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  * @dev: the target device
 146  */
 147 int cpuidle_add_interface(struct device *dev)
 148 {
 149         if (sysfs_switch)
 150                 cpuidle_attr_group.attrs = cpuidle_switch_attrs;
 151
 152         return sysfs_create_group(&dev->kobj, &cpuidle_attr_group);
 153 }
 154
 155 /**
 156  * cpuidle_remove_interface - remove CPU global sysfs attributes
 157  * @dev: the target device
 158  */
 159 void cpuidle_remove_interface(struct device *dev)
 160 {
 161         sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
 162 }
 163
 164 struct cpuidle_attr {
 165         struct attribute attr;
 166         ssize_t (*show)(struct cpuidle_device *, char *);
 167         ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
 168 };
 169
 170 #define define_one_ro(_name, show) \
 171         static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 172 #define define_one_rw(_name, show, store) \
 173         static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
 174
 175 #define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
 176
 177 struct cpuidle_device_kobj {
 178         struct cpuidle_device *dev;
 179         struct completion kobj_unregister;
 180         struct kobject kobj;
 181 };
 182
 183 static inline struct cpuidle_device *to_cpuidle_device(struct kobject *kobj)
 184 {
 185         struct cpuidle_device_kobj *kdev =
 186                 container_of(kobj, struct cpuidle_device_kobj, kobj);
 187
 188         return kdev->dev;
 189 }
 190
 191 static ssize_t cpuidle_show(struct kobject *kobj, struct attribute *attr,
 192                             char *buf)
 193 {
 194         int ret = -EIO;
 195         struct cpuidle_device *dev = to_cpuidle_device(kobj);
 196         struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
 197
 198         if (cattr->show) {
 199                 mutex_lock(&cpuidle_lock);
 200                 ret = cattr->show(dev, buf);
 201                 mutex_unlock(&cpuidle_lock);
 202         }
 203         return ret;
 204 }
 205
 206 static ssize_t cpuidle_store(struct kobject *kobj, struct attribute *attr,
 207                              const char *buf, size_t count)
 208 {
 209         int ret = -EIO;
 210         struct cpuidle_device *dev = to_cpuidle_device(kobj);
 211         struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
 212
 213         if (cattr->store) {
 214                 mutex_lock(&cpuidle_lock);
 215                 ret = cattr->store(dev, buf, count);
 216                 mutex_unlock(&cpuidle_lock);
 217         }
 218         return ret;
 219 }
 220
 221 static const struct sysfs_ops cpuidle_sysfs_ops = {
 222         .show = cpuidle_show,
 223         .store = cpuidle_store,
 224 };
 225
 226 static void cpuidle_sysfs_release(struct kobject *kobj)
 227 {
 228         struct cpuidle_device_kobj *kdev =
 229                 container_of(kobj, struct cpuidle_device_kobj, kobj);
 230
 231         complete(&kdev->kobj_unregister);
 232 }
 233
 234 static struct kobj_type ktype_cpuidle = {
 235         .sysfs_ops = &cpuidle_sysfs_ops,
 236         .release = cpuidle_sysfs_release,
 237 };
 238
 239 struct cpuidle_state_attr {
 240         struct attribute attr;
 241         ssize_t (*show)(struct cpuidle_state *, \
 242                                         struct cpuidle_state_usage *, char *);
 243         ssize_t (*store)(struct cpuidle_state *, \
 244                         struct cpuidle_state_usage *, const char *, size_t);
 245 };
 246
 247 #define define_one_state_ro(_name, show) \
 248 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 249
 250 #define define_one_state_rw(_name, show, store) \
 251 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
 252
 253 #define define_show_state_function(_name) \
 254 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 255                          struct cpuidle_state_usage *state_usage, char *buf) \
 256 { \
 257         return sprintf(buf, "%u\n", state->_name);\
 258 }
 259
 260 #define define_show_state_ull_function(_name) \
 261 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 262                                   struct cpuidle_state_usage *state_usage, \
 263                                   char *buf)                            \
 264 { \
 265         return sprintf(buf, "%llu\n", state_usage->_name);\
 266 }
 267
 268 #define define_show_state_str_function(_name) \
 269 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 270                                   struct cpuidle_state_usage *state_usage, \
 271                                   char *buf)                            \
 272 { \
 273         if (state->_name[0] == '\0')\
 274                 return sprintf(buf, "<null>\n");\
 275         return sprintf(buf, "%s\n", state->_name);\
 276 }
 277
 278 #define define_show_state_time_function(_name) \
 279 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 280                                   struct cpuidle_state_usage *state_usage, \
 281                                   char *buf) \
 282 { \
 283         return sprintf(buf, "%llu\n", ktime_to_us(state->_name##_ns)); \
 284 }
 285
 286 define_show_state_time_function(exit_latency)
 287 define_show_state_time_function(target_residency)
 288 define_show_state_function(power_usage)
 289 define_show_state_ull_function(usage)
 290 define_show_state_str_function(name)
 291 define_show_state_str_function(desc)
 292 define_show_state_ull_function(above)
 293 define_show_state_ull_function(below)
 294
 295 static ssize_t show_state_time(struct cpuidle_state *state,
 296                                struct cpuidle_state_usage *state_usage,
 297                                char *buf)
 298 {
 299         return sprintf(buf, "%llu\n", ktime_to_us(state_usage->time_ns));
 300 }
 301
 302 static ssize_t show_state_disable(struct cpuidle_state *state,
 303                                   struct cpuidle_state_usage *state_usage,
 304                                   char *buf)
 305 {
 306         return sprintf(buf, "%llu\n",
 307                        state_usage->disable & CPUIDLE_STATE_DISABLED_BY_USER);
 308 }
 309
 310 static ssize_t store_state_disable(struct cpuidle_state *state,
 311                                    struct cpuidle_state_usage *state_usage,
 312                                    const char *buf, size_t size)
 313 {
 314         unsigned int value;
 315         int err;
 316
 317         if (!capable(CAP_SYS_ADMIN))
 318                 return -EPERM;
 319
 320         err = kstrtouint(buf, 0, &value);
 321         if (err)
 322                 return err;
 323
 324         if (value)
 325                 state_usage->disable |= CPUIDLE_STATE_DISABLED_BY_USER;
 326         else
 327                 state_usage->disable &= ~CPUIDLE_STATE_DISABLED_BY_USER;
 328
 329         return size;
 330 }
 331
 332 static ssize_t show_state_default_status(struct cpuidle_state *state,
 333                                           struct cpuidle_state_usage *state_usage,
 334                                           char *buf)
 335 {
 336         return sprintf(buf, "%s\n",
 337                        state->flags & CPUIDLE_FLAG_OFF ? "disabled" : "enabled");
 338 }
 339
 340 define_one_state_ro(name, show_state_name);
 341 define_one_state_ro(desc, show_state_desc);
 342 define_one_state_ro(latency, show_state_exit_latency);
 343 define_one_state_ro(residency, show_state_target_residency);
 344 define_one_state_ro(power, show_state_power_usage);
 345 define_one_state_ro(usage, show_state_usage);
 346 define_one_state_ro(time, show_state_time);
 347 define_one_state_rw(disable, show_state_disable, store_state_disable);
 348 define_one_state_ro(above, show_state_above);
 349 define_one_state_ro(below, show_state_below);
 350 define_one_state_ro(default_status, show_state_default_status);
 351
 352 static struct attribute *cpuidle_state_default_attrs[] = {
 353         &attr_name.attr,
 354         &attr_desc.attr,
 355         &attr_latency.attr,
 356         &attr_residency.attr,
 357         &attr_power.attr,
 358         &attr_usage.attr,
 359         &attr_time.attr,
 360         &attr_disable.attr,
 361         &attr_above.attr,
 362         &attr_below.attr,
 363         &attr_default_status.attr,
 364         NULL
 365 };
 366
 367 struct cpuidle_state_kobj {
 368         struct cpuidle_state *state;
 369         struct cpuidle_state_usage *state_usage;
 370         struct completion kobj_unregister;
 371         struct kobject kobj;
 372         struct cpuidle_device *device;
 373 };
 374
 375 #ifdef CONFIG_SUSPEND
 376 #define define_show_state_s2idle_ull_function(_name) \
 377 static ssize_t show_state_s2idle_##_name(struct cpuidle_state *state, \
 378                                          struct cpuidle_state_usage *state_usage, \
 379                                          char *buf)                             \
 380 { \
 381         return sprintf(buf, "%llu\n", state_usage->s2idle_##_name);\
 382 }
 383
 384 define_show_state_s2idle_ull_function(usage);
 385 define_show_state_s2idle_ull_function(time);
 386
 387 #define define_one_state_s2idle_ro(_name, show) \
 388 static struct cpuidle_state_attr attr_s2idle_##_name = \
 389         __ATTR(_name, 0444, show, NULL)
 390
 391 define_one_state_s2idle_ro(usage, show_state_s2idle_usage);
 392 define_one_state_s2idle_ro(time, show_state_s2idle_time);
 393
 394 static struct attribute *cpuidle_state_s2idle_attrs[] = {
 395         &attr_s2idle_usage.attr,
 396         &attr_s2idle_time.attr,
 397         NULL
 398 };
 399
 400 static const struct attribute_group cpuidle_state_s2idle_group = {
 401         .name   = "s2idle",
 402         .attrs  = cpuidle_state_s2idle_attrs,
 403 };
 404
 405 static void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
 406 {
 407         int ret;
 408
 409         if (!kobj->state->enter_s2idle)
 410                 return;
 411
 412         ret = sysfs_create_group(&kobj->kobj, &cpuidle_state_s2idle_group);
 413         if (ret)
 414                 pr_debug("%s: sysfs attribute group not created\n", __func__);
 415 }
 416
 417 static void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
 418 {
 419         if (kobj->state->enter_s2idle)
 420                 sysfs_remove_group(&kobj->kobj, &cpuidle_state_s2idle_group);
 421 }
 422 #else
 423 static inline void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
 424 static inline void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
 425 #endif /* CONFIG_SUSPEND */
 426
 427 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
 428 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
 429 #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
 430 #define kobj_to_device(k) (kobj_to_state_obj(k)->device)
 431 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
 432
 433 static ssize_t cpuidle_state_show(struct kobject *kobj, struct attribute *attr,
 434                                   char * buf)
 435 {
 436         int ret = -EIO;
 437         struct cpuidle_state *state = kobj_to_state(kobj);
 438         struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
 439         struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
 440
 441         if (cattr->show)
 442                 ret = cattr->show(state, state_usage, buf);
 443
 444         return ret;
 445 }
 446
 447 static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr,
 448                                    const char *buf, size_t size)
 449 {
 450         int ret = -EIO;
 451         struct cpuidle_state *state = kobj_to_state(kobj);
 452         struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
 453         struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
 454         struct cpuidle_device *dev = kobj_to_device(kobj);
 455
 456         if (cattr->store)
 457                 ret = cattr->store(state, state_usage, buf, size);
 458
 459         /* reset poll time cache */
 460         dev->poll_limit_ns = 0;
 461
 462         return ret;
 463 }
 464
 465 static const struct sysfs_ops cpuidle_state_sysfs_ops = {
 466         .show = cpuidle_state_show,
 467         .store = cpuidle_state_store,
 468 };
 469
 470 static void cpuidle_state_sysfs_release(struct kobject *kobj)
 471 {
 472         struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
 473
 474         complete(&state_obj->kobj_unregister);
 475 }
 476
 477 static struct kobj_type ktype_state_cpuidle = {
 478         .sysfs_ops = &cpuidle_state_sysfs_ops,
 479         .default_attrs = cpuidle_state_default_attrs,
 480         .release = cpuidle_state_sysfs_release,
 481 };
 482
 483 static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
 484 {
 485         cpuidle_remove_s2idle_attr_group(device->kobjs[i]);
 486         kobject_put(&device->kobjs[i]->kobj);
 487         wait_for_completion(&device->kobjs[i]->kobj_unregister);
 488         kfree(device->kobjs[i]);
 489         device->kobjs[i] = NULL;
 490 }
 491
 492 /**
 493  * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes
 494  * @device: the target device
 495  */
 496 static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
 497 {
 498         int i, ret = -ENOMEM;
 499         struct cpuidle_state_kobj *kobj;
 500         struct cpuidle_device_kobj *kdev = device->kobj_dev;
 501         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
 502
 503         /* state statistics */
 504         for (i = 0; i < drv->state_count; i++) {
 505                 kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
 506                 if (!kobj) {
 507                         ret = -ENOMEM;
 508                         goto error_state;
 509                 }
 510                 kobj->state = &drv->states[i];
 511                 kobj->state_usage = &device->states_usage[i];
 512                 kobj->device = device;
 513                 init_completion(&kobj->kobj_unregister);
 514
 515                 ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
 516                                            &kdev->kobj, "state%d", i);
 517                 if (ret) {
 518                         kfree(kobj);
 519                         goto error_state;
 520                 }
 521                 cpuidle_add_s2idle_attr_group(kobj);
 522                 kobject_uevent(&kobj->kobj, KOBJ_ADD);
 523                 device->kobjs[i] = kobj;
 524         }
 525
 526         return 0;
 527
 528 error_state:
 529         for (i = i - 1; i >= 0; i--)
 530                 cpuidle_free_state_kobj(device, i);
 531         return ret;
 532 }
 533
 534 /**
 535  * cpuidle_remove_driver_sysfs - removes the cpuidle states sysfs attributes
 536  * @device: the target device
 537  */
 538 static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
 539 {
 540         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
 541         int i;
 542
 543         for (i = 0; i < drv->state_count; i++)
 544                 cpuidle_free_state_kobj(device, i);
 545 }
 546
 547 #ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
 548 #define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
 549 #define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
 550
 551 #define define_one_driver_ro(_name, show)                       \
 552         static struct cpuidle_driver_attr attr_driver_##_name = \
 553                 __ATTR(_name, 0444, show, NULL)
 554
 555 struct cpuidle_driver_kobj {
 556         struct cpuidle_driver *drv;
 557         struct completion kobj_unregister;
 558         struct kobject kobj;
 559 };
 560
 561 struct cpuidle_driver_attr {
 562         struct attribute attr;
 563         ssize_t (*show)(struct cpuidle_driver *, char *);
 564         ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
 565 };
 566
 567 static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
 568 {
 569         ssize_t ret;
 570
 571         spin_lock(&cpuidle_driver_lock);
 572         ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
 573         spin_unlock(&cpuidle_driver_lock);
 574
 575         return ret;
 576 }
 577
 578 static void cpuidle_driver_sysfs_release(struct kobject *kobj)
 579 {
 580         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 581         complete(&driver_kobj->kobj_unregister);
 582 }
 583
 584 static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
 585                                    char *buf)
 586 {
 587         int ret = -EIO;
 588         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 589         struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
 590
 591         if (dattr->show)
 592                 ret = dattr->show(driver_kobj->drv, buf);
 593
 594         return ret;
 595 }
 596
 597 static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
 598                                     const char *buf, size_t size)
 599 {
 600         int ret = -EIO;
 601         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 602         struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
 603
 604         if (dattr->store)
 605                 ret = dattr->store(driver_kobj->drv, buf, size);
 606
 607         return ret;
 608 }
 609
 610 define_one_driver_ro(name, show_driver_name);
 611
 612 static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
 613         .show = cpuidle_driver_show,
 614         .store = cpuidle_driver_store,
 615 };
 616
 617 static struct attribute *cpuidle_driver_default_attrs[] = {
 618         &attr_driver_name.attr,
 619         NULL
 620 };
 621
 622 static struct kobj_type ktype_driver_cpuidle = {
 623         .sysfs_ops = &cpuidle_driver_sysfs_ops,
 624         .default_attrs = cpuidle_driver_default_attrs,
 625         .release = cpuidle_driver_sysfs_release,
 626 };
 627
 628 /**
 629  * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
 630  * @dev: the target device
 631  */
 632 static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 633 {
 634         struct cpuidle_driver_kobj *kdrv;
 635         struct cpuidle_device_kobj *kdev = dev->kobj_dev;
 636         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
 637         int ret;
 638
 639         kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
 640         if (!kdrv)
 641                 return -ENOMEM;
 642
 643         kdrv->drv = drv;
 644         init_completion(&kdrv->kobj_unregister);
 645
 646         ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
 647                                    &kdev->kobj, "driver");
 648         if (ret) {
 649                 kfree(kdrv);
 650                 return ret;
 651         }
 652
 653         kobject_uevent(&kdrv->kobj, KOBJ_ADD);
 654         dev->kobj_driver = kdrv;
 655
 656         return ret;
 657 }
 658
 659 /**
 660  * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
 661  * @dev: the target device
 662  */
 663 static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
 664 {
 665         struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
 666         kobject_put(&kdrv->kobj);
 667         wait_for_completion(&kdrv->kobj_unregister);
 668         kfree(kdrv);
 669 }
 670 #else
 671 static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 672 {
 673         return 0;
 674 }
 675
 676 static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
 677 {
 678         ;
 679 }
 680 #endif
 681
 682 /**
 683  * cpuidle_add_device_sysfs - adds device specific sysfs attributes
 684  * @device: the target device
 685  */
 686 int cpuidle_add_device_sysfs(struct cpuidle_device *device)
 687 {
 688         int ret;
 689
 690         ret = cpuidle_add_state_sysfs(device);
 691         if (ret)
 692                 return ret;
 693
 694         ret = cpuidle_add_driver_sysfs(device);
 695         if (ret)
 696                 cpuidle_remove_state_sysfs(device);
 697         return ret;
 698 }
 699
 700 /**
 701  * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
 702  * @device : the target device
 703  */
 704 void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
 705 {
 706         cpuidle_remove_driver_sysfs(device);
 707         cpuidle_remove_state_sysfs(device);
 708 }
 709
 710 /**
 711  * cpuidle_add_sysfs - creates a sysfs instance for the target device
 712  * @dev: the target device
 713  */
 714 int cpuidle_add_sysfs(struct cpuidle_device *dev)
 715 {
 716         struct cpuidle_device_kobj *kdev;
 717         struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
 718         int error;
 719
 720         /*
 721          * Return if cpu_device is not setup for this CPU.
 722          *
 723          * This could happen if the arch did not set up cpu_device
 724          * since this CPU is not in cpu_present mask and the
 725          * driver did not send a correct CPU mask during registration.
 726          * Without this check we would end up passing bogus
 727          * value for &cpu_dev->kobj in kobject_init_and_add()
 728          */
 729         if (!cpu_dev)
 730                 return -ENODEV;
 731
 732         kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
 733         if (!kdev)
 734                 return -ENOMEM;
 735         kdev->dev = dev;
 736         dev->kobj_dev = kdev;
 737
 738         init_completion(&kdev->kobj_unregister);
 739
 740         error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
 741                                    "cpuidle");
 742         if (error) {
 743                 kfree(kdev);
 744                 return error;
 745         }
 746
 747         kobject_uevent(&kdev->kobj, KOBJ_ADD);
 748
 749         return 0;
 750 }
 751
 752 /**
 753  * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
 754  * @dev: the target device
 755  */
 756 void cpuidle_remove_sysfs(struct cpuidle_device *dev)
 757 {
 758         struct cpuidle_device_kobj *kdev = dev->kobj_dev;
 759
 760         kobject_put(&kdev->kobj);
 761         wait_for_completion(&kdev->kobj_unregister);
 762         kfree(kdev);
 763 }