On Fri, Jul 31, 2015 at 06:18:29PM +0100, Robin Murphy wrote:

+void arch_teardown_dma_ops(struct device *dev)
+{
+	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+
+	if (domain) {
+		iommu_detach_device(domain, dev);
+		if (domain->type & __IOMMU_DOMAIN_ARM64_IOVA)
+			iommu_put_dma_cookie(domain);
+		if (domain->type & __IOMMU_DOMAIN_ARM64)
+			iommu_domain_free(domain);
+		dev->archdata.dma_ops = NULL;
+	}
+}

When is this called? In case a device gets removed the IOMMU core and
driver should take care of destroying the domain, at least when its a
default-domain. This is part of the iommu-group handling.


	Joerg