Based on an original patch by Ross Zwisler [1].

Writes to persistent memory have the potential to be posted to cpu
cache, cpu write buffers, and platform write buffers (memory controller)
before being committed to persistent media.  Provide apis,
memcpy_to_pmem(), wmb_pmem(), and memremap_pmem(), to write data to
pmem and assert that it is durable in PMEM (a persistent linear address
range).  A '__pmem' attribute is added so sparse can track proper usage
of pointers to pmem.

This continues the status quo of pmem being x86 only for 4.2, but
reworks to ioremap, and wider implementation of memremap() will enable
other archs in 4.3.

[1]: https://lists.01.org/pipermail/linux-nvdimm/2015-May/000932.html

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
[djbw: various reworks]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Add support of sysfs 'numa_node' to I/O-related NVDIMM devices
under /sys/bus/nd/devices, regionN, namespaceN.0, and bttN.x.

An example of numa_node values on a 2-socket system with a single
NVDIMM range on each socket is shown below.
  /sys/bus/nd/devices
  |-- btt0.0/numa_node:0
  |-- btt1.0/numa_node:1
  |-- btt1.1/numa_node:1
  |-- namespace0.0/numa_node:0
  |-- namespace1.0/numa_node:1
  |-- region0/numa_node:0
  |-- region1/numa_node:1

These numa_node files are then linked under the block class of
their device names.
  /sys/class/block/pmem0/device/numa_node:0
  /sys/class/block/pmem1s/device/numa_node:1

This enables numactl(8) to accept 'block:' and 'file:' paths of
pmem and btt devices as shown in the examples below.
  numactl --preferred block:pmem0 --show
  numactl --preferred file:/dev/pmem1s --show
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

ACPI NFIT table has System Physical Address Range Structure entries that
describe a proximity ID of each range when ACPI_NFIT_PROXIMITY_VALID is
set in the flags.

Change acpi_nfit_register_region() to map a proximity ID to its node ID,
and set it to a new numa_node field of nd_region_desc, which is then
conveyed to the nd_region device.

The device core arranges for btt and namespace devices to inherit their
node from their parent region.
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
[djbw: move set_dev_node() from region.c to bus.c]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

The kernel initializes CPU & memory's NUMA topology from ACPI
SRAT table.  Some other ACPI tables, such as NFIT and DMAR, also
contain proximity IDs for their device's NUMA topology.  This
information can be used to improve performance of these devices.

This patch introduces acpi_map_pxm_to_online_node(), which is
similar to acpi_map_pxm_to_node(), but always returns an online
node.  When the mapped node from a given proximity ID is offline,
it looks up the node distance table and returns the nearest
online node.

ACPI device drivers, which are called after the NUMA initialization
has completed in the kernel, can call this interface to obtain their
device NUMA topology from ACPI tables.  Such drivers do not have to
deal with offline nodes.  A node may be offline when a device
proximity ID is unique, SRAT memory entry does not exist, or NUMA is
disabled, ex. "numa=off" on x86.

This patch also moves the pxm range check from acpi_get_node() to
acpi_map_pxm_to_node().
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com&gt;>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Upon detection of an unarmed dimm in a region, arrange for descendant
BTT, PMEM, or BLK instances to be read-only.  A dimm is primarily marked
"unarmed" via flags passed by platform firmware (NFIT).

The flags in the NFIT memory device sub-structure indicate the state of
the data on the nvdimm relative to its energy source or last "flush to
persistence".  For the most part there is nothing the driver can do but
advertise the state of these flags in sysfs and emit a message if
firmware indicates that the contents of the device may be corrupted.
However, for the case of ACPI_NFIT_MEM_ARMED, the driver can arrange for
the block devices incorporating that nvdimm to be marked read-only.
This is a safe default as the data is still available and new writes are
held off until the administrator either forces read-write mode, or the
energy source becomes armed.

A 'read_only' attribute is added to REGION devices to allow for
overriding the default read-only policy of all descendant block devices.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

...since they are effectively SSDs as far as userspace is concerned.
Reviewed-by: Vishal Verma <vishal.l.verma@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

This is disabled by default as the overhead is prohibitive, but if the
user takes the action to turn it on we'll oblige.
Reviewed-by: Vishal Verma <vishal.l.verma@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Various cleanups:

1/ Kill the BUG_ON since we've already told the block layer we don't
   support DISCARD on all these drivers.

2/ Kill the 'rw' variable, no need to cache it.

3/ Kill the local 'sector' variable.  bio_for_each_segment() is already
   advancing the iterator's sector number by the bio_vec length.

4/ Kill the check for accessing past the end of device
   generic_make_request_checks() already does that.
Suggested-by: Christoph Hellwig <hch@lst.de>
[hch: kill access past end of the device check]
Reviewed-by: Vishal Verma <vishal.l.verma@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

There is no hardware limit to enforce on the size of the i/o that can be passed
to an nvdimm block device, so set it to UINT_MAX.
Reviewed-by: Vishal Verma <vishal.l.verma@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Support multiple block sizes (sector + metadata) for nd_blk in the
same way as done for the BTT. Add the idea of an 'internal' lbasize,
which is properly aligned and padded, and store metadata in this space.
Signed-off-by: Vishal Verma <vishal.l.verma@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Support multiple block sizes (sector + metadata) using the blk integrity
framework. This registers a new integrity template that defines the
protection information tuple size based on the configured metadata size,
and simply acts as a passthrough for protection information generated by
another layer. The metadata is written to the storage as-is, and read back
with each sector.
Signed-off-by: Vishal Verma <vishal.l.verma@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

If a block device has bio integrity enabled, rw_page will bypass the
integrity payload, which is undesirable. Skip rw_page if this is the
case.

Currently brd and zram provide rw_page, and the proposed 'nd' drivers
will too.

Cc: Jens Axboe <axboe@fb.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Suggested-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Maintainer information and documentation for drivers/nvdimm

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: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

'libnvdimm' is the first driver sub-system in the kernel to implement
mocking for unit test coverage.  The nfit_test module gets built as an
external module and arranges for external module replacements of nfit,
libnvdimm, nd_pmem, and nd_blk.  These replacements use the linker
--wrap option to redirect calls to ioremap() + request_mem_region() to
custom defined unit test resources.  The end result is a fully
functional nvdimm_bus, as far as userspace is concerned, but with the
capability to perform otherwise destructive tests on emulated resources.

Q: Why not use QEMU for this emulation?
QEMU is not suitable for unit testing.  QEMU's role is to faithfully
emulate the platform.  A unit test's role is to unfaithfully implement
the platform with the goal of triggering bugs in the corners of the
sub-system implementation.  As bugs are discovered in platforms, or the
sub-system itself, the unit tests are extended to backstop a fix with a
reproducer unit test.

Another problem with QEMU is that it would require coordination of 3
software projects instead of 2 (kernel + libndctl [1]) to maintain and
execute the tests.  The chances for bit rot and the difficulty of
getting the tests running goes up non-linearly the more components
involved.


Q: Why submit this to the kernel tree instead of external modules in
   libndctl?
Simple, to alleviate the same risk that out-of-tree external modules
face.  Updates to drivers/nvdimm/ can be immediately evaluated to see if
they have any impact on tools/testing/nvdimm/.


Q: What are the negative implications of merging this?
It is a unique maintenance burden because the purpose of mocking an
interface to enable a unit test is to purposefully short circuit the
semantics of a routine to enable testing.  For example
__wrap_ioremap_cache() fakes the pmem driver into "ioremap()'ing" a test
resource buffer allocated by dma_alloc_coherent().  The future
maintenance burden hits when someone changes the semantics of
ioremap_cache() and wonders what the implications are for the unit test.

[1]: https://github.com/pmem/ndctl

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>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

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>

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>

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>

After 'uuid', 'size', 'sector_size', and optionally 'alt_name' have been
set to valid values the labels on the dimm can be updated.  The
difference with the pmem case is that blk namespaces are limited to one
dimm and can cover discontiguous ranges in dpa space.

Also, after allocating label slots, it is useful for userspace to know
how many slots are left.  Export this information in sysfs.

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

After 'uuid', 'size', and optionally 'alt_name' have been set to valid
values the labels on the dimms can be updated.

Write procedure is:
1/ Allocate and write new labels in the "next" index
2/ Free the old labels in the working copy
3/ Write the bitmap and the label space on the dimm
4/ Write the index to make the update valid

Label ranges directly mirror the dpa resource values for the given
label_id of the namespace.

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

A blk label set describes a namespace comprised of one or more
discontiguous dpa ranges on a single dimm.  They may alias with one or
more pmem interleave sets that include the given dimm.

This is the runtime/volatile configuration infrastructure for sysfs
manipulation of 'alt_name', 'uuid', 'size', and 'sector_size'.  A later
patch will make these settings persistent by writing back the label(s).

Unlike pmem namespaces, multiple blk namespaces can be created per
region.  Once a blk namespace has been created a new seed device
(unconfigured child of a parent blk region) is instantiated.  As long as
a region has 'available_size' != 0 new child namespaces may be created.

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

A complete label set is a PMEM-label per-dimm per-interleave-set where
all the UUIDs match and the interleave set cookie matches the hosting
interleave set.

Present sysfs attributes for manipulation of a PMEM-namespace's
'alt_name', 'uuid', and 'size' attributes.  A later patch will make
these settings persistent by writing back the label.

Note that PMEM allocations grow forwards from the start of an interleave
set (lowest dimm-physical-address (DPA)).  BLK-namespaces that alias
with a PMEM interleave set will grow allocations backward from the
highest DPA.

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

This on media label format [1] consists of two index blocks followed by
an array of labels.  None of these structures are ever updated in place.
A sequence number tracks the current active index and the next one to
write, while labels are written to free slots.

    +------------+
    |            |
    |  nsindex0  |
    |            |
    +------------+
    |            |
    |  nsindex1  |
    |            |
    +------------+
    |   label0   |
    +------------+
    |   label1   |
    +------------+
    |            |
     ....nslot...
    |            |
    +------------+
    |   labelN   |
    +------------+

After reading valid labels, store the dpa ranges they claim into
per-dimm resource trees.

[1]: http://pmem.io/documents/NVDIMM_Namespace_Spec.pdf

Cc: Neil Brown <neilb@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

On platforms that have firmware support for reading/writing per-dimm
label space, a portion of the dimm may be accessible via an interleave
set PMEM mapping in addition to the dimm's BLK (block-data-window
aperture(s)) interface.  A label, stored in a "configuration data
region" on the dimm, disambiguates which dimm addresses are accessed
through which exclusive interface.

Add infrastructure that allows the kernel to block modifications to a
label in the set while any member dimm is active.  Note that this is
meant only for enforcing "no modifications of active labels" via the
coarse ioctl command.  Adding/deleting namespaces from an active
interleave set is always possible via sysfs.

Another aspect of tracking interleave sets is tracking their integrity
when DIMMs in a set are physically re-ordered.  For this purpose we
generate an "interleave-set cookie" that can be recorded in a label and
validated against the current configuration.  It is the bus provider
implementation's responsibility to calculate the interleave set cookie
and attach it to a given region.

Cc: Neil Brown <neilb@suse.de>
Cc: <linux-acpi@vger.kernel.org>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

nd_pmem attaches to persistent memory regions and namespaces emitted by
the libnvdimm subsystem, and, same as the original pmem driver, presents
the system-physical-address range as a block device.

The existing e820-type-12 to pmem setup is converted to an nvdimm_bus
that emits an nd_namespace_io device.

Note that the X in 'pmemX' is now derived from the parent region.  This
provides some stability to the pmem devices names from boot-to-boot.
The minor numbers are also more predictable by passing 0 to
alloc_disk().

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

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>

The libnvdimm region driver is an intermediary driver that translates
non-volatile "region"s into "namespace" sub-devices that are surfaced by
persistent memory block-device drivers (PMEM and BLK).

ACPI 6 introduces the concept that a given nvdimm may simultaneously
offer multiple access modes to its media through direct PMEM load/store
access, or windowed BLK mode.  Existing nvdimms mostly implement a PMEM
interface, some offer a BLK-like mode, but never both as ACPI 6 defines.
If an nvdimm is single interfaced, then there is no need for dimm
metadata labels.  For these devices we can take the region boundaries
directly to create a child namespace device (nd_namespace_io).
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>

A "region" device represents the maximum capacity of a BLK range (mmio
block-data-window(s)), or a PMEM range (DAX-capable persistent memory or
volatile memory), without regard for aliasing.  Aliasing, in the
dimm-local address space (DPA), is resolved by metadata on a dimm to
designate which exclusive interface will access the aliased DPA ranges.
Support for the per-dimm metadata/label arrvies is in a subsequent
patch.

The name format of "region" devices is "regionN" where, like dimms, N is
a global ida index assigned at discovery time.  This id is not reliable
across reboots nor in the presence of hotplug.  Look to attributes of
the region or static id-data of the sub-namespace to generate a
persistent name.  However, if the platform configuration does not change
it is reasonable to expect the same region id to be assigned at the next
boot.

"region"s have 2 generic attributes "size", and "mapping"s where:
- size: the BLK accessible capacity or the span of the
  system physical address range in the case of PMEM.

- mappingN: a tuple describing a dimm's contribution to the region's
  capacity in the format (<nmemX>,<dpa>,<size>).  For a PMEM-region
  there will be at least one mapping per dimm in the interleave set.  For
  a BLK-region there is only "mapping0" listing the starting DPA of the
  BLK-region and the available DPA capacity of that space (matches "size"
  above).

The max number of mappings per "region" is hard coded per the
constraints of sysfs attribute groups.  That said the number of mappings
per region should never exceed the maximum number of possible dimms in
the system.  If the current number turns out to not be enough then the
"mappings" attribute clarifies how many there are supposed to be. "32
should be enough for anybody...".

Cc: Neil Brown <neilb@suse.de>
Cc: <linux-acpi@vger.kernel.org>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.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>

* Implement the device-model infrastructure for loading modules and
  attaching drivers to nvdimm devices.  This is a simple association of a
  nd-device-type number with a driver that has a bitmask of supported
  device types.  To facilitate userspace bind/unbind operations 'modalias'
  and 'devtype', that also appear in the uevent, are added as generic
  sysfs attributes for all nvdimm devices.  The reason for the device-type
  number is to support sub-types within a given parent devtype, be it a
  vendor-specific sub-type or otherwise.

* The first consumer of this infrastructure is the driver
  for dimm devices.  It simply uses control messages to retrieve and
  store the configuration-data image (label set) from each dimm.

Note: nd_device_register() arranges for asynchronous registration of
      nvdimm bus devices by default.

Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Neil Brown <neilb@suse.de>
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>

Most discovery/configuration of the nvdimm-subsystem is done via sysfs
attributes.  However, some nvdimm_bus instances, particularly the
ACPI.NFIT bus, define a small set of messages that can be passed to the
platform.  For convenience we derive the initial libnvdimm-ioctl command
formats directly from the NFIT DSM Interface Example formats.

    ND_CMD_SMART: media health and diagnostics
    ND_CMD_GET_CONFIG_SIZE: size of the label space
    ND_CMD_GET_CONFIG_DATA: read label space
    ND_CMD_SET_CONFIG_DATA: write label space
    ND_CMD_VENDOR: vendor-specific command passthrough
    ND_CMD_ARS_CAP: report address-range-scrubbing capabilities
    ND_CMD_ARS_START: initiate scrubbing
    ND_CMD_ARS_STATUS: report on scrubbing state
    ND_CMD_SMART_THRESHOLD: configure alarm thresholds for smart events

If a platform later defines different commands than this set it is
straightforward to extend support to those formats.

Most of the commands target a specific dimm.  However, the
address-range-scrubbing commands target the bus.  The 'commands'
attribute in sysfs of an nvdimm_bus, or nvdimm, enumerate the supported
commands for that object.

Cc: <linux-acpi@vger.kernel.org>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reported-by: Nicholas Moulin <nicholas.w.moulin@linux.intel.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Enable nvdimm devices to be registered on a nvdimm_bus.  The kernel
assigned device id for nvdimm devicesis dynamic.  If userspace needs a
more static identifier it should consult a provider-specific attribute.
In the case where NFIT is the provider, the 'nmemX/nfit/handle' or
'nmemX/nfit/serial' attributes may be used for this purpose.

Cc: Neil Brown <neilb@suse.de>
Cc: <linux-acpi@vger.kernel.org>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.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>

The control device for a nvdimm_bus is registered as an "nd" class
device.  The expectation is that there will usually only be one "nd" bus
registered under /sys/class/nd.  However, we allow for the possibility
of multiple buses and they will listed in discovery order as
ndctl0...ndctlN.  This character device hosts the ioctl for passing
control messages.  The initial command set has a 1:1 correlation with
the commands listed in the by the "NFIT DSM Example" document [1], but
this scheme is extensible to future command sets.

Note, nd_ioctl() and the backing ->ndctl() implementation are defined in
a subsequent patch.  This is simply the initial registrations and sysfs
attributes.

[1]: http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf

Cc: Neil Brown <neilb@suse.de>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: <linux-acpi@vger.kernel.org>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.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>

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>

ACPI 6.0 formalizes e820-type-7 and efi-type-14 as persistent memory.
Mark it "reserved" and allow it to be claimed by a persistent memory
device driver.

This definition is in addition to the Linux kernel's existing type-12
definition that was recently added in support of shipping platforms with
NVDIMM support that predate ACPI 6.0 (which now classifies type-12 as
OEM reserved).

Note, /proc/iomem can be consulted for differentiating legacy
"Persistent Memory (legacy)" E820_PRAM vs standard "Persistent Memory"
E820_PMEM.

Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
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>

ACPICA commit 60052949ba2aa7377106870da69b237193d10dc1

Error in transcription from the ACPI spec.

Link: https://github.com/acpica/acpica/commit/60052949Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPICA commit 83727bed8f715685a63a9f668e73c60496a06054

Add original UUIDs/GUIDs to the acuuid.h file.
Cleanup acpihelp output for UUIDs/GUIDs.

Link: https://github.com/acpica/acpica/commit/83727bedSigned-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPICA commit ed4de2e8b0a5dd6fc17773a055590bff0e995588

Version 20150515.

Link: https://github.com/acpica/acpica/commit/ed4de2e8Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPICA commit e4e17ca361373e9b81494bb4ca697a12cef3cba6

NVDIMM Firmware Interface Table.

Link: https://github.com/acpica/acpica/commit/e4e17ca3Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPICA commit d6d003556c6fc22e067d5d511577128a661266c3

-t option displays all ACPI tables.

Link: https://github.com/acpica/acpica/commit/d6d00355Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPICA commit 403b8b0023fd7549b2f9bf818fcc1ba481047b69

If non-AML files are used with the -e option, the disassembler
can fault. The fix is to ensure that all -e files are either
SSDTs or a DSDT. ACPICA BZ 1158.

Link: https://github.com/acpica/acpica/commit/403b8b00
Reference: https://bugs.acpica.org/show_bug.cgi?id=1158Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPICA commit b02b754a2b7afcd0384cb3b31f29eb1be028fe90

This patch adds support for DRTM (Dynamic Root of Trust for Measurement
table) in iasl. Lv Zheng.

Link: https://github.com/acpica/acpica/commit/b02b754aSigned-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>