Benjamin Herrenschmidt benh at
Wed Feb 23 07:43:33 EST 2005

On Tue, 2005-02-22 at 10:24 -0600, John Rose wrote:
> > The reason we request them in the first place is to prevent drivers from
> > mucking around with those bits of hardware no ? (so they fail their own
> > request_region).
> > 
> > I recently added a platform hook to deal with that in a slightly more
> > suitable way, though not all legacy drivers have been fixed yet to use
> > it.
> For the case of dynamically adding a PHB to a system that booted with no
> physical I/O, I need to pick a starting virtual address for the I/O
> region.  I could hard-code to start past these regions, but I'm not sure
> it makes sense for these to exist in the first place.  Would legacy
> drivers even come into play on a purely virtual system?

Well, if you are adding a PHB, it's no longer purely virtual... you
might well have something like a legacy serial card or whatever on this
PGB no ? (though most of these can now properly map their BARs above
0x1000 anyway) or a VGA card ...


More information about the Linuxppc64-dev mailing list