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Diffstat (limited to 'drivers/cpuidle/sysfs.c')
-rw-r--r--drivers/cpuidle/sysfs.c361
1 files changed, 361 insertions, 0 deletions
diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
new file mode 100644
index 000000000000..0f3515e77d4b
--- /dev/null
+++ b/drivers/cpuidle/sysfs.c
@@ -0,0 +1,361 @@
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
16static unsigned int sysfs_switch;
17static 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
24static 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
36out:
37 i+= sprintf(&buf[i], "\n");
38 mutex_unlock(&cpuidle_lock);
39 return i;
40}
41
42static 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
56static 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
70static 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
103static SYSDEV_ATTR(current_driver, 0444, show_current_driver, NULL);
104static SYSDEV_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
105
106static struct attribute *cpuclass_default_attrs[] = {
107 &attr_current_driver.attr,
108 &attr_current_governor_ro.attr,
109 NULL
110};
111
112static SYSDEV_ATTR(available_governors, 0444, show_available_governors, NULL);
113static SYSDEV_ATTR(current_governor, 0644, show_current_governor,
114 store_current_governor);
115
116static struct attribute *cpuclass_switch_attrs[] = {
117 &attr_available_governors.attr,
118 &attr_current_driver.attr,
119 &attr_current_governor.attr,
120 NULL
121};
122
123static 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 */
131int 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 */
142void cpuidle_remove_class_sysfs(struct sysdev_class *cls)
143{
144 sysfs_remove_group(&cls->kset.kobj, &cpuclass_attr_group);
145}
146
147struct 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)
160static 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
174static 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
189static struct sysfs_ops cpuidle_sysfs_ops = {
190 .show = cpuidle_show,
191 .store = cpuidle_store,
192};
193
194static 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
201static struct kobj_type ktype_cpuidle = {
202 .sysfs_ops = &cpuidle_sysfs_ops,
203 .release = cpuidle_sysfs_release,
204};
205
206struct 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) \
213static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
214
215#define define_show_state_function(_name) \
216static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
217{ \
218 return sprintf(buf, "%u\n", state->_name);\
219}
220
221static ssize_t show_state_name(struct cpuidle_state *state, char *buf)
222{
223 return sprintf(buf, "%s\n", state->name);
224}
225
226define_show_state_function(exit_latency)
227define_show_state_function(power_usage)
228define_show_state_function(usage)
229define_show_state_function(time)
230define_one_state_ro(name, show_state_name);
231define_one_state_ro(latency, show_state_exit_latency);
232define_one_state_ro(power, show_state_power_usage);
233define_one_state_ro(usage, show_state_usage);
234define_one_state_ro(time, show_state_time);
235
236static 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)
248static 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
261static struct sysfs_ops cpuidle_state_sysfs_ops = {
262 .show = cpuidle_state_show,
263};
264
265static 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
272static 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
278static 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 */
290int 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
316error_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 */
326void 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 */
338int 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 */
354void 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}