Contributors: 34
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Greg Kroah-Hartman |
946 |
39.90% |
39 |
38.24% |
| Patrick Mochel |
360 |
15.18% |
19 |
18.63% |
| Tejun Heo |
307 |
12.95% |
2 |
1.96% |
| Jean Delvare |
263 |
11.09% |
1 |
0.98% |
| Yang Ruirui |
142 |
5.99% |
2 |
1.96% |
| Kay Sievers |
59 |
2.49% |
6 |
5.88% |
| Andi Kleen |
57 |
2.40% |
2 |
1.96% |
| David Brownell |
45 |
1.90% |
1 |
0.98% |
| Wei Yang |
33 |
1.39% |
1 |
0.98% |
| Eric W. Biedermann |
26 |
1.10% |
1 |
0.98% |
| Yang Yingliang |
25 |
1.05% |
2 |
1.96% |
| Leann Ogasawara |
16 |
0.67% |
1 |
0.98% |
| Matthew Wilcox |
15 |
0.63% |
2 |
1.96% |
| Linus Torvalds |
14 |
0.59% |
1 |
0.98% |
| Rafael J. Wysocki |
12 |
0.51% |
1 |
0.98% |
| Jing Xia |
5 |
0.21% |
1 |
0.98% |
| Laurent Pinchart |
5 |
0.21% |
1 |
0.98% |
| Jiri Slaby |
5 |
0.21% |
1 |
0.98% |
| Dmitry Torokhov |
4 |
0.17% |
1 |
0.98% |
| Cornelia Huck |
4 |
0.17% |
1 |
0.98% |
| Art Haas |
4 |
0.17% |
1 |
0.98% |
| Linus Torvalds (pre-git) |
3 |
0.13% |
2 |
1.96% |
| Maurizio Lombardi |
3 |
0.13% |
1 |
0.98% |
| Tim Schmielau |
3 |
0.13% |
1 |
0.98% |
| David S. Miller |
3 |
0.13% |
1 |
0.98% |
| Stephen Hemminger |
2 |
0.08% |
1 |
0.98% |
| Rolf Eike Beer |
2 |
0.08% |
2 |
1.96% |
| Michał Mirosław |
2 |
0.08% |
1 |
0.98% |
| Emese Revfy |
1 |
0.04% |
1 |
0.98% |
| Christoph Hellwig |
1 |
0.04% |
1 |
0.98% |
| Thomas Weißschuh |
1 |
0.04% |
1 |
0.98% |
| Joe Perches |
1 |
0.04% |
1 |
0.98% |
| Harvey Harrison |
1 |
0.04% |
1 |
0.98% |
| Miguel Ojeda Sandonis |
1 |
0.04% |
1 |
0.98% |
| Total |
2371 |
|
102 |
|
// SPDX-License-Identifier: GPL-2.0
/*
* class.c - basic device class management
*
* Copyright (c) 2002-3 Patrick Mochel
* Copyright (c) 2002-3 Open Source Development Labs
* Copyright (c) 2003-2004 Greg Kroah-Hartman
* Copyright (c) 2003-2004 IBM Corp.
*/
#include <linux/device/class.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/kdev_t.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/mutex.h>
#include "base.h"
/* /sys/class */
static struct kset *class_kset;
#define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
/**
* class_to_subsys - Turn a struct class into a struct subsys_private
*
* @class: pointer to the struct bus_type to look up
*
* The driver core internals need to work on the subsys_private structure, not
* the external struct class pointer. This function walks the list of
* registered classes in the system and finds the matching one and returns the
* internal struct subsys_private that relates to that class.
*
* Note, the reference count of the return value is INCREMENTED if it is not
* NULL. A call to subsys_put() must be done when finished with the pointer in
* order for it to be properly freed.
*/
struct subsys_private *class_to_subsys(const struct class *class)
{
struct subsys_private *sp = NULL;
struct kobject *kobj;
if (!class || !class_kset)
return NULL;
spin_lock(&class_kset->list_lock);
if (list_empty(&class_kset->list))
goto done;
list_for_each_entry(kobj, &class_kset->list, entry) {
struct kset *kset = container_of(kobj, struct kset, kobj);
sp = container_of_const(kset, struct subsys_private, subsys);
if (sp->class == class)
goto done;
}
sp = NULL;
done:
sp = subsys_get(sp);
spin_unlock(&class_kset->list_lock);
return sp;
}
static ssize_t class_attr_show(struct kobject *kobj, struct attribute *attr,
char *buf)
{
struct class_attribute *class_attr = to_class_attr(attr);
struct subsys_private *cp = to_subsys_private(kobj);
ssize_t ret = -EIO;
if (class_attr->show)
ret = class_attr->show(cp->class, class_attr, buf);
return ret;
}
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 subsys_private *cp = to_subsys_private(kobj);
ssize_t ret = -EIO;
if (class_attr->store)
ret = class_attr->store(cp->class, class_attr, buf, count);
return ret;
}
static void class_release(struct kobject *kobj)
{
struct subsys_private *cp = to_subsys_private(kobj);
const struct class *class = cp->class;
pr_debug("class '%s': release.\n", class->name);
if (class->class_release)
class->class_release(class);
else
pr_debug("class '%s' does not have a release() function, "
"be careful\n", class->name);
lockdep_unregister_key(&cp->lock_key);
kfree(cp);
}
static const struct kobj_ns_type_operations *class_child_ns_type(const struct kobject *kobj)
{
const struct subsys_private *cp = to_subsys_private(kobj);
const struct class *class = cp->class;
return class->ns_type;
}
static const struct sysfs_ops class_sysfs_ops = {
.show = class_attr_show,
.store = class_attr_store,
};
static const struct kobj_type class_ktype = {
.sysfs_ops = &class_sysfs_ops,
.release = class_release,
.child_ns_type = class_child_ns_type,
};
int class_create_file_ns(const struct class *cls, const struct class_attribute *attr,
const void *ns)
{
struct subsys_private *sp = class_to_subsys(cls);
int error;
if (!sp)
return -EINVAL;
error = sysfs_create_file_ns(&sp->subsys.kobj, &attr->attr, ns);
subsys_put(sp);
return error;
}
EXPORT_SYMBOL_GPL(class_create_file_ns);
void class_remove_file_ns(const struct class *cls, const struct class_attribute *attr,
const void *ns)
{
struct subsys_private *sp = class_to_subsys(cls);
if (!sp)
return;
sysfs_remove_file_ns(&sp->subsys.kobj, &attr->attr, ns);
subsys_put(sp);
}
EXPORT_SYMBOL_GPL(class_remove_file_ns);
static struct device *klist_class_to_dev(struct klist_node *n)
{
struct device_private *p = to_device_private_class(n);
return p->device;
}
static void klist_class_dev_get(struct klist_node *n)
{
struct device *dev = klist_class_to_dev(n);
get_device(dev);
}
static void klist_class_dev_put(struct klist_node *n)
{
struct device *dev = klist_class_to_dev(n);
put_device(dev);
}
int class_register(const struct class *cls)
{
struct subsys_private *cp;
struct lock_class_key *key;
int error;
pr_debug("device class '%s': registering\n", cls->name);
cp = kzalloc(sizeof(*cp), GFP_KERNEL);
if (!cp)
return -ENOMEM;
klist_init(&cp->klist_devices, klist_class_dev_get, klist_class_dev_put);
INIT_LIST_HEAD(&cp->interfaces);
kset_init(&cp->glue_dirs);
key = &cp->lock_key;
lockdep_register_key(key);
__mutex_init(&cp->mutex, "subsys mutex", key);
error = kobject_set_name(&cp->subsys.kobj, "%s", cls->name);
if (error)
goto err_out;
cp->subsys.kobj.kset = class_kset;
cp->subsys.kobj.ktype = &class_ktype;
cp->class = cls;
error = kset_register(&cp->subsys);
if (error)
goto err_out;
error = sysfs_create_groups(&cp->subsys.kobj, cls->class_groups);
if (error) {
kobject_del(&cp->subsys.kobj);
kfree_const(cp->subsys.kobj.name);
goto err_out;
}
return 0;
err_out:
lockdep_unregister_key(key);
kfree(cp);
return error;
}
EXPORT_SYMBOL_GPL(class_register);
void class_unregister(const struct class *cls)
{
struct subsys_private *sp = class_to_subsys(cls);
if (!sp)
return;
pr_debug("device class '%s': unregistering\n", cls->name);
sysfs_remove_groups(&sp->subsys.kobj, cls->class_groups);
kset_unregister(&sp->subsys);
subsys_put(sp);
}
EXPORT_SYMBOL_GPL(class_unregister);
static void class_create_release(const struct class *cls)
{
pr_debug("%s called for %s\n", __func__, cls->name);
kfree(cls);
}
/**
* class_create - create a struct class structure
* @name: pointer to a string for the name of this class.
*
* 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(const char *name)
{
struct class *cls;
int retval;
cls = kzalloc(sizeof(*cls), GFP_KERNEL);
if (!cls) {
retval = -ENOMEM;
goto error;
}
cls->name = name;
cls->class_release = class_create_release;
retval = class_register(cls);
if (retval)
goto error;
return cls;
error:
kfree(cls);
return ERR_PTR(retval);
}
EXPORT_SYMBOL_GPL(class_create);
/**
* class_destroy - destroys a struct class structure
* @cls: pointer to the struct class that is to be destroyed
*
* Note, the pointer to be destroyed must have been created with a call
* to class_create().
*/
void class_destroy(const struct class *cls)
{
if (IS_ERR_OR_NULL(cls))
return;
class_unregister(cls);
}
EXPORT_SYMBOL_GPL(class_destroy);
/**
* 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, const struct class *class,
const struct device *start, const struct device_type *type)
{
struct subsys_private *sp = class_to_subsys(class);
struct klist_node *start_knode = NULL;
if (!sp)
return;
if (start)
start_knode = &start->p->knode_class;
klist_iter_init_node(&sp->klist_devices, &iter->ki, start_knode);
iter->type = type;
iter->sp = sp;
}
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 = klist_class_to_dev(knode);
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);
subsys_put(iter->sp);
}
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.
* @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. 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.
*
* @fn is allowed to do anything including calling back into class
* code. There's no locking restriction.
*/
int class_for_each_device(const struct class *class, const struct device *start,
void *data, int (*fn)(struct device *, void *))
{
struct subsys_private *sp = class_to_subsys(class);
struct class_dev_iter iter;
struct device *dev;
int error = 0;
if (!class)
return -EINVAL;
if (!sp) {
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);
if (error)
break;
}
class_dev_iter_exit(&iter);
subsys_put(sp);
return error;
}
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
*
* This is similar to the class_for_each_dev() function above, but it
* returns a reference to a device that is 'found' for later use, as
* determined by the @match callback.
*
* The callback should return 0 if the device doesn't match and non-zero
* if it does. If the callback returns non-zero, this function will
* return to the caller and not iterate over any more devices.
*
* Note, you will need to drop the reference with put_device() after use.
*
* @match is allowed to do anything including calling back into class
* code. There's no locking restriction.
*/
struct device *class_find_device(const struct class *class, const struct device *start,
const void *data,
int (*match)(struct device *, const void *))
{
struct subsys_private *sp = class_to_subsys(class);
struct class_dev_iter iter;
struct device *dev;
if (!class)
return NULL;
if (!sp) {
WARN(1, "%s called for class '%s' before it was initialized",
__func__, class->name);
return NULL;
}
class_dev_iter_init(&iter, class, start, NULL);
while ((dev = class_dev_iter_next(&iter))) {
if (match(dev, data)) {
get_device(dev);
break;
}
}
class_dev_iter_exit(&iter);
subsys_put(sp);
return dev;
}
EXPORT_SYMBOL_GPL(class_find_device);
int class_interface_register(struct class_interface *class_intf)
{
struct subsys_private *sp;
const struct class *parent;
struct class_dev_iter iter;
struct device *dev;
if (!class_intf || !class_intf->class)
return -ENODEV;
parent = class_intf->class;
sp = class_to_subsys(parent);
if (!sp)
return -EINVAL;
/*
* Reference in sp is now incremented and will be dropped when
* the interface is removed in the call to class_interface_unregister()
*/
mutex_lock(&sp->mutex);
list_add_tail(&class_intf->node, &sp->interfaces);
if (class_intf->add_dev) {
class_dev_iter_init(&iter, parent, NULL, NULL);
while ((dev = class_dev_iter_next(&iter)))
class_intf->add_dev(dev);
class_dev_iter_exit(&iter);
}
mutex_unlock(&sp->mutex);
return 0;
}
EXPORT_SYMBOL_GPL(class_interface_register);
void class_interface_unregister(struct class_interface *class_intf)
{
struct subsys_private *sp;
const struct class *parent = class_intf->class;
struct class_dev_iter iter;
struct device *dev;
if (!parent)
return;
sp = class_to_subsys(parent);
if (!sp)
return;
mutex_lock(&sp->mutex);
list_del_init(&class_intf->node);
if (class_intf->remove_dev) {
class_dev_iter_init(&iter, parent, NULL, NULL);
while ((dev = class_dev_iter_next(&iter)))
class_intf->remove_dev(dev);
class_dev_iter_exit(&iter);
}
mutex_unlock(&sp->mutex);
/*
* Decrement the reference count twice, once for the class_to_subsys()
* call in the start of this function, and the second one from the
* reference increment in class_interface_register()
*/
subsys_put(sp);
subsys_put(sp);
}
EXPORT_SYMBOL_GPL(class_interface_unregister);
ssize_t show_class_attr_string(const struct class *class,
const struct class_attribute *attr, char *buf)
{
struct class_attribute_string *cs;
cs = container_of(attr, struct class_attribute_string, attr);
return sysfs_emit(buf, "%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);
/**
* class_is_registered - determine if at this moment in time, a class is
* registered in the driver core or not.
* @class: the class to check
*
* Returns a boolean to state if the class is registered in the driver core
* or not. Note that the value could switch right after this call is made,
* so only use this in places where you "know" it is safe to do so (usually
* to determine if the specific class has been registered yet or not).
*
* Be careful in using this.
*/
bool class_is_registered(const struct class *class)
{
struct subsys_private *sp = class_to_subsys(class);
bool is_initialized = false;
if (sp) {
is_initialized = true;
subsys_put(sp);
}
return is_initialized;
}
EXPORT_SYMBOL_GPL(class_is_registered);
int __init classes_init(void)
{
class_kset = kset_create_and_add("class", NULL, NULL);
if (!class_kset)
return -ENOMEM;
return 0;
}