[PATCH 0/6] Properly detect swiotlb.

[jgli...@redhat.com]

So this is only build tested as i am away from hardware right now.
Idea is to provide reliable way to check if swiotlb is in use for
a device or not. It seems swiotlb_nr_tbl() is no longer reliable
for that.

Please test.

Cheers,
Jérôme Glisse