3 files changed, 20 insertions, 3 deletions

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 785229ae39cb..85cd4b039de6 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -38,6 +38,7 @@
 extern pgd_t swapper_pg_dir[] __attribute__ ((aligned (4096)));
 extern void paging_init(void);
 extern void vmem_map_init(void);
+extern void fault_init(void);
 
 /*
  * The S390 doesn't have any external MMU info: the kernel page
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 2505b2ea0ef1..b49d12073f10 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -52,6 +52,19 @@
 #define VM_FAULT_BADMAP         0x020000
 #define VM_FAULT_BADACCESS      0x040000
 
+static unsigned long store_indication;
+
+void fault_init(void)
+{
+        unsigned long long facility_list[2];
+
+        if (stfle(facility_list, 2) < 2)
+                return;
+        if ((facility_list[0] & (1ULL << 61)) &&
+            (facility_list[1] & (1ULL << 52)))
+                store_indication = 0xc00;
+}
+
 static inline int notify_page_fault(struct pt_regs *regs)
 {
         int ret = 0;
@@ -294,7 +307,7 @@ static inline int do_exception(struct pt_regs *regs, int access,
         struct mm_struct *mm;
         struct vm_area_struct *vma;
         unsigned long address;
-        int fault;
+        int fault, write;
 
         if (notify_page_fault(regs))
                 return 0;
@@ -348,8 +361,10 @@ static inline int do_exception(struct pt_regs *regs, int access,
          * make sure we exit gracefully rather than endlessly redo
          * the fault.
          */
-        fault = handle_mm_fault(mm, vma, address,
-                                (access == VM_WRITE) ? FAULT_FLAG_WRITE : 0);
+        write = (access == VM_WRITE ||
+                 (trans_exc_code & store_indication) == 0x400) ?
+                FAULT_FLAG_WRITE : 0;
+        fault = handle_mm_fault(mm, vma, address, write);
         if (unlikely(fault & VM_FAULT_ERROR))
                 goto out_up;
 
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 852a3fec1ece..bb409332a484 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -124,6 +124,7 @@ void __init paging_init(void)
 #endif
         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
         free_area_init_nodes(max_zone_pfns);
+        fault_init();
 }
 
 void __init mem_init(void)