize Maximum size of an entire transfer.  Defaults to 0 indicating no maximum.
245     @param maxTransferSize Maximum size of an entire transfer.	Defaults to 0 indicating no maximum.
282     @abstract Prepare the memory for an I/O transfer.
283     @discussion Allocate the mapping resources neccessary for this transfer, specifying a sub range of the IOMemoryDescriptor that will be the target of the I/O.  The complete() method frees these resources.  Data may be copied to buffers for kIODirectionOut memory descriptors, depending on hardware mapping resource availabilty or alignment restrictions.  It should be noted that the this function may block and should only be called on the clients context, i.e never call this routine while gated; also the call itself is not thread safe though this should be an issue as each IODMACommand is independant.
293     @abstract Complete processing of DMA mappings after an I/O transfer is finished.
294     @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
325     virtual UInt64 transfer( IOOptionBits transferOp, UInt64 offset, void * buffer, UInt64 length );
403     @abstract Prepare the memory for an I/O transfer with a new specification.
404     @discussion Allocate the mapping resources neccessary for this transfer, specifying a sub range of the IOMemoryDescriptor that will be the target of the I/O.  The complete() method frees these resources.  Data may be copied to buffers for kIODirectionOut memory descriptors, depending on hardware mapping resource availabilty or alignment restrictions.  It should be noted that the this function may block and should only be called on the clients context, i.e never call this routine while gated; also the call itself is not thread safe though this should be an issue as each IODMACommand is independant.
409     @param maxTransferSize Maximum size of an entire transfer.	Defaults to 0 indicating no maximum.
478     Maximum size of a transfer that this memory cursor is allowed to generate */