/*
   * module.c - module sysfs fun for drivers
   *
   * This file is released under the GPLv2
   *
   */
  #include <linux/device.h>
  #include <linux/module.h>
  #include <linux/errno.h>

  #include <linux/slab.h>

  #include <linux/string.h>
  #include "base.h"
  
  static char *make_driver_name(struct device_driver *drv)
  {
  	char *driver_name;

  	driver_name = kasprintf(GFP_KERNEL, "%s:%s", drv->bus->name, drv->name);

  	if (!driver_name)
  		return NULL;

  	return driver_name;
  }
  
  static void module_create_drivers_dir(struct module_kobject *mk)
  {

  	static DEFINE_MUTEX(drivers_dir_mutex);

  	mutex_lock(&drivers_dir_mutex);
  	if (mk && !mk->drivers_dir)
  		mk->drivers_dir = kobject_create_and_add("drivers", &mk->kobj);
  	mutex_unlock(&drivers_dir_mutex);

  }
  
  void module_add_driver(struct module *mod, struct device_driver *drv)
  {
  	char *driver_name;
  	int no_warn;
  	struct module_kobject *mk = NULL;
  
  	if (!drv)
  		return;
  
  	if (mod)
  		mk = &mod->mkobj;
  	else if (drv->mod_name) {
  		struct kobject *mkobj;
  
  		/* Lookup built-in module entry in /sys/modules */
  		mkobj = kset_find_obj(module_kset, drv->mod_name);
  		if (mkobj) {
  			mk = container_of(mkobj, struct module_kobject, kobj);
  			/* remember our module structure */

  			drv->p->mkobj = mk;

  			/* kset_find_obj took a reference */
  			kobject_put(mkobj);
  		}
  	}
  
  	if (!mk)
  		return;
  
  	/* Don't check return codes; these calls are idempotent */

  	no_warn = sysfs_create_link(&drv->p->kobj, &mk->kobj, "module");

  	driver_name = make_driver_name(drv);
  	if (driver_name) {
  		module_create_drivers_dir(mk);

  		no_warn = sysfs_create_link(mk->drivers_dir, &drv->p->kobj,

  					    driver_name);
  		kfree(driver_name);
  	}
  }
  
  void module_remove_driver(struct device_driver *drv)
  {
  	struct module_kobject *mk = NULL;
  	char *driver_name;
  
  	if (!drv)
  		return;

  	sysfs_remove_link(&drv->p->kobj, "module");

  
  	if (drv->owner)
  		mk = &drv->owner->mkobj;

  	else if (drv->p->mkobj)
  		mk = drv->p->mkobj;

  	if (mk && mk->drivers_dir) {
  		driver_name = make_driver_name(drv);
  		if (driver_name) {
  			sysfs_remove_link(mk->drivers_dir, driver_name);
  			kfree(driver_name);
  		}
  	}
  }