Driver Core: add nodename callbacks
[safe/jmp/linux-2.6] / drivers / base / core.c
index 79848e6..7ecb193 100644 (file)
 #include <linux/notifier.h>
 #include <linux/genhd.h>
 #include <linux/kallsyms.h>
-#include <asm/semaphore.h>
+#include <linux/semaphore.h>
+#include <linux/mutex.h>
+#include <linux/async.h>
 
 #include "base.h"
 #include "power/power.h"
 
 int (*platform_notify)(struct device *dev) = NULL;
 int (*platform_notify_remove)(struct device *dev) = NULL;
+static struct kobject *dev_kobj;
+struct kobject *sysfs_dev_char_kobj;
+struct kobject *sysfs_dev_block_kobj;
 
 #ifdef CONFIG_BLOCK
 static inline int device_is_not_partition(struct device *dev)
@@ -49,7 +54,7 @@ static inline int device_is_not_partition(struct device *dev)
  * it is attached to.  If it is not attached to a bus either, an empty
  * string will be returned.
  */
-const char *dev_driver_string(struct device *dev)
+const char *dev_driver_string(const struct device *dev)
 {
        return dev->driver ? dev->driver->name :
                        (dev->bus ? dev->bus->name :
@@ -105,6 +110,7 @@ static struct sysfs_ops dev_sysfs_ops = {
 static void device_release(struct kobject *kobj)
 {
        struct device *dev = to_dev(kobj);
+       struct device_private *p = dev->p;
 
        if (dev->release)
                dev->release(dev);
@@ -112,12 +118,11 @@ static void device_release(struct kobject *kobj)
                dev->type->release(dev);
        else if (dev->class && dev->class->dev_release)
                dev->class->dev_release(dev);
-       else {
-               printk(KERN_ERR "Device '%s' does not have a release() "
+       else
+               WARN(1, KERN_ERR "Device '%s' does not have a release() "
                        "function, it is broken and must be fixed.\n",
-                       dev->bus_id);
-               WARN_ON(1);
-       }
+                       dev_name(dev));
+       kfree(p);
 }
 
 static struct kobj_type device_ktype = {
@@ -132,8 +137,6 @@ static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
 
        if (ktype == &device_ktype) {
                struct device *dev = to_dev(kobj);
-               if (dev->uevent_suppress)
-                       return 0;
                if (dev->bus)
                        return 1;
                if (dev->class)
@@ -159,10 +162,18 @@ static int dev_uevent(struct kset *kset, struct kobject *kobj,
        struct device *dev = to_dev(kobj);
        int retval = 0;
 
-       /* add the major/minor if present */
+       /* add device node properties if present */
        if (MAJOR(dev->devt)) {
+               const char *tmp;
+               const char *name;
+
                add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
                add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
+               name = device_get_nodename(dev, &tmp);
+               if (name) {
+                       add_uevent_var(env, "DEVNAME=%s", name);
+                       kfree(tmp);
+               }
        }
 
        if (dev->type && dev->type->name)
@@ -207,7 +218,7 @@ static int dev_uevent(struct kset *kset, struct kobject *kobj,
                retval = dev->bus->uevent(dev, env);
                if (retval)
                        pr_debug("device: '%s': %s: bus uevent() returned %d\n",
-                                dev->bus_id, __FUNCTION__, retval);
+                                dev_name(dev), __func__, retval);
        }
 
        /* have the class specific function add its stuff */
@@ -215,8 +226,8 @@ static int dev_uevent(struct kset *kset, struct kobject *kobj,
                retval = dev->class->dev_uevent(dev, env);
                if (retval)
                        pr_debug("device: '%s': %s: class uevent() "
-                                "returned %d\n", dev->bus_id,
-                                __FUNCTION__, retval);
+                                "returned %d\n", dev_name(dev),
+                                __func__, retval);
        }
 
        /* have the device type specific fuction add its stuff */
@@ -224,8 +235,8 @@ static int dev_uevent(struct kset *kset, struct kobject *kobj,
                retval = dev->type->uevent(dev, env);
                if (retval)
                        pr_debug("device: '%s': %s: dev_type uevent() "
-                                "returned %d\n", dev->bus_id,
-                                __FUNCTION__, retval);
+                                "returned %d\n", dev_name(dev),
+                                __func__, retval);
        }
 
        return retval;
@@ -505,14 +516,16 @@ EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
 
 static void klist_children_get(struct klist_node *n)
 {
-       struct device *dev = container_of(n, struct device, knode_parent);
+       struct device_private *p = to_device_private_parent(n);
+       struct device *dev = p->device;
 
        get_device(dev);
 }
 
 static void klist_children_put(struct klist_node *n)
 {
-       struct device *dev = container_of(n, struct device, knode_parent);
+       struct device_private *p = to_device_private_parent(n);
+       struct device *dev = p->device;
 
        put_device(dev);
 }
@@ -521,24 +534,27 @@ static void klist_children_put(struct klist_node *n)
  * device_initialize - init device structure.
  * @dev: device.
  *
- * This prepares the device for use by other layers,
- * including adding it to the device hierarchy.
+ * This prepares the device for use by other layers by initializing
+ * its fields.
  * It is the first half of device_register(), if called by
- * that, though it can also be called separately, so one
- * may use @dev's fields (e.g. the refcount).
+ * that function, though it can also be called separately, so one
+ * may use @dev's fields. In particular, get_device()/put_device()
+ * may be used for reference counting of @dev after calling this
+ * function.
+ *
+ * NOTE: Use put_device() to give up your reference instead of freeing
+ * @dev directly once you have called this function.
  */
 void device_initialize(struct device *dev)
 {
        dev->kobj.kset = devices_kset;
        kobject_init(&dev->kobj, &device_ktype);
-       klist_init(&dev->klist_children, klist_children_get,
-                  klist_children_put);
        INIT_LIST_HEAD(&dev->dma_pools);
-       INIT_LIST_HEAD(&dev->node);
        init_MUTEX(&dev->sem);
        spin_lock_init(&dev->devres_lock);
        INIT_LIST_HEAD(&dev->devres_head);
        device_init_wakeup(dev, 0);
+       device_pm_init(dev);
        set_dev_node(dev, -1);
 }
 
@@ -548,7 +564,7 @@ static struct kobject *get_device_parent(struct device *dev,
 {
        /* class devices without a parent live in /sys/class/<classname>/ */
        if (dev->class && (!parent || parent->class != dev->class))
-               return &dev->class->subsys.kobj;
+               return &dev->class->p->class_subsys.kobj;
        /* all other devices keep their parent */
        else if (parent)
                return &parent->kobj;
@@ -594,13 +610,13 @@ static struct kobject *get_device_parent(struct device *dev,
                        parent_kobj = &parent->kobj;
 
                /* find our class-directory at the parent and reference it */
-               spin_lock(&dev->class->class_dirs.list_lock);
-               list_for_each_entry(k, &dev->class->class_dirs.list, entry)
+               spin_lock(&dev->class->p->class_dirs.list_lock);
+               list_for_each_entry(k, &dev->class->p->class_dirs.list, entry)
                        if (k->parent == parent_kobj) {
                                kobj = kobject_get(k);
                                break;
                        }
-               spin_unlock(&dev->class->class_dirs.list_lock);
+               spin_unlock(&dev->class->p->class_dirs.list_lock);
                if (kobj)
                        return kobj;
 
@@ -608,7 +624,7 @@ static struct kobject *get_device_parent(struct device *dev,
                k = kobject_create();
                if (!k)
                        return NULL;
-               k->kset = &dev->class->class_dirs;
+               k->kset = &dev->class->p->class_dirs;
                retval = kobject_add(k, parent_kobj, "%s", dev->class->name);
                if (retval < 0) {
                        kobject_put(k);
@@ -627,7 +643,7 @@ static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
 {
        /* see if we live in a "glue" directory */
        if (!glue_dir || !dev->class ||
-           glue_dir->kset != &dev->class->class_dirs)
+           glue_dir->kset != &dev->class->p->class_dirs)
                return;
 
        kobject_put(glue_dir);
@@ -654,17 +670,18 @@ static int device_add_class_symlinks(struct device *dev)
        if (!dev->class)
                return 0;
 
-       error = sysfs_create_link(&dev->kobj, &dev->class->subsys.kobj,
+       error = sysfs_create_link(&dev->kobj,
+                                 &dev->class->p->class_subsys.kobj,
                                  "subsystem");
        if (error)
                goto out;
 
 #ifdef CONFIG_SYSFS_DEPRECATED
        /* stacked class devices need a symlink in the class directory */
-       if (dev->kobj.parent != &dev->class->subsys.kobj &&
+       if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
            device_is_not_partition(dev)) {
-               error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
-                                         dev->bus_id);
+               error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
+                                         &dev->kobj, dev_name(dev));
                if (error)
                        goto out_subsys;
        }
@@ -701,13 +718,14 @@ out_device:
        if (dev->parent && device_is_not_partition(dev))
                sysfs_remove_link(&dev->kobj, "device");
 out_busid:
-       if (dev->kobj.parent != &dev->class->subsys.kobj &&
+       if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
            device_is_not_partition(dev))
-               sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
+               sysfs_remove_link(&dev->class->p->class_subsys.kobj,
+                                 dev_name(dev));
 #else
        /* link in the class directory pointing to the device */
-       error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
-                                 dev->bus_id);
+       error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
+                                 &dev->kobj, dev_name(dev));
        if (error)
                goto out_subsys;
 
@@ -720,7 +738,7 @@ out_busid:
        return 0;
 
 out_busid:
-       sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
+       sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev_name(dev));
 #endif
 
 out_subsys:
@@ -746,49 +764,144 @@ static void device_remove_class_symlinks(struct device *dev)
                sysfs_remove_link(&dev->kobj, "device");
        }
 
-       if (dev->kobj.parent != &dev->class->subsys.kobj &&
+       if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
            device_is_not_partition(dev))
-               sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
+               sysfs_remove_link(&dev->class->p->class_subsys.kobj,
+                                 dev_name(dev));
 #else
        if (dev->parent && device_is_not_partition(dev))
                sysfs_remove_link(&dev->kobj, "device");
 
-       sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
+       sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev_name(dev));
 #endif
 
        sysfs_remove_link(&dev->kobj, "subsystem");
 }
 
 /**
+ * dev_set_name - set a device name
+ * @dev: device
+ * @fmt: format string for the device's name
+ */
+int dev_set_name(struct device *dev, const char *fmt, ...)
+{
+       va_list vargs;
+       int err;
+
+       va_start(vargs, fmt);
+       err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
+       va_end(vargs);
+       return err;
+}
+EXPORT_SYMBOL_GPL(dev_set_name);
+
+/**
+ * device_to_dev_kobj - select a /sys/dev/ directory for the device
+ * @dev: device
+ *
+ * By default we select char/ for new entries.  Setting class->dev_obj
+ * to NULL prevents an entry from being created.  class->dev_kobj must
+ * be set (or cleared) before any devices are registered to the class
+ * otherwise device_create_sys_dev_entry() and
+ * device_remove_sys_dev_entry() will disagree about the the presence
+ * of the link.
+ */
+static struct kobject *device_to_dev_kobj(struct device *dev)
+{
+       struct kobject *kobj;
+
+       if (dev->class)
+               kobj = dev->class->dev_kobj;
+       else
+               kobj = sysfs_dev_char_kobj;
+
+       return kobj;
+}
+
+static int device_create_sys_dev_entry(struct device *dev)
+{
+       struct kobject *kobj = device_to_dev_kobj(dev);
+       int error = 0;
+       char devt_str[15];
+
+       if (kobj) {
+               format_dev_t(devt_str, dev->devt);
+               error = sysfs_create_link(kobj, &dev->kobj, devt_str);
+       }
+
+       return error;
+}
+
+static void device_remove_sys_dev_entry(struct device *dev)
+{
+       struct kobject *kobj = device_to_dev_kobj(dev);
+       char devt_str[15];
+
+       if (kobj) {
+               format_dev_t(devt_str, dev->devt);
+               sysfs_remove_link(kobj, devt_str);
+       }
+}
+
+/**
  * device_add - add device to device hierarchy.
  * @dev: device.
  *
  * This is part 2 of device_register(), though may be called
  * separately _iff_ device_initialize() has been called separately.
  *
- * This adds it to the kobject hierarchy via kobject_add(), adds it
+ * This adds @dev to the kobject hierarchy via kobject_add(), adds it
  * to the global and sibling lists for the device, then
  * adds it to the other relevant subsystems of the driver model.
+ *
+ * NOTE: _Never_ directly free @dev after calling this function, even
+ * if it returned an error! Always use put_device() to give up your
+ * reference instead.
  */
 int device_add(struct device *dev)
 {
        struct device *parent = NULL;
        struct class_interface *class_intf;
-       int error;
+       int error = -EINVAL;
 
        dev = get_device(dev);
-       if (!dev || !strlen(dev->bus_id)) {
-               error = -EINVAL;
-               goto Done;
+       if (!dev)
+               goto done;
+
+       dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
+       if (!dev->p) {
+               error = -ENOMEM;
+               goto done;
+       }
+       dev->p->device = dev;
+       klist_init(&dev->p->klist_children, klist_children_get,
+                  klist_children_put);
+
+       /*
+        * for statically allocated devices, which should all be converted
+        * some day, we need to initialize the name. We prevent reading back
+        * the name, and force the use of dev_name()
+        */
+       if (dev->init_name) {
+               dev_set_name(dev, "%s", dev->init_name);
+               dev->init_name = NULL;
        }
 
-       pr_debug("device: '%s': %s\n", dev->bus_id, __FUNCTION__);
+       if (!dev_name(dev))
+               goto name_error;
+
+       pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
 
        parent = get_device(dev->parent);
        setup_parent(dev, parent);
 
+       /* use parent numa_node */
+       if (parent)
+               set_dev_node(dev, dev_to_node(parent));
+
        /* first, register with generic layer. */
-       error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev->bus_id);
+       /* we require the name to be set before, and pass NULL */
+       error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
        if (error)
                goto Error;
 
@@ -796,11 +909,6 @@ int device_add(struct device *dev)
        if (platform_notify)
                platform_notify(dev);
 
-       /* notify clients of device entry (new way) */
-       if (dev->bus)
-               blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
-                                            BUS_NOTIFY_ADD_DEVICE, dev);
-
        error = device_create_file(dev, &uevent_attr);
        if (error)
                goto attrError;
@@ -809,6 +917,10 @@ int device_add(struct device *dev)
                error = device_create_file(dev, &devt_attr);
                if (error)
                        goto ueventattrError;
+
+               error = device_create_sys_dev_entry(dev);
+               if (error)
+                       goto devtattrError;
        }
 
        error = device_add_class_symlinks(dev);
@@ -817,47 +929,54 @@ int device_add(struct device *dev)
        error = device_add_attrs(dev);
        if (error)
                goto AttrsError;
-       error = dpm_sysfs_add(dev);
-       if (error)
-               goto PMError;
-       error = device_pm_add(dev);
-       if (error) {
-               dpm_sysfs_remove(dev);
-               goto PMError;
-       }
        error = bus_add_device(dev);
        if (error)
                goto BusError;
+       error = dpm_sysfs_add(dev);
+       if (error)
+               goto DPMError;
+       device_pm_add(dev);
+
+       /* Notify clients of device addition.  This call must come
+        * after dpm_sysf_add() and before kobject_uevent().
+        */
+       if (dev->bus)
+               blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
+                                            BUS_NOTIFY_ADD_DEVICE, dev);
+
        kobject_uevent(&dev->kobj, KOBJ_ADD);
        bus_attach_device(dev);
        if (parent)
-               klist_add_tail(&dev->knode_parent, &parent->klist_children);
+               klist_add_tail(&dev->p->knode_parent,
+                              &parent->p->klist_children);
 
        if (dev->class) {
-               down(&dev->class->sem);
+               mutex_lock(&dev->class->p->class_mutex);
                /* tie the class to the device */
-               list_add_tail(&dev->node, &dev->class->devices);
+               klist_add_tail(&dev->knode_class,
+                              &dev->class->p->class_devices);
 
                /* notify any interfaces that the device is here */
-               list_for_each_entry(class_intf, &dev->class->interfaces, node)
+               list_for_each_entry(class_intf,
+                                   &dev->class->p->class_interfaces, node)
                        if (class_intf->add_dev)
                                class_intf->add_dev(dev, class_intf);
-               up(&dev->class->sem);
+               mutex_unlock(&dev->class->p->class_mutex);
        }
- Done:
+done:
        put_device(dev);
        return error;
+ DPMError:
+       bus_remove_device(dev);
  BusError:
-       device_pm_remove(dev);
- PMError:
-       if (dev->bus)
-               blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
-                                            BUS_NOTIFY_DEL_DEVICE, dev);
        device_remove_attrs(dev);
  AttrsError:
        device_remove_class_symlinks(dev);
  SymlinkError:
        if (MAJOR(dev->devt))
+               device_remove_sys_dev_entry(dev);
+ devtattrError:
+       if (MAJOR(dev->devt))
                device_remove_file(dev, &devt_attr);
  ueventattrError:
        device_remove_file(dev, &uevent_attr);
@@ -868,7 +987,10 @@ int device_add(struct device *dev)
        cleanup_device_parent(dev);
        if (parent)
                put_device(parent);
-       goto Done;
+name_error:
+       kfree(dev->p);
+       dev->p = NULL;
+       goto done;
 }
 
 /**
@@ -881,6 +1003,10 @@ int device_add(struct device *dev)
  * I.e. you should only call the two helpers separately if
  * have a clearly defined need to use and refcount the device
  * before it is added to the hierarchy.
+ *
+ * NOTE: _Never_ directly free @dev after calling this function, even
+ * if it returned an error! Always use put_device() to give up the
+ * reference initialized in this function instead.
  */
 int device_register(struct device *dev)
 {
@@ -930,22 +1056,32 @@ void device_del(struct device *dev)
        struct device *parent = dev->parent;
        struct class_interface *class_intf;
 
+       /* Notify clients of device removal.  This call must come
+        * before dpm_sysfs_remove().
+        */
+       if (dev->bus)
+               blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
+                                            BUS_NOTIFY_DEL_DEVICE, dev);
        device_pm_remove(dev);
+       dpm_sysfs_remove(dev);
        if (parent)
-               klist_del(&dev->knode_parent);
-       if (MAJOR(dev->devt))
+               klist_del(&dev->p->knode_parent);
+       if (MAJOR(dev->devt)) {
+               device_remove_sys_dev_entry(dev);
                device_remove_file(dev, &devt_attr);
+       }
        if (dev->class) {
                device_remove_class_symlinks(dev);
 
-               down(&dev->class->sem);
+               mutex_lock(&dev->class->p->class_mutex);
                /* notify any interfaces that the device is now gone */
-               list_for_each_entry(class_intf, &dev->class->interfaces, node)
+               list_for_each_entry(class_intf,
+                                   &dev->class->p->class_interfaces, node)
                        if (class_intf->remove_dev)
                                class_intf->remove_dev(dev, class_intf);
                /* remove the device from the class list */
-               list_del_init(&dev->node);
-               up(&dev->class->sem);
+               klist_del(&dev->knode_class);
+               mutex_unlock(&dev->class->p->class_mutex);
        }
        device_remove_file(dev, &uevent_attr);
        device_remove_attrs(dev);
@@ -963,9 +1099,6 @@ void device_del(struct device *dev)
         */
        if (platform_notify_remove)
                platform_notify_remove(dev);
-       if (dev->bus)
-               blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
-                                            BUS_NOTIFY_DEL_DEVICE, dev);
        kobject_uevent(&dev->kobj, KOBJ_REMOVE);
        cleanup_device_parent(dev);
        kobject_del(&dev->kobj);
@@ -985,7 +1118,7 @@ void device_del(struct device *dev)
  */
 void device_unregister(struct device *dev)
 {
-       pr_debug("device: '%s': %s\n", dev->bus_id, __FUNCTION__);
+       pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
        device_del(dev);
        put_device(dev);
 }
@@ -993,7 +1126,55 @@ void device_unregister(struct device *dev)
 static struct device *next_device(struct klist_iter *i)
 {
        struct klist_node *n = klist_next(i);
-       return n ? container_of(n, struct device, knode_parent) : NULL;
+       struct device *dev = NULL;
+       struct device_private *p;
+
+       if (n) {
+               p = to_device_private_parent(n);
+               dev = p->device;
+       }
+       return dev;
+}
+
+/**
+ * device_get_nodename - path of device node file
+ * @dev: device
+ * @tmp: possibly allocated string
+ *
+ * Return the relative path of a possible device node.
+ * Non-default names may need to allocate a memory to compose
+ * a name. This memory is returned in tmp and needs to be
+ * freed by the caller.
+ */
+const char *device_get_nodename(struct device *dev, const char **tmp)
+{
+       char *s;
+
+       *tmp = NULL;
+
+       /* the device type may provide a specific name */
+       if (dev->type && dev->type->nodename)
+               *tmp = dev->type->nodename(dev);
+       if (*tmp)
+               return *tmp;
+
+       /* the class may provide a specific name */
+       if (dev->class && dev->class->nodename)
+               *tmp = dev->class->nodename(dev);
+       if (*tmp)
+               return *tmp;
+
+       /* return name without allocation, tmp == NULL */
+       if (strchr(dev_name(dev), '!') == NULL)
+               return dev_name(dev);
+
+       /* replace '!' in the name with '/' */
+       *tmp = kstrdup(dev_name(dev), GFP_KERNEL);
+       if (!*tmp)
+               return NULL;
+       while ((s = strchr(*tmp, '!')))
+               s[0] = '/';
+       return *tmp;
 }
 
 /**
@@ -1015,7 +1196,10 @@ int device_for_each_child(struct device *parent, void *data,
        struct device *child;
        int error = 0;
 
-       klist_iter_init(&parent->klist_children, &i);
+       if (!parent->p)
+               return 0;
+
+       klist_iter_init(&parent->p->klist_children, &i);
        while ((child = next_device(&i)) && !error)
                error = fn(child, data);
        klist_iter_exit(&i);
@@ -1046,7 +1230,7 @@ struct device *device_find_child(struct device *parent, void *data,
        if (!parent)
                return NULL;
 
-       klist_iter_init(&parent->klist_children, &i);
+       klist_iter_init(&parent->p->klist_children, &i);
        while ((child = next_device(&i)))
                if (match(child, data) && get_device(child))
                        break;
@@ -1059,7 +1243,25 @@ int __init devices_init(void)
        devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
        if (!devices_kset)
                return -ENOMEM;
+       dev_kobj = kobject_create_and_add("dev", NULL);
+       if (!dev_kobj)
+               goto dev_kobj_err;
+       sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
+       if (!sysfs_dev_block_kobj)
+               goto block_kobj_err;
+       sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
+       if (!sysfs_dev_char_kobj)
+               goto char_kobj_err;
+
        return 0;
+
+ char_kobj_err:
+       kobject_put(sysfs_dev_block_kobj);
+ block_kobj_err:
+       kobject_put(dev_kobj);
+ dev_kobj_err:
+       kset_unregister(devices_kset);
+       return -ENOMEM;
 }
 
 EXPORT_SYMBOL_GPL(device_for_each_child);
@@ -1077,19 +1279,112 @@ EXPORT_SYMBOL_GPL(put_device);
 EXPORT_SYMBOL_GPL(device_create_file);
 EXPORT_SYMBOL_GPL(device_remove_file);
 
+struct root_device
+{
+       struct device dev;
+       struct module *owner;
+};
+
+#define to_root_device(dev) container_of(dev, struct root_device, dev)
+
+static void root_device_release(struct device *dev)
+{
+       kfree(to_root_device(dev));
+}
+
+/**
+ * __root_device_register - allocate and register a root device
+ * @name: root device name
+ * @owner: owner module of the root device, usually THIS_MODULE
+ *
+ * This function allocates a root device and registers it
+ * using device_register(). In order to free the returned
+ * device, use root_device_unregister().
+ *
+ * Root devices are dummy devices which allow other devices
+ * to be grouped under /sys/devices. Use this function to
+ * allocate a root device and then use it as the parent of
+ * any device which should appear under /sys/devices/{name}
+ *
+ * The /sys/devices/{name} directory will also contain a
+ * 'module' symlink which points to the @owner directory
+ * in sysfs.
+ *
+ * Note: You probably want to use root_device_register().
+ */
+struct device *__root_device_register(const char *name, struct module *owner)
+{
+       struct root_device *root;
+       int err = -ENOMEM;
+
+       root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
+       if (!root)
+               return ERR_PTR(err);
+
+       err = dev_set_name(&root->dev, "%s", name);
+       if (err) {
+               kfree(root);
+               return ERR_PTR(err);
+       }
+
+       root->dev.release = root_device_release;
+
+       err = device_register(&root->dev);
+       if (err) {
+               put_device(&root->dev);
+               return ERR_PTR(err);
+       }
+
+#ifdef CONFIG_MODULE   /* gotta find a "cleaner" way to do this */
+       if (owner) {
+               struct module_kobject *mk = &owner->mkobj;
+
+               err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
+               if (err) {
+                       device_unregister(&root->dev);
+                       return ERR_PTR(err);
+               }
+               root->owner = owner;
+       }
+#endif
+
+       return &root->dev;
+}
+EXPORT_SYMBOL_GPL(__root_device_register);
+
+/**
+ * root_device_unregister - unregister and free a root device
+ * @dev: device going away
+ *
+ * This function unregisters and cleans up a device that was created by
+ * root_device_register().
+ */
+void root_device_unregister(struct device *dev)
+{
+       struct root_device *root = to_root_device(dev);
+
+       if (root->owner)
+               sysfs_remove_link(&root->dev.kobj, "module");
+
+       device_unregister(dev);
+}
+EXPORT_SYMBOL_GPL(root_device_unregister);
+
 
 static void device_create_release(struct device *dev)
 {
-       pr_debug("device: '%s': %s\n", dev->bus_id, __FUNCTION__);
+       pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
        kfree(dev);
 }
 
 /**
- * device_create - creates a device and registers it with sysfs
+ * device_create_vargs - creates a device and registers it with sysfs
  * @class: pointer to the struct class that this device should be registered to
  * @parent: pointer to the parent struct device of this new device, if any
  * @devt: the dev_t for the char device to be added
+ * @drvdata: the data to be added to the device for callbacks
  * @fmt: string for the device's name
+ * @args: va_list for the device's name
  *
  * This function can be used by char device classes.  A struct device
  * will be created in sysfs, registered to the specified class.
@@ -1105,10 +1400,10 @@ static void device_create_release(struct device *dev)
  * Note: the struct class passed to this function must have previously
  * been created with a call to class_create().
  */
-struct device *device_create(struct class *class, struct device *parent,
-                            dev_t devt, const char *fmt, ...)
+struct device *device_create_vargs(struct class *class, struct device *parent,
+                                  dev_t devt, void *drvdata, const char *fmt,
+                                  va_list args)
 {
-       va_list args;
        struct device *dev = NULL;
        int retval = -ENODEV;
 
@@ -1125,10 +1420,12 @@ struct device *device_create(struct class *class, struct device *parent,
        dev->class = class;
        dev->parent = parent;
        dev->release = device_create_release;
+       dev_set_drvdata(dev, drvdata);
+
+       retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
+       if (retval)
+               goto error;
 
-       va_start(args, fmt);
-       vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
-       va_end(args);
        retval = device_register(dev);
        if (retval)
                goto error;
@@ -1136,9 +1433,44 @@ struct device *device_create(struct class *class, struct device *parent,
        return dev;
 
 error:
-       kfree(dev);
+       put_device(dev);
        return ERR_PTR(retval);
 }
+EXPORT_SYMBOL_GPL(device_create_vargs);
+
+/**
+ * device_create - creates a device and registers it with sysfs
+ * @class: pointer to the struct class that this device should be registered to
+ * @parent: pointer to the parent struct device of this new device, if any
+ * @devt: the dev_t for the char device to be added
+ * @drvdata: the data to be added to the device for callbacks
+ * @fmt: string for the device's name
+ *
+ * This function can be used by char device classes.  A struct device
+ * will be created in sysfs, registered to the specified class.
+ *
+ * A "dev" file will be created, showing the dev_t for the device, if
+ * the dev_t is not 0,0.
+ * If a pointer to a parent struct device is passed in, the newly created
+ * struct device will be a child of that device in sysfs.
+ * The pointer to the struct device will be returned from the call.
+ * Any further sysfs files that might be required can be created using this
+ * pointer.
+ *
+ * Note: the struct class passed to this function must have previously
+ * been created with a call to class_create().
+ */
+struct device *device_create(struct class *class, struct device *parent,
+                            dev_t devt, void *drvdata, const char *fmt, ...)
+{
+       va_list vargs;
+       struct device *dev;
+
+       va_start(vargs, fmt);
+       dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
+       va_end(vargs);
+       return dev;
+}
 EXPORT_SYMBOL_GPL(device_create);
 
 static int __match_devt(struct device *dev, void *data)
@@ -1160,7 +1492,7 @@ void device_destroy(struct class *class, dev_t devt)
 {
        struct device *dev;
 
-       dev = class_find_device(class, &devt, __match_devt);
+       dev = class_find_device(class, NULL, &devt, __match_devt);
        if (dev) {
                put_device(dev);
                device_unregister(dev);
@@ -1168,39 +1500,15 @@ void device_destroy(struct class *class, dev_t devt)
 }
 EXPORT_SYMBOL_GPL(device_destroy);
 
-#ifdef CONFIG_PM_SLEEP
-/**
- * destroy_suspended_device - asks the PM core to remove a suspended device
- * @class: pointer to the struct class that this device was registered with
- * @devt: the dev_t of the device that was previously registered
- *
- * This call notifies the PM core of the necessity to unregister a suspended
- * device created with a call to device_create() (devices cannot be
- * unregistered directly while suspended, since the PM core holds their
- * semaphores at that time).
- *
- * It can only be called within the scope of a system sleep transition.  In
- * practice this means it has to be directly or indirectly invoked either by
- * a suspend or resume method, or by the PM core (e.g. via
- * disable_nonboot_cpus() or enable_nonboot_cpus()).
- */
-void destroy_suspended_device(struct class *class, dev_t devt)
-{
-       struct device *dev;
-
-       dev = class_find_device(class, &devt, __match_devt);
-       if (dev) {
-               device_pm_schedule_removal(dev);
-               put_device(dev);
-       }
-}
-EXPORT_SYMBOL_GPL(destroy_suspended_device);
-#endif /* CONFIG_PM_SLEEP */
-
 /**
  * device_rename - renames a device
  * @dev: the pointer to the struct device to be renamed
  * @new_name: the new name of the device
+ *
+ * It is the responsibility of the caller to provide mutual
+ * exclusion between two different calls of device_rename
+ * on the same device to ensure that new_name is valid and
+ * won't conflict with other devices.
  */
 int device_rename(struct device *dev, char *new_name)
 {
@@ -1213,34 +1521,31 @@ int device_rename(struct device *dev, char *new_name)
        if (!dev)
                return -EINVAL;
 
-       pr_debug("device: '%s': %s: renaming to '%s'\n", dev->bus_id,
-                __FUNCTION__, new_name);
+       pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev),
+                __func__, new_name);
 
 #ifdef CONFIG_SYSFS_DEPRECATED
        if ((dev->class) && (dev->parent))
                old_class_name = make_class_name(dev->class->name, &dev->kobj);
 #endif
 
-       old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
+       old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
        if (!old_device_name) {
                error = -ENOMEM;
                goto out;
        }
-       strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
-       strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
 
        error = kobject_rename(&dev->kobj, new_name);
-       if (error) {
-               strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
+       if (error)
                goto out;
-       }
 
 #ifdef CONFIG_SYSFS_DEPRECATED
        if (old_class_name) {
                new_class_name = make_class_name(dev->class->name, &dev->kobj);
                if (new_class_name) {
-                       error = sysfs_create_link(&dev->parent->kobj,
-                                                 &dev->kobj, new_class_name);
+                       error = sysfs_create_link_nowarn(&dev->parent->kobj,
+                                                        &dev->kobj,
+                                                        new_class_name);
                        if (error)
                                goto out;
                        sysfs_remove_link(&dev->parent->kobj, old_class_name);
@@ -1248,13 +1553,12 @@ int device_rename(struct device *dev, char *new_name)
        }
 #else
        if (dev->class) {
-               sysfs_remove_link(&dev->class->subsys.kobj, old_device_name);
-               error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
-                                         dev->bus_id);
-               if (error) {
-                       dev_err(dev, "%s: sysfs_create_symlink failed (%d)\n",
-                               __FUNCTION__, error);
-               }
+               error = sysfs_create_link_nowarn(&dev->class->p->class_subsys.kobj,
+                                                &dev->kobj, dev_name(dev));
+               if (error)
+                       goto out;
+               sysfs_remove_link(&dev->class->p->class_subsys.kobj,
+                                 old_device_name);
        }
 #endif
 
@@ -1314,8 +1618,10 @@ out:
  * device_move - moves a device to a new parent
  * @dev: the pointer to the struct device to be moved
  * @new_parent: the new parent of the device (can by NULL)
+ * @dpm_order: how to reorder the dpm_list
  */
-int device_move(struct device *dev, struct device *new_parent)
+int device_move(struct device *dev, struct device *new_parent,
+               enum dpm_order dpm_order)
 {
        int error;
        struct device *old_parent;
@@ -1325,11 +1631,12 @@ int device_move(struct device *dev, struct device *new_parent)
        if (!dev)
                return -EINVAL;
 
+       device_pm_lock();
        new_parent = get_device(new_parent);
        new_parent_kobj = get_device_parent(dev, new_parent);
 
-       pr_debug("device: '%s': %s: moving to '%s'\n", dev->bus_id,
-                __FUNCTION__, new_parent ? new_parent->bus_id : "<NULL>");
+       pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
+                __func__, new_parent ? dev_name(new_parent) : "<NULL>");
        error = kobject_move(&dev->kobj, new_parent_kobj);
        if (error) {
                cleanup_glue_dir(dev, new_parent_kobj);
@@ -1339,9 +1646,13 @@ int device_move(struct device *dev, struct device *new_parent)
        old_parent = dev->parent;
        dev->parent = new_parent;
        if (old_parent)
-               klist_remove(&dev->knode_parent);
-       if (new_parent)
-               klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
+               klist_remove(&dev->p->knode_parent);
+       if (new_parent) {
+               klist_add_tail(&dev->p->knode_parent,
+                              &new_parent->p->klist_children);
+               set_dev_node(dev, dev_to_node(new_parent));
+       }
+
        if (!dev->class)
                goto out_put;
        error = device_move_class_links(dev, old_parent, new_parent);
@@ -1350,18 +1661,35 @@ int device_move(struct device *dev, struct device *new_parent)
                device_move_class_links(dev, new_parent, old_parent);
                if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
                        if (new_parent)
-                               klist_remove(&dev->knode_parent);
-                       if (old_parent)
-                               klist_add_tail(&dev->knode_parent,
-                                              &old_parent->klist_children);
+                               klist_remove(&dev->p->knode_parent);
+                       dev->parent = old_parent;
+                       if (old_parent) {
+                               klist_add_tail(&dev->p->knode_parent,
+                                              &old_parent->p->klist_children);
+                               set_dev_node(dev, dev_to_node(old_parent));
+                       }
                }
                cleanup_glue_dir(dev, new_parent_kobj);
                put_device(new_parent);
                goto out;
        }
+       switch (dpm_order) {
+       case DPM_ORDER_NONE:
+               break;
+       case DPM_ORDER_DEV_AFTER_PARENT:
+               device_pm_move_after(dev, new_parent);
+               break;
+       case DPM_ORDER_PARENT_BEFORE_DEV:
+               device_pm_move_before(new_parent, dev);
+               break;
+       case DPM_ORDER_DEV_LAST:
+               device_pm_move_last(dev);
+               break;
+       }
 out_put:
        put_device(old_parent);
 out:
+       device_pm_unlock();
        put_device(dev);
        return error;
 }
@@ -1384,4 +1712,8 @@ void device_shutdown(void)
                        dev->driver->shutdown(dev);
                }
        }
+       kobject_put(sysfs_dev_char_kobj);
+       kobject_put(sysfs_dev_block_kobj);
+       kobject_put(dev_kobj);
+       async_synchronize_full();
 }