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
  51         spin_lock(&cpuidle_driver_lock);
  52         if (cpuidle_curr_driver)
  53                 ret = sprintf(buf, "%s\n", cpuidle_curr_driver->name);
  54         else
  55                 ret = sprintf(buf, "none\n");
  56         spin_unlock(&cpuidle_driver_lock);
  57
  58         return ret;
  59 }
  60
  61 static ssize_t show_current_governor(struct sysdev_class *class,
  62                                      struct sysdev_class_attribute *attr,
  63                                      char *buf)
  64 {
  65         ssize_t ret;
  66
  67         mutex_lock(&cpuidle_lock);
  68         if (cpuidle_curr_governor)
  69                 ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
  70         else
  71                 ret = sprintf(buf, "none\n");
  72         mutex_unlock(&cpuidle_lock);
  73
  74         return ret;
  75 }
  76
  77 static ssize_t store_current_governor(struct sysdev_class *class,
  78                                       struct sysdev_class_attribute *attr,
  79                                       const char *buf, size_t count)
  80 {
  81         char gov_name[CPUIDLE_NAME_LEN];
  82         int ret = -EINVAL;
  83         size_t len = count;
  84         struct cpuidle_governor *gov;
  85
  86         if (!len || len >= sizeof(gov_name))
  87                 return -EINVAL;
  88
  89         memcpy(gov_name, buf, len);
  90         gov_name[len] = '\0';
  91         if (gov_name[len - 1] == '\n')
  92                 gov_name[--len] = '\0';
  93
  94         mutex_lock(&cpuidle_lock);
  95
  96         list_for_each_entry(gov, &cpuidle_governors, governor_list) {
  97                 if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
  98                         ret = cpuidle_switch_governor(gov);
  99                         break;
 100                 }
 101         }
 102
 103         mutex_unlock(&cpuidle_lock);
 104
 105         if (ret)
 106                 return ret;
 107         else
 108                 return count;
 109 }
 110
 111 static SYSDEV_CLASS_ATTR(current_driver, 0444, show_current_driver, NULL);
 112 static SYSDEV_CLASS_ATTR(current_governor_ro, 0444, show_current_governor,
 113                          NULL);
 114
 115 static struct attribute *cpuclass_default_attrs[] = {
 116         &attr_current_driver.attr,
 117         &attr_current_governor_ro.attr,
 118         NULL
 119 };
 120
 121 static SYSDEV_CLASS_ATTR(available_governors, 0444, show_available_governors,
 122                          NULL);
 123 static SYSDEV_CLASS_ATTR(current_governor, 0644, show_current_governor,
 124                          store_current_governor);
 125
 126 static struct attribute *cpuclass_switch_attrs[] = {
 127         &attr_available_governors.attr,
 128         &attr_current_driver.attr,
 129         &attr_current_governor.attr,
 130         NULL
 131 };
 132
 133 static struct attribute_group cpuclass_attr_group = {
 134         .attrs = cpuclass_default_attrs,
 135         .name = "cpuidle",
 136 };
 137
 138 /**
 139  * cpuidle_add_class_sysfs - add CPU global sysfs attributes
 140  */
 141 int cpuidle_add_class_sysfs(struct sysdev_class *cls)
 142 {
 143         if (sysfs_switch)
 144                 cpuclass_attr_group.attrs = cpuclass_switch_attrs;
 145
 146         return sysfs_create_group(&cls->kset.kobj, &cpuclass_attr_group);
 147 }
 148
 149 /**
 150  * cpuidle_remove_class_sysfs - remove CPU global sysfs attributes
 151  */
 152 void cpuidle_remove_class_sysfs(struct sysdev_class *cls)
 153 {
 154         sysfs_remove_group(&cls->kset.kobj, &cpuclass_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 *, char *);
 219         ssize_t (*store)(struct cpuidle_state *, const char *, size_t);
 220 };
 221
 222 #define define_one_state_ro(_name, show) \
 223 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 224
 225 #define define_show_state_function(_name) \
 226 static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
 227 { \
 228         return sprintf(buf, "%u\n", state->_name);\
 229 }
 230
 231 #define define_show_state_ull_function(_name) \
 232 static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
 233 { \
 234         return sprintf(buf, "%llu\n", state->_name);\
 235 }
 236
 237 #define define_show_state_str_function(_name) \
 238 static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
 239 { \
 240         if (state->_name[0] == '\0')\
 241                 return sprintf(buf, "<null>\n");\
 242         return sprintf(buf, "%s\n", state->_name);\
 243 }
 244
 245 define_show_state_function(exit_latency)
 246 define_show_state_function(power_usage)
 247 define_show_state_ull_function(usage)
 248 define_show_state_ull_function(time)
 249 define_show_state_str_function(name)
 250 define_show_state_str_function(desc)
 251
 252 define_one_state_ro(name, show_state_name);
 253 define_one_state_ro(desc, show_state_desc);
 254 define_one_state_ro(latency, show_state_exit_latency);
 255 define_one_state_ro(power, show_state_power_usage);
 256 define_one_state_ro(usage, show_state_usage);
 257 define_one_state_ro(time, show_state_time);
 258
 259 static struct attribute *cpuidle_state_default_attrs[] = {
 260         &attr_name.attr,
 261         &attr_desc.attr,
 262         &attr_latency.attr,
 263         &attr_power.attr,
 264         &attr_usage.attr,
 265         &attr_time.attr,
 266         NULL
 267 };
 268
 269 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
 270 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
 271 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
 272 static ssize_t cpuidle_state_show(struct kobject * kobj,
 273         struct attribute * attr ,char * buf)
 274 {
 275         int ret = -EIO;
 276         struct cpuidle_state *state = kobj_to_state(kobj);
 277         struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
 278
 279         if (cattr->show)
 280                 ret = cattr->show(state, buf);
 281
 282         return ret;
 283 }
 284
 285 static const struct sysfs_ops cpuidle_state_sysfs_ops = {
 286         .show = cpuidle_state_show,
 287 };
 288
 289 static void cpuidle_state_sysfs_release(struct kobject *kobj)
 290 {
 291         struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
 292
 293         complete(&state_obj->kobj_unregister);
 294 }
 295
 296 static struct kobj_type ktype_state_cpuidle = {
 297         .sysfs_ops = &cpuidle_state_sysfs_ops,
 298         .default_attrs = cpuidle_state_default_attrs,
 299         .release = cpuidle_state_sysfs_release,
 300 };
 301
 302 static void inline cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
 303 {
 304         kobject_put(&device->kobjs[i]->kobj);
 305         wait_for_completion(&device->kobjs[i]->kobj_unregister);
 306         kfree(device->kobjs[i]);
 307         device->kobjs[i] = NULL;
 308 }
 309
 310 /**
 311  * cpuidle_add_driver_sysfs - adds driver-specific sysfs attributes
 312  * @device: the target device
 313  */
 314 int cpuidle_add_state_sysfs(struct cpuidle_device *device)
 315 {
 316         int i, ret = -ENOMEM;
 317         struct cpuidle_state_kobj *kobj;
 318
 319         /* state statistics */
 320         for (i = 0; i < device->state_count; i++) {
 321                 kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
 322                 if (!kobj)
 323                         goto error_state;
 324                 kobj->state = &device->states[i];
 325                 init_completion(&kobj->kobj_unregister);
 326
 327                 ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle, &device->kobj,
 328                                            "state%d", i);
 329                 if (ret) {
 330                         kfree(kobj);
 331                         goto error_state;
 332                 }
 333                 kobject_uevent(&kobj->kobj, KOBJ_ADD);
 334                 device->kobjs[i] = kobj;
 335         }
 336
 337         return 0;
 338
 339 error_state:
 340         for (i = i - 1; i >= 0; i--)
 341                 cpuidle_free_state_kobj(device, i);
 342         return ret;
 343 }
 344
 345 /**
 346  * cpuidle_remove_driver_sysfs - removes driver-specific sysfs attributes
 347  * @device: the target device
 348  */
 349 void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
 350 {
 351         int i;
 352
 353         for (i = 0; i < device->state_count; i++)
 354                 cpuidle_free_state_kobj(device, i);
 355 }
 356
 357 /**
 358  * cpuidle_add_sysfs - creates a sysfs instance for the target device
 359  * @sysdev: the target device
 360  */
 361 int cpuidle_add_sysfs(struct sys_device *sysdev)
 362 {
 363         int cpu = sysdev->id;
 364         struct cpuidle_device *dev;
 365         int error;
 366
 367         dev = per_cpu(cpuidle_devices, cpu);
 368         error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &sysdev->kobj,
 369                                      "cpuidle");
 370         if (!error)
 371                 kobject_uevent(&dev->kobj, KOBJ_ADD);
 372         return error;
 373 }
 374
 375 /**
 376  * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
 377  * @sysdev: the target device
 378  */
 379 void cpuidle_remove_sysfs(struct sys_device *sysdev)
 380 {
 381         int cpu = sysdev->id;
 382         struct cpuidle_device *dev;
 383
 384         dev = per_cpu(cpuidle_devices, cpu);
 385         kobject_put(&dev->kobj);
 386 }