drivers/cpuidle/sysfs.c

   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 *cpuidle_driver = cpuidle_get_driver();
  56
  57         spin_lock(&cpuidle_driver_lock);
  58         if (cpuidle_driver)
  59                 ret = sprintf(buf, "%s\n", cpuidle_driver->name);
  60         else
  61                 ret = sprintf(buf, "none\n");
  62         spin_unlock(&cpuidle_driver_lock);
  63
  64         return ret;
  65 }
  66
  67 static ssize_t show_current_governor(struct device *dev,
  68                                      struct device_attribute *attr,
  69                                      char *buf)
  70 {
  71         ssize_t ret;
  72
  73         mutex_lock(&cpuidle_lock);
  74         if (cpuidle_curr_governor)
  75                 ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
  76         else
  77                 ret = sprintf(buf, "none\n");
  78         mutex_unlock(&cpuidle_lock);
  79
  80         return ret;
  81 }
  82
  83 static ssize_t store_current_governor(struct device *dev,
  84                                       struct device_attribute *attr,
  85                                       const char *buf, size_t count)
  86 {
  87         char gov_name[CPUIDLE_NAME_LEN];
  88         int ret = -EINVAL;
  89         size_t len = count;
  90         struct cpuidle_governor *gov;
  91
  92         if (!len || len >= sizeof(gov_name))
  93                 return -EINVAL;
  94
  95         memcpy(gov_name, buf, len);
  96         gov_name[len] = '\0';
  97         if (gov_name[len - 1] == '\n')
  98                 gov_name[--len] = '\0';
  99
 100         mutex_lock(&cpuidle_lock);
 101
 102         list_for_each_entry(gov, &cpuidle_governors, governor_list) {
 103                 if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
 104                         ret = cpuidle_switch_governor(gov);
 105                         break;
 106                 }
 107         }
 108
 109         mutex_unlock(&cpuidle_lock);
 110
 111         if (ret)
 112                 return ret;
 113         else
 114                 return count;
 115 }
 116
 117 static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
 118 static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
 119
 120 static struct attribute *cpuidle_default_attrs[] = {
 121         &dev_attr_current_driver.attr,
 122         &dev_attr_current_governor_ro.attr,
 123         NULL
 124 };
 125
 126 static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
 127 static DEVICE_ATTR(current_governor, 0644, show_current_governor,
 128                    store_current_governor);
 129
 130 static struct attribute *cpuidle_switch_attrs[] = {
 131         &dev_attr_available_governors.attr,
 132         &dev_attr_current_driver.attr,
 133         &dev_attr_current_governor.attr,
 134         NULL
 135 };
 136
 137 static struct attribute_group cpuidle_attr_group = {
 138         .attrs = cpuidle_default_attrs,
 139         .name = "cpuidle",
 140 };
 141
 142 /**
 143  * cpuidle_add_interface - add CPU global sysfs attributes
 144  */
 145 int cpuidle_add_interface(struct device *dev)
 146 {
 147         if (sysfs_switch)
 148                 cpuidle_attr_group.attrs = cpuidle_switch_attrs;
 149
 150         return sysfs_create_group(&dev->kobj, &cpuidle_attr_group);
 151 }
 152
 153 /**
 154  * cpuidle_remove_interface - remove CPU global sysfs attributes
 155  */
 156 void cpuidle_remove_interface(struct device *dev)
 157 {
 158         sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
 159 }
 160
 161 struct cpuidle_attr {
 162         struct attribute attr;
 163         ssize_t (*show)(struct cpuidle_device *, char *);
 164         ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
 165 };
 166
 167 #define define_one_ro(_name, show) \
 168         static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 169 #define define_one_rw(_name, show, store) \
 170         static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
 171
 172 #define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
 173
 174 struct cpuidle_device_kobj {
 175         struct cpuidle_device *dev;
 176         struct completion kobj_unregister;
 177         struct kobject kobj;
 178 };
 179
 180 static inline struct cpuidle_device *to_cpuidle_device(struct kobject *kobj)
 181 {
 182         struct cpuidle_device_kobj *kdev =
 183                 container_of(kobj, struct cpuidle_device_kobj, kobj);
 184
 185         return kdev->dev;
 186 }
 187
 188 static ssize_t cpuidle_show(struct kobject *kobj, struct attribute *attr,
 189                             char *buf)
 190 {
 191         int ret = -EIO;
 192         struct cpuidle_device *dev = to_cpuidle_device(kobj);
 193         struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
 194
 195         if (cattr->show) {
 196                 mutex_lock(&cpuidle_lock);
 197                 ret = cattr->show(dev, buf);
 198                 mutex_unlock(&cpuidle_lock);
 199         }
 200         return ret;
 201 }
 202
 203 static ssize_t cpuidle_store(struct kobject *kobj, struct attribute *attr,
 204                              const char *buf, size_t count)
 205 {
 206         int ret = -EIO;
 207         struct cpuidle_device *dev = to_cpuidle_device(kobj);
 208         struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
 209
 210         if (cattr->store) {
 211                 mutex_lock(&cpuidle_lock);
 212                 ret = cattr->store(dev, buf, count);
 213                 mutex_unlock(&cpuidle_lock);
 214         }
 215         return ret;
 216 }
 217
 218 static const struct sysfs_ops cpuidle_sysfs_ops = {
 219         .show = cpuidle_show,
 220         .store = cpuidle_store,
 221 };
 222
 223 static void cpuidle_sysfs_release(struct kobject *kobj)
 224 {
 225         struct cpuidle_device_kobj *kdev =
 226                 container_of(kobj, struct cpuidle_device_kobj, kobj);
 227
 228         complete(&kdev->kobj_unregister);
 229 }
 230
 231 static struct kobj_type ktype_cpuidle = {
 232         .sysfs_ops = &cpuidle_sysfs_ops,
 233         .release = cpuidle_sysfs_release,
 234 };
 235
 236 struct cpuidle_state_attr {
 237         struct attribute attr;
 238         ssize_t (*show)(struct cpuidle_state *, \
 239                                         struct cpuidle_state_usage *, char *);
 240         ssize_t (*store)(struct cpuidle_state *, \
 241                         struct cpuidle_state_usage *, const char *, size_t);
 242 };
 243
 244 #define define_one_state_ro(_name, show) \
 245 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 246
 247 #define define_one_state_rw(_name, show, store) \
 248 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
 249
 250 #define define_show_state_function(_name) \
 251 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 252                          struct cpuidle_state_usage *state_usage, char *buf) \
 253 { \
 254         return sprintf(buf, "%u\n", state->_name);\
 255 }
 256
 257 #define define_store_state_ull_function(_name) \
 258 static ssize_t store_state_##_name(struct cpuidle_state *state, \
 259                                    struct cpuidle_state_usage *state_usage, \
 260                                    const char *buf, size_t size)        \
 261 { \
 262         unsigned long long value; \
 263         int err; \
 264         if (!capable(CAP_SYS_ADMIN)) \
 265                 return -EPERM; \
 266         err = kstrtoull(buf, 0, &value); \
 267         if (err) \
 268                 return err; \
 269         if (value) \
 270                 state_usage->_name = 1; \
 271         else \
 272                 state_usage->_name = 0; \
 273         return size; \
 274 }
 275
 276 #define define_show_state_ull_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", state_usage->_name);\
 282 }
 283
 284 #define define_show_state_str_function(_name) \
 285 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 286                                   struct cpuidle_state_usage *state_usage, \
 287                                   char *buf)                            \
 288 { \
 289         if (state->_name[0] == '\0')\
 290                 return sprintf(buf, "<null>\n");\
 291         return sprintf(buf, "%s\n", state->_name);\
 292 }
 293
 294 define_show_state_function(exit_latency)
 295 define_show_state_function(power_usage)
 296 define_show_state_ull_function(usage)
 297 define_show_state_ull_function(time)
 298 define_show_state_str_function(name)
 299 define_show_state_str_function(desc)
 300 define_show_state_ull_function(disable)
 301 define_store_state_ull_function(disable)
 302
 303 define_one_state_ro(name, show_state_name);
 304 define_one_state_ro(desc, show_state_desc);
 305 define_one_state_ro(latency, show_state_exit_latency);
 306 define_one_state_ro(power, show_state_power_usage);
 307 define_one_state_ro(usage, show_state_usage);
 308 define_one_state_ro(time, show_state_time);
 309 define_one_state_rw(disable, show_state_disable, store_state_disable);
 310
 311 static struct attribute *cpuidle_state_default_attrs[] = {
 312         &attr_name.attr,
 313         &attr_desc.attr,
 314         &attr_latency.attr,
 315         &attr_power.attr,
 316         &attr_usage.attr,
 317         &attr_time.attr,
 318         &attr_disable.attr,
 319         NULL
 320 };
 321
 322 struct cpuidle_state_kobj {
 323         struct cpuidle_state *state;
 324         struct cpuidle_state_usage *state_usage;
 325         struct completion kobj_unregister;
 326         struct kobject kobj;
 327 };
 328
 329 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
 330 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
 331 #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
 332 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
 333
 334 static ssize_t cpuidle_state_show(struct kobject *kobj, struct attribute *attr,
 335                                   char * buf)
 336 {
 337         int ret = -EIO;
 338         struct cpuidle_state *state = kobj_to_state(kobj);
 339         struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
 340         struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
 341
 342         if (cattr->show)
 343                 ret = cattr->show(state, state_usage, buf);
 344
 345         return ret;
 346 }
 347
 348 static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr,
 349                                    const char *buf, size_t size)
 350 {
 351         int ret = -EIO;
 352         struct cpuidle_state *state = kobj_to_state(kobj);
 353         struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
 354         struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
 355
 356         if (cattr->store)
 357                 ret = cattr->store(state, state_usage, buf, size);
 358
 359         return ret;
 360 }
 361
 362 static const struct sysfs_ops cpuidle_state_sysfs_ops = {
 363         .show = cpuidle_state_show,
 364         .store = cpuidle_state_store,
 365 };
 366
 367 static void cpuidle_state_sysfs_release(struct kobject *kobj)
 368 {
 369         struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
 370
 371         complete(&state_obj->kobj_unregister);
 372 }
 373
 374 static struct kobj_type ktype_state_cpuidle = {
 375         .sysfs_ops = &cpuidle_state_sysfs_ops,
 376         .default_attrs = cpuidle_state_default_attrs,
 377         .release = cpuidle_state_sysfs_release,
 378 };
 379
 380 static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
 381 {
 382         kobject_put(&device->kobjs[i]->kobj);
 383         wait_for_completion(&device->kobjs[i]->kobj_unregister);
 384         kfree(device->kobjs[i]);
 385         device->kobjs[i] = NULL;
 386 }
 387
 388 /**
 389  * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes
 390  * @device: the target device
 391  */
 392 static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
 393 {
 394         int i, ret = -ENOMEM;
 395         struct cpuidle_state_kobj *kobj;
 396         struct cpuidle_device_kobj *kdev = device->kobj_dev;
 397         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
 398
 399         /* state statistics */
 400         for (i = 0; i < device->state_count; i++) {
 401                 kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
 402                 if (!kobj)
 403                         goto error_state;
 404                 kobj->state = &drv->states[i];
 405                 kobj->state_usage = &device->states_usage[i];
 406                 init_completion(&kobj->kobj_unregister);
 407
 408                 ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
 409                                            &kdev->kobj, "state%d", i);
 410                 if (ret) {
 411                         kfree(kobj);
 412                         goto error_state;
 413                 }
 414                 kobject_uevent(&kobj->kobj, KOBJ_ADD);
 415                 device->kobjs[i] = kobj;
 416         }
 417
 418         return 0;
 419
 420 error_state:
 421         for (i = i - 1; i >= 0; i--)
 422                 cpuidle_free_state_kobj(device, i);
 423         return ret;
 424 }
 425
 426 /**
 427  * cpuidle_remove_driver_sysfs - removes the cpuidle states sysfs attributes
 428  * @device: the target device
 429  */
 430 static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
 431 {
 432         int i;
 433
 434         for (i = 0; i < device->state_count; i++)
 435                 cpuidle_free_state_kobj(device, i);
 436 }
 437
 438 #ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
 439 #define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
 440 #define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
 441
 442 #define define_one_driver_ro(_name, show)                       \
 443         static struct cpuidle_driver_attr attr_driver_##_name = \
 444                 __ATTR(_name, 0644, show, NULL)
 445
 446 struct cpuidle_driver_kobj {
 447         struct cpuidle_driver *drv;
 448         struct completion kobj_unregister;
 449         struct kobject kobj;
 450 };
 451
 452 struct cpuidle_driver_attr {
 453         struct attribute attr;
 454         ssize_t (*show)(struct cpuidle_driver *, char *);
 455         ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
 456 };
 457
 458 static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
 459 {
 460         ssize_t ret;
 461
 462         spin_lock(&cpuidle_driver_lock);
 463         ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
 464         spin_unlock(&cpuidle_driver_lock);
 465
 466         return ret;
 467 }
 468
 469 static void cpuidle_driver_sysfs_release(struct kobject *kobj)
 470 {
 471         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 472         complete(&driver_kobj->kobj_unregister);
 473 }
 474
 475 static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
 476                                    char *buf)
 477 {
 478         int ret = -EIO;
 479         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 480         struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
 481
 482         if (dattr->show)
 483                 ret = dattr->show(driver_kobj->drv, buf);
 484
 485         return ret;
 486 }
 487
 488 static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
 489                                     const char *buf, size_t size)
 490 {
 491         int ret = -EIO;
 492         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
 493         struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
 494
 495         if (dattr->store)
 496                 ret = dattr->store(driver_kobj->drv, buf, size);
 497
 498         return ret;
 499 }
 500
 501 define_one_driver_ro(name, show_driver_name);
 502
 503 static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
 504         .show = cpuidle_driver_show,
 505         .store = cpuidle_driver_store,
 506 };
 507
 508 static struct attribute *cpuidle_driver_default_attrs[] = {
 509         &attr_driver_name.attr,
 510         NULL
 511 };
 512
 513 static struct kobj_type ktype_driver_cpuidle = {
 514         .sysfs_ops = &cpuidle_driver_sysfs_ops,
 515         .default_attrs = cpuidle_driver_default_attrs,
 516         .release = cpuidle_driver_sysfs_release,
 517 };
 518
 519 /**
 520  * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
 521  * @device: the target device
 522  */
 523 static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 524 {
 525         struct cpuidle_driver_kobj *kdrv;
 526         struct cpuidle_device_kobj *kdev = dev->kobj_dev;
 527         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
 528         int ret;
 529
 530         kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
 531         if (!kdrv)
 532                 return -ENOMEM;
 533
 534         kdrv->drv = drv;
 535         init_completion(&kdrv->kobj_unregister);
 536
 537         ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
 538                                    &kdev->kobj, "driver");
 539         if (ret) {
 540                 kfree(kdrv);
 541                 return ret;
 542         }
 543
 544         kobject_uevent(&kdrv->kobj, KOBJ_ADD);
 545         dev->kobj_driver = kdrv;
 546
 547         return ret;
 548 }
 549
 550 /**
 551  * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
 552  * @device: the target device
 553  */
 554 static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
 555 {
 556         struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
 557         kobject_put(&kdrv->kobj);
 558         wait_for_completion(&kdrv->kobj_unregister);
 559         kfree(kdrv);
 560 }
 561 #else
 562 static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 563 {
 564         return 0;
 565 }
 566
 567 static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
 568 {
 569         ;
 570 }
 571 #endif
 572
 573 /**
 574  * cpuidle_add_device_sysfs - adds device specific sysfs attributes
 575  * @device: the target device
 576  */
 577 int cpuidle_add_device_sysfs(struct cpuidle_device *device)
 578 {
 579         int ret;
 580
 581         ret = cpuidle_add_state_sysfs(device);
 582         if (ret)
 583                 return ret;
 584
 585         ret = cpuidle_add_driver_sysfs(device);
 586         if (ret)
 587                 cpuidle_remove_state_sysfs(device);
 588         return ret;
 589 }
 590
 591 /**
 592  * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
 593  * @device : the target device
 594  */
 595 void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
 596 {
 597         cpuidle_remove_driver_sysfs(device);
 598         cpuidle_remove_state_sysfs(device);
 599 }
 600
 601 /**
 602  * cpuidle_add_sysfs - creates a sysfs instance for the target device
 603  * @dev: the target device
 604  */
 605 int cpuidle_add_sysfs(struct cpuidle_device *dev)
 606 {
 607         struct cpuidle_device_kobj *kdev;
 608         struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
 609         int error;
 610
 611         kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
 612         if (!kdev)
 613                 return -ENOMEM;
 614         kdev->dev = dev;
 615         dev->kobj_dev = kdev;
 616
 617         init_completion(&kdev->kobj_unregister);
 618
 619         error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
 620                                    "cpuidle");
 621         if (error) {
 622                 kfree(kdev);
 623                 return error;
 624         }
 625
 626         kobject_uevent(&kdev->kobj, KOBJ_ADD);
 627
 628         return 0;
 629 }
 630
 631 /**
 632  * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
 633  * @dev: the target device
 634  */
 635 void cpuidle_remove_sysfs(struct cpuidle_device *dev)
 636 {
 637         struct cpuidle_device_kobj *kdev = dev->kobj_dev;
 638
 639         kobject_put(&kdev->kobj);
 640         wait_for_completion(&kdev->kobj_unregister);
 641         kfree(kdev);
 642 }