Re: [RFC] generic device DMA implementation

David Gibson (david@gibson.dropbear.id.au)
Fri, 6 Dec 2002 11:08:09 +1100

On Thu, Dec 05, 2002 at 06:49:10PM +0100, Manfred Spraul wrote:
> >
> >
> >Hmm... that doesn't seem sufficient to explain it.
> >
> >Some background: I work with PPC embedded chips (the 4xx family) whose
> >only way to get consistent memory is by entirely disabling the cache.

> What do you mean with "disable"?
> Do you have to disable the cache entirely when you encounter the first
> pci_alloc_consistent() call, or do you disable the cache just for the
> region that is returned by pci_alloc_consistent()?

Just for the region - it is an attribute in the PTE.

-- 
David Gibson			| For every complex problem there is a
david@gibson.dropbear.id.au	| solution which is simple, neat and
				| wrong.
http://www.ozlabs.org/people/dgibson
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