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

[Jason Gunthorpe]

On Tue, May 19, 2026 at 06:04:18PM -0700, Nicolin Chen wrote:

> > Yeah, that's fair, so let's rename it to 
> > 
> > pci_translated_required()
> > 
> > ie the device requires translated requests to function. This is what
> > CXL.cache implies (IIRC I was told the spec specifically says this)
> > 
> > Requiring translated requests implies you have to enable ATS in the
> > system.
> 
> Perhaps we could let IOMMU drivers check:
>   pci_cxl_is_cache_capable() || pci_dev_specific_is_pre_cxl()
> directly?

I'd rather have a single function.

Jason