svn commit: r192026 - head/share/man/man9

[Marius Strobl]

On Tue, May 12, 2009 at 04:13:06PM -0500, Robert Noland wrote:
> On Tue, 2009-05-12 at 20:56 +0000, Marius Strobl wrote:
> > Author: marius
> > Date: Tue May 12 20:56:34 2009
> > New Revision: 192026
> > URL: http://svn.freebsd.org/changeset/base/192026
> > 
> > Log:
> >   Correct r190283 (partially reverting it) as on sparc64 BUS_DMA_NOCACHE
> >   actually is only valid for bus_dmamap_load().
> 
> Ok, this is getting very confusing...  This means that code has to set
> this flag on both alloc and load to allow for somethine resembling
> consistent behavior.
> 

Personally I don't understand why amd64 and i386 where decided to
implement BUS_DMA_NOCACHE for bus_dmamem_alloc(9) only as this
is less flexible than using it with bus_dmamap_load(9) (which also
is the older existing implementation). Anyway, <sys/bus_dma.h>
documents BUS_DMA_NOCACHE and BUS_DMA_NOWRITE as "non-standard or
specific to only certain architectures" so I think it's okay for
the usage of these flags to differ across them.

Marius