Index: head/share/man/man4/nvdimm.4
===================================================================
--- head/share/man/man4/nvdimm.4	(revision 351896)
+++ head/share/man/man4/nvdimm.4	(revision 351897)
@@ -1,122 +1,134 @@
 .\" Copyright (c) 2019 The FreeBSD Foundation, Inc.
 .\"
 .\" This documentation was written by
 .\" Konstantin Belousov <kib@FreeBSD.org> under sponsorship
 .\" from the FreeBSD Foundation.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
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 .\"    notice, this list of conditions and the following disclaimer in the
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 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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)
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 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 .\"
 .\" $FreeBSD$
 .\"
-.Dd August 23, 2019
+.Dd September 5, 2019
 .Dt NVDIMM 4
 .Os
 .Sh NAME
 .Nm nvdimm
 .Nd ACPI NVDIMM driver
 .Sh SYNOPSIS
 To load the driver as a module at boot, place the following line in
 .Xr loader.conf 5 :
 .Bd -literal -offset indent
 nvdimm_load="YES"
 .Ed
 .Sh DESCRIPTION
 .Bf -symbolic
 Note:
 The
 .Nm
 driver is under development and has some important limitations
 described below.
 .Ef
 .Pp
 The
 .Nm
 driver provides access to Non-Volatile DIMM (NVDIMM) persistent memory
 devices, which are ACPI-enumerated under the root NVDIMM device
 with a
 .Va _HID
 of
 .Dv ACPI0012
 and in the
 .Dv NFIT
 table.
 .Pp
 For each System Physical Address (SPA) Range described by NFIT, a
 device node
 .Pa /dev/nvdimm_spaNNN
 is created, where
 .Dv NNN
 is the SPA position in the table.
 The node can be used to
 .Xr read 2 ,
 .Xr write 2 ,
 or
 .Xr mmap 2
 the device.
 .Pp
 Also, for each SPA, the geom provider
 .Pa spaNNN
-is created, which can be used to create a conventional filesystem (e.g.
+is created, which can be used to create a conventional filesystem (e.g.,
 by
 .Xr newfs 8 )
 and
 .Xr mount 8
 it as any storage volume.
 Content accessible by
 .Pa /dev/nvdimm_spaNNN
 and
 .Pa /dev/spaNNN
 is coherent.
+.Pp
+The
+.Nm
+driver has support for reading NVDIMM namespaces (if supported by your
+hardware and already configured by some other mechanism, e.g., a BIOS
+configuration screen).
+The driver will provide a
+.Pa /dev/nvdimm_spaNNNnsMMM
+device node and
+.Pa spaNNNnsMMM
+geom provider for each namespace in a SPA, which behave analogously to their
+full-SPA cousins described above.
 .Sh SEE ALSO
 .Xr ACPI 4 ,
 .Xr GEOM 4 ,
 .Xr geom 8 ,
 .Xr mount 8 ,
 .Xr newfs 8 ,
 .Xr disk 9
 .Sh HISTORY
 The
 .Nm
 driver first appeared in
 .Fx 12.0 .
 .Sh AUTHORS
 .An -nosplit
 The
 .Nm
 driver was originally written by
 .An Konstantin Belousov Aq Mt kib@FreeBSD.org ,
 and then updated by
 .An D. Scott Phillips Aq Mt scottph@FreeBSD.org .
 .Sh BUGS
 The
 .Nm
 driver does not utilize the Block Window interface, so if the write to
 NVDIMM was interrupted due to a system crash or power outage,
 the corresponding page might be left in partially updated state.
 .Pp
 There is no support for Device-Specific Methods (DSM), used to report and
 control the device health and wearing.
 .Pp
 The driver depends on the
 .Xr pmap_largemap 9
 pmap interface, which is currently only implemented on amd64.
 The interface can be only reasonable implemented on 64bit architectures.