summaryrefslogtreecommitdiffstats
path: root/drivers/cpuidle/sysfs.c
blob: 8a1ace1044768b2e8fa345eb546f55020757dc37 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
/*
 * sysfs.c - sysfs support
 *
 * (C) 2006-2007 Shaohua Li <shaohua.li@intel.com>
 *
 * This code is licenced under the GPL.
 */

#include <linux/kernel.h>
#include <linux/cpuidle.h>
#include <linux/sysfs.h>
#include <linux/slab.h>
#include <linux/cpu.h>

#include "cpuidle.h"

static unsigned int sysfs_switch;
static int __init cpuidle_sysfs_setup(char *unused)
{
	sysfs_switch = 1;
	return 1;
}
__setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);

static ssize_t show_available_governors(struct sysdev_class *class,
					struct sysdev_class_attribute *attr,
					char *buf)
{
	ssize_t i = 0;
	struct cpuidle_governor *tmp;

	mutex_lock(&cpuidle_lock);
	list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
		if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) - CPUIDLE_NAME_LEN - 2))
			goto out;
		i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
	}

out:
	i+= sprintf(&buf[i], "\n");
	mutex_unlock(&cpuidle_lock);
	return i;
}

static ssize_t show_current_driver(struct sysdev_class *class,
				   struct sysdev_class_attribute *attr,
				   char *buf)
{
	ssize_t ret;
	struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();

	spin_lock(&cpuidle_driver_lock);
	if (cpuidle_driver)
		ret = sprintf(buf, "%s\n", cpuidle_driver->name);
	else
		ret = sprintf(buf, "none\n");
	spin_unlock(&cpuidle_driver_lock);

	return ret;
}

static ssize_t show_current_governor(struct sysdev_class *class,
				     struct sysdev_class_attribute *attr,
				     char *buf)
{
	ssize_t ret;

	mutex_lock(&cpuidle_lock);
	if (cpuidle_curr_governor)
		ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
	else
		ret = sprintf(buf, "none\n");
	mutex_unlock(&cpuidle_lock);

	return ret;
}

static ssize_t store_current_governor(struct sysdev_class *class,
				      struct sysdev_class_attribute *attr,
				      const char *buf, size_t count)
{
	char gov_name[CPUIDLE_NAME_LEN];
	int ret = -EINVAL;
	size_t len = count;
	struct cpuidle_governor *gov;

	if (!len || len >= sizeof(gov_name))
		return -EINVAL;

	memcpy(gov_name, buf, len);
	gov_name[len] = '\0';
	if (gov_name[len - 1] == '\n')
		gov_name[--len] = '\0';

	mutex_lock(&cpuidle_lock);

	list_for_each_entry(gov, &cpuidle_governors, governor_list) {
		if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
			ret = cpuidle_switch_governor(gov);
			break;
		}
	}

	mutex_unlock(&cpuidle_lock);

	if (ret)
		return ret;
	else
		return count;
}

static SYSDEV_CLASS_ATTR(current_driver, 0444, show_current_driver, NULL);
static SYSDEV_CLASS_ATTR(current_governor_ro, 0444, show_current_governor,
			 NULL);

static struct attribute *cpuclass_default_attrs[] = {
	&attr_current_driver.attr,
	&attr_current_governor_ro.attr,
	NULL
};

static SYSDEV_CLASS_ATTR(available_governors, 0444, show_available_governors,
			 NULL);
static SYSDEV_CLASS_ATTR(current_governor, 0644, show_current_governor,
			 store_current_governor);

static struct attribute *cpuclass_switch_attrs[] = {
	&attr_available_governors.attr,
	&attr_current_driver.attr,
	&attr_current_governor.attr,
	NULL
};

static struct attribute_group cpuclass_attr_group = {
	.attrs = cpuclass_default_attrs,
	.name = "cpuidle",
};

/**
 * cpuidle_add_class_sysfs - add CPU global sysfs attributes
 */
int cpuidle_add_class_sysfs(struct sysdev_class *cls)
{
	if (sysfs_switch)
		cpuclass_attr_group.attrs = cpuclass_switch_attrs;

	return sysfs_create_group(&cls->kset.kobj, &cpuclass_attr_group);
}

/**
 * cpuidle_remove_class_sysfs - remove CPU global sysfs attributes
 */
void cpuidle_remove_class_sysfs(struct sysdev_class *cls)
{
	sysfs_remove_group(&cls->kset.kobj, &cpuclass_attr_group);
}

struct cpuidle_attr {
	struct attribute attr;
	ssize_t (*show)(struct cpuidle_device *, char *);
	ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
};

#define define_one_ro(_name, show) \
	static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
#define define_one_rw(_name, show, store) \
	static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)

#define kobj_to_cpuidledev(k) container_of(k, struct cpuidle_device, kobj)
#define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
static ssize_t cpuidle_show(struct kobject * kobj, struct attribute * attr ,char * buf)
{
	int ret = -EIO;
	struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
	struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);

	if (cattr->show) {
		mutex_lock(&cpuidle_lock);
		ret = cattr->show(dev, buf);
		mutex_unlock(&cpuidle_lock);
	}
	return ret;
}

static ssize_t cpuidle_store(struct kobject * kobj, struct attribute * attr,
		     const char * buf, size_t count)
{
	int ret = -EIO;
	struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
	struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);

	if (cattr->store) {
		mutex_lock(&cpuidle_lock);
		ret = cattr->store(dev, buf, count);
		mutex_unlock(&cpuidle_lock);
	}
	return ret;
}

static const struct sysfs_ops cpuidle_sysfs_ops = {
	.show = cpuidle_show,
	.store = cpuidle_store,
};

static void cpuidle_sysfs_release(struct kobject *kobj)
{
	struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);

	complete(&dev->kobj_unregister);
}

static struct kobj_type ktype_cpuidle = {
	.sysfs_ops = &cpuidle_sysfs_ops,
	.release = cpuidle_sysfs_release,
};

struct cpuidle_state_attr {
	struct attribute attr;
	ssize_t (*show)(struct cpuidle_state *, \
					struct cpuidle_state_usage *, char *);
	ssize_t (*store)(struct cpuidle_state *, const char *, size_t);
};

#define define_one_state_ro(_name, show) \
static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)

#define define_show_state_function(_name) \
static ssize_t show_state_##_name(struct cpuidle_state *state, \
			 struct cpuidle_state_usage *state_usage, char *buf) \
{ \
	return sprintf(buf, "%u\n", state->_name);\
}

#define define_show_state_ull_function(_name) \
static ssize_t show_state_##_name(struct cpuidle_state *state, \
			struct cpuidle_state_usage *state_usage, char *buf) \
{ \
	return sprintf(buf, "%llu\n", state_usage->_name);\
}

#define define_show_state_str_function(_name) \
static ssize_t show_state_##_name(struct cpuidle_state *state, \
			struct cpuidle_state_usage *state_usage, char *buf) \
{ \
	if (state->_name[0] == '\0')\
		return sprintf(buf, "<null>\n");\
	return sprintf(buf, "%s\n", state->_name);\
}

define_show_state_function(exit_latency)
define_show_state_function(power_usage)
define_show_state_ull_function(usage)
define_show_state_ull_function(time)
define_show_state_str_function(name)
define_show_state_str_function(desc)

define_one_state_ro(name, show_state_name);
define_one_state_ro(desc, show_state_desc);
define_one_state_ro(latency, show_state_exit_latency);
define_one_state_ro(power, show_state_power_usage);
define_one_state_ro(usage, show_state_usage);
define_one_state_ro(time, show_state_time);

static struct attribute *cpuidle_state_default_attrs[] = {
	&attr_name.attr,
	&attr_desc.attr,
	&attr_latency.attr,
	&attr_power.attr,
	&attr_usage.attr,
	&attr_time.attr,
	NULL
};

#define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
#define kobj_to_state(k) (kobj_to_state_obj(k)->state)
#define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
#define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
static ssize_t cpuidle_state_show(struct kobject * kobj,
	struct attribute * attr ,char * buf)
{
	int ret = -EIO;
	struct cpuidle_state *state = kobj_to_state(kobj);
	struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
	struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);

	if (cattr->show)
		ret = cattr->show(state, state_usage, buf);

	return ret;
}

static const struct sysfs_ops cpuidle_state_sysfs_ops = {
	.show = cpuidle_state_show,
};

static void cpuidle_state_sysfs_release(struct kobject *kobj)
{
	struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);

	complete(&state_obj->kobj_unregister);
}

static struct kobj_type ktype_state_cpuidle = {
	.sysfs_ops = &cpuidle_state_sysfs_ops,
	.default_attrs = cpuidle_state_default_attrs,
	.release = cpuidle_state_sysfs_release,
};

static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
{
	kobject_put(&device->kobjs[i]->kobj);
	wait_for_completion(&device->kobjs[i]->kobj_unregister);
	kfree(device->kobjs[i]);
	device->kobjs[i] = NULL;
}

/**
 * cpuidle_add_driver_sysfs - adds driver-specific sysfs attributes
 * @device: the target device
 */
int cpuidle_add_state_sysfs(struct cpuidle_device *device)
{
	int i, ret = -ENOMEM;
	struct cpuidle_state_kobj *kobj;

	/* state statistics */
	for (i = 0; i < device->state_count; i++) {
		kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
		if (!kobj)
			goto error_state;
		kobj->state = &device->states[i];
		kobj->state_usage = &device->states_usage[i];
		init_completion(&kobj->kobj_unregister);

		ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle, &device->kobj,
					   "state%d", i);
		if (ret) {
			kfree(kobj);
			goto error_state;
		}
		kobject_uevent(&kobj->kobj, KOBJ_ADD);
		device->kobjs[i] = kobj;
	}

	return 0;

error_state:
	for (i = i - 1; i >= 0; i--)
		cpuidle_free_state_kobj(device, i);
	return ret;
}

/**
 * cpuidle_remove_driver_sysfs - removes driver-specific sysfs attributes
 * @device: the target device
 */
void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
{
	int i;

	for (i = 0; i < device->state_count; i++)
		cpuidle_free_state_kobj(device, i);
}

/**
 * cpuidle_add_sysfs - creates a sysfs instance for the target device
 * @sysdev: the target device
 */
int cpuidle_add_sysfs(struct sys_device *sysdev)
{
	int cpu = sysdev->id;
	struct cpuidle_device *dev;
	int error;

	dev = per_cpu(cpuidle_devices, cpu);
	error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &sysdev->kobj,
				     "cpuidle");
	if (!error)
		kobject_uevent(&dev->kobj, KOBJ_ADD);
	return error;
}

/**
 * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
 * @sysdev: the target device
 */
void cpuidle_remove_sysfs(struct sys_device *sysdev)
{
	int cpu = sysdev->id;
	struct cpuidle_device *dev;

	dev = per_cpu(cpuidle_devices, cpu);
	kobject_put(&dev->kobj);
}
OpenPOWER on IntegriCloud