LXR linux/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        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
  35void 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
  74void 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