s390/pgtable: make pgste lock an explicit barrier

Getting and Releasing the pgste lock has lock semantics. Make the
code an explicit barrier.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index f9a0a70..e8b6e5b 100644 (file)
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -623,7 +623,7 @@ static inline pgste_t pgste_get_lock(pte_t *ptep)
                "       csg     %0,%1,%2\n"
                "       jl      0b\n"
                : "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])
-               : "Q" (ptep[PTRS_PER_PTE]) : "cc");
+               : "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory");
 #endif
        return __pgste(new);
 }
@@ -635,7 +635,8 @@ static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)
                "       nihh    %1,0xff7f\n"    /* clear RCP_PCL_BIT */
                "       stg     %1,%0\n"
                : "=Q" (ptep[PTRS_PER_PTE])
-               : "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE]) : "cc");
+               : "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE])
+               : "cc", "memory");
        preempt_enable();
 #endif
 }