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head/share/man/man4/ntb_hw_amd.4
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| svn:eol-style | null | native \ No newline at end of property |
| svn:keywords | null | FreeBSD=%H \ No newline at end of property |
| svn:mime-type | null | text/plain \ No newline at end of property |
| .\" | |||||
| .\" Copyright (c) 2019 Rajesh Kumar <rajesh1.kumar@amd.com> | |||||
| .\" 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. | |||||
| .\" | |||||
| .\" $FreeBSD$ | |||||
| .\" | |||||
| .Dd August 29, 2019 | |||||
| .Dt NTB_HW_AMD 4 | |||||
| .Os | |||||
| .Sh NAME | |||||
| .Nm ntb_hw_amd | |||||
| .Nd AMD 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_amd" | |||||
| .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_amd_load="YES" | |||||
| .Ed | |||||
| .Pp | |||||
| The following sysctls are supported in this driver | |||||
| .Bl -ohang | |||||
| .It Va dev.ntb_hw.X.info | |||||
| Reading this sysctl will give the basic details like the number of memory | |||||
| windows, scratchpads and doorbells exposed by the NTB on the local host to | |||||
| access the devices beyond the bridge. | |||||
| It also provides details about the masked doorbells, translation address and | |||||
| size limit of each exposed memory window and link status information. | |||||
| .El | |||||
| .Sh DESCRIPTION | |||||
| The | |||||
| .Nm ntb_hw_amd | |||||
| driver provides support for the Non-Transparent Bridge (NTB) hardware in | |||||
| AMD EPYC processor family. | |||||
| The Non-Transparent Bridge does not look as a regular PCI bridge, but as PCI | |||||
| endpoint device, hiding the devices behind it. | |||||
| The driver hides details of hardware on the other side, but exposes memory windows, | |||||
| scratchpads and doorbells to access the other side via hardware independent | |||||
| KPI to | |||||
| .Xr ntb 4 | |||||
| subsystem. | |||||
| .Pp | |||||
| The hardware provides 2 (both 64-bit) or 3 (one 32-bit and two 64-bit) memory | |||||
| windows to the other system's memory, up to 16 scratchpad registers and 16 | |||||
| doorbells to communicate with and interrupt the other system respectively. | |||||
| .Sh CONFIGURATION | |||||
| The NTB configuration should be set by BIOS. | |||||
| This includes enabling NTB, choosing topology (only NTB-to-Root Port | |||||
| mode is supported now), role of the host in the topology. | |||||
| This needs to be done on both systems. | |||||
| .Pp | |||||
| The BAR size for memory windows is configured to 1 MiB by default. | |||||
| .Sh SEE ALSO | |||||
| .Xr if_ntb 4 , | |||||
| .Xr ntb 4 , | |||||
| .Xr ntb_transport 4 | |||||
| .Sh AUTHORS | |||||
| .An -nosplit | |||||
| The | |||||
| .Nm | |||||
| driver was developed by AMD and originally written by | |||||
| .An Rajesh Kumar Aq Mt rajesh1.kumar@amd.com . | |||||
| Reviewed by | |||||
| .An Alexander Motin Aq Mt mav@FreeBSD.org , | |||||
| .An Conrad E. Meyer Aq Mt cem@FreeBSD.org | |||||
| and | |||||
| .An Warner Losh Aq Mt imp@FreeBSD.org . | |||||