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