[ofa-general] [PATCH RFC v3 1/2] RDMA/Core: MEM_MGT_EXTENSIONS support

[Roland Dreier]

 > - device-specific alloc/free of physical buffer lists for use in fast
 > register work requests.  This allows devices to allocate this memory as
 > needed (like via dma_alloc_coherent).

I'm looking at how one would implement the MM extensions for mlx4, and
it turns out that in addition to needing to allocate these fastreg page
lists in coherent memory, mlx4 is even going to need to write to the
memory (basically set the lsb of each address for internal device
reasons).  So I think we just need to update the documentation of the
interface so that not only does the page list belong to the device
driver between posting the fastreg work request and completing the
request, but also the device driver is allowed to change the page list
as part of the work request processing.

I don't see any real reason why this would cause problems for consumers;
does this seem OK to other people?