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.\" $FreeBSD$
.\"
.Dd March 20, 2014
.Dt CXGBE 4
.Os
.Sh NAME
.Nm cxgbe
.Nd "Chelsio T4 and T5 based 40Gb, 10Gb, and 1Gb Ethernet adapter 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 cxgbe"
.Ed
.Pp
To load the driver as a
module at boot time, place the following lines in
.Xr loader.conf 5 :
.Bd -literal -offset indent
t4fw_cfg_load="YES"
t5fw_cfg_load="YES"
if_cxgbe_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
driver provides support for PCI Express Ethernet adapters based on
the Chelsio Terminator 4 and Terminator 5 ASICs (T4 and T5).
The driver supports Jumbo Frames, Transmit/Receive checksum offload,
TCP segmentation offload (TSO), Large Receive Offload (LRO), VLAN
tag insertion/extraction, VLAN checksum offload, VLAN TSO, and
Receive Side Steering (RSS).
For further hardware information and questions related to hardware
requirements, see
.Pa http://www.chelsio.com/ .
.Pp
Note that ports of T5 cards are named cxl and attach to a t5nex parent device
(in contrast to ports named cxgbe that attach to a t4nex parent for a T4 card).
Loader tunables with the hw.cxgbe prefix apply to both T4 and T5 cards.
The sysctl MIBs are at dev.t5nex and dev.cxl for T5 cards and at dev.t4nex and
dev.cxgbe for T4 cards.

.Pp
For more information on configuring this device, see
.Xr ifconfig 8 .
.Sh HARDWARE
The
.Nm
driver supports 40Gb, 10Gb and 1Gb Ethernet adapters based on the T5 ASIC
(ports will be named cxl):
.Pp
.Bl -bullet -compact
.It
Chelsio T580-CR
.It
Chelsio T580-LP-CR
.It
Chelsio T580-LP-SO-CR
.It
Chelsio T560-CR
.It
Chelsio T540-CR
.It
Chelsio T540-LP-CR
.It
Chelsio T522-CR
.It
Chelsio T520-LL-CR
.It
Chelsio T520-CR
.It
Chelsio T520-SO
.It
Chelsio T520-BT
.It
Chelsio T504-BT
.El
.Pp
The
.Nm
driver supports 10Gb and 1Gb Ethernet adapters based on the T4 ASIC:
.Pp
.Bl -bullet -compact
.It
Chelsio T420-CR
.It
Chelsio T422-CR
.It
Chelsio T440-CR
.It
Chelsio T420-BCH
.It
Chelsio T440-BCH
.It
Chelsio T440-CH
.It
Chelsio T420-SO
.It
Chelsio T420-CX
.It
Chelsio T420-BT
.It
Chelsio T404-BT
.El
.Sh LOADER TUNABLES
Tunables can be set at the
.Xr loader 8
prompt before booting the kernel or stored in
.Xr loader.conf 5 .
.Bl -tag -width indent
.It Va hw.cxgbe.ntxq10g
The number of tx queues to use for a 10Gb or 40Gb port.
The default is 16 or the number
of CPU cores in the system, whichever is less.
.It Va hw.cxgbe.nrxq10g
The number of rx queues to use for a 10Gb or 40Gb port.
The default is 8 or the number
of CPU cores in the system, whichever is less.
.It Va hw.cxgbe.ntxq1g
The number of tx queues to use for a 1Gb port.
The default is 4 or the number
of CPU cores in the system, whichever is less.
.It Va hw.cxgbe.nrxq1g
The number of rx queues to use for a 1Gb port.
The default is 2 or the number
of CPU cores in the system, whichever is less.
.It Va hw.cxgbe.nofldtxq10g
The number of TOE tx queues to use for a 10Gb or 40Gb port.
The default is 8 or the
number of CPU cores in the system, whichever is less.
.It Va hw.cxgbe.nofldrxq10g
The number of TOE rx queues to use for a 10Gb or 40Gb port.
The default is 2 or the
number of CPU cores in the system, whichever is less.
.It Va hw.cxgbe.nofldtxq1g
The number of TOE tx queues to use for a 1Gb port.
The default is 2 or the
number of CPU cores in the system, whichever is less.
.It Va hw.cxgbe.nofldrxq1g
The number of TOE rx queues to use for a 1Gb port.
The default is 1.
.It Va hw.cxgbe.holdoff_timer_idx_10G
.It Va hw.cxgbe.holdoff_timer_idx_1G
The timer index value to use to delay interrupts.
The holdoff timer list has the values 1, 5, 10, 50, 100, and 200
by default (all values are in microseconds) and the index selects a
value from this list.
The default value is 1 which means the timer value is 5us.
Different interfaces can be assigned different values at any time via the
dev.cxgbe.X.holdoff_tmr_idx or dev.cxl.X.holdoff_tmr_idx sysctl.
.It Va hw.cxgbe.holdoff_pktc_idx_10G
.It Va hw.cxgbe.holdoff_pktc_idx_1G
The packet-count index value to use to delay interrupts.
The packet-count list has the values 1, 8, 16, and 32 by default
and the index selects a value from this list.
The default value is -1 which means packet counting is disabled and interrupts
are generated based solely on the holdoff timer value.
Different interfaces can be assigned different values via the
dev.cxgbe.X.holdoff_pktc_idx or dev.cxl.X.holdoff_pktc_idx sysctl.
This sysctl works only when the interface has never been marked up (as done by
ifconfig up).
.It Va hw.cxgbe.qsize_txq
The size, in number of entries, of the descriptor ring used for a tx
queue.
A buf_ring of the same size is also allocated for additional
software queuing.
See
.Xr ifnet 9 .
The default value is 1024.
Different interfaces can be assigned different values via the
dev.cxgbe.X.qsize_txq sysctl or dev.cxl.X.qsize_txq sysctl.
This sysctl works only when the interface has never been marked up (as done by
ifconfig up).
.It Va hw.cxgbe.qsize_rxq
The size, in number of entries, of the descriptor ring used for an
rx queue.
The default value is 1024.
Different interfaces can be assigned different values via the
dev.cxgbe.X.qsize_rxq or dev.cxl.X.qsize_rxq sysctl.
This sysctl works only when the interface has never been marked up (as done by
ifconfig up).
.It Va hw.cxgbe.interrupt_types
The interrupt types that the driver is allowed to use.
Bit 0 represents INTx (line interrupts), bit 1 MSI, bit 2 MSI-X.
The default is 7 (all allowed).
The driver will select the best possible type out of the allowed types by
itself.
.It Va hw.cxgbe.fw_install
0 prohibits the driver from installing a firmware on the card.
1 allows the driver to install a new firmware if internal driver
heuristics indicate that the new firmware is preferable to the one
already on the card.
2 instructs the driver to always install the new firmware on the card as
long as it is compatible with the driver and is a different version than
the one already on the card.
The default is 1.
.It Va hw.cxgbe.fl_pktshift
The number of bytes of padding inserted before the begining of an Ethernet
frame in the receive buffer.
The default value of 2 ensures that the Ethernet payload (usually the IP header)
is at a 4 byte aligned address.
0-7 are all valid values.
.It Va hw.cxgbe.fl_pad
A non-zero value ensures that writes from the hardware to a receive buffer are
padded up to the specified boundary.
The default is -1 which lets the driver pick a pad boundary.
0 disables trailer padding completely.
.It Va hw.cxgbe.cong_drop
Controls the hardware response to congestion.
-1 disables congestion feedback and is not recommended.
0 instructs the hardware to backpressure its pipeline on congestion.
This usually results in the port emitting PAUSE frames.
1 instructs the hardware to drop frames destined for congested queues.
.It Va hw.cxgbe.pause_settings
PAUSE frame settings.
Bit 0 is rx_pause, bit 1 is tx_pause.
rx_pause = 1 instructs the hardware to heed incoming PAUSE frames, 0 instructs
it to ignore them.
tx_pause = 1 allows the hardware to emit PAUSE frames when its receive FIFO
reaches a high threshold, 0 prohibits the hardware from emitting PAUSE frames.
The default is 3 (both rx_pause and tx_pause = 1).
This tunable establishes the default PAUSE settings for all ports.
Settings can be displayed and controlled on a per-port basis via the
dev.cxgbe.X.pause_settings (dev.cxl.X.pause_settings for T5 cards) sysctl.
.It Va hw.cxgbe.buffer_packing
Allow the hardware to deliver multiple frames in the same receive buffer
opportunistically.
The default is -1 which lets the driver decide.
0 or 1 explicitly disable or enable this feature.
.It Va hw.cxgbe.allow_mbufs_in_cluster
1 allows the driver to lay down one or more mbufs within the receive buffer
opportunistically.  This is the default.
0 prohibits the driver from doing so.
.It Va hw.cxgbe.largest_rx_cluster
.It Va hw.cxgbe.safest_rx_cluster
Sizes of rx clusters.  Each of these must be set to one of the sizes available
(usually 2048, 4096, 9216, and 16384) and largest_rx_cluster must be greater
than or equal to safest_rx_cluster.
The defaults are 16384 and 4096 respectively.
The driver will never attempt to allocate a receive buffer larger than
largest_rx_cluster and will fall back to allocating buffers of
safest_rx_cluster size if an allocation larger than safest_rx_cluster fails.
Note that largest_rx_cluster merely establishes a ceiling -- the driver is
allowed to allocate buffers of smaller sizes.
.It Va hw.cxgbe.config_file
Select a pre-packaged device configuration file.
A configuration file contains a recipe for partitioning and configuring the
hardware resources on the card.
This tunable is for specialized applications only and should not be used in
normal operation.
The configuration profile currently in use is available in the dev.t4nex.X.cf
and dev.t4nex.X.cfcsum (dev.t5nex for T5 cards) sysctls.
.It Va hw.cxgbe.linkcaps_allowed
.It Va hw.cxgbe.niccaps_allowed
.It Va hw.cxgbe.toecaps_allowed
.It Va hw.cxgbe.rdmacaps_allowed
.It Va hw.cxgbe.iscsicaps_allowed
.It Va hw.cxgbe.fcoecaps_allowed
Disallowing capabilities provides a hint to the driver and firmware to not
reserve hardware resources for that feature.
Each of these is a bit field with a bit for each sub-capability within the
capability.
This tunable is for specialized applications only and should not be used in
normal operation.
The capabilities for which hardware resources have been reserved are listed in
dev.t4nex.X.*caps or dev.t5nex.X.*caps sysctls.
.El
.Sh SUPPORT
For general information and support,
go to the Chelsio support website at:
.Pa http://www.chelsio.com/ .
.Pp
If an issue is identified with this driver with a supported adapter,
email all the specific information related to the issue to
.Aq support@chelsio.com .
.Sh SEE ALSO
.Xr altq 4 ,
.Xr arp 4 ,
.Xr cxgb 4 ,
.Xr netintro 4 ,
.Xr ng_ether 4 ,
.Xr ifconfig 8
.Sh HISTORY
The
.Nm
device driver first appeared in
.Fx 9.0 .
Support for T5 cards first appeared in
.Fx 9.2
and
.Fx 10.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Navdeep Parhar Aq np@FreeBSD.org .