Pull IOMMU SVM fixes from David Woodhouse:
"Minor register size and interrupt acknowledgement fixes which only
showed up in testing on newer hardware, but mostly a fix to the MM
refcount handling to prevent a recursive refcount issue when mmap() is
used on the file descriptor associated with a bound PASID"
* tag 'for-linus-
20160216' of git://git.infradead.org/intel-iommu:
iommu/vt-d: Clear PPR bit to ensure we get more page request interrupts
iommu/vt-d: Fix 64-bit accesses to 32-bit DMAR_GSTS_REG
iommu/vt-d: Fix mm refcounting to hold mm_count not mm_users