135 lines
3.7 KiB
Groff
135 lines
3.7 KiB
Groff
.\" 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
|
|
.\" 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 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)
|
|
.\" 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 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.,
|
|
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 a write to an
|
|
NVDIMM is interrupted due to a system crash or power outage,
|
|
the corresponding page might be left in a partially updated state.
|
|
.Pp
|
|
There is no support for Device-Specific Methods (DSM), used to report and
|
|
control 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.
|