X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=drivers%2Fbase%2Fclass.c;h=161746deab4baabb00bebdf4fb0991bbdf693f7f;hb=b5f54b07c06f6e438a4fee92c27423e880d8816b;hp=48b518e66bfcb587fcd370ed7eff168793472395;hpb=184f1f779d5a2e62de4a0b34842ddf8546beca8f;p=safe%2Fjmp%2Flinux-2.6 diff --git a/drivers/base/class.c b/drivers/base/class.c index 48b518e..161746d 100644 --- a/drivers/base/class.c +++ b/drivers/base/class.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "base.h" #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr) @@ -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->p->subsys.kobj, &attr->attr); + error = sysfs_create_file(&cls->p->class_subsys.kobj, + &attr->attr); else error = -EINVAL; return error; @@ -87,20 +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->p->subsys.kobj, &attr->attr); + sysfs_remove_file(&cls->p->class_subsys.kobj, &attr->attr); } static struct class *class_get(struct class *cls) { if (cls) - kset_get(&cls->p->subsys); + kset_get(&cls->p->class_subsys); return cls; } static void class_put(struct class *cls) { if (cls) - kset_put(&cls->p->subsys); + kset_put(&cls->p->class_subsys); } static int add_class_attrs(struct class *cls) @@ -133,7 +135,21 @@ 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 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 class_private *cp; int error; @@ -143,11 +159,11 @@ int class_register(struct class *cls) cp = kzalloc(sizeof(*cp), GFP_KERNEL); if (!cp) return -ENOMEM; - INIT_LIST_HEAD(&cp->class_devices); + klist_init(&cp->class_devices, klist_class_dev_get, klist_class_dev_put); INIT_LIST_HEAD(&cp->class_interfaces); kset_init(&cp->class_dirs); - init_MUTEX(&cp->sem); - error = kobject_set_name(&cp->subsys.kobj, "%s", cls->name); + __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; @@ -160,15 +176,15 @@ int class_register(struct class *cls) #if defined(CONFIG_SYSFS_DEPRECATED) && defined(CONFIG_BLOCK) /* let the block class directory show up in the root of sysfs */ if (cls != &block_class) - cp->subsys.kobj.kset = class_kset; + cp->class_subsys.kobj.kset = class_kset; #else - cp->subsys.kobj.kset = class_kset; + cp->class_subsys.kobj.kset = class_kset; #endif - cp->subsys.kobj.ktype = &class_ktype; + cp->class_subsys.kobj.ktype = &class_ktype; cp->class = cls; cls->p = cp; - error = kset_register(&cp->subsys); + error = kset_register(&cp->class_subsys); if (error) { kfree(cp); return error; @@ -177,12 +193,13 @@ int class_register(struct class *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->p->subsys); + kset_unregister(&cls->p->class_subsys); } static void class_create_release(struct class *cls) @@ -195,6 +212,7 @@ 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(). @@ -202,7 +220,8 @@ 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; @@ -217,7 +236,7 @@ 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 +246,7 @@ error: kfree(cls); return ERR_PTR(retval); } +EXPORT_SYMBOL_GPL(__class_create); /** * class_destroy - destroys a struct class structure @@ -263,6 +283,71 @@ char *make_class_name(const char *name, struct kobject *kobj) #endif /** + * 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) +{ + struct klist_node *start_knode = NULL; + + if (start) + start_knode = &start->knode_class; + klist_iter_init_node(&class->p->class_devices, &iter->ki, start_knode); + iter->type = type; +} +EXPORT_SYMBOL_GPL(class_dev_iter_init); + +/** + * 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; + + 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; + } +} +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 * @class: the class we're iterating * @start: the device to start with in the list, if any. @@ -277,32 +362,31 @@ 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 +409,41 @@ 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 +453,15 @@ int class_interface_register(struct class_interface *class_intf) if (!parent) return -EINVAL; - down(&parent->p->sem); + 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->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->class_mutex); return 0; } @@ -385,22 +469,112 @@ 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->class_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->class_mutex); class_put(parent); } +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 +585,7 @@ 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);