Re: [PATCH v11 2/9] s390/pci: Add architecture specific resource/bus address translation

Farhan Ali
2026-03-25T17:44:46Z

On 3/25/2026 4:58 AM, Ilpo Järvinen wrote:
> On Tue, 24 Mar 2026, Bjorn Helgaas wrote:
>
>> [+cc Ilpo just for awareness; I assume there's nothing Linux can
>> actually *do* with s390 PCI resources?]
> I'm somewhat aware they've this speciality (and besides that, I'm
> waiting for this change in order to proceed with the series to detect
> which resources are properly setup when we enumerate them which got
> reverted earlier).
>
> An additional thought related to this, there's IORESOURCE_PCI_FIXED
> results in skipping most of the resource fitting and assignment code, so
> if nothing really should touch these resources, perhaps that flag might be
> of some help.

I need to look into IORESOURCE_PCI_FIXED. Looking at briefly I think it
may work for pci_restore_bars(), though need to check other callers of
pcibios_resource_to_bus() to see if they will overwrite the BARs. But
for now will remove this patch as part of this series and send it out as
a separate patch.

Thanks

Farhan

>