1 files changed, 49 insertions, 27 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 0611ae48e767..1d041aff4d48 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -903,7 +903,7 @@ static void cpufreq_init_policy(struct cpufreq_policy *policy)
 
 #ifdef CONFIG_HOTPLUG_CPU
 static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling,
-                                  struct device *dev)
+                                  struct device *dev, bool frozen)
 {
         struct cpufreq_policy *policy;
         int ret = 0, has_target = !!cpufreq_driver->target;
@@ -931,13 +931,18 @@ static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling,
                 __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
         }
 
-        ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq");
-        if (ret) {
+        /* Don't touch sysfs links during light-weight init */
+        if (frozen) {
+                /* Drop the extra refcount that we took above */
                 cpufreq_cpu_put(policy);
-                return ret;
+                return 0;
         }
 
-        return 0;
+        ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq");
+        if (ret)
+                cpufreq_cpu_put(policy);
+
+        return ret;
 }
 #endif
 
@@ -972,16 +977,8 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy)
         kfree(policy);
 }
 
-/**
- * cpufreq_add_dev - add a CPU device
- *
- * Adds the cpufreq interface for a CPU device.
- *
- * The Oracle says: try running cpufreq registration/unregistration concurrently
- * with with cpu hotplugging and all hell will break loose. Tried to clean this
- * mess up, but more thorough testing is needed. - Mathieu
- */
-static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
+static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
+                             bool frozen)
 {
         unsigned int j, cpu = dev->id;
         int ret = -ENOMEM;
@@ -1013,7 +1010,8 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
                 struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling);
                 if (cp && cpumask_test_cpu(cpu, cp->related_cpus)) {
                         read_unlock_irqrestore(&cpufreq_driver_lock, flags);
-                        return cpufreq_add_policy_cpu(cpu, sibling, dev);
+                        return cpufreq_add_policy_cpu(cpu, sibling, dev,
+                                                      frozen);
                 }
         }
         read_unlock_irqrestore(&cpufreq_driver_lock, flags);
@@ -1079,9 +1077,11 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
         }
         write_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
-        ret = cpufreq_add_dev_interface(cpu, policy, dev);
-        if (ret)
-                goto err_out_unregister;
+        if (!frozen) {
+                ret = cpufreq_add_dev_interface(cpu, policy, dev);
+                if (ret)
+                        goto err_out_unregister;
+        }
 
         cpufreq_init_policy(policy);
 
@@ -1112,6 +1112,20 @@ module_out:
         return ret;
 }
 
+/**
+ * cpufreq_add_dev - add a CPU device
+ *
+ * Adds the cpufreq interface for a CPU device.
+ *
+ * The Oracle says: try running cpufreq registration/unregistration concurrently
+ * with with cpu hotplugging and all hell will break loose. Tried to clean this
+ * mess up, but more thorough testing is needed. - Mathieu
+ */
+static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
+{
+        return __cpufreq_add_dev(dev, sif, false);
+}
+
 static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
 {
         int j;
@@ -1130,7 +1144,7 @@ static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
 }
 
 static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *data,
-                                           unsigned int old_cpu)
+                                           unsigned int old_cpu, bool frozen)
 {
         struct device *cpu_dev;
         unsigned long flags;
@@ -1138,6 +1152,11 @@ static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *data,
 
         /* first sibling now owns the new sysfs dir */
         cpu_dev = get_cpu_device(cpumask_first(data->cpus));
+
+        /* Don't touch sysfs files during light-weight tear-down */
+        if (frozen)
+                return cpu_dev->id;
+
         sysfs_remove_link(&cpu_dev->kobj, "cpufreq");
         ret = kobject_move(&data->kobj, &cpu_dev->kobj);
         if (ret) {
@@ -1169,7 +1188,7 @@ static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *data,
  * This routine frees the rwsem before returning.
  */
 static int __cpufreq_remove_dev(struct device *dev,
-                struct subsys_interface *sif)
+                                struct subsys_interface *sif, bool frozen)
 {
         unsigned int cpu = dev->id, cpus;
         int new_cpu;
@@ -1208,17 +1227,20 @@ static int __cpufreq_remove_dev(struct device *dev,
                 cpumask_clear_cpu(cpu, data->cpus);
         unlock_policy_rwsem_write(cpu);
 
-        if (cpu != data->cpu) {
+        if (cpu != data->cpu && !frozen) {
                 sysfs_remove_link(&dev->kobj, "cpufreq");
         } else if (cpus > 1) {
 
-                new_cpu = cpufreq_nominate_new_policy_cpu(data, cpu);
+                new_cpu = cpufreq_nominate_new_policy_cpu(data, cpu, frozen);
                 if (new_cpu >= 0) {
                         WARN_ON(lock_policy_rwsem_write(cpu));
                         update_policy_cpu(data, new_cpu);
                         unlock_policy_rwsem_write(cpu);
-                        pr_debug("%s: policy Kobject moved to cpu: %d "
-                                 "from: %d\n",__func__, new_cpu, cpu);
+
+                        if (!frozen) {
+                                pr_debug("%s: policy Kobject moved to cpu: %d "
+                                         "from: %d\n",__func__, new_cpu, cpu);
+                        }
                 }
         }
 
@@ -1266,7 +1288,7 @@ static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
         if (cpu_is_offline(cpu))
                 return 0;
 
-        retval = __cpufreq_remove_dev(dev, sif);
+        retval = __cpufreq_remove_dev(dev, sif, false);
         return retval;
 }
 
@@ -1992,7 +2014,7 @@ static int cpufreq_cpu_callback(struct notifier_block *nfb,
                         break;
                 case CPU_DOWN_PREPARE:
                 case CPU_DOWN_PREPARE_FROZEN:
-                        __cpufreq_remove_dev(dev, NULL);
+                        __cpufreq_remove_dev(dev, NULL, false);
                         break;
                 case CPU_DOWN_FAILED:
                 case CPU_DOWN_FAILED_FROZEN: