Driver enumerates NVDIMMs. Besides, for each found System Physical
Address (SPA) range, spaN geom provider is created, which allows
formatting and mounting the region as the normal volume. Also,
/dev/nvdimm_spaN node is created, which can be read/written/mapped by
userspace, the mapping is zero-copy.
No support for block access methods implemented, labels are not
parsed. No management interfaces are provided.
Tested by: Intel, NetApp
Sponsored by: The FreeBSD Foundation
Approved by: re (gjb)
MFC after: 2 weeks