[IA64] ioremap() should prefer WB over UC

efi_memmap_init() collects full granules of WB memory, without
regard for whether they also support UC.  So in order for ioremap()
to work for main memory, it must prefer WB mappings when possible.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/mm/ioremap.c

@@ -21,12 +21,12 @@ __ioremap (unsigned long offset, unsigned long size)
 void __iomem *
 ioremap (unsigned long offset, unsigned long size)
 {
-	if (efi_mem_attribute_range(offset, size, EFI_MEMORY_UC))
-		return __ioremap(offset, size);
-
 	if (efi_mem_attribute_range(offset, size, EFI_MEMORY_WB))
 		return phys_to_virt(offset);
 
+	if (efi_mem_attribute_range(offset, size, EFI_MEMORY_UC))
+		return __ioremap(offset, size);
+
 	/*
 	 * Someday this should check ACPI resources so we
 	 * can do the right thing for hot-plugged regions.