libnvdimm for 4.15

* Introduce MAP_SYNC and MAP_SHARED_VALIDATE, a mechanism to enable
 'userspace flush' of persistent memory updates via filesystem-dax
  mappings. It arranges for any filesystem metadata updates that may be
  required to satisfy a write fault to also be flushed ("on disk") before
  the kernel returns to userspace from the fault handler. Effectively
  every write-fault that dirties metadata completes an fsync() before
  returning from the fault handler. The new MAP_SHARED_VALIDATE mapping
  type guarantees that the MAP_SYNC flag is validated as supported by the
  filesystem's ->mmap() file operation.

* Add support for the standard ACPI 6.2 label access methods that
  replace the NVDIMM_FAMILY_INTEL (vendor specific) label methods. This
  enables interoperability with environments that only implement the
  standardized methods.

* Add support for the ACPI 6.2 NVDIMM media error injection methods.

* Add support for the NVDIMM_FAMILY_INTEL v1.6 DIMM commands for latch
  last shutdown status, firmware update, SMART error injection, and
  SMART alarm threshold control.

* Cleanup physical address information disclosures to be root-only.

* Fix revalidation of the DIMM "locked label area" status to support
  dynamic unlock of the label area.

* Expand unit test infrastructure to mock the ACPI 6.2 Translate SPA
  (system-physical-address) command and error injection commands.

Acknowledgements that came after the commits were pushed to -next:

957ac8c421ad dax: fix PMD faults on zero-length files
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>

a39e596baa07 xfs: support for synchronous DAX faults
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

7b565c9f965b xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>