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NTB_HW_PLX(4)		 BSD Kernel Interfaces Manual		 NTB_HW_PLX(4)

NAME
     ntb_hw_plx	-- PLX/Avago/Broadcom Non-Transparent Bridge driver

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

	   device ntb
	   device ntb_hw_plx

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

	   ntb_hw_plx_load="YES"

     The following tunables are	settable from the loader(8):

     hint.ntb_hw.X.b2b
     Being set to 1 (default) tells the	driver attached	to Virtual Interface
     of	the NTB	that it	works in NTB-to-NTB (back-to-back) mode, 0 -- NTB-to-
     Root Port.	 Driver	attached to Link Interface (visible from Root Port
     side) switches to NTB-to-Root Port	mode automatically, but	one attached
     to	Virtual	Interface can't	detect what is on the other side and require
     external knowledge.

DESCRIPTION
     The ntb_hw_plx driver provides support for	the Non-Transparent Bridge
     (NTB) hardware in PLX PCIe	bridge chips, which allow up to	two of their
     PCIe ports	to be switched from transparent	to non-transparent bridge
     mode.  In this mode bridge	looks not as a PCI bridge, but as PCI endpoint
     device.  The driver hides hardware	details, exposing memory windows,
     scratchpads and doorbells of the other side via hardware independent KPI
     to	ntb(4) subsystem.

     Each PLX NTB provides up to 2 64-bit or 4 32-bit memory windows to	the
     other system's memory, 6 or 12 scratchpad registers and 16	doorbells to
     interrupt the other system.  In NTB-to-NTB	mode one of memory windows (or
     half of it, if bigger then	1MB) is	consumed by the	driver itself to ac-
     cess scratchpad and doorbell registers of the other side.

HARDWARE
     The following PLX/Avago/Broadcom chips are	supported by the ntb_hw_plx
     driver:

     +o	 PEX 8713
     +o	 PEX 8717
     +o	 PEX 8725
     +o	 PEX 8733
     +o	 PEX 8749

     , but it may also work with other compatible ones.

CONFIGURATION
     The basic chip configuration should be done by serial EEPROM or via i2c.
     It	includes enabling NTB on one or	both sides (choosing between NTB-to-
     NTB (back-to-back)	and NTB-to-Root	Port modes) and	configuring BARs
     sizes.

     The recommended mode is NTB-to-NTB	mode, since while NTB-to-Root Port is
     generally supported by the	driver,	it require PCI hotplug handling	on the
     Root Port,	that may be difficult or cause different kinds of problems.

SEE ALSO
     if_ntb(4),	ntb_transport(4), ntb(4),

AUTHORS
     The ntb_hw_plx driver was written by Alexander Motin <mav@FreeBSD.org>.

BUGS
     There is no way to	protect	your system from malicious behavior on the
     other system once the link	is brought up.	Anyone with root or kernel ac-
     cess on the other system can read or write	to any location	on your	sys-
     tem.  In other words, only	connect	two systems that completely trust each
     other.

BSD				August 30, 2017				   BSD

NAME | SYNOPSIS | DESCRIPTION | HARDWARE | CONFIGURATION | SEE ALSO | AUTHORS | BUGS

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