diff --git a/sys/compat/linuxkpi/common/include/linux/iommu.h b/sys/compat/linuxkpi/common/include/linux/iommu.h
new file mode 100644
--- /dev/null
+++ b/sys/compat/linuxkpi/common/include/linux/iommu.h
@@ -0,0 +1,29 @@
+/* Public domain. */
+
+#ifndef _LINUXKPI_LINUX_IOMMU_H_
+#define	_LINUXKPI_LINUX_IOMMU_H_
+
+#include <linux/device.h>
+
+#define	__IOMMU_DOMAIN_PAGING	(1U << 0)
+#define	__IOMMU_DOMAIN_DMA_API	(1U << 1)
+#define	__IOMMU_DOMAIN_PT	(1U << 2)
+#define	__IOMMU_DOMAIN_DMA_FQ	(1U << 3)
+
+#define	IOMMU_DOMAIN_BLOCKED	(0U)
+#define	IOMMU_DOMAIN_IDENTITY	(__IOMMU_DOMAIN_PT)
+#define	IOMMU_DOMAIN_UNMANAGED	(__IOMMU_DOMAIN_PAGING)
+#define	IOMMU_DOMAIN_DMA	(__IOMMU_DOMAIN_PAGING | __IOMMU_DOMAIN_DMA_API)
+#define	IOMMU_DOMAIN_DMA_FQ	(__IOMMU_DOMAIN_PAGING | __IOMMU_DOMAIN_DMA_API | __IOMMU_DOMAIN_DMA_FQ)
+
+struct iommu_domain {
+	unsigned int type;
+};
+
+static inline struct iommu_domain *
+iommu_get_domain_for_dev(struct device *dev __unused)
+{
+	return (NULL);
+}
+
+#endif /* _LINUXKPI_LINUX_IOMMU_H_ */