On Fri, 2009-04-03 at 00:52 +0200, Alexander Graf wrote: > > That sounds a lot like what I imlemented for real mode on 970. I > assume the PID is similar to a full SLB context and AS=1/AS=0 is > just > another bit that could as well be in the PID?
Mostly... however, when an interrupt occurs, AS is set to 0 and PID remains unchanged. Also, AS can have different settings for instruction and data fetches. (I've been abbreviating as "MSR[AS]", but technically I should be writing "MSR[IS] for instructions or MSR[DS] for data"). > So what we do on 970[1] is we treat real mode as "yet another vsid". > 970 translates EA -> VA -> RA. It looks like booke does the same, with > the VSID coming from the PID. Exactly -- Book E uses AS | PID to provide the VSID, while Book S uses the SLB. The Book E way is much simpler, and also avoids the effective address collision problem we ran into on 970, because AS/PID don't depend on the EA. -- Hollis Blanchard IBM Linux Technology Center -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
