[MIPS] Fix sparsemem support.

Move memory_present() in arch/mips/kernel/setup.c. When using sparsemem
extreme, this function does an allocate for bootmem. This would always
fail since init_bootmem hasn't been called yet.
    
Move memory_present after free_bootmem. This only marks actual memory
ranges as present instead of the entire address space.
    
Signed-off-by: Chad Reese  <creese@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/setup.c

@@ -355,8 +355,6 @@ static inline void bootmem_init(void)
 	}
 #endif
 
-	memory_present(0, first_usable_pfn, max_low_pfn);
-
 	/* Initialize the boot-time allocator with low memory only.  */
 	bootmap_size = init_bootmem(first_usable_pfn, max_low_pfn);
 
@@ -410,6 +408,7 @@ static inline void bootmem_init(void)
 
 		/* Register lowmem ranges */
 		free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(size));
+		memory_present(0, curr_pfn, curr_pfn + size - 1);
 	}
 
 	/* Reserve the bootmap memory.  */

arch/mips/mm/init.c

@@ -227,7 +227,7 @@ void __init mem_init(void)
 	for (tmp = 0; tmp < max_low_pfn; tmp++)
 		if (page_is_ram(tmp)) {
 			ram++;
-			if (PageReserved(mem_map+tmp))
+			if (PageReserved(pfn_to_page(tmp)))
 				reservedpages++;
 		}
 

include/asm-mips/page.h

@@ -139,9 +139,11 @@ typedef struct { unsigned long pgprot; } pgprot_t;
 
 #define pfn_to_kaddr(pfn)	__va((pfn) << PAGE_SHIFT)
 
+#ifndef CONFIG_SPARSEMEM
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 #define pfn_valid(pfn)		((pfn) < max_mapnr)
 #endif
+#endif
 
 #define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
 #define virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)

include/asm-mips/sparsemem.h

@@ -0,0 +1,14 @@
+#ifndef _MIPS_SPARSEMEM_H
+#define _MIPS_SPARSEMEM_H
+#ifdef CONFIG_SPARSEMEM
+
+/*
+ * SECTION_SIZE_BITS		2^N: how big each section will be
+ * MAX_PHYSMEM_BITS		2^N: how much memory we can have in that space
+ */
+#define SECTION_SIZE_BITS       28
+#define MAX_PHYSMEM_BITS        35
+
+#endif /* CONFIG_SPARSEMEM */
+#endif /* _MIPS_SPARSEMEM_H */
+