diff options
| -rw-r--r-- | arch/arc/include/asm/cmpxchg.h | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/arc/include/asm/cmpxchg.h b/arch/arc/include/asm/cmpxchg.h index 03cd6894855d..90de5c528da2 100644 --- a/arch/arc/include/asm/cmpxchg.h +++ b/arch/arc/include/asm/cmpxchg.h @@ -25,10 +25,11 @@ __cmpxchg(volatile void *ptr, unsigned long expected, unsigned long new) " scond %3, [%1] \n" " bnz 1b \n" "2: \n" - : "=&r"(prev) - : "r"(ptr), "ir"(expected), - "r"(new) /* can't be "ir". scond can't take limm for "b" */ - : "cc"); + : "=&r"(prev) /* Early clobber, to prevent reg reuse */ + : "r"(ptr), /* Not "m": llock only supports reg direct addr mode */ + "ir"(expected), + "r"(new) /* can't be "ir". scond can't take LIMM for "b" */ + : "cc", "memory"); /* so that gcc knows memory is being written here */ return prev; } |