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Diffstat (limited to 'static/freebsd/man4/ntb_hw_intel.4')
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diff --git a/static/freebsd/man4/ntb_hw_intel.4 b/static/freebsd/man4/ntb_hw_intel.4 new file mode 100644 index 00000000..cc22cd96 --- /dev/null +++ b/static/freebsd/man4/ntb_hw_intel.4 @@ -0,0 +1,98 @@ +.\" +.\" Copyright (c) 2016-2017 Alexander Motin <mav@FreeBSD.org> +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.Dd October 11, 2020 +.Dt NTB_HW_INTEL 4 +.Os +.Sh NAME +.Nm ntb_hw_intel +.Nd Intel(R) Non-Transparent Bridge driver +.Sh SYNOPSIS +To compile this driver into your kernel, +place the following lines in your kernel configuration file: +.Bd -ragged -offset indent +.Cd "device ntb" +.Cd "device ntb_hw_intel" +.Ed +.Pp +Or, to load the driver as a module at boot, place the following line in +.Xr loader.conf 5 : +.Bd -literal -offset indent +ntb_hw_intel_load="YES" +.Ed +.Sh DESCRIPTION +The +.Nm ntb_hw_intel +driver provides support for the Non-Transparent Bridge (NTB) hardware in +Intel Xeon E3/E5 and S1200 processor families, which allow one of their PCIe +ports to be switched from transparent to non-transparent bridge mode. +In this mode the bridge looks not like a PCI bridge, but like a PCI endpoint +device. +The driver hides hardware details, exposing memory windows, scratchpads +and doorbells of the other side via a hardware independent KPI to the +.Xr ntb 4 +subsystem. +.Pp +The hardware provides 2 or 3 memory windows to the other system's memory, +16 scratchpad registers and 14, 31 or 34 doorbells to interrupt the other +system, depending on the platform. +On Xeon processors one of the memory windows is typically consumed by the driver +itself to work around multiple hardware errata. +.Sh CONFIGURATION +The NTB configuration should be set by BIOS. +It includes enabling NTB, choosing between NTB-to-NTB (back-to-back) or +NTB-to-Root Port mode, +enabling split BAR mode (one of two 64-bit BARs can be split into two 32-bit +ones) and configuring BAR sizes in bits (from 12 to 29/39) for both NTB sides. +.Pp +The recommended configuration is NTB-to-NTB mode, split bar enabled and +all BAR sizes set to 20 (1 MiB). +This needs to be done on both systems. +Note, on Xeon SkyLake and newer platforms, split bar mode is not available. +.Sh SEE ALSO +.Xr if_ntb 4 , +.Xr ntb 4 , +.Xr ntb_transport 4 +.Sh AUTHORS +.An -nosplit +The +.Nm +driver was developed by Intel and originally written by +.An Carl Delsey Aq Mt carl@FreeBSD.org . +Later improvements were done by +.An Conrad E. Meyer Aq Mt cem@FreeBSD.org +and +.An Alexander Motin Aq Mt mav@FreeBSD.org . +.Sh BUGS +NTB-to-Root Port mode is not yet supported, but it doesn't look very useful. +.Pp +On Xeon v2/v3/v4 processors split BAR mode should be enabled to allow +SB01BASE_LOCKUP errata workaround to be applied by the driver. +.Pp +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 access on the other system can read or write to +any location on your system. +In other words, only connect two systems that completely trust each other. |