From: Vineet Gupta <vgupta@synopsys.com>
Date: Mon, 15 Dec 2014 13:12:24 +0000 (+0530)
Subject: ARC: use ACCESS_ONCE in cmpxchg loop
X-Git-Tag: v4.0-rc1~78^2~4
X-Git-Url: https://git.kernelconcepts.de/?a=commitdiff_plain;h=7082a29c22ac0ab276b346f2a5c1d24a2102f158;p=karo-tx-linux.git

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 20ebb602ea2f..6a400b1b0b62 100644
--- 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);