cpufreq.c

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									\
	ret = cpufreq_get_policy(&new_policy, policy->cpu);		\
	if (ret)							\
		return -EINVAL;						\
									\
	ret = sscanf (buf, "%u", &new_policy.object);			\
	if (ret != 1)							\
		return -EINVAL;						\
									\
	ret = __cpufreq_set_policy(policy, &new_policy);		\
	policy->user_policy.object = policy->object;			\
									\
	return ret ? ret : count;					\
}

store_one(scaling_min_freq,min);
store_one(scaling_max_freq,max);

/**
 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
 */
static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy,
							char *buf)
{
	unsigned int cur_freq = __cpufreq_get(policy->cpu);
	if (!cur_freq)
		return sprintf(buf, "<unknown>");
	return sprintf(buf, "%u\n", cur_freq);
}


/**
 * show_scaling_governor - show the current policy for the specified CPU
 */
static ssize_t show_scaling_governor (struct cpufreq_policy * policy,
							char *buf)
{
	if(policy->policy == CPUFREQ_POLICY_POWERSAVE)
		return sprintf(buf, "powersave\n");
	else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
		return sprintf(buf, "performance\n");
	else if (policy->governor)
		return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", policy->governor->name);
	return -EINVAL;
}


/**
 * store_scaling_governor - store policy for the specified CPU
 */
static ssize_t store_scaling_governor (struct cpufreq_policy * policy,
				       const char *buf, size_t count)
{
	unsigned int ret = -EINVAL;
	char	str_governor[16];
	struct cpufreq_policy new_policy;

	ret = cpufreq_get_policy(&new_policy, policy->cpu);
	if (ret)
		return ret;

	ret = sscanf (buf, "%15s", str_governor);
	if (ret != 1)
		return -EINVAL;

	if (cpufreq_parse_governor(str_governor, &new_policy.policy,
						&new_policy.governor))
		return -EINVAL;

	/* Do not use cpufreq_set_policy here or the user_policy.max
	   will be wrongly overridden */
	ret = __cpufreq_set_policy(policy, &new_policy);

	policy->user_policy.policy = policy->policy;
	policy->user_policy.governor = policy->governor;

	if (ret)
		return ret;
	else
		return count;
}

/**
 * show_scaling_driver - show the cpufreq driver currently loaded
 */
static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf)
{
	return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name);
}

/**
 * show_scaling_available_governors - show the available CPUfreq governors
 */
static ssize_t show_scaling_available_governors (struct cpufreq_policy *policy,
				char *buf)
{
	ssize_t i = 0;
	struct cpufreq_governor *t;

	if (!cpufreq_driver->target) {
		i += sprintf(buf, "performance powersave");
		goto out;
	}

	list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
		if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) - (CPUFREQ_NAME_LEN + 2)))
			goto out;
		i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name);
	}
out:
	i += sprintf(&buf[i], "\n");
	return i;
}
/**
 * show_affected_cpus - show the CPUs affected by each transition
 */
static ssize_t show_affected_cpus (struct cpufreq_policy * policy, char *buf)
{
	ssize_t i = 0;
	unsigned int cpu;

	for_each_cpu_mask(cpu, policy->cpus) {
		if (i)
			i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
		i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
		if (i >= (PAGE_SIZE - 5))
		    break;
	}
	i += sprintf(&buf[i], "\n");
	return i;
}


#define define_one_ro(_name) \
static struct freq_attr _name = \
__ATTR(_name, 0444, show_##_name, NULL)

#define define_one_ro0400(_name) \
static struct freq_attr _name = \
__ATTR(_name, 0400, show_##_name, NULL)

#define define_one_rw(_name) \
static struct freq_attr _name = \
__ATTR(_name, 0644, show_##_name, store_##_name)

define_one_ro0400(cpuinfo_cur_freq);
define_one_ro(cpuinfo_min_freq);
define_one_ro(cpuinfo_max_freq);
define_one_ro(scaling_available_governors);
define_one_ro(scaling_driver);
define_one_ro(scaling_cur_freq);
define_one_ro(affected_cpus);
define_one_rw(scaling_min_freq);
define_one_rw(scaling_max_freq);
define_one_rw(scaling_governor);

static struct attribute * default_attrs[] = {
	&cpuinfo_min_freq.attr,
	&cpuinfo_max_freq.attr,
	&scaling_min_freq.attr,
	&scaling_max_freq.attr,
	&affected_cpus.attr,
	&scaling_governor.attr,
	&scaling_driver.attr,
	&scaling_available_governors.attr,
	NULL
};

#define to_policy(k) container_of(k,struct cpufreq_policy,kobj)
#define to_attr(a) container_of(a,struct freq_attr,attr)

static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf)
{
	struct cpufreq_policy * policy = to_policy(kobj);
	struct freq_attr * fattr = to_attr(attr);
	ssize_t ret;
	policy = cpufreq_cpu_get(policy->cpu);
	if (!policy)
		return -EINVAL;

	if (lock_policy_rwsem_read(policy->cpu) < 0)
		return -EINVAL;

	if (fattr->show)
		ret = fattr->show(policy, buf);
	else
		ret = -EIO;

	unlock_policy_rwsem_read(policy->cpu);

	cpufreq_cpu_put(policy);
	return ret;
}

static ssize_t store(struct kobject * kobj, struct attribute * attr,
		     const char * buf, size_t count)
{
	struct cpufreq_policy * policy = to_policy(kobj);
	struct freq_attr * fattr = to_attr(attr);
	ssize_t ret;
	policy = cpufreq_cpu_get(policy->cpu);
	if (!policy)
		return -EINVAL;

	if (lock_policy_rwsem_write(policy->cpu) < 0)
		return -EINVAL;

	if (fattr->store)
		ret = fattr->store(policy, buf, count);
	else
		ret = -EIO;

	unlock_policy_rwsem_write(policy->cpu);

	cpufreq_cpu_put(policy);
	return ret;
}

static void cpufreq_sysfs_release(struct kobject * kobj)
{
	struct cpufreq_policy * policy = to_policy(kobj);
	dprintk("last reference is dropped\n");
	complete(&policy->kobj_unregister);
}

static struct sysfs_ops sysfs_ops = {
	.show	= show,
	.store	= store,
};

static struct kobj_type ktype_cpufreq = {
	.sysfs_ops	= &sysfs_ops,
	.default_attrs	= default_attrs,
	.release	= cpufreq_sysfs_release,
};


/**
 * cpufreq_add_dev - add a CPU device
 *
 * Adds the cpufreq interface for a CPU device.
 */
static int cpufreq_add_dev (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;
	unsigned long flags;
	unsigned int j;
#ifdef CONFIG_SMP
	struct cpufreq_policy *managed_policy;
#endif

	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;
	}

	policy->cpu = cpu;
	policy->cpus = cpumask_of_cpu(cpu);

	/* Initially set CPU itself as the policy_cpu */
	per_cpu(policy_cpu, cpu) = cpu;
	lock_policy_rwsem_write(cpu);

	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");
		unlock_policy_rwsem_write(cpu);
		goto err_out;
	}
	policy->user_policy.min = policy->cpuinfo.min_freq;
	policy->user_policy.max = policy->cpuinfo.max_freq;

#ifdef CONFIG_SMP

#ifdef CONFIG_HOTPLUG_CPU
	if (cpufreq_cpu_governor[cpu]){
		policy->governor = cpufreq_cpu_governor[cpu];
		dprintk("Restoring governor %s for cpu %d\n",
		       policy->governor->name, cpu);
	}
#endif

	for_each_cpu_mask(j, policy->cpus) {
		if (cpu == j)
			continue;

		/* check for existing affected CPUs.  They may not be aware
		 * of it due to CPU Hotplug.
		 */
		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;

			spin_lock_irqsave(&cpufreq_driver_lock, flags);
			managed_policy->cpus = policy->cpus;
			cpufreq_cpu_data[cpu] = managed_policy;
			spin_unlock_irqrestore(&cpufreq_driver_lock, flags);

			dprintk("CPU already managed, adding link\n");
			ret = sysfs_create_link(&sys_dev->kobj,
						&managed_policy->kobj,
						"cpufreq");
			if (ret) {
				unlock_policy_rwsem_write(cpu);
				goto err_out_driver_exit;
			}

			cpufreq_debug_enable_ratelimit();
			ret = 0;
			unlock_policy_rwsem_write(cpu);
			goto err_out_driver_exit; /* call driver->exit() */
		}
	}
#endif
	memcpy(&new_policy, policy, sizeof(struct cpufreq_policy));

	/* prepare interface data */
	policy->kobj.parent = &sys_dev->kobj;
	policy->kobj.ktype = &ktype_cpufreq;
	kobject_set_name(&policy->kobj, "cpufreq");

	ret = kobject_register(&policy->kobj);
	if (ret) {
		unlock_policy_rwsem_write(cpu);
		goto err_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) {
			unlock_policy_rwsem_write(cpu);
			goto err_out_driver_exit;
		}
		drv_attr++;
	}
	if (cpufreq_driver->get){
		ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
		if (ret) {
			unlock_policy_rwsem_write(cpu);
			goto err_out_driver_exit;
		}
	}
	if (cpufreq_driver->target){
		ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
		if (ret) {
			unlock_policy_rwsem_write(cpu);
			goto err_out_driver_exit;
		}
	}

	spin_lock_irqsave(&cpufreq_driver_lock, flags);
	for_each_cpu_mask(j, policy->cpus) {
		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_mask(j, policy->cpus) {
		if (j == cpu)
			continue;
		if (!cpu_online(j))
			continue;

		dprintk("CPU %u already managed, adding link\n", j);
		cpufreq_cpu_get(cpu);
		cpu_sys_dev = get_cpu_sysdev(j);
		ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj,
					"cpufreq");
		if (ret) {
			unlock_policy_rwsem_write(cpu);
			goto err_out_unregister;
		}
	}

	policy->governor = NULL; /* to assure that the starting sequence is
				  * run in cpufreq_set_policy */

	/* set default policy */
	ret = __cpufreq_set_policy(policy, &new_policy);
	policy->user_policy.policy = policy->policy;
	policy->user_policy.governor = policy->governor;

	unlock_policy_rwsem_write(cpu);

	if (ret) {
		dprintk("setting policy failed\n");
		goto err_out_unregister;
	}

	module_put(cpufreq_driver->owner);
	dprintk("initialization complete\n");
	cpufreq_debug_enable_ratelimit();

	return 0;


err_out_unregister:
	spin_lock_irqsave(&cpufreq_driver_lock, flags);
	for_each_cpu_mask(j, policy->cpus)
		cpufreq_cpu_data[j] = NULL;
	spin_unlock_irqrestore(&cpufreq_driver_lock, flags);

	kobject_unregister(&policy->kobj);
	wait_for_completion(&policy->kobj_unregister);

err_out_driver_exit:
	if (cpufreq_driver->exit)
		cpufreq_driver->exit(policy);

err_out:
	kfree(policy);

nomem_out:
	module_put(cpufreq_driver->owner);
module_out:
	cpufreq_debug_enable_ratelimit();
	return ret;
}


/**
 * __cpufreq_remove_dev - remove a CPU device
 *
 * Removes the cpufreq interface for a CPU device.
 * Caller should already have policy_rwsem in write mode for this CPU.
 * This routine frees the rwsem before returning.
 */