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CXGBE(4)                    Kernel Interfaces Manual                  CXGBE(4)

NAME
     cxgbe — Chelsio T4-, T5-, and T6-based 100Gb, 40Gb, 25Gb, 10Gb, and 1Gb
     Ethernet adapter driver

SYNOPSIS
     To compile this driver into the kernel, place the following lines in your
     kernel configuration file:

           device cxgbe

     To load the driver as a module at boot time, place the following lines in
     loader.conf(5):

           t4fw_cfg_load="YES"
           t5fw_cfg_load="YES"
           t6fw_cfg_load="YES"
           if_cxgbe_load="YES"

DESCRIPTION
     The cxgbe driver provides support for PCI Express Ethernet adapters based
     on the Chelsio Terminator 4, Terminator 5, and Terminator 6 ASICs (T4,
     T5, and T6).  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 http://www.chelsio.com/.

     The cxgbe driver uses different names for devices based on the associated
     ASIC:

           ASIC    Port Name    Parent Device    Virtual Interface
           T4      cxgbe        t4nex            vcxgbe
           T5      cxl          t5nex            vcxl
           T6      cc           t6nex            vcc

     Loader tunables with the hw.cxgbe prefix apply to all cards.  The driver
     provides sysctl MIBs for both ports and parent devices using the names
     above.  For example, a T5 adapter provides port MIBs under dev.cxl and
     adapter-wide MIBs under dev.t5nex.  References to sysctl MIBs in the
     remainder of this page use dev.<port> for port MIBs and dev.<nexus> for
     adapter-wide MIBs.

     For more information on configuring this device, see ifconfig(8).

HARDWARE
     The cxgbe driver supports 100Gb and 25Gb Ethernet adapters based on the
     T6 ASIC:

     ·   Chelsio T6225-CR
     ·   Chelsio T6225-SO-CR
     ·   Chelsio T62100-LP-CR
     ·   Chelsio T62100-SO-CR
     ·   Chelsio T62100-CR

     The cxgbe driver supports 40Gb, 10Gb and 1Gb Ethernet adapters based on
     the T5 ASIC:

     ·   Chelsio T580-CR
     ·   Chelsio T580-LP-CR
     ·   Chelsio T580-LP-SO-CR
     ·   Chelsio T560-CR
     ·   Chelsio T540-CR
     ·   Chelsio T540-LP-CR
     ·   Chelsio T522-CR
     ·   Chelsio T520-LL-CR
     ·   Chelsio T520-CR
     ·   Chelsio T520-SO
     ·   Chelsio T520-BT
     ·   Chelsio T504-BT

     The cxgbe driver supports 10Gb and 1Gb Ethernet adapters based on the T4
     ASIC:

     ·   Chelsio T420-CR
     ·   Chelsio T422-CR
     ·   Chelsio T440-CR
     ·   Chelsio T420-BCH
     ·   Chelsio T440-BCH
     ·   Chelsio T440-CH
     ·   Chelsio T420-SO
     ·   Chelsio T420-CX
     ·   Chelsio T420-BT
     ·   Chelsio T404-BT

LOADER TUNABLES
     Tunables can be set at the loader(8) prompt before booting the kernel or
     stored in loader.conf(5).  There are multiple tunables that control the
     number of queues of various types.  A negative value for such a tunable
     instructs the driver to create up to that many queues if there are enough
     CPU cores available.

     hw.cxgbe.ntxq
             Number of NIC tx queues used for a port.  The default is 16 or
             the number of CPU cores in the system, whichever is less.

     hw.cxgbe.nrxq
             Number of NIC rx queues used for a port.  The default is 8 or the
             number of CPU cores in the system, whichever is less.

     hw.cxgbe.nofldtxq
             Number of TOE tx queues used for a port.  The default is 8 or the
             number of CPU cores in the system, whichever is less.

     hw.cxgbe.nofldrxq
             Number of TOE rx queues used for a port.  The default is 2 or the
             number of CPU cores in the system, whichever is less.

     hw.cxgbe.num_vis
             Number of virtual interfaces (VIs) created for each port.  Each
             virtual interface creates a separate network interface.  The
             first virtual interface on each port is required and represents
             the primary network interface on the port.  Additional virtual
             interfaces on a port are named using the Virtual Interface name
             from the table above.  Additional virtual interfaces use a single
             pair of queues for rx and tx as well an additional pair of queues
             for TOE rx and tx.  The default is 1.

     hw.cxgbe.holdoff_timer_idx

     hw.cxgbe.holdoff_timer_idx_ofld
             Timer index value used 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.  holdoff_timer_idx_ofld applies to queues used for TOE
             rx.  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.<port>.X.holdoff_tmr_idx and
             dev.<port>.X.holdoff_tmr_idx_ofld sysctls.

     hw.cxgbe.holdoff_pktc_idx

     hw.cxgbe.holdoff_pktc_idx_ofld
             Packet-count index value used 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.  holdoff_pktc_idx_ofld
             applies to queues used for TOE rx.  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.<port>.X.holdoff_pktc_idx and
             dev.<port>.X.holdoff_pktc_idx_ofld sysctls.  These sysctls work
             only when the interface has never been marked up (as done by
             ifconfig up).

     hw.cxgbe.qsize_txq
             Number of entries in a transmit queue's descriptor ring.  A
             buf_ring of the same size is also allocated for additional
             software queuing.  See ifnet(9).  The default value is 1024.
             Different interfaces can be assigned different values via the
             dev.<port>.X.qsize_txq sysctl.  This sysctl works only when the
             interface has never been marked up (as done by ifconfig up).

     hw.cxgbe.qsize_rxq
             Number of entries in a receive queue's descriptor ring.  The
             default value is 1024.  Different interfaces can be assigned
             different values via the dev.<port>.X.qsize_rxq sysctl.  This
             sysctl works only when the interface has never been marked up (as
             done by ifconfig up).

     hw.cxgbe.interrupt_types
             Permitted interrupt types.  Bit 0 represents INTx (line
             interrupts), bit 1 MSI, and bit 2 MSI-X.  The default is 7 (all
             allowed).  The driver selects the best possible type out of the
             allowed types.

     hw.cxgbe.pcie_relaxed_ordering
             PCIe Relaxed Ordering.  -1 indicates the driver should determine
             whether to enable or disable PCIe RO.  0 disables PCIe RO.  1
             enables PCIe RO.  2 indicates the driver should not modify the
             PCIe RO setting.  The default is -1.

     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.

     hw.cxgbe.fl_pktshift
             Number of padding bytes inserted before the beginning of an
             Ethernet frame in the receive buffer.  The default value is 0.  A
             value of of 2 would ensure that the Ethernet payload (usually the
             IP header) is at a 4 byte aligned address.  0-7 are all valid
             values.

     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.

     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.

     hw.cxgbe.pause_settings
             PAUSE frame settings.  Bit 0 is rx_pause, bit 1 is tx_pause, bit
             2 is pause_autoneg.  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.  pause_autoneg = 1 overrides the rx_pause and
             tx_pause bits and instructs the hardware to negotiate PAUSE
             settings with the link peer.  The default is 7 (all three = 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.<port>.X.pause_settings sysctl.

     hw.cxgbe.fec
             FEC (Forward Error Correction) settings.  0 diables FEC.  Bit 0
             enables RS FEC, bit 1 enables BASE-R FEC (aka Firecode FEC).  The
             default is -1 which lets the driver pick a value.  This tunable
             establishes the default FEC settings for all ports.  Settings can
             be displayed and controlled on a per-port basis via the
             dev.<port>.X.fec sysctl.

     hw.cxgbe.autoneg
             Link autonegotiation settings.  This tunable establishes the
             default autonegotiation settings for all ports.  Settings can be
             displayed and controlled on a per-port basis via the
             dev.<port>.X.autoneg sysctl.  0 disables autonegotiation.  1
             enables autonegotiation.  The default is -1 which lets the driver
             pick a value.  dev.<port>.X.autoneg is -1 for port and module
             combinations that do not support autonegotiation.

     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.

     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.

     hw.cxgbe.largest_rx_cluster

     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 never attempts to allocate a receive buffer larger
             than largest_rx_cluster and falls 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.

     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.<nexus>.X.cf and dev.<nexus>.X.cfcsum sysctls.

     hw.cxgbe.linkcaps_allowed

     hw.cxgbe.niccaps_allowed

     hw.cxgbe.toecaps_allowed

     hw.cxgbe.rdmacaps_allowed

     hw.cxgbe.iscsicaps_allowed

     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.<nexus>.X.*caps sysctls.

SUPPORT
     For general information and support, go to the Chelsio support website
     at: http://www.chelsio.com/.

     If an issue is identified with this driver with a supported adapter,
     email all the specific information related to the issue to
     ⟨support@chelsio.com⟩.

SEE ALSO
     altq(4), arp(4), ccr(4), cxgb(4), cxgbev(4), netintro(4), ng_ether(4),
     ifconfig(8)

HISTORY
     The cxgbe device driver first appeared in FreeBSD 9.0.  Support for T5
     cards first appeared in FreeBSD 9.2 and FreeBSD 10.0.  Support for T6
     cards first appeared in FreeBSD 11.1 and FreeBSD 12.0.

AUTHORS
     The cxgbe driver was written by Navdeep Parhar <np@FreeBSD.org>.

                                 Sep 24, 2018