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_store_state_ull_function(_name) \ 259 static ssize_t store_state_##_name(struct cpuidle_state *state, \ 260 struct cpuidle_state_usage *state_usage, \ 261 const char *buf, size_t size) \ 262 { \ 263 unsigned long long value; \ 264 int err; \ 265 if (!capable(CAP_SYS_ADMIN)) \ 266 return -EPERM; \ 267 err = kstrtoull(buf, 0, &value); \ 268 if (err) \ 269 return err; \ 270 if (value) \ 271 state_usage->_name = 1; \ 272 else \ 273 state_usage->_name = 0; \ 274 return size; \ 275 } 276 277 #define define_show_state_ull_function(_name) \ 278 static ssize_t show_state_##_name(struct cpuidle_state *state, \ 279 struct cpuidle_state_usage *state_usage, \ 280 char *buf) \ 281 { \ 282 return sprintf(buf, "%llu\n", state_usage->_name);\ 283 } 284 285 #define define_show_state_str_function(_name) \ 286 static ssize_t show_state_##_name(struct cpuidle_state *state, \ 287 struct cpuidle_state_usage *state_usage, \ 288 char *buf) \ 289 { \ 290 if (state->_name[0] == '\0')\ 291 return sprintf(buf, "<null>\n");\ 292 return sprintf(buf, "%s\n", state->_name);\ 293 } 294 295 define_show_state_function(exit_latency) 296 define_show_state_function(target_residency) 297 define_show_state_function(power_usage) 298 define_show_state_ull_function(usage) 299 define_show_state_ull_function(time) 300 define_show_state_str_function(name) 301 define_show_state_str_function(desc) 302 define_show_state_ull_function(disable) 303 define_store_state_ull_function(disable) 304 305 define_one_state_ro(name, show_state_name); 306 define_one_state_ro(desc, show_state_desc); 307 define_one_state_ro(latency, show_state_exit_latency); 308 define_one_state_ro(residency, show_state_target_residency); 309 define_one_state_ro(power, show_state_power_usage); 310 define_one_state_ro(usage, show_state_usage); 311 define_one_state_ro(time, show_state_time); 312 define_one_state_rw(disable, show_state_disable, store_state_disable); 313 314 static struct attribute *cpuidle_state_default_attrs[] = { 315 &attr_name.attr, 316 &attr_desc.attr, 317 &attr_latency.attr, 318 &attr_residency.attr, 319 &attr_power.attr, 320 &attr_usage.attr, 321 &attr_time.attr, 322 &attr_disable.attr, 323 NULL 324 }; 325 326 struct cpuidle_state_kobj { 327 struct cpuidle_state *state; 328 struct cpuidle_state_usage *state_usage; 329 struct completion kobj_unregister; 330 struct kobject kobj; 331 }; 332 333 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj) 334 #define kobj_to_state(k) (kobj_to_state_obj(k)->state) 335 #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage) 336 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr) 337 338 static ssize_t cpuidle_state_show(struct kobject *kobj, struct attribute *attr, 339 char * buf) 340 { 341 int ret = -EIO; 342 struct cpuidle_state *state = kobj_to_state(kobj); 343 struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj); 344 struct cpuidle_state_attr * cattr = attr_to_stateattr(attr); 345 346 if (cattr->show) 347 ret = cattr->show(state, state_usage, buf); 348 349 return ret; 350 } 351 352 static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr, 353 const char *buf, size_t size) 354 { 355 int ret = -EIO; 356 struct cpuidle_state *state = kobj_to_state(kobj); 357 struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj); 358 struct cpuidle_state_attr *cattr = attr_to_stateattr(attr); 359 360 if (cattr->store) 361 ret = cattr->store(state, state_usage, buf, size); 362 363 return ret; 364 } 365 366 static const struct sysfs_ops cpuidle_state_sysfs_ops = { 367 .show = cpuidle_state_show, 368 .store = cpuidle_state_store, 369 }; 370 371 static void cpuidle_state_sysfs_release(struct kobject *kobj) 372 { 373 struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj); 374 375 complete(&state_obj->kobj_unregister); 376 } 377 378 static struct kobj_type ktype_state_cpuidle = { 379 .sysfs_ops = &cpuidle_state_sysfs_ops, 380 .default_attrs = cpuidle_state_default_attrs, 381 .release = cpuidle_state_sysfs_release, 382 }; 383 384 static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i) 385 { 386 kobject_put(&device->kobjs[i]->kobj); 387 wait_for_completion(&device->kobjs[i]->kobj_unregister); 388 kfree(device->kobjs[i]); 389 device->kobjs[i] = NULL; 390 } 391 392 /** 393 * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes 394 * @device: the target device 395 */ 396 static int cpuidle_add_state_sysfs(struct cpuidle_device *device) 397 { 398 int i, ret = -ENOMEM; 399 struct cpuidle_state_kobj *kobj; 400 struct cpuidle_device_kobj *kdev = device->kobj_dev; 401 struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device); 402 403 /* state statistics */ 404 for (i = 0; i < device->state_count; i++) { 405 kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL); 406 if (!kobj) 407 goto error_state; 408 kobj->state = &drv->states[i]; 409 kobj->state_usage = &device->states_usage[i]; 410 init_completion(&kobj->kobj_unregister); 411 412 ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle, 413 &kdev->kobj, "state%d", i); 414 if (ret) { 415 kfree(kobj); 416 goto error_state; 417 } 418 kobject_uevent(&kobj->kobj, KOBJ_ADD); 419 device->kobjs[i] = kobj; 420 } 421 422 return 0; 423 424 error_state: 425 for (i = i - 1; i >= 0; i--) 426 cpuidle_free_state_kobj(device, i); 427 return ret; 428 } 429 430 /** 431 * cpuidle_remove_driver_sysfs - removes the cpuidle states sysfs attributes 432 * @device: the target device 433 */ 434 static void cpuidle_remove_state_sysfs(struct cpuidle_device *device) 435 { 436 int i; 437 438 for (i = 0; i < device->state_count; i++) 439 cpuidle_free_state_kobj(device, i); 440 } 441 442 #ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS 443 #define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj) 444 #define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr) 445 446 #define define_one_driver_ro(_name, show) \ 447 static struct cpuidle_driver_attr attr_driver_##_name = \ 448 __ATTR(_name, 0444, show, NULL) 449 450 struct cpuidle_driver_kobj { 451 struct cpuidle_driver *drv; 452 struct completion kobj_unregister; 453 struct kobject kobj; 454 }; 455 456 struct cpuidle_driver_attr { 457 struct attribute attr; 458 ssize_t (*show)(struct cpuidle_driver *, char *); 459 ssize_t (*store)(struct cpuidle_driver *, const char *, size_t); 460 }; 461 462 static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf) 463 { 464 ssize_t ret; 465 466 spin_lock(&cpuidle_driver_lock); 467 ret = sprintf(buf, "%s\n", drv ? drv->name : "none"); 468 spin_unlock(&cpuidle_driver_lock); 469 470 return ret; 471 } 472 473 static void cpuidle_driver_sysfs_release(struct kobject *kobj) 474 { 475 struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj); 476 complete(&driver_kobj->kobj_unregister); 477 } 478 479 static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr, 480 char *buf) 481 { 482 int ret = -EIO; 483 struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj); 484 struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr); 485 486 if (dattr->show) 487 ret = dattr->show(driver_kobj->drv, buf); 488 489 return ret; 490 } 491 492 static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr, 493 const char *buf, size_t size) 494 { 495 int ret = -EIO; 496 struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj); 497 struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr); 498 499 if (dattr->store) 500 ret = dattr->store(driver_kobj->drv, buf, size); 501 502 return ret; 503 } 504 505 define_one_driver_ro(name, show_driver_name); 506 507 static const struct sysfs_ops cpuidle_driver_sysfs_ops = { 508 .show = cpuidle_driver_show, 509 .store = cpuidle_driver_store, 510 }; 511 512 static struct attribute *cpuidle_driver_default_attrs[] = { 513 &attr_driver_name.attr, 514 NULL 515 }; 516 517 static struct kobj_type ktype_driver_cpuidle = { 518 .sysfs_ops = &cpuidle_driver_sysfs_ops, 519 .default_attrs = cpuidle_driver_default_attrs, 520 .release = cpuidle_driver_sysfs_release, 521 }; 522 523 /** 524 * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute 525 * @device: the target device 526 */ 527 static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev) 528 { 529 struct cpuidle_driver_kobj *kdrv; 530 struct cpuidle_device_kobj *kdev = dev->kobj_dev; 531 struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); 532 int ret; 533 534 kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL); 535 if (!kdrv) 536 return -ENOMEM; 537 538 kdrv->drv = drv; 539 init_completion(&kdrv->kobj_unregister); 540 541 ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle, 542 &kdev->kobj, "driver"); 543 if (ret) { 544 kfree(kdrv); 545 return ret; 546 } 547 548 kobject_uevent(&kdrv->kobj, KOBJ_ADD); 549 dev->kobj_driver = kdrv; 550 551 return ret; 552 } 553 554 /** 555 * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute 556 * @device: the target device 557 */ 558 static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev) 559 { 560 struct cpuidle_driver_kobj *kdrv = dev->kobj_driver; 561 kobject_put(&kdrv->kobj); 562 wait_for_completion(&kdrv->kobj_unregister); 563 kfree(kdrv); 564 } 565 #else 566 static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev) 567 { 568 return 0; 569 } 570 571 static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev) 572 { 573 ; 574 } 575 #endif 576 577 /** 578 * cpuidle_add_device_sysfs - adds device specific sysfs attributes 579 * @device: the target device 580 */ 581 int cpuidle_add_device_sysfs(struct cpuidle_device *device) 582 { 583 int ret; 584 585 ret = cpuidle_add_state_sysfs(device); 586 if (ret) 587 return ret; 588 589 ret = cpuidle_add_driver_sysfs(device); 590 if (ret) 591 cpuidle_remove_state_sysfs(device); 592 return ret; 593 } 594 595 /** 596 * cpuidle_remove_device_sysfs : removes device specific sysfs attributes 597 * @device : the target device 598 */ 599 void cpuidle_remove_device_sysfs(struct cpuidle_device *device) 600 { 601 cpuidle_remove_driver_sysfs(device); 602 cpuidle_remove_state_sysfs(device); 603 } 604 605 /** 606 * cpuidle_add_sysfs - creates a sysfs instance for the target device 607 * @dev: the target device 608 */ 609 int cpuidle_add_sysfs(struct cpuidle_device *dev) 610 { 611 struct cpuidle_device_kobj *kdev; 612 struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu); 613 int error; 614 615 kdev = kzalloc(sizeof(*kdev), GFP_KERNEL); 616 if (!kdev) 617 return -ENOMEM; 618 kdev->dev = dev; 619 dev->kobj_dev = kdev; 620 621 init_completion(&kdev->kobj_unregister); 622 623 error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj, 624 "cpuidle"); 625 if (error) { 626 kfree(kdev); 627 return error; 628 } 629 630 kobject_uevent(&kdev->kobj, KOBJ_ADD); 631 632 return 0; 633 } 634 635 /** 636 * cpuidle_remove_sysfs - deletes a sysfs instance on the target device 637 * @dev: the target device 638 */ 639 void cpuidle_remove_sysfs(struct cpuidle_device *dev) 640 { 641 struct cpuidle_device_kobj *kdev = dev->kobj_dev; 642 643 kobject_put(&kdev->kobj); 644 wait_for_completion(&kdev->kobj_unregister); 645 kfree(kdev); 646 } 647