ARM: Add fixed PCI i/o mapping

This adds a fixed virtual mapping for PCI i/o addresses. The mapping is
located at the last 2MB of vmalloc region (0xfee00000-0xff000000). 2MB
is used to align with PMD size, but IO_SPACE_LIMIT is 1MB. The space
is reserved after .map_io and can be mapped at any time later with
pci_ioremap_io. Platforms which need early i/o mapping (e.g. for vga
console) can call pci_map_io_early in their .map_io function.

This has changed completely from the 1st implementation which only
supported creating the static mapping at .map_io.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Nicolas Pitre <nico@linaro.org>
diff --git a/arch/arm/include/asm/mach/map.h b/arch/arm/include/asm/mach/map.h
index a6efcdd..195ac2f 100644
--- a/arch/arm/include/asm/mach/map.h
+++ b/arch/arm/include/asm/mach/map.h
@@ -9,6 +9,9 @@
  *
  *  Page table mapping constructs and function prototypes
  */
+#ifndef __ASM_MACH_MAP_H
+#define __ASM_MACH_MAP_H
+
 #include <asm/io.h>
 
 struct map_desc {
@@ -34,6 +37,8 @@
 
 #ifdef CONFIG_MMU
 extern void iotable_init(struct map_desc *, int);
+extern void vm_reserve_area_early(unsigned long addr, unsigned long size,
+				  void *caller);
 
 struct mem_type;
 extern const struct mem_type *get_mem_type(unsigned int type);
@@ -44,4 +49,7 @@
 			const struct mem_type *mtype);
 #else
 #define iotable_init(map,num)	do { } while (0)
+#define vm_reserve_area_early(a,s,c)	do { } while (0)
+#endif
+
 #endif