1 files changed, 21 insertions, 4 deletions

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 0321007086f7..2b952b5386fd 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -102,7 +102,7 @@ int __devinit smp_generic_kick_cpu(int nr)
 	 * Ok it's not there, so it might be soft-unplugged, let's
 	 * try to bring it back
 	 */
-	per_cpu(cpu_state, nr) = CPU_UP_PREPARE;
+	generic_set_cpu_up(nr);
 	smp_wmb();
 	smp_send_reschedule(nr);
 #endif /* CONFIG_HOTPLUG_CPU */
@@ -171,7 +171,7 @@ int smp_request_message_ipi(int virq, int msg)
 	}
 #endif
 	err = request_irq(virq, smp_ipi_action[msg],
-			  IRQF_PERCPU | IRQF_NO_THREAD,
+			  IRQF_PERCPU | IRQF_NO_THREAD | IRQF_NO_SUSPEND,
 			  smp_ipi_name[msg], 0);
 	WARN(err < 0, "unable to request_irq %d for %s (rc %d)\n",
 		virq, smp_ipi_name[msg], err);
@@ -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)))
@@ -406,6 +413,16 @@ void generic_set_cpu_dead(unsigned int cpu)
 	per_cpu(cpu_state, cpu) = CPU_DEAD;
 }
 
+/*
+ * The cpu_state should be set to CPU_UP_PREPARE in kick_cpu(), otherwise
+ * the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(),
+ * which makes the delay in generic_cpu_die() not happen.
+ */
+void generic_set_cpu_up(unsigned int cpu)
+{
+	per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
+}
+
 int generic_check_cpu_restart(unsigned int cpu)
 {
 	return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;