Merge tag 'driver-core-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git...
[cascardo/linux.git] / drivers / cpufreq / cpufreq.c
index 6da25c1..9bb09ce 100644 (file)
@@ -1002,7 +1002,7 @@ static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy)
        int ret = 0;
 
        /* Some related CPUs might not be present (physically hotplugged) */
-       for_each_cpu_and(j, policy->related_cpus, cpu_present_mask) {
+       for_each_cpu(j, policy->real_cpus) {
                if (j == policy->kobj_cpu)
                        continue;
 
@@ -1019,7 +1019,7 @@ 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_and(j, policy->related_cpus, cpu_present_mask) {
+       for_each_cpu(j, policy->real_cpus) {
                if (j == policy->kobj_cpu)
                        continue;
 
@@ -1163,11 +1163,14 @@ static struct cpufreq_policy *cpufreq_policy_alloc(struct device *dev)
        if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
                goto err_free_cpumask;
 
+       if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL))
+               goto err_free_rcpumask;
+
        ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, &dev->kobj,
                                   "cpufreq");
        if (ret) {
                pr_err("%s: failed to init policy->kobj: %d\n", __func__, ret);
-               goto err_free_rcpumask;
+               goto err_free_real_cpus;
        }
 
        INIT_LIST_HEAD(&policy->policy_list);
@@ -1184,6 +1187,8 @@ static struct cpufreq_policy *cpufreq_policy_alloc(struct device *dev)
 
        return policy;
 
+err_free_real_cpus:
+       free_cpumask_var(policy->real_cpus);
 err_free_rcpumask:
        free_cpumask_var(policy->related_cpus);
 err_free_cpumask:
@@ -1234,6 +1239,7 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy, bool notify)
        write_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
        cpufreq_policy_put_kobj(policy, notify);
+       free_cpumask_var(policy->real_cpus);
        free_cpumask_var(policy->related_cpus);
        free_cpumask_var(policy->cpus);
        kfree(policy);
@@ -1258,14 +1264,17 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
 
        pr_debug("adding CPU %u\n", cpu);
 
-       /*
-        * Only possible if 'cpu' wasn't physically present earlier and we are
-        * here from subsys_interface add callback. A hotplug notifier will
-        * follow and we will handle it like logical CPU hotplug then. For now,
-        * just create the sysfs link.
-        */
-       if (cpu_is_offline(cpu))
-               return add_cpu_dev_symlink(per_cpu(cpufreq_cpu_data, cpu), cpu);
+       if (cpu_is_offline(cpu)) {
+               /*
+                * Only possible if we are here from the subsys_interface add
+                * callback.  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.
+                */
+               policy = per_cpu(cpufreq_cpu_data, cpu);
+               return policy && !cpumask_test_and_set_cpu(cpu, policy->real_cpus)
+                       ? add_cpu_dev_symlink(policy, cpu) : 0;
+       }
 
        if (!down_read_trylock(&cpufreq_rwsem))
                return 0;
@@ -1307,6 +1316,10 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
        /* related cpus should atleast have policy->cpus */
        cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
 
+       /* Remember which CPUs have been present at the policy creation time. */
+       if (!recover_policy)
+               cpumask_and(policy->real_cpus, policy->cpus, cpu_present_mask);
+
        /*
         * affected cpus must always be the one, which are online. We aren't
         * managing offline cpus here.
@@ -1420,8 +1433,7 @@ nomem_out:
        return ret;
 }
 
-static int __cpufreq_remove_dev_prepare(struct device *dev,
-                                       struct subsys_interface *sif)
+static int __cpufreq_remove_dev_prepare(struct device *dev)
 {
        unsigned int cpu = dev->id;
        int ret = 0;
@@ -1437,10 +1449,8 @@ static int __cpufreq_remove_dev_prepare(struct device *dev,
 
        if (has_target()) {
                ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
-               if (ret) {
+               if (ret)
                        pr_err("%s: Failed to stop governor\n", __func__);
-                       return ret;
-               }
        }
 
        down_write(&policy->rwsem);
@@ -1473,8 +1483,7 @@ static int __cpufreq_remove_dev_prepare(struct device *dev,
        return ret;
 }
 
-static int __cpufreq_remove_dev_finish(struct device *dev,
-                                      struct subsys_interface *sif)
+static int __cpufreq_remove_dev_finish(struct device *dev)
 {
        unsigned int cpu = dev->id;
        int ret;
@@ -1492,10 +1501,8 @@ static int __cpufreq_remove_dev_finish(struct device *dev,
        /* If cpu is last user of policy, free policy */
        if (has_target()) {
                ret = __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
-               if (ret) {
+               if (ret)
                        pr_err("%s: Failed to exit governor\n", __func__);
-                       return ret;
-               }
        }
 
        /*
@@ -1506,10 +1513,6 @@ static int __cpufreq_remove_dev_finish(struct device *dev,
        if (cpufreq_driver->exit)
                cpufreq_driver->exit(policy);
 
-       /* Free the policy only if the driver is getting removed. */
-       if (sif)
-               cpufreq_policy_free(policy, true);
-
        return 0;
 }
 
@@ -1521,40 +1524,39 @@ static int __cpufreq_remove_dev_finish(struct device *dev,
 static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
 {
        unsigned int cpu = dev->id;
-       int ret;
-
-       /*
-        * Only possible if 'cpu' is getting physically removed now. A hotplug
-        * notifier should have already been called and we just need to remove
-        * link or free policy here.
-        */
-       if (cpu_is_offline(cpu)) {
-               struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
-               struct cpumask mask;
+       struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
 
-               if (!policy)
-                       return;
+       if (!policy)
+               return;
 
-               cpumask_copy(&mask, policy->related_cpus);
-               cpumask_clear_cpu(cpu, &mask);
+       if (cpu_online(cpu)) {
+               __cpufreq_remove_dev_prepare(dev);
+               __cpufreq_remove_dev_finish(dev);
+       }
 
-               /*
-                * Free policy only if all policy->related_cpus are removed
-                * physically.
-                */
-               if (cpumask_intersects(&mask, cpu_present_mask)) {
-                       remove_cpu_dev_symlink(policy, cpu);
-                       return;
-               }
+       cpumask_clear_cpu(cpu, policy->real_cpus);
 
+       if (cpumask_empty(policy->real_cpus)) {
                cpufreq_policy_free(policy, true);
                return;
        }
 
-       ret = __cpufreq_remove_dev_prepare(dev, sif);
+       if (cpu != policy->kobj_cpu) {
+               remove_cpu_dev_symlink(policy, cpu);
+       } else {
+               /*
+                * The CPU owning the policy object is going away.  Move it to
+                * another suitable CPU.
+                */
+               unsigned int new_cpu = cpumask_first(policy->real_cpus);
+               struct device *new_dev = get_cpu_device(new_cpu);
 
-       if (!ret)
-               __cpufreq_remove_dev_finish(dev, sif);
+               dev_dbg(dev, "%s: Moving policy object to CPU%u\n", __func__, new_cpu);
+
+               sysfs_remove_link(&new_dev->kobj, "cpufreq");
+               policy->kobj_cpu = new_cpu;
+               WARN_ON(kobject_move(&policy->kobj, &new_dev->kobj));
+       }
 }
 
 static void handle_update(struct work_struct *work)
@@ -2393,11 +2395,11 @@ static int cpufreq_cpu_callback(struct notifier_block *nfb,
                        break;
 
                case CPU_DOWN_PREPARE:
-                       __cpufreq_remove_dev_prepare(dev, NULL);
+                       __cpufreq_remove_dev_prepare(dev);
                        break;
 
                case CPU_POST_DEAD:
-                       __cpufreq_remove_dev_finish(dev, NULL);
+                       __cpufreq_remove_dev_finish(dev);
                        break;
 
                case CPU_DOWN_FAILED: