1 /*
2 * module.c - module sysfs fun for drivers
3 *
4 * This file is released under the GPLv2
5 *
6 */
7 #include <linux/device.h>
8 #include <linux/module.h>
9 #include <linux/errno.h>
10 #include <linux/slab.h>
11 #include <linux/string.h>
12 #include "base.h"
13
make_driver_name(struct device_driver * drv)14 static char *make_driver_name(struct device_driver *drv)
15 {
16 char *driver_name;
17
18 driver_name = kasprintf(GFP_KERNEL, "%s:%s", drv->bus->name, drv->name);
19 if (!driver_name)
20 return NULL;
21
22 return driver_name;
23 }
24
module_create_drivers_dir(struct module_kobject * mk)25 static void module_create_drivers_dir(struct module_kobject *mk)
26 {
27 static DEFINE_MUTEX(drivers_dir_mutex);
28
29 mutex_lock(&drivers_dir_mutex);
30 if (mk && !mk->drivers_dir)
31 mk->drivers_dir = kobject_create_and_add("drivers", &mk->kobj);
32 mutex_unlock(&drivers_dir_mutex);
33 }
34
module_add_driver(struct module * mod,struct device_driver * drv)35 void module_add_driver(struct module *mod, struct device_driver *drv)
36 {
37 char *driver_name;
38 int no_warn;
39 struct module_kobject *mk = NULL;
40
41 if (!drv)
42 return;
43
44 if (mod)
45 mk = &mod->mkobj;
46 else if (drv->mod_name) {
47 struct kobject *mkobj;
48
49 /* Lookup built-in module entry in /sys/modules */
50 mkobj = kset_find_obj(module_kset, drv->mod_name);
51 if (mkobj) {
52 mk = container_of(mkobj, struct module_kobject, kobj);
53 /* remember our module structure */
54 drv->p->mkobj = mk;
55 /* kset_find_obj took a reference */
56 kobject_put(mkobj);
57 }
58 }
59
60 if (!mk)
61 return;
62
63 /* Don't check return codes; these calls are idempotent */
64 no_warn = sysfs_create_link(&drv->p->kobj, &mk->kobj, "module");
65 driver_name = make_driver_name(drv);
66 if (driver_name) {
67 module_create_drivers_dir(mk);
68 no_warn = sysfs_create_link(mk->drivers_dir, &drv->p->kobj,
69 driver_name);
70 kfree(driver_name);
71 }
72 }
73
module_remove_driver(struct device_driver * drv)74 void module_remove_driver(struct device_driver *drv)
75 {
76 struct module_kobject *mk = NULL;
77 char *driver_name;
78
79 if (!drv)
80 return;
81
82 sysfs_remove_link(&drv->p->kobj, "module");
83
84 if (drv->owner)
85 mk = &drv->owner->mkobj;
86 else if (drv->p->mkobj)
87 mk = drv->p->mkobj;
88 if (mk && mk->drivers_dir) {
89 driver_name = make_driver_name(drv);
90 if (driver_name) {
91 sysfs_remove_link(mk->drivers_dir, driver_name);
92 kfree(driver_name);
93 }
94 }
95 }
96