diff --git a/sys/dev/acpica/acpi_pci.c b/sys/dev/acpica/acpi_pci.c
index dcc87b45e1ea..a3856e113f3e 100644
--- a/sys/dev/acpica/acpi_pci.c
+++ b/sys/dev/acpica/acpi_pci.c
@@ -280,8 +280,8 @@ acpi_pci_save_handle(ACPI_HANDLE handle, UINT32 level, void *context,
 
 	if (ACPI_FAILURE(acpi_GetInteger(handle, "_ADR", &address)))
 		return_ACPI_STATUS (AE_OK);
-	slot = address >> 16;
-	func = address & 0xffff;
+	slot = ACPI_ADR_PCI_SLOT(address);
+	func = ACPI_ADR_PCI_FUNC(address);
 	if (device_get_children((device_t)context, &devlist, &devcount) != 0)
 		return_ACPI_STATUS (AE_OK);
 	for (i = 0; i < devcount; i++) {
diff --git a/sys/dev/acpica/acpi_pci_link.c b/sys/dev/acpica/acpi_pci_link.c
index 79ba4f8db08b..cc8ec7b3ce3c 100644
--- a/sys/dev/acpica/acpi_pci_link.c
+++ b/sys/dev/acpica/acpi_pci_link.c
@@ -151,7 +151,7 @@ acpi_pci_link_entry_dump(struct acpi_prt_entry *entry)
 	}
 
 	printf(" %d.%d.%d\n", entry->busno,
-	    (int)((entry->prt.Address & 0xffff0000) >> 16),
+	    (int)(ACPI_ADR_PCI_SLOT(entry->prt.Address)),
 	    (int)entry->prt.Pin);
 }
 
@@ -981,7 +981,7 @@ acpi_pci_link_config(device_t dev, ACPI_BUFFER *prtbuf, int busno)
 
 		snprintf(prthint, sizeof(prthint),
 		    "hw.acpi.pci.link.%d.%d.%d.irq", entry->busno,
-		    (int)((entry->prt.Address & 0xffff0000) >> 16),
+		    (int)(ACPI_ADR_PCI_SLOT(entry->prt.Address)),
 		    (int)entry->prt.Pin);
 
 		if (getenv_int(prthint, &irq) == 0)
@@ -1069,7 +1069,7 @@ acpi_pci_find_prt(device_t pcibdev, device_t dev, int pin)
 	TAILQ_FOREACH(entry, &acpi_prt_entries, links) {
 		prt = &entry->prt;
 		if (entry->busno == pci_get_bus(dev) &&
-		    (prt->Address & 0xffff0000) >> 16 == pci_get_slot(dev) &&
+		    ACPI_ADR_PCI_SLOT(prt->Address) == pci_get_slot(dev) &&
 		    prt->Pin == pin)
 			break;
 	}
diff --git a/sys/dev/acpica/acpi_pcib_acpi.c b/sys/dev/acpica/acpi_pcib_acpi.c
index d37db32b0c95..350bb89b6e56 100644
--- a/sys/dev/acpica/acpi_pcib_acpi.c
+++ b/sys/dev/acpica/acpi_pcib_acpi.c
@@ -188,8 +188,8 @@ acpi_pcib_acpi_attach(device_t dev)
 		device_printf(dev, "couldn't find _ADR\n");
 	} else {
 	    /* XXX: We assume bus 0. */
-	    slot = addr >> 16;
-	    func = addr & 0xffff;
+	    slot = ACPI_ADR_PCI_SLOT(addr);
+	    func = ACPI_ADR_PCI_FUNC(addr);
 	    if (bootverbose)
 		device_printf(dev, "reading config registers from 0:%d:%d\n",
 		    slot, func);
diff --git a/sys/dev/acpica/acpivar.h b/sys/dev/acpica/acpivar.h
index 811c3edd871e..37221607a845 100644
--- a/sys/dev/acpica/acpivar.h
+++ b/sys/dev/acpica/acpivar.h
@@ -98,6 +98,10 @@ struct acpi_prw_data {
 /* Flags for each device defined in the AML namespace. */
 #define ACPI_FLAG_WAKE_ENABLED	0x1
 
+/* Macros for extracting parts of a PCI address from an _ADR value. */
+#define	ACPI_ADR_PCI_SLOT(adr)	(((adr) & 0xffff0000) >> 16)
+#define	ACPI_ADR_PCI_FUNC(adr)	((adr) & 0xffff)
+
 /*
  * Entry points to ACPI from above are global functions defined in this
  * file, sysctls, and I/O on the control device.  Entry points from below