On Apr 5, 2011, at 6:39 PM, Benjamin Herrenschmidt wrote: > On Tue, 2011-04-05 at 07:41 -0500, Kumar Gala wrote: >>> Rework it to make it a bit clearer, and also correct. We want 3 save >>> areas, each EX_TLB_SIZE _bytes_. >> >> Where does the 3 come from? I have a guess, and think its possible we >> (FSL) want 4? > > Wrong guess :-) It's not about exception levels. It's about how much > the handler can re-enter (2 with E.PT, 3 with virtual linear) > > For MC's, CRITs etc... which we don't support on Book3E 64-bit at this > stage, you'll have to probably backup the whole area... that or move > the TLB frame pointer SPR to a separate set of 3 levels, but then you'd > have to fix the code that makes assumption about level 0 being at a > fixed offset in the PACA and instead use alignment tricks. We need that > because that's how we "reset" the TLB frame when a second level finds > a fault. > > Cheers, > Ben.
Gotcha, can we add a comment here about what the '3' is about. - k _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
