PM / Sleep: Add wakeup_source_activate and wakeup_source_deactivate tracepoints
[linux-2.6.git] / drivers / base / module.c
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
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
25 static void module_create_drivers_dir(struct module_kobject *mk)
26 {
27         if (!mk || mk->drivers_dir)
28                 return;
29
30         mk->drivers_dir = kobject_create_and_add("drivers", &mk->kobj);
31 }
32
33 void module_add_driver(struct module *mod, struct device_driver *drv)
34 {
35         char *driver_name;
36         int no_warn;
37         struct module_kobject *mk = NULL;
38
39         if (!drv)
40                 return;
41
42         if (mod)
43                 mk = &mod->mkobj;
44         else if (drv->mod_name) {
45                 struct kobject *mkobj;
46
47                 /* Lookup built-in module entry in /sys/modules */
48                 mkobj = kset_find_obj(module_kset, drv->mod_name);
49                 if (mkobj) {
50                         mk = container_of(mkobj, struct module_kobject, kobj);
51                         /* remember our module structure */
52                         drv->p->mkobj = mk;
53                         /* kset_find_obj took a reference */
54                         kobject_put(mkobj);
55                 }
56         }
57
58         if (!mk)
59                 return;
60
61         /* Don't check return codes; these calls are idempotent */
62         no_warn = sysfs_create_link(&drv->p->kobj, &mk->kobj, "module");
63         driver_name = make_driver_name(drv);
64         if (driver_name) {
65                 module_create_drivers_dir(mk);
66                 no_warn = sysfs_create_link(mk->drivers_dir, &drv->p->kobj,
67                                             driver_name);
68                 kfree(driver_name);
69         }
70 }
71
72 void module_remove_driver(struct device_driver *drv)
73 {
74         struct module_kobject *mk = NULL;
75         char *driver_name;
76
77         if (!drv)
78                 return;
79
80         sysfs_remove_link(&drv->p->kobj, "module");
81
82         if (drv->owner)
83                 mk = &drv->owner->mkobj;
84         else if (drv->p->mkobj)
85                 mk = drv->p->mkobj;
86         if (mk && mk->drivers_dir) {
87                 driver_name = make_driver_name(drv);
88                 if (driver_name) {
89                         sysfs_remove_link(mk->drivers_dir, driver_name);
90                         kfree(driver_name);
91                 }
92         }
93 }