Differential D26683 Diff 78635 head/share/man/man4/ntb_hw_intel.4

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head/share/man/man4/ntb_hw_intel.4

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	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)			.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT			.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY			.\" 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			.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	.\" SUCH DAMAGE.			.\" SUCH DAMAGE.
	.\"			.\"
	.\" $FreeBSD$			.\" $FreeBSD$
	.\"			.\"
	.Dd August 30, 2017			.Dd October 11, 2020
	.Dt NTB_HW_INTEL 4			.Dt NTB_HW_INTEL 4
	.Os			.Os
	.Sh NAME			.Sh NAME
	.Nm ntb_hw_intel			.Nm ntb_hw_intel
	.Nd Intel(R) Non-Transparent Bridge driver			.Nd Intel(R) Non-Transparent Bridge driver
	.Sh SYNOPSIS			.Sh SYNOPSIS
	To compile this driver into your kernel,			To compile this driver into your kernel,
	place the following lines in your kernel configuration file:			place the following lines in your kernel configuration file:
	.Bd -ragged -offset indent			.Bd -ragged -offset indent
	.Cd "device ntb"			.Cd "device ntb"
	.Cd "device ntb_hw_intel"			.Cd "device ntb_hw_intel"
	.Ed			.Ed
	.Pp			.Pp
	Or, to load the driver as a module at boot, place the following line in			Or, to load the driver as a module at boot, place the following line in
	.Xr loader.conf 5 :			.Xr loader.conf 5 :
	.Bd -literal -offset indent			.Bd -literal -offset indent
	ntb_hw_intel_load="YES"			ntb_hw_intel_load="YES"
	.Ed			.Ed
	.Sh DESCRIPTION			.Sh DESCRIPTION
	The			The
	.Nm ntb_hw_intel			.Nm ntb_hw_intel
	driver provides support for the Non-Transparent Bridge (NTB) hardware in			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			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.			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.			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			The driver hides hardware details, exposing memory windows, scratchpads
	and doorbells of the other side via hardware independent KPI to			and doorbells of the other side via a hardware independent KPI to the
	.Xr ntb 4			.Xr ntb 4
	subsystem.			subsystem.
	.Pp			.Pp
	The hardware provides 2 or 3 memory windows to the other system's memory,			The hardware provides 2 or 3 memory windows to the other system's memory,
	16 scratchpad registers and 14 or 34 doorbells to interrupt the other system.			16 scratchpad registers and 14, 31 or 34 doorbells to interrupt the other
	On Xeon processors one of memory windows is typically consumed by the driver			system, depending on the platform.
	itself to workaround multiple hardware erratas.			On Xeon processors one of the memory windows is typically consumed by the driver
				itself to work around multiple hardware errata.
	.Sh CONFIGURATION			.Sh CONFIGURATION
	The NTB configuration should be set by BIOS.			The NTB configuration should be set by BIOS.
	It includes enabling NTB, choosing between NTB-to-NTB (back-to-back) or			It includes enabling NTB, choosing between NTB-to-NTB (back-to-back) or
	NTB-to-Root Port mode,			NTB-to-Root Port mode,
	enabling split BAR mode (one of two 64-bit BARs can be split into two 32-bit			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.			ones) and configuring BAR sizes in bits (from 12 to 29/39) for both NTB sides.
	.Pp			.Pp
	The recommended configuration is NTB-to-NTB mode, split bar is enabled and			The recommended configuration is NTB-to-NTB mode, split bar enabled and
	all BAR sizes are set to 20 (1 MiB).			all BAR sizes set to 20 (1 MiB).
	This needs to be done on both systems.			This needs to be done on both systems.
				Note, on Xeon SkyLake and newer platforms, split bar mode is not available.
	.Sh SEE ALSO			.Sh SEE ALSO
	.Xr if_ntb 4 ,			.Xr if_ntb 4 ,
	.Xr ntb_transport 4 ,			.Xr ntb_transport 4 ,
	.Xr ntb 4 ,			.Xr ntb 4 ,
	.Sh AUTHORS			.Sh AUTHORS
	.An -nosplit			.An -nosplit
	The			The
	.Nm			.Nm
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