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 */ 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 } 752