Xilinx KCU105 User Manual page 87

Card to system:
1. The DMA driver receives the packet from buffer descriptor and submits the packets with
registered callback functions to the Ethernet driver.
2. The Ethernet driver submits the received packets to the networking stack. which is in
turn submitted to the appropriate application.
Control Path
Networking tools:
The Ethernet functionality in the driver does not require the Control & Monitoring GUI to be
operational. Ethernet comes up with the previously configured settings. Standard Linux
networking tools (for example, ifconfig and ethtool) can be used by the system
administrator when the configuration needs to be changed. The driver provides the
necessary hooks that enable standard tools to communicate with it.
GUI:
The GUI does not control test parameters and traffic generation. The GUI only displays
power. Periodically the GUI polls and updates the statistics through the DMA driver entry
points. The performance monitor is a handler that reads all performance-related registers
(link level for PCI Express, DMA engine level, and power level). Each of these is read
periodically at an interval of one second.
Software for Raw Ethernet Application:
This mode works similarly to the Base Raw data design. The application driver is the
character driver and the User application sends raw data with Ethernet headers appended in
the first 12 bytes. Because there is no Ethernet stack involved in data transfer, networking
stack overhead is eliminated. The two network interfaces are connected back-to-back. The
destination address in the Ethernet header is programmed as a broadcast message. A
packet is transmitted from one network interface and received as a broadcast packet on the
other interface.
This demonstrates maximum performance in eliminating networking stack overhead.
PCIe Streaming Data Plane TRD
UG920 (v2017.1) June 01, 2017
Chapter 5: Targeted Reference Design Details and Modifications
www.xilinx.com 87
Send Feedback