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 } 733