Xilinx KCU105 User Manual page 62

from which the transfer took place. Optional callbacks are invoked for both SGL
descriptors so that application drivers can do the necessary post-data transfer clean up.
Performing Transfers using the XDMA Driver with Windows
The following are required for an application driver to make use of an XDMA driver to
perform data transfer between the host and EP in a Windows environment.
Application Driver Registration
The application driver must register itself with the XDMA driver to be able to communicate
through the DMA channel of its choice. The DMA driver exports an interface for other
drivers to enable this registration process.
The application driver has to open an interface exported by the XDMA driver and invoke
DmaRegister and relevant information such as number of buffer descriptors, coalesce
count, and callback routines to be invoked after transfers are complete.
If the channel requested by the aplication driver is free, the DMA driver accepts the
registration of the application driver and provides a handle to it for initiating transfers.
Initiating Transfers
The application driver can initiate transfers using the handle provided by the XDMA driver
after registration. Using the XDMADataTransfer API, an application driver can update either
the source or destination SGL of the channel by specifying the relevant value in
QueueToBeServiced parameter.
Callback Invocation
After completion of the DMA transaction, either transmit or receive for a particular channel.
the relevant callback provided by the application driver during the registration phase is
invoked. The application driver can take appropriate action based on the information
provided by the DMA driver, such as number of bytes completed or notification of errors (if
any) during the transfer.
PCIe Streaming Data Plane TRD
UG920 (v2017.1) June 01, 2017
Chapter 5: Targeted Reference Design Details and Modifications
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