powerpc/PCI: compute I/O space bus-to-resource offset consistently

Make sure we compute CPU addresses (resource start/end) the same way both
when we set up the I/O aperture (hose->io_resource) and when we use
pcibios_bus_to_resource() to convert BAR values into resources.

This fixes a build failure ("cast from pointer to integer of different
size" in configs where resource_size_t is 64 bits but pointers are 32 bits)
I introduced in 6c5705fec63d.

Acked-By: Benjamin Herrenschmidt <[e-mail]>
Signed-off-by: Bjorn Helgaas <[e-mail]>
Signed-off-by: Jesse Barnes <[e-mail]>

arch/powerpc/include/asm/pci.h

···
 				 const struct resource *rsrc,
 				 resource_size_t *start, resource_size_t *end);
 
+extern resource_size_t pcibios_io_space_offset(struct pci_controller *hose);
 extern void pcibios_setup_bus_devices(struct pci_bus *bus);
 extern void pcibios_setup_bus_self(struct pci_bus *bus);
 extern void pcibios_setup_phb_io_space(struct pci_controller *hose);

arch/powerpc/kernel/pci-common.c

···
 	return pci_enable_resources(dev, mask);
 }
 
+resource_size_t pcibios_io_space_offset(struct pci_controller *hose)
+{
+	return (unsigned long) hose->io_base_virt - _IO_BASE;
+}
+
 static void __devinit pcibios_setup_phb_resources(struct pci_controller *hose, struct list_head *resources)
 {
 	struct resource *res;
···
 		 (unsigned long long)res->start,
 		 (unsigned long long)res->end,
 		 (unsigned long)res->flags);
-	pci_add_resource_offset(resources, res,
-			(resource_size_t) hose->io_base_virt - _IO_BASE);
+	pci_add_resource_offset(resources, res, pcibios_io_space_offset(hose));
 
 	/* Hookup PHB Memory resources */
 	for (i = 0; i < 3; ++i) {

arch/powerpc/kernel/pci_32.c

···
 	struct resource *res = &hose->io_resource;
 
 	/* Fixup IO space offset */
-	io_offset = (unsigned long)hose->io_base_virt - isa_io_base;
-	res->start = (res->start + io_offset) & 0xffffffffu;
-	res->end = (res->end + io_offset) & 0xffffffffu;
+	io_offset = pcibios_io_space_offset(hose);
+	res->start += io_offset;
+	res->end += io_offset;
 }
 
 static int __init pcibios_init(void)

arch/powerpc/kernel/pci_64.c

···
 		return -ENOMEM;
 
 	/* Fixup hose IO resource */
-	io_virt_offset = (unsigned long)hose->io_base_virt - _IO_BASE;
+	io_virt_offset = pcibios_io_space_offset(hose);
 	hose->io_resource.start += io_virt_offset;
 	hose->io_resource.end += io_virt_offset;