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