1 files changed, 9 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 0321007086f7..8d4214afc21d 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -198,8 +198,15 @@ void smp_muxed_ipi_message_pass(int cpu, int msg)
         struct cpu_messages *info = &per_cpu(ipi_message, cpu);
         char *message = (char *)&info->messages;
 
+        /*
+         * Order previous accesses before accesses in the IPI handler.
+         */
+        smp_mb();
         message[msg] = 1;
-        mb();
+        /*
+         * cause_ipi functions are required to include a full barrier
+         * before doing whatever causes the IPI.
+         */
         smp_ops->cause_ipi(cpu, info->data);
 }
 
@@ -211,7 +218,7 @@ irqreturn_t smp_ipi_demux(void)
         mb();   /* order any irq clear */
 
         do {
-                all = xchg_local(&info->messages, 0);
+                all = xchg(&info->messages, 0);
 
 #ifdef __BIG_ENDIAN
                 if (all & (1 << (24 - 8 * PPC_MSG_CALL_FUNCTION)))