diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 704608945780..170a3eda9dd3 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -27,7 +27,7 @@
 #include <linux/slab.h>
 
 
-static void pbus_assign_resources_sorted(struct pci_bus *bus)
+static void pbus_assign_resources_sorted(const struct pci_bus *bus)
 {
 	struct pci_dev *dev;
 	struct resource *res;
@@ -495,7 +495,7 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus)
 }
 EXPORT_SYMBOL(pci_bus_size_bridges);
 
-void __ref pci_bus_assign_resources(struct pci_bus *bus)
+void __ref pci_bus_assign_resources(const struct pci_bus *bus)
 {
 	struct pci_bus *b;
 	struct pci_dev *dev;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index a1af2fe00639..7baf2a5db12a 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -708,7 +708,7 @@ ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void
 int pci_vpd_truncate(struct pci_dev *dev, size_t size);
 
 /* Helper functions for low-level code (drivers/pci/setup-[bus,res].c) */
-void pci_bus_assign_resources(struct pci_bus *bus);
+void pci_bus_assign_resources(const struct pci_bus *bus);
 void pci_bus_size_bridges(struct pci_bus *bus);
 int pci_claim_resource(struct pci_dev *, int);
 void pci_assign_unassigned_resources(void);