LXR linux/drivers/base/module.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * module.c - module sysfs fun for drivers
   4 */
   5#include <linux/device.h>
   6#include <linux/module.h>
   7#include <linux/errno.h>
   8#include <linux/slab.h>
   9#include <linux/string.h>
  10#include "base.h"
  11
  12static char *make_driver_name(struct device_driver *drv)
  13{
  14        char *driver_name;
  15
  16        driver_name = kasprintf(GFP_KERNEL, "%s:%s", drv->bus->name, drv->name);
  17        if (!driver_name)
  18                return NULL;
  19
  20        return driver_name;
  21}
  22
  23static void module_create_drivers_dir(struct module_kobject *mk)
  24{
  25        static DEFINE_MUTEX(drivers_dir_mutex);
  26
  27        mutex_lock(&drivers_dir_mutex);
  28        if (mk && !mk->drivers_dir)
  29                mk->drivers_dir = kobject_create_and_add("drivers", &mk->kobj);
  30        mutex_unlock(&drivers_dir_mutex);
  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