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_ull_function(_name) \ 222 static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \ 223 { \ 224 return sprintf(buf, "%llu\n", state->_name);\ 225 } 226 227 #define define_show_state_str_function(_name) \ 228 static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \ 229 { \ 230 if (state->_name[0] == '\0')\ 231 return sprintf(buf, "<null>\n");\ 232 return sprintf(buf, "%s\n", state->_name);\ 233 } 234 235 define_show_state_function(exit_latency) 236 define_show_state_function(power_usage) 237 define_show_state_ull_function(usage) 238 define_show_state_ull_function(time) 239 define_show_state_str_function(name) 240 define_show_state_str_function(desc) 241 242 define_one_state_ro(name, show_state_name); 243 define_one_state_ro(desc, show_state_desc); 244 define_one_state_ro(latency, show_state_exit_latency); 245 define_one_state_ro(power, show_state_power_usage); 246 define_one_state_ro(usage, show_state_usage); 247 define_one_state_ro(time, show_state_time); 248 249 static struct attribute *cpuidle_state_default_attrs[] = { 250 &attr_name.attr, 251 &attr_desc.attr, 252 &attr_latency.attr, 253 &attr_power.attr, 254 &attr_usage.attr, 255 &attr_time.attr, 256 NULL 257 }; 258 259 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj) 260 #define kobj_to_state(k) (kobj_to_state_obj(k)->state) 261 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr) 262 static ssize_t cpuidle_state_show(struct kobject * kobj, 263 struct attribute * attr ,char * buf) 264 { 265 int ret = -EIO; 266 struct cpuidle_state *state = kobj_to_state(kobj); 267 struct cpuidle_state_attr * cattr = attr_to_stateattr(attr); 268 269 if (cattr->show) 270 ret = cattr->show(state, buf); 271 272 return ret; 273 } 274 275 static struct sysfs_ops cpuidle_state_sysfs_ops = { 276 .show = cpuidle_state_show, 277 }; 278 279 static void cpuidle_state_sysfs_release(struct kobject *kobj) 280 { 281 struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj); 282 283 complete(&state_obj->kobj_unregister); 284 } 285 286 static struct kobj_type ktype_state_cpuidle = { 287 .sysfs_ops = &cpuidle_state_sysfs_ops, 288 .default_attrs = cpuidle_state_default_attrs, 289 .release = cpuidle_state_sysfs_release, 290 }; 291 292 static void inline cpuidle_free_state_kobj(struct cpuidle_device *device, int i) 293 { 294 kobject_put(&device->kobjs[i]->kobj); 295 wait_for_completion(&device->kobjs[i]->kobj_unregister); 296 kfree(device->kobjs[i]); 297 device->kobjs[i] = NULL; 298 } 299 300 /** 301 * cpuidle_add_driver_sysfs - adds driver-specific sysfs attributes 302 * @device: the target device 303 */ 304 int cpuidle_add_state_sysfs(struct cpuidle_device *device) 305 { 306 int i, ret = -ENOMEM; 307 struct cpuidle_state_kobj *kobj; 308 309 /* state statistics */ 310 for (i = 0; i < device->state_count; i++) { 311 kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL); 312 if (!kobj) 313 goto error_state; 314 kobj->state = &device->states[i]; 315 init_completion(&kobj->kobj_unregister); 316 317 ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle, &device->kobj, 318 "state%d", i); 319 if (ret) { 320 kfree(kobj); 321 goto error_state; 322 } 323 kobject_uevent(&kobj->kobj, KOBJ_ADD); 324 device->kobjs[i] = kobj; 325 } 326 327 return 0; 328 329 error_state: 330 for (i = i - 1; i >= 0; i--) 331 cpuidle_free_state_kobj(device, i); 332 return ret; 333 } 334 335 /** 336 * cpuidle_remove_driver_sysfs - removes driver-specific sysfs attributes 337 * @device: the target device 338 */ 339 void cpuidle_remove_state_sysfs(struct cpuidle_device *device) 340 { 341 int i; 342 343 for (i = 0; i < device->state_count; i++) 344 cpuidle_free_state_kobj(device, i); 345 } 346 347 /** 348 * cpuidle_add_sysfs - creates a sysfs instance for the target device 349 * @sysdev: the target device 350 */ 351 int cpuidle_add_sysfs(struct sys_device *sysdev) 352 { 353 int cpu = sysdev->id; 354 struct cpuidle_device *dev; 355 int error; 356 357 dev = per_cpu(cpuidle_devices, cpu); 358 error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &sysdev->kobj, 359 "cpuidle"); 360 if (!error) 361 kobject_uevent(&dev->kobj, KOBJ_ADD); 362 return error; 363 } 364 365 /** 366 * cpuidle_remove_sysfs - deletes a sysfs instance on the target device 367 * @sysdev: the target device 368 */ 369 void cpuidle_remove_sysfs(struct sys_device *sysdev) 370 { 371 int cpu = sysdev->id; 372 struct cpuidle_device *dev; 373 374 dev = per_cpu(cpuidle_devices, cpu); 375 kobject_put(&dev->kobj); 376 } 377