module.c

Go to the documentation of this file.

/*
 * 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)
{
    if (!mk || mk->drivers_dir)
        return;

    mk->drivers_dir = kobject_create_and_add("drivers", &mk->kobj);
}

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);
        }
    }
}