iommu: Introduce direct mapped region handling

Add two new functions to the IOMMU-API to allow the IOMMU
drivers to export the requirements for direct mapped regions
per device.
This is useful for exporting the information in Intel VT-d's
RMRR entries or AMD-Vi's unity mappings.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
(cherry picked from commit a1015c2b99b94cf521603b41debf167114031456)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
2 files changed