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