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 ssize_t show_available_governors(struct device *dev,
  22                                         struct device_attribute *attr,
  23                                         char *buf)
  24 {
  25         ssize_t i = 0;
  26         struct cpuidle_governor *tmp;
  27
  28         mutex_lock(&cpuidle_lock);
  29         list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
  30                 if (i >= (ssize_t) (PAGE_SIZE - (CPUIDLE_NAME_LEN + 2)))
  31                         goto out;
  32
  33                 i += scnprintf(&buf[i], CPUIDLE_NAME_LEN + 1, "%s ", tmp->name);
  34         }
  35
  36 out:
  37         i+= sprintf(&buf[i], "\n");
  38         mutex_unlock(&cpuidle_lock);
  39         return i;
  40 }
  41
  42 static ssize_t show_current_driver(struct device *dev,
  43                                    struct device_attribute *attr,
  44                                    char *buf)
  45 {
  46         ssize_t ret;
  47         struct cpuidle_driver *drv;
  48
  49         spin_lock(&cpuidle_driver_lock);
  50         drv = cpuidle_get_driver();
  51         if (drv)
  52                 ret = sprintf(buf, "%s\n", drv->name);
  53         else
  54                 ret = sprintf(buf, "none\n");
  55         spin_unlock(&cpuidle_driver_lock);
  56
  57         return ret;
  58 }
  59
  60 static ssize_t show_current_governor(struct device *dev,
  61                                      struct device_attribute *attr,
  62                                      char *buf)
  63 {
  64         ssize_t ret;
  65
  66         mutex_lock(&cpuidle_lock);
  67         if (cpuidle_curr_governor)
  68                 ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
  69         else
  70                 ret = sprintf(buf, "none\n");
  71         mutex_unlock(&cpuidle_lock);
  72
  73         return ret;
  74 }
  75
  76 static ssize_t store_current_governor(struct device *dev,
  77                                       struct device_attribute *attr,
  78                                       const char *buf, size_t count)
  79 {
  80         char gov_name[CPUIDLE_NAME_LEN + 1];
  81         int ret;
  82         struct cpuidle_governor *gov;
  83
  84         ret = sscanf(buf, "%" __stringify(CPUIDLE_NAME_LEN) "s", gov_name);
  85         if (ret != 1)
  86                 return -EINVAL;
  87
  88         mutex_lock(&cpuidle_lock);
  89         ret = -EINVAL;
  90         list_for_each_entry(gov, &cpuidle_governors, governor_list) {
  91                 if (!strncmp(gov->name, gov_name, CPUIDLE_NAME_LEN)) {
  92                         ret = cpuidle_switch_governor(gov);
  93                         break;
  94                 }
  95         }
  96         mutex_unlock(&cpuidle_lock);
  97
  98         return ret ? ret : count;
  99 }
 100
 101 static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
 102 static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
 103 static DEVICE_ATTR(current_governor, 0644, show_current_governor,
 104                                    store_current_governor);
 105 static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
 106
 107 static struct attribute *cpuidle_attrs[] = {
 108         &dev_attr_available_governors.attr,
 109         &dev_attr_current_driver.attr,
 110         &dev_attr_current_governor.attr,
 111         &dev_attr_current_governor_ro.attr,
 112         NULL
 113 };
 114
 115 static struct attribute_group cpuidle_attr_group = {
 116         .attrs = cpuidle_attrs,
 117         .name = "cpuidle",
 118 };
 119
 120 /**
 121  * cpuidle_add_interface - add CPU global sysfs attributes
 122  */
 123 int cpuidle_add_interface(void)
 124 {
 125         struct device *dev_root = bus_get_dev_root(&cpu_subsys);
 126         int retval;
 127
 128         if (!dev_root)
 129                 return -EINVAL;
 130
 131         retval = sysfs_create_group(&dev_root->kobj, &cpuidle_attr_group);
 132         put_device(dev_root);
 133         return retval;
 134 }
 135
 136 /**
 137  * cpuidle_remove_interface - remove CPU global sysfs attributes
 138  * @dev: the target device
 139  */
 140 void cpuidle_remove_interface(struct device *dev)
 141 {
 142         sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
 143 }
 144
 145 struct cpuidle_attr {
 146         struct attribute attr;
 147         ssize_t (*show)(struct cpuidle_device *, char *);
 148         ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
 149 };
 150
 151 #define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
 152
 153 struct cpuidle_device_kobj {
 154         struct cpuidle_device *dev;
 155         struct completion kobj_unregister;
 156         struct kobject kobj;
 157 };
 158
 159 static inline struct cpuidle_device *to_cpuidle_device(struct kobject *kobj)
 160 {
 161         struct cpuidle_device_kobj *kdev =
 162                 container_of(kobj, struct cpuidle_device_kobj, kobj);
 163
 164         return kdev->dev;
 165 }
 166
 167 static ssize_t cpuidle_show(struct kobject *kobj, struct attribute *attr,
 168                             char *buf)
 169 {
 170         int ret = -EIO;
 171         struct cpuidle_device *dev = to_cpuidle_device(kobj);
 172         struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
 173
 174         if (cattr->show) {
 175                 mutex_lock(&cpuidle_lock);
 176                 ret = cattr->show(dev, buf);
 177                 mutex_unlock(&cpuidle_lock);
 178         }
 179         return ret;
 180 }
 181
 182 static ssize_t cpuidle_store(struct kobject *kobj, struct attribute *attr,
 183                              const char *buf, size_t count)
 184 {
 185         int ret = -EIO;
 186         struct cpuidle_device *dev = to_cpuidle_device(kobj);
 187         struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
 188
 189         if (cattr->store) {
 190                 mutex_lock(&cpuidle_lock);
 191                 ret = cattr->store(dev, buf, count);
 192                 mutex_unlock(&cpuidle_lock);
 193         }
 194         return ret;
 195 }
 196
 197 static const struct sysfs_ops cpuidle_sysfs_ops = {
 198         .show = cpuidle_show,
 199         .store = cpuidle_store,
 200 };
 201
 202 static void cpuidle_sysfs_release(struct kobject *kobj)
 203 {
 204         struct cpuidle_device_kobj *kdev =
 205                 container_of(kobj, struct cpuidle_device_kobj, kobj);
 206
 207         complete(&kdev->kobj_unregister);
 208 }
 209
 210 static const struct kobj_type ktype_cpuidle = {
 211         .sysfs_ops = &cpuidle_sysfs_ops,
 212         .release = cpuidle_sysfs_release,
 213 };
 214
 215 struct cpuidle_state_attr {
 216         struct attribute attr;
 217         ssize_t (*show)(struct cpuidle_state *, \
 218                                         struct cpuidle_state_usage *, char *);
 219         ssize_t (*store)(struct cpuidle_state *, \
 220                         struct cpuidle_state_usage *, const char *, size_t);
 221 };
 222
 223 #define define_one_state_ro(_name, show) \
 224 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 225
 226 #define define_one_state_rw(_name, show, store) \
 227 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
 228
 229 #define define_show_state_function(_name) \
 230 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 231                          struct cpuidle_state_usage *state_usage, char *buf) \
 232 { \
 233         return sprintf(buf, "%u\n", state->_name);\
 234 }
 235
 236 #define define_show_state_ull_function(_name) \
 237 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 238                                   struct cpuidle_state_usage *state_usage, \
 239                                   char *buf)                            \
 240 { \
 241         return sprintf(buf, "%llu\n", state_usage->_name);\
 242 }
 243
 244 #define define_show_state_str_function(_name) \
 245 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 246                                   struct cpuidle_state_usage *state_usage, \
 247                                   char *buf)                            \
 248 { \
 249         if (state->_name[0] == '\0')\
 250                 return sprintf(buf, "<null>\n");\
 251         return sprintf(buf, "%s\n", state->_name);\
 252 }
 253
 254 #define define_show_state_time_function(_name) \
 255 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 256                                   struct cpuidle_state_usage *state_usage, \
 257                                   char *buf) \
 258 { \
 259         return sprintf(buf, "%llu\n", ktime_to_us(state->_name##_ns)); \
 260 }
 261
 262 define_show_state_time_function(exit_latency)
 263 define_show_state_time_function(target_residency)
 264 define_show_state_function(power_usage)
 265 define_show_state_ull_function(usage)
 266 define_show_state_ull_function(rejected)
 267 define_show_state_str_function(name)
 268 define_show_state_str_function(desc)
 269 define_show_state_ull_function(above)
 270 define_show_state_ull_function(below)
 271
 272 static ssize_t show_state_time(struct cpuidle_state *state,
 273                                struct cpuidle_state_usage *state_usage,
 274                                char *buf)
 275 {
 276         return sprintf(buf, "%llu\n", ktime_to_us(state_usage->time_ns));
 277 }
 278
 279 static ssize_t show_state_disable(struct cpuidle_state *state,
 280                                   struct cpuidle_state_usage *state_usage,
 281                                   char *buf)
 282 {
 283         return sprintf(buf, "%llu\n",
 284                        state_usage->disable & CPUIDLE_STATE_DISABLED_BY_USER);
 285 }
 286
 287 static ssize_t store_state_disable(struct cpuidle_state *state,
 288                                    struct cpuidle_state_usage *state_usage,
 289                                    const char *buf, size_t size)
 290 {
 291         unsigned int value;
 292         int err;
 293
 294         if (!capable(CAP_SYS_ADMIN))
 295                 return -EPERM;
 296
 297         err = kstrtouint(buf, 0, &value);
 298         if (err)
 299                 return err;
 300
 301         if (value)
 302                 state_usage->disable |= CPUIDLE_STATE_DISABLED_BY_USER;
 303         else
 304                 state_usage->disable &= ~CPUIDLE_STATE_DISABLED_BY_USER;
 305
 306         return size;
 307 }
 308
 309 static ssize_t show_state_default_status(struct cpuidle_state *state,
 310                                           struct cpuidle_state_usage *state_usage,
 311                                           char *buf)
 312 {
 313         return sprintf(buf, "%s\n",
 314                        state->flags & CPUIDLE_FLAG_OFF ? "disabled" : "enabled");
 315 }
 316
 317 define_one_state_ro(name, show_state_name);
 318 define_one_state_ro(desc, show_state_desc);
 319 define_one_state_ro(latency, show_state_exit_latency);
 320 define_one_state_ro(residency, show_state_target_residency);
 321 define_one_state_ro(power, show_state_power_usage);
 322 define_one_state_ro(usage, show_state_usage);
 323 define_one_state_ro(rejected, show_state_rejected);
 324 define_one_state_ro(time, show_state_time);
 325 define_one_state_rw(disable, show_state_disable, store_state_disable);
 326 define_one_state_ro(above, show_state_above);
 327 define_one_state_ro(below, show_state_below);
 328 define_one_state_ro(default_status, show_state_default_status);
 329
 330 static struct attribute *cpuidle_state_default_attrs[] = {
 331         &attr_name.attr,
 332         &attr_desc.attr,
 333         &attr_latency.attr,
 334         &attr_residency.attr,
 335         &attr_power.attr,
 336         &attr_usage.attr,
 337         &attr_rejected.attr,
 338         &attr_time.attr,
 339         &attr_disable.attr,
 340         &attr_above.attr,
 341         &attr_below.attr,
 342         &attr_default_status.attr,
 343         NULL
 344 };
 345 ATTRIBUTE_GROUPS(cpuidle_state_default);
 346
 347 struct cpuidle_state_kobj {
 348         struct cpuidle_state *state;
 349         struct cpuidle_state_usage *state_usage;
 350         struct completion kobj_unregister;
 351         struct kobject kobj;
 352         struct cpuidle_device *device;
 353 };
 354
 355 #ifdef CONFIG_SUSPEND
 356 #define define_show_state_s2idle_ull_function(_name) \
 357 static ssize_t show_state_s2idle_##_name(struct cpuidle_state *state, \
 358                                          struct cpuidle_state_usage *state_usage, \
 359                                          char *buf)                             \
 360 { \
 361         return sprintf(buf, "%llu\n", state_usage->s2idle_##_name);\
 362 }
 363
 364 define_show_state_s2idle_ull_function(usage);
 365 define_show_state_s2idle_ull_function(time);
 366
 367 #define define_one_state_s2idle_ro(_name, show) \
 368 static struct cpuidle_state_attr attr_s2idle_##_name = \
 369         __ATTR(_name, 0444, show, NULL)
 370
 371 define_one_state_s2idle_ro(usage, show_state_s2idle_usage);
 372 define_one_state_s2idle_ro(time, show_state_s2idle_time);
 373
 374 static struct attribute *cpuidle_state_s2idle_attrs[] = {
 375         &attr_s2idle_usage.attr,
 376         &attr_s2idle_time.attr,
 377         NULL
 378 };
 379
 380 static const struct attribute_group cpuidle_state_s2idle_group = {
 381         .name   = "s2idle",
 382         .attrs  = cpuidle_state_s2idle_attrs,
 383 };
 384
 385 static void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
 386 {
 387         int ret;
 388
 389         if (!kobj->state->enter_s2idle)
 390                 return;
 391
 392         ret = sysfs_create_group(&kobj->kobj, &cpuidle_state_s2idle_group);
 393         if (ret)
 394                 pr_debug("%s: sysfs attribute group not created\n", __func__);
 395 }
 396
 397 static void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
 398 {
 399         if (kobj->state->enter_s2idle)
 400                 sysfs_remove_group(&kobj->kobj, &cpuidle_state_s2idle_group);
 401 }
 402 #else
 403 static inline void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
 404 static inline void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
 405 #endif /* CONFIG_SUSPEND */
 406
 407 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
 408 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
 409 #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
 410 #define kobj_to_device(k) (kobj_to_state_obj(k)->device)
 411 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
 412
 413 static ssize_t cpuidle_state_show(struct kobject *kobj, struct attribute *attr,
 414                                   char *buf)
 415 {
 416         int ret = -EIO;
 417         struct cpuidle_state *state = kobj_to_state(kobj);
 418         struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
 419         struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
 420
 421         if (cattr->show)
 422                 ret = cattr->show(state, state_usage, buf);
 423
 424         return ret;
 425 }
 426
 427 static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr,
 428                                    const char *buf, size_t size)
 429 {
 430         int ret = -EIO;
 431         struct cpuidle_state *state = kobj_to_state(kobj);
 432         struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
 433         struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
 434         struct cpuidle_device *dev = kobj_to_device(kobj);
 435
 436         if (cattr->store)
 437                 ret = cattr->store(state, state_usage, buf, size);
 438
 439         /* reset poll time cache */
 440         dev->poll_limit_ns = 0;
 441
 442         return ret;
 443 }
 444
 445 static const struct sysfs_ops cpuidle_state_sysfs_ops = {
 446         .show = cpuidle_state_show,
 447         .store = cpuidle_state_store,
 448 };
 449
 450 static void cpuidle_state_sysfs_release(struct kobject *kobj)
 451 {
 452         struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
 453
 454         complete(&state_obj->kobj_unregister);
 455 }
 456
 457 static const struct kobj_type ktype_state_cpuidle = {
 458         .sysfs_ops = &cpuidle_state_sysfs_ops,
 459         .default_groups = cpuidle_state_default_groups,
 460         .release = cpuidle_state_sysfs_release,
 461 };
 462
 463 static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
 464 {
 465         cpuidle_remove_s2idle_attr_group(device->kobjs[i]);
 466         kobject_put(&device->kobjs[i]->kobj);
 467         wait_for_completion(&device->kobjs[i]->kobj_unregister);
 468         kfree(device->kobjs[i]);
 469         device->kobjs[i] = NULL;
 470 }
 471
 472 /**
 473  * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes
 474  * @device: the target device
 475  */
 476 static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
 477 {
 478         int i, ret = -ENOMEM;
 479         struct cpuidle_state_kobj *kobj;
 480         struct cpuidle_device_kobj *kdev = device->kobj_dev;
 481         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
 482
 483         /* state statistics */
 484         for (i = 0; i < drv->state_count; i++) {
 485                 kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
 486                 if (!kobj) {
 487                         ret = -ENOMEM;
 488                         goto error_state;
 489                 }
 490                 kobj->state = &drv->states[i];
 491                 kobj->state_usage = &device->states_usage[i];
 492                 kobj->device = device;
 493                 init_completion(&kobj->kobj_unregister);
 494
 495                 ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
 496                                            &kdev->kobj, "state%d", i);
 497                 if (ret) {
 498                         kobject_put(&kobj->kobj);
 499                         kfree(kobj);
 500                         goto error_state;
 501                 }
 502                 cpuidle_add_s2idle_attr_group(kobj);
 503                 kobject_uevent(&kobj->kobj, KOBJ_ADD);
 504                 device->kobjs[i] = kobj;
 505         }
 506
 507         return 0;
 508
 509 error_state:
 510         for (i = i - 1; i >= 0; i--)
 511                 cpuidle_free_state_kobj(device, i);
 512         return ret;
 513 }
 514
 515 /**
 516  * cpuidle_remove_state_sysfs - removes the cpuidle states sysfs attributes
 517  * @device: the target device
 518  */
 519 static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
 520 {
 521         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
 522         int i;
 523
 524         for (i = 0; i < drv->state_count; i++)
 525                 cpuidle_free_state_kobj(device, i);
 526 }
 527
 528 #ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
 529 #define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
 530 #define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
 531
 532 #define define_one_driver_ro(_name, show)                       \
 533         static struct cpuidle_driver_attr attr_driver_##_name = \
 534                 __ATTR(_name, 0444, show, NULL)
 535
 536 struct cpuidle_driver_kobj {
 537         struct cpuidle_driver *drv;
 538         struct completion kobj_unregister;
 539         struct kobject kobj;
 540 };
 541
 542 struct cpuidle_driver_attr {
 543         struct attribute attr;
 544         ssize_t (*show)(struct cpuidle_driver *, char *);
 545         ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
 546 };
 547
 548 static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
 549 {
 550         ssize_t ret;
 551
 552         spin_lock(&cpuidle_driver_lock);
 553         ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
 554         spin_unlock(&cpuidle_driver_lock);
 555
 556         return ret;
 557 }
 558
 559 static void cpuidle_driver_sysfs_release(struct kobject *kobj)
 560 {
 561         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 562         complete(&driver_kobj->kobj_unregister);
 563 }
 564
 565 static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
 566                                    char *buf)
 567 {
 568         int ret = -EIO;
 569         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 570         struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
 571
 572         if (dattr->show)
 573                 ret = dattr->show(driver_kobj->drv, buf);
 574
 575         return ret;
 576 }
 577
 578 static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
 579                                     const char *buf, size_t size)
 580 {
 581         int ret = -EIO;
 582         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 583         struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
 584
 585         if (dattr->store)
 586                 ret = dattr->store(driver_kobj->drv, buf, size);
 587
 588         return ret;
 589 }
 590
 591 define_one_driver_ro(name, show_driver_name);
 592
 593 static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
 594         .show = cpuidle_driver_show,
 595         .store = cpuidle_driver_store,
 596 };
 597
 598 static struct attribute *cpuidle_driver_default_attrs[] = {
 599         &attr_driver_name.attr,
 600         NULL
 601 };
 602 ATTRIBUTE_GROUPS(cpuidle_driver_default);
 603
 604 static const struct kobj_type ktype_driver_cpuidle = {
 605         .sysfs_ops = &cpuidle_driver_sysfs_ops,
 606         .default_groups = cpuidle_driver_default_groups,
 607         .release = cpuidle_driver_sysfs_release,
 608 };
 609
 610 /**
 611  * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
 612  * @dev: the target device
 613  */
 614 static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 615 {
 616         struct cpuidle_driver_kobj *kdrv;
 617         struct cpuidle_device_kobj *kdev = dev->kobj_dev;
 618         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
 619         int ret;
 620
 621         kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
 622         if (!kdrv)
 623                 return -ENOMEM;
 624
 625         kdrv->drv = drv;
 626         init_completion(&kdrv->kobj_unregister);
 627
 628         ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
 629                                    &kdev->kobj, "driver");
 630         if (ret) {
 631                 kobject_put(&kdrv->kobj);
 632                 kfree(kdrv);
 633                 return ret;
 634         }
 635
 636         kobject_uevent(&kdrv->kobj, KOBJ_ADD);
 637         dev->kobj_driver = kdrv;
 638
 639         return ret;
 640 }
 641
 642 /**
 643  * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
 644  * @dev: the target device
 645  */
 646 static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
 647 {
 648         struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
 649         kobject_put(&kdrv->kobj);
 650         wait_for_completion(&kdrv->kobj_unregister);
 651         kfree(kdrv);
 652 }
 653 #else
 654 static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 655 {
 656         return 0;
 657 }
 658
 659 static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
 660 {
 661         ;
 662 }
 663 #endif
 664
 665 /**
 666  * cpuidle_add_device_sysfs - adds device specific sysfs attributes
 667  * @device: the target device
 668  */
 669 int cpuidle_add_device_sysfs(struct cpuidle_device *device)
 670 {
 671         int ret;
 672
 673         ret = cpuidle_add_state_sysfs(device);
 674         if (ret)
 675                 return ret;
 676
 677         ret = cpuidle_add_driver_sysfs(device);
 678         if (ret)
 679                 cpuidle_remove_state_sysfs(device);
 680         return ret;
 681 }
 682
 683 /**
 684  * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
 685  * @device : the target device
 686  */
 687 void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
 688 {
 689         cpuidle_remove_driver_sysfs(device);
 690         cpuidle_remove_state_sysfs(device);
 691 }
 692
 693 /**
 694  * cpuidle_add_sysfs - creates a sysfs instance for the target device
 695  * @dev: the target device
 696  */
 697 int cpuidle_add_sysfs(struct cpuidle_device *dev)
 698 {
 699         struct cpuidle_device_kobj *kdev;
 700         struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
 701         int error;
 702
 703         /*
 704          * Return if cpu_device is not setup for this CPU.
 705          *
 706          * This could happen if the arch did not set up cpu_device
 707          * since this CPU is not in cpu_present mask and the
 708          * driver did not send a correct CPU mask during registration.
 709          * Without this check we would end up passing bogus
 710          * value for &cpu_dev->kobj in kobject_init_and_add()
 711          */
 712         if (!cpu_dev)
 713                 return -ENODEV;
 714
 715         kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
 716         if (!kdev)
 717                 return -ENOMEM;
 718         kdev->dev = dev;
 719
 720         init_completion(&kdev->kobj_unregister);
 721
 722         error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
 723                                    "cpuidle");
 724         if (error) {
 725                 kobject_put(&kdev->kobj);
 726                 kfree(kdev);
 727                 return error;
 728         }
 729
 730         dev->kobj_dev = kdev;
 731         kobject_uevent(&kdev->kobj, KOBJ_ADD);
 732
 733         return 0;
 734 }
 735
 736 /**
 737  * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
 738  * @dev: the target device
 739  */
 740 void cpuidle_remove_sysfs(struct cpuidle_device *dev)
 741 {
 742         struct cpuidle_device_kobj *kdev = dev->kobj_dev;
 743
 744         kobject_put(&kdev->kobj);
 745         wait_for_completion(&kdev->kobj_unregister);
 746         kfree(kdev);
 747 }