Re: [PATCH 2/6] Introduce CONFIG_ZONE_DMA

Martin Schwidefsky
2006-09-18T14:08:07Z

On Mon, 2006-09-18 at 14:55 +0100, Christoph Hellwig wrote:
> > Second, arches may use ZONE_DMA in an unknown way. We set CONFIG_ZONE_DMA
> > for all arches that do not set CONFIG_GENERIC_ISA_DMA in order to insure
> > backwards compatibility. The arches may later undefine ZONE_DMA
> > if their arch code has been verified to not depend on ZONE_DMA.
>
> Let's pass this on to linux-arch so that the arch maintainers can give input
> whether they need ZONE_DMA or not. If this just sneaks in unseen I'd bet
> various architectures will just keept it around despite not needing it.

s390 needs ZONE_DMA for the memory area below 2GB. That is required for
the control structure of channel based I/O. It is not ISA but
conceptually related. Can we rename GENERIC_ISA_DMA into GENERIC_IO_DMA
or something similar?

--
blue skies,
Martin.

Martin Schwidefsky
Linux for zSeries Development & Services
IBM Deutschland Entwicklung GmbH

"Reality continues to ruin my life." - Calvin.