ARC: use ACCESS_ONCE in cmpxchg loop

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c
index 20ebb60..6a400b1 100644 (file)
--- a/arch/arc/kernel/smp.c
+++ b/arch/arc/kernel/smp.c
@@ -221,7 +221,7 @@ static void ipi_send_msg_one(int cpu, enum ipi_msg_type msg)
         * and read back old value
         */
        do {
-               new = old = *ipi_data_ptr;
+               new = old = ACCESS_ONCE(*ipi_data_ptr);
                new |= 1U << msg;
        } while (cmpxchg(ipi_data_ptr, old, new) != old);