IBMASM: dont use extern in function declarations
[safe/jmp/linux-2.6] / drivers / base / class.c
index c3e5697..4d22226 100644 (file)
  *
  */
 
-#include <linux/config.h>
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/string.h>
 #include <linux/kdev_t.h>
 #include <linux/err.h>
+#include <linux/slab.h>
 #include "base.h"
 
 #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
-#define to_class(obj) container_of(obj, struct class, subsys.kset.kobj)
+#define to_class(obj) container_of(obj, struct class, subsys.kobj)
 
 static ssize_t
 class_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
@@ -78,7 +78,7 @@ int class_create_file(struct class * cls, const struct class_attribute * attr)
 {
        int error;
        if (cls) {
-               error = sysfs_create_file(&cls->subsys.kset.kobj, &attr->attr);
+               error = sysfs_create_file(&cls->subsys.kobj, &attr->attr);
        } else
                error = -EINVAL;
        return error;
@@ -87,17 +87,17 @@ int class_create_file(struct class * cls, const struct class_attribute * attr)
 void class_remove_file(struct class * cls, const struct class_attribute * attr)
 {
        if (cls)
-               sysfs_remove_file(&cls->subsys.kset.kobj, &attr->attr);
+               sysfs_remove_file(&cls->subsys.kobj, &attr->attr);
 }
 
-struct class * class_get(struct class * cls)
+static struct class *class_get(struct class *cls)
 {
        if (cls)
                return container_of(subsys_get(&cls->subsys), struct class, subsys);
        return NULL;
 }
 
-void class_put(struct class * cls)
+static void class_put(struct class * cls)
 {
        if (cls)
                subsys_put(&cls->subsys);
@@ -141,9 +141,11 @@ int class_register(struct class * cls)
        pr_debug("device class '%s': registering\n", cls->name);
 
        INIT_LIST_HEAD(&cls->children);
+       INIT_LIST_HEAD(&cls->devices);
        INIT_LIST_HEAD(&cls->interfaces);
+       kset_init(&cls->class_dirs);
        init_MUTEX(&cls->sem);
-       error = kobject_set_name(&cls->subsys.kset.kobj, "%s", cls->name);
+       error = kobject_set_name(&cls->subsys.kobj, "%s", cls->name);
        if (error)
                return error;
 
@@ -177,7 +179,7 @@ static void class_device_create_release(struct class_device *class_dev)
 }
 
 /* needed to allow these devices to have parent class devices */
-static int class_device_create_hotplug(struct class_device *class_dev,
+static int class_device_create_uevent(struct class_device *class_dev,
                                       char **envp, int num_envp,
                                       char *buffer, int buffer_size)
 {
@@ -196,7 +198,7 @@ static int class_device_create_hotplug(struct class_device *class_dev,
  * Note, the pointer created here is to be destroyed when finished by
  * making a call to class_destroy().
  */
-struct class *class_create(struct module *owner, char *name)
+struct class *class_create(struct module *owner, const char *name)
 {
        struct class *cls;
        int retval;
@@ -225,7 +227,7 @@ error:
 
 /**
  * class_destroy - destroys a struct class structure
- * @cs: pointer to the struct class that is to be destroyed
+ * @cls: pointer to the struct class that is to be destroyed
  *
  * Note, the pointer to be destroyed must have been created with a call
  * to class_create().
@@ -310,9 +312,6 @@ static void class_dev_release(struct kobject * kobj)
 
        pr_debug("device class '%s': release.\n", cd->class_id);
 
-       kfree(cd->devt_attr);
-       cd->devt_attr = NULL;
-
        if (cd->release)
                cd->release(cd);
        else if (cls->release)
@@ -330,7 +329,7 @@ static struct kobj_type ktype_class_device = {
        .release        = class_dev_release,
 };
 
-static int class_hotplug_filter(struct kset *kset, struct kobject *kobj)
+static int class_uevent_filter(struct kset *kset, struct kobject *kobj)
 {
        struct kobj_type *ktype = get_ktype(kobj);
 
@@ -342,51 +341,107 @@ static int class_hotplug_filter(struct kset *kset, struct kobject *kobj)
        return 0;
 }
 
-static const char *class_hotplug_name(struct kset *kset, struct kobject *kobj)
+static const char *class_uevent_name(struct kset *kset, struct kobject *kobj)
 {
        struct class_device *class_dev = to_class_dev(kobj);
 
        return class_dev->class->name;
 }
 
-static int class_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
+#ifdef CONFIG_SYSFS_DEPRECATED
+char *make_class_name(const char *name, struct kobject *kobj)
+{
+       char *class_name;
+       int size;
+
+       size = strlen(name) + strlen(kobject_name(kobj)) + 2;
+
+       class_name = kmalloc(size, GFP_KERNEL);
+       if (!class_name)
+               return NULL;
+
+       strcpy(class_name, name);
+       strcat(class_name, ":");
+       strcat(class_name, kobject_name(kobj));
+       return class_name;
+}
+
+static int make_deprecated_class_device_links(struct class_device *class_dev)
+{
+       char *class_name;
+       int error;
+
+       if (!class_dev->dev)
+               return 0;
+
+       class_name = make_class_name(class_dev->class->name, &class_dev->kobj);
+       if (class_name)
+               error = sysfs_create_link(&class_dev->dev->kobj,
+                                         &class_dev->kobj, class_name);
+       else
+               error = -ENOMEM;
+       kfree(class_name);
+       return error;
+}
+
+static void remove_deprecated_class_device_links(struct class_device *class_dev)
+{
+       char *class_name;
+
+       if (!class_dev->dev)
+               return;
+
+       class_name = make_class_name(class_dev->class->name, &class_dev->kobj);
+       if (class_name)
+               sysfs_remove_link(&class_dev->dev->kobj, class_name);
+       kfree(class_name);
+}
+#else
+static inline int make_deprecated_class_device_links(struct class_device *cd)
+{ return 0; }
+static void remove_deprecated_class_device_links(struct class_device *cd)
+{ }
+#endif
+
+static int class_uevent(struct kset *kset, struct kobject *kobj, char **envp,
                         int num_envp, char *buffer, int buffer_size)
 {
        struct class_device *class_dev = to_class_dev(kobj);
+       struct device *dev = class_dev->dev;
        int i = 0;
        int length = 0;
        int retval = 0;
 
        pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
 
-       if (class_dev->dev) {
-               /* add physical device, backing this device  */
-               struct device *dev = class_dev->dev;
-               char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
+       if (MAJOR(class_dev->devt)) {
+               add_uevent_var(envp, num_envp, &i,
+                              buffer, buffer_size, &length,
+                              "MAJOR=%u", MAJOR(class_dev->devt));
 
-               add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,
-                                   &length, "PHYSDEVPATH=%s", path);
-               kfree(path);
+               add_uevent_var(envp, num_envp, &i,
+                              buffer, buffer_size, &length,
+                              "MINOR=%u", MINOR(class_dev->devt));
+       }
+
+       if (dev) {
+               const char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
+               if (path) {
+                       add_uevent_var(envp, num_envp, &i,
+                                      buffer, buffer_size, &length,
+                                      "PHYSDEVPATH=%s", path);
+                       kfree(path);
+               }
 
                if (dev->bus)
-                       add_hotplug_env_var(envp, num_envp, &i,
-                                           buffer, buffer_size, &length,
-                                           "PHYSDEVBUS=%s", dev->bus->name);
+                       add_uevent_var(envp, num_envp, &i,
+                                      buffer, buffer_size, &length,
+                                      "PHYSDEVBUS=%s", dev->bus->name);
 
                if (dev->driver)
-                       add_hotplug_env_var(envp, num_envp, &i,
-                                           buffer, buffer_size, &length,
-                                           "PHYSDEVDRIVER=%s", dev->driver->name);
-       }
-
-       if (MAJOR(class_dev->devt)) {
-               add_hotplug_env_var(envp, num_envp, &i,
-                                   buffer, buffer_size, &length,
-                                   "MAJOR=%u", MAJOR(class_dev->devt));
-
-               add_hotplug_env_var(envp, num_envp, &i,
-                                   buffer, buffer_size, &length,
-                                   "MINOR=%u", MINOR(class_dev->devt));
+                       add_uevent_var(envp, num_envp, &i,
+                                      buffer, buffer_size, &length,
+                                      "PHYSDEVDRIVER=%s", dev->driver->name);
        }
 
        /* terminate, set to next free slot, shrink available space */
@@ -396,30 +451,30 @@ static int class_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
        buffer = &buffer[length];
        buffer_size -= length;
 
-       if (class_dev->hotplug) {
+       if (class_dev->uevent) {
                /* have the class device specific function add its stuff */
-               retval = class_dev->hotplug(class_dev, envp, num_envp,
+               retval = class_dev->uevent(class_dev, envp, num_envp,
                                            buffer, buffer_size);
                if (retval)
-                       pr_debug("class_dev->hotplug() returned %d\n", retval);
-       } else if (class_dev->class->hotplug) {
+                       pr_debug("class_dev->uevent() returned %d\n", retval);
+       } else if (class_dev->class->uevent) {
                /* have the class specific function add its stuff */
-               retval = class_dev->class->hotplug(class_dev, envp, num_envp,
+               retval = class_dev->class->uevent(class_dev, envp, num_envp,
                                                   buffer, buffer_size);
                if (retval)
-                       pr_debug("class->hotplug() returned %d\n", retval);
+                       pr_debug("class->uevent() returned %d\n", retval);
        }
 
        return retval;
 }
 
-static struct kset_hotplug_ops class_hotplug_ops = {
-       .filter =       class_hotplug_filter,
-       .name =         class_hotplug_name,
-       .hotplug =      class_hotplug,
+static struct kset_uevent_ops class_uevent_ops = {
+       .filter =       class_uevent_filter,
+       .name =         class_uevent_name,
+       .uevent =       class_uevent,
 };
 
-static decl_subsys(class_obj, &ktype_class_device, &class_hotplug_ops);
+static decl_subsys(class_obj, &ktype_class_device, &class_uevent_ops);
 
 
 static int class_device_add_attrs(struct class_device * cd)
@@ -455,18 +510,53 @@ static void class_device_remove_attrs(struct class_device * cd)
        }
 }
 
+static int class_device_add_groups(struct class_device * cd)
+{
+       int i;
+       int error = 0;
+
+       if (cd->groups) {
+               for (i = 0; cd->groups[i]; i++) {
+                       error = sysfs_create_group(&cd->kobj, cd->groups[i]);
+                       if (error) {
+                               while (--i >= 0)
+                                       sysfs_remove_group(&cd->kobj, cd->groups[i]);
+                               goto out;
+                       }
+               }
+       }
+out:
+       return error;
+}
+
+static void class_device_remove_groups(struct class_device * cd)
+{
+       int i;
+       if (cd->groups) {
+               for (i = 0; cd->groups[i]; i++) {
+                       sysfs_remove_group(&cd->kobj, cd->groups[i]);
+               }
+       }
+}
+
 static ssize_t show_dev(struct class_device *class_dev, char *buf)
 {
        return print_dev_t(buf, class_dev->devt);
 }
 
+static struct class_device_attribute class_devt_attr =
+       __ATTR(dev, S_IRUGO, show_dev, NULL);
+
 static ssize_t store_uevent(struct class_device *class_dev,
                            const char *buf, size_t count)
 {
-       kobject_hotplug(&class_dev->kobj, KOBJ_ADD);
+       kobject_uevent(&class_dev->kobj, KOBJ_ADD);
        return count;
 }
 
+static struct class_device_attribute class_uevent_attr =
+       __ATTR(uevent, S_IWUSR, NULL, store_uevent);
+
 void class_device_initialize(struct class_device *class_dev)
 {
        kobj_set_kset_s(class_dev, class_obj_subsys);
@@ -474,30 +564,11 @@ void class_device_initialize(struct class_device *class_dev)
        INIT_LIST_HEAD(&class_dev->node);
 }
 
-static char *make_class_name(struct class_device *class_dev)
-{
-       char *name;
-       int size;
-
-       size = strlen(class_dev->class->name) +
-               strlen(kobject_name(&class_dev->kobj)) + 2;
-
-       name = kmalloc(size, GFP_KERNEL);
-       if (!name)
-               return ERR_PTR(-ENOMEM);
-
-       strcpy(name, class_dev->class->name);
-       strcat(name, ":");
-       strcat(name, kobject_name(&class_dev->kobj));
-       return name;
-}
-
 int class_device_add(struct class_device *class_dev)
 {
        struct class *parent_class = NULL;
        struct class_device *parent_class_dev = NULL;
        struct class_interface *class_intf;
-       char *class_name = NULL;
        int error = -EINVAL;
 
        class_dev = class_device_get(class_dev);
@@ -505,78 +576,99 @@ int class_device_add(struct class_device *class_dev)
                return -EINVAL;
 
        if (!strlen(class_dev->class_id))
-               goto register_done;
+               goto out1;
 
        parent_class = class_get(class_dev->class);
        if (!parent_class)
-               goto register_done;
+               goto out1;
+
        parent_class_dev = class_device_get(class_dev->parent);
 
        pr_debug("CLASS: registering class device: ID = '%s'\n",
                 class_dev->class_id);
 
        /* first, register with generic layer. */
-       kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
+       error = kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
+       if (error)
+               goto out2;
+
        if (parent_class_dev)
                class_dev->kobj.parent = &parent_class_dev->kobj;
        else
-               class_dev->kobj.parent = &parent_class->subsys.kset.kobj;
+               class_dev->kobj.parent = &parent_class->subsys.kobj;
 
        error = kobject_add(&class_dev->kobj);
        if (error)
-               goto register_done;
+               goto out2;
 
        /* add the needed attributes to this device */
-       class_dev->uevent_attr.attr.name = "uevent";
-       class_dev->uevent_attr.attr.mode = S_IWUSR;
-       class_dev->uevent_attr.attr.owner = parent_class->owner;
-       class_dev->uevent_attr.store = store_uevent;
-       class_device_create_file(class_dev, &class_dev->uevent_attr);
+       error = sysfs_create_link(&class_dev->kobj,
+                                 &parent_class->subsys.kobj, "subsystem");
+       if (error)
+               goto out3;
+
+       error = class_device_create_file(class_dev, &class_uevent_attr);
+       if (error)
+               goto out3;
 
        if (MAJOR(class_dev->devt)) {
-               struct class_device_attribute *attr;
-               attr = kzalloc(sizeof(*attr), GFP_KERNEL);
-               if (!attr) {
-                       error = -ENOMEM;
-                       kobject_del(&class_dev->kobj);
-                       goto register_done;
-               }
-               attr->attr.name = "dev";
-               attr->attr.mode = S_IRUGO;
-               attr->attr.owner = parent_class->owner;
-               attr->show = show_dev;
-               class_device_create_file(class_dev, attr);
-               class_dev->devt_attr = attr;
+               error = class_device_create_file(class_dev, &class_devt_attr);
+               if (error)
+                       goto out4;
        }
 
-       class_device_add_attrs(class_dev);
+       error = class_device_add_attrs(class_dev);
+       if (error)
+               goto out5;
+
        if (class_dev->dev) {
-               class_name = make_class_name(class_dev);
-               sysfs_create_link(&class_dev->kobj,
-                                 &class_dev->dev->kobj, "device");
-               sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
-                                 class_name);
+               error = sysfs_create_link(&class_dev->kobj,
+                                         &class_dev->dev->kobj, "device");
+               if (error)
+                       goto out6;
        }
 
-       kobject_hotplug(&class_dev->kobj, KOBJ_ADD);
+       error = class_device_add_groups(class_dev);
+       if (error)
+               goto out7;
+
+       error = make_deprecated_class_device_links(class_dev);
+       if (error)
+               goto out8;
+
+       kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 
        /* notify any interfaces this device is now here */
-       if (parent_class) {
-               down(&parent_class->sem);
-               list_add_tail(&class_dev->node, &parent_class->children);
-               list_for_each_entry(class_intf, &parent_class->interfaces, node)
-                       if (class_intf->add)
-                               class_intf->add(class_dev, class_intf);
-               up(&parent_class->sem);
+       down(&parent_class->sem);
+       list_add_tail(&class_dev->node, &parent_class->children);
+       list_for_each_entry(class_intf, &parent_class->interfaces, node) {
+               if (class_intf->add)
+                       class_intf->add(class_dev, class_intf);
        }
+       up(&parent_class->sem);
 
- register_done:
-       if (error) {
-               class_put(parent_class);
+       goto out1;
+
+ out8:
+       class_device_remove_groups(class_dev);
+ out7:
+       if (class_dev->dev)
+               sysfs_remove_link(&class_dev->kobj, "device");
+ out6:
+       class_device_remove_attrs(class_dev);
+ out5:
+       if (MAJOR(class_dev->devt))
+               class_device_remove_file(class_dev, &class_devt_attr);
+ out4:
+       class_device_remove_file(class_dev, &class_uevent_attr);
+ out3:
+       kobject_del(&class_dev->kobj);
+ out2:
+       if(parent_class_dev)
                class_device_put(parent_class_dev);
-       }
+       class_put(parent_class);
+ out1:
        class_device_put(class_dev);
-       kfree(class_name);
        return error;
 }
 
@@ -588,9 +680,9 @@ int class_device_register(struct class_device *class_dev)
 
 /**
  * class_device_create - creates a class device and registers it with sysfs
- * @cs: pointer to the struct class that this device should be registered to.
+ * @cls: pointer to the struct class that this device should be registered to.
  * @parent: pointer to the parent struct class_device of this new device, if any.
- * @dev: the dev_t for the char device to be added.
+ * @devt: the dev_t for the char device to be added.
  * @device: a pointer to a struct device that is assiociated with this class device.
  * @fmt: string for the class device's name
  *
@@ -611,7 +703,8 @@ int class_device_register(struct class_device *class_dev)
 struct class_device *class_device_create(struct class *cls,
                                         struct class_device *parent,
                                         dev_t devt,
-                                        struct device *device, char *fmt, ...)
+                                        struct device *device,
+                                        const char *fmt, ...)
 {
        va_list args;
        struct class_device *class_dev = NULL;
@@ -631,7 +724,7 @@ struct class_device *class_device_create(struct class *cls,
        class_dev->class = cls;
        class_dev->parent = parent;
        class_dev->release = class_device_create_release;
-       class_dev->hotplug = class_device_create_hotplug;
+       class_dev->uevent = class_device_create_uevent;
 
        va_start(args, fmt);
        vsnprintf(class_dev->class_id, BUS_ID_SIZE, fmt, args);
@@ -652,7 +745,6 @@ void class_device_del(struct class_device *class_dev)
        struct class *parent_class = class_dev->class;
        struct class_device *parent_device = class_dev->parent;
        struct class_interface *class_intf;
-       char *class_name = NULL;
 
        if (parent_class) {
                down(&parent_class->sem);
@@ -664,21 +756,21 @@ void class_device_del(struct class_device *class_dev)
        }
 
        if (class_dev->dev) {
-               class_name = make_class_name(class_dev);
+               remove_deprecated_class_device_links(class_dev);
                sysfs_remove_link(&class_dev->kobj, "device");
-               sysfs_remove_link(&class_dev->dev->kobj, class_name);
        }
-       class_device_remove_file(class_dev, &class_dev->uevent_attr);
-       if (class_dev->devt_attr)
-               class_device_remove_file(class_dev, class_dev->devt_attr);
+       sysfs_remove_link(&class_dev->kobj, "subsystem");
+       class_device_remove_file(class_dev, &class_uevent_attr);
+       if (MAJOR(class_dev->devt))
+               class_device_remove_file(class_dev, &class_devt_attr);
        class_device_remove_attrs(class_dev);
+       class_device_remove_groups(class_dev);
 
-       kobject_hotplug(&class_dev->kobj, KOBJ_REMOVE);
+       kobject_uevent(&class_dev->kobj, KOBJ_REMOVE);
        kobject_del(&class_dev->kobj);
 
        class_device_put(parent_device);
        class_put(parent_class);
-       kfree(class_name);
 }
 
 void class_device_unregister(struct class_device *class_dev)
@@ -692,7 +784,7 @@ void class_device_unregister(struct class_device *class_dev)
 /**
  * class_device_destroy - removes a class device that was created with class_device_create()
  * @cls: the pointer to the struct class that this device was registered * with.
- * @dev: the dev_t of the device that was previously registered.
+ * @devt: the dev_t of the device that was previously registered.
  *
  * This call unregisters and cleans up a class device that was created with a
  * call to class_device_create()
@@ -715,39 +807,6 @@ void class_device_destroy(struct class *cls, dev_t devt)
                class_device_unregister(class_dev);
 }
 
-int class_device_rename(struct class_device *class_dev, char *new_name)
-{
-       int error = 0;
-       char *old_class_name = NULL, *new_class_name = NULL;
-
-       class_dev = class_device_get(class_dev);
-       if (!class_dev)
-               return -EINVAL;
-
-       pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
-                new_name);
-
-       if (class_dev->dev)
-               old_class_name = make_class_name(class_dev);
-
-       strlcpy(class_dev->class_id, new_name, KOBJ_NAME_LEN);
-
-       error = kobject_rename(&class_dev->kobj, new_name);
-
-       if (class_dev->dev) {
-               new_class_name = make_class_name(class_dev);
-               sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
-                                 new_class_name);
-               sysfs_remove_link(&class_dev->dev->kobj, old_class_name);
-       }
-       class_device_put(class_dev);
-
-       kfree(old_class_name);
-       kfree(new_class_name);
-
-       return error;
-}
-
 struct class_device * class_device_get(struct class_device *class_dev)
 {
        if (class_dev)
@@ -766,6 +825,7 @@ int class_interface_register(struct class_interface *class_intf)
 {
        struct class *parent;
        struct class_device *class_dev;
+       struct device *dev;
 
        if (!class_intf || !class_intf->class)
                return -ENODEV;
@@ -780,6 +840,10 @@ int class_interface_register(struct class_interface *class_intf)
                list_for_each_entry(class_dev, &parent->children, node)
                        class_intf->add(class_dev, class_intf);
        }
+       if (class_intf->add_dev) {
+               list_for_each_entry(dev, &parent->devices, node)
+                       class_intf->add_dev(dev, class_intf);
+       }
        up(&parent->sem);
 
        return 0;
@@ -789,6 +853,7 @@ void class_interface_unregister(struct class_interface *class_intf)
 {
        struct class * parent = class_intf->class;
        struct class_device *class_dev;
+       struct device *dev;
 
        if (!parent)
                return;
@@ -799,13 +864,15 @@ void class_interface_unregister(struct class_interface *class_intf)
                list_for_each_entry(class_dev, &parent->children, node)
                        class_intf->remove(class_dev, class_intf);
        }
+       if (class_intf->remove_dev) {
+               list_for_each_entry(dev, &parent->devices, node)
+                       class_intf->remove_dev(dev, class_intf);
+       }
        up(&parent->sem);
 
        class_put(parent);
 }
 
-
-
 int __init classes_init(void)
 {
        int retval;
@@ -817,8 +884,8 @@ int __init classes_init(void)
        /* ick, this is ugly, the things we go through to keep from showing up
         * in sysfs... */
        subsystem_init(&class_obj_subsys);
-       if (!class_obj_subsys.kset.subsys)
-                       class_obj_subsys.kset.subsys = &class_obj_subsys;
+       if (!class_obj_subsys.kobj.parent)
+               class_obj_subsys.kobj.parent = &class_obj_subsys.kobj;
        return 0;
 }
 
@@ -826,8 +893,6 @@ EXPORT_SYMBOL_GPL(class_create_file);
 EXPORT_SYMBOL_GPL(class_remove_file);
 EXPORT_SYMBOL_GPL(class_register);
 EXPORT_SYMBOL_GPL(class_unregister);
-EXPORT_SYMBOL_GPL(class_get);
-EXPORT_SYMBOL_GPL(class_put);
 EXPORT_SYMBOL_GPL(class_create);
 EXPORT_SYMBOL_GPL(class_destroy);