Root/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
14static 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
25static 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
33void 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
72void 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}
94

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