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-rw-r--r--drivers/base/class.c153
1 files changed, 89 insertions, 64 deletions
diff --git a/drivers/base/class.c b/drivers/base/class.c
index e085af0..839d27c 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);
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