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/cpu.h>
  13
  14 #include "cpuidle.h"
  15
  16 static unsigned int sysfs_switch;
  17 static int __init cpuidle_sysfs_setup(char *unused)
  18 {
  19         sysfs_switch = 1;
  20         return 1;
  21 }
  22 __setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);
  23
  24 static ssize_t show_available_governors(struct sys_device *dev,
  25                 struct sysdev_attribute *attr, char *buf)
  26 {
  27         ssize_t i = 0;
  28         struct cpuidle_governor *tmp;
  29
  30         mutex_lock(&cpuidle_lock);
  31         list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
  32                 if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) - CPUIDLE_NAME_LEN - 2))
  33                         goto out;
  34                 i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
  35         }
  36
  37 out:
  38         i+= sprintf(&buf[i], "\n");
  39         mutex_unlock(&cpuidle_lock);
  40         return i;
  41 }
  42
  43 static ssize_t show_current_driver(struct sys_device *dev,
  44                 struct sysdev_attribute *attr, char *buf)
  45 {
  46         ssize_t ret;
  47
  48         spin_lock(&cpuidle_driver_lock);
  49         if (cpuidle_curr_driver)
  50                 ret = sprintf(buf, "%s\n", cpuidle_curr_driver->name);
  51         else
  52                 ret = sprintf(buf, "none\n");
  53         spin_unlock(&cpuidle_driver_lock);
  54
  55         return ret;
  56 }
  57
  58 static ssize_t show_current_governor(struct sys_device *dev,
  59                         struct sysdev_attribute *attr, char *buf)
  60 {
  61         ssize_t ret;
  62
  63         mutex_lock(&cpuidle_lock);
  64         if (cpuidle_curr_governor)
  65                 ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
  66         else
  67                 ret = sprintf(buf, "none\n");
  68         mutex_unlock(&cpuidle_lock);
  69
  70         return ret;
  71 }
  72
  73 static ssize_t store_current_governor(struct sys_device *dev,
  74         struct sysdev_attribute *attr,
  75         const char *buf, size_t count)
  76 {
  77         char gov_name[CPUIDLE_NAME_LEN];
  78         int ret = -EINVAL;
  79         size_t len = count;
  80         struct cpuidle_governor *gov;
  81
  82         if (!len || len >= sizeof(gov_name))
  83                 return -EINVAL;
  84
  85         memcpy(gov_name, buf, len);
  86         gov_name[len] = '\0';
  87         if (gov_name[len - 1] == '\n')
  88                 gov_name[--len] = '\0';
  89
  90         mutex_lock(&cpuidle_lock);
  91
  92         list_for_each_entry(gov, &cpuidle_governors, governor_list) {
  93                 if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
  94                         ret = cpuidle_switch_governor(gov);
  95                         break;
  96                 }
  97         }
  98
  99         mutex_unlock(&cpuidle_lock);
 100
 101         if (ret)
 102                 return ret;
 103         else
 104                 return count;
 105 }
 106
 107 static SYSDEV_ATTR(current_driver, 0444, show_current_driver, NULL);
 108 static SYSDEV_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
 109
 110 static struct attribute *cpuclass_default_attrs[] = {
 111         &attr_current_driver.attr,
 112         &attr_current_governor_ro.attr,
 113         NULL
 114 };
 115
 116 static SYSDEV_ATTR(available_governors, 0444, show_available_governors, NULL);
 117 static SYSDEV_ATTR(current_governor, 0644, show_current_governor,
 118         store_current_governor);
 119
 120 static struct attribute *cpuclass_switch_attrs[] = {
 121         &attr_available_governors.attr,
 122         &attr_current_driver.attr,
 123         &attr_current_governor.attr,
 124         NULL
 125 };
 126
 127 static struct attribute_group cpuclass_attr_group = {
 128         .attrs = cpuclass_default_attrs,
 129         .name = "cpuidle",
 130 };
 131
 132 /**
 133  * cpuidle_add_class_sysfs - add CPU global sysfs attributes
 134  */
 135 int cpuidle_add_class_sysfs(struct sysdev_class *cls)
 136 {
 137         if (sysfs_switch)
 138                 cpuclass_attr_group.attrs = cpuclass_switch_attrs;
 139
 140         return sysfs_create_group(&cls->kset.kobj, &cpuclass_attr_group);
 141 }
 142
 143 /**
 144  * cpuidle_remove_class_sysfs - remove CPU global sysfs attributes
 145  */
 146 void cpuidle_remove_class_sysfs(struct sysdev_class *cls)
 147 {
 148         sysfs_remove_group(&cls->kset.kobj, &cpuclass_attr_group);
 149 }
 150
 151 struct cpuidle_attr {
 152         struct attribute attr;
 153         ssize_t (*show)(struct cpuidle_device *, char *);
 154         ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
 155 };
 156
 157 #define define_one_ro(_name, show) \
 158         static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 159 #define define_one_rw(_name, show, store) \
 160         static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
 161
 162 #define kobj_to_cpuidledev(k) container_of(k, struct cpuidle_device, kobj)
 163 #define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
 164 static ssize_t cpuidle_show(struct kobject * kobj, struct attribute * attr ,char * buf)
 165 {
 166         int ret = -EIO;
 167         struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
 168         struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
 169
 170         if (cattr->show) {
 171                 mutex_lock(&cpuidle_lock);
 172                 ret = cattr->show(dev, buf);
 173                 mutex_unlock(&cpuidle_lock);
 174         }
 175         return ret;
 176 }
 177
 178 static ssize_t cpuidle_store(struct kobject * kobj, struct attribute * attr,
 179                      const char * buf, size_t count)
 180 {
 181         int ret = -EIO;
 182         struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
 183         struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
 184
 185         if (cattr->store) {
 186                 mutex_lock(&cpuidle_lock);
 187                 ret = cattr->store(dev, buf, count);
 188                 mutex_unlock(&cpuidle_lock);
 189         }
 190         return ret;
 191 }
 192
 193 static struct sysfs_ops cpuidle_sysfs_ops = {
 194         .show = cpuidle_show,
 195         .store = cpuidle_store,
 196 };
 197
 198 static void cpuidle_sysfs_release(struct kobject *kobj)
 199 {
 200         struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
 201
 202         complete(&dev->kobj_unregister);
 203 }
 204
 205 static struct kobj_type ktype_cpuidle = {
 206         .sysfs_ops = &cpuidle_sysfs_ops,
 207         .release = cpuidle_sysfs_release,
 208 };
 209
 210 struct cpuidle_state_attr {
 211         struct attribute attr;
 212         ssize_t (*show)(struct cpuidle_state *, char *);
 213         ssize_t (*store)(struct cpuidle_state *, const char *, size_t);
 214 };
 215
 216 #define define_one_state_ro(_name, show) \
 217 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 218
 219 #define define_show_state_function(_name) \
 220 static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
 221 { \
 222         return sprintf(buf, "%u\n", state->_name);\
 223 }
 224
 225 #define define_show_state_ull_function(_name) \
 226 static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
 227 { \
 228         return sprintf(buf, "%llu\n", state->_name);\
 229 }
 230
 231 #define define_show_state_str_function(_name) \
 232 static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
 233 { \
 234         if (state->_name[0] == '\0')\
 235                 return sprintf(buf, "<null>\n");\
 236         return sprintf(buf, "%s\n", state->_name);\
 237 }
 238
 239 define_show_state_function(exit_latency)
 240 define_show_state_function(power_usage)
 241 define_show_state_ull_function(usage)
 242 define_show_state_ull_function(time)
 243 define_show_state_str_function(name)
 244 define_show_state_str_function(desc)
 245
 246 define_one_state_ro(name, show_state_name);
 247 define_one_state_ro(desc, show_state_desc);
 248 define_one_state_ro(latency, show_state_exit_latency);
 249 define_one_state_ro(power, show_state_power_usage);
 250 define_one_state_ro(usage, show_state_usage);
 251 define_one_state_ro(time, show_state_time);
 252
 253 static struct attribute *cpuidle_state_default_attrs[] = {
 254         &attr_name.attr,
 255         &attr_desc.attr,
 256         &attr_latency.attr,
 257         &attr_power.attr,
 258         &attr_usage.attr,
 259         &attr_time.attr,
 260         NULL
 261 };
 262
 263 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
 264 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
 265 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
 266 static ssize_t cpuidle_state_show(struct kobject * kobj,
 267         struct attribute * attr ,char * buf)
 268 {
 269         int ret = -EIO;
 270         struct cpuidle_state *state = kobj_to_state(kobj);
 271         struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
 272
 273         if (cattr->show)
 274                 ret = cattr->show(state, buf);
 275
 276         return ret;
 277 }
 278
 279 static struct sysfs_ops cpuidle_state_sysfs_ops = {
 280         .show = cpuidle_state_show,
 281 };
 282
 283 static void cpuidle_state_sysfs_release(struct kobject *kobj)
 284 {
 285         struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
 286
 287         complete(&state_obj->kobj_unregister);
 288 }
 289
 290 static struct kobj_type ktype_state_cpuidle = {
 291         .sysfs_ops = &cpuidle_state_sysfs_ops,
 292         .default_attrs = cpuidle_state_default_attrs,
 293         .release = cpuidle_state_sysfs_release,
 294 };
 295
 296 static void inline cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
 297 {
 298         kobject_put(&device->kobjs[i]->kobj);
 299         wait_for_completion(&device->kobjs[i]->kobj_unregister);
 300         kfree(device->kobjs[i]);
 301         device->kobjs[i] = NULL;
 302 }
 303
 304 /**
 305  * cpuidle_add_driver_sysfs - adds driver-specific sysfs attributes
 306  * @device: the target device
 307  */
 308 int cpuidle_add_state_sysfs(struct cpuidle_device *device)
 309 {
 310         int i, ret = -ENOMEM;
 311         struct cpuidle_state_kobj *kobj;
 312
 313         /* state statistics */
 314         for (i = 0; i < device->state_count; i++) {
 315                 kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
 316                 if (!kobj)
 317                         goto error_state;
 318                 kobj->state = &device->states[i];
 319                 init_completion(&kobj->kobj_unregister);
 320
 321                 ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle, &device->kobj,
 322                                            "state%d", i);
 323                 if (ret) {
 324                         kfree(kobj);
 325                         goto error_state;
 326                 }
 327                 kobject_uevent(&kobj->kobj, KOBJ_ADD);
 328                 device->kobjs[i] = kobj;
 329         }
 330
 331         return 0;
 332
 333 error_state:
 334         for (i = i - 1; i >= 0; i--)
 335                 cpuidle_free_state_kobj(device, i);
 336         return ret;
 337 }
 338
 339 /**
 340  * cpuidle_remove_driver_sysfs - removes driver-specific sysfs attributes
 341  * @device: the target device
 342  */
 343 void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
 344 {
 345         int i;
 346
 347         for (i = 0; i < device->state_count; i++)
 348                 cpuidle_free_state_kobj(device, i);
 349 }
 350
 351 /**
 352  * cpuidle_add_sysfs - creates a sysfs instance for the target device
 353  * @sysdev: the target device
 354  */
 355 int cpuidle_add_sysfs(struct sys_device *sysdev)
 356 {
 357         int cpu = sysdev->id;
 358         struct cpuidle_device *dev;
 359         int error;
 360
 361         dev = per_cpu(cpuidle_devices, cpu);
 362         error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &sysdev->kobj,
 363                                      "cpuidle");
 364         if (!error)
 365                 kobject_uevent(&dev->kobj, KOBJ_ADD);
 366         return error;
 367 }
 368
 369 /**
 370  * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
 371  * @sysdev: the target device
 372  */
 373 void cpuidle_remove_sysfs(struct sys_device *sysdev)
 374 {
 375         int cpu = sysdev->id;
 376         struct cpuidle_device *dev;
 377
 378         dev = per_cpu(cpuidle_devices, cpu);
 379         kobject_put(&dev->kobj);
 380 }