powerpc: Create pci_controller_ops.reset_secondary_bus and shim

Add pci_controller_ops.reset_secondary_bus,
shadowing ppc_md.pcibios_reset_secondary_bus.
Add a shim, and changes the callsites to use the shim.

Use pcibios_reset_secondary_bus_shim, as both
pcibios_reset_secondary_bus and pci_reset_secondary_bus
are already taken.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/pci-bridge.h

@@ -34,6 +34,7 @@ struct pci_controller_ops {
 
 	/* Called during PCI resource reassignment */
 	resource_size_t (*window_alignment)(struct pci_bus *, unsigned long type);
+	void		(*reset_secondary_bus)(struct pci_dev *dev);
 };
 
 /*
@@ -346,5 +347,21 @@ static inline resource_size_t pci_window_alignment(struct pci_bus *bus,
 	return 1;
 }
 
+static inline void pcibios_reset_secondary_bus_shim(struct pci_dev *dev)
+{
+	struct pci_controller *phb = pci_bus_to_host(dev->bus);
+
+	if (phb->controller_ops.reset_secondary_bus)
+		phb->controller_ops.reset_secondary_bus(dev);
+	else if (ppc_md.pcibios_reset_secondary_bus)
+		ppc_md.pcibios_reset_secondary_bus(dev);
+	else
+		/*
+		 * Fallback to the generic function if no
+		 * platform-specific one is provided
+		 */
+		pci_reset_secondary_bus(dev);
+}
+
 #endif	/* __KERNEL__ */
 #endif	/* _ASM_POWERPC_PCI_BRIDGE_H */

arch/powerpc/kernel/pci-common.c

@@ -114,12 +114,7 @@ resource_size_t pcibios_window_alignment(struct pci_bus *bus,
 
 void pcibios_reset_secondary_bus(struct pci_dev *dev)
 {
-	if (ppc_md.pcibios_reset_secondary_bus) {
-		ppc_md.pcibios_reset_secondary_bus(dev);
-		return;
-	}
-
-	pci_reset_secondary_bus(dev);
+	pcibios_reset_secondary_bus_shim(dev);
 }
 
 static resource_size_t pcibios_io_size(const struct pci_controller *hose)