On Tue, 2009-11-24 at 22:00 +0100, Segher Boessenkool wrote:

Sure, the memory controllers don't do coherency.  I'm slightly worried
about two things:
1) Will the generic code use M=0 as well?  Is it a problem if it  
doesn't?

We can make it not do it.

2) Do lwarx. etc. work in M=0? 

They should hopefully... as long as you don't rely on the reservation
blowing as a result of a DMA write.

Cheers,
Ben