diff --git a/arch/microblaze/include/asm/page.h b/arch/microblaze/include/asm/page.h
index b13463d39b38bc6e4c2c0778688e9fbced8f52c0..8cd320a9ddb4f9aa810baf18f24ab3389b9a5763 100644
--- a/arch/microblaze/include/asm/page.h
+++ b/arch/microblaze/include/asm/page.h
@@ -162,7 +162,7 @@ extern int page_is_ram(unsigned long pfn);
 #  define ARCH_PFN_OFFSET	(PAGE_OFFSET >> PAGE_SHIFT)
 #  else /* CONFIG_MMU */
 #  define ARCH_PFN_OFFSET	(memory_start >> PAGE_SHIFT)
-#  define pfn_valid(pfn)	((pfn) < (max_mapnr + ARCH_PFN_OFFSET))
+#  define pfn_valid(pfn)	((pfn) >= ARCH_PFN_OFFSET && (pfn) < (max_mapnr + ARCH_PFN_OFFSET))
 #  endif /* CONFIG_MMU */
 
 # endif /* __ASSEMBLY__ */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index cf9c69d631f3d8e541b944a72aca06bc52e6896a..d6085d48cb639a6aa588a27ddd0776ba8cdb9962 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6451,7 +6451,6 @@ static void __meminit zone_init_free_lists(struct zone *zone)
 	}
 }
 
-#if !defined(CONFIG_FLAT_NODE_MEM_MAP)
 /*
  * Only struct pages that correspond to ranges defined by memblock.memory
  * are zeroed and initialized by going through __init_single_page() during
@@ -6496,13 +6495,6 @@ static void __init init_unavailable_range(unsigned long spfn,
 		pr_info("On node %d, zone %s: %lld pages in unavailable ranges",
 			node, zone_names[zone], pgcnt);
 }
-#else
-static inline void init_unavailable_range(unsigned long spfn,
-					  unsigned long epfn,
-					  int zone, int node)
-{
-}
-#endif
 
 static void __init memmap_init_zone_range(struct zone *zone,
 					  unsigned long start_pfn,