It is really that easy to get things working, although the fastest solution
may be different. We plan to play IO page table tricks in 2.3 to see if
dynamic DMA allocation (already done on sun4c and sun4d) could be a win
there. Then the drivers just have to use some yet-to-be designed arch
independent interface to grab a DMA area and to release it later (sparc
drivers already use something like that, but it would be good to introduce
it as a generic interface which would just give the dma handle
and a nop on release when no grabbing/releasing is necessary (ie. in sparc64
case the address is either below 4GB-delta PA)).
We'll have to rethink the readl/... etc. interface in 2.3 anyway IMHO, so
such thing could be part of the new MMIO interface. (matroxfb is a good
example what problems are with current Linux arch independent interface
(if there actually is any)).
Cheers,
Jakub
___________________________________________________________________
Jakub Jelinek | jj@sunsite.mff.cuni.cz | http://sunsite.mff.cuni.cz
Administrator of SunSITE Czech Republic, MFF, Charles University
___________________________________________________________________
UltraLinux | http://ultra.linux.cz/ | http://ultra.penguin.cz/
Linux version 2.2.0-final on a sparc64 machine (3958.37 BogoMips)
___________________________________________________________________
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/