Index: head/sys/dev/acpica/acpi_pci.c
===================================================================
--- head/sys/dev/acpica/acpi_pci.c
+++ head/sys/dev/acpica/acpi_pci.c
@@ -456,15 +456,15 @@
 }
 
 #ifdef ACPI_DMAR
-bus_dma_tag_t dmar_get_dma_tag(device_t dev, device_t child);
+bus_dma_tag_t acpi_iommu_get_dma_tag(device_t dev, device_t child);
 static bus_dma_tag_t
 acpi_pci_get_dma_tag(device_t bus, device_t child)
 {
 	bus_dma_tag_t tag;
 
 	if (device_get_parent(child) == bus) {
-		/* try dmar and return if it works */
-		tag = dmar_get_dma_tag(bus, child);
+		/* try iommu and return if it works */
+		tag = acpi_iommu_get_dma_tag(bus, child);
 	} else
 		tag = NULL;
 	if (tag == NULL)
Index: head/sys/dev/pci/pci.c
===================================================================
--- head/sys/dev/pci/pci.c
+++ head/sys/dev/pci/pci.c
@@ -5682,7 +5682,7 @@
 }
 
 #ifdef ACPI_DMAR
-bus_dma_tag_t dmar_get_dma_tag(device_t dev, device_t child);
+bus_dma_tag_t acpi_iommu_get_dma_tag(device_t dev, device_t child);
 bus_dma_tag_t
 pci_get_dma_tag(device_t bus, device_t dev)
 {
@@ -5690,8 +5690,8 @@
 	struct pci_softc *sc;
 
 	if (device_get_parent(dev) == bus) {
-		/* try dmar and return if it works */
-		tag = dmar_get_dma_tag(bus, dev);
+		/* try iommu and return if it works */
+		tag = acpi_iommu_get_dma_tag(bus, dev);
 	} else
 		tag = NULL;
 	if (tag == NULL) {
Index: head/sys/x86/iommu/busdma_dmar.h
===================================================================
--- head/sys/x86/iommu/busdma_dmar.h
+++ head/sys/x86/iommu/busdma_dmar.h
@@ -62,6 +62,6 @@
 
 extern struct bus_dma_impl bus_dma_dmar_impl;
 
-bus_dma_tag_t dmar_get_dma_tag(device_t dev, device_t child);
+bus_dma_tag_t acpi_iommu_get_dma_tag(device_t dev, device_t child);
 
 #endif
Index: head/sys/x86/iommu/busdma_dmar.c
===================================================================
--- head/sys/x86/iommu/busdma_dmar.c
+++ head/sys/x86/iommu/busdma_dmar.c
@@ -269,7 +269,7 @@
 }
 
 bus_dma_tag_t
-dmar_get_dma_tag(device_t dev, device_t child)
+acpi_iommu_get_dma_tag(device_t dev, device_t child)
 {
 	struct dmar_unit *dmar;
 	struct dmar_ctx *ctx;