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.\"-
.\" SPDX-License-Identifier: BSD-2-Clause-FreeBSD
.\"
.\" Copyright (c) 2020 Denis Salopek
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
.\" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd August 30, 2020
.Dt SUME 4
.Os
.Sh NAME
.Nm sume
.Nd "NetFPGA SUME 4x10Gb Ethernet driver"
.Sh SYNOPSIS
To compile this driver into the kernel, place the following lines
in your kernel configuration file:
.Bd -ragged -offset indent
.Cd "device sume"
.Ed
.Pp
Alternatively, to load the driver as a module at boot time, place
the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
if_sume_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
driver provides support for NetFPGA SUME Virtex-7 FPGA Development Board
with the reference NIC bitstream loaded onto it.
The HDL design for the reference NIC project uses the RIFFA based DMA
engine to communicate with the host machine over PCIe.
Every packet is transmitted to / from the board via a single DMA
transaction, taking up to two or three interrupts per one transaction
which yields low performance.
.Pp
There is no support for Jumbo frames as the hardware is capable of
dealing only with frames with maximum size of 1514 bytes.
The hardware does not support multicast filtering, provides no checksums,
and offers no other offloading.
.Sh SEE ALSO
.Xr arp 4 ,
.Xr netgraph 4 ,
.Xr netintro 4 ,
.Xr ng_ether 4 ,
.Xr vlan 4 ,
.Xr ifconfig 8
.Sh AUTHORS
The Linux
.Nm
driver was originally written by
.An -nosplit
.An Bjoern A. Zeeb .
The
.Fx version and this manual page were written by
.An Denis Salopek
as a GSoC project.
More information about the project can be found here:
.Pa https://wiki.freebsd.org/SummerOfCode2020Projects/NetFPGA_SUME_Driver
.Sh BUGS
The reference NIC hardware design provides no mechanism for quiescing
inbound traffic from interfaces configured as DOWN.
All packets from administratively disabled interfaces are transferred to
main memory, leaving the driver with the task of dropping such packets,
thus consuming PCI bandwidth, interrupts and CPU cycles in vain.
.Pp
Pre-built FPGA bitstream from the NetFPGA project may not work correctly.
At higher RX packet rates, the newly incoming packets can overwrite the
ones in an internal FIFO so the packets would arrive in main memory
corrupted, until a physical reset of the board.
.Pp
Occasionally, the driver can get stuck in a non-IDLE TX state due to
a missed interrupt.
The driver includes a watchdog function which monitors for such a
condition and resets the board automatically.
For more details, visit the NetFPGA SUME project site.