diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index 34b6f6ab4742..657bdee28d84 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -565,7 +565,8 @@ Description:	Control Symmetric Multi Threading (SMT)
 			 ================ =========================================
 
 			 If control status is "forceoff" or "notsupported" writes
-			 are rejected.
+			 are rejected. Note that enabling SMT on PowerPC skips
+			 offline cores.
 
 What:		/sys/devices/system/cpu/cpuX/power/energy_perf_bias
 Date:		March 2019
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 874bfb952e6e..0c72b94ed076 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -2728,6 +2728,16 @@ int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
 	return ret;
 }
 
+/**
+ * Check if the core a CPU belongs to is online
+ */
+#if !defined(topology_is_core_online)
+static inline bool topology_is_core_online(unsigned int cpu)
+{
+	return true;
+}
+#endif
+
 int cpuhp_smt_enable(void)
 {
 	int cpu, ret = 0;
@@ -2738,7 +2748,7 @@ int cpuhp_smt_enable(void)
 		/* Skip online CPUs and CPUs on offline nodes */
 		if (cpu_online(cpu) || !node_online(cpu_to_node(cpu)))
 			continue;
-		if (!cpu_smt_thread_allowed(cpu))
+		if (!cpu_smt_thread_allowed(cpu) || !topology_is_core_online(cpu))
 			continue;
 		ret = _cpu_up(cpu, 0, CPUHP_ONLINE);
 		if (ret)