ia64/PCI: Use ioremap() instead of open-coded equivalent

Depositing __IA64_UNCACHED_OFFSET in the upper address bits is essentially
equivalent to ioremap(): it converts a CPU physical address to a virtual
address using the ia64 uncacheable identity map.

Call ioremap() instead of doing the phys-to-virt conversion manually with
__IA64_UNCACHED_OFFSET.

Note that this makes it obvious that (a) we're putting a virtual address in
a struct resource, and (b) we're passing a virtual address to ioremap()
below in the PCI_ROM_RESOURCE case.  These are both pre-existing problems
that I'll resolve next.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

arch/ia64/sn/kernel/io_init.c

@@ -185,9 +185,8 @@ sn_io_slot_fixup(struct pci_dev *dev)
 		if (size == 0)
 			continue;
 
-		addr = pcidev_info->pdi_pio_mapped_addr[idx];
-		addr = ((addr << 4) >> 4) | __IA64_UNCACHED_OFFSET;
-		res->start = addr;
+		res->start = ioremap(pcidev_info->pdi_pio_mapped_addr[idx],
+				     size + 1);
 		res->end = addr + size;
 
 		/*