1 files changed, 89 insertions, 64 deletions

diff --git a/drivers/base/class.c b/drivers/base/class.c
index e085af0ff94f..839d27cecb36 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -18,20 +18,20 @@
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/genhd.h>
+#include <linux/mutex.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.kobj)
 
 static ssize_t class_attr_show(struct kobject *kobj, struct attribute *attr,
                                char *buf)
 {
         struct class_attribute *class_attr = to_class_attr(attr);
-        struct class *dc = to_class(kobj);
+        struct class_private *cp = to_class(kobj);
         ssize_t ret = -EIO;
 
         if (class_attr->show)
-                ret = class_attr->show(dc, buf);
+                ret = class_attr->show(cp->class, buf);
         return ret;
 }
 
@@ -39,17 +39,18 @@ static ssize_t class_attr_store(struct kobject *kobj, struct attribute *attr,
                                 const char *buf, size_t count)
 {
         struct class_attribute *class_attr = to_class_attr(attr);
-        struct class *dc = to_class(kobj);
+        struct class_private *cp = to_class(kobj);
         ssize_t ret = -EIO;
 
         if (class_attr->store)
-                ret = class_attr->store(dc, buf, count);
+                ret = class_attr->store(cp->class, buf, count);
         return ret;
 }
 
 static void class_release(struct kobject *kobj)
 {
-        struct class *class = to_class(kobj);
+        struct class_private *cp = to_class(kobj);
+        struct class *class = cp->class;
 
         pr_debug("class '%s': release.\n", class->name);
 
@@ -70,7 +71,7 @@ static struct kobj_type class_ktype = {
         .release        = class_release,
 };
 
-/* Hotplug events for classes go to the class_obj subsys */
+/* Hotplug events for classes go to the class class_subsys */
 static struct kset *class_kset;
 
 
@@ -78,7 +79,8 @@ int class_create_file(struct class *cls, const struct class_attribute *attr)
 {
         int error;
         if (cls)
-                error = sysfs_create_file(&cls->subsys.kobj, &attr->attr);
+                error = sysfs_create_file(&cls->p->class_subsys.kobj,
+                                          &attr->attr);
         else
                 error = -EINVAL;
         return error;
@@ -87,21 +89,20 @@ 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.kobj, &attr->attr);
+                sysfs_remove_file(&cls->p->class_subsys.kobj, &attr->attr);
 }
 
 static struct class *class_get(struct class *cls)
 {
         if (cls)
-                return container_of(kset_get(&cls->subsys),
-                                    struct class, subsys);
-        return NULL;
+                kset_get(&cls->p->class_subsys);
+        return cls;
 }
 
 static void class_put(struct class *cls)
 {
         if (cls)
-                kset_put(&cls->subsys);
+                kset_put(&cls->p->class_subsys);
 }
 
 static int add_class_attrs(struct class *cls)
@@ -134,42 +135,57 @@ static void remove_class_attrs(struct class *cls)
         }
 }
 
-int class_register(struct class *cls)
+int __class_register(struct class *cls, struct lock_class_key *key)
 {
+        struct class_private *cp;
         int error;
 
         pr_debug("device class '%s': registering\n", cls->name);
 
-        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.kobj, "%s", cls->name);
-        if (error)
+        cp = kzalloc(sizeof(*cp), GFP_KERNEL);
+        if (!cp)
+                return -ENOMEM;
+        INIT_LIST_HEAD(&cp->class_devices);
+        INIT_LIST_HEAD(&cp->class_interfaces);
+        kset_init(&cp->class_dirs);
+        __mutex_init(&cp->class_mutex, "struct class mutex", key);
+        error = kobject_set_name(&cp->class_subsys.kobj, "%s", cls->name);
+        if (error) {
+                kfree(cp);
                 return error;
+        }
+
+        /* set the default /sys/dev directory for devices of this class */
+        if (!cls->dev_kobj)
+                cls->dev_kobj = sysfs_dev_char_kobj;
 
 #if defined(CONFIG_SYSFS_DEPRECATED) && defined(CONFIG_BLOCK)
         /* let the block class directory show up in the root of sysfs */
         if (cls != &block_class)
-                cls->subsys.kobj.kset = class_kset;
+                cp->class_subsys.kobj.kset = class_kset;
 #else
-        cls->subsys.kobj.kset = class_kset;
+        cp->class_subsys.kobj.kset = class_kset;
 #endif
-        cls->subsys.kobj.ktype = &class_ktype;
+        cp->class_subsys.kobj.ktype = &class_ktype;
+        cp->class = cls;
+        cls->p = cp;
 
-        error = kset_register(&cls->subsys);
-        if (!error) {
-                error = add_class_attrs(class_get(cls));
-                class_put(cls);
+        error = kset_register(&cp->class_subsys);
+        if (error) {
+                kfree(cp);
+                return error;
         }
+        error = add_class_attrs(class_get(cls));
+        class_put(cls);
         return error;
 }
+EXPORT_SYMBOL_GPL(__class_register);
 
 void class_unregister(struct class *cls)
 {
         pr_debug("device class '%s': unregistering\n", cls->name);
         remove_class_attrs(cls);
-        kset_unregister(&cls->subsys);
+        kset_unregister(&cls->p->class_subsys);
 }
 
 static void class_create_release(struct class *cls)
@@ -189,7 +205,8 @@ static void class_create_release(struct class *cls)
  * 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, const char *name)
+struct class *__class_create(struct module *owner, const char *name,
+                             struct lock_class_key *key)
 {
         struct class *cls;
         int retval;
@@ -204,7 +221,7 @@ struct class *class_create(struct module *owner, const char *name)
         cls->owner = owner;
         cls->class_release = class_create_release;
 
-        retval = class_register(cls);
+        retval = __class_register(cls, key);
         if (retval)
                 goto error;
 
@@ -214,6 +231,7 @@ error:
         kfree(cls);
         return ERR_PTR(retval);
 }
+EXPORT_SYMBOL_GPL(__class_create);
 
 /**
  * class_destroy - destroys a struct class structure
@@ -252,39 +270,44 @@ char *make_class_name(const char *name, struct kobject *kobj)
 /**
  * class_for_each_device - device iterator
  * @class: the class we're iterating
+ * @start: the device to start with in the list, if any.
  * @data: data for the callback
  * @fn: function to be called for each device
  *
  * Iterate over @class's list of devices, and call @fn for each,
- * passing it @data.
+ * passing it @data.  If @start is set, the list iteration will start
+ * there, otherwise if it is NULL, the iteration starts at the
+ * beginning of the list.
  *
  * We check the return of @fn each time. If it returns anything
  * other than 0, we break out and return that value.
  *
- * Note, we hold class->sem in this function, so it can not be
+ * Note, we hold class->class_mutex in this function, so it can not be
  * re-acquired in @fn, otherwise it will self-deadlocking. For
  * example, calls to add or remove class members would be verboten.
  */
-int class_for_each_device(struct class *class, void *data,
-                           int (*fn)(struct device *, void *))
+int class_for_each_device(struct class *class, struct device *start,
+                          void *data, int (*fn)(struct device *, void *))
 {
         struct device *dev;
         int error = 0;
 
         if (!class)
                 return -EINVAL;
-        down(&class->sem);
-        list_for_each_entry(dev, &class->devices, node) {
+        mutex_lock(&class->p->class_mutex);
+        list_for_each_entry(dev, &class->p->class_devices, node) {
+                if (start) {
+                        if (start == dev)
+                                start = NULL;
+                        continue;
+                }
                 dev = get_device(dev);
-                if (dev) {
-                        error = fn(dev, data);
-                        put_device(dev);
-                } else
-                        error = -ENODEV;
+                error = fn(dev, data);
+                put_device(dev);
                 if (error)
                         break;
         }
-        up(&class->sem);
+        mutex_unlock(&class->p->class_mutex);
 
         return error;
 }
@@ -293,6 +316,7 @@ EXPORT_SYMBOL_GPL(class_for_each_device);
 /**
  * class_find_device - device iterator for locating a particular device
  * @class: the class we're iterating
+ * @start: Device to begin with
  * @data: data for the match function
  * @match: function to check device
  *
@@ -306,12 +330,13 @@ EXPORT_SYMBOL_GPL(class_for_each_device);
  *
  * Note, you will need to drop the reference with put_device() after use.
  *
- * We hold class->sem in this function, so it can not be
+ * We hold class->class_mutex in this function, so it can not be
  * re-acquired in @match, otherwise it will self-deadlocking. For
  * example, calls to add or remove class members would be verboten.
  */
-struct device *class_find_device(struct class *class, void *data,
-                                   int (*match)(struct device *, void *))
+struct device *class_find_device(struct class *class, struct device *start,
+                                 void *data,
+                                 int (*match)(struct device *, void *))
 {
         struct device *dev;
         int found = 0;
@@ -319,19 +344,21 @@ struct device *class_find_device(struct class *class, void *data,
         if (!class)
                 return NULL;
 
-        down(&class->sem);
-        list_for_each_entry(dev, &class->devices, node) {
+        mutex_lock(&class->p->class_mutex);
+        list_for_each_entry(dev, &class->p->class_devices, node) {
+                if (start) {
+                        if (start == dev)
+                                start = NULL;
+                        continue;
+                }
                 dev = get_device(dev);
-                if (dev) {
-                        if (match(dev, data)) {
-                                found = 1;
-                                break;
-                        } else
-                                put_device(dev);
-                } else
+                if (match(dev, data)) {
+                        found = 1;
                         break;
+                } else
+                        put_device(dev);
         }
-        up(&class->sem);
+        mutex_unlock(&class->p->class_mutex);
 
         return found ? dev : NULL;
 }
@@ -349,13 +376,13 @@ int class_interface_register(struct class_interface *class_intf)
         if (!parent)
                 return -EINVAL;
 
-        down(&parent->sem);
-        list_add_tail(&class_intf->node, &parent->interfaces);
+        mutex_lock(&parent->p->class_mutex);
+        list_add_tail(&class_intf->node, &parent->p->class_interfaces);
         if (class_intf->add_dev) {
-                list_for_each_entry(dev, &parent->devices, node)
+                list_for_each_entry(dev, &parent->p->class_devices, node)
                         class_intf->add_dev(dev, class_intf);
         }
-        up(&parent->sem);
+        mutex_unlock(&parent->p->class_mutex);
 
         return 0;
 }
@@ -368,13 +395,13 @@ void class_interface_unregister(struct class_interface *class_intf)
         if (!parent)
                 return;
 
-        down(&parent->sem);
+        mutex_lock(&parent->p->class_mutex);
         list_del_init(&class_intf->node);
         if (class_intf->remove_dev) {
-                list_for_each_entry(dev, &parent->devices, node)
+                list_for_each_entry(dev, &parent->p->class_devices, node)
                         class_intf->remove_dev(dev, class_intf);
         }
-        up(&parent->sem);
+        mutex_unlock(&parent->p->class_mutex);
 
         class_put(parent);
 }
@@ -389,9 +416,7 @@ int __init classes_init(void)
 
 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_create);
 EXPORT_SYMBOL_GPL(class_destroy);
 
 EXPORT_SYMBOL_GPL(class_interface_register);