s390/page: Add memory clobber to page_set_storage_key()

Add memory clobbers to the page_set_storage_key() inline assemblies. This
allows for data dependencies from other code, which is important to prevent
the compiler from reordering instructions if required.

Note that this doesn't fix a bug in existing code; this is just a
prerequisite for upcoming code changes.

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index 79db884b8e3e5e2c50779cb39b94cb7f52efe403..843c5cba882fe02b53c6f26d6c4814ac2bde0980 100644 (file)
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -134,12 +134,14 @@ static inline void page_set_storage_key(unsigned long addr,
                asm volatile(
                        "       .insn   rrf,0xb22b0000,%[skey],%[addr],8,0"
                        :
-                       : [skey] "d" (skey), [addr] "a" (addr));
+                       : [skey] "d" (skey), [addr] "a" (addr)
+                       : "memory");
        } else {
                asm volatile(
                        "       sske     %[skey],%[addr]"
                        :
-                       : [skey] "d" (skey), [addr] "a" (addr));
+                       : [skey] "d" (skey), [addr] "a" (addr)
+                       : "memory");
        }
 }