Re: [PATCH 5/9] iommu/amd: Implement .flush_np_cache

[Christoph Hellwig]

> +static void amd_iommu_flush_np_cache(struct iommu_domain *domain,
> +		unsigned long iova, size_t size)
> +{
> +	struct protection_domain *dom = to_pdomain(domain);
> +
> +	if (unlikely(amd_iommu_np_cache)) {

Is this case really so unlikely that it needs a static branch prediction
hint?