regmap: Skip patch application when the cache is not dirty on sync
[linux-2.6.git] / drivers / base / class.c
index 48b518e..03243d4 100644 (file)
@@ -18,6 +18,7 @@
 #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)
@@ -26,11 +27,11 @@ 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_private *cp = to_class(kobj);
+       struct subsys_private *cp = to_subsys_private(kobj);
        ssize_t ret = -EIO;
 
        if (class_attr->show)
-               ret = class_attr->show(cp->class, buf);
+               ret = class_attr->show(cp->class, class_attr, buf);
        return ret;
 }
 
@@ -38,17 +39,29 @@ 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_private *cp = to_class(kobj);
+       struct subsys_private *cp = to_subsys_private(kobj);
        ssize_t ret = -EIO;
 
        if (class_attr->store)
-               ret = class_attr->store(cp->class, buf, count);
+               ret = class_attr->store(cp->class, class_attr, buf, count);
        return ret;
 }
 
+static const void *class_attr_namespace(struct kobject *kobj,
+                                       const struct attribute *attr)
+{
+       struct class_attribute *class_attr = to_class_attr(attr);
+       struct subsys_private *cp = to_subsys_private(kobj);
+       const void *ns = NULL;
+
+       if (class_attr->namespace)
+               ns = class_attr->namespace(cp->class, class_attr);
+       return ns;
+}
+
 static void class_release(struct kobject *kobj)
 {
-       struct class_private *cp = to_class(kobj);
+       struct subsys_private *cp = to_subsys_private(kobj);
        struct class *class = cp->class;
 
        pr_debug("class '%s': release.\n", class->name);
@@ -58,19 +71,31 @@ static void class_release(struct kobject *kobj)
        else
                pr_debug("class '%s' does not have a release() function, "
                         "be careful\n", class->name);
+
+       kfree(cp);
+}
+
+static const struct kobj_ns_type_operations *class_child_ns_type(struct kobject *kobj)
+{
+       struct subsys_private *cp = to_subsys_private(kobj);
+       struct class *class = cp->class;
+
+       return class->ns_type;
 }
 
-static struct sysfs_ops class_sysfs_ops = {
-       .show   = class_attr_show,
-       .store  = class_attr_store,
+static const struct sysfs_ops class_sysfs_ops = {
+       .show      = class_attr_show,
+       .store     = class_attr_store,
+       .namespace = class_attr_namespace,
 };
 
 static struct kobj_type class_ktype = {
        .sysfs_ops      = &class_sysfs_ops,
        .release        = class_release,
+       .child_ns_type  = class_child_ns_type,
 };
 
-/* Hotplug events for classes go to the class_obj subsys */
+/* Hotplug events for classes go to the class subsys */
 static struct kset *class_kset;
 
 
@@ -78,7 +103,8 @@ int class_create_file(struct class *cls, const struct class_attribute *attr)
 {
        int error;
        if (cls)
-               error = sysfs_create_file(&cls->p->subsys.kobj, &attr->attr);
+               error = sysfs_create_file(&cls->p->subsys.kobj,
+                                         &attr->attr);
        else
                error = -EINVAL;
        return error;
@@ -133,9 +159,23 @@ static void remove_class_attrs(struct class *cls)
        }
 }
 
-int class_register(struct class *cls)
+static void klist_class_dev_get(struct klist_node *n)
 {
-       struct class_private *cp;
+       struct device *dev = container_of(n, struct device, knode_class);
+
+       get_device(dev);
+}
+
+static void klist_class_dev_put(struct klist_node *n)
+{
+       struct device *dev = container_of(n, struct device, knode_class);
+
+       put_device(dev);
+}
+
+int __class_register(struct class *cls, struct lock_class_key *key)
+{
+       struct subsys_private *cp;
        int error;
 
        pr_debug("device class '%s': registering\n", cls->name);
@@ -143,10 +183,10 @@ int class_register(struct class *cls)
        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);
-       init_MUTEX(&cp->sem);
+       klist_init(&cp->klist_devices, klist_class_dev_get, klist_class_dev_put);
+       INIT_LIST_HEAD(&cp->interfaces);
+       kset_init(&cp->glue_dirs);
+       __mutex_init(&cp->mutex, "subsys mutex", key);
        error = kobject_set_name(&cp->subsys.kobj, "%s", cls->name);
        if (error) {
                kfree(cp);
@@ -157,9 +197,9 @@ int class_register(struct class *cls)
        if (!cls->dev_kobj)
                cls->dev_kobj = sysfs_dev_char_kobj;
 
-#if defined(CONFIG_SYSFS_DEPRECATED) && defined(CONFIG_BLOCK)
+#if defined(CONFIG_BLOCK)
        /* let the block class directory show up in the root of sysfs */
-       if (cls != &block_class)
+       if (!sysfs_deprecated || cls != &block_class)
                cp->subsys.kobj.kset = class_kset;
 #else
        cp->subsys.kobj.kset = class_kset;
@@ -177,6 +217,7 @@ int class_register(struct class *cls)
        class_put(cls);
        return error;
 }
+EXPORT_SYMBOL_GPL(__class_register);
 
 void class_unregister(struct class *cls)
 {
@@ -195,14 +236,18 @@ static void class_create_release(struct class *cls)
  * class_create - create a struct class structure
  * @owner: pointer to the module that is to "own" this struct class
  * @name: pointer to a string for the name of this class.
+ * @key: the lock_class_key for this class; used by mutex lock debugging
  *
  * This is used to create a struct class pointer that can then be used
  * in calls to device_create().
  *
+ * Returns &struct class pointer on success, or ERR_PTR() on error.
+ *
  * 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;
@@ -217,7 +262,7 @@ 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;
 
@@ -227,6 +272,7 @@ error:
        kfree(cls);
        return ERR_PTR(retval);
 }
+EXPORT_SYMBOL_GPL(__class_create);
 
 /**
  * class_destroy - destroys a struct class structure
@@ -243,24 +289,70 @@ void class_destroy(struct class *cls)
        class_unregister(cls);
 }
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-char *make_class_name(const char *name, struct kobject *kobj)
+/**
+ * class_dev_iter_init - initialize class device iterator
+ * @iter: class iterator to initialize
+ * @class: the class we wanna iterate over
+ * @start: the device to start iterating from, if any
+ * @type: device_type of the devices to iterate over, NULL for all
+ *
+ * Initialize class iterator @iter such that it iterates over devices
+ * of @class.  If @start is set, the list iteration will start there,
+ * otherwise if it is NULL, the iteration starts at the beginning of
+ * the list.
+ */
+void class_dev_iter_init(struct class_dev_iter *iter, struct class *class,
+                        struct device *start, const struct device_type *type)
 {
-       char *class_name;
-       int size;
+       struct klist_node *start_knode = NULL;
 
-       size = strlen(name) + strlen(kobject_name(kobj)) + 2;
+       if (start)
+               start_knode = &start->knode_class;
+       klist_iter_init_node(&class->p->klist_devices, &iter->ki, start_knode);
+       iter->type = type;
+}
+EXPORT_SYMBOL_GPL(class_dev_iter_init);
 
-       class_name = kmalloc(size, GFP_KERNEL);
-       if (!class_name)
-               return NULL;
+/**
+ * class_dev_iter_next - iterate to the next device
+ * @iter: class iterator to proceed
+ *
+ * Proceed @iter to the next device and return it.  Returns NULL if
+ * iteration is complete.
+ *
+ * The returned device is referenced and won't be released till
+ * iterator is proceed to the next device or exited.  The caller is
+ * free to do whatever it wants to do with the device including
+ * calling back into class code.
+ */
+struct device *class_dev_iter_next(struct class_dev_iter *iter)
+{
+       struct klist_node *knode;
+       struct device *dev;
 
-       strcpy(class_name, name);
-       strcat(class_name, ":");
-       strcat(class_name, kobject_name(kobj));
-       return class_name;
+       while (1) {
+               knode = klist_next(&iter->ki);
+               if (!knode)
+                       return NULL;
+               dev = container_of(knode, struct device, knode_class);
+               if (!iter->type || iter->type == dev->type)
+                       return dev;
+       }
 }
-#endif
+EXPORT_SYMBOL_GPL(class_dev_iter_next);
+
+/**
+ * class_dev_iter_exit - finish iteration
+ * @iter: class iterator to finish
+ *
+ * Finish an iteration.  Always call this function after iteration is
+ * complete whether the iteration ran till the end or not.
+ */
+void class_dev_iter_exit(struct class_dev_iter *iter)
+{
+       klist_iter_exit(&iter->ki);
+}
+EXPORT_SYMBOL_GPL(class_dev_iter_exit);
 
 /**
  * class_for_each_device - device iterator
@@ -277,32 +369,31 @@ char *make_class_name(const char *name, struct kobject *kobj)
  * 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
- * re-acquired in @fn, otherwise it will self-deadlocking. For
- * example, calls to add or remove class members would be verboten.
+ * @fn is allowed to do anything including calling back into class
+ * code.  There's no locking restriction.
  */
 int class_for_each_device(struct class *class, struct device *start,
                          void *data, int (*fn)(struct device *, void *))
 {
+       struct class_dev_iter iter;
        struct device *dev;
        int error = 0;
 
        if (!class)
                return -EINVAL;
-       down(&class->p->sem);
-       list_for_each_entry(dev, &class->p->class_devices, node) {
-               if (start) {
-                       if (start == dev)
-                               start = NULL;
-                       continue;
-               }
-               dev = get_device(dev);
+       if (!class->p) {
+               WARN(1, "%s called for class '%s' before it was initialized",
+                    __func__, class->name);
+               return -EINVAL;
+       }
+
+       class_dev_iter_init(&iter, class, start, NULL);
+       while ((dev = class_dev_iter_next(&iter))) {
                error = fn(dev, data);
-               put_device(dev);
                if (error)
                        break;
        }
-       up(&class->p->sem);
+       class_dev_iter_exit(&iter);
 
        return error;
 }
@@ -325,43 +416,41 @@ 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
- * re-acquired in @match, otherwise it will self-deadlocking. For
- * example, calls to add or remove class members would be verboten.
+ * @fn is allowed to do anything including calling back into class
+ * code.  There's no locking restriction.
  */
 struct device *class_find_device(struct class *class, struct device *start,
                                 void *data,
                                 int (*match)(struct device *, void *))
 {
+       struct class_dev_iter iter;
        struct device *dev;
-       int found = 0;
 
        if (!class)
                return NULL;
+       if (!class->p) {
+               WARN(1, "%s called for class '%s' before it was initialized",
+                    __func__, class->name);
+               return NULL;
+       }
 
-       down(&class->p->sem);
-       list_for_each_entry(dev, &class->p->class_devices, node) {
-               if (start) {
-                       if (start == dev)
-                               start = NULL;
-                       continue;
-               }
-               dev = get_device(dev);
+       class_dev_iter_init(&iter, class, start, NULL);
+       while ((dev = class_dev_iter_next(&iter))) {
                if (match(dev, data)) {
-                       found = 1;
+                       get_device(dev);
                        break;
-               } else
-                       put_device(dev);
+               }
        }
-       up(&class->p->sem);
+       class_dev_iter_exit(&iter);
 
-       return found ? dev : NULL;
+       return dev;
 }
 EXPORT_SYMBOL_GPL(class_find_device);
 
 int class_interface_register(struct class_interface *class_intf)
 {
        struct class *parent;
+       struct class_dev_iter iter;
        struct device *dev;
 
        if (!class_intf || !class_intf->class)
@@ -371,13 +460,15 @@ int class_interface_register(struct class_interface *class_intf)
        if (!parent)
                return -EINVAL;
 
-       down(&parent->p->sem);
-       list_add_tail(&class_intf->node, &parent->p->class_interfaces);
+       mutex_lock(&parent->p->mutex);
+       list_add_tail(&class_intf->node, &parent->p->interfaces);
        if (class_intf->add_dev) {
-               list_for_each_entry(dev, &parent->p->class_devices, node)
+               class_dev_iter_init(&iter, parent, NULL, NULL);
+               while ((dev = class_dev_iter_next(&iter)))
                        class_intf->add_dev(dev, class_intf);
+               class_dev_iter_exit(&iter);
        }
-       up(&parent->p->sem);
+       mutex_unlock(&parent->p->mutex);
 
        return 0;
 }
@@ -385,22 +476,122 @@ int class_interface_register(struct class_interface *class_intf)
 void class_interface_unregister(struct class_interface *class_intf)
 {
        struct class *parent = class_intf->class;
+       struct class_dev_iter iter;
        struct device *dev;
 
        if (!parent)
                return;
 
-       down(&parent->p->sem);
+       mutex_lock(&parent->p->mutex);
        list_del_init(&class_intf->node);
        if (class_intf->remove_dev) {
-               list_for_each_entry(dev, &parent->p->class_devices, node)
+               class_dev_iter_init(&iter, parent, NULL, NULL);
+               while ((dev = class_dev_iter_next(&iter)))
                        class_intf->remove_dev(dev, class_intf);
+               class_dev_iter_exit(&iter);
        }
-       up(&parent->p->sem);
+       mutex_unlock(&parent->p->mutex);
 
        class_put(parent);
 }
 
+ssize_t show_class_attr_string(struct class *class,
+                              struct class_attribute *attr, char *buf)
+{
+       struct class_attribute_string *cs;
+       cs = container_of(attr, struct class_attribute_string, attr);
+       return snprintf(buf, PAGE_SIZE, "%s\n", cs->str);
+}
+
+EXPORT_SYMBOL_GPL(show_class_attr_string);
+
+struct class_compat {
+       struct kobject *kobj;
+};
+
+/**
+ * class_compat_register - register a compatibility class
+ * @name: the name of the class
+ *
+ * Compatibility class are meant as a temporary user-space compatibility
+ * workaround when converting a family of class devices to a bus devices.
+ */
+struct class_compat *class_compat_register(const char *name)
+{
+       struct class_compat *cls;
+
+       cls = kmalloc(sizeof(struct class_compat), GFP_KERNEL);
+       if (!cls)
+               return NULL;
+       cls->kobj = kobject_create_and_add(name, &class_kset->kobj);
+       if (!cls->kobj) {
+               kfree(cls);
+               return NULL;
+       }
+       return cls;
+}
+EXPORT_SYMBOL_GPL(class_compat_register);
+
+/**
+ * class_compat_unregister - unregister a compatibility class
+ * @cls: the class to unregister
+ */
+void class_compat_unregister(struct class_compat *cls)
+{
+       kobject_put(cls->kobj);
+       kfree(cls);
+}
+EXPORT_SYMBOL_GPL(class_compat_unregister);
+
+/**
+ * class_compat_create_link - create a compatibility class device link to
+ *                           a bus device
+ * @cls: the compatibility class
+ * @dev: the target bus device
+ * @device_link: an optional device to which a "device" link should be created
+ */
+int class_compat_create_link(struct class_compat *cls, struct device *dev,
+                            struct device *device_link)
+{
+       int error;
+
+       error = sysfs_create_link(cls->kobj, &dev->kobj, dev_name(dev));
+       if (error)
+               return error;
+
+       /*
+        * Optionally add a "device" link (typically to the parent), as a
+        * class device would have one and we want to provide as much
+        * backwards compatibility as possible.
+        */
+       if (device_link) {
+               error = sysfs_create_link(&dev->kobj, &device_link->kobj,
+                                         "device");
+               if (error)
+                       sysfs_remove_link(cls->kobj, dev_name(dev));
+       }
+
+       return error;
+}
+EXPORT_SYMBOL_GPL(class_compat_create_link);
+
+/**
+ * class_compat_remove_link - remove a compatibility class device link to
+ *                           a bus device
+ * @cls: the compatibility class
+ * @dev: the target bus device
+ * @device_link: an optional device to which a "device" link was previously
+ *              created
+ */
+void class_compat_remove_link(struct class_compat *cls, struct device *dev,
+                             struct device *device_link)
+{
+       if (device_link)
+               sysfs_remove_link(&dev->kobj, "device");
+       sysfs_remove_link(cls->kobj, dev_name(dev));
+}
+EXPORT_SYMBOL_GPL(class_compat_remove_link);
+
 int __init classes_init(void)
 {
        class_kset = kset_create_and_add("class", NULL, NULL);
@@ -411,9 +602,7 @@ 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);