x86: move devmem_is_allowed() to common mm/init.c

Impact: cleanup

The function is identical on 32-bit and 64-bit configurations so move
it to the common mm/init.c file.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <1236160001.29024.29.camel@penberg-laptop>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/mm/init.c

+#include <linux/ioport.h>
 #include <linux/swap.h>
+
 #include <asm/cacheflush.h>
 #include <asm/page.h>
+#include <asm/page_types.h>
 #include <asm/sections.h>
 #include <asm/system.h>
 
+/*
+ * devmem_is_allowed() checks to see if /dev/mem access to a certain address
+ * is valid. The argument is a physical page number.
+ *
+ *
+ * On x86, access has to be given to the first megabyte of ram because that area
+ * contains bios code and data regions used by X and dosemu and similar apps.
+ * Access has to be given to non-kernel-ram areas as well, these contain the PCI
+ * mmio resources as well as potential bios/acpi data regions.
+ */
+int devmem_is_allowed(unsigned long pagenr)
+{
+	if (pagenr <= 256)
+		return 1;
+	if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
+		return 0;
+	if (!page_is_ram(pagenr))
+		return 1;
+	return 0;
+}
+
 void free_init_pages(char *what, unsigned long begin, unsigned long end)
 {
 	unsigned long addr = begin;

arch/x86/mm/init_32.c

@@ -354,27 +354,6 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base,
 	}
 }
 
-/*
- * devmem_is_allowed() checks to see if /dev/mem access to a certain address
- * is valid. The argument is a physical page number.
- *
- *
- * On x86, access has to be given to the first megabyte of ram because that area
- * contains bios code and data regions used by X and dosemu and similar apps.
- * Access has to be given to non-kernel-ram areas as well, these contain the PCI
- * mmio resources as well as potential bios/acpi data regions.
- */
-int devmem_is_allowed(unsigned long pagenr)
-{
-	if (pagenr <= 256)
-		return 1;
-	if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
-		return 0;
-	if (!page_is_ram(pagenr))
-		return 1;
-	return 0;
-}
-
 pte_t *kmap_pte;
 pgprot_t kmap_prot;
 

arch/x86/mm/init_64.c

@@ -876,28 +876,6 @@ EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 
 #endif /* CONFIG_MEMORY_HOTPLUG */
 
-/*
- * devmem_is_allowed() checks to see if /dev/mem access to a certain address
- * is valid. The argument is a physical page number.
- *
- *
- * On x86, access has to be given to the first megabyte of ram because that area
- * contains bios code and data regions used by X and dosemu and similar apps.
- * Access has to be given to non-kernel-ram areas as well, these contain the PCI
- * mmio resources as well as potential bios/acpi data regions.
- */
-int devmem_is_allowed(unsigned long pagenr)
-{
-	if (pagenr <= 256)
-		return 1;
-	if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
-		return 0;
-	if (!page_is_ram(pagenr))
-		return 1;
-	return 0;
-}
-
-
 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
 			 kcore_modules, kcore_vsyscall;