* are concerned with are online after they get the lock.
* - Governor routines that can be called in cpufreq hotplug path should not
* take this sem as top level hotplug notifier handler takes this.
+ * - Lock should not be held across
+ * __cpufreq_governor(data, CPUFREQ_GOV_STOP);
*/
static DEFINE_PER_CPU(int, policy_cpu);
static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem);
NULL
};
+struct kobject *cpufreq_global_kobject;
+EXPORT_SYMBOL(cpufreq_global_kobject);
+
#define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
#define to_attr(a) container_of(a, struct freq_attr, attr)
.release = cpufreq_sysfs_release,
};
-
-/**
- * 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
+/*
+ * Returns:
+ * Negative: Failure
+ * 0: Success
+ * Positive: When we have a managed CPU and the sysfs got symlinked
*/
-static int cpufreq_add_dev(struct sys_device *sys_dev)
+int cpufreq_add_dev_policy(unsigned int cpu, struct cpufreq_policy *policy,
+ struct sys_device *sys_dev)
{
- unsigned int cpu = sys_dev->id;
int ret = 0;
- struct cpufreq_policy new_policy;
- struct cpufreq_policy *policy;
- struct freq_attr **drv_attr;
- struct sys_device *cpu_sys_dev;
+#ifdef CONFIG_SMP
unsigned long flags;
unsigned int j;
- if (cpu_is_offline(cpu))
- return 0;
-
- cpufreq_debug_disable_ratelimit();
- dprintk("adding CPU %u\n", cpu);
-
-#ifdef CONFIG_SMP
- /* check whether a different CPU already registered this
- * CPU because it is in the same boat. */
- policy = cpufreq_cpu_get(cpu);
- if (unlikely(policy)) {
- cpufreq_cpu_put(policy);
- cpufreq_debug_enable_ratelimit();
- return 0;
- }
-#endif
-
- if (!try_module_get(cpufreq_driver->owner)) {
- ret = -EINVAL;
- goto module_out;
- }
-
- policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL);
- if (!policy) {
- ret = -ENOMEM;
- goto nomem_out;
- }
- if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) {
- ret = -ENOMEM;
- goto err_free_policy;
- }
- if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) {
- ret = -ENOMEM;
- goto err_free_cpumask;
- }
-
- policy->cpu = cpu;
- cpumask_copy(policy->cpus, cpumask_of(cpu));
-
- /* Initially set CPU itself as the policy_cpu */
- per_cpu(policy_cpu, cpu) = cpu;
- ret = (lock_policy_rwsem_write(cpu) < 0);
- WARN_ON(ret);
-
- init_completion(&policy->kobj_unregister);
- INIT_WORK(&policy->update, handle_update);
-
- /* Set governor before ->init, so that driver could check it */
- policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
- /* call driver. From then on the cpufreq must be able
- * to accept all calls to ->verify and ->setpolicy for this CPU
- */
- ret = cpufreq_driver->init(policy);
- if (ret) {
- dprintk("initialization failed\n");
- goto err_unlock_policy;
- }
- policy->user_policy.min = policy->min;
- policy->user_policy.max = policy->max;
-
- blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
- CPUFREQ_START, policy);
-
-#ifdef CONFIG_SMP
-
#ifdef CONFIG_HOTPLUG_CPU
if (per_cpu(cpufreq_cpu_governor, cpu)) {
policy->governor = per_cpu(cpufreq_cpu_governor, cpu);
/* Should not go through policy unlock path */
if (cpufreq_driver->exit)
cpufreq_driver->exit(policy);
- ret = -EBUSY;
cpufreq_cpu_put(managed_policy);
- goto err_free_cpumask;
+ return -EBUSY;
}
spin_lock_irqsave(&cpufreq_driver_lock, flags);
* Call driver->exit() because only the cpu parent of
* the kobj needed to call init().
*/
- goto out_driver_exit; /* call driver->exit() */
+ if (cpufreq_driver->exit)
+ cpufreq_driver->exit(policy);
+
+ if (!ret)
+ return 1;
+ else
+ return ret;
}
}
#endif
- memcpy(&new_policy, policy, sizeof(struct cpufreq_policy));
+ return ret;
+}
+
+
+/* symlink affected CPUs */
+int cpufreq_add_dev_symlink(unsigned int cpu, struct cpufreq_policy *policy)
+{
+ unsigned int j;
+ int ret = 0;
+
+ for_each_cpu(j, policy->cpus) {
+ struct cpufreq_policy *managed_policy;
+ struct sys_device *cpu_sys_dev;
+
+ if (j == cpu)
+ continue;
+ if (!cpu_online(j))
+ continue;
+
+ dprintk("CPU %u already managed, adding link\n", j);
+ managed_policy = cpufreq_cpu_get(cpu);
+ cpu_sys_dev = get_cpu_sysdev(j);
+ ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj,
+ "cpufreq");
+ if (ret) {
+ cpufreq_cpu_put(managed_policy);
+ return ret;
+ }
+ }
+ return ret;
+}
+
+int cpufreq_add_dev_interface(unsigned int cpu, struct cpufreq_policy *policy,
+ struct sys_device *sys_dev)
+{
+ struct cpufreq_policy new_policy;
+ struct freq_attr **drv_attr;
+ unsigned long flags;
+ int ret = 0;
+ unsigned int j;
/* prepare interface data */
- ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, &sys_dev->kobj,
- "cpufreq");
+ ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
+ &sys_dev->kobj, "cpufreq");
if (ret)
- goto out_driver_exit;
+ return ret;
/* set up files for this cpu device */
drv_attr = cpufreq_driver->attr;
spin_lock_irqsave(&cpufreq_driver_lock, flags);
for_each_cpu(j, policy->cpus) {
- if (!cpu_online(j))
- continue;
+ if (!cpu_online(j))
+ continue;
per_cpu(cpufreq_cpu_data, j) = policy;
per_cpu(policy_cpu, j) = policy->cpu;
}
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
- /* symlink affected CPUs */
- for_each_cpu(j, policy->cpus) {
- struct cpufreq_policy *managed_policy;
-
- if (j == cpu)
- continue;
- if (!cpu_online(j))
- continue;
-
- dprintk("CPU %u already managed, adding link\n", j);
- managed_policy = cpufreq_cpu_get(cpu);
- cpu_sys_dev = get_cpu_sysdev(j);
- ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj,
- "cpufreq");
- if (ret) {
- cpufreq_cpu_put(managed_policy);
- goto err_out_unregister;
- }
- }
+ ret = cpufreq_add_dev_symlink(cpu, policy);
+ if (ret)
+ goto err_out_kobj_put;
- policy->governor = NULL; /* to assure that the starting sequence is
- * run in cpufreq_set_policy */
+ memcpy(&new_policy, policy, sizeof(struct cpufreq_policy));
+ /* assure that the starting sequence is run in __cpufreq_set_policy */
+ policy->governor = NULL;
/* set default policy */
ret = __cpufreq_set_policy(policy, &new_policy);
if (ret) {
dprintk("setting policy failed\n");
- goto err_out_unregister;
+ if (cpufreq_driver->exit)
+ cpufreq_driver->exit(policy);
+ }
+ return ret;
+
+err_out_kobj_put:
+ kobject_put(&policy->kobj);
+ wait_for_completion(&policy->kobj_unregister);
+ 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 sys_device *sys_dev)
+{
+ unsigned int cpu = sys_dev->id;
+ int ret = 0;
+ struct cpufreq_policy *policy;
+ unsigned long flags;
+ unsigned int j;
+
+ if (cpu_is_offline(cpu))
+ return 0;
+
+ cpufreq_debug_disable_ratelimit();
+ dprintk("adding CPU %u\n", cpu);
+
+#ifdef CONFIG_SMP
+ /* check whether a different CPU already registered this
+ * CPU because it is in the same boat. */
+ policy = cpufreq_cpu_get(cpu);
+ if (unlikely(policy)) {
+ cpufreq_cpu_put(policy);
+ cpufreq_debug_enable_ratelimit();
+ return 0;
+ }
+#endif
+
+ if (!try_module_get(cpufreq_driver->owner)) {
+ ret = -EINVAL;
+ goto module_out;
+ }
+
+ ret = -ENOMEM;
+ policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL);
+ if (!policy)
+ goto nomem_out;
+
+ if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
+ goto err_free_policy;
+
+ if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
+ goto err_free_cpumask;
+
+ policy->cpu = cpu;
+ cpumask_copy(policy->cpus, cpumask_of(cpu));
+
+ /* Initially set CPU itself as the policy_cpu */
+ per_cpu(policy_cpu, cpu) = cpu;
+ ret = (lock_policy_rwsem_write(cpu) < 0);
+ WARN_ON(ret);
+
+ init_completion(&policy->kobj_unregister);
+ INIT_WORK(&policy->update, handle_update);
+
+ /* Set governor before ->init, so that driver could check it */
+ policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
+ /* call driver. From then on the cpufreq must be able
+ * to accept all calls to ->verify and ->setpolicy for this CPU
+ */
+ ret = cpufreq_driver->init(policy);
+ if (ret) {
+ dprintk("initialization failed\n");
+ goto err_unlock_policy;
}
+ policy->user_policy.min = policy->min;
+ policy->user_policy.max = policy->max;
+
+ blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+ CPUFREQ_START, policy);
+
+ ret = cpufreq_add_dev_policy(cpu, policy, sys_dev);
+ if (ret) {
+ if (ret > 0)
+ /* This is a managed cpu, symlink created,
+ exit with 0 */
+ ret = 0;
+ goto err_unlock_policy;
+ }
+
+ ret = cpufreq_add_dev_interface(cpu, policy, sys_dev);
+ if (ret)
+ goto err_out_unregister;
unlock_policy_rwsem_write(cpu);
per_cpu(cpufreq_cpu_data, j) = NULL;
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
-err_out_kobj_put:
kobject_put(&policy->kobj);
wait_for_completion(&policy->kobj_unregister);
-out_driver_exit:
- if (cpufreq_driver->exit)
- cpufreq_driver->exit(policy);
-
err_unlock_policy:
unlock_policy_rwsem_write(cpu);
err_free_cpumask:
dprintk("governor switch\n");
/* end old governor */
- if (data->governor)
+ if (data->governor) {
+ /*
+ * Need to release the rwsem around governor
+ * stop due to lock dependency between
+ * cancel_delayed_work_sync and the read lock
+ * taken in the delayed work handler.
+ */
+ unlock_policy_rwsem_write(data->cpu);
__cpufreq_governor(data, CPUFREQ_GOV_STOP);
+ lock_policy_rwsem_write(data->cpu);
+ }
/* start new governor */
data->governor = policy->governor;
per_cpu(policy_cpu, cpu) = -1;
init_rwsem(&per_cpu(cpu_policy_rwsem, cpu));
}
+
+ cpufreq_global_kobject = kobject_create_and_add("cpufreq",
+ &cpu_sysdev_class.kset.kobj);
+ BUG_ON(!cpufreq_global_kobject);
+
return 0;
}
-
core_initcall(cpufreq_core_init);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff