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