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 12 static char *make_driver_name(const 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 23 static 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 33 int module_add_driver(struct module *mod, const struct device_driver *drv) 34 { 35 char *driver_name; 36 struct module_kobject *mk = NULL; 37 int ret; 38 39 if (!drv) 40 return 0; 41 42 if (mod) 43 mk = &mod->mkobj; 44 else if (drv->mod_name) { 45 /* Lookup or create built-in module entry in /sys/modules */ 46 mk = lookup_or_create_module_kobject(drv->mod_name); 47 if (mk) { 48 /* remember our module structure */ 49 drv->p->mkobj = mk; 50 /* lookup_or_create_module_kobject took a reference */ 51 kobject_put(&mk->kobj); 52 } 53 } 54 55 if (!mk) 56 return 0; 57 58 ret = sysfs_create_link(&drv->p->kobj, &mk->kobj, "module"); 59 if (ret) 60 return ret; 61 62 driver_name = make_driver_name(drv); 63 if (!driver_name) { 64 ret = -ENOMEM; 65 goto out_remove_kobj; 66 } 67 68 module_create_drivers_dir(mk); 69 if (!mk->drivers_dir) { 70 ret = -EINVAL; 71 goto out_free_driver_name; 72 } 73 74 ret = sysfs_create_link(mk->drivers_dir, &drv->p->kobj, driver_name); 75 if (ret) 76 goto out_remove_drivers_dir; 77 78 kfree(driver_name); 79 80 return 0; 81 82 out_remove_drivers_dir: 83 sysfs_remove_link(mk->drivers_dir, driver_name); 84 85 out_free_driver_name: 86 kfree(driver_name); 87 88 out_remove_kobj: 89 sysfs_remove_link(&drv->p->kobj, "module"); 90 return ret; 91 } 92 93 void module_remove_driver(const struct device_driver *drv) 94 { 95 struct module_kobject *mk = NULL; 96 char *driver_name; 97 98 if (!drv) 99 return; 100 101 sysfs_remove_link(&drv->p->kobj, "module"); 102 103 if (drv->owner) 104 mk = &drv->owner->mkobj; 105 else if (drv->p->mkobj) 106 mk = drv->p->mkobj; 107 if (mk && mk->drivers_dir) { 108 driver_name = make_driver_name(drv); 109 if (driver_name) { 110 sysfs_remove_link(mk->drivers_dir, driver_name); 111 kfree(driver_name); 112 } 113 } 114 } 115