On Wed, May 20, 2026 at 11:20:43AM -0300, Jason Gunthorpe wrote:

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

quoted

quoted

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.

OK. Can we use pci_ats_required()?

CXL spec explicitly used "ATS" when stating the requirement of
CXL.cache). And it'd fit into the existing pci_ats_ functions.

Nicolin