[go: nahoru, domu]
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#include <linux/completion.h>
15#include <linux/capability.h>
16#include <linux/device.h>
17#include <linux/kobject.h>
18
19#include "cpuidle.h"
20
21static unsigned int sysfs_switch;
22static int __init cpuidle_sysfs_setup(char *unused)
23{
24	sysfs_switch = 1;
25	return 1;
26}
27__setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);
28
29static ssize_t show_available_governors(struct device *dev,
30					struct device_attribute *attr,
31					char *buf)
32{
33	ssize_t i = 0;
34	struct cpuidle_governor *tmp;
35
36	mutex_lock(&cpuidle_lock);
37	list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
38		if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) -
39				    CPUIDLE_NAME_LEN - 2))
40			goto out;
41		i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
42	}
43
44out:
45	i+= sprintf(&buf[i], "\n");
46	mutex_unlock(&cpuidle_lock);
47	return i;
48}
49
50static ssize_t show_current_driver(struct device *dev,
51				   struct device_attribute *attr,
52				   char *buf)
53{
54	ssize_t ret;
55	struct cpuidle_driver *drv;
56
57	spin_lock(&cpuidle_driver_lock);
58	drv = cpuidle_get_driver();
59	if (drv)
60		ret = sprintf(buf, "%s\n", drv->name);
61	else
62		ret = sprintf(buf, "none\n");
63	spin_unlock(&cpuidle_driver_lock);
64
65	return ret;
66}
67
68static ssize_t show_current_governor(struct device *dev,
69				     struct device_attribute *attr,
70				     char *buf)
71{
72	ssize_t ret;
73
74	mutex_lock(&cpuidle_lock);
75	if (cpuidle_curr_governor)
76		ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
77	else
78		ret = sprintf(buf, "none\n");
79	mutex_unlock(&cpuidle_lock);
80
81	return ret;
82}
83
84static ssize_t store_current_governor(struct device *dev,
85				      struct device_attribute *attr,
86				      const char *buf, size_t count)
87{
88	char gov_name[CPUIDLE_NAME_LEN];
89	int ret = -EINVAL;
90	size_t len = count;
91	struct cpuidle_governor *gov;
92
93	if (!len || len >= sizeof(gov_name))
94		return -EINVAL;
95
96	memcpy(gov_name, buf, len);
97	gov_name[len] = '\0';
98	if (gov_name[len - 1] == '\n')
99		gov_name[--len] = '\0';
100
101	mutex_lock(&cpuidle_lock);
102
103	list_for_each_entry(gov, &cpuidle_governors, governor_list) {
104		if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
105			ret = cpuidle_switch_governor(gov);
106			break;
107		}
108	}
109
110	mutex_unlock(&cpuidle_lock);
111
112	if (ret)
113		return ret;
114	else
115		return count;
116}
117
118static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
119static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
120
121static struct attribute *cpuidle_default_attrs[] = {
122	&dev_attr_current_driver.attr,
123	&dev_attr_current_governor_ro.attr,
124	NULL
125};
126
127static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
128static DEVICE_ATTR(current_governor, 0644, show_current_governor,
129		   store_current_governor);
130
131static struct attribute *cpuidle_switch_attrs[] = {
132	&dev_attr_available_governors.attr,
133	&dev_attr_current_driver.attr,
134	&dev_attr_current_governor.attr,
135	NULL
136};
137
138static struct attribute_group cpuidle_attr_group = {
139	.attrs = cpuidle_default_attrs,
140	.name = "cpuidle",
141};
142
143/**
144 * cpuidle_add_interface - add CPU global sysfs attributes
145 */
146int cpuidle_add_interface(struct device *dev)
147{
148	if (sysfs_switch)
149		cpuidle_attr_group.attrs = cpuidle_switch_attrs;
150
151	return sysfs_create_group(&dev->kobj, &cpuidle_attr_group);
152}
153
154/**
155 * cpuidle_remove_interface - remove CPU global sysfs attributes
156 */
157void cpuidle_remove_interface(struct device *dev)
158{
159	sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
160}
161
162struct cpuidle_attr {
163	struct attribute attr;
164	ssize_t (*show)(struct cpuidle_device *, char *);
165	ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
166};
167
168#define define_one_ro(_name, show) \
169	static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
170#define define_one_rw(_name, show, store) \
171	static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
172
173#define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
174
175struct cpuidle_device_kobj {
176	struct cpuidle_device *dev;
177	struct completion kobj_unregister;
178	struct kobject kobj;
179};
180
181static inline struct cpuidle_device *to_cpuidle_device(struct kobject *kobj)
182{
183	struct cpuidle_device_kobj *kdev =
184		container_of(kobj, struct cpuidle_device_kobj, kobj);
185
186	return kdev->dev;
187}
188
189static ssize_t cpuidle_show(struct kobject *kobj, struct attribute *attr,
190			    char *buf)
191{
192	int ret = -EIO;
193	struct cpuidle_device *dev = to_cpuidle_device(kobj);
194	struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
195
196	if (cattr->show) {
197		mutex_lock(&cpuidle_lock);
198		ret = cattr->show(dev, buf);
199		mutex_unlock(&cpuidle_lock);
200	}
201	return ret;
202}
203
204static ssize_t cpuidle_store(struct kobject *kobj, struct attribute *attr,
205			     const char *buf, size_t count)
206{
207	int ret = -EIO;
208	struct cpuidle_device *dev = to_cpuidle_device(kobj);
209	struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
210
211	if (cattr->store) {
212		mutex_lock(&cpuidle_lock);
213		ret = cattr->store(dev, buf, count);
214		mutex_unlock(&cpuidle_lock);
215	}
216	return ret;
217}
218
219static const struct sysfs_ops cpuidle_sysfs_ops = {
220	.show = cpuidle_show,
221	.store = cpuidle_store,
222};
223
224static void cpuidle_sysfs_release(struct kobject *kobj)
225{
226	struct cpuidle_device_kobj *kdev =
227		container_of(kobj, struct cpuidle_device_kobj, kobj);
228
229	complete(&kdev->kobj_unregister);
230}
231
232static struct kobj_type ktype_cpuidle = {
233	.sysfs_ops = &cpuidle_sysfs_ops,
234	.release = cpuidle_sysfs_release,
235};
236
237struct cpuidle_state_attr {
238	struct attribute attr;
239	ssize_t (*show)(struct cpuidle_state *, \
240					struct cpuidle_state_usage *, char *);
241	ssize_t (*store)(struct cpuidle_state *, \
242			struct cpuidle_state_usage *, const char *, size_t);
243};
244
245#define define_one_state_ro(_name, show) \
246static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
247
248#define define_one_state_rw(_name, show, store) \
249static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
250
251#define define_show_state_function(_name) \
252static ssize_t show_state_##_name(struct cpuidle_state *state, \
253			 struct cpuidle_state_usage *state_usage, char *buf) \
254{ \
255	return sprintf(buf, "%u\n", state->_name);\
256}
257
258#define define_store_state_ull_function(_name) \
259static ssize_t store_state_##_name(struct cpuidle_state *state, \
260				   struct cpuidle_state_usage *state_usage, \
261				   const char *buf, size_t size)	\
262{ \
263	unsigned long long value; \
264	int err; \
265	if (!capable(CAP_SYS_ADMIN)) \
266		return -EPERM; \
267	err = kstrtoull(buf, 0, &value); \
268	if (err) \
269		return err; \
270	if (value) \
271		state_usage->_name = 1; \
272	else \
273		state_usage->_name = 0; \
274	return size; \
275}
276
277#define define_show_state_ull_function(_name) \
278static ssize_t show_state_##_name(struct cpuidle_state *state, \
279				  struct cpuidle_state_usage *state_usage, \
280				  char *buf)				\
281{ \
282	return sprintf(buf, "%llu\n", state_usage->_name);\
283}
284
285#define define_show_state_str_function(_name) \
286static ssize_t show_state_##_name(struct cpuidle_state *state, \
287				  struct cpuidle_state_usage *state_usage, \
288				  char *buf)				\
289{ \
290	if (state->_name[0] == '\0')\
291		return sprintf(buf, "<null>\n");\
292	return sprintf(buf, "%s\n", state->_name);\
293}
294
295define_show_state_function(exit_latency)
296define_show_state_function(target_residency)
297define_show_state_function(power_usage)
298define_show_state_ull_function(usage)
299define_show_state_ull_function(time)
300define_show_state_str_function(name)
301define_show_state_str_function(desc)
302define_show_state_ull_function(disable)
303define_store_state_ull_function(disable)
304
305define_one_state_ro(name, show_state_name);
306define_one_state_ro(desc, show_state_desc);
307define_one_state_ro(latency, show_state_exit_latency);
308define_one_state_ro(residency, show_state_target_residency);
309define_one_state_ro(power, show_state_power_usage);
310define_one_state_ro(usage, show_state_usage);
311define_one_state_ro(time, show_state_time);
312define_one_state_rw(disable, show_state_disable, store_state_disable);
313
314static struct attribute *cpuidle_state_default_attrs[] = {
315	&attr_name.attr,
316	&attr_desc.attr,
317	&attr_latency.attr,
318	&attr_residency.attr,
319	&attr_power.attr,
320	&attr_usage.attr,
321	&attr_time.attr,
322	&attr_disable.attr,
323	NULL
324};
325
326struct cpuidle_state_kobj {
327	struct cpuidle_state *state;
328	struct cpuidle_state_usage *state_usage;
329	struct completion kobj_unregister;
330	struct kobject kobj;
331};
332
333#define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
334#define kobj_to_state(k) (kobj_to_state_obj(k)->state)
335#define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
336#define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
337
338static ssize_t cpuidle_state_show(struct kobject *kobj, struct attribute *attr,
339				  char * buf)
340{
341	int ret = -EIO;
342	struct cpuidle_state *state = kobj_to_state(kobj);
343	struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
344	struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
345
346	if (cattr->show)
347		ret = cattr->show(state, state_usage, buf);
348
349	return ret;
350}
351
352static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr,
353				   const char *buf, size_t size)
354{
355	int ret = -EIO;
356	struct cpuidle_state *state = kobj_to_state(kobj);
357	struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
358	struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
359
360	if (cattr->store)
361		ret = cattr->store(state, state_usage, buf, size);
362
363	return ret;
364}
365
366static const struct sysfs_ops cpuidle_state_sysfs_ops = {
367	.show = cpuidle_state_show,
368	.store = cpuidle_state_store,
369};
370
371static void cpuidle_state_sysfs_release(struct kobject *kobj)
372{
373	struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
374
375	complete(&state_obj->kobj_unregister);
376}
377
378static struct kobj_type ktype_state_cpuidle = {
379	.sysfs_ops = &cpuidle_state_sysfs_ops,
380	.default_attrs = cpuidle_state_default_attrs,
381	.release = cpuidle_state_sysfs_release,
382};
383
384static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
385{
386	kobject_put(&device->kobjs[i]->kobj);
387	wait_for_completion(&device->kobjs[i]->kobj_unregister);
388	kfree(device->kobjs[i]);
389	device->kobjs[i] = NULL;
390}
391
392/**
393 * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes
394 * @device: the target device
395 */
396static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
397{
398	int i, ret = -ENOMEM;
399	struct cpuidle_state_kobj *kobj;
400	struct cpuidle_device_kobj *kdev = device->kobj_dev;
401	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
402
403	/* state statistics */
404	for (i = 0; i < device->state_count; i++) {
405		kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
406		if (!kobj)
407			goto error_state;
408		kobj->state = &drv->states[i];
409		kobj->state_usage = &device->states_usage[i];
410		init_completion(&kobj->kobj_unregister);
411
412		ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
413					   &kdev->kobj, "state%d", i);
414		if (ret) {
415			kfree(kobj);
416			goto error_state;
417		}
418		kobject_uevent(&kobj->kobj, KOBJ_ADD);
419		device->kobjs[i] = kobj;
420	}
421
422	return 0;
423
424error_state:
425	for (i = i - 1; i >= 0; i--)
426		cpuidle_free_state_kobj(device, i);
427	return ret;
428}
429
430/**
431 * cpuidle_remove_driver_sysfs - removes the cpuidle states sysfs attributes
432 * @device: the target device
433 */
434static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
435{
436	int i;
437
438	for (i = 0; i < device->state_count; i++)
439		cpuidle_free_state_kobj(device, i);
440}
441
442#ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
443#define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
444#define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
445
446#define define_one_driver_ro(_name, show)                       \
447	static struct cpuidle_driver_attr attr_driver_##_name = \
448		__ATTR(_name, 0444, show, NULL)
449
450struct cpuidle_driver_kobj {
451	struct cpuidle_driver *drv;
452	struct completion kobj_unregister;
453	struct kobject kobj;
454};
455
456struct cpuidle_driver_attr {
457	struct attribute attr;
458	ssize_t (*show)(struct cpuidle_driver *, char *);
459	ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
460};
461
462static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
463{
464	ssize_t ret;
465
466	spin_lock(&cpuidle_driver_lock);
467	ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
468	spin_unlock(&cpuidle_driver_lock);
469
470	return ret;
471}
472
473static void cpuidle_driver_sysfs_release(struct kobject *kobj)
474{
475	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
476	complete(&driver_kobj->kobj_unregister);
477}
478
479static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
480				   char *buf)
481{
482	int ret = -EIO;
483	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
484	struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
485
486	if (dattr->show)
487		ret = dattr->show(driver_kobj->drv, buf);
488
489	return ret;
490}
491
492static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
493				    const char *buf, size_t size)
494{
495	int ret = -EIO;
496	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
497	struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
498
499	if (dattr->store)
500		ret = dattr->store(driver_kobj->drv, buf, size);
501
502	return ret;
503}
504
505define_one_driver_ro(name, show_driver_name);
506
507static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
508	.show = cpuidle_driver_show,
509	.store = cpuidle_driver_store,
510};
511
512static struct attribute *cpuidle_driver_default_attrs[] = {
513	&attr_driver_name.attr,
514	NULL
515};
516
517static struct kobj_type ktype_driver_cpuidle = {
518	.sysfs_ops = &cpuidle_driver_sysfs_ops,
519	.default_attrs = cpuidle_driver_default_attrs,
520	.release = cpuidle_driver_sysfs_release,
521};
522
523/**
524 * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
525 * @device: the target device
526 */
527static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
528{
529	struct cpuidle_driver_kobj *kdrv;
530	struct cpuidle_device_kobj *kdev = dev->kobj_dev;
531	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
532	int ret;
533
534	kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
535	if (!kdrv)
536		return -ENOMEM;
537
538	kdrv->drv = drv;
539	init_completion(&kdrv->kobj_unregister);
540
541	ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
542				   &kdev->kobj, "driver");
543	if (ret) {
544		kfree(kdrv);
545		return ret;
546	}
547
548	kobject_uevent(&kdrv->kobj, KOBJ_ADD);
549	dev->kobj_driver = kdrv;
550
551	return ret;
552}
553
554/**
555 * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
556 * @device: the target device
557 */
558static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
559{
560	struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
561	kobject_put(&kdrv->kobj);
562	wait_for_completion(&kdrv->kobj_unregister);
563	kfree(kdrv);
564}
565#else
566static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
567{
568	return 0;
569}
570
571static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
572{
573	;
574}
575#endif
576
577/**
578 * cpuidle_add_device_sysfs - adds device specific sysfs attributes
579 * @device: the target device
580 */
581int cpuidle_add_device_sysfs(struct cpuidle_device *device)
582{
583	int ret;
584
585	ret = cpuidle_add_state_sysfs(device);
586	if (ret)
587		return ret;
588
589	ret = cpuidle_add_driver_sysfs(device);
590	if (ret)
591		cpuidle_remove_state_sysfs(device);
592	return ret;
593}
594
595/**
596 * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
597 * @device : the target device
598 */
599void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
600{
601	cpuidle_remove_driver_sysfs(device);
602	cpuidle_remove_state_sysfs(device);
603}
604
605/**
606 * cpuidle_add_sysfs - creates a sysfs instance for the target device
607 * @dev: the target device
608 */
609int cpuidle_add_sysfs(struct cpuidle_device *dev)
610{
611	struct cpuidle_device_kobj *kdev;
612	struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
613	int error;
614
615	kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
616	if (!kdev)
617		return -ENOMEM;
618	kdev->dev = dev;
619	dev->kobj_dev = kdev;
620
621	init_completion(&kdev->kobj_unregister);
622
623	error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
624				   "cpuidle");
625	if (error) {
626		kfree(kdev);
627		return error;
628	}
629
630	kobject_uevent(&kdev->kobj, KOBJ_ADD);
631
632	return 0;
633}
634
635/**
636 * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
637 * @dev: the target device
638 */
639void cpuidle_remove_sysfs(struct cpuidle_device *dev)
640{
641	struct cpuidle_device_kobj *kdev = dev->kobj_dev;
642
643	kobject_put(&kdev->kobj);
644	wait_for_completion(&kdev->kobj_unregister);
645	kfree(kdev);
646}
647