help, trying to invalidate entire icache on 970

Benjamin Herrenschmidt benh at kernel.crashing.org
Wed Apr 6 14:57:29 EST 2005


On Wed, 2005-04-06 at 04:49 +0200, Segher Boessenkool wrote:
> > IIRC to modify an instruction you need the following sequence to do
> > flush the icache correctly:
> >
> > 	dcbst
> > 	sync
> > 	icbi
> > 	isync
> >
> > I can't remember if the 970 actually requires this sequence or not.
> 
> It does not, as the DL1 cache is store-through; i.e., the dcbst insn
> is superfluous here (the sync is required in general, though!)

Isn't dcbst a nop on 970 anyway ?

Ben.





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