1 files changed, 4 insertions, 37 deletions

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index c246d259822..5eb1ba74a3a 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -24,43 +24,6 @@
 
 #include "physaddr.h"
 
-int page_is_ram(unsigned long pagenr)
-{
-        resource_size_t addr, end;
-        int i;
-
-        /*
-         * A special case is the first 4Kb of memory;
-         * This is a BIOS owned area, not kernel ram, but generally
-         * not listed as such in the E820 table.
-         */
-        if (pagenr == 0)
-                return 0;
-
-        /*
-         * Second special case: Some BIOSen report the PC BIOS
-         * area (640->1Mb) as ram even though it is not.
-         */
-        if (pagenr >= (BIOS_BEGIN >> PAGE_SHIFT) &&
-                    pagenr < (BIOS_END >> PAGE_SHIFT))
-                return 0;
-
-        for (i = 0; i < e820.nr_map; i++) {
-                /*
-                 * Not usable memory:
-                 */
-                if (e820.map[i].type != E820_RAM)
-                        continue;
-                addr = (e820.map[i].addr + PAGE_SIZE-1) >> PAGE_SHIFT;
-                end = (e820.map[i].addr + e820.map[i].size) >> PAGE_SHIFT;
-
-
-                if ((pagenr >= addr) && (pagenr < end))
-                        return 1;
-        }
-        return 0;
-}
-
 /*
  * Fix up the linear direct mapping of the kernel to avoid cache attribute
  * conflicts.
@@ -422,6 +385,10 @@ void __init early_ioremap_init(void)
          * The boot-ioremap range spans multiple pmds, for which
          * we are not prepared:
          */
+#define __FIXADDR_TOP (-PAGE_SIZE)
+        BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
+                     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
+#undef __FIXADDR_TOP
         if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) {
                 WARN_ON(1);
                 printk(KERN_WARNING "pmd %p != %p\n",