The meye hardware needs to access the main memory for DMA using
32 bit addresses. The previous version of the meye driver used
dma_addr_t types to build those addresses and ensured that
sizeof(dma_addr_t) = 4 by disabling HIGHMEM64G in Kconfig.

However, this way of doing it also makes meye unavailable on
some kernel configurations. As Arjan said previously, future Fedora
kernels may have HIGHMEM64G activated by default (davej says it won't
happen, at least for now...). Other distributions may do the same and
this will require meye users to recompile the whole kernel.

The attached patch makes the meye driver use dma_addr_t addresses 
internally, but converts them to u32 before giving them to the
hardware.
Signed-off-by: Stelian Pop <stelian@popies.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>