Re: [PATCH V5 3/5] iommu/dma-iommu: Handle deferred devices

+static int handle_deferred_device(struct device *dev,
+	struct iommu_domain *domain)

Nitick: we usually use double tab indents (or indents to after
the opening brace) for multi-line prototyped.

+	if (!is_kdump_kernel())
+		return 0;
+
+	if (unlikely(ops->is_attach_deferred &&
+		ops->is_attach_deferred(domain, dev)))
+		return iommu_attach_device(domain, dev);

And for multi-line conditionals we also use two-tab indents.