diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
index 404a880ea325..d395540ff894 100644
--- a/arch/x86/include/asm/pci.h
+++ b/arch/x86/include/asm/pci.h
@@ -27,6 +27,9 @@ extern struct pci_bus *pci_scan_bus_on_node(int busno, struct pci_ops *ops,
 					    int node);
 extern struct pci_bus *pci_scan_bus_with_sysdata(int busno);
 
+#ifdef CONFIG_PCI
+
+#ifdef CONFIG_PCI_DOMAINS
 static inline int pci_domain_nr(struct pci_bus *bus)
 {
 	struct pci_sysdata *sd = bus->sysdata;
@@ -37,13 +40,12 @@ static inline int pci_proc_domain(struct pci_bus *bus)
 {
 	return pci_domain_nr(bus);
 }
-
+#endif
 
 /* Can be used to override the logic in pci_scan_bus for skipping
    already-configured bus numbers - to be used for buggy BIOSes
    or architectures with incomplete PCI setup by the loader */
 
-#ifdef CONFIG_PCI
 extern unsigned int pcibios_assign_all_busses(void);
 extern int pci_legacy_init(void);
 # ifdef CONFIG_ACPI