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class: move driver core specific parts to a private structure
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This moves the portions of struct class that are dynamic (kobject and
lock and lists) out of the main structure and into a dynamic, private,
structure.


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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@gregkh
gregkh committed Jul 22, 2008
1 parent 16be63f commit 7c71448
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Showing 4 changed files with 107 additions and 71 deletions.
27 changes: 27 additions & 0 deletions drivers/base/base.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,33 @@ struct driver_private {
};
#define to_driver(obj) container_of(obj, struct driver_private, kobj)


/**
* struct class_private - structure to hold the private to the driver core portions of the class structure.
*
* @subsys - the struct kset that defines this class. This is the main kobject
* @children - list of class_devices associated with this class
* @devices - list of devices associated with this class
* @interfaces - list of class_interfaces associated with this class
* @class_dirs -
* @sem - semaphore to protect the children, devices, and interfaces lists.
* @class - pointer back to the struct class that this structure is associated
* with.
*
* This structure is the one that is the actual kobject allowing struct
* class to be statically allocated safely. Nothing outside of the driver
* core should ever touch these fields.
*/
struct class_private {
struct kset subsys;
struct list_head devices;
struct list_head interfaces;
struct kset class_dirs;
struct semaphore sem;
struct class *class;
};
#define to_class(obj) container_of(obj, struct class_private, subsys.kobj)

/* initialisation functions */
extern int devices_init(void);
extern int buses_init(void);
Expand Down
87 changes: 48 additions & 39 deletions drivers/base/class.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -21,35 +21,35 @@
#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;
}

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);

Expand Down Expand Up @@ -78,7 +78,7 @@ 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->subsys.kobj, &attr->attr);
else
error = -EINVAL;
return error;
Expand All @@ -87,21 +87,20 @@ 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->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->subsys);
return cls;
}

static void class_put(struct class *cls)
{
if (cls)
kset_put(&cls->subsys);
kset_put(&cls->p->subsys);
}

static int add_class_attrs(struct class *cls)
Expand Down Expand Up @@ -136,17 +135,23 @@ static void remove_class_attrs(struct class *cls)

int class_register(struct class *cls)
{
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->devices);
INIT_LIST_HEAD(&cp->interfaces);
kset_init(&cp->class_dirs);
init_MUTEX(&cp->sem);
error = kobject_set_name(&cp->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)
Expand All @@ -155,25 +160,29 @@ 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)
cls->subsys.kobj.kset = class_kset;
cp->subsys.kobj.kset = class_kset;
#else
cls->subsys.kobj.kset = class_kset;
cp->subsys.kobj.kset = class_kset;
#endif
cls->subsys.kobj.ktype = &class_ktype;
cp->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->subsys);
if (error) {
kfree(cp);
return error;
}
error = add_class_attrs(class_get(cls));
class_put(cls);
return error;
}

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->subsys);
}

static void class_create_release(struct class *cls)
Expand Down Expand Up @@ -280,8 +289,8 @@ int class_for_each_device(struct class *class, struct device *start,

if (!class)
return -EINVAL;
down(&class->sem);
list_for_each_entry(dev, &class->devices, node) {
down(&class->p->sem);
list_for_each_entry(dev, &class->p->devices, node) {
if (start) {
if (start == dev)
start = NULL;
Expand All @@ -293,7 +302,7 @@ int class_for_each_device(struct class *class, struct device *start,
if (error)
break;
}
up(&class->sem);
up(&class->p->sem);

return error;
}
Expand Down Expand Up @@ -330,8 +339,8 @@ struct device *class_find_device(struct class *class, struct device *start,
if (!class)
return NULL;

down(&class->sem);
list_for_each_entry(dev, &class->devices, node) {
down(&class->p->sem);
list_for_each_entry(dev, &class->p->devices, node) {
if (start) {
if (start == dev)
start = NULL;
Expand All @@ -344,7 +353,7 @@ struct device *class_find_device(struct class *class, struct device *start,
} else
put_device(dev);
}
up(&class->sem);
up(&class->p->sem);

return found ? dev : NULL;
}
Expand All @@ -362,13 +371,13 @@ int class_interface_register(struct class_interface *class_intf)
if (!parent)
return -EINVAL;

down(&parent->sem);
list_add_tail(&class_intf->node, &parent->interfaces);
down(&parent->p->sem);
list_add_tail(&class_intf->node, &parent->p->interfaces);
if (class_intf->add_dev) {
list_for_each_entry(dev, &parent->devices, node)
list_for_each_entry(dev, &parent->p->devices, node)
class_intf->add_dev(dev, class_intf);
}
up(&parent->sem);
up(&parent->p->sem);

return 0;
}
Expand All @@ -381,13 +390,13 @@ void class_interface_unregister(struct class_interface *class_intf)
if (!parent)
return;

down(&parent->sem);
down(&parent->p->sem);
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->devices, node)
class_intf->remove_dev(dev, class_intf);
}
up(&parent->sem);
up(&parent->p->sem);

class_put(parent);
}
Expand Down
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