Re: [RFC PATCH] PCI MMCONFIG: add validation against ACPI motherboard resources

Jesse Barnes
2007-05-02T05:27:43Z

On Tuesday, May 01, 2007, Jesse Barnes wrote:
> > I'm testing it now on my 965...
>
> Bah... nevermind Robert, I see you're doing this already in
> pci_mmcfg_reject_broken. I'm about to reboot & test now.

Ok, I've tested a bit on my 965 (after re-adding my old patch to support
it) and the new checks are more complete, but my BIOS still appears to be
buggy.

The extended config space (as defined by the register) is at 0xf0000000
(full value is 0xf0000003 indicating 128M enabled). The ACPI MCFG table
has this space reserved according to Robert's new code, but the machine
hangs due to the address space aliasing Olivier mentioned awhile back. I
don't have a PCIe card to test with (or any devices that require extended
config space that I know of) so I can't really tell if Windows supports
PCIe on this platform, but if it does I don't see how it would w/o having
a full bridge driver and sophisticated address space allocation builtin.

I'm going to try updating my BIOS, but if that doesn't solve this problem,
I'm not sure what we can do about it. Should pci_mmcfg_insert_resources
check for conflicts? Should we just blacklist certain boards? I can try
pinging our BIOS folks about this board to see what was intended, but I'm
sure this won't be the only board we have problems with, so we'll need to
address it generically somehow.

Thanks,
Jesse