diff --git a/sys/arm64/acpica/acpi_iort.c b/sys/arm64/acpica/acpi_iort.c
--- a/sys/arm64/acpica/acpi_iort.c
+++ b/sys/arm64/acpica/acpi_iort.c
@@ -630,7 +630,7 @@
 }
 
 int
-acpi_iort_map_pci_smmuv3(u_int seg, u_int rid, u_int *xref, u_int *sid)
+acpi_iort_map_pci_smmuv3(u_int seg, u_int rid, uint64_t *xref, u_int *sid)
 {
 	ACPI_IORT_SMMU_V3 *smmu;
 	struct iort_node *node;
@@ -672,7 +672,7 @@
 }
 
 int
-acpi_iort_map_named_smmuv3(const char *devname, u_int rid, u_int *xref,
+acpi_iort_map_named_smmuv3(const char *devname, u_int rid, uint64_t *xref,
     u_int *devid)
 {
 	ACPI_IORT_SMMU_V3 *smmu;
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
@@ -1781,7 +1781,7 @@
 }
 
 static int
-smmu_pci_get_sid(device_t child, u_int *xref0, u_int *sid0)
+smmu_pci_get_sid(device_t child, uintptr_t *xref0, u_int *sid0)
 {
 	struct pci_id_ofw_iommu pi;
 	int err;
@@ -1945,7 +1945,7 @@
 smmu_find(device_t dev, device_t child)
 {
 	struct smmu_softc *sc;
-	u_int xref;
+	uintptr_t xref;
 	int err;
 
 	sc = device_get_softc(dev);
diff --git a/sys/dev/acpica/acpivar.h b/sys/dev/acpica/acpivar.h
--- a/sys/dev/acpica/acpivar.h
+++ b/sys/dev/acpica/acpivar.h
@@ -608,12 +608,13 @@
  * ARM specific ACPI interfaces, relating to IORT table.
  */
 int	acpi_iort_map_pci_msi(u_int seg, u_int rid, u_int *xref, u_int *devid);
-int	acpi_iort_map_pci_smmuv3(u_int seg, u_int rid, u_int *xref, u_int *devid);
+int	acpi_iort_map_pci_smmuv3(u_int seg, u_int rid, uint64_t *xref,
+	    u_int *devid);
 int	acpi_iort_its_lookup(u_int its_id, u_int *xref, int *pxm);
 int	acpi_iort_map_named_msi(const char *devname, u_int rid, u_int *xref,
 	    u_int *devid);
-int	acpi_iort_map_named_smmuv3(const char *devname, u_int rid, u_int *xref,
-	    u_int *devid);
+int	acpi_iort_map_named_smmuv3(const char *devname, u_int rid,
+	    uint64_t *xref, u_int *devid);
 #endif
 #endif /* _KERNEL */
 #endif /* !_ACPIVAR_H_ */
diff --git a/sys/dev/pci/pci_host_generic_acpi.c b/sys/dev/pci/pci_host_generic_acpi.c
--- a/sys/dev/pci/pci_host_generic_acpi.c
+++ b/sys/dev/pci/pci_host_generic_acpi.c
@@ -411,7 +411,8 @@
 {
 	struct generic_pcie_acpi_softc *sc;
 	struct pci_id_ofw_iommu *iommu;
-	u_int iommu_sid, iommu_xref;
+	uint64_t iommu_xref;
+	u_int iommu_sid;
 	uintptr_t rid;
 	int err;
 
diff --git a/sys/dev/pci/pci_host_generic_fdt.c b/sys/dev/pci/pci_host_generic_fdt.c
--- a/sys/dev/pci/pci_host_generic_fdt.c
+++ b/sys/dev/pci/pci_host_generic_fdt.c
@@ -367,7 +367,7 @@
 {
 	struct pci_id_ofw_iommu *iommu;
 	uint32_t iommu_rid;
-	uint32_t iommu_xref;
+	phandle_t iommu_xref;
 	uint16_t pci_rid;
 	phandle_t node;
 	int err;
diff --git a/sys/dev/pci/pcivar.h b/sys/dev/pci/pcivar.h
--- a/sys/dev/pci/pcivar.h
+++ b/sys/dev/pci/pcivar.h
@@ -126,8 +126,8 @@
 };
 
 struct pci_id_ofw_iommu {
+	uintptr_t xref;
 	uint32_t id;
-	uint32_t xref;
 };
 
 /* Interesting values for HyperTransport */