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BXE(4)		       FreeBSD Kernel Interfaces Manual			BXE(4)

     bxe -- Broadcom NetXtreme II Ethernet 10Gb	PCIe adapter driver

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

	   device bxe

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


     The bxe driver provides support for PCIe 10Gb Ethernet adapters based on
     the Broadcom NetXtreme II family of 10Gb chips.  The driver supports
     Jumbo Frames, VLAN	tagging, checksum offload (IPv4, TCP, UDP, IPv6-TCP,
     IPv6-UDP),	MSI-X interrupts, TCP Segmentation Offload (TSO), Large
     Receive Offload (LRO), and	Receive	Side Scaling (RSS).

     The bxe driver provides support for various NICs based on the Broadcom
     NetXtreme II family of 10Gb Ethernet controller chips, including the fol-

     +o	 Broadcom NetXtreme II BCM57710	10Gb
     +o	 Broadcom NetXtreme II BCM57711	10Gb
     +o	 Broadcom NetXtreme II BCM57711E 10Gb
     +o	 Broadcom NetXtreme II BCM57712	10Gb
     +o	 Broadcom NetXtreme II BCM57712-MF 10Gb
     +o	 Broadcom NetXtreme II BCM57800	10Gb
     +o	 Broadcom NetXtreme II BCM57800-MF 10Gb
     +o	 Broadcom NetXtreme II BCM57810	10Gb
     +o	 Broadcom NetXtreme II BCM57810-MF 10Gb
     +o	 Broadcom NetXtreme II BCM57840	10Gb / 20Gb
     +o	 Broadcom NetXtreme II BCM57840-MF 10Gb

     There a number of configuration parameters	that can be set	to tweak the
     driver's behavior.	 These parameters can be set via the loader.conf(5)
     file to take affect during	the next system	boot.  The following parame-
     ters affect ALL instances of the driver.

	     DEFAULT = 0
	     Sets the default logging level of the driver.  See	the Diagnos-
	     tics and Debugging	section	below for more details.

	     DEFAULT = 2
	     Sets the default interrupt	mode: 0=IRQ, 1=MSI, 2=MSIX.  If	set to
	     MSIX and allocation fails,	the driver will	roll back and attempt
	     MSI allocation.  If MSI allocation	fails, the driver will roll
	     back and attempt fixed level IRQ allocation.  If IRQ allocation
	     fails, then the driver load fails.	 With MSI/MSIX,	the driver
	     attempts to allocate a vector for each queue in addition to one
	     more for default processing.

	     DEFAULT = 4
	     Sets the default number of	fast path packet processing queues.
	     Note that one MSI/MSIX interrupt vector is	allocated per-queue.

	     DEFAULT = 0
	     Sets the maximum number of	receive	buffers	to allocate per-queue.
	     Zero(0) means to allocate a receive buffer	for every buffer
	     descriptor.  By default this equates to 4080 buffers per-queue
	     which is the maximum value	for this config	parameter.

	     DEFAULT = 25
	     Sets the number of	ticks for host interrupt coalescing in the
	     receive path.

	     DEFAULT = 50
	     Sets the number of	ticks for host interrupt coalescing in the
	     transmit path.

	     DEFAULT = 0xffffffff
	     Sets the maximum number of	receive	packets	to process in an
	     interrupt.	 If the	budget is reached then the remaining/pending
	     packets will be processed in a scheduled taskqueue.

	     DEFAULT = 32768
	     Sets the maximum LRO aggregration byte size.  The higher the
	     value the more packets the	hardware will aggregate.  Maximum is

	     DEFAULT = -1
	     Sets the PCI MRRS:	-1=Auto, 0=128B, 1=256B, 2=512B, 3=1KB

	     DEFAULT = 0

	     DEFAULT = 0
	     Enable/Disable 4-tuple RSS	for UDP: 0=DISABLED, 1=ENABLED

     Special care must be taken	when modifying the number of queues and
     receive buffers.  FreeBSD imposes a limit on the maximum number of
     mbuf(9) allocations.  If buffer allocations fail, the interface initial-
     ization will fail and the interface will not be usable.  The driver does
     not make a	best effort for	buffer allocations.  It	is an all or nothing

     You can tweak the mbuf(9) allocation limit	using sysctl(8)	and view the
     current usage with	netstat(1) as follows:

	   # netstat -m
	   # sysctl kern.ipc.nmbclusters
	   # sysctl kern.ipc.nmbclusters=<#>

     There are additional configuration	parameters that	can be set on a	per-
     instance basis to dynamically override the	default	configuration.	The
     '#' below must be replaced	with the driver	instance / interface unit num-

	     DEFAULT = 0
	     Sets the default logging level of the driver instance.  See
	     hw.bxe.debug above	and the	Diagnostics and	Debugging section
	     below for more details.

	     DEFAULT = 0xffffffff
	     Sets the maximum number of	receive	packets	to process in an
	     interrupt for the driver instance.	 See hw.bxe.rx_budget above
	     for more details.

     Additional	items can be configured	using ifconfig(8):

     MTU - Maximum Transmission	Unit
	     DEFAULT = 1500
	     RANGE = 46-9184
	     # ifconfig	bxe# mtu <n>

     Promiscuous Mode
	     # ifconfig	bxe# [ promisc | -promisc ]

     Rx/Tx Checksum Offload
	     Note that the Rx and Tx settings are not independent.
	     # ifconfig	bxe# [ rxcsum |	-rxcsum	| txcsum | -txcsum ]

     TSO - TCP Segmentation Offload
	     DEFAULT = ON
	     # ifconfig	bxe# [ tso | -tso | tso6 | -tso6 ]

     LRO - TCP Large Receive Offload
	     DEFAULT = ON
	     # ifconfig	bxe# [ lro | -lro ]

     There are many statistics exposed by bxe via sysctl(8).

     To	dump the default driver	configuration:

	   # sysctl -a | grep hw.bxe

     To	dump every instance's configuration and	detailed statistics:

	   # sysctl -a | grep dev.bxe

     To	dump information for a single instance (replace	the '#'	with the
     driver instance / interface unit number):

	   # sysctl -a | grep dev.bxe.#

     To	dump information for all the queues of a single	instance:

	   # sysctl -a | grep dev.bxe.#.queue

     To	dump information for a single queue of a single	instance (replace the
     additional	'#' with the queue number):

	   # sysctl -a | grep dev.bxe.#.queue.#

     The bxe driver has	the ability to dump a ton of debug messages to the
     system log.  The default level of logging can be set with the
     hw.bxe.debug sysctl(8).  Take care	with this setting as it	can result in
     too many logs being dumped.  Since	this parameter is the default one, it
     affects every instance and	will dramatically change the timing in the
     driver.  A	better alternative to aid in debugging is to dynamically
     change the	debug level of a specific instance with	the dev.bxe.#.debug
     sysctl(8).	 This allows you to turn on/off	logging	of various debug
     groups on-the-fly.

     The different debug groups	that can be toggled are:

	   DBG_LOAD   0x00000001 /* load and unload    */
	   DBG_INTR   0x00000002 /* interrupt handling */
	   DBG_SP     0x00000004 /* slowpath handling  */
	   DBG_STATS  0x00000008 /* stats updates      */
	   DBG_TX     0x00000010 /* packet transmit    */
	   DBG_RX     0x00000020 /* packet receive     */
	   DBG_PHY    0x00000040 /* phy/link handling  */
	   DBG_IOCTL  0x00000080 /* ioctl handling     */
	   DBG_MBUF   0x00000100 /* dumping mbuf info  */
	   DBG_REGS   0x00000200 /* register access    */
	   DBG_LRO    0x00000400 /* lro	processing     */
	   DBG_ASSERT 0x80000000 /* debug assert       */
	   DBG_ALL    0xFFFFFFFF /* flying monkeys     */

     For example, to debug an issue in the receive path	on bxe0:

	   # sysctl dev.bxe.0.debug=0x22

     When finished turn	the logging back off:

	   # sysctl dev.bxe.0.debug=0

     netstat(1), altq(4), arp(4), netintro(4), ng_ether(4), vlan(4),

     The bxe device driver first appeared in FreeBSD 9.0.

     The bxe driver was	written	by Eric	Davis <>,
     David Christensen <>, and
     Gary Zambrano <>.

FreeBSD	10.1			April 29, 2012			  FreeBSD 10.1


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