This patch implements the necessary infrastructure and hypercalls for
sPAPR's TCE (Translation Control Entry) IOMMU mechanism.  This is necessary
for all virtual IO devices which do DMA (i.e. nearly all of them).
Signed-off-by: NBen Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>