nvdimm: allow exposing RAM carveouts as NVDIMM DIMM devices

Browse source

There are use cases, for example virtual machine hosts, that create
"persistent" memory regions using memmap= option on x86 or dummy
pmem-region device tree nodes on DT based systems.

Both these options are inflexible because they create static regions and
the layout of the "persistent" memory cannot be adjusted without reboot
and sometimes they even require firmware update.

Add a ramdax driver that allows creation of DIMM devices on top of
E820_TYPE_PRAM regions and devicetree pmem-region nodes.

The DIMMs support label space management on the "device" and provide a
flexible way to access RAM using fsdax and devdax.

Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://patch.msgid.link/20251026153841.752061-2-rppt@kernel.org
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

...

This commit is contained in:

Mike Rapoport (Microsoft) 2025-10-26 17:38:41 +02:00 • committed by Ira Weiny

parent 6146a0f1df

commit 43bc0aa19a

3 changed files with 302 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

19

drivers/nvdimm/Kconfig

View file

1

drivers/nvdimm/Makefile

View file

282

drivers/nvdimm/ramdax.c

View file