The pcommit instruction is being deprecated in favor of either ADR
(asynchronous DRAM refresh: flush-on-power-fail) at the platform level, or
posted-write-queue flush addresses as defined by the ACPI 6.x NFIT (NVDIMM
Firmware Interface Table).

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: NIngo Molnar <mingo@redhat.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This reverts commit 8b3e34e4.

Given the deprecation of the pcommit instruction, the relevant VMX
features and CPUID bits are not going to be rolled into the SDM.  Remove
their usage from KVM.

Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ross Zwisler <ross.zwisler@linux.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>

New for ACPI 6.1, these fields are used in the common dimm
representation format defined by section 5.2.25.9 "NVDIMM representation
format".
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Test the virtual disk ranges that platform firmware like EDK2/OVMF might
emit.
Tested-by: N"Lee, Chun-Yi" <jlee@suse.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>

The __pmem address space was meant to annotate codepaths that touch
persistent memory and need to coordinate a call to wmb_pmem().  Now that
wmb_pmem() is gone, there is little need to keep this annotation.

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

All users have been replaced with flushing in the pmem driver.

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

nsio_rw_bytes() is used to write info block metadata to the namespace,
so it should trigger a flush after every write.  Replace wmb_pmem() with
nvdimm_flush() in this path.

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

Flushing posted-write queues is now deferred to REQ_FLUSH context, or
otherwise handled by an ADR event at the platform level.

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

Commit writes to media on system shutdown or pmem driver unload.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Given that nvdimm_flush() has higher overhead than wmb_pmem() (pointer
chasing through nd_region), and that we otherwise assume a platform has
ADR capability when flush hints are not present, move nvdimm_flush() to
REQ_FLUSH context.

Note that we still arrange for nvdimm_flush() to be called even in the
ADR case. We need at least once wmb() fence to push buffered writes in
the cpu out to the ADR protected domain.

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

When the NFIT provides multiple flush hint addresses per-dimm it is
expressing that the platform is capable of processing multiple flush
requests in parallel.  There is some fixed cost per flush request, let
the cost be shared in parallel on multiple cpus.

Since there may not be enough flush hint addresses for each cpu to have
one, keep a per-cpu index of the last used hint, hash it with current
pid, and assume that access pattern and scheduler randomness will keep
the flush-hint usage somewhat staggered across cpus.

Cc: Ross Zwisler <ross.zwisler@linux.intel.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>

nd_region device driver data will be used in the namespace i/o path.
Re-order nd_region_remove() to ensure this data stays live across
namespace device removal
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Sample nfit data to test the kernel's handling of the multiple
flush-hint case.
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>

This now dead code was needed to prevent compile errors while being
staged in -next for v4.5.
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. 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.
Reported-by: NSudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: NVikas C Sajjan <vikas.cha.sajjan@hpe.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
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>

Initialize struct blk_integrity with 0 as blk_integrity_register() takes the
then unitialized struct blk_integrity::flags and ORs it to the resulting block
integrity structure.
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

DMA_CMA is incompatible with SWIOTLB used in enterprise distro
configurations.  Switch to vmalloc() allocations for all resources.
Acked-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Currently phys_to_pfn_t() is an exported symbol to allow nfit_test to
override it and indicate that nfit_test-pmem is not device-mapped.  Now,
we want to enable nfit_test to operate without DMA_CMA and the pmem it
provides will no longer be physically contiguous, i.e. won't be capable
of supporting direct_access requests larger than a page.  Make
pmem_direct_access() a weak symbol so that it can be replaced by the
tools/testing/nvdimm/ version, and move phys_to_pfn_t() to a static
inline now that it no longer needs to be overridden.
Acked-by: NJohannes Thumshirn <jthumshirn@suse.de>
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>

Fail building nfit_test.ko when the configuration is missing pfn device
support.
Reported-by: NMegha Dey <megha.dey@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Prompted by commit 287980e4 "remove lots of IS_ERR_VALUE abuses", I
ran make coccicheck against drivers/nvdimm/ and found that:

	if (IS_ERR(x))
		return PTR_ERR(x);
	return 0;

...can be replaced with PTR_ERR_OR_ZERO().
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Section 5 about BTT's in kernel usage was quite obsolete,
replace it with a simple 'Usage' section that describes how
to set up a BTT namespace using the 'ndctl' utility.
Signed-off-by: NVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Clean up needless calls to the action routine by letting
devm_add_action_or_reset() call it automatically.  This does cause the
disk to registered and immediately unregistered when a memory allocation
fails, but the block layer should be prepared for such an event.
Reported-by: NSudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Pull thermal management fixes from Zhang Rui:

 - fix an ordering issue in cpu cooling that cooling device is
   registered before it's ready (freq_table being populated).
   (Lukasz Luba)

 - fix a missing comment update (Caesar Wang)

* 'for-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  thermal: add the note for set_trip_temp
  thermal: cpu_cooling: fix improper order during initialization

Pull block layer fixes from Jens Axboe:
 "A small collection of fixes for the current series.  This contains:

   - Two fixes for xen-blkfront, from Bob Liu.

   - A bug fix for NVMe, releasing only the specific resources we
     requested.

   - Fix for a debugfs flags entry for nbd, from Josef.

   - Plug fix from Omar, fixing up a case of code being switched between
     two functions.

   - A missing bio_put() for the new discard callers of
     submit_bio_wait(), fixing a regression causing a leak of the bio.
     From Shaun.

   - Improve dirty limit calculation precision in the writeback code,
     fixing a case where setting a limit lower than 1% of memory would
     end up being zero.  From Tejun"

* 'for-linus' of git://git.kernel.dk/linux-block:
  NVMe: Only release requested regions
  xen-blkfront: fix resume issues after a migration
  xen-blkfront: don't call talk_to_blkback when already connected to blkback
  nbd: pass the nbd pointer for flags debugfs
  block: missing bio_put following submit_bio_wait
  blk-mq: really fix plug list flushing for nomerge queues
  writeback: use higher precision calculation in domain_dirty_limits()

Pull GPIO fixes from Linus Walleij:
 "A new bunch of GPIO fixes for v4.7.

  This time I am very grateful that Ricardo Ribalda Delgado went in and
  fixed my stupid refcounting mistakes in the removal path for GPIO
  chips.  I had a feeling something was wrong here and so it was.  It
  exploded on OMAP and it fixes their problem.  Now it should be (more)
  solid.

  The rest i compilation, Kconfig and driver fixes.  Some tagged for
  stable.

  Summary:

   - Fix a NULL pointer dereference when we are searching the GPIO
     device list but one of the devices have been removed (struct
     gpio_chip pointer is NULL).

   - Fix unaligned reference counters: we were ending on +3 after all
     said and done.  It should be 0.  Remove an extraneous get_device(),
     and call cdev_del() followed by device_del() in gpiochip_remove()
     instead and the count goes to zero and calls the release() function
     properly.

   - Fix a compile warning due to a missing #include in the OF/device
     tree portions.

   - Select ANON_INODES for GPIOLIB, we're using that for our character
     device.  Some randconfig tests disclosed the problem.

   - Make sure the Zynq driver clock runs also without CONFIG_PM enabled

   - Fix an off-by-one error in the 104-DIO-48E driver

   - Fix warnings in bcm_kona_gpio_reset()"

* tag 'gpio-v4.7-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: bcm-kona: fix bcm_kona_gpio_reset() warnings
  gpio: select ANON_INODES
  gpio: include <linux/io-mapping.h> in gpiolib-of
  gpiolib: Fix unaligned used of reference counters
  gpiolib: Fix NULL pointer deference
  gpio: zynq: initialize clock even without CONFIG_PM
  gpio: 104-dio-48e: Fix control port offset computation off-by-one error

Pull SCSI fixes from James Bottomley:
 "Two current fixes:

   - one affects Qemu CD ROM emulation, which stopped working after the
     updates in SCSI to require VPD pages from all conformant devices.

     Fix temporarily by blacklisting Qemu (we can relax later when they
     come into compliance).

   - The other is a fix to the optimal transfer size.  We set up a
     minefield for ourselves by being confused about whether the limits
     are in bytes or sectors (SCSI optimal is in blocks and the queue
     parameter is in bytes).

     This tries to fix the problem (wrong setting for queue limits
     max_sectors) and make the problem more obvious by introducing a
     wrapper function"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  sd: Fix rw_max for devices that report an optimal xfer size
  scsi: Add QEMU CD-ROM to VPD Inquiry Blacklist