bootmem: replace node_boot_start in struct bootmem_data

Almost all users of this field need a PFN instead of a physical address,
so replace node_boot_start with node_min_pfn.

[Lee.Schermerhorn@hp.com: fix spurious BUG_ON() in mark_bootmem()]
Signed-off-by: Johannes Weiner <hannes@saeureba.de>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/mn10300/mm/init.c b/arch/mn10300/mm/init.c
index 8c5d88c..8cee387 100644
--- a/arch/mn10300/mm/init.c
+++ b/arch/mn10300/mm/init.c
@@ -67,8 +67,8 @@
 
 	/* declare the sizes of the RAM zones (only use the normal zone) */
 	zones_size[ZONE_NORMAL] =
-		(contig_page_data.bdata->node_low_pfn) -
-		(contig_page_data.bdata->node_boot_start >> PAGE_SHIFT);
+		contig_page_data.bdata->node_low_pfn -
+		contig_page_data.bdata->node_min_pfn;
 
 	/* pass the memory from the bootmem allocator to the main allocator */
 	free_area_init(zones_size);
@@ -87,7 +87,7 @@
 	if (!mem_map)
 		BUG();
 
-#define START_PFN	(contig_page_data.bdata->node_boot_start >> PAGE_SHIFT)
+#define START_PFN	(contig_page_data.bdata->node_min_pfn)
 #define MAX_LOW_PFN	(contig_page_data.bdata->node_low_pfn)
 
 	max_mapnr = num_physpages = MAX_LOW_PFN - START_PFN;