1.\" Copyright (c) 2008 Pyun YongHyeon 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD: src/share/man/man4/jme.4,v 1.1 2008/05/27 01:59:17 yongari Exp $ 26.\" 27.Dd May 29, 2017 28.Dt JME 4 29.Os 30.Sh NAME 31.Nm jme 32.Nd JMicron Gigabit/Fast Ethernet driver 33.Sh SYNOPSIS 34To compile this driver into the kernel, 35place the following lines in your 36kernel configuration file: 37.Bd -ragged -offset indent 38.Cd "device miibus" 39.Cd "device jme" 40.Ed 41.Pp 42Alternatively, to load the driver as a 43module at boot time, place the following line in 44.Xr loader.conf 5 : 45.Bd -literal -offset indent 46if_jme_load="YES" 47.Ed 48.Sh DESCRIPTION 49The 50.Nm 51device driver provides support for JMicron JMC250 PCI Express 52Gigabit Ethernet controllers and JMicron JMC260 PCI Express Fast 53Ethernet controllers. 54.Pp 55All LOMs supported by the 56.Nm 57driver have TCP/UDP/IP checksum offload for both transmit and receive, 58TCP segmentation offload (TSO), 59receive side scaling (RSS), 60multiple vector MSI-X, 61hardware VLAN tag stripping/insertion features, 62.\" Wake On Lan (WOL) 63an interrupt coalescing/moderation mechanism as well as 64a 64-bit multicast hash filter. 65Up to 4 reception queues can be enabled. 66By default, the 67.Nm 68driver will try enabling as many reception queues as allowed by 69the number of CPUs in the system. 70.Pp 71The JMC250 also supports Jumbo Frames (up to 9216 bytes), which can be 72configured via the interface MTU setting. 73Selecting an MTU larger than 1500 bytes with the 74.Xr ifconfig 8 75utility configures the adapter to receive and transmit Jumbo Frames. 76.Pp 77The 78.Nm 79driver supports the following media types: 80.Bl -tag -width ".Cm 10baseT/UTP" 81.It Cm autoselect 82Enable autoselection of the media type and options. 83The user can manually override 84the autoselected mode by adding media options to 85.Xr rc.conf 5 . 86.It Cm 10baseT/UTP 87Set 10Mbps operation. 88.It Cm 100baseTX 89Set 100Mbps (Fast Ethernet) operation. 90.It Cm 1000baseT 91Set 1000baseT operation over twisted pair. 92.El 93.Pp 94The 95.Nm 96driver supports the following media options: 97.Bl -tag -width ".Cm full-duplex" 98.It Cm full-duplex 99Force full duplex operation. 100.It Cm half-duplex 101Force half duplex operation. 102.El 103.Pp 104For more information on configuring this device, see 105.Xr ifconfig 8 . 106The 107.Nm 108driver supports 109.Xr polling 4 . 110.Ss Loader Tunables 111By default, the driver will use MSI-X if it is supported. 112This behavior can be turned off by setting the following tunable: 113.Em ( X 114is the device unit number): 115.Bd -literal -offset indent 116hw.jme.msix.enable=0 117hw.jmeX.msix.enable=0 118.Ed 119.Pp 120If MSI-X is disabled, 121the driver will use MSI if it is supported. 122This behavior can be turned off by setting the following tunable: 123.Bd -literal -offset indent 124hw.jme.msi.enable=0 125hw.jmeX.msi.enable=0 126.Ed 127.Pp 128If MSI is used, 129MSI's target CPU can be changed by the following tunable: 130.Bd -literal -offset indent 131hw.jmeX.msi.cpu 132.Ed 133.Pp 134The maximum allowed value for this tunable is the number of CPUs minus one. 135.Pp 136Number of reception queues that can be enabled: 137.Bd -literal -offset indent 138hw.jme.rx_ring_count 139hw.jmeX.rx_ring_count 140.Ed 141.Pp 142Maximum allowed value for these tunables is 4. 143Setting these tunables to 0 allows driver to enable as many reception queues 144as allowed by the number of CPUs. 145.Pp 146Number of reception descriptors that can be used: 147.Bd -literal -offset indent 148hw.jme.rx_desc_count 149hw.jmeX.rx_desc_count 150.Ed 151.Pp 152Maximum allowed value for these tunables is 1024. 153.Pp 154Number of transmission descriptors that can be used: 155.Bd -literal -offset indent 156hw.jme.tx_desc_count 157hw.jmeX.tx_desc_count 158.Ed 159.Pp 160Maximum allowed value for these tunables is 1024. 161.Ss MIB Variables 162A number of per-interface variables are implemented in the 163.Va dev.jme. Ns Em X 164branch of the 165.Xr sysctl 3 166MIB. 167.Bl -tag -width "rx_ring_count" 168.It Va tx_coal_to 169Maximum amount of time to delay for TX completion interrupt in 170units of 1us. 171The accepted range is 1 to 65535, the default is 250 (250us). 172.It Va tx_coal_pkt 173Maximum number of packets to fire TX completion interrupt. 174The accepted range is 0 to 255, the default is 128. 175Packet count based TX interrupt coalescing could be disabled 176by setting this variable to 0. 177.It Va rx_coal_to 178Maximum amount of time to delay for RX completion interrupt in 179units of 1us. 180The accepted range is 1 to 65535, the default is 150 (150us). 181.It Va rx_coal_pkt 182Maximum number of packets to fire RX completion interrupt. 183The accepted range is 0 to 255, the default is 64. 184Packet count based RX interrupt coalescing could be disabled 185by setting this variable to 0. 186.It Va rx_desc_count 187Number of RX descriptors per-ring (read-only). 188Use the tunable 189.Va hw.jme.rx_desc_count 190to configure it. 191.It Va tx_desc_count 192Number of TX descriptors (read-only). 193Use the tunable 194.Va hw.jme.tx_desc_count 195to configure it. 196.It Va rx_ring_count 197Number of RX rings (read-only). 198Use the tunable 199.Va hw.jme.rx_ring_count 200to configure it. 201.It Va tx_wreg 202The number of transmission descriptors should be setup 203before the hardware register is written. 204Setting this value too high will have negative effect on 205transmission timeliness. 206Setting this value too low will hurt overall transmission 207due to the frequent hardware register writing. 208.El 209.Sh SEE ALSO 210.Xr altq 4 , 211.Xr arp 4 , 212.Xr ifmedia 4 , 213.Xr miibus 4 , 214.Xr netintro 4 , 215.Xr ng_ether 4 , 216.Xr polling 4 , 217.Xr vlan 4 , 218.Xr ifconfig 8 219.Sh HISTORY 220The 221.Nm 222driver was written by 223.An Pyun YongHyeon Aq Mt yongari@FreeBSD.org . 224It first appeared in 225.Fx 7.1 226and was imported into 227.Dx 2.1 . 228.An Sepherosa Ziehau 229added the receive side scaling and 230multiple vector MSI-X support to 231.Dx . 232