linux/drivers/cpuidle/sysfs.c
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   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
  21static unsigned int sysfs_switch;
  22static 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
  29static 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
  44out:
  45        i+= sprintf(&buf[i], "\n");
  46        mutex_unlock(&cpuidle_lock);
  47        return i;
  48}
  49
  50static 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
  67static 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
  83static 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
 117static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
 118static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
 119
 120static struct attribute *cpuidle_default_attrs[] = {
 121        &dev_attr_current_driver.attr,
 122        &dev_attr_current_governor_ro.attr,
 123        NULL
 124};
 125
 126static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
 127static DEVICE_ATTR(current_governor, 0644, show_current_governor,
 128                   store_current_governor);
 129
 130static 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
 137static 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 */
 145int 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 */
 156void cpuidle_remove_interface(struct device *dev)
 157{
 158        sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
 159}
 160
 161struct 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
 174struct cpuidle_device_kobj {
 175        struct cpuidle_device *dev;
 176        struct completion kobj_unregister;
 177        struct kobject kobj;
 178};
 179
 180static 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
 188static 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
 203static 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
 218static const struct sysfs_ops cpuidle_sysfs_ops = {
 219        .show = cpuidle_show,
 220        .store = cpuidle_store,
 221};
 222
 223static 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
 231static struct kobj_type ktype_cpuidle = {
 232        .sysfs_ops = &cpuidle_sysfs_ops,
 233        .release = cpuidle_sysfs_release,
 234};
 235
 236struct 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) \
 245static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 246
 247#define define_one_state_rw(_name, show, store) \
 248static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
 249
 250#define define_show_state_function(_name) \
 251static 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) \
 258static 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) \
 277static 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) \
 285static 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
 294define_show_state_function(exit_latency)
 295define_show_state_function(power_usage)
 296define_show_state_ull_function(usage)
 297define_show_state_ull_function(time)
 298define_show_state_str_function(name)
 299define_show_state_str_function(desc)
 300define_show_state_ull_function(disable)
 301define_store_state_ull_function(disable)
 302
 303define_one_state_ro(name, show_state_name);
 304define_one_state_ro(desc, show_state_desc);
 305define_one_state_ro(latency, show_state_exit_latency);
 306define_one_state_ro(power, show_state_power_usage);
 307define_one_state_ro(usage, show_state_usage);
 308define_one_state_ro(time, show_state_time);
 309define_one_state_rw(disable, show_state_disable, store_state_disable);
 310
 311static 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
 322struct 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
 334static 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
 348static 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
 362static const struct sysfs_ops cpuidle_state_sysfs_ops = {
 363        .show = cpuidle_state_show,
 364        .store = cpuidle_state_store,
 365};
 366
 367static 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
 374static 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
 380static 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 */
 392static 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
 420error_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 */
 430static 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
 446struct cpuidle_driver_kobj {
 447        struct cpuidle_driver *drv;
 448        struct completion kobj_unregister;
 449        struct kobject kobj;
 450};
 451
 452struct 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
 458static 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
 469static 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
 475static 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
 488static 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
 501define_one_driver_ro(name, show_driver_name);
 502
 503static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
 504        .show = cpuidle_driver_show,
 505        .store = cpuidle_driver_store,
 506};
 507
 508static struct attribute *cpuidle_driver_default_attrs[] = {
 509        &attr_driver_name.attr,
 510        NULL
 511};
 512
 513static 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 */
 523static 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 */
 554static 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
 562static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 563{
 564        return 0;
 565}
 566
 567static 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 */
 577int 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 */
 595void 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 */
 605int 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 */
 635void 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}
 643
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