summaryrefslogtreecommitdiff
path: root/drivers/cpufreq
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/cpufreq.c220
1 files changed, 135 insertions, 85 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 16214dfe78c5..4bfe0a53502f 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -957,28 +957,67 @@ void cpufreq_sysfs_remove_file(const struct attribute *attr)
}
EXPORT_SYMBOL(cpufreq_sysfs_remove_file);
-/* symlink affected CPUs */
+static int add_cpu_dev_symlink(struct cpufreq_policy *policy, int cpu)
+{
+ 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");
+}
+
+/* Add/remove symlinks for all related CPUs */
static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy)
{
unsigned int j;
int ret = 0;
- for_each_cpu(j, policy->cpus) {
- struct device *cpu_dev;
-
+ /* Some related CPUs might not be present (physically hotplugged) */
+ for_each_cpu_and(j, policy->related_cpus, cpu_present_mask) {
if (j == policy->kobj_cpu)
continue;
- pr_debug("Adding link for CPU: %u\n", j);
- cpu_dev = get_cpu_device(j);
- ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj,
- "cpufreq");
+ 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_and(j, policy->related_cpus, cpu_present_mask) {
+ if (j == policy->kobj_cpu)
+ continue;
+
+ remove_cpu_dev_symlink(policy, j);
+ }
+}
+
static int cpufreq_add_dev_interface(struct cpufreq_policy *policy,
struct device *dev)
{
@@ -1075,7 +1114,7 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy,
}
}
- return sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq");
+ return 0;
}
static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu)
@@ -1095,7 +1134,7 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu)
return policy;
}
-static struct cpufreq_policy *cpufreq_policy_alloc(void)
+static struct cpufreq_policy *cpufreq_policy_alloc(int cpu)
{
struct cpufreq_policy *policy;
@@ -1116,6 +1155,11 @@ static struct cpufreq_policy *cpufreq_policy_alloc(void)
init_completion(&policy->kobj_unregister);
INIT_WORK(&policy->update, handle_update);
+ policy->cpu = cpu;
+
+ /* Set this once on allocation */
+ policy->kobj_cpu = cpu;
+
return policy;
err_free_cpumask:
@@ -1134,10 +1178,11 @@ static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
CPUFREQ_REMOVE_POLICY, policy);
- down_read(&policy->rwsem);
+ down_write(&policy->rwsem);
+ cpufreq_remove_dev_symlink(policy);
kobj = &policy->kobj;
cmp = &policy->kobj_unregister;
- up_read(&policy->rwsem);
+ up_write(&policy->rwsem);
kobject_put(kobj);
/*
@@ -1168,27 +1213,14 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy)
kfree(policy);
}
-static int update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu,
- struct device *cpu_dev)
+static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
{
- int ret;
-
if (WARN_ON(cpu == policy->cpu))
- return 0;
-
- /* Move kobject to the new policy->cpu */
- ret = kobject_move(&policy->kobj, &cpu_dev->kobj);
- if (ret) {
- pr_err("%s: Failed to move kobj: %d\n", __func__, ret);
- return ret;
- }
+ return;
down_write(&policy->rwsem);
policy->cpu = cpu;
- policy->kobj_cpu = cpu;
up_write(&policy->rwsem);
-
- return 0;
}
/**
@@ -1206,13 +1238,19 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
int ret = -ENOMEM;
struct cpufreq_policy *policy;
unsigned long flags;
- bool recover_policy = cpufreq_suspended;
-
- if (cpu_is_offline(cpu))
- return 0;
+ bool recover_policy = !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 (!down_read_trylock(&cpufreq_rwsem))
return 0;
@@ -1232,7 +1270,7 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
policy = recover_policy ? cpufreq_policy_restore(cpu) : NULL;
if (!policy) {
recover_policy = false;
- policy = cpufreq_policy_alloc();
+ policy = cpufreq_policy_alloc(cpu);
if (!policy)
goto nomem_out;
}
@@ -1243,12 +1281,8 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
* the creation of a brand new one. So we need to perform this update
* by invoking update_policy_cpu().
*/
- if (recover_policy && cpu != policy->cpu) {
- WARN_ON(update_policy_cpu(policy, cpu, dev));
- } else {
- policy->cpu = cpu;
- policy->kobj_cpu = cpu;
- }
+ if (recover_policy && cpu != policy->cpu)
+ update_policy_cpu(policy, cpu);
cpumask_copy(policy->cpus, cpumask_of(cpu));
@@ -1427,29 +1461,14 @@ static int __cpufreq_remove_dev_prepare(struct device *dev,
CPUFREQ_NAME_LEN);
up_write(&policy->rwsem);
- if (cpu != policy->kobj_cpu) {
- sysfs_remove_link(&dev->kobj, "cpufreq");
- } else if (cpus > 1) {
- /* Nominate new CPU */
- int new_cpu = cpumask_any_but(policy->cpus, cpu);
- struct device *cpu_dev = get_cpu_device(new_cpu);
-
- sysfs_remove_link(&cpu_dev->kobj, "cpufreq");
- ret = update_policy_cpu(policy, new_cpu, cpu_dev);
- if (ret) {
- if (sysfs_create_link(&cpu_dev->kobj, &policy->kobj,
- "cpufreq"))
- pr_err("%s: Failed to restore kobj link to cpu:%d\n",
- __func__, cpu_dev->id);
- return ret;
- }
+ if (cpu != policy->cpu)
+ return 0;
- if (!cpufreq_suspended)
- pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n",
- __func__, new_cpu, cpu);
- } else if (cpufreq_driver->stop_cpu) {
+ if (cpus > 1)
+ /* Nominate new CPU */
+ update_policy_cpu(policy, cpumask_any_but(policy->cpus, cpu));
+ else if (cpufreq_driver->stop_cpu)
cpufreq_driver->stop_cpu(policy);
- }
return 0;
}
@@ -1470,32 +1489,11 @@ static int __cpufreq_remove_dev_finish(struct device *dev,
cpumask_clear_cpu(cpu, policy->cpus);
up_write(&policy->rwsem);
- /* If cpu is last user of policy, free policy */
- if (policy_is_inactive(policy)) {
- if (has_target()) {
- ret = __cpufreq_governor(policy,
- CPUFREQ_GOV_POLICY_EXIT);
- if (ret) {
- pr_err("%s: Failed to exit governor\n",
- __func__);
- return ret;
- }
- }
-
- if (!cpufreq_suspended)
- cpufreq_policy_put_kobj(policy);
+ /* Not the last cpu of policy, start governor again ? */
+ if (!policy_is_inactive(policy)) {
+ if (!has_target())
+ return 0;
- /*
- * Perform the ->exit() even during light-weight tear-down,
- * since this is a core component, and is essential for the
- * subsequent light-weight ->init() to succeed.
- */
- if (cpufreq_driver->exit)
- cpufreq_driver->exit(policy);
-
- if (!cpufreq_suspended)
- cpufreq_policy_free(policy);
- } else if (has_target()) {
ret = __cpufreq_governor(policy, CPUFREQ_GOV_START);
if (!ret)
ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
@@ -1504,8 +1502,34 @@ static int __cpufreq_remove_dev_finish(struct device *dev,
pr_err("%s: Failed to start governor\n", __func__);
return ret;
}
+
+ return 0;
}
+ /* If cpu is last user of policy, free policy */
+ if (has_target()) {
+ ret = __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
+ if (ret) {
+ pr_err("%s: Failed to exit governor\n", __func__);
+ return ret;
+ }
+ }
+
+ /* Free the policy kobjects only if the driver is getting removed. */
+ if (sif)
+ cpufreq_policy_put_kobj(policy);
+
+ /*
+ * Perform the ->exit() even during light-weight tear-down,
+ * since this is a core component, and is essential for the
+ * subsequent light-weight ->init() to succeed.
+ */
+ if (cpufreq_driver->exit)
+ cpufreq_driver->exit(policy);
+
+ if (sif)
+ cpufreq_policy_free(policy);
+
return 0;
}
@@ -1519,8 +1543,34 @@ static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
unsigned int cpu = dev->id;
int ret;
- if (cpu_is_offline(cpu))
+ /*
+ * 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;
+
+ if (!policy)
+ return 0;
+
+ cpumask_copy(&mask, policy->related_cpus);
+ cpumask_clear_cpu(cpu, &mask);
+
+ /*
+ * 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;
+ }
+
+ cpufreq_policy_put_kobj(policy);
+ cpufreq_policy_free(policy);
return 0;
+ }
ret = __cpufreq_remove_dev_prepare(dev, sif);
generated by cgit v1.2.3 (git 2.39.0) at 2024-10-31 12:24:16 +0300