Re: [PATCH 6/8] iommu: Retire bus ops

[Baolu Lu]

On 2023/1/20 3:18, Robin Murphy wrote:
> +	/*
> +	 * For FDT-based systems and ACPI IORT/VIOT, drivers register IOMMU
> +	 * instances with non-NULL fwnodes, and client devices should have been
> +	 * identified with a fwspec by this point. For Intel/AMD/s390/PAMU we
> +	 * can assume a single active driver with global ops, and so grab those
> +	 * from any registered instance, cheekily co-opting the same mechanism.
> +	 */
> +	fwspec = dev_iommu_fwspec_get(dev);
> +	if (fwspec && fwspec->ops)
> +		ops = fwspec->ops;
> +	else
> +		ops = iommu_ops_from_fwnode(NULL);

I'm imagining if Intel/AMD/s390 drivers need to give up global ops.
Is there any way to allow them to make such conversion? I am just
thinking about whether this is a hard limitation for these drivers.

Best regards,
baolu