linux-toradex.git/drivers/nvdimm/Kconfig, branch master Linux kernel for Apalis and Colibri modules nvdimm: allow exposing RAM carveouts as NVDIMM DIMM devices 2025-11-03T20:50:42+00:00 Mike Rapoport (Microsoft) rppt@kernel.org 2025-10-26T15:38:41+00:00 43bc0aa19a2174d8eec711d9f3bf941a7b81373c 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> 
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>
libnvdimm: Fix ACPI_NFIT in BLK_DEV_PMEM help 2024-02-12T21:32:25+00:00 Peter Robinson pbrobinson@gmail.com 2024-02-12T12:37:10+00:00 e4b0925fcc89c4267b55c25acc254c041f5ccb21 The ACPI_NFIT config option is described incorrectly as the inverse NFIT_ACPI, which doesn't exist, so update the help to the actual config option. Signed-off-by: Peter Robinson <pbrobinson@gmail.com> Link: https://lore.kernel.org/r/20240212123716.795996-1-pbrobinson@gmail.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> 
The ACPI_NFIT config option is described incorrectly as the
inverse NFIT_ACPI, which doesn't exist, so update the help
to the actual config option.

Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Link: https://lore.kernel.org/r/20240212123716.795996-1-pbrobinson@gmail.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
nvdimm: Support sizeof(struct page) > MAX_STRUCT_PAGE_SIZE 2023-01-28T23:32:36+00:00 Dan Williams dan.j.williams@intel.com 2023-01-25T20:23:46+00:00 c91d713630848460de8669e6570307b7e559863b Commit 6e9f05dc66f9 ("libnvdimm/pfn_dev: increase MAX_STRUCT_PAGE_SIZE") ...updated MAX_STRUCT_PAGE_SIZE to account for sizeof(struct page) potentially doubling in the case of CONFIG_KMSAN=y. Unfortunately this doubles the amount of capacity stolen from user addressable capacity for everyone, regardless of whether they are using the debug option. Revert that change, mandate that MAX_STRUCT_PAGE_SIZE never exceed 64, but allow for debug scenarios to proceed with creating debug sized page maps with a compile option to support debug scenarios. Note that this only applies to cases where the page map is permanent, i.e. stored in a reservation of the pmem itself ("--map=dev" in "ndctl create-namespace" terms). For the "--map=mem" case, since the allocation is ephemeral for the lifespan of the namespace, there are no explicit restriction. However, the implicit restriction, of having enough available "System RAM" to store the page map for the typically large pmem, still applies. Fixes: 6e9f05dc66f9 ("libnvdimm/pfn_dev: increase MAX_STRUCT_PAGE_SIZE") Cc: <stable@vger.kernel.org> Cc: Alexander Potapenko <glider@google.com> Cc: Marco Elver <elver@google.com> Reported-by: Jeff Moyer <jmoyer@redhat.com> Acked-by: Yu Zhao <yuzhao@google.com> Link: https://lore.kernel.org/r/167467815773.463042.7022545814443036382.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
Commit 6e9f05dc66f9 ("libnvdimm/pfn_dev: increase MAX_STRUCT_PAGE_SIZE")

...updated MAX_STRUCT_PAGE_SIZE to account for sizeof(struct page)
potentially doubling in the case of CONFIG_KMSAN=y. Unfortunately this
doubles the amount of capacity stolen from user addressable capacity for
everyone, regardless of whether they are using the debug option. Revert
that change, mandate that MAX_STRUCT_PAGE_SIZE never exceed 64, but
allow for debug scenarios to proceed with creating debug sized page maps
with a compile option to support debug scenarios.

Note that this only applies to cases where the page map is permanent,
i.e. stored in a reservation of the pmem itself ("--map=dev" in "ndctl
create-namespace" terms). For the "--map=mem" case, since the allocation
is ephemeral for the lifespan of the namespace, there are no explicit
restriction. However, the implicit restriction, of having enough
available "System RAM" to store the page map for the typically large
pmem, still applies.

Fixes: 6e9f05dc66f9 ("libnvdimm/pfn_dev: increase MAX_STRUCT_PAGE_SIZE")
Cc: <stable@vger.kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Reported-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Yu Zhao <yuzhao@google.com>
Link: https://lore.kernel.org/r/167467815773.463042.7022545814443036382.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
libnvdimm: Introduce CONFIG_NVDIMM_SECURITY_TEST flag 2022-12-01T20:42:35+00:00 Dave Jiang dave.jiang@intel.com 2022-11-30T19:23:07+00:00 15a8348707ffd2a37516db9bede88cc0bb467e0b nfit_test overrode the security_show() sysfs attribute function in nvdimm dimm_devs in order to allow testing of security unlock. With the introduction of CXL security commands, the trick to override security_show() becomes significantly more complicated. By introdcing a security flag CONFIG_NVDIMM_SECURITY_TEST, libnvdimm can just toggle the check via a compile option. In addition the original override can can be removed from tools/testing/nvdimm/. The flag will also be used to bypass cpu_cache_invalidate_memregion() when set in a different commit. This allows testing on QEMU with nfit_test or cxl_test since cpu_cache_has_invalidate_memregion() checks whether X86_FEATURE_HYPERVISOR cpu feature flag is set on x86. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/166983618758.2734609.18031639517065867138.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
nfit_test overrode the security_show() sysfs attribute function in nvdimm
dimm_devs in order to allow testing of security unlock. With the
introduction of CXL security commands, the trick to override
security_show() becomes significantly more complicated. By introdcing a
security flag CONFIG_NVDIMM_SECURITY_TEST, libnvdimm can just toggle the
check via a compile option. In addition the original override can can be
removed from tools/testing/nvdimm/.

The flag will also be used to bypass cpu_cache_invalidate_memregion() when
set in a different commit. This allows testing on QEMU with nfit_test or
cxl_test since cpu_cache_has_invalidate_memregion() checks whether
X86_FEATURE_HYPERVISOR cpu feature flag is set on x86.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/166983618758.2734609.18031639517065867138.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
nvdimm/blk: Delete the block-aperture window driver 2022-03-11T23:53:12+00:00 Dan Williams dan.j.williams@intel.com 2022-03-10T03:49:26+00:00 f8669f1d6a86a6b17104ceca9340ded280307ac1 Block Aperture Window support was an attempt to layer an error model over PMEM for platforms that did not support machine-check-recovery. However, it was abandoned before it ever shipped, and only ever existed in the ACPI specification. Meanwhile Linux has carried a large pile of dead code for non-shipping infrastructure. For years it has been off to the side out of the way, but now CXL and recent directions with DAX support have the potential to collide with this code. In preparation for adding discontiguous namespace support, a pre-requisite for the nvdimm subsystem to replace device-mapper for striping + concatenation use cases, delete BLK aperture support. On the obscure chance that some hardware vendor shipped support for this mode, note that the driver will still keep BLK space reserved in the label area. So an end user in this case would still have the opportunity to report the regression to get BLK-mode support restored without risking the data they have on that device. Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/164688416668.2879318.16903178375774275120.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
Block Aperture Window support was an attempt to layer an error model
over PMEM for platforms that did not support machine-check-recovery.
However, it was abandoned before it ever shipped, and only ever existed
in the ACPI specification. Meanwhile Linux has carried a large pile of
dead code for non-shipping infrastructure. For years it has been off to
the side out of the way, but now CXL and recent directions with DAX
support have the potential to collide with this code.

In preparation for adding discontiguous namespace support, a
pre-requisite for the nvdimm subsystem to replace device-mapper for
striping + concatenation use cases, delete BLK aperture support.

On the obscure chance that some hardware vendor shipped support for this
mode, note that the driver will still keep BLK space reserved in the
label area. So an end user in this case would still have the opportunity
to report the regression to get BLK-mode support restored without
risking the data they have on that device.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/164688416668.2879318.16903178375774275120.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
dax: remove CONFIG_DAX_DRIVER 2021-12-04T16:58:51+00:00 Christoph Hellwig hch@lst.de 2021-11-29T10:21:37+00:00 afd586f0d06ce3d81b7c474499630fec88833828 CONFIG_DAX_DRIVER only selects CONFIG_DAX now, so remove it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/20211129102203.2243509-4-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
CONFIG_DAX_DRIVER only selects CONFIG_DAX now, so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/20211129102203.2243509-4-hch@lst.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
lib: Uplevel the pmem "region" ida to a global allocator 2019-11-07T14:44:29+00:00 Dan Williams dan.j.williams@intel.com 2019-11-07T01:43:31+00:00 33dd70752cd76f4d883a165a674f13121a4155ed In preparation for handling platform differentiated memory types beyond persistent memory, uplevel the "region" identifier to a global number space. This enables a device-dax instance to be registered to any memory type with guaranteed unique names. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
In preparation for handling platform differentiated memory types beyond
persistent memory, uplevel the "region" identifier to a global number
space. This enables a device-dax instance to be registered to any memory
type with guaranteed unique names.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
libnvdimm: Enable unit test infrastructure compile checks 2019-09-07T07:28:05+00:00 Dan Williams dan.j.williams@intel.com 2019-09-04T22:43:31+00:00 62974fc389b364d8af70e044836362222bd3ae53 The infrastructure to mock core libnvdimm routines for unit testing purposes is prone to bitrot relative to refactoring of that core. Arrange for the unit test core to be built when CONFIG_COMPILE_TEST=y. This does not result in a functional unit test environment, it is only a helper for 0day to catch unit test build regressions. Note that there are a few x86isms in the implementation, so this does not bother compile testing this architectures other than 64-bit x86. Link: https://lore.kernel.org/r/156763690875.2556198.15786177395425033830.stgit@dwillia2-desk3.amr.corp.intel.com Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> 
The infrastructure to mock core libnvdimm routines for unit testing
purposes is prone to bitrot relative to refactoring of that core.  Arrange
for the unit test core to be built when CONFIG_COMPILE_TEST=y.  This does
not result in a functional unit test environment, it is only a helper for
0day to catch unit test build regressions.

Note that there are a few x86isms in the implementation, so this does not
bother compile testing this architectures other than 64-bit x86.

Link: https://lore.kernel.org/r/156763690875.2556198.15786177395425033830.stgit@dwillia2-desk3.amr.corp.intel.com
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
docs: nvdimm: add it to the driver-api book 2019-07-15T12:20:27+00:00 Mauro Carvalho Chehab mchehab+samsung@kernel.org 2019-06-18T19:32:31+00:00 ae4a05027e2f883fb5f822e48d67cacc26bf60e1 The descriptions here are from Kernel driver's PoV. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Dan Williams <dan.j.williams@intel.com> 
The descriptions here are from Kernel driver's PoV.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>
docs: nvdimm: convert to ReST 2019-07-15T12:20:25+00:00 Mauro Carvalho Chehab mchehab+samsung@kernel.org 2019-04-18T17:21:14+00:00 b0a4aa950c68b5010831ecfc450510c64e4d80ba Rename the nvdimm documentation files to ReST, add an index for them and adjust in order to produce a nice html output via the Sphinx build system. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Dan Williams <dan.j.williams@intel.com> 
Rename the nvdimm documentation files to ReST, add an
index for them and adjust in order to produce a nice html
output via the Sphinx build system.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>