xref: /linux/drivers/cpuidle/sysfs.c (revision a67ff6a54095e27093ea501fb143fefe51a536c2) 
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 *, \
220 					struct cpuidle_state_usage *, char *);
221 	ssize_t (*store)(struct cpuidle_state *, const char *, size_t);
222 };
223 
224 #define define_one_state_ro(_name, show) \
225 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
226 
227 #define define_show_state_function(_name) \
228 static ssize_t show_state_##_name(struct cpuidle_state *state, \
229 			 struct cpuidle_state_usage *state_usage, char *buf) \
230 { \
231 	return sprintf(buf, "%u\n", state->_name);\
232 }
233 
234 #define define_show_state_ull_function(_name) \
235 static ssize_t show_state_##_name(struct cpuidle_state *state, \
236 			struct cpuidle_state_usage *state_usage, char *buf) \
237 { \
238 	return sprintf(buf, "%llu\n", state_usage->_name);\
239 }
240 
241 #define define_show_state_str_function(_name) \
242 static ssize_t show_state_##_name(struct cpuidle_state *state, \
243 			struct cpuidle_state_usage *state_usage, char *buf) \
244 { \
245 	if (state->_name[0] == '\0')\
246 		return sprintf(buf, "<null>\n");\
247 	return sprintf(buf, "%s\n", state->_name);\
248 }
249 
250 define_show_state_function(exit_latency)
251 define_show_state_function(power_usage)
252 define_show_state_ull_function(usage)
253 define_show_state_ull_function(time)
254 define_show_state_str_function(name)
255 define_show_state_str_function(desc)
256 
257 define_one_state_ro(name, show_state_name);
258 define_one_state_ro(desc, show_state_desc);
259 define_one_state_ro(latency, show_state_exit_latency);
260 define_one_state_ro(power, show_state_power_usage);
261 define_one_state_ro(usage, show_state_usage);
262 define_one_state_ro(time, show_state_time);
263 
264 static struct attribute *cpuidle_state_default_attrs[] = {
265 	&attr_name.attr,
266 	&attr_desc.attr,
267 	&attr_latency.attr,
268 	&attr_power.attr,
269 	&attr_usage.attr,
270 	&attr_time.attr,
271 	NULL
272 };
273 
274 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
275 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
276 #define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
277 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
278 static ssize_t cpuidle_state_show(struct kobject * kobj,
279 	struct attribute * attr ,char * buf)
280 {
281 	int ret = -EIO;
282 	struct cpuidle_state *state = kobj_to_state(kobj);
283 	struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
284 	struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
285 
286 	if (cattr->show)
287 		ret = cattr->show(state, state_usage, buf);
288 
289 	return ret;
290 }
291 
292 static const struct sysfs_ops cpuidle_state_sysfs_ops = {
293 	.show = cpuidle_state_show,
294 };
295 
296 static void cpuidle_state_sysfs_release(struct kobject *kobj)
297 {
298 	struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
299 
300 	complete(&state_obj->kobj_unregister);
301 }
302 
303 static struct kobj_type ktype_state_cpuidle = {
304 	.sysfs_ops = &cpuidle_state_sysfs_ops,
305 	.default_attrs = cpuidle_state_default_attrs,
306 	.release = cpuidle_state_sysfs_release,
307 };
308 
309 static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
310 {
311 	kobject_put(&device->kobjs[i]->kobj);
312 	wait_for_completion(&device->kobjs[i]->kobj_unregister);
313 	kfree(device->kobjs[i]);
314 	device->kobjs[i] = NULL;
315 }
316 
317 /**
318  * cpuidle_add_driver_sysfs - adds driver-specific sysfs attributes
319  * @device: the target device
320  */
321 int cpuidle_add_state_sysfs(struct cpuidle_device *device)
322 {
323 	int i, ret = -ENOMEM;
324 	struct cpuidle_state_kobj *kobj;
325 	struct cpuidle_driver *drv = cpuidle_get_driver();
326 
327 	/* state statistics */
328 	for (i = 0; i < device->state_count; i++) {
329 		kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
330 		if (!kobj)
331 			goto error_state;
332 		kobj->state = &drv->states[i];
333 		kobj->state_usage = &device->states_usage[i];
334 		init_completion(&kobj->kobj_unregister);
335 
336 		ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle, &device->kobj,
337 					   "state%d", i);
338 		if (ret) {
339 			kfree(kobj);
340 			goto error_state;
341 		}
342 		kobject_uevent(&kobj->kobj, KOBJ_ADD);
343 		device->kobjs[i] = kobj;
344 	}
345 
346 	return 0;
347 
348 error_state:
349 	for (i = i - 1; i >= 0; i--)
350 		cpuidle_free_state_kobj(device, i);
351 	return ret;
352 }
353 
354 /**
355  * cpuidle_remove_driver_sysfs - removes driver-specific sysfs attributes
356  * @device: the target device
357  */
358 void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
359 {
360 	int i;
361 
362 	for (i = 0; i < device->state_count; i++)
363 		cpuidle_free_state_kobj(device, i);
364 }
365 
366 /**
367  * cpuidle_add_sysfs - creates a sysfs instance for the target device
368  * @sysdev: the target device
369  */
370 int cpuidle_add_sysfs(struct sys_device *sysdev)
371 {
372 	int cpu = sysdev->id;
373 	struct cpuidle_device *dev;
374 	int error;
375 
376 	dev = per_cpu(cpuidle_devices, cpu);
377 	error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &sysdev->kobj,
378 				     "cpuidle");
379 	if (!error)
380 		kobject_uevent(&dev->kobj, KOBJ_ADD);
381 	return error;
382 }
383 
384 /**
385  * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
386  * @sysdev: the target device
387  */
388 void cpuidle_remove_sysfs(struct sys_device *sysdev)
389 {
390 	int cpu = sysdev->id;
391 	struct cpuidle_device *dev;
392 
393 	dev = per_cpu(cpuidle_devices, cpu);
394 	kobject_put(&dev->kobj);
395 }
396