[ARM] Fix nommu build

Fix warnings and errors in arch/arm/mm for nommu build.
Remove commented out function prototype in pgtable-nommu.h

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/mm.h

@@ -1,4 +1,7 @@
 /* the upper-most page table pointer */
+
+#ifdef CONFIG_MMU
+
 extern pmd_t *top_pmd;
 
 #define TOP_PTE(x)	pte_offset_kernel(top_pmd, x)
@@ -13,6 +16,8 @@ static inline pmd_t *pmd_off_k(unsigned long virt)
 	return pmd_off(pgd_offset_k(virt), virt);
 }
 
+#endif
+
 struct map_desc;
 struct meminfo;
 struct pglist_data;

arch/arm/mm/nommu.c

@@ -6,10 +6,12 @@
 #include <linux/module.h>
 #include <linux/mm.h>
 #include <linux/pagemap.h>
+#include <linux/bootmem.h>
 
 #include <asm/cacheflush.h>
 #include <asm/io.h>
 #include <asm/page.h>
+#include <asm/mach/arch.h>
 
 #include "mm.h"
 
@@ -76,7 +78,7 @@ void __iomem *__ioremap(unsigned long phys_addr, size_t size,
 }
 EXPORT_SYMBOL(__ioremap);
 
-void __iounmap(void __iomem *addr)
+void __iounmap(volatile void __iomem *addr)
 {
 }
 EXPORT_SYMBOL(__iounmap);

include/asm-arm/pgtable-nommu.h

@@ -44,7 +44,6 @@
 #define PAGE_READONLY	__pgprot(0)
 #define PAGE_KERNEL	__pgprot(0)
 
-//extern void paging_init(struct meminfo *, struct machine_desc *);
 #define swapper_pg_dir ((pgd_t *) 0)
 
 #define __swp_type(x)		(0)