A recent flurry of bug discoveries in the nfit driver's DSM marshalling
routine has highlighted the fact that we do not have unit test coverage
for this routine. Add a self-test of acpi_nfit_ctl() routine before
probing the "nfit_test.0" device. This mocks stimulus to acpi_nfit_ctl()
and if any of the tests fail "nfit_test.0" will be unavailable causing
the rest of the tests to not run / fail.

This unit test will also be a place to land reproductions of quirky BIOS
behavior discovered in the field and ensure the kernel does not regress
against implementations it has seen in practice.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Given dimms and bus commands share the same command number space we need
to be careful that we are translating status in the correct context.
Otherwise we can, for example, fail an ND_CMD_GET_CONFIG_SIZE command
because max_xfer is zero. It fails because that condition erroneously
correlates with the 'cleared == 0' failure of ND_CMD_CLEAR_ERROR.

Cc: <stable@vger.kernel.org>
Fixes: aef25338 ("libnvdimm, nfit: centralize command status translation")
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

If an ARS Status command returns truncated output, do not process
partial records or otherwise consume non-status fields.

Cc: <stable@vger.kernel.org>
Fixes: 0caeef63 ("libnvdimm: Add a poison list and export badblocks")
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Given ambiguities in the ACPI 6.1 definition of the "Output (Size)"
field of the ARS (Address Range Scrub) Status command, a firmware
implementation may in practice return 0, 4, or 8 to indicate that there
is no output payload to process.

The specification states "Size of Output Buffer in bytes, including this
field.". However, 'Output Buffer' is also the name of the entire
payload, and earlier in the specification it states "Max Query ARS
Status Output Buffer Size: Maximum size of buffer (including the Status
and Extended Status fields)".

Without this fix if the BIOS happens to return 0 it causes memory
corruption as evidenced by this result from the acpi_nfit_ctl() unit
test.

 ars_status00000000: 00020000 00000000                    ........
 BUG: stack guard page was hit at ffffc90001750000 (stack is ffffc9000174c000..ffffc9000174ffff)
 kernel stack overflow (page fault): 0000 [#1] SMP DEBUG_PAGEALLOC
 task: ffff8803332d2ec0 task.stack: ffffc9000174c000
 RIP: 0010:[<ffffffff814cfe72>]  [<ffffffff814cfe72>] __memcpy+0x12/0x20
 RSP: 0018:ffffc9000174f9a8  EFLAGS: 00010246
 RAX: ffffc9000174fab8 RBX: 0000000000000000 RCX: 000000001fffff56
 RDX: 0000000000000000 RSI: ffff8803231f5a08 RDI: ffffc90001750000
 RBP: ffffc9000174fa88 R08: ffffc9000174fab0 R09: ffff8803231f54b8
 R10: 0000000000000008 R11: 0000000000000001 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000003 R15: ffff8803231f54a0
 FS:  00007f3a611af640(0000) GS:ffff88033ed00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: ffffc90001750000 CR3: 0000000325b20000 CR4: 00000000000406e0
 Stack:
  ffffffffa00bc60d 0000000000000008 ffffc90000000001 ffffc9000174faac
  0000000000000292 ffffffffa00c24e4 ffffffffa00c2914 0000000000000000
  0000000000000000 ffffffff00000003 ffff880331ae8ad0 0000000800000246
 Call Trace:
  [<ffffffffa00bc60d>] ? acpi_nfit_ctl+0x49d/0x750 [nfit]
  [<ffffffffa01f4fe0>] nfit_test_probe+0x670/0xb1b [nfit_test]

Cc: <stable@vger.kernel.org>
Fixes: 747ffe11 ("libnvdimm, tools/testing/nvdimm: fix 'ars_status' output buffer sizing")
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

ACPI DSMs can have an 'extended' status which can be non-zero to convey
additional information about the command. In the xlat_status routine,
where we translate the command statuses, we were returning an error for
a non-zero extended status, even if the primary status indicated success.

Return from each command's 'case' once we have verified both its status
and extend status are good.

Cc: <stable@vger.kernel.org>
Fixes: 11294d63 ("nfit: fail DSMs that return non-zero status by default")
Signed-off-by: NVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Before we add more libnvdimm-private fields to nd_mapping make it clear
which parameters are input vs libnvdimm internals. Use struct
nd_mapping_desc instead of struct nd_mapping in nd_region_desc and make
struct nd_mapping private to libnvdimm.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Starting a full Address Range Scrub (ARS) on hitting a memory error
machine check exception may not always be desirable. Provide a way
through sysfs to toggle the behavior between just adding the address
(cache line) where the MCE happened to the poison list and doing a full
scrub. The former (selective insertion of the address) is done
unconditionally.

Cc: linux-acpi@vger.kernel.org
Cc: Linda Knippers <linda.knippers@hpe.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

For the DSMs where the kernel knows the format of the output buffer and
originates those DSMs from within the kernel, return -EIO for any
non-zero status.  If the BIOS is indicating a status that we do not know
how to handle, fail the DSM.

Cc: <stable@vger.kernel.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Trigger an nmemX/nfit/flags attribute to fire an event whenever a
smart-threshold DSM is received.
Reviewed-by: NVishal Verma <vishal.l.verma@intel.com>
Acked-by: NRafael J. Wysocki <rafael@kernel.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Per "ACPI 6.1 Section 9.20.3" NVDIMM devices, children of the ACPI0012
NVDIMM Root device, can receive health event notifications.

Given that these devices are precluded from registering a notification
handler via acpi_driver.acpi_device_ops (due to no _HID), we use
acpi_install_notify_handler() directly.  The registered handler,
acpi_nvdimm_notify(), triggers a poll(2) event on the nmemX/nfit/flags
sysfs attribute when a health event notification is received.

Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NToshi Kani <toshi.kani@hpe.com>
Reviewed-by: NVishal Verma <vishal.l.verma@intel.com>
Acked-by: NRafael J. Wysocki <rafael@kernel.org>
Reviewed-by: NToshi Kani <toshi.kani@hpe.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

We have had a couple bugs in this implementation in the past and before
we add another ->notify() implementation for nvdimm devices, lets allow
this routine to be exercised via nfit_test.

Rewrite acpi_nfit_notify() in terms of a generic struct device and
acpi_handle parameter, and then implement a mock acpi_evaluate_object()
that returns a _FIT payload.

Cc: Vishal Verma <vishal.l.verma@intel.com>
Reviewed-by: NVishal Verma <vishal.l.verma@intel.com>
Acked-by: NRafael J. Wysocki <rafael@kernel.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Commit 20985164 "acpi: nfit: Add support for hot-add" added
support for _FIT notifications, but it neglected to verify the
notification event code matches the one in the ACPI spec for
"NFIT Update". Currently there is only one code in the spec, but
once additional codes are added, older kernels (without this fix)
will misbehave by assuming all event notifications are for an
NFIT Update.

Fixes: 20985164 ("acpi: nfit: Add support for hot-add")
Cc: <stable@vger.kernel.org>
Cc: <linux-acpi@vger.kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Reported-by: NLinda Knippers <linda.knippers@hpe.com>
Signed-off-by: NVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The "NVDIMM Block Window Driver Writer's Guide":

    http://pmem.io/documents/NVDIMM_DriverWritersGuide-July-2016.pdf

...defines the layout of the block window status register.  For the July
2016 version of the spec linked to above, this happens in Figure 4 on
page 26.

The only bits defined in this spec are bits 31, 5, 4, 2, 1 and 0.  The
rest of the bits in the status register are reserved, and there is a
warning following the diagram that says:

    Note: The driver cannot assume the value of the RESERVED bits in the
    status register are zero. These reserved bits need to be masked off, and
    the driver must avoid checking the state of those bits.

This change ensures that for hardware implementations that set these
reserved bits in the status register, the driver won't incorrectly fail the
block I/Os.

Cc: <stable@vger.kernel.org> #v4.2+
Reviewed-by: NLee, Chun-Yi <jlee@suse.com>
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

When a latent (unknown to 'badblocks') error is encountered, it will
trigger a machine check exception. On a system with machine check
recovery, this will only SIGBUS the process(es) which had the bad page
mapped (as opposed to a kernel panic on platforms without machine
check recovery features). In the former case, we want to trigger a full
rescan of that nvdimm bus. This will allow any additional, new errors
to be captured in the block devices' badblocks lists, and offending
operations on them can be trapped early, avoiding machine checks.

This is done by registering a callback function with the
x86_mce_decoder_chain and calling the new ars_rescan functionality with
the address in the mce notificatiion.

Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: NVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

With the arrival of x86-machine-check support the nfit driver will add a
(conditionally-compiled) source file.  Prepare for this by moving all
nfit source to drivers/acpi/nfit/.  This is pure code movement, no
functional changes.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Normally, an ARS (Address Range Scrub) only happens at
boot/initialization time. There can however arise situations where a
bus-wide rescan is needed - notably, in the case of discovering a latent
media error, we should do a full rescan to figure out what other sectors
are bad, and thus potentially avoid triggering an mce on them in the
future. Also provide a sysfs trigger to start a bus-wide scrub.

Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

While testing the new on-demand ARS patches we discovered that
differences between the nfit_test and normal nfit driver shutdown paths
can leak resources.  Unify the shutdown paths to trigger via a devm_
callback when the acpi_desc->dev is unbound from its driver.
Reviewed-by: NLee, Chun-Yi <jlee@suse.com>
Reported-by: NVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Let the provider module be explicitly passed in rather than implicitly
assumed by the module that calls nvdimm_bus_register().  This is in
preparation for unifying the nfit and nfit_test driver teardown paths.
Reviewed-by: NLee, Chun-Yi <jlee@suse.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Pass the nfit buffer as a parameter rather than hanging it off of
acpi_desc.
Reviewed-by: N"Lee, Chun-Yi" <jlee@suse.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

acpi_evaluate_object() allocates memory. Free the buffer allocated
during acpi_nfit_add(). In order for this memory to be freed
acpi_nfit_init() needs to be converted to duplicate the nfit contents in
its internal allocation.  Use zero-length arrays to minimize the thrash
with the rest of the nfit driver implementation.

All of the add_<nfit-sub-table>() routines now validate a minimum table
size and expect hotplugged tables to match the size of the original
table to count as a duplicate. For variable length tables, like 'idt'
and 'flush', we calculate the dynamic size. Note that hotplug by
definition cannot change the interleave as it would cause data
corruption of in-use namespaces.

Cc: Vishal Verma <vishal.l.verma@intel.com>
Reported-by: NXiao Guangrong <guangrong.xiao@intel.com>
Reported-by: NHaozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This patch adds logic to treat virtual ramdisk SPA as pmem region, then
ramdisk's /dev/pmem* device can be mounted with iso9660.

It's useful to work with the httpboot in EFI firmware to pull a remote
ISO file to the local memory region for booting and installation.

Wiki page of UEFI HTTPBoot with OVMF:
	https://en.opensuse.org/UEFI_HTTPBoot_with_OVMF

The ramdisk function in EDK2/OVMF generates a ACPI0012 root device that
it contains empty _STA but without _DSM:

DefinitionBlock ("ssdt2.aml", "SSDT", 2, "INTEL ", "RamDisk ", 0x00001000)
{
    Scope (\_SB)
    {
        Device (NVDR)
        {
            Name (_HID, "ACPI0012")  // _HID: Hardware ID
            Name (_STR, Unicode ("NVDIMM Root Device"))  // _STR: Description String
            Method (_STA, 0, NotSerialized)  // _STA: Status
            {
                Return (0x0F)
            }
        }
    }
}

In section 5.2.25.2 of ACPI 6.1 spec, it mentions that the "SPA Range
Structure Index" of virtual SPA shall be set to zero. That means virtual SPA
will not be associated by any NVDIMM region mapping.

The VCD's SPA Range Structure in NFIT is similar to virtual disk region
as following:

[028h 0040   2]                Subtable Type : 0000 [System Physical Address Range]
[02Ah 0042   2]                       Length : 0038

[02Ch 0044   2]                  Range Index : 0000
[02Eh 0046   2]        Flags (decoded below) : 0000
                   Add/Online Operation Only : 0
                      Proximity Domain Valid : 0
[030h 0048   4]                     Reserved : 00000000
[034h 0052   4]             Proximity Domain : 00000000
[038h 0056  16]           Address Range GUID : 77AB535A-45FC-624B-5560-F7B281D1F96E
[048h 0072   8]           Address Range Base : 00000000B6ABD018
[050h 0080   8]         Address Range Length : 0000000005500000
[058h 0088   8]         Memory Map Attribute : 0000000000000000

The way to not associate a SPA range is to never reference it from a "flush hint",
"interleave", or "control region" table.

After testing on OVMF, pmem driver can support the region that it doesn't
assoicate to any NVDIMM mapping. So, treat VCD like pmem is a idea to get
a pmem block device that it contains iso.

v4:
Instoduce nfit_spa_is_virtual() to check virtual ramdisk SPA and create
pmem region.

v3:
To simplify patch, removed useless VCD region in libnvdimm.

v2:
Removed the code for setting VCD to a read-only region.

Cc: Gary Lin <GLin@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Linda Knippers <linda.knippers@hpe.com>
Signed-off-by: NLee, Chun-Yi <jlee@suse.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Commit 4995734e "acpi, nfit: fix acpi_check_dsm() vs zero functions
implemented" attempted to fix a QEMU regression by supporting its usage
of a zero-mask as a valid response to a DSM-family probe request.
However, this behavior breaks HP platforms that return a zero-mask by
default causing the probe to misidentify the DSM-family.

Instead, the QEMU regression can be fixed by simply not requiring the DSM
family to be identified.

This effectively reverts commit 4995734e, and removes the DSM
requirement from the init path.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Cc: Linda Knippers <linda.knippers@hpe.com>
Fixes: 4995734e ("acpi, nfit: fix acpi_check_dsm() vs zero functions implemented")
Reported-by: NJerry Hoemann <jerry.hoemann@hpe.com>
Tested-by: NJerry Hoemann <jerry.hoemann@hpe.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

nvdimm_flush() is a replacement for the x86 'pcommit' instruction.  It is
an optional write flushing mechanism that an nvdimm bus can provide for
the pmem driver to consume.  In the case of the NFIT nvdimm-bus-provider
nvdimm_flush() is implemented as a series of flush-hint-address [1]
writes to each dimm in the interleave set (region) that backs the
namespace.

The nvdimm_has_flush() routine relies on platform firmware to describe
the flushing capabilities of a platform.  It uses the heuristic of
whether an nvdimm bus provider provides flush address data to return a
ternary result:

      1: flush addresses defined
      0: dimm topology described without flush addresses (assume ADR)
 -errno: no topology information, unable to determine flush mechanism

The pmem driver is expected to take the following actions on this ternary
result:

      1: nvdimm_flush() in response to REQ_FUA / REQ_FLUSH and shutdown
      0: do not set, WC or FUA on the queue, take no further action
 -errno: warn and then operate as if nvdimm_has_flush() returned '0'

The caveat of this heuristic is that it can not distinguish the "dimm
does not have flush address" case from the "platform firmware is broken
and failed to describe a flush address".  Given we are already
explicitly trusting the NFIT there's not much more we can do beyond
blacklisting broken firmwares if they are ever encountered.

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

In preparation for triggering flushes of a DIMM's writes-posted-queue
(WPQ) via the pmem driver move mapping of flush hint addresses to the
region driver.  Since this uses devm_nvdimm_memremap() the flush
addresses will remain mapped while any region to which the dimm belongs
is active.

We need to communicate more information to the nvdimm core to facilitate
this mapping, namely each dimm object now carries an array of flush hint
address resources.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Now that all shared mappings are handled by devm_nvdimm_memremap() we no
longer need nfit_spa_map() nor do we need to trigger a callback to the
bus provider at region disable time.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

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: NDan Williams <dan.j.williams@intel.com>

We were needlessly converting nfit_mem_init() errors to -ENOMEM.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Before enabling use of flush hints for pmem regions, we need to make
sure they are always associated.  Move the initialization of nfit_flush
out of the block-window specific init path to the general init path.

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

If devm_add_action() fails, we are explicitly calling the cleanup to free
the resources allocated. Lets use the helper devm_add_action_or_reset()
and return directly in case of error, since the cleanup function
has been already called by the helper if there was any error.
Signed-off-by: NVikas C Sajjan <vikas.cha.sajjan@hpe.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NLee, Chun-Yi <jlee@suse.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Per JEDEC Annex L Release 3 the SPD data is:

Bits 9~5 00 000 = Function Undefined
         00 001 = Byte addressable energy backed
         00 010 = Block addressed
         00 011 = Byte addressable, no energy backed
         All other codes reserved
Bits 4~0 0 0000 = Proprietary interface
         0 0001 = Standard interface 1
         All other codes reserved; see Definitions of Functions

...and per the ACPI 6.1 spec:

    byte0: Bits 4~0 (0 or 1)
    byte1: Bits 9~5 (1, 2, or 3)

...so a format interface code displayed as 0x301 should be stored in the
nfit as (0x1, 0x3), little-endian.

Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Robert Elliott <elliott@hpe.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=121161
Fixes: 30ec5fd4 ("nfit: fix format interface code byte order per ACPI6.1")
Fixes: 5ad9a7fd ("acpi/nfit: Update nfit driver to comply with ACPI 6.1")
Reported-by: NKristin Jacque <kristin.jacque@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

QEMU 2.6 implements nascent support for nvdimm DSMs. Depending on
configuration it may only implement the function0 dsm to indicate that
no other DSMs are available. Commit 31eca76b "nfit, libnvdimm:
limited/whitelisted dimm command marshaling mechanism" breaks QEMU, but
QEMU is spec compliant.  Per the spec the way to indicate that no
functions are supported is:

    If Function Index is zero, the return is a buffer containing one bit
    for each function index, starting with zero. Bit 0 indicates whether
    there is support for any functions other than function 0 for the
    specified UUID and Revision ID. If set to zero, no functions are
    supported (other than function zero) for the specified UUID and
    Revision ID.

Update the nfit driver to determine the family (interface UUID) without
requiring the implementation to define any other functions, i.e.
short-circuit acpi_check_dsm() to succeed per the spec.  The nfit driver
appears to be the only user passing funcs==0 to acpi_check_dsm(), so
this behavior change of the common routine should be limited to the
probing done by the nfit driver.

Cc: Len Brown <lenb@kernel.org>
Cc: Jerry Hoemann <jerry.hoemann@hpe.com>
Acked-by: N"Rafael J. Wysocki" <rafael@kernel.org>
Fixes: 31eca76b ("nfit, libnvdimm: limited/whitelisted dimm command marshaling mechanism")
Reported-by: NXiao Guangrong <guangrong.xiao@linux.intel.com>
Tested-by: NXiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Add the Microsoft _DSM command set to the white list of NVDIMM command
sets.

This command set is documented at:

    https://msdn.microsoft.com/library/windows/hardware/mt604741

Cc: Pavel Machek <pavel@ucw.cz>
[pavel: fix up braces]
Signed-off-by: NStuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Communicate the command format and supported functions to userspace
tooling.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Module option to limit userspace to the publicly defined command set.
For cases where private DIMM commands may be interfering with the
kernel's handling of DIMM state this option can be set to block vendor
specific commands.

Cc: Jerry Hoemann <jerry.hoemann@hpe.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

When transportation of the command completes successfully, it indicates
that the 'status' result is valid.  Fix the missed checking and
translation of the status field at the end of acpi_nfit_ctl().
Otherwise, we fail to handle reported errors and assume commands
complete successfully.
Reported-by: NLinda Knippers <linda.knippers@hpe.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Similar to pci-sysfs export the subsystem information available in the
NFIT.  ACPI 6.1 clarifies that this data is copied as an array of bytes
from the DIMM SPD data.
Reported-by: NRyon Jensen <ryon.jensen@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

There are currently 4 known similar but incompatible definitions of the
command sets that can be sent to an NVDIMM through ACPI.  It is also
clear that future platform generations (ACPI or not) will continue to
revise and extend the DIMM command set as new devices and use cases
arrive.

It is obviously untenable to continue to proliferate divergence
of these command definitions, and to that end a standardization process
has begun to provide for a unified specification.  However, that leaves a
problem about what to do with this first generation where vendors are
already shipping divergence.

The Linux kernel can support these initial diverged platforms without
giving platform-firmware free reign to continue to diverge and compound
kernel maintenance overhead.  The kernel implementation can encourage
standardization in two ways:

1/ Require that any function code that userspace wants to send be
   explicitly white-listed in the implementation.  For ACPI this means
   function codes marked as supported by acpi_check_dsm() may
   only be invoked if they appear in the white-list.  A function must be
   publicly documented before it is added to the white-list.

2/ The above restrictions can be trivially bypassed by using the
   "vendor-specific" payload command.  However, since vendor-specific
   commands are by definition not publicly documented and have the
   potential to corrupt the kernel's view of the dimm state, we provide a
   toggle to disable vendor-specific operations.  Enabling undefined
   behavior is a policy decision that can be made by the platform owner
   and encourages firmware implementations to choose public over
   private command implementations.

Based on an initial patch from Jerry Hoemann
Cc: Jerry Hoemann <jerry.hoemann@hpe.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Clarify the distinction between "commands", the ioctls userspace calls
to request the kernel take some action on a given dimm device, and
"_DSMs", the actual function numbers used in the firmware interface to
the DIMM.  _DSMs are ACPI specific whereas commands are Linux kernel
generic.

This is in preparation for breaking the 1:1 implicit relationship
between the kernel ioctl number space and the firmware specific function
numbers.

Cc: Jerry Hoemann <jerry.hoemann@hpe.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

ACPI 6.1, section 5.2.25.9, defines an identifier for an NVDIMM.

Change the NFIT driver to add a new sysfs file "id" under nfit
directory.
Signed-off-by: NToshi Kani <toshi.kani@hpe.com>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Robert Elliott <elliott@hpe.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

ACPI 6.1, Table 5-133, updates NVDIMM Control Region Structure
as follows.
 - Valid Fields, Manufacturing Location, and Manufacturing Date
   are added from reserved range.  No change in the structure size.
 - IDs (SPD values) are stored as arrays of bytes (i.e. big-endian
   format).  The spec clarifies that they need to be represented
   as arrays of bytes as well.

This patch makes the following changes to support this update.
 - Change the NFIT driver to show SPD ID values in big-endian
   format.
 - Change sprintf format to use "0x" instead of "#" since "%#02x"
   does not prepend '0'.

link: http://www.uefi.org/sites/default/files/resources/ACPI_6_1.pdfSigned-off-by: NToshi Kani <toshi.kani@hpe.com>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Robert Elliott <elliott@hpe.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>