diff --git a/sys/arm64/iommu/smmu.c b/sys/arm64/iommu/smmu.c
--- a/sys/arm64/iommu/smmu.c
+++ b/sys/arm64/iommu/smmu.c
@@ -1799,34 +1799,8 @@
 	return (0);
 }
 
-#ifdef DEV_ACPI
 static int
-smmu_pci_get_sid_acpi(device_t child, u_int *xref0, u_int *sid0)
-{
-	uint16_t rid;
-	u_int xref;
-	int seg;
-	int err;
-	int sid;
-
-	seg = pci_get_domain(child);
-	rid = pci_get_rid(child);
-
-	err = acpi_iort_map_pci_smmuv3(seg, rid, &xref, &sid);
-	if (err == 0) {
-		if (sid0)
-			*sid0 = sid;
-		if (xref0)
-			*xref0 = xref;
-	}
-
-	return (err);
-}
-#endif
-
-#ifdef FDT
-static int
-smmu_pci_get_sid_fdt(device_t child, u_int *xref0, u_int *sid0)
+smmu_pci_get_sid(device_t child, u_int *xref0, u_int *sid0)
 {
 	struct pci_id_ofw_iommu pi;
 	int err;
@@ -1841,7 +1815,6 @@
 
 	return (err);
 }
-#endif
 
 static struct iommu_ctx *
 smmu_ctx_alloc(device_t dev, struct iommu_domain *iodom, device_t child,
@@ -1885,11 +1858,7 @@
 
 	pci_class = devclass_find("pci");
 	if (device_get_devclass(device_get_parent(ctx->dev)) == pci_class) {
-#ifdef DEV_ACPI
-		err = smmu_pci_get_sid_acpi(ctx->dev, NULL, &sid);
-#else
-		err = smmu_pci_get_sid_fdt(ctx->dev, NULL, &sid);
-#endif
+		err = smmu_pci_get_sid(ctx->dev, NULL, &sid);
 		if (err)
 			return (err);
 
@@ -2000,11 +1969,7 @@
 
 	sc = device_get_softc(dev);
 
-#ifdef DEV_ACPI
-	err = smmu_pci_get_sid_acpi(child, &xref, NULL);
-#else
-	err = smmu_pci_get_sid_fdt(child, &xref, NULL);
-#endif
+	err = smmu_pci_get_sid(child, &xref, NULL);
 	if (err)
 		return (ENOENT);