libnvdimm: Fix ACPI_NFIT in BLK_DEV_PMEM help

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

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

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

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

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

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

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

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

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>

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

acpi/nfit, libnvdimm: Add unlock of nvdimm support for Intel DIMMs

Add support to unlock the dimm via the kernel key management APIs. The
passphrase is expected to be pulled from userspace through keyutils.
The key management and sysfs attributes are libnvdimm generic.

Encrypted keys are used to protect the nvdimm passphrase at rest. The
master key can be a trusted-key sealed in a TPM, preferred, or an
encrypted-key, more flexible, but more exposure to a potential attacker.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Revert "libnvdimm, of_pmem: workaround OF_NUMA=n build error"

With commit df3f126482db ("libnvdimm, of_pmem: use dev_to_node() instead
of of_node_to_nid()") it is now possible to allow of_pmem to be built as
a module as originally implemented.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

libnvdimm, of_pmem: workaround OF_NUMA=n build error

Stephen reports that an x86 allmodconfig build fails to build the
of_pmem driver due to a missing definition of of_node_to_nid(). That
helper is currently only exported in the OF_NUMA=y case. In other cases,
ppc and sparc, it is a weak symbol, and outside of those platforms it is
a static inline.

Until an OF_NUMA=n configuration can reliably support usage of
of_node_to_nid() in modules across architectures, mark this driver as
'bool' instead of 'tristate'.

Cc: Rob Herring <robh@kernel.org>
Cc: Oliver O'Halloran <oohall@gmail.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

libnvdimm: Add device-tree based driver

This patch adds peliminary device-tree bindings for persistent memory
regions. The driver registers a libnvdimm bus for each pmem-region
node and each address range under the node is converted to a region
within that bus.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

dax: introduce CONFIG_DAX_DRIVER

In support of allowing device-mapper to compile out idle/dead code when
there are no dax providers in the system, introduce the DAX_DRIVER
symbol. This is selected by all leaf drivers that device-mapper might be
layered on top. This allows device-mapper to conditionally 'select DAX'
only when a provider is present.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Reported-by: Bart Van Assche <Bart.VanAssche@wdc.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

treewide: Fix typos in Kconfig

This patch fixes some spelling typos found in Kconfig files.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

pmem: add dax_operations support

Setup a dax_device to have the same lifetime as the pmem block device
and add a ->direct_access() method that is equivalent to
pmem_direct_access(). Once fs/dax.c has been converted to use
dax_operations the old pmem_direct_access() will be removed.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

nvdimm: make CONFIG_NVDIMM_DAX 'bool'

A bugfix just tried to address a randconfig build problem and introduced
a variant of the same problem: with CONFIG_LIBNVDIMM=y and
CONFIG_NVDIMM_DAX=m, the nvdimm module now fails to link:

drivers/nvdimm/built-in.o: In function `to_nd_device_type':
bus.c:(.text+0x1b5d): undefined reference to `is_nd_dax'
drivers/nvdimm/built-in.o: In function `nd_region_notify_driver_action.constprop.2':
region_devs.c:(.text+0x6b6c): undefined reference to `is_nd_dax'
region_devs.c:(.text+0x6b8c): undefined reference to `to_nd_dax'
drivers/nvdimm/built-in.o: In function `nd_region_probe':
region.c:(.text+0x70f3): undefined reference to `nd_dax_create'
drivers/nvdimm/built-in.o: In function `mode_show':
namespace_devs.c:(.text+0xa196): undefined reference to `is_nd_dax'
drivers/nvdimm/built-in.o: In function `nvdimm_namespace_common_probe':
(.text+0xa55f): undefined reference to `is_nd_dax'
drivers/nvdimm/built-in.o: In function `nvdimm_namespace_common_probe':
(.text+0xa56e): undefined reference to `to_nd_dax'

This reverts the earlier fix, making NVDIMM_DAX a 'bool' option again
as it should be (it gets linked into the libnvdimm module). To fix
the original problem, I'm adding a dependency on LIBNVDIMM to
DEV_DAX_PMEM, which ensures we can't have that one built-in if the
rest is a module.

Fixes: 4e65e9381c7a ("/dev/dax: fix Kconfig dependency build breakage")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

docs: fix locations of several documents that got moved

The previous patch renamed several files that are cross-referenced
along the Kernel documentation. Adjust the links to point to
the right places.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

/dev/dax: fix Kconfig dependency build breakage

The function dax_pmem_probe() in drivers/dax/pmem.c is compiled under the
CONFIG_DEV_DAX_PMEM tri-state config option. This config option currently
only depends on CONFIG_NVDIMM_DAX, a bool, which means that the following
configuration is possible:

CONFIG_LIBNVDIMM=m
...
CONFIG_NVDIMM_DAX=y
CONFIG_DEV_DAX=y
CONFIG_DEV_DAX_PMEM=y

With this config LIBNVDIMM is compiled as a module with NVDIMM_DAX=y just
meaning that we will compile drivers/nvdimm/dax_devs.c into that module.
However, dax_pmem_probe() depends on several symbols defined in
drivers/nvdimm/dax_devs.c, which results in the following build errors:

drivers/built-in.o: In function `dax_pmem_probe':
linux/drivers/dax/pmem.c:70: undefined reference to `to_nd_dax'
linux/drivers/dax/pmem.c:74: undefined reference to
`nvdimm_namespace_common_probe'
linux/drivers/dax/pmem.c:80: undefined reference to `devm_nsio_enable'
linux/drivers/dax/pmem.c:81: undefined reference to `nvdimm_setup_pfn'
linux/drivers/dax/pmem.c:84: undefined reference to `devm_nsio_disable'
linux/drivers/dax/pmem.c:122: undefined reference to `to_nd_region'
drivers/built-in.o: In function `dax_pmem_init':
linux/drivers/dax/pmem.c:147: undefined reference to `__nd_driver_register'

Fix this by making NVDIMM_DAX a tristate. DEV_DAX_PMEM depends on
NVDIMM_DAX which depends on LIBNVDIMM. Since they are all now tristates,
if LIBNVDIMM is built as a kernel module DEV_DAX_PMEM will be as well.
This prevents dax_devs.c from being built as a built-in while its
dependencies are in the libnvdimm.ko module.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

libnvdimm: introduce devm_nvdimm_memremap(), convert nfit_spa_map() users

In preparation for generically mapping flush hint addresses for both the
BLK and PMEM use case, provide a generic / reference counted mapping
api. Given the fact that a dimm may belong to multiple regions (PMEM
and BLK), the flush hint addresses need to be held valid as long as any
region associated with the dimm is active. This is similar to the
existing BLK-region case where multiple BLK-regions may share an
aperture mapping. Up-level this shared / reference-counted mapping
capability from the nfit driver to a core nvdimm capability.

This eliminates the need for the nd_blk_region.disable() callback. Note
that the removal of nfit_spa_map() and related infrastructure is
deferred to a later patch.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

libnvdimm, dax: introduce device-dax infrastructure

Device DAX is the device-centric analogue of Filesystem DAX
(CONFIG_FS_DAX). It allows persistent memory ranges to be allocated and
mapped without need of an intervening file system. This initial
infrastructure arranges for a libnvdimm pfn-device to be represented as
a different device-type so that it can be attached to a driver other
than the pmem driver.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

libnvdimm, pmem: 'struct page' for pmem

Enable the pmem driver to handle PFN device instances. Attaching a pmem
namespace to a pfn device triggers the driver to allocate and initialize
struct page entries for pmem. Memory capacity for this allocation comes
exclusively from RAM for now which is suitable for low PMEM to RAM
ratios. This mechanism will be expanded later for setting an "allocate
from PMEM" policy.

Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

libnvdimm, pfn: 'struct page' provider infrastructure

Implement the base infrastructure for libnvdimm PFN devices. Similar to
BTT devices they take a namespace as a backing device and layer
functionality on top. In this case the functionality is reserving space
for an array of 'struct page' entries to be handed out through
pfn_to_page(). For now this is just the basic libnvdimm-device-model for
configuring the base PFN device.

As the namespace claiming mechanism for PFN devices is mostly identical
to BTT devices drivers/nvdimm/claim.c is created to house the common
bits.

Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

libnvdimm, nfit, nd_blk: driver for BLK-mode access persistent memory

The libnvdimm implementation handles allocating dimm address space (DPA)
between PMEM and BLK mode interfaces. After DPA has been allocated from
a BLK-region to a BLK-namespace the nd_blk driver attaches to handle I/O
as a struct bio based block device. Unlike PMEM, BLK is required to
handle platform specific details like mmio register formats and memory
controller interleave. For this reason the libnvdimm generic nd_blk
driver calls back into the bus provider to carry out the I/O.

This initial implementation handles the BLK interface defined by the
ACPI 6 NFIT [1] and the NVDIMM DSM Interface Example [2] composed from
DCR (dimm control region), BDW (block data window), IDT (interleave
descriptor) NFIT structures and the hardware register format.
[1]: http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf
[2]: http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

nd_btt: atomic sector updates

BTT stands for Block Translation Table, and is a way to provide power
fail sector atomicity semantics for block devices that have the ability
to perform byte granularity IO. It relies on the capability of libnvdimm
namespace devices to do byte aligned IO.

The BTT works as a stacked blocked device, and reserves a chunk of space
from the backing device for its accounting metadata. It is a bio-based
driver because all IO is done synchronously, and there is no queuing or
asynchronous completions at either the device or the driver level.

The BTT uses 'lanes' to index into various 'on-disk' data structures,
and lanes also act as a synchronization mechanism in case there are more
CPUs than available lanes. We did a comparison between two lane lock
strategies - first where we kept an atomic counter around that tracked
which was the last lane that was used, and 'our' lane was determined by
atomically incrementing that. That way, for the nr_cpus > nr_lanes case,
theoretically, no CPU would be blocked waiting for a lane. The other
strategy was to use the cpu number we're scheduled on to and hash it to
a lane number. Theoretically, this could block an IO that could've
otherwise run using a different, free lane. But some fio workloads
showed that the direct cpu -> lane hash performed faster than tracking
'last lane' - my reasoning is the cache thrash caused by moving the
atomic variable made that approach slower than simply waiting out the
in-progress IO. This supports the conclusion that the driver can be a
very simple bio-based one that does synchronous IOs instead of queuing.

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Neil Brown <neilb@suse.de>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
[jmoyer: fix nmi watchdog timeout in btt_map_init]
[jmoyer: move btt initialization to module load path]
[jmoyer: fix memory leak in the btt initialization path]
[jmoyer: Don't overwrite corrupted arenas]
Signed-off-by: Vishal Verma <vishal.l.verma@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

libnvdimm: infrastructure for btt devices

NVDIMM namespaces, in addition to accepting "struct bio" based requests,
also have the capability to perform byte-aligned accesses. By default
only the bio/block interface is used. However, if another driver can
make effective use of the byte-aligned capability it can claim namespace
interface and use the byte-aligned ->rw_bytes() interface.

The BTT driver is the initial first consumer of this mechanism to allow
adding atomic sector update semantics to a pmem or blk namespace. This
patch is the sysfs infrastructure to allow configuring a BTT instance
for a namespace. Enabling that BTT and performing i/o is in a
subsequent patch.

Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

libnvdimm, pmem: move pmem to drivers/nvdimm/

Prepare the pmem driver to consume PMEM namespaces emitted by regions of
an nvdimm_bus instance. No functional change.

Acked-by: Christoph Hellwig <hch@lst.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

libnvdimm, nfit: initial libnvdimm infrastructure and NFIT support

A struct nvdimm_bus is the anchor device for registering nvdimm
resources and interfaces, for example, a character control device,
nvdimm devices, and I/O region devices. The ACPI NFIT (NVDIMM Firmware
Interface Table) is one possible platform description for such
non-volatile memory resources in a system. The nfit.ko driver attaches
to the "ACPI0012" device that indicates the presence of the NFIT and
parses the table to register a struct nvdimm_bus instance.

Cc: <linux-acpi@vger.kernel.org>
Cc: Lv Zheng <lv.zheng@intel.com>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>