@@ -175,6 +175,28 @@ static int powernv_cpuidle_driver_init(void)
drv->state_count += 1;
+ * On PowerNV platform cpu_present may be less that cpu_possible
+ * in cases where firmware detects the cpu, but it is not available
+ * for OS. Such CPUs are not hotplugable at runtime on PowerNV
+ * platform and hence sysfs files are not created for those.
+ * Generic topology_init() would skip creating sysfs directories
+ * for cpus that are not present and not hotplugable later at
+ * runtime.
+ * drv->cpumask defaults to cpu_possible_mask in __cpuidle_driver_init().
+ * This breaks cpuidle on powernv where sysfs files are not created for
+ * cpus in cpu_possible_mask that cannot be hot-added.
+ * Hence at runtime sysfs nodes are present for cpus only in
+ * cpu_present_mask. Trying cpuidle_register_device() on cpu without
+ * sysfs node is incorrect.
+ * Hence pass correct cpu mask to generic cpuidle driver.
+ drv->cpumask = (struct cpumask *)cpu_present_mask;