[S390] 1K/2K page table pages.

This patch implements 1K/2K page table pages for s390.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/include/asm-s390/mmu_context.h b/include/asm-s390/mmu_context.h
index a77d4ba..3eaac5e 100644
--- a/include/asm-s390/mmu_context.h
+++ b/include/asm-s390/mmu_context.h
@@ -10,15 +10,17 @@
 #define __S390_MMU_CONTEXT_H
 
 #include <asm/pgalloc.h>
+#include <asm/uaccess.h>
 #include <asm-generic/mm_hooks.h>
 
 static inline int init_new_context(struct task_struct *tsk,
 				   struct mm_struct *mm)
 {
-	mm->context = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
+	mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
 #ifdef CONFIG_64BIT
-	mm->context |= _ASCE_TYPE_REGION3;
+	mm->context.asce_bits |= _ASCE_TYPE_REGION3;
 #endif
+	mm->context.noexec = s390_noexec;
 	return 0;
 }
 
@@ -32,11 +34,13 @@
 
 static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk)
 {
-	S390_lowcore.user_asce = mm->context | __pa(mm->pgd);
+	pgd_t *pgd = mm->pgd;
+
+	S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd);
 	if (switch_amode) {
 		/* Load primary space page table origin. */
-		pgd_t *shadow_pgd = get_shadow_table(mm->pgd) ? : mm->pgd;
-		S390_lowcore.user_exec_asce = mm->context | __pa(shadow_pgd);
+		pgd = mm->context.noexec ? get_shadow_table(pgd) : pgd;
+		S390_lowcore.user_exec_asce = mm->context.asce_bits | __pa(pgd);
 		asm volatile(LCTL_OPCODE" 1,1,%0\n"
 			     : : "m" (S390_lowcore.user_exec_asce) );
 	} else