New API for non cache coherent ppc cpu's

Roman Zippel zippel at linux-m68k.org
Wed Nov 21 22:15:39 EST 2001


Hi,

On Tue, 20 Nov 2001, Armin Kuster wrote:

> About a month ago a new API made its way into the ppc,
> consistent_sync_page.

Another one?
We have now 3 APIs for this:
- cache_(push|clear): that's the old m68k API (and also used by APUS)
- dma_cache_(inv|wback|wback_inv): used by mips(64), parisc, sh
- consistent_sync_page: ppc

>  For CONFIG_NOT_COHERENT_CACHE  processors,
> requires
> proper flushing of the page being used.  Please review and provide feed
> back

Two comments:
- I'm not sure about the page argument, although I'd like to see it, the
problem is the drivers usually don't have a page pointer.
- I think it was never defined, what should be done if offset/size isn't
cache line aligned. That's especially a problem in the invalidate only
case. I'd prefer to make this illegal, as it's mostly not a problem for
drivers.

bye, Roman


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