drivers/cpuidle/sysfs.c

   1 /*
   2  * sysfs.c - sysfs support
   3  *
   4  * (C) 2006-2007 Shaohua Li <shaohua.li@intel.com>
   5  *
   6  * This code is licenced under the GPL.
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/cpuidle.h>
  11 #include <linux/sysfs.h>
  12 #include <linux/slab.h>
  13 #include <linux/cpu.h>
  14 #include <linux/completion.h>
  15 #include <linux/capability.h>
  16 #include <linux/device.h>
  17 #include <linux/kobject.h>
  18
  19 #include "cpuidle.h"
  20
  21 static unsigned int sysfs_switch;
  22 static int __init cpuidle_sysfs_setup(char *unused)
  23 {
  24         sysfs_switch = 1;
  25         return 1;
  26 }
  27 __setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);
  28
  29 static ssize_t show_available_governors(struct device *dev,
  30                                         struct device_attribute *attr,
  31                                         char *buf)
  32 {
  33         ssize_t i = 0;
  34         struct cpuidle_governor *tmp;
  35
  36         mutex_lock(&cpuidle_lock);
  37         list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
  38                 if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) -
  39                                     CPUIDLE_NAME_LEN - 2))
  40                         goto out;
  41                 i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
  42         }
  43
  44 out:
  45         i+= sprintf(&buf[i], "\n");
  46         mutex_unlock(&cpuidle_lock);
  47         return i;
  48 }
  49
  50 static ssize_t show_current_driver(struct device *dev,
  51                                    struct device_attribute *attr,
  52                                    char *buf)
  53 {
  54         ssize_t ret;
  55         struct cpuidle_driver *drv;
  56
  57         spin_lock(&cpuidle_driver_lock);
  58         drv = cpuidle_get_driver();
  59         if (drv)
  60                 ret = sprintf(buf, "%s\n", drv->name);
  61         else
  62                 ret = sprintf(buf, "none\n");
  63         spin_unlock(&cpuidle_driver_lock);
  64
  65         return ret;
  66 }
  67
  68 static ssize_t show_current_governor(struct device *dev,
  69                                      struct device_attribute *attr,
  70                                      char *buf)
  71 {
  72         ssize_t ret;
  73
  74         mutex_lock(&cpuidle_lock);
  75         if (cpuidle_curr_governor)
  76                 ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
  77         else
  78                 ret = sprintf(buf, "none\n");
  79         mutex_unlock(&cpuidle_lock);
  80
  81         return ret;
  82 }
  83
  84 static ssize_t store_current_governor(struct device *dev,
  85                                       struct device_attribute *attr,
  86                                       const char *buf, size_t count)
  87 {
  88         char gov_name[CPUIDLE_NAME_LEN];
  89         int ret = -EINVAL;
  90         size_t len = count;
  91         struct cpuidle_governor *gov;
  92
  93         if (!len || len >= sizeof(gov_name))
  94                 return -EINVAL;
  95
  96         memcpy(gov_name, buf, len);
  97         gov_name[len] = '\0';
  98         if (gov_name[len - 1] == '\n')
  99                 gov_name[--len] = '\0';
 100
 101         mutex_lock(&cpuidle_lock);
 102
 103         list_for_each_entry(gov, &cpuidle_governors, governor_list) {
 104                 if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
 105                         ret = cpuidle_switch_governor(gov);
 106                         break;
 107                 }
 108         }
 109
 110         mutex_unlock(&cpuidle_lock);
 111
 112         if (ret)
 113                 return ret;
 114         else
 115                 return count;
 116 }
 117
 118 static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
 119 static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
 120
 121 static struct attribute *cpuidle_default_attrs[] = {
 122         &dev_attr_current_driver.attr,
 123         &dev_attr_current_governor_ro.attr,
 124         NULL
 125 };
 126
 127 static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
 128 static DEVICE_ATTR(current_governor, 0644, show_current_governor,
 129                    store_current_governor);
 130
 131 static struct attribute *cpuidle_switch_attrs[] = {
 132         &dev_attr_available_governors.attr,
 133         &dev_attr_current_driver.attr,
 134         &dev_attr_current_governor.attr,
 135         NULL
 136 };
 137
 138 static struct attribute_group cpuidle_attr_group = {
 139         .attrs = cpuidle_default_attrs,
 140         .name = "cpuidle",
 141 };
 142
 143 /**
 144  * cpuidle_add_interface - add CPU global sysfs attributes
 145  */
 146 int cpuidle_add_interface(struct device *dev)
 147 {
 148         if (sysfs_switch)
 149                 cpuidle_attr_group.attrs = cpuidle_switch_attrs;
 150
 151         return sysfs_create_group(&dev->kobj, &cpuidle_attr_group);
 152 }
 153
 154 /**
 155  * cpuidle_remove_interface - remove CPU global sysfs attributes
 156  */
 157 void cpuidle_remove_interface(struct device *dev)
 158 {
 159         sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
 160 }
 161
 162 struct cpuidle_attr {
 163         struct attribute attr;
 164         ssize_t (*show)(struct cpuidle_device *, char *);
 165         ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
 166 };
 167
 168 #define define_one_ro(_name, show) \
 169         static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 170 #define define_one_rw(_name, show, store) \
 171         static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
 172
 173 #define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
 174
 175 struct cpuidle_device_kobj {
 176         struct cpuidle_device *dev;
 177         struct completion kobj_unregister;
 178         struct kobject kobj;
 179 };
 180
 181 static inline struct cpuidle_device *to_cpuidle_device(struct kobject *kobj)
 182 {
 183         struct cpuidle_device_kobj *kdev =
 184                 container_of(kobj, struct cpuidle_device_kobj, kobj);
 185
 186         return kdev->dev;
 187 }
 188
 189 static ssize_t cpuidle_show(struct kobject *kobj, struct attribute *attr,
 190                             char *buf)
 191 {
 192         int ret = -EIO;
 193         struct cpuidle_device *dev = to_cpuidle_device(kobj);
 194         struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
 195
 196         if (cattr->show) {
 197                 mutex_lock(&cpuidle_lock);
 198                 ret = cattr->show(dev, buf);
 199                 mutex_unlock(&cpuidle_lock);
 200         }
 201         return ret;
 202 }
 203
 204 static ssize_t cpuidle_store(struct kobject *kobj, struct attribute *attr,
 205                              const char *buf, size_t count)
 206 {
 207         int ret = -EIO;
 208         struct cpuidle_device *dev = to_cpuidle_device(kobj);
 209         struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
 210
 211         if (cattr->store) {
 212                 mutex_lock(&cpuidle_lock);
 213                 ret = cattr->store(dev, buf, count);
 214                 mutex_unlock(&cpuidle_lock);
 215         }
 216         return ret;
 217 }
 218
 219 static const struct sysfs_ops cpuidle_sysfs_ops = {
 220         .show = cpuidle_show,
 221         .store = cpuidle_store,
 222 };
 223
 224 static void cpuidle_sysfs_release(struct kobject *kobj)
 225 {
 226         struct cpuidle_device_kobj *kdev =
 227                 container_of(kobj, struct cpuidle_device_kobj, kobj);
 228
 229         complete(&kdev->kobj_unregister);
 230 }
 231
 232 static struct kobj_type ktype_cpuidle = {
 233         .sysfs_ops = &cpuidle_sysfs_ops,
 234         .release = cpuidle_sysfs_release,
 235 };
 236
 237 struct cpuidle_state_attr {
 238         struct attribute attr;
 239         ssize_t (*show)(struct cpuidle_state *, \
 240                                         struct cpuidle_state_usage *, char *);
 241         ssize_t (*store)(struct cpuidle_state *, \
 242                         struct cpuidle_state_usage *, const char *, size_t);
 243 };
 244
 245 #define define_one_state_ro(_name, show) \
 246 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 247
 248 #define define_one_state_rw(_name, show, store) \
 249 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
 250
 251 #define define_show_state_function(_name) \
 252 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 253                          struct cpuidle_state_usage *state_usage, char *buf) \
 254 { \
 255         return sprintf(buf, "%u\n", state->_name);\
 256 }
 257
 258 #define define_store_state_ull_function(_name) \
 259 static ssize_t store_state_##_name(struct cpuidle_state *state, \
 260                                    struct cpuidle_state_usage *state_usage, \
 261                                    const char *buf, size_t size)        \
 262 { \
 263         unsigned long long value; \
 264         int err; \
 265         if (!capable(CAP_SYS_ADMIN)) \
 266                 return -EPERM; \
 267         err = kstrtoull(buf, 0, &value); \
 268         if (err) \
 269                 return err; \
 270         if (value) \
 271                 state_usage->_name = 1; \
 272         else \
 273                 state_usage->_name = 0; \
 274         return size; \
 275 }
 276
 277 #define define_show_state_ull_function(_name) \
 278 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 279                                   struct cpuidle_state_usage *state_usage, \
 280                                   char *buf)                            \
 281 { \
 282         return sprintf(buf, "%llu\n", state_usage->_name);\
 283 }
 284
 285 #define define_show_state_str_function(_name) \
 286 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 287                                   struct cpuidle_state_usage *state_usage, \
 288                                   char *buf)                            \
 289 { \
 290         if (state->_name[0] == '\0')\
 291                 return sprintf(buf, "<null>\n");\
 292         return sprintf(buf, "%s\n", state->_name);\
 293 }
 294
 295 define_show_state_function(exit_latency)
 296 define_show_state_function(target_residency)
 297 define_show_state_function(power_usage)
 298 define_show_state_ull_function(usage)
 299 define_show_state_ull_function(time)
 300 define_show_state_str_function(name)
 301 define_show_state_str_function(desc)
 302 define_show_state_ull_function(disable)
 303 define_store_state_ull_function(disable)
 304
 305 define_one_state_ro(name, show_state_name);
 306 define_one_state_ro(desc, show_state_desc);
 307 define_one_state_ro(latency, show_state_exit_latency);
 308 define_one_state_ro(residency, show_state_target_residency);
 309 define_one_state_ro(power, show_state_power_usage);
 310 define_one_state_ro(usage, show_state_usage);
 311 define_one_state_ro(time, show_state_time);
 312 define_one_state_rw(disable, show_state_disable, store_state_disable);
 313
 314 static struct attribute *cpuidle_state_default_attrs[] = {
 315         &attr_name.attr,
 316         &attr_desc.attr,
 317         &attr_latency.attr,
 318         &attr_residency.attr,
 319         &attr_power.attr,
 320         &attr_usage.attr,
 321         &attr_time.attr,
 322         &attr_disable.attr,
 323         NULL
 324 };
 325
 326 struct cpuidle_state_kobj {
 327         struct cpuidle_state *state;
 328         struct cpuidle_state_usage *state_usage;
 329         struct completion kobj_unregister;
 330         struct kobject kobj;
 331 };
 332
 333 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
 334 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
 335 #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
 336 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
 337
 338 static ssize_t cpuidle_state_show(struct kobject *kobj, struct attribute *attr,
 339                                   char * buf)
 340 {
 341         int ret = -EIO;
 342         struct cpuidle_state *state = kobj_to_state(kobj);
 343         struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
 344         struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
 345
 346         if (cattr->show)
 347                 ret = cattr->show(state, state_usage, buf);
 348
 349         return ret;
 350 }
 351
 352 static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr,
 353                                    const char *buf, size_t size)
 354 {
 355         int ret = -EIO;
 356         struct cpuidle_state *state = kobj_to_state(kobj);
 357         struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
 358         struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
 359
 360         if (cattr->store)
 361                 ret = cattr->store(state, state_usage, buf, size);
 362
 363         return ret;
 364 }
 365
 366 static const struct sysfs_ops cpuidle_state_sysfs_ops = {
 367         .show = cpuidle_state_show,
 368         .store = cpuidle_state_store,
 369 };
 370
 371 static void cpuidle_state_sysfs_release(struct kobject *kobj)
 372 {
 373         struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
 374
 375         complete(&state_obj->kobj_unregister);
 376 }
 377
 378 static struct kobj_type ktype_state_cpuidle = {
 379         .sysfs_ops = &cpuidle_state_sysfs_ops,
 380         .default_attrs = cpuidle_state_default_attrs,
 381         .release = cpuidle_state_sysfs_release,
 382 };
 383
 384 static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
 385 {
 386         kobject_put(&device->kobjs[i]->kobj);
 387         wait_for_completion(&device->kobjs[i]->kobj_unregister);
 388         kfree(device->kobjs[i]);
 389         device->kobjs[i] = NULL;
 390 }
 391
 392 /**
 393  * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes
 394  * @device: the target device
 395  */
 396 static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
 397 {
 398         int i, ret = -ENOMEM;
 399         struct cpuidle_state_kobj *kobj;
 400         struct cpuidle_device_kobj *kdev = device->kobj_dev;
 401         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
 402
 403         /* state statistics */
 404         for (i = 0; i < drv->state_count; i++) {
 405                 kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
 406                 if (!kobj) {
 407                         ret = -ENOMEM;
 408                         goto error_state;
 409                 }
 410                 kobj->state = &drv->states[i];
 411                 kobj->state_usage = &device->states_usage[i];
 412                 init_completion(&kobj->kobj_unregister);
 413
 414                 ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
 415                                            &kdev->kobj, "state%d", i);
 416                 if (ret) {
 417                         kfree(kobj);
 418                         goto error_state;
 419                 }
 420                 kobject_uevent(&kobj->kobj, KOBJ_ADD);
 421                 device->kobjs[i] = kobj;
 422         }
 423
 424         return 0;
 425
 426 error_state:
 427         for (i = i - 1; i >= 0; i--)
 428                 cpuidle_free_state_kobj(device, i);
 429         return ret;
 430 }
 431
 432 /**
 433  * cpuidle_remove_driver_sysfs - removes the cpuidle states sysfs attributes
 434  * @device: the target device
 435  */
 436 static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
 437 {
 438         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
 439         int i;
 440
 441         for (i = 0; i < drv->state_count; i++)
 442                 cpuidle_free_state_kobj(device, i);
 443 }
 444
 445 #ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
 446 #define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
 447 #define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
 448
 449 #define define_one_driver_ro(_name, show)                       \
 450         static struct cpuidle_driver_attr attr_driver_##_name = \
 451                 __ATTR(_name, 0444, show, NULL)
 452
 453 struct cpuidle_driver_kobj {
 454         struct cpuidle_driver *drv;
 455         struct completion kobj_unregister;
 456         struct kobject kobj;
 457 };
 458
 459 struct cpuidle_driver_attr {
 460         struct attribute attr;
 461         ssize_t (*show)(struct cpuidle_driver *, char *);
 462         ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
 463 };
 464
 465 static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
 466 {
 467         ssize_t ret;
 468
 469         spin_lock(&cpuidle_driver_lock);
 470         ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
 471         spin_unlock(&cpuidle_driver_lock);
 472
 473         return ret;
 474 }
 475
 476 static void cpuidle_driver_sysfs_release(struct kobject *kobj)
 477 {
 478         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 479         complete(&driver_kobj->kobj_unregister);
 480 }
 481
 482 static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
 483                                    char *buf)
 484 {
 485         int ret = -EIO;
 486         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 487         struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
 488
 489         if (dattr->show)
 490                 ret = dattr->show(driver_kobj->drv, buf);
 491
 492         return ret;
 493 }
 494
 495 static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
 496                                     const char *buf, size_t size)
 497 {
 498         int ret = -EIO;
 499         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 500         struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
 501
 502         if (dattr->store)
 503                 ret = dattr->store(driver_kobj->drv, buf, size);
 504
 505         return ret;
 506 }
 507
 508 define_one_driver_ro(name, show_driver_name);
 509
 510 static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
 511         .show = cpuidle_driver_show,
 512         .store = cpuidle_driver_store,
 513 };
 514
 515 static struct attribute *cpuidle_driver_default_attrs[] = {
 516         &attr_driver_name.attr,
 517         NULL
 518 };
 519
 520 static struct kobj_type ktype_driver_cpuidle = {
 521         .sysfs_ops = &cpuidle_driver_sysfs_ops,
 522         .default_attrs = cpuidle_driver_default_attrs,
 523         .release = cpuidle_driver_sysfs_release,
 524 };
 525
 526 /**
 527  * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
 528  * @device: the target device
 529  */
 530 static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 531 {
 532         struct cpuidle_driver_kobj *kdrv;
 533         struct cpuidle_device_kobj *kdev = dev->kobj_dev;
 534         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
 535         int ret;
 536
 537         kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
 538         if (!kdrv)
 539                 return -ENOMEM;
 540
 541         kdrv->drv = drv;
 542         init_completion(&kdrv->kobj_unregister);
 543
 544         ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
 545                                    &kdev->kobj, "driver");
 546         if (ret) {
 547                 kfree(kdrv);
 548                 return ret;
 549         }
 550
 551         kobject_uevent(&kdrv->kobj, KOBJ_ADD);
 552         dev->kobj_driver = kdrv;
 553
 554         return ret;
 555 }
 556
 557 /**
 558  * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
 559  * @device: the target device
 560  */
 561 static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
 562 {
 563         struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
 564         kobject_put(&kdrv->kobj);
 565         wait_for_completion(&kdrv->kobj_unregister);
 566         kfree(kdrv);
 567 }
 568 #else
 569 static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 570 {
 571         return 0;
 572 }
 573
 574 static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
 575 {
 576         ;
 577 }
 578 #endif
 579
 580 /**
 581  * cpuidle_add_device_sysfs - adds device specific sysfs attributes
 582  * @device: the target device
 583  */
 584 int cpuidle_add_device_sysfs(struct cpuidle_device *device)
 585 {
 586         int ret;
 587
 588         ret = cpuidle_add_state_sysfs(device);
 589         if (ret)
 590                 return ret;
 591
 592         ret = cpuidle_add_driver_sysfs(device);
 593         if (ret)
 594                 cpuidle_remove_state_sysfs(device);
 595         return ret;
 596 }
 597
 598 /**
 599  * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
 600  * @device : the target device
 601  */
 602 void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
 603 {
 604         cpuidle_remove_driver_sysfs(device);
 605         cpuidle_remove_state_sysfs(device);
 606 }
 607
 608 /**
 609  * cpuidle_add_sysfs - creates a sysfs instance for the target device
 610  * @dev: the target device
 611  */
 612 int cpuidle_add_sysfs(struct cpuidle_device *dev)
 613 {
 614         struct cpuidle_device_kobj *kdev;
 615         struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
 616         int error;
 617
 618         /*
 619          * Return if cpu_device is not setup for this CPU.
 620          *
 621          * This could happen if the arch did not set up cpu_device
 622          * since this CPU is not in cpu_present mask and the
 623          * driver did not send a correct CPU mask during registration.
 624          * Without this check we would end up passing bogus
 625          * value for &cpu_dev->kobj in kobject_init_and_add()
 626          */
 627         if (!cpu_dev)
 628                 return -ENODEV;
 629
 630         kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
 631         if (!kdev)
 632                 return -ENOMEM;
 633         kdev->dev = dev;
 634         dev->kobj_dev = kdev;
 635
 636         init_completion(&kdev->kobj_unregister);
 637
 638         error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
 639                                    "cpuidle");
 640         if (error) {
 641                 kfree(kdev);
 642                 return error;
 643         }
 644
 645         kobject_uevent(&kdev->kobj, KOBJ_ADD);
 646
 647         return 0;
 648 }
 649
 650 /**
 651  * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
 652  * @dev: the target device
 653  */
 654 void cpuidle_remove_sysfs(struct cpuidle_device *dev)
 655 {
 656         struct cpuidle_device_kobj *kdev = dev->kobj_dev;
 657
 658         kobject_put(&kdev->kobj);
 659         wait_for_completion(&kdev->kobj_unregister);
 660         kfree(kdev);
 661 }