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