drivers/cpuidle/sysfs.c

   1 /*
   2  * sysfs.c - sysfs support
   3  *
   4  * (C) 2006-2007 Shaohua Li <[email protected]>
   5  *
   6  * This code is licenced under the GPL.
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/cpuidle.h>
  11 #include <linux/sysfs.h>
  12 #include <linux/slab.h>
  13 #include <linux/cpu.h>
  14 #include <linux/completion.h>
  15 #include <linux/capability.h>
  16 #include <linux/device.h>
  17 #include <linux/kobject.h>
  18
  19 #include "cpuidle.h"
  20
  21 static unsigned int sysfs_switch;
  22 static int __init cpuidle_sysfs_setup(char *unused)
  23 {
  24         sysfs_switch = 1;
  25         return 1;
  26 }
  27 __setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);
  28
  29 static ssize_t show_available_governors(struct device *dev,
  30                                         struct device_attribute *attr,
  31                                         char *buf)
  32 {
  33         ssize_t i = 0;
  34         struct cpuidle_governor *tmp;
  35
  36         mutex_lock(&cpuidle_lock);
  37         list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
  38                 if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) -
  39                                     CPUIDLE_NAME_LEN - 2))
  40                         goto out;
  41                 i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
  42         }
  43
  44 out:
  45         i+= sprintf(&buf[i], "\n");
  46         mutex_unlock(&cpuidle_lock);
  47         return i;
  48 }
  49
  50 static ssize_t show_current_driver(struct device *dev,
  51                                    struct device_attribute *attr,
  52                                    char *buf)
  53 {
  54         ssize_t ret;
  55         struct cpuidle_driver *drv;
  56
  57         spin_lock(&cpuidle_driver_lock);
  58         drv = cpuidle_get_driver();
  59         if (drv)
  60                 ret = sprintf(buf, "%s\n", drv->name);
  61         else
  62                 ret = sprintf(buf, "none\n");
  63         spin_unlock(&cpuidle_driver_lock);
  64
  65         return ret;
  66 }
  67
  68 static ssize_t show_current_governor(struct device *dev,
  69                                      struct device_attribute *attr,
  70                                      char *buf)
  71 {
  72         ssize_t ret;
  73
  74         mutex_lock(&cpuidle_lock);
  75         if (cpuidle_curr_governor)
  76                 ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
  77         else
  78                 ret = sprintf(buf, "none\n");
  79         mutex_unlock(&cpuidle_lock);
  80
  81         return ret;
  82 }
  83
  84 static ssize_t store_current_governor(struct device *dev,
  85                                       struct device_attribute *attr,
  86                                       const char *buf, size_t count)
  87 {
  88         char gov_name[CPUIDLE_NAME_LEN];
  89         int ret = -EINVAL;
  90         size_t len = count;
  91         struct cpuidle_governor *gov;
  92
  93         if (!len || len >= sizeof(gov_name))
  94                 return -EINVAL;
  95
  96         memcpy(gov_name, buf, len);
  97         gov_name[len] = '\0';
  98         if (gov_name[len - 1] == '\n')
  99                 gov_name[--len] = '\0';
 100
 101         mutex_lock(&cpuidle_lock);
 102
 103         list_for_each_entry(gov, &cpuidle_governors, governor_list) {
 104                 if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
 105                         ret = cpuidle_switch_governor(gov);
 106                         break;
 107                 }
 108         }
 109
 110         mutex_unlock(&cpuidle_lock);
 111
 112         if (ret)
 113                 return ret;
 114         else
 115                 return count;
 116 }
 117
 118 static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
 119 static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
 120
 121 static struct attribute *cpuidle_default_attrs[] = {
 122         &dev_attr_current_driver.attr,
 123         &dev_attr_current_governor_ro.attr,
 124         NULL
 125 };
 126
 127 static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
 128 static DEVICE_ATTR(current_governor, 0644, show_current_governor,
 129                    store_current_governor);
 130
 131 static struct attribute *cpuidle_switch_attrs[] = {
 132         &dev_attr_available_governors.attr,
 133         &dev_attr_current_driver.attr,
 134         &dev_attr_current_governor.attr,
 135         NULL
 136 };
 137
 138 static struct attribute_group cpuidle_attr_group = {
 139         .attrs = cpuidle_default_attrs,
 140         .name = "cpuidle",
 141 };
 142
 143 /**
 144  * cpuidle_add_interface - add CPU global sysfs attributes
 145  */
 146 int cpuidle_add_interface(struct device *dev)
 147 {
 148         if (sysfs_switch)
 149                 cpuidle_attr_group.attrs = cpuidle_switch_attrs;
 150
 151         return sysfs_create_group(&dev->kobj, &cpuidle_attr_group);
 152 }
 153
 154 /**
 155  * cpuidle_remove_interface - remove CPU global sysfs attributes
 156  */
 157 void cpuidle_remove_interface(struct device *dev)
 158 {
 159         sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
 160 }
 161
 162 struct cpuidle_attr {
 163         struct attribute attr;
 164         ssize_t (*show)(struct cpuidle_device *, char *);
 165         ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
 166 };
 167
 168 #define define_one_ro(_name, show) \
 169         static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 170 #define define_one_rw(_name, show, store) \
 171         static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
 172
 173 #define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
 174
 175 struct cpuidle_device_kobj {
 176         struct cpuidle_device *dev;
 177         struct completion kobj_unregister;
 178         struct kobject kobj;
 179 };
 180
 181 static inline struct cpuidle_device *to_cpuidle_device(struct kobject *kobj)
 182 {
 183         struct cpuidle_device_kobj *kdev =
 184                 container_of(kobj, struct cpuidle_device_kobj, kobj);
 185
 186         return kdev->dev;
 187 }
 188
 189 static ssize_t cpuidle_show(struct kobject *kobj, struct attribute *attr,
 190                             char *buf)
 191 {
 192         int ret = -EIO;
 193         struct cpuidle_device *dev = to_cpuidle_device(kobj);
 194         struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
 195
 196         if (cattr->show) {
 197                 mutex_lock(&cpuidle_lock);
 198                 ret = cattr->show(dev, buf);
 199                 mutex_unlock(&cpuidle_lock);
 200         }
 201         return ret;
 202 }
 203
 204 static ssize_t cpuidle_store(struct kobject *kobj, struct attribute *attr,
 205                              const char *buf, size_t count)
 206 {
 207         int ret = -EIO;
 208         struct cpuidle_device *dev = to_cpuidle_device(kobj);
 209         struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
 210
 211         if (cattr->store) {
 212                 mutex_lock(&cpuidle_lock);
 213                 ret = cattr->store(dev, buf, count);
 214                 mutex_unlock(&cpuidle_lock);
 215         }
 216         return ret;
 217 }
 218
 219 static const struct sysfs_ops cpuidle_sysfs_ops = {
 220         .show = cpuidle_show,
 221         .store = cpuidle_store,
 222 };
 223
 224 static void cpuidle_sysfs_release(struct kobject *kobj)
 225 {
 226         struct cpuidle_device_kobj *kdev =
 227                 container_of(kobj, struct cpuidle_device_kobj, kobj);
 228
 229         complete(&kdev->kobj_unregister);
 230 }
 231
 232 static struct kobj_type ktype_cpuidle = {
 233         .sysfs_ops = &cpuidle_sysfs_ops,
 234         .release = cpuidle_sysfs_release,
 235 };
 236
 237 struct cpuidle_state_attr {
 238         struct attribute attr;
 239         ssize_t (*show)(struct cpuidle_state *, \
 240                                         struct cpuidle_state_usage *, char *);
 241         ssize_t (*store)(struct cpuidle_state *, \
 242                         struct cpuidle_state_usage *, const char *, size_t);
 243 };
 244
 245 #define define_one_state_ro(_name, show) \
 246 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 247
 248 #define define_one_state_rw(_name, show, store) \
 249 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
 250
 251 #define define_show_state_function(_name) \
 252 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 253                          struct cpuidle_state_usage *state_usage, char *buf) \
 254 { \
 255         return sprintf(buf, "%u\n", state->_name);\
 256 }
 257
 258 #define define_show_state_ull_function(_name) \
 259 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 260                                   struct cpuidle_state_usage *state_usage, \
 261                                   char *buf)                            \
 262 { \
 263         return sprintf(buf, "%llu\n", state_usage->_name);\
 264 }
 265
 266 #define define_show_state_str_function(_name) \
 267 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 268                                   struct cpuidle_state_usage *state_usage, \
 269                                   char *buf)                            \
 270 { \
 271         if (state->_name[0] == '\0')\
 272                 return sprintf(buf, "<null>\n");\
 273         return sprintf(buf, "%s\n", state->_name);\
 274 }
 275
 276 #define define_show_state_time_function(_name) \
 277 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 278                                   struct cpuidle_state_usage *state_usage, \
 279                                   char *buf) \
 280 { \
 281         return sprintf(buf, "%llu\n", ktime_to_us(state->_name##_ns)); \
 282 }
 283
 284 define_show_state_time_function(exit_latency)
 285 define_show_state_time_function(target_residency)
 286 define_show_state_function(power_usage)
 287 define_show_state_ull_function(usage)
 288 define_show_state_str_function(name)
 289 define_show_state_str_function(desc)
 290 define_show_state_ull_function(above)
 291 define_show_state_ull_function(below)
 292
 293 static ssize_t show_state_time(struct cpuidle_state *state,
 294                                struct cpuidle_state_usage *state_usage,
 295                                char *buf)
 296 {
 297         return sprintf(buf, "%llu\n", ktime_to_us(state_usage->time_ns));
 298 }
 299
 300 static ssize_t show_state_disable(struct cpuidle_state *state,
 301                                   struct cpuidle_state_usage *state_usage,
 302                                   char *buf)
 303 {
 304         return sprintf(buf, "%llu\n",
 305                        state_usage->disable & CPUIDLE_STATE_DISABLED_BY_USER);
 306 }
 307
 308 static ssize_t store_state_disable(struct cpuidle_state *state,
 309                                    struct cpuidle_state_usage *state_usage,
 310                                    const char *buf, size_t size)
 311 {
 312         unsigned int value;
 313         int err;
 314
 315         if (!capable(CAP_SYS_ADMIN))
 316                 return -EPERM;
 317
 318         err = kstrtouint(buf, 0, &value);
 319         if (err)
 320                 return err;
 321
 322         if (value)
 323                 state_usage->disable |= CPUIDLE_STATE_DISABLED_BY_USER;
 324         else
 325                 state_usage->disable &= ~CPUIDLE_STATE_DISABLED_BY_USER;
 326
 327         return size;
 328 }
 329
 330 define_one_state_ro(name, show_state_name);
 331 define_one_state_ro(desc, show_state_desc);
 332 define_one_state_ro(latency, show_state_exit_latency);
 333 define_one_state_ro(residency, show_state_target_residency);
 334 define_one_state_ro(power, show_state_power_usage);
 335 define_one_state_ro(usage, show_state_usage);
 336 define_one_state_ro(time, show_state_time);
 337 define_one_state_rw(disable, show_state_disable, store_state_disable);
 338 define_one_state_ro(above, show_state_above);
 339 define_one_state_ro(below, show_state_below);
 340
 341 static struct attribute *cpuidle_state_default_attrs[] = {
 342         &attr_name.attr,
 343         &attr_desc.attr,
 344         &attr_latency.attr,
 345         &attr_residency.attr,
 346         &attr_power.attr,
 347         &attr_usage.attr,
 348         &attr_time.attr,
 349         &attr_disable.attr,
 350         &attr_above.attr,
 351         &attr_below.attr,
 352         NULL
 353 };
 354
 355 struct cpuidle_state_kobj {
 356         struct cpuidle_state *state;
 357         struct cpuidle_state_usage *state_usage;
 358         struct completion kobj_unregister;
 359         struct kobject kobj;
 360         struct cpuidle_device *device;
 361 };
 362
 363 #ifdef CONFIG_SUSPEND
 364 #define define_show_state_s2idle_ull_function(_name) \
 365 static ssize_t show_state_s2idle_##_name(struct cpuidle_state *state, \
 366                                          struct cpuidle_state_usage *state_usage, \
 367                                          char *buf)                             \
 368 { \
 369         return sprintf(buf, "%llu\n", state_usage->s2idle_##_name);\
 370 }
 371
 372 define_show_state_s2idle_ull_function(usage);
 373 define_show_state_s2idle_ull_function(time);
 374
 375 #define define_one_state_s2idle_ro(_name, show) \
 376 static struct cpuidle_state_attr attr_s2idle_##_name = \
 377         __ATTR(_name, 0444, show, NULL)
 378
 379 define_one_state_s2idle_ro(usage, show_state_s2idle_usage);
 380 define_one_state_s2idle_ro(time, show_state_s2idle_time);
 381
 382 static struct attribute *cpuidle_state_s2idle_attrs[] = {
 383         &attr_s2idle_usage.attr,
 384         &attr_s2idle_time.attr,
 385         NULL
 386 };
 387
 388 static const struct attribute_group cpuidle_state_s2idle_group = {
 389         .name   = "s2idle",
 390         .attrs  = cpuidle_state_s2idle_attrs,
 391 };
 392
 393 static void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
 394 {
 395         int ret;
 396
 397         if (!kobj->state->enter_s2idle)
 398                 return;
 399
 400         ret = sysfs_create_group(&kobj->kobj, &cpuidle_state_s2idle_group);
 401         if (ret)
 402                 pr_debug("%s: sysfs attribute group not created\n", __func__);
 403 }
 404
 405 static void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
 406 {
 407         if (kobj->state->enter_s2idle)
 408                 sysfs_remove_group(&kobj->kobj, &cpuidle_state_s2idle_group);
 409 }
 410 #else
 411 static inline void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
 412 static inline void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
 413 #endif /* CONFIG_SUSPEND */
 414
 415 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
 416 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
 417 #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
 418 #define kobj_to_device(k) (kobj_to_state_obj(k)->device)
 419 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
 420
 421 static ssize_t cpuidle_state_show(struct kobject *kobj, struct attribute *attr,
 422                                   char * buf)
 423 {
 424         int ret = -EIO;
 425         struct cpuidle_state *state = kobj_to_state(kobj);
 426         struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
 427         struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
 428
 429         if (cattr->show)
 430                 ret = cattr->show(state, state_usage, buf);
 431
 432         return ret;
 433 }
 434
 435 static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr,
 436                                    const char *buf, size_t size)
 437 {
 438         int ret = -EIO;
 439         struct cpuidle_state *state = kobj_to_state(kobj);
 440         struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
 441         struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
 442         struct cpuidle_device *dev = kobj_to_device(kobj);
 443
 444         if (cattr->store)
 445                 ret = cattr->store(state, state_usage, buf, size);
 446
 447         /* reset poll time cache */
 448         dev->poll_limit_ns = 0;
 449
 450         return ret;
 451 }
 452
 453 static const struct sysfs_ops cpuidle_state_sysfs_ops = {
 454         .show = cpuidle_state_show,
 455         .store = cpuidle_state_store,
 456 };
 457
 458 static void cpuidle_state_sysfs_release(struct kobject *kobj)
 459 {
 460         struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
 461
 462         complete(&state_obj->kobj_unregister);
 463 }
 464
 465 static struct kobj_type ktype_state_cpuidle = {
 466         .sysfs_ops = &cpuidle_state_sysfs_ops,
 467         .default_attrs = cpuidle_state_default_attrs,
 468         .release = cpuidle_state_sysfs_release,
 469 };
 470
 471 static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
 472 {
 473         cpuidle_remove_s2idle_attr_group(device->kobjs[i]);
 474         kobject_put(&device->kobjs[i]->kobj);
 475         wait_for_completion(&device->kobjs[i]->kobj_unregister);
 476         kfree(device->kobjs[i]);
 477         device->kobjs[i] = NULL;
 478 }
 479
 480 /**
 481  * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes
 482  * @device: the target device
 483  */
 484 static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
 485 {
 486         int i, ret = -ENOMEM;
 487         struct cpuidle_state_kobj *kobj;
 488         struct cpuidle_device_kobj *kdev = device->kobj_dev;
 489         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
 490
 491         /* state statistics */
 492         for (i = 0; i < drv->state_count; i++) {
 493                 kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
 494                 if (!kobj) {
 495                         ret = -ENOMEM;
 496                         goto error_state;
 497                 }
 498                 kobj->state = &drv->states[i];
 499                 kobj->state_usage = &device->states_usage[i];
 500                 kobj->device = device;
 501                 init_completion(&kobj->kobj_unregister);
 502
 503                 ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
 504                                            &kdev->kobj, "state%d", i);
 505                 if (ret) {
 506                         kfree(kobj);
 507                         goto error_state;
 508                 }
 509                 cpuidle_add_s2idle_attr_group(kobj);
 510                 kobject_uevent(&kobj->kobj, KOBJ_ADD);
 511                 device->kobjs[i] = kobj;
 512         }
 513
 514         return 0;
 515
 516 error_state:
 517         for (i = i - 1; i >= 0; i--)
 518                 cpuidle_free_state_kobj(device, i);
 519         return ret;
 520 }
 521
 522 /**
 523  * cpuidle_remove_driver_sysfs - removes the cpuidle states sysfs attributes
 524  * @device: the target device
 525  */
 526 static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
 527 {
 528         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
 529         int i;
 530
 531         for (i = 0; i < drv->state_count; i++)
 532                 cpuidle_free_state_kobj(device, i);
 533 }
 534
 535 #ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
 536 #define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
 537 #define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
 538
 539 #define define_one_driver_ro(_name, show)                       \
 540         static struct cpuidle_driver_attr attr_driver_##_name = \
 541                 __ATTR(_name, 0444, show, NULL)
 542
 543 struct cpuidle_driver_kobj {
 544         struct cpuidle_driver *drv;
 545         struct completion kobj_unregister;
 546         struct kobject kobj;
 547 };
 548
 549 struct cpuidle_driver_attr {
 550         struct attribute attr;
 551         ssize_t (*show)(struct cpuidle_driver *, char *);
 552         ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
 553 };
 554
 555 static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
 556 {
 557         ssize_t ret;
 558
 559         spin_lock(&cpuidle_driver_lock);
 560         ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
 561         spin_unlock(&cpuidle_driver_lock);
 562
 563         return ret;
 564 }
 565
 566 static void cpuidle_driver_sysfs_release(struct kobject *kobj)
 567 {
 568         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 569         complete(&driver_kobj->kobj_unregister);
 570 }
 571
 572 static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
 573                                    char *buf)
 574 {
 575         int ret = -EIO;
 576         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 577         struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
 578
 579         if (dattr->show)
 580                 ret = dattr->show(driver_kobj->drv, buf);
 581
 582         return ret;
 583 }
 584
 585 static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
 586                                     const char *buf, size_t size)
 587 {
 588         int ret = -EIO;
 589         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 590         struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
 591
 592         if (dattr->store)
 593                 ret = dattr->store(driver_kobj->drv, buf, size);
 594
 595         return ret;
 596 }
 597
 598 define_one_driver_ro(name, show_driver_name);
 599
 600 static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
 601         .show = cpuidle_driver_show,
 602         .store = cpuidle_driver_store,
 603 };
 604
 605 static struct attribute *cpuidle_driver_default_attrs[] = {
 606         &attr_driver_name.attr,
 607         NULL
 608 };
 609
 610 static struct kobj_type ktype_driver_cpuidle = {
 611         .sysfs_ops = &cpuidle_driver_sysfs_ops,
 612         .default_attrs = cpuidle_driver_default_attrs,
 613         .release = cpuidle_driver_sysfs_release,
 614 };
 615
 616 /**
 617  * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
 618  * @device: the target device
 619  */
 620 static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 621 {
 622         struct cpuidle_driver_kobj *kdrv;
 623         struct cpuidle_device_kobj *kdev = dev->kobj_dev;
 624         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
 625         int ret;
 626
 627         kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
 628         if (!kdrv)
 629                 return -ENOMEM;
 630
 631         kdrv->drv = drv;
 632         init_completion(&kdrv->kobj_unregister);
 633
 634         ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
 635                                    &kdev->kobj, "driver");
 636         if (ret) {
 637                 kfree(kdrv);
 638                 return ret;
 639         }
 640
 641         kobject_uevent(&kdrv->kobj, KOBJ_ADD);
 642         dev->kobj_driver = kdrv;
 643
 644         return ret;
 645 }
 646
 647 /**
 648  * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
 649  * @device: the target device
 650  */
 651 static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
 652 {
 653         struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
 654         kobject_put(&kdrv->kobj);
 655         wait_for_completion(&kdrv->kobj_unregister);
 656         kfree(kdrv);
 657 }
 658 #else
 659 static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 660 {
 661         return 0;
 662 }
 663
 664 static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
 665 {
 666         ;
 667 }
 668 #endif
 669
 670 /**
 671  * cpuidle_add_device_sysfs - adds device specific sysfs attributes
 672  * @device: the target device
 673  */
 674 int cpuidle_add_device_sysfs(struct cpuidle_device *device)
 675 {
 676         int ret;
 677
 678         ret = cpuidle_add_state_sysfs(device);
 679         if (ret)
 680                 return ret;
 681
 682         ret = cpuidle_add_driver_sysfs(device);
 683         if (ret)
 684                 cpuidle_remove_state_sysfs(device);
 685         return ret;
 686 }
 687
 688 /**
 689  * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
 690  * @device : the target device
 691  */
 692 void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
 693 {
 694         cpuidle_remove_driver_sysfs(device);
 695         cpuidle_remove_state_sysfs(device);
 696 }
 697
 698 /**
 699  * cpuidle_add_sysfs - creates a sysfs instance for the target device
 700  * @dev: the target device
 701  */
 702 int cpuidle_add_sysfs(struct cpuidle_device *dev)
 703 {
 704         struct cpuidle_device_kobj *kdev;
 705         struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
 706         int error;
 707
 708         /*
 709          * Return if cpu_device is not setup for this CPU.
 710          *
 711          * This could happen if the arch did not set up cpu_device
 712          * since this CPU is not in cpu_present mask and the
 713          * driver did not send a correct CPU mask during registration.
 714          * Without this check we would end up passing bogus
 715          * value for &cpu_dev->kobj in kobject_init_and_add()
 716          */
 717         if (!cpu_dev)
 718                 return -ENODEV;
 719
 720         kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
 721         if (!kdev)
 722                 return -ENOMEM;
 723         kdev->dev = dev;
 724         dev->kobj_dev = kdev;
 725
 726         init_completion(&kdev->kobj_unregister);
 727
 728         error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
 729                                    "cpuidle");
 730         if (error) {
 731                 kfree(kdev);
 732                 return error;
 733         }
 734
 735         kobject_uevent(&kdev->kobj, KOBJ_ADD);
 736
 737         return 0;
 738 }
 739
 740 /**
 741  * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
 742  * @dev: the target device
 743  */
 744 void cpuidle_remove_sysfs(struct cpuidle_device *dev)
 745 {
 746         struct cpuidle_device_kobj *kdev = dev->kobj_dev;
 747
 748         kobject_put(&kdev->kobj);
 749         wait_for_completion(&kdev->kobj_unregister);
 750         kfree(kdev);
 751 }