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 } 764