xref: /freebsd/share/man/man4/sume.4 (revision 2e3f49888ec8851bafb22011533217487764fdb0)
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27.Dd August 30, 2020
28.Dt SUME 4
29.Os
30.Sh NAME
31.Nm sume
32.Nd "NetFPGA SUME 4x10Gb Ethernet driver"
33.Sh SYNOPSIS
34To compile this driver into the kernel, place the following lines
35in your kernel configuration file:
36.Bd -ragged -offset indent
37.Cd "device sume"
38.Ed
39.Pp
40Alternatively, to load the driver as a module at boot time, place
41the following line in
42.Xr loader.conf 5 :
43.Bd -literal -offset indent
44if_sume_load="YES"
45.Ed
46.Sh DESCRIPTION
47The
48.Nm
49driver provides support for NetFPGA SUME Virtex-7 FPGA Development Board
50with the reference NIC bitstream loaded onto it.
51The HDL design for the reference NIC project uses the RIFFA based DMA
52engine to communicate with the host machine over PCIe.
53Every packet is transmitted to / from the board via a single DMA
54transaction, taking up to two or three interrupts per one transaction
55which yields low performance.
56.Pp
57There is no support for Jumbo frames as the hardware is capable of
58dealing only with frames with maximum size of 1514 bytes.
59The hardware does not support multicast filtering, provides no checksums,
60and offers no other offloading.
61.Sh SEE ALSO
62.Xr arp 4 ,
63.Xr netgraph 4 ,
64.Xr netintro 4 ,
65.Xr ng_ether 4 ,
66.Xr vlan 4 ,
67.Xr ifconfig 8
68.Sh AUTHORS
69The Linux
70.Nm
71driver was originally written by
72.An -nosplit
73.An Bjoern A. Zeeb .
74The
75.Fx version and this manual page were written by
76.An Denis Salopek
77as a GSoC project.
78More information about the project can be found here:
79.Pa https://wiki.freebsd.org/SummerOfCode2020Projects/NetFPGA_SUME_Driver
80.Sh BUGS
81The reference NIC hardware design provides no mechanism for quiescing
82inbound traffic from interfaces configured as DOWN.
83All packets from administratively disabled interfaces are transferred to
84main memory, leaving the driver with the task of dropping such packets,
85thus consuming PCI bandwidth, interrupts and CPU cycles in vain.
86.Pp
87Pre-built FPGA bitstream from the NetFPGA project may not work correctly.
88At higher RX packet rates, the newly incoming packets can overwrite the
89ones in an internal FIFO so the packets would arrive in main memory
90corrupted, until a physical reset of the board.
91.Pp
92Occasionally, the driver can get stuck in a non-IDLE TX state due to
93a missed interrupt.
94The driver includes a watchdog function which monitors for such a
95condition and resets the board automatically.
96For more details, visit the NetFPGA SUME project site.
97