Merge tag 'for-linus-20151021' of git://git.infradead.org/intel-iommu

Pull intel-iommu bugfix from David Woodhouse:
"This contains a single fix, for when the IOMMU API is used to overlay
an existing mapping comprised of 4KiB pages, with a mapping that can
use superpages.

For the *first* superpage in the new mapping, we were correctly¹
freeing the old bottom-level page table page and clearing the link to
it, before installing the superpage. For subsequent superpages,
however, we weren't. This causes a memory leak, and a warning about
setting a PTE which is already set.

¹ Well, not *entirely* correctly. We just free the page table pages
right there and then, which is wrong. In fact they should only be
freed *after* the IOTLB is flushed so we know the hardware will no
longer be looking at them.... and in fact I note that the IOTLB
flush is completely missing from the intel_iommu_map() code path,
although it needs to be there if it's permitted to overwrite
existing mappings.

Fixing those is somewhat more intrusive though, and will probably
need to wait for 4.4 at this point"

* tag 'for-linus-20151021' of git://git.infradead.org/intel-iommu:
iommu/vt-d: fix range computation when making room for large pages