[PATCH, RFC] cxl: Add support for CAPP DMA mode

[Stewart Smith]

Ian Munsie <imunsie at au1.ibm.com> writes:
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
> index 3a5ea82..5a42e98 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -2793,7 +2793,9 @@ int pnv_phb_to_cxl_mode(struct pci_dev *dev, uint64_t mode)
>  	pe_info(pe, "Switching PHB to CXL\n");
>  
>  	rc = opal_pci_set_phb_cxl_mode(phb->opal_id, mode, pe->pe_number);
> -	if (rc)
> +	if (rc == OPAL_UNSUPPORTED)
> +		dev_err(&dev->dev, "Required cxl mode not supported by firmware - update skiboot\n");
> +	else if (rc)
>  		dev_err(&dev->dev, "opal_pci_set_phb_cxl_mode failed:
> %i\n", rc);

Could mention version required, which would be skiboot 5.3.x or higher.

This could be something we start doing - there's enough random bits of
functionality we could tell the user exactly what they have to upgrade
to to have work.

-- 
Stewart Smith
OPAL Architect, IBM.