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/capability.h>
  15
  16 #include "cpuidle.h"
  17
  18 static unsigned int sysfs_switch;
  19 static int __init cpuidle_sysfs_setup(char *unused)
  20 {
  21         sysfs_switch = 1;
  22         return 1;
  23 }
  24 __setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);
  25
  26 static ssize_t show_available_governors(struct device *dev,
  27                                         struct device_attribute *attr,
  28                                         char *buf)
  29 {
  30         ssize_t i = 0;
  31         struct cpuidle_governor *tmp;
  32
  33         mutex_lock(&cpuidle_lock);
  34         list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
  35                 if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) - CPUIDLE_NAME_LEN - 2))
  36                         goto out;
  37                 i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
  38         }
  39
  40 out:
  41         i+= sprintf(&buf[i], "\n");
  42         mutex_unlock(&cpuidle_lock);
  43         return i;
  44 }
  45
  46 static ssize_t show_current_driver(struct device *dev,
  47                                    struct device_attribute *attr,
  48                                    char *buf)
  49 {
  50         ssize_t ret;
  51         struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
  52
  53         spin_lock(&cpuidle_driver_lock);
  54         if (cpuidle_driver)
  55                 ret = sprintf(buf, "%s\n", cpuidle_driver->name);
  56         else
  57                 ret = sprintf(buf, "none\n");
  58         spin_unlock(&cpuidle_driver_lock);
  59
  60         return ret;
  61 }
  62
  63 static ssize_t show_current_governor(struct device *dev,
  64                                      struct device_attribute *attr,
  65                                      char *buf)
  66 {
  67         ssize_t ret;
  68
  69         mutex_lock(&cpuidle_lock);
  70         if (cpuidle_curr_governor)
  71                 ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
  72         else
  73                 ret = sprintf(buf, "none\n");
  74         mutex_unlock(&cpuidle_lock);
  75
  76         return ret;
  77 }
  78
  79 static ssize_t store_current_governor(struct device *dev,
  80                                       struct device_attribute *attr,
  81                                       const char *buf, size_t count)
  82 {
  83         char gov_name[CPUIDLE_NAME_LEN];
  84         int ret = -EINVAL;
  85         size_t len = count;
  86         struct cpuidle_governor *gov;
  87
  88         if (!len || len >= sizeof(gov_name))
  89                 return -EINVAL;
  90
  91         memcpy(gov_name, buf, len);
  92         gov_name[len] = '\0';
  93         if (gov_name[len - 1] == '\n')
  94                 gov_name[--len] = '\0';
  95
  96         mutex_lock(&cpuidle_lock);
  97
  98         list_for_each_entry(gov, &cpuidle_governors, governor_list) {
  99                 if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
 100                         ret = cpuidle_switch_governor(gov);
 101                         break;
 102                 }
 103         }
 104
 105         mutex_unlock(&cpuidle_lock);
 106
 107         if (ret)
 108                 return ret;
 109         else
 110                 return count;
 111 }
 112
 113 static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
 114 static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
 115
 116 static struct attribute *cpuidle_default_attrs[] = {
 117         &dev_attr_current_driver.attr,
 118         &dev_attr_current_governor_ro.attr,
 119         NULL
 120 };
 121
 122 static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
 123 static DEVICE_ATTR(current_governor, 0644, show_current_governor,
 124                    store_current_governor);
 125
 126 static struct attribute *cpuidle_switch_attrs[] = {
 127         &dev_attr_available_governors.attr,
 128         &dev_attr_current_driver.attr,
 129         &dev_attr_current_governor.attr,
 130         NULL
 131 };
 132
 133 static struct attribute_group cpuidle_attr_group = {
 134         .attrs = cpuidle_default_attrs,
 135         .name = "cpuidle",
 136 };
 137
 138 /**
 139  * cpuidle_add_interface - add CPU global sysfs attributes
 140  */
 141 int cpuidle_add_interface(struct device *dev)
 142 {
 143         if (sysfs_switch)
 144                 cpuidle_attr_group.attrs = cpuidle_switch_attrs;
 145
 146         return sysfs_create_group(&dev->kobj, &cpuidle_attr_group);
 147 }
 148
 149 /**
 150  * cpuidle_remove_interface - remove CPU global sysfs attributes
 151  */
 152 void cpuidle_remove_interface(struct device *dev)
 153 {
 154         sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
 155 }
 156
 157 struct cpuidle_attr {
 158         struct attribute attr;
 159         ssize_t (*show)(struct cpuidle_device *, char *);
 160         ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
 161 };
 162
 163 #define define_one_ro(_name, show) \
 164         static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 165 #define define_one_rw(_name, show, store) \
 166         static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
 167
 168 #define kobj_to_cpuidledev(k) container_of(k, struct cpuidle_device, kobj)
 169 #define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
 170 static ssize_t cpuidle_show(struct kobject * kobj, struct attribute * attr ,char * buf)
 171 {
 172         int ret = -EIO;
 173         struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
 174         struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
 175
 176         if (cattr->show) {
 177                 mutex_lock(&cpuidle_lock);
 178                 ret = cattr->show(dev, buf);
 179                 mutex_unlock(&cpuidle_lock);
 180         }
 181         return ret;
 182 }
 183
 184 static ssize_t cpuidle_store(struct kobject * kobj, struct attribute * attr,
 185                      const char * buf, size_t count)
 186 {
 187         int ret = -EIO;
 188         struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
 189         struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
 190
 191         if (cattr->store) {
 192                 mutex_lock(&cpuidle_lock);
 193                 ret = cattr->store(dev, buf, count);
 194                 mutex_unlock(&cpuidle_lock);
 195         }
 196         return ret;
 197 }
 198
 199 static const struct sysfs_ops cpuidle_sysfs_ops = {
 200         .show = cpuidle_show,
 201         .store = cpuidle_store,
 202 };
 203
 204 static void cpuidle_sysfs_release(struct kobject *kobj)
 205 {
 206         struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
 207
 208         complete(&dev->kobj_unregister);
 209 }
 210
 211 static struct kobj_type ktype_cpuidle = {
 212         .sysfs_ops = &cpuidle_sysfs_ops,
 213         .release = cpuidle_sysfs_release,
 214 };
 215
 216 struct cpuidle_state_attr {
 217         struct attribute attr;
 218         ssize_t (*show)(struct cpuidle_state *, \
 219                                         struct cpuidle_state_usage *, char *);
 220         ssize_t (*store)(struct cpuidle_state *, \
 221                         struct cpuidle_state_usage *, const char *, size_t);
 222 };
 223
 224 #define define_one_state_ro(_name, show) \
 225 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 226
 227 #define define_one_state_rw(_name, show, store) \
 228 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
 229
 230 #define define_show_state_function(_name) \
 231 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 232                          struct cpuidle_state_usage *state_usage, char *buf) \
 233 { \
 234         return sprintf(buf, "%u\n", state->_name);\
 235 }
 236
 237 #define define_store_state_ull_function(_name) \
 238 static ssize_t store_state_##_name(struct cpuidle_state *state, \
 239                 struct cpuidle_state_usage *state_usage, \
 240                 const char *buf, size_t size) \
 241 { \
 242         unsigned long long value; \
 243         int err; \
 244         if (!capable(CAP_SYS_ADMIN)) \
 245                 return -EPERM; \
 246         err = kstrtoull(buf, 0, &value); \
 247         if (err) \
 248                 return err; \
 249         if (value) \
 250                 state_usage->_name = 1; \
 251         else \
 252                 state_usage->_name = 0; \
 253         return size; \
 254 }
 255
 256 #define define_show_state_ull_function(_name) \
 257 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 258                         struct cpuidle_state_usage *state_usage, char *buf) \
 259 { \
 260         return sprintf(buf, "%llu\n", state_usage->_name);\
 261 }
 262
 263 #define define_show_state_str_function(_name) \
 264 static ssize_t show_state_##_name(struct cpuidle_state *state, \
 265                         struct cpuidle_state_usage *state_usage, char *buf) \
 266 { \
 267         if (state->_name[0] == '\0')\
 268                 return sprintf(buf, "<null>\n");\
 269         return sprintf(buf, "%s\n", state->_name);\
 270 }
 271
 272 define_show_state_function(exit_latency)
 273 define_show_state_function(power_usage)
 274 define_show_state_ull_function(usage)
 275 define_show_state_ull_function(time)
 276 define_show_state_str_function(name)
 277 define_show_state_str_function(desc)
 278 define_show_state_ull_function(disable)
 279 define_store_state_ull_function(disable)
 280
 281 define_one_state_ro(name, show_state_name);
 282 define_one_state_ro(desc, show_state_desc);
 283 define_one_state_ro(latency, show_state_exit_latency);
 284 define_one_state_ro(power, show_state_power_usage);
 285 define_one_state_ro(usage, show_state_usage);
 286 define_one_state_ro(time, show_state_time);
 287 define_one_state_rw(disable, show_state_disable, store_state_disable);
 288
 289 static struct attribute *cpuidle_state_default_attrs[] = {
 290         &attr_name.attr,
 291         &attr_desc.attr,
 292         &attr_latency.attr,
 293         &attr_power.attr,
 294         &attr_usage.attr,
 295         &attr_time.attr,
 296         &attr_disable.attr,
 297         NULL
 298 };
 299
 300 struct cpuidle_state_kobj {
 301         struct cpuidle_state *state;
 302         struct cpuidle_state_usage *state_usage;
 303         struct completion kobj_unregister;
 304         struct kobject kobj;
 305 };
 306
 307 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
 308 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
 309 #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
 310 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
 311 static ssize_t cpuidle_state_show(struct kobject * kobj,
 312         struct attribute * attr ,char * buf)
 313 {
 314         int ret = -EIO;
 315         struct cpuidle_state *state = kobj_to_state(kobj);
 316         struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
 317         struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
 318
 319         if (cattr->show)
 320                 ret = cattr->show(state, state_usage, buf);
 321
 322         return ret;
 323 }
 324
 325 static ssize_t cpuidle_state_store(struct kobject *kobj,
 326         struct attribute *attr, const char *buf, size_t size)
 327 {
 328         int ret = -EIO;
 329         struct cpuidle_state *state = kobj_to_state(kobj);
 330         struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
 331         struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
 332
 333         if (cattr->store)
 334                 ret = cattr->store(state, state_usage, buf, size);
 335
 336         return ret;
 337 }
 338
 339 static const struct sysfs_ops cpuidle_state_sysfs_ops = {
 340         .show = cpuidle_state_show,
 341         .store = cpuidle_state_store,
 342 };
 343
 344 static void cpuidle_state_sysfs_release(struct kobject *kobj)
 345 {
 346         struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
 347
 348         complete(&state_obj->kobj_unregister);
 349 }
 350
 351 static struct kobj_type ktype_state_cpuidle = {
 352         .sysfs_ops = &cpuidle_state_sysfs_ops,
 353         .default_attrs = cpuidle_state_default_attrs,
 354         .release = cpuidle_state_sysfs_release,
 355 };
 356
 357 static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
 358 {
 359         kobject_put(&device->kobjs[i]->kobj);
 360         wait_for_completion(&device->kobjs[i]->kobj_unregister);
 361         kfree(device->kobjs[i]);
 362         device->kobjs[i] = NULL;
 363 }
 364
 365 /**
 366  * cpuidle_add_driver_sysfs - adds driver-specific sysfs attributes
 367  * @device: the target device
 368  */
 369 int cpuidle_add_state_sysfs(struct cpuidle_device *device)
 370 {
 371         int i, ret = -ENOMEM;
 372         struct cpuidle_state_kobj *kobj;
 373         struct cpuidle_driver *drv = cpuidle_get_driver();
 374
 375         /* state statistics */
 376         for (i = 0; i < device->state_count; i++) {
 377                 kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
 378                 if (!kobj)
 379                         goto error_state;
 380                 kobj->state = &drv->states[i];
 381                 kobj->state_usage = &device->states_usage[i];
 382                 init_completion(&kobj->kobj_unregister);
 383
 384                 ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
 385                                            &device->kobj, "state%d", i);
 386                 if (ret) {
 387                         kfree(kobj);
 388                         goto error_state;
 389                 }
 390                 kobject_uevent(&kobj->kobj, KOBJ_ADD);
 391                 device->kobjs[i] = kobj;
 392         }
 393
 394         return 0;
 395
 396 error_state:
 397         for (i = i - 1; i >= 0; i--)
 398                 cpuidle_free_state_kobj(device, i);
 399         return ret;
 400 }
 401
 402 /**
 403  * cpuidle_remove_driver_sysfs - removes driver-specific sysfs attributes
 404  * @device: the target device
 405  */
 406 void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
 407 {
 408         int i;
 409
 410         for (i = 0; i < device->state_count; i++)
 411                 cpuidle_free_state_kobj(device, i);
 412 }
 413
 414 /**
 415  * cpuidle_add_sysfs - creates a sysfs instance for the target device
 416  * @dev: the target device
 417  */
 418 int cpuidle_add_sysfs(struct cpuidle_device *dev)
 419 {
 420         struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
 421         int error;
 422
 423         init_completion(&dev->kobj_unregister);
 424
 425         error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
 426                                      "cpuidle");
 427         if (!error)
 428                 kobject_uevent(&dev->kobj, KOBJ_ADD);
 429         return error;
 430 }
 431
 432 /**
 433  * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
 434  * @dev: the target device
 435  */
 436 void cpuidle_remove_sysfs(struct cpuidle_device *dev)
 437 {
 438         kobject_put(&dev->kobj);
 439         wait_for_completion(&dev->kobj_unregister);
 440 }