* 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)
{
struct sys_device *cpu_sys_dev;
unsigned long flags;
unsigned int j;
-#ifdef CONFIG_SMP
- struct cpufreq_policy *managed_policy;
-#endif
if (cpu_is_offline(cpu))
return 0;
goto nomem_out;
}
if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) {
- kfree(policy);
ret = -ENOMEM;
- goto nomem_out;
+ goto err_free_policy;
}
if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) {
- free_cpumask_var(policy->cpus);
- kfree(policy);
ret = -ENOMEM;
- goto nomem_out;
+ goto err_free_cpumask;
}
policy->cpu = cpu;
/* Initially set CPU itself as the policy_cpu */
per_cpu(policy_cpu, cpu) = cpu;
- lock_policy_rwsem_write(cpu);
+ ret = (lock_policy_rwsem_write(cpu) < 0);
+ WARN_ON(ret);
init_completion(&policy->kobj_unregister);
INIT_WORK(&policy->update, handle_update);
ret = cpufreq_driver->init(policy);
if (ret) {
dprintk("initialization failed\n");
- goto err_out;
+ goto err_unlock_policy;
}
policy->user_policy.min = policy->min;
policy->user_policy.max = policy->max;
#endif
for_each_cpu(j, policy->cpus) {
+ struct cpufreq_policy *managed_policy;
+
if (cpu == j)
continue;
/* Check for existing affected CPUs.
* They may not be aware of it due to CPU Hotplug.
+ * cpufreq_cpu_put is called when the device is removed
+ * in __cpufreq_remove_dev()
*/
- managed_policy = cpufreq_cpu_get(j); /* FIXME: Where is this released? What about error paths? */
+ managed_policy = cpufreq_cpu_get(j);
if (unlikely(managed_policy)) {
/* Set proper policy_cpu */
unlock_policy_rwsem_write(cpu);
per_cpu(policy_cpu, cpu) = managed_policy->cpu;
- if (lock_policy_rwsem_write(cpu) < 0)
- goto err_out_driver_exit;
+ if (lock_policy_rwsem_write(cpu) < 0) {
+ /* 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;
+ }
spin_lock_irqsave(&cpufreq_driver_lock, flags);
cpumask_copy(managed_policy->cpus, policy->cpus);
&managed_policy->kobj,
"cpufreq");
if (ret)
- goto err_out_driver_exit;
-
- cpufreq_debug_enable_ratelimit();
- ret = 0;
- goto err_out_driver_exit; /* call driver->exit() */
+ cpufreq_cpu_put(managed_policy);
+ /*
+ * Success. We only needed to be added to the mask.
+ * Call driver->exit() because only the cpu parent of
+ * the kobj needed to call init().
+ */
+ goto out_driver_exit; /* call driver->exit() */
}
}
#endif
ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, &sys_dev->kobj,
"cpufreq");
if (ret)
- goto err_out_driver_exit;
+ goto out_driver_exit;
/* set up files for this cpu device */
drv_attr = cpufreq_driver->attr;
while ((drv_attr) && (*drv_attr)) {
ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
if (ret)
- goto err_out_driver_exit;
+ goto err_out_kobj_put;
drv_attr++;
}
if (cpufreq_driver->get) {
ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
if (ret)
- goto err_out_driver_exit;
+ goto err_out_kobj_put;
}
if (cpufreq_driver->target) {
ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
if (ret)
- goto err_out_driver_exit;
+ goto err_out_kobj_put;
}
spin_lock_irqsave(&cpufreq_driver_lock, flags);
for_each_cpu(j, policy->cpus) {
+ if (!cpu_online(j))
+ continue;
per_cpu(cpufreq_cpu_data, j) = policy;
per_cpu(policy_cpu, j) = policy->cpu;
}
/* 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);
- cpufreq_cpu_get(cpu);
+ 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)
+ if (ret) {
+ cpufreq_cpu_put(managed_policy);
goto err_out_unregister;
+ }
}
policy->governor = NULL; /* to assure that the starting sequence is
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);
-err_out_driver_exit:
+out_driver_exit:
if (cpufreq_driver->exit)
cpufreq_driver->exit(policy);
-err_out:
+err_unlock_policy:
unlock_policy_rwsem_write(cpu);
+err_free_cpumask:
+ free_cpumask_var(policy->cpus);
+err_free_policy:
kfree(policy);
-
nomem_out:
module_put(cpufreq_driver->owner);
module_out:
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
#endif
- unlock_policy_rwsem_write(cpu);
-
if (cpufreq_driver->target)
__cpufreq_governor(data, CPUFREQ_GOV_STOP);
if (cpufreq_driver->exit)
cpufreq_driver->exit(data);
+ unlock_policy_rwsem_write(cpu);
+
free_cpumask_var(data->related_cpus);
free_cpumask_var(data->cpus);
kfree(data);
static int cpufreq_suspend(struct sys_device *sysdev, pm_message_t pmsg)
{
- int cpu = sysdev->id;
int ret = 0;
- unsigned int cur_freq = 0;
+
+ int cpu = sysdev->id;
struct cpufreq_policy *cpu_policy;
dprintk("suspending cpu %u\n", cpu);
if (cpufreq_driver->suspend) {
ret = cpufreq_driver->suspend(cpu_policy, pmsg);
- if (ret) {
+ if (ret)
printk(KERN_ERR "cpufreq: suspend failed in ->suspend "
"step on CPU %u\n", cpu_policy->cpu);
- goto out;
- }
- }
-
- if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)
- goto out;
-
- if (cpufreq_driver->get)
- cur_freq = cpufreq_driver->get(cpu_policy->cpu);
-
- if (!cur_freq || !cpu_policy->cur) {
- printk(KERN_ERR "cpufreq: suspend failed to assert current "
- "frequency is what timing core thinks it is.\n");
- goto out;
- }
-
- if (unlikely(cur_freq != cpu_policy->cur)) {
- struct cpufreq_freqs freqs;
-
- if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN))
- dprintk("Warning: CPU frequency is %u, "
- "cpufreq assumed %u kHz.\n",
- cur_freq, cpu_policy->cur);
-
- freqs.cpu = cpu;
- freqs.old = cpu_policy->cur;
- freqs.new = cur_freq;
-
- srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
- CPUFREQ_SUSPENDCHANGE, &freqs);
- adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs);
-
- cpu_policy->cur = cur_freq;
}
out:
* cpufreq_resume - restore proper CPU frequency handling after resume
*
* 1.) resume CPUfreq hardware support (cpufreq_driver->resume())
- * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync
- * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are
- * restored.
+ * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are
+ * restored. It will verify that the current freq is in sync with
+ * what we believe it to be. This is a bit later than when it
+ * should be, but nonethteless it's better than calling
+ * cpufreq_driver->get() here which might re-enable interrupts...
*/
static int cpufreq_resume(struct sys_device *sysdev)
{
- int cpu = sysdev->id;
int ret = 0;
+
+ int cpu = sysdev->id;
struct cpufreq_policy *cpu_policy;
dprintk("resuming cpu %u\n", cpu);
}
}
- if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
- unsigned int cur_freq = 0;
-
- if (cpufreq_driver->get)
- cur_freq = cpufreq_driver->get(cpu_policy->cpu);
-
- if (!cur_freq || !cpu_policy->cur) {
- printk(KERN_ERR "cpufreq: resume failed to assert "
- "current frequency is what timing core "
- "thinks it is.\n");
- goto out;
- }
-
- if (unlikely(cur_freq != cpu_policy->cur)) {
- struct cpufreq_freqs freqs;
-
- if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN))
- dprintk("Warning: CPU frequency "
- "is %u, cpufreq assumed %u kHz.\n",
- cur_freq, cpu_policy->cur);
-
- freqs.cpu = cpu;
- freqs.old = cpu_policy->cur;
- freqs.new = cur_freq;
-
- srcu_notifier_call_chain(
- &cpufreq_transition_notifier_list,
- CPUFREQ_RESUMECHANGE, &freqs);
- adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs);
-
- cpu_policy->cur = cur_freq;
- }
- }
-
-out:
schedule_work(&cpu_policy->update);
+
fail:
cpufreq_cpu_put(cpu_policy);
return ret;
git.openpandora.org / pandora-kernel.git / blobdiff