of them, and couple them by always performing all operations on all
present IOMMUs. This is required because with the current API there
is no way to determine on which bus a busdma operation is performed.
While being there, clean up the iommu code a bit.
This should be a step in the direction of allow some of larger machines
to work; tests have shown that there still seem to be problems left.
- change the IOMMU support code so that it supports overcommittting the
available DVMA memory, while still allocating as lazily as possible.
This is achieved by limiting the preallocation, and deferring the
allocation to map load time when it fails. In the latter case, the
DVMA memory reserved for unloaded maps can be stolen to free up enough
memory for loading a map.
- allow NULL settings in the method tables, and search the parent tags
until an appropriate implementation is found. This allows to remove some
kluges in the old implementation.
