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