2 files changed, 39 insertions, 17 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 5dbdd261aa73..bc96d423781a 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -918,11 +918,19 @@ static struct kobj_type ktype_cpufreq = {
 	.release	= cpufreq_sysfs_release,
 };
 
-static int add_cpu_dev_symlink(struct cpufreq_policy *policy,
-			       struct device *dev)
+static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu)
 {
+	struct device *dev = get_cpu_device(cpu);
+
+	if (!dev)
+		return;
+
+	if (cpumask_test_and_set_cpu(cpu, policy->real_cpus))
+		return;
+
 	dev_dbg(dev, "%s: Adding symlink\n", __func__);
-	return sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq");
+	if (sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"))
+		dev_err(dev, "cpufreq symlink creation failed\n");
 }
 
 static void remove_cpu_dev_symlink(struct cpufreq_policy *policy,
@@ -1180,10 +1188,10 @@ static int cpufreq_online(unsigned int cpu)
 		policy->user_policy.min = policy->min;
 		policy->user_policy.max = policy->max;
 
-		write_lock_irqsave(&cpufreq_driver_lock, flags);
-		for_each_cpu(j, policy->related_cpus)
+		for_each_cpu(j, policy->related_cpus) {
 			per_cpu(cpufreq_cpu_data, j) = policy;
-		write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+			add_cpu_dev_symlink(policy, j);
+		}
 	} else {
 		policy->min = policy->user_policy.min;
 		policy->max = policy->user_policy.max;
@@ -1275,13 +1283,15 @@ out_exit_policy:
 
 	if (cpufreq_driver->exit)
 		cpufreq_driver->exit(policy);
+
+	for_each_cpu(j, policy->real_cpus)
+		remove_cpu_dev_symlink(policy, get_cpu_device(j));
+
 out_free_policy:
 	cpufreq_policy_free(policy);
 	return ret;
 }
 
-static int cpufreq_offline(unsigned int cpu);
-
 /**
  * cpufreq_add_dev - the cpufreq interface for a CPU device.
  * @dev: CPU device.
@@ -1303,16 +1313,10 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
 
 	/* Create sysfs link on CPU registration */
 	policy = per_cpu(cpufreq_cpu_data, cpu);
-	if (!policy || cpumask_test_and_set_cpu(cpu, policy->real_cpus))
-		return 0;
+	if (policy)
+		add_cpu_dev_symlink(policy, cpu);
 
-	ret = add_cpu_dev_symlink(policy, dev);
-	if (ret) {
-		cpumask_clear_cpu(cpu, policy->real_cpus);
-		cpufreq_offline(cpu);
-	}
-
-	return ret;
+	return 0;
 }
 
 static int cpufreq_offline(unsigned int cpu)
diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index 370593006f5f..cda8f62d555b 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -175,6 +175,24 @@ static int powernv_cpuidle_driver_init(void)
 		drv->state_count += 1;
 	}
 
+	/*
+	 * On the PowerNV platform cpu_present may be less than cpu_possible in
+	 * cases when firmware detects the CPU, but it is not available to the
+	 * OS.  If CONFIG_HOTPLUG_CPU=n, then such CPUs are not hotplugable at
+	 * run time and hence cpu_devices are not created for those CPUs by the
+	 * generic topology_init().
+	 *
+	 * drv->cpumask defaults to cpu_possible_mask in
+	 * __cpuidle_driver_init().  This breaks cpuidle on PowerNV where
+	 * cpu_devices are not created for CPUs in cpu_possible_mask that
+	 * cannot be hot-added later at run time.
+	 *
+	 * Trying cpuidle_register_device() on a CPU without a cpu_device is
+	 * incorrect, so pass a correct CPU mask to the generic cpuidle driver.
+	 */
+
+	drv->cpumask = (struct cpumask *)cpu_present_mask;
+
 	return 0;
 }