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path: root/drivers/cpufreq/cpufreq.c
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Diffstat (limited to 'drivers/cpufreq/cpufreq.c')
-rw-r--r--drivers/cpufreq/cpufreq.c108
1 files changed, 55 insertions, 53 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 26063afb3eba..7a3c30c4336f 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -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;
}
@@ -1521,42 +1524,41 @@ static int __cpufreq_remove_dev_finish(struct device *dev,
static int 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 0;
+ if (!policy)
+ return 0;
- 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 0;
- }
+ cpumask_clear_cpu(cpu, policy->real_cpus);
+ if (cpumask_empty(policy->real_cpus)) {
cpufreq_policy_free(policy, true);
return 0;
}
- 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);
+
+ dev_dbg(dev, "%s: Moving policy object to CPU%u\n", __func__, new_cpu);
- if (!ret)
- ret = __cpufreq_remove_dev_finish(dev, sif);
+ sysfs_remove_link(&new_dev->kobj, "cpufreq");
+ policy->kobj_cpu = new_cpu;
+ WARN_ON(kobject_move(&policy->kobj, &new_dev->kobj));
+ }
- return ret;
+ return 0;
}
static void handle_update(struct work_struct *work)
@@ -2395,11 +2397,11 @@ 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: