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

[Roland Dreier]

 > Although the driver compiles on 32-bit kernels, it is unsupported
 > and never been tested. All known 64-bit systems don't define
 > CONFIG_HIGHMEM.  In spite of previous emails suggesting that
 > page_address() can return NULL without CONFIG_HIGHMEM defined,
 > the code in include/linux/mm.h doesn't allow it (assuming the
 > page pointer is valid and not some random address).
 > I verified this with Andrew Morton.

Hmm, is there no way to make this work on 32-bit kernels?  I don't
want to do something that we'll have to change again if we want to
make things work on 32-bits.

(And I know that qlogic has no intention of supporting the driver on
32-bit kernels, but we shouldn't make it impossible for someone else
to fix it)