powerpc/pasemi: Clean up pasemi iommu table initializations

No need for empty helpers with iommu off, the ppc_md hooks are optional.

The direct_dma_ops are the default pci_dma_ops, so no need to set in the
them iommu off case.

No need to set the device tree device_node pci node iommu pointer, its
only used for dlpar remove.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/pasemi/iommu.c

@@ -156,20 +156,12 @@ static void iommu_table_iobmap_setup(void)
 
 static void pci_dma_bus_setup_pasemi(struct pci_bus *bus)
 {
-	struct device_node *dn;
-
 	pr_debug("pci_dma_bus_setup, bus %p, bus->self %p\n", bus, bus->self);
 
 	if (!iommu_table_iobmap_inited) {
 		iommu_table_iobmap_inited = 1;
 		iommu_table_iobmap_setup();
 	}
-
-	dn = pci_bus_to_OF_node(bus);
-
-	if (dn)
-		PCI_DN(dn)->iommu_table = &iommu_table_iobmap;
-
 }
 
 
@@ -192,9 +184,6 @@ static void pci_dma_dev_setup_pasemi(struct pci_dev *dev)
 	set_iommu_table_base(&dev->dev, &iommu_table_iobmap);
 }
 
-static void pci_dma_bus_setup_null(struct pci_bus *b) { }
-static void pci_dma_dev_setup_null(struct pci_dev *d) { }
-
 int __init iob_init(struct device_node *dn)
 {
 	unsigned long tmp;
@@ -251,14 +240,8 @@ void __init iommu_init_early_pasemi(void)
 	iommu_off = of_chosen &&
 			of_get_property(of_chosen, "linux,iommu-off", NULL);
 #endif
-	if (iommu_off) {
-		/* Direct I/O, IOMMU off */
-		ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_null;
-		ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_null;
-		set_pci_dma_ops(&dma_direct_ops);
-
+	if (iommu_off)
 		return;
-	}
 
 	iob_init(NULL);