diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 12aae706cb27ce46a06672c37c665baa9d463b3b..83de0273d4742376e32ae7400ac4f4bce473d4be 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -329,7 +329,7 @@ config NODES_SHIFT
 # VIRTUAL_MEM_MAP has been retained for historical reasons.
 config VIRTUAL_MEM_MAP
 	bool "Virtual mem map"
-	depends on !SPARSEMEM
+	depends on !SPARSEMEM && !FLATMEM
 	default y
 	help
 	  Say Y to compile the kernel with support for a virtual mem map.
diff --git a/arch/ia64/include/asm/meminit.h b/arch/ia64/include/asm/meminit.h
index 092f1c91b36c02e890ca2417a5e2c841bf750691..e789c0818edbcf6d5eb4c37bf15f672ea5f1bf66 100644
--- a/arch/ia64/include/asm/meminit.h
+++ b/arch/ia64/include/asm/meminit.h
@@ -59,10 +59,8 @@ extern int reserve_elfcorehdr(u64 *start, u64 *end);
 extern int register_active_ranges(u64 start, u64 len, int nid);
 
 #ifdef CONFIG_VIRTUAL_MEM_MAP
-# define LARGE_GAP	0x40000000 /* Use virtual mem map if hole is > than this */
   extern unsigned long VMALLOC_END;
   extern struct page *vmem_map;
-  extern int find_largest_hole(u64 start, u64 end, void *arg);
   extern int create_mem_map_page_table(u64 start, u64 end, void *arg);
   extern int vmemmap_find_next_valid_pfn(int, int);
 #else
diff --git a/arch/ia64/mm/contig.c b/arch/ia64/mm/contig.c
index ba81d8cb00592b304660797cdbe97687bbb0d44e..bfc4ecd0a2ab6cf72cb4689d0d60f5870adca5cb 100644
--- a/arch/ia64/mm/contig.c
+++ b/arch/ia64/mm/contig.c
@@ -19,15 +19,12 @@
 #include <linux/mm.h>
 #include <linux/nmi.h>
 #include <linux/swap.h>
+#include <linux/sizes.h>
 
 #include <asm/meminit.h>
 #include <asm/sections.h>
 #include <asm/mca.h>
 
-#ifdef CONFIG_VIRTUAL_MEM_MAP
-static unsigned long max_gap;
-#endif
-
 /* physical address where the bootmem map is located */
 unsigned long bootmap_start;
 
@@ -166,33 +163,30 @@ find_memory (void)
 	alloc_per_cpu_data();
 }
 
-static void __init virtual_map_init(void)
+static int __init find_largest_hole(u64 start, u64 end, void *arg)
 {
-#ifdef CONFIG_VIRTUAL_MEM_MAP
-	efi_memmap_walk(find_largest_hole, (u64 *)&max_gap);
-	if (max_gap < LARGE_GAP) {
-		vmem_map = (struct page *) 0;
-	} else {
-		unsigned long map_size;
+	u64 *max_gap = arg;
 
-		/* allocate virtual_mem_map */
+	static u64 last_end = PAGE_OFFSET;
 
-		map_size = PAGE_ALIGN(ALIGN(max_low_pfn, MAX_ORDER_NR_PAGES) *
-			sizeof(struct page));
-		VMALLOC_END -= map_size;
-		vmem_map = (struct page *) VMALLOC_END;
-		efi_memmap_walk(create_mem_map_page_table, NULL);
+	/* NOTE: this algorithm assumes efi memmap table is ordered */
 
-		/*
-		 * alloc_node_mem_map makes an adjustment for mem_map
-		 * which isn't compatible with vmem_map.
-		 */
-		NODE_DATA(0)->node_mem_map = vmem_map +
-			find_min_pfn_with_active_regions();
+	if (*max_gap < (start - last_end))
+		*max_gap = start - last_end;
+	last_end = end;
+	return 0;
+}
 
-		printk("Virtual mem_map starts at 0x%p\n", mem_map);
-	}
-#endif /* !CONFIG_VIRTUAL_MEM_MAP */
+static void __init verify_gap_absence(void)
+{
+	unsigned long max_gap;
+
+	/* Forbid FLATMEM if hole is > than 1G */
+	efi_memmap_walk(find_largest_hole, (u64 *)&max_gap);
+	if (max_gap >= SZ_1G)
+		panic("Cannot use FLATMEM with %ldMB hole\n"
+		      "Please switch over to SPARSEMEM\n",
+		      (max_gap >> 20));
 }
 
 /*
@@ -210,7 +204,7 @@ paging_init (void)
 	max_zone_pfns[ZONE_DMA32] = max_dma;
 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 
-	virtual_map_init();
+	verify_gap_absence();
 
 	free_area_init(max_zone_pfns);
 	zero_page_memmap_ptr = virt_to_page(ia64_imva(empty_zero_page));
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index ef12e097f318453b257bef39642a3385e9e0526e..9b5acf8fb092c42ae93bbce929a91c2a5b0ccabb 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -574,20 +574,6 @@ ia64_pfn_valid (unsigned long pfn)
 }
 EXPORT_SYMBOL(ia64_pfn_valid);
 
-int __init find_largest_hole(u64 start, u64 end, void *arg)
-{
-	u64 *max_gap = arg;
-
-	static u64 last_end = PAGE_OFFSET;
-
-	/* NOTE: this algorithm assumes efi memmap table is ordered */
-
-	if (*max_gap < (start - last_end))
-		*max_gap = start - last_end;
-	last_end = end;
-	return 0;
-}
-
 #endif /* CONFIG_VIRTUAL_MEM_MAP */
 
 int __init register_active_ranges(u64 start, u64 len, int nid)