[PATCH] IB uverbs: add mthca user MR support

Add support for userspace memory regions (MRs) to mthca.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>