diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 5caddd4f7bed..60a7b1a1702f 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -112,12 +112,15 @@ extern char empty_zero_page[PAGE_SIZE];
  * effect, this also makes sure that 64 bit module code cannot be used
  * as system call address.
  */
+
+extern unsigned long VMALLOC_START;
+
 #ifndef __s390x__
-#define VMALLOC_START	0x78000000UL
+#define VMALLOC_SIZE	(96UL << 20)
 #define VMALLOC_END	0x7e000000UL
 #define VMEM_MAP_END	0x80000000UL
 #else /* __s390x__ */
-#define VMALLOC_START	0x3e000000000UL
+#define VMALLOC_SIZE	(1UL << 30)
 #define VMALLOC_END	0x3e040000000UL
 #define VMEM_MAP_END	0x40000000000UL
 #endif /* __s390x__ */
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index be6c1cf4ad5a..4ca8e826bf30 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -1,7 +1,5 @@
 /*
- *  arch/s390/mm/pgtable.c
- *
- *    Copyright IBM Corp. 2007
+ *    Copyright IBM Corp. 2007,2009
  *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
  */
 
@@ -53,6 +51,18 @@ void clear_table_pgstes(unsigned long *table)
 
 #endif
 
+unsigned long VMALLOC_START = VMALLOC_END - VMALLOC_SIZE;
+EXPORT_SYMBOL(VMALLOC_START);
+
+static int __init parse_vmalloc(char *arg)
+{
+	if (!arg)
+		return -EINVAL;
+	VMALLOC_START = (VMALLOC_END - memparse(arg, &arg)) & PAGE_MASK;
+	return 0;
+}
+early_param("vmalloc", parse_vmalloc);
+
 unsigned long *crst_table_alloc(struct mm_struct *mm, int noexec)
 {
 	struct page *page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);