Re: Re: [PATCH] PCI: Enable io space 1k granularity for intel cpu root port

Zhou Shengqing
2024-06-24T08:17:02Z

> > That seems like a really broken kind of encapsulation. I'd be
> > surprised if there were not a bit in each of those Root Ports that
> > indicates this.

> Your understanding is completely correct.intel ICX SPR RMR (even GNR)
> CPU EDS Vol2(register) spec says "This bit when set, enables 1K granularity
> for I/O space decode in each of the virtual P2P bridges corresponding to
> root ports,and DMI ports." it targets all P2P bridges within the same root bus,
> not the root port itself.The root ports configuration space doesn't have a
> "EN1K" bit.

For this reason, it doesn't seem feasible to implement this patch in
fixup.c or quirks.c.Would it be reasonable to implement this patch in the
pcibios_fixup_bus function in /x86/pci/common.c? I also think adding this patch
in pci/probe.c is not a good idea.