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 } 387