[openib-general] [PATCH v2 1/7] IB/core - Add DMA mapping functions to allow device drivers to interpose

[Roland Dreier]

I think this seems reasonable.  And I think it also provides a way to
address some hypothetical future situation where lowmem pages don't
have a kernel virtual address -- you would just have to use this
type of cookie implementation everywhere.

(Although I don't think using kmap()/kunmap() is really the right
approach -- you should probably just do kmap_atomic()/kunmap_atomic()
only while you are actually using the page.  But the basic approach of
using the dma address as a cookie into a mapping table seems sound to
me -- you are basically doing a real sw iotlb)

Or -- does this seem reasonable to you?

 - R.