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_ull_function(rejected)
 260 define_show_state_str_function(name)
 261 define_show_state_str_function(desc)
 262 define_show_state_ull_function(above)
 263 define_show_state_ull_function(below)
 264
 265 static ssize_t show_state_time(struct cpuidle_state *state,
 266                                struct cpuidle_state_usage *state_usage,
 267                                char *buf)
 268 {
 269         return sprintf(buf, "%llu\n", ktime_to_us(state_usage->time_ns));
 270 }
 271
 272 static ssize_t show_state_disable(struct cpuidle_state *state,
 273                                   struct cpuidle_state_usage *state_usage,
 274                                   char *buf)
 275 {
 276         return sprintf(buf, "%llu\n",
 277                        state_usage->disable & CPUIDLE_STATE_DISABLED_BY_USER);
 278 }
 279
 280 static ssize_t store_state_disable(struct cpuidle_state *state,
 281                                    struct cpuidle_state_usage *state_usage,
 282                                    const char *buf, size_t size)
 283 {
 284         unsigned int value;
 285         int err;
 286
 287         if (!capable(CAP_SYS_ADMIN))
 288                 return -EPERM;
 289
 290         err = kstrtouint(buf, 0, &value);
 291         if (err)
 292                 return err;
 293
 294         if (value)
 295                 state_usage->disable |= CPUIDLE_STATE_DISABLED_BY_USER;
 296         else
 297                 state_usage->disable &= ~CPUIDLE_STATE_DISABLED_BY_USER;
 298
 299         return size;
 300 }
 301
 302 static ssize_t show_state_default_status(struct cpuidle_state *state,
 303                                           struct cpuidle_state_usage *state_usage,
 304                                           char *buf)
 305 {
 306         return sprintf(buf, "%s\n",
 307                        state->flags & CPUIDLE_FLAG_OFF ? "disabled" : "enabled");
 308 }
 309
 310 define_one_state_ro(name, show_state_name);
 311 define_one_state_ro(desc, show_state_desc);
 312 define_one_state_ro(latency, show_state_exit_latency);
 313 define_one_state_ro(residency, show_state_target_residency);
 314 define_one_state_ro(power, show_state_power_usage);
 315 define_one_state_ro(usage, show_state_usage);
 316 define_one_state_ro(rejected, show_state_rejected);
 317 define_one_state_ro(time, show_state_time);
 318 define_one_state_rw(disable, show_state_disable, store_state_disable);
 319 define_one_state_ro(above, show_state_above);
 320 define_one_state_ro(below, show_state_below);
 321 define_one_state_ro(default_status, show_state_default_status);
 322
 323 static struct attribute *cpuidle_state_default_attrs[] = {
 324         &attr_name.attr,
 325         &attr_desc.attr,
 326         &attr_latency.attr,
 327         &attr_residency.attr,
 328         &attr_power.attr,
 329         &attr_usage.attr,
 330         &attr_rejected.attr,
 331         &attr_time.attr,
 332         &attr_disable.attr,
 333         &attr_above.attr,
 334         &attr_below.attr,
 335         &attr_default_status.attr,
 336         NULL
 337 };
 338 ATTRIBUTE_GROUPS(cpuidle_state_default);
 339
 340 struct cpuidle_state_kobj {
 341         struct cpuidle_state *state;
 342         struct cpuidle_state_usage *state_usage;
 343         struct completion kobj_unregister;
 344         struct kobject kobj;
 345         struct cpuidle_device *device;
 346 };
 347
 348 #ifdef CONFIG_SUSPEND
 349 #define define_show_state_s2idle_ull_function(_name) \
 350 static ssize_t show_state_s2idle_##_name(struct cpuidle_state *state, \
 351                                          struct cpuidle_state_usage *state_usage, \
 352                                          char *buf)                             \
 353 { \
 354         return sprintf(buf, "%llu\n", state_usage->s2idle_##_name);\
 355 }
 356
 357 define_show_state_s2idle_ull_function(usage);
 358 define_show_state_s2idle_ull_function(time);
 359
 360 #define define_one_state_s2idle_ro(_name, show) \
 361 static struct cpuidle_state_attr attr_s2idle_##_name = \
 362         __ATTR(_name, 0444, show, NULL)
 363
 364 define_one_state_s2idle_ro(usage, show_state_s2idle_usage);
 365 define_one_state_s2idle_ro(time, show_state_s2idle_time);
 366
 367 static struct attribute *cpuidle_state_s2idle_attrs[] = {
 368         &attr_s2idle_usage.attr,
 369         &attr_s2idle_time.attr,
 370         NULL
 371 };
 372
 373 static const struct attribute_group cpuidle_state_s2idle_group = {
 374         .name   = "s2idle",
 375         .attrs  = cpuidle_state_s2idle_attrs,
 376 };
 377
 378 static void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
 379 {
 380         int ret;
 381
 382         if (!kobj->state->enter_s2idle)
 383                 return;
 384
 385         ret = sysfs_create_group(&kobj->kobj, &cpuidle_state_s2idle_group);
 386         if (ret)
 387                 pr_debug("%s: sysfs attribute group not created\n", __func__);
 388 }
 389
 390 static void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
 391 {
 392         if (kobj->state->enter_s2idle)
 393                 sysfs_remove_group(&kobj->kobj, &cpuidle_state_s2idle_group);
 394 }
 395 #else
 396 static inline void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
 397 static inline void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
 398 #endif /* CONFIG_SUSPEND */
 399
 400 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
 401 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
 402 #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
 403 #define kobj_to_device(k) (kobj_to_state_obj(k)->device)
 404 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
 405
 406 static ssize_t cpuidle_state_show(struct kobject *kobj, struct attribute *attr,
 407                                   char *buf)
 408 {
 409         int ret = -EIO;
 410         struct cpuidle_state *state = kobj_to_state(kobj);
 411         struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
 412         struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
 413
 414         if (cattr->show)
 415                 ret = cattr->show(state, state_usage, buf);
 416
 417         return ret;
 418 }
 419
 420 static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr,
 421                                    const char *buf, size_t size)
 422 {
 423         int ret = -EIO;
 424         struct cpuidle_state *state = kobj_to_state(kobj);
 425         struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
 426         struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
 427         struct cpuidle_device *dev = kobj_to_device(kobj);
 428
 429         if (cattr->store)
 430                 ret = cattr->store(state, state_usage, buf, size);
 431
 432         /* reset poll time cache */
 433         dev->poll_limit_ns = 0;
 434
 435         return ret;
 436 }
 437
 438 static const struct sysfs_ops cpuidle_state_sysfs_ops = {
 439         .show = cpuidle_state_show,
 440         .store = cpuidle_state_store,
 441 };
 442
 443 static void cpuidle_state_sysfs_release(struct kobject *kobj)
 444 {
 445         struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
 446
 447         complete(&state_obj->kobj_unregister);
 448 }
 449
 450 static struct kobj_type ktype_state_cpuidle = {
 451         .sysfs_ops = &cpuidle_state_sysfs_ops,
 452         .default_groups = cpuidle_state_default_groups,
 453         .release = cpuidle_state_sysfs_release,
 454 };
 455
 456 static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
 457 {
 458         cpuidle_remove_s2idle_attr_group(device->kobjs[i]);
 459         kobject_put(&device->kobjs[i]->kobj);
 460         wait_for_completion(&device->kobjs[i]->kobj_unregister);
 461         kfree(device->kobjs[i]);
 462         device->kobjs[i] = NULL;
 463 }
 464
 465 /**
 466  * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes
 467  * @device: the target device
 468  */
 469 static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
 470 {
 471         int i, ret = -ENOMEM;
 472         struct cpuidle_state_kobj *kobj;
 473         struct cpuidle_device_kobj *kdev = device->kobj_dev;
 474         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
 475
 476         /* state statistics */
 477         for (i = 0; i < drv->state_count; i++) {
 478                 kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
 479                 if (!kobj) {
 480                         ret = -ENOMEM;
 481                         goto error_state;
 482                 }
 483                 kobj->state = &drv->states[i];
 484                 kobj->state_usage = &device->states_usage[i];
 485                 kobj->device = device;
 486                 init_completion(&kobj->kobj_unregister);
 487
 488                 ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
 489                                            &kdev->kobj, "state%d", i);
 490                 if (ret) {
 491                         kobject_put(&kobj->kobj);
 492                         kfree(kobj);
 493                         goto error_state;
 494                 }
 495                 cpuidle_add_s2idle_attr_group(kobj);
 496                 kobject_uevent(&kobj->kobj, KOBJ_ADD);
 497                 device->kobjs[i] = kobj;
 498         }
 499
 500         return 0;
 501
 502 error_state:
 503         for (i = i - 1; i >= 0; i--)
 504                 cpuidle_free_state_kobj(device, i);
 505         return ret;
 506 }
 507
 508 /**
 509  * cpuidle_remove_state_sysfs - removes the cpuidle states sysfs attributes
 510  * @device: the target device
 511  */
 512 static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
 513 {
 514         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
 515         int i;
 516
 517         for (i = 0; i < drv->state_count; i++)
 518                 cpuidle_free_state_kobj(device, i);
 519 }
 520
 521 #ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
 522 #define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
 523 #define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
 524
 525 #define define_one_driver_ro(_name, show)                       \
 526         static struct cpuidle_driver_attr attr_driver_##_name = \
 527                 __ATTR(_name, 0444, show, NULL)
 528
 529 struct cpuidle_driver_kobj {
 530         struct cpuidle_driver *drv;
 531         struct completion kobj_unregister;
 532         struct kobject kobj;
 533 };
 534
 535 struct cpuidle_driver_attr {
 536         struct attribute attr;
 537         ssize_t (*show)(struct cpuidle_driver *, char *);
 538         ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
 539 };
 540
 541 static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
 542 {
 543         ssize_t ret;
 544
 545         spin_lock(&cpuidle_driver_lock);
 546         ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
 547         spin_unlock(&cpuidle_driver_lock);
 548
 549         return ret;
 550 }
 551
 552 static void cpuidle_driver_sysfs_release(struct kobject *kobj)
 553 {
 554         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 555         complete(&driver_kobj->kobj_unregister);
 556 }
 557
 558 static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
 559                                    char *buf)
 560 {
 561         int ret = -EIO;
 562         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 563         struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
 564
 565         if (dattr->show)
 566                 ret = dattr->show(driver_kobj->drv, buf);
 567
 568         return ret;
 569 }
 570
 571 static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
 572                                     const char *buf, size_t size)
 573 {
 574         int ret = -EIO;
 575         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 576         struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
 577
 578         if (dattr->store)
 579                 ret = dattr->store(driver_kobj->drv, buf, size);
 580
 581         return ret;
 582 }
 583
 584 define_one_driver_ro(name, show_driver_name);
 585
 586 static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
 587         .show = cpuidle_driver_show,
 588         .store = cpuidle_driver_store,
 589 };
 590
 591 static struct attribute *cpuidle_driver_default_attrs[] = {
 592         &attr_driver_name.attr,
 593         NULL
 594 };
 595 ATTRIBUTE_GROUPS(cpuidle_driver_default);
 596
 597 static struct kobj_type ktype_driver_cpuidle = {
 598         .sysfs_ops = &cpuidle_driver_sysfs_ops,
 599         .default_groups = cpuidle_driver_default_groups,
 600         .release = cpuidle_driver_sysfs_release,
 601 };
 602
 603 /**
 604  * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
 605  * @dev: the target device
 606  */
 607 static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 608 {
 609         struct cpuidle_driver_kobj *kdrv;
 610         struct cpuidle_device_kobj *kdev = dev->kobj_dev;
 611         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
 612         int ret;
 613
 614         kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
 615         if (!kdrv)
 616                 return -ENOMEM;
 617
 618         kdrv->drv = drv;
 619         init_completion(&kdrv->kobj_unregister);
 620
 621         ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
 622                                    &kdev->kobj, "driver");
 623         if (ret) {
 624                 kobject_put(&kdrv->kobj);
 625                 kfree(kdrv);
 626                 return ret;
 627         }
 628
 629         kobject_uevent(&kdrv->kobj, KOBJ_ADD);
 630         dev->kobj_driver = kdrv;
 631
 632         return ret;
 633 }
 634
 635 /**
 636  * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
 637  * @dev: the target device
 638  */
 639 static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
 640 {
 641         struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
 642         kobject_put(&kdrv->kobj);
 643         wait_for_completion(&kdrv->kobj_unregister);
 644         kfree(kdrv);
 645 }
 646 #else
 647 static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 648 {
 649         return 0;
 650 }
 651
 652 static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
 653 {
 654         ;
 655 }
 656 #endif
 657
 658 /**
 659  * cpuidle_add_device_sysfs - adds device specific sysfs attributes
 660  * @device: the target device
 661  */
 662 int cpuidle_add_device_sysfs(struct cpuidle_device *device)
 663 {
 664         int ret;
 665
 666         ret = cpuidle_add_state_sysfs(device);
 667         if (ret)
 668                 return ret;
 669
 670         ret = cpuidle_add_driver_sysfs(device);
 671         if (ret)
 672                 cpuidle_remove_state_sysfs(device);
 673         return ret;
 674 }
 675
 676 /**
 677  * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
 678  * @device : the target device
 679  */
 680 void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
 681 {
 682         cpuidle_remove_driver_sysfs(device);
 683         cpuidle_remove_state_sysfs(device);
 684 }
 685
 686 /**
 687  * cpuidle_add_sysfs - creates a sysfs instance for the target device
 688  * @dev: the target device
 689  */
 690 int cpuidle_add_sysfs(struct cpuidle_device *dev)
 691 {
 692         struct cpuidle_device_kobj *kdev;
 693         struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
 694         int error;
 695
 696         /*
 697          * Return if cpu_device is not setup for this CPU.
 698          *
 699          * This could happen if the arch did not set up cpu_device
 700          * since this CPU is not in cpu_present mask and the
 701          * driver did not send a correct CPU mask during registration.
 702          * Without this check we would end up passing bogus
 703          * value for &cpu_dev->kobj in kobject_init_and_add()
 704          */
 705         if (!cpu_dev)
 706                 return -ENODEV;
 707
 708         kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
 709         if (!kdev)
 710                 return -ENOMEM;
 711         kdev->dev = dev;
 712
 713         init_completion(&kdev->kobj_unregister);
 714
 715         error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
 716                                    "cpuidle");
 717         if (error) {
 718                 kobject_put(&kdev->kobj);
 719                 kfree(kdev);
 720                 return error;
 721         }
 722
 723         dev->kobj_dev = kdev;
 724         kobject_uevent(&kdev->kobj, KOBJ_ADD);
 725
 726         return 0;
 727 }
 728
 729 /**
 730  * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
 731  * @dev: the target device
 732  */
 733 void cpuidle_remove_sysfs(struct cpuidle_device *dev)
 734 {
 735         struct cpuidle_device_kobj *kdev = dev->kobj_dev;
 736
 737         kobject_put(&kdev->kobj);
 738         wait_for_completion(&kdev->kobj_unregister);
 739         kfree(kdev);
 740 }