Re: [PATCH] x86_64: set cfg_size for AMD Family 10h in case MMCONFIG is used

Yinghai Lu
2007-09-13T19:23:01Z

On 9/13/07, H. Peter Anvin <hpa@zytor.com> wrote:
> Yinghai Lu wrote:
> >
> > BIOS guys also said that fam 10h need mmconfig via eax accessing, may
> > need OS do sth, so it is safe to stay with MCFG entry for SB like
> > mcp55...
> >
> > but latest kernel already have that workaround to make mmconfig via eax...
> >
>
> This is actually a good point. Since the CPU vendor managed to
> completely fuck up the operation of MMCONFIG itself on this CPU (it's a
> *MEMORY REFERENCE*, guys!), it is actually to be expected and prudent
> that BIOS vendors will drop the MCFG entry. MMCONFIG doesn't actually
> work on this CPU for any system software which doesn't already know to
> work around this particular piece of severe braindamage;
> standards-complicant MMCONFIG isn't supported at all.

if other mmconfig device on x86 is sick of accessing via eax, may need
to provide one fam10h_pci_mmcfg to be assigned to raw_pci_ops instead
and leave pci_mmcfg to default behavior ( *MEMORY REFERENCE*).

YH