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