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 inline void 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 } 388