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32 results

sysfs.c

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  • sysfs.c 15.23 KiB
    /*
     * sysfs.c - sysfs support
     *
     * (C) 2006-2007 Shaohua Li <shaohua.li@intel.com>
     *
     * This code is licenced under the GPL.
     */
    
    #include <linux/kernel.h>
    #include <linux/cpuidle.h>
    #include <linux/sysfs.h>
    #include <linux/slab.h>
    #include <linux/cpu.h>
    #include <linux/capability.h>
    #include <linux/device.h>
    
    #include "cpuidle.h"
    
    static unsigned int sysfs_switch;
    static int __init cpuidle_sysfs_setup(char *unused)
    {
    	sysfs_switch = 1;
    	return 1;
    }
    __setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);
    
    static ssize_t show_available_governors(struct device *dev,
    					struct device_attribute *attr,
    					char *buf)
    {
    	ssize_t i = 0;
    	struct cpuidle_governor *tmp;
    
    	mutex_lock(&cpuidle_lock);
    	list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
    		if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) - CPUIDLE_NAME_LEN - 2))
    			goto out;
    		i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
    	}
    
    out:
    	i+= sprintf(&buf[i], "\n");
    	mutex_unlock(&cpuidle_lock);
    	return i;
    }
    
    static ssize_t show_current_driver(struct device *dev,
    				   struct device_attribute *attr,
    				   char *buf)
    {
    	ssize_t ret;
    	struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
    
    	spin_lock(&cpuidle_driver_lock);
    	if (cpuidle_driver)
    		ret = sprintf(buf, "%s\n", cpuidle_driver->name);
    	else
    		ret = sprintf(buf, "none\n");
    	spin_unlock(&cpuidle_driver_lock);
    
    	return ret;
    }
    
    static ssize_t show_current_governor(struct device *dev,
    				     struct device_attribute *attr,
    				     char *buf)
    {
    	ssize_t ret;
    
    	mutex_lock(&cpuidle_lock);
    	if (cpuidle_curr_governor)
    		ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
    	else
    		ret = sprintf(buf, "none\n");
    	mutex_unlock(&cpuidle_lock);
    
    	return ret;
    }
    
    static ssize_t store_current_governor(struct device *dev,
    				      struct device_attribute *attr,
    				      const char *buf, size_t count)
    {
    	char gov_name[CPUIDLE_NAME_LEN];
    	int ret = -EINVAL;
    	size_t len = count;
    	struct cpuidle_governor *gov;
    
    	if (!len || len >= sizeof(gov_name))
    		return -EINVAL;
    
    	memcpy(gov_name, buf, len);
    	gov_name[len] = '\0';
    	if (gov_name[len - 1] == '\n')
    		gov_name[--len] = '\0';
    
    	mutex_lock(&cpuidle_lock);
    
    	list_for_each_entry(gov, &cpuidle_governors, governor_list) {
    		if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
    			ret = cpuidle_switch_governor(gov);
    			break;
    		}
    	}
    
    	mutex_unlock(&cpuidle_lock);
    
    	if (ret)
    		return ret;
    	else
    		return count;
    }
    
    static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
    static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
    
    static struct attribute *cpuidle_default_attrs[] = {
    	&dev_attr_current_driver.attr,
    	&dev_attr_current_governor_ro.attr,
    	NULL
    };
    
    static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
    static DEVICE_ATTR(current_governor, 0644, show_current_governor,
    		   store_current_governor);
    
    static struct attribute *cpuidle_switch_attrs[] = {
    	&dev_attr_available_governors.attr,
    	&dev_attr_current_driver.attr,
    	&dev_attr_current_governor.attr,
    	NULL
    };
    
    static struct attribute_group cpuidle_attr_group = {
    	.attrs = cpuidle_default_attrs,
    	.name = "cpuidle",
    };
    
    /**
     * cpuidle_add_interface - add CPU global sysfs attributes
     */
    int cpuidle_add_interface(struct device *dev)
    {
    	if (sysfs_switch)
    		cpuidle_attr_group.attrs = cpuidle_switch_attrs;
    
    	return sysfs_create_group(&dev->kobj, &cpuidle_attr_group);
    }
    
    /**
     * cpuidle_remove_interface - remove CPU global sysfs attributes
     */
    void cpuidle_remove_interface(struct device *dev)
    {
    	sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
    }
    
    struct cpuidle_attr {
    	struct attribute attr;
    	ssize_t (*show)(struct cpuidle_device *, char *);
    	ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
    };
    
    #define define_one_ro(_name, show) \
    	static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
    #define define_one_rw(_name, show, store) \
    	static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
    
    #define kobj_to_cpuidledev(k) container_of(k, struct cpuidle_device, kobj)
    #define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
    static ssize_t cpuidle_show(struct kobject * kobj, struct attribute * attr ,char * buf)
    {
    	int ret = -EIO;
    	struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
    	struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
    
    	if (cattr->show) {
    		mutex_lock(&cpuidle_lock);
    		ret = cattr->show(dev, buf);
    		mutex_unlock(&cpuidle_lock);
    	}
    	return ret;
    }
    
    static ssize_t cpuidle_store(struct kobject * kobj, struct attribute * attr,
    		     const char * buf, size_t count)
    {
    	int ret = -EIO;
    	struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
    	struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
    
    	if (cattr->store) {
    		mutex_lock(&cpuidle_lock);
    		ret = cattr->store(dev, buf, count);
    		mutex_unlock(&cpuidle_lock);
    	}
    	return ret;
    }
    
    static const struct sysfs_ops cpuidle_sysfs_ops = {
    	.show = cpuidle_show,
    	.store = cpuidle_store,
    };
    
    static void cpuidle_sysfs_release(struct kobject *kobj)
    {
    	struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
    
    	complete(&dev->kobj_unregister);
    }
    
    static struct kobj_type ktype_cpuidle = {
    	.sysfs_ops = &cpuidle_sysfs_ops,
    	.release = cpuidle_sysfs_release,
    };
    
    struct cpuidle_state_attr {
    	struct attribute attr;
    	ssize_t (*show)(struct cpuidle_state *, \
    					struct cpuidle_state_usage *, char *);
    	ssize_t (*store)(struct cpuidle_state *, \
    			struct cpuidle_state_usage *, const char *, size_t);
    };
    
    #define define_one_state_ro(_name, show) \
    static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
    
    #define define_one_state_rw(_name, show, store) \
    static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
    
    #define define_show_state_function(_name) \
    static ssize_t show_state_##_name(struct cpuidle_state *state, \
    			 struct cpuidle_state_usage *state_usage, char *buf) \
    { \
    	return sprintf(buf, "%u\n", state->_name);\
    }
    
    #define define_store_state_ull_function(_name) \
    static ssize_t store_state_##_name(struct cpuidle_state *state, \
    		struct cpuidle_state_usage *state_usage, \
    		const char *buf, size_t size) \
    { \
    	unsigned long long value; \
    	int err; \
    	if (!capable(CAP_SYS_ADMIN)) \
    		return -EPERM; \
    	err = kstrtoull(buf, 0, &value); \
    	if (err) \
    		return err; \
    	if (value) \
    		state_usage->_name = 1; \
    	else \
    		state_usage->_name = 0; \
    	return size; \
    }
    
    #define define_show_state_ull_function(_name) \
    static ssize_t show_state_##_name(struct cpuidle_state *state, \
    			struct cpuidle_state_usage *state_usage, char *buf) \
    { \
    	return sprintf(buf, "%llu\n", state_usage->_name);\
    }
    
    #define define_show_state_str_function(_name) \
    static ssize_t show_state_##_name(struct cpuidle_state *state, \
    			struct cpuidle_state_usage *state_usage, char *buf) \
    { \
    	if (state->_name[0] == '\0')\
    		return sprintf(buf, "<null>\n");\
    	return sprintf(buf, "%s\n", state->_name);\
    }
    
    define_show_state_function(exit_latency)
    define_show_state_function(power_usage)
    define_show_state_ull_function(usage)
    define_show_state_ull_function(time)
    define_show_state_str_function(name)
    define_show_state_str_function(desc)
    define_show_state_ull_function(disable)
    define_store_state_ull_function(disable)
    
    define_one_state_ro(name, show_state_name);
    define_one_state_ro(desc, show_state_desc);
    define_one_state_ro(latency, show_state_exit_latency);
    define_one_state_ro(power, show_state_power_usage);
    define_one_state_ro(usage, show_state_usage);
    define_one_state_ro(time, show_state_time);
    define_one_state_rw(disable, show_state_disable, store_state_disable);
    
    static struct attribute *cpuidle_state_default_attrs[] = {
    	&attr_name.attr,
    	&attr_desc.attr,
    	&attr_latency.attr,
    	&attr_power.attr,
    	&attr_usage.attr,
    	&attr_time.attr,
    	&attr_disable.attr,
    	NULL
    };
    
    struct cpuidle_state_kobj {
    	struct cpuidle_state *state;
    	struct cpuidle_state_usage *state_usage;
    	struct completion kobj_unregister;
    	struct kobject kobj;
    };
    
    #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
    #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
    #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
    #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
    static ssize_t cpuidle_state_show(struct kobject * kobj,
    	struct attribute * attr ,char * buf)
    {
    	int ret = -EIO;
    	struct cpuidle_state *state = kobj_to_state(kobj);
    	struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
    	struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
    
    	if (cattr->show)
    		ret = cattr->show(state, state_usage, buf);
    
    	return ret;
    }
    
    static ssize_t cpuidle_state_store(struct kobject *kobj,
    	struct attribute *attr, const char *buf, size_t size)
    {
    	int ret = -EIO;
    	struct cpuidle_state *state = kobj_to_state(kobj);
    	struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
    	struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
    
    	if (cattr->store)
    		ret = cattr->store(state, state_usage, buf, size);
    
    	return ret;
    }
    
    static const struct sysfs_ops cpuidle_state_sysfs_ops = {
    	.show = cpuidle_state_show,
    	.store = cpuidle_state_store,
    };
    
    static void cpuidle_state_sysfs_release(struct kobject *kobj)
    {
    	struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
    
    	complete(&state_obj->kobj_unregister);
    }
    
    static struct kobj_type ktype_state_cpuidle = {
    	.sysfs_ops = &cpuidle_state_sysfs_ops,
    	.default_attrs = cpuidle_state_default_attrs,
    	.release = cpuidle_state_sysfs_release,
    };
    
    static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
    {
    	kobject_put(&device->kobjs[i]->kobj);
    	wait_for_completion(&device->kobjs[i]->kobj_unregister);
    	kfree(device->kobjs[i]);
    	device->kobjs[i] = NULL;
    }
    
    /**
     * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes
     * @device: the target device
     */
    static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
    {
    	int i, ret = -ENOMEM;
    	struct cpuidle_state_kobj *kobj;
    	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
    
    	/* state statistics */
    	for (i = 0; i < device->state_count; i++) {
    		kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
    		if (!kobj)
    			goto error_state;
    		kobj->state = &drv->states[i];
    		kobj->state_usage = &device->states_usage[i];
    		init_completion(&kobj->kobj_unregister);
    
    		ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
    					   &device->kobj, "state%d", i);
    		if (ret) {
    			kfree(kobj);
    			goto error_state;
    		}
    		kobject_uevent(&kobj->kobj, KOBJ_ADD);
    		device->kobjs[i] = kobj;
    	}
    
    	return 0;
    
    error_state:
    	for (i = i - 1; i >= 0; i--)
    		cpuidle_free_state_kobj(device, i);
    	return ret;
    }
    
    /**
     * cpuidle_remove_driver_sysfs - removes the cpuidle states sysfs attributes
     * @device: the target device
     */
    static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
    {
    	int i;
    
    	for (i = 0; i < device->state_count; i++)
    		cpuidle_free_state_kobj(device, i);
    }
    
    #ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
    #define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
    #define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
    
    #define define_one_driver_ro(_name, show)                       \
    	static struct cpuidle_driver_attr attr_driver_##_name = \
    		__ATTR(_name, 0644, show, NULL)
    
    struct cpuidle_driver_kobj {
    	struct cpuidle_driver *drv;
    	struct completion kobj_unregister;
    	struct kobject kobj;
    };
    
    struct cpuidle_driver_attr {
    	struct attribute attr;
    	ssize_t (*show)(struct cpuidle_driver *, char *);
    	ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
    };
    
    static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
    {
    	ssize_t ret;
    
    	spin_lock(&cpuidle_driver_lock);
    	ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
    	spin_unlock(&cpuidle_driver_lock);
    
    	return ret;
    }
    
    static void cpuidle_driver_sysfs_release(struct kobject *kobj)
    {
    	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
    	complete(&driver_kobj->kobj_unregister);
    }
    
    static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute * attr,
    				   char * buf)
    {
    	int ret = -EIO;
    	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
    	struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
    
    	if (dattr->show)
    		ret = dattr->show(driver_kobj->drv, buf);
    
    	return ret;
    }
    
    static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
    				    const char *buf, size_t size)
    {
    	int ret = -EIO;
    	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
    	struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
    
    	if (dattr->store)
    		ret = dattr->store(driver_kobj->drv, buf, size);
    
    	return ret;
    }
    
    define_one_driver_ro(name, show_driver_name);
    
    static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
    	.show = cpuidle_driver_show,
    	.store = cpuidle_driver_store,
    };
    
    static struct attribute *cpuidle_driver_default_attrs[] = {
    	&attr_driver_name.attr,
    	NULL
    };
    
    static struct kobj_type ktype_driver_cpuidle = {
    	.sysfs_ops = &cpuidle_driver_sysfs_ops,
    	.default_attrs = cpuidle_driver_default_attrs,
    	.release = cpuidle_driver_sysfs_release,
    };
    
    /**
     * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
     * @device: the target device
     */
    static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
    {
    	struct cpuidle_driver_kobj *kdrv;
    	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
    	int ret;
    
    	kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
    	if (!kdrv)
    		return -ENOMEM;
    
    	kdrv->drv = drv;
    	init_completion(&kdrv->kobj_unregister);
    
    	ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
    				   &dev->kobj, "driver");
    	if (ret) {
    		kfree(kdrv);
    		return ret;
    	}
    
    	kobject_uevent(&kdrv->kobj, KOBJ_ADD);
    	dev->kobj_driver = kdrv;
    
    	return ret;
    }
    
    /**
     * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
     * @device: the target device
     */
    static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
    {
    	struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
    	kobject_put(&kdrv->kobj);
    	wait_for_completion(&kdrv->kobj_unregister);
    	kfree(kdrv);
    }
    #else
    static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
    {
    	return 0;
    }
    
    static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
    {
    	;
    }
    #endif
    
    /**
     * cpuidle_add_device_sysfs - adds device specific sysfs attributes
     * @device: the target device
     */
    int cpuidle_add_device_sysfs(struct cpuidle_device *device)
    {
    	int ret;
    
    	ret = cpuidle_add_state_sysfs(device);
    	if (ret)
    		return ret;
    
    	ret = cpuidle_add_driver_sysfs(device);
    	if (ret)
    		cpuidle_remove_state_sysfs(device);
    	return ret;
    }
    
    /**
     * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
     * @device : the target device
     */
    void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
    {
    	cpuidle_remove_driver_sysfs(device);
    	cpuidle_remove_state_sysfs(device);
    }
    
    /**
     * cpuidle_add_sysfs - creates a sysfs instance for the target device
     * @dev: the target device
     */
    int cpuidle_add_sysfs(struct cpuidle_device *dev)
    {
    	struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
    	int error;
    
    	init_completion(&dev->kobj_unregister);
    
    	error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
    				     "cpuidle");
    	if (!error)
    		kobject_uevent(&dev->kobj, KOBJ_ADD);
    	return error;
    }
    
    /**
     * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
     * @dev: the target device
     */
    void cpuidle_remove_sysfs(struct cpuidle_device *dev)
    {
    	kobject_put(&dev->kobj);
    	wait_for_completion(&dev->kobj_unregister);
    }