[PATCH v4 1/3] PCI: Allow ATS to be always on for CXL.cache capable devices

[Jason Gunthorpe]

On Tue, May 19, 2026 at 02:36:49PM -0500, Bjorn Helgaas wrote:
> One motivation for putting this in the PCI core was to use the quirk
> infrastructure, but this series doesn't use any of that.  It doesn't
> declare any fixups, e.g., DECLARE_PCI_FIXUP_FINAL, and it doesn't
> update any state cached by the PCI core.

It works like the acs quirks that are in the quirks file, which are
also arguably only used by iommu too :)

I'm not keen on spreading lists of device ids for PCI quirks to iommu
files, but it would be OK to move pci_ats_always_on() to
iommu_ats_always_on() that calls the PCI quirk function.

Thanks,
Jason