powerpc: Create pci_controller_ops.dma_bus_setup and shim

Add pci_controller_ops.dma_bus_setup, shadowing ppc_md.pci_dma_bus_setup.
Add a shim, and changes the callsites to use the shim.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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

@@ -19,6 +19,7 @@ struct device_node;
  */
 struct pci_controller_ops {
 	void		(*dma_dev_setup)(struct pci_dev *dev);
+	void		(*dma_bus_setup)(struct pci_bus *bus);
 };
 
 /*
@@ -281,5 +282,15 @@ static inline void pci_dma_dev_setup(struct pci_dev *dev)
 		ppc_md.pci_dma_dev_setup(dev);
 }
 
+static inline void pci_dma_bus_setup(struct pci_bus *bus)
+{
+	struct pci_controller *phb = pci_bus_to_host(bus);
+
+	if (phb->controller_ops.dma_bus_setup)
+		phb->controller_ops.dma_bus_setup(bus);
+	else if (ppc_md.pci_dma_bus_setup)
+		ppc_md.pci_dma_bus_setup(bus);
+}
+
 #endif	/* __KERNEL__ */
 #endif	/* _ASM_POWERPC_PCI_BRIDGE_H */

arch/powerpc/kernel/pci-common.c

@@ -953,8 +953,7 @@ void pcibios_setup_bus_self(struct pci_bus *bus)
 		ppc_md.pcibios_fixup_bus(bus);
 
 	/* Setup bus DMA mappings */
-	if (ppc_md.pci_dma_bus_setup)
-		ppc_md.pci_dma_bus_setup(bus);
+	pci_dma_bus_setup(bus);
 }
 
 static void pcibios_setup_device(struct pci_dev *dev)