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

[Or Gerlitz]

Roland Dreier wrote:
> Also handling highmem is a problem.  ipath just depends on 64BIT so it
> avoids the problem.  I guess mthca could only return a kernel virtual
> address if one exists, and always use DMA for highmem pages.  So that
> isn't really a serious objection.

Roland,

I have mentioned this to Ralph in the past, just want to get ack/nak on 
that from you: also on 64bit arch a block driver (eg SCSI LLD eg 
SRP/iSER/etc) might get from higher level an SG whose pages are **not** 
mapped into the kernel virtual address space. For example this can 
happen with Direct I/O.

Or.