Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[cascardo/linux.git] / drivers / cpufreq / cpufreq.c

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 8b44de4..6e6c1fb 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -916,58 +916,18 @@ static struct kobj_type ktype_cpufreq = {
        .release        = cpufreq_sysfs_release,
 };
 
-static int add_cpu_dev_symlink(struct cpufreq_policy *policy, int cpu)
+static int add_cpu_dev_symlink(struct cpufreq_policy *policy,
+                              struct device *dev)
 {
-       struct device *cpu_dev;
-
-       pr_debug("%s: Adding symlink for CPU: %u\n", __func__, cpu);
-
-       if (!policy)
-               return 0;
-
-       cpu_dev = get_cpu_device(cpu);
-       if (WARN_ON(!cpu_dev))
-               return 0;
-
-       return sysfs_create_link(&cpu_dev->kobj, &policy->kobj, "cpufreq");
-}
-
-static void remove_cpu_dev_symlink(struct cpufreq_policy *policy, int cpu)
-{
-       struct device *cpu_dev;
-
-       pr_debug("%s: Removing symlink for CPU: %u\n", __func__, cpu);
-
-       cpu_dev = get_cpu_device(cpu);
-       if (WARN_ON(!cpu_dev))
-               return;
-
-       sysfs_remove_link(&cpu_dev->kobj, "cpufreq");
+       dev_dbg(dev, "%s: Adding symlink\n", __func__);
+       return sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq");
 }
 
-/* Add/remove symlinks for all related CPUs */
-static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy)
+static void remove_cpu_dev_symlink(struct cpufreq_policy *policy,
+                                  struct device *dev)
 {
-       unsigned int j;
-       int ret = 0;
-
-       /* Some related CPUs might not be present (physically hotplugged) */
-       for_each_cpu(j, policy->real_cpus) {
-               ret = add_cpu_dev_symlink(policy, j);
-               if (ret)
-                       break;
-       }
-
-       return ret;
-}
-
-static void cpufreq_remove_dev_symlink(struct cpufreq_policy *policy)
-{
-       unsigned int j;
-
-       /* Some related CPUs might not be present (physically hotplugged) */
-       for_each_cpu(j, policy->real_cpus)
-               remove_cpu_dev_symlink(policy, j);
+       dev_dbg(dev, "%s: Removing symlink\n", __func__);
+       sysfs_remove_link(&dev->kobj, "cpufreq");
 }
 
 static int cpufreq_add_dev_interface(struct cpufreq_policy *policy)
@@ -999,7 +959,7 @@ static int cpufreq_add_dev_interface(struct cpufreq_policy *policy)
                        return ret;
        }
 
-       return cpufreq_add_dev_symlink(policy);
+       return 0;
 }
 
 __weak struct cpufreq_governor *cpufreq_default_governor(void)
@@ -1073,13 +1033,9 @@ static void handle_update(struct work_struct *work)
 
 static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
 {
-       struct device *dev = get_cpu_device(cpu);
        struct cpufreq_policy *policy;
        int ret;
 
-       if (WARN_ON(!dev))
-               return NULL;
-
        policy = kzalloc(sizeof(*policy), GFP_KERNEL);
        if (!policy)
                return NULL;
@@ -1133,7 +1089,6 @@ static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy, bool notify)
 
        down_write(&policy->rwsem);
        cpufreq_stats_free_table(policy);
-       cpufreq_remove_dev_symlink(policy);
        kobj = &policy->kobj;
        cmp = &policy->kobj_unregister;
        up_write(&policy->rwsem);
@@ -1215,8 +1170,8 @@ static int cpufreq_online(unsigned int cpu)
        if (new_policy) {
                /* related_cpus should at least include policy->cpus. */
                cpumask_copy(policy->related_cpus, policy->cpus);
-               /* Remember CPUs present at the policy creation time. */
-               cpumask_and(policy->real_cpus, policy->cpus, cpu_present_mask);
+               /* Clear mask of registered CPUs */
+               cpumask_clear(policy->real_cpus);
        }
 
        /*
@@ -1331,6 +1286,8 @@ out_free_policy:
        return ret;
 }
 
+static int cpufreq_offline(unsigned int cpu);
+
 /**
  * cpufreq_add_dev - the cpufreq interface for a CPU device.
  * @dev: CPU device.
@@ -1340,22 +1297,28 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
 {
        struct cpufreq_policy *policy;
        unsigned cpu = dev->id;
+       int ret;
 
        dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu);
 
-       if (cpu_online(cpu))
-               return cpufreq_online(cpu);
+       if (cpu_online(cpu)) {
+               ret = cpufreq_online(cpu);
+               if (ret)
+                       return ret;
+       }
 
-       /*
-        * A hotplug notifier will follow and we will handle it as CPU online
-        * then.  For now, just create the sysfs link, unless there is no policy
-        * or the link is already present.
-        */
+       /* 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;
 
-       return 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;
 }
 
 static int cpufreq_offline(unsigned int cpu)
@@ -1437,7 +1400,7 @@ static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
                cpufreq_offline(cpu);
 
        cpumask_clear_cpu(cpu, policy->real_cpus);
-       remove_cpu_dev_symlink(policy, cpu);
+       remove_cpu_dev_symlink(policy, dev);
 
        if (cpumask_empty(policy->real_cpus))
                cpufreq_policy_free(policy, true);