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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 ssize_t show_available_governors(struct device *dev,
22 struct device_attribute *attr,
23 char *buf)
24{
25 ssize_t i = 0;
26 struct cpuidle_governor *tmp;
27
28 mutex_lock(&cpuidle_lock);
29 list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
30 if (i >= (ssize_t) (PAGE_SIZE - (CPUIDLE_NAME_LEN + 2)))
31 goto out;
32
33 i += scnprintf(&buf[i], CPUIDLE_NAME_LEN + 1, "%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 device *dev,
43 struct device_attribute *attr,
44 char *buf)
45{
46 ssize_t ret;
47 struct cpuidle_driver *drv;
48
49 spin_lock(&cpuidle_driver_lock);
50 drv = cpuidle_get_driver();
51 if (drv)
52 ret = sprintf(buf, "%s\n", drv->name);
53 else
54 ret = sprintf(buf, "none\n");
55 spin_unlock(&cpuidle_driver_lock);
56
57 return ret;
58}
59
60static ssize_t show_current_governor(struct device *dev,
61 struct device_attribute *attr,
62 char *buf)
63{
64 ssize_t ret;
65
66 mutex_lock(&cpuidle_lock);
67 if (cpuidle_curr_governor)
68 ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
69 else
70 ret = sprintf(buf, "none\n");
71 mutex_unlock(&cpuidle_lock);
72
73 return ret;
74}
75
76static ssize_t store_current_governor(struct device *dev,
77 struct device_attribute *attr,
78 const char *buf, size_t count)
79{
80 char gov_name[CPUIDLE_NAME_LEN + 1];
81 int ret;
82 struct cpuidle_governor *gov;
83
84 ret = sscanf(buf, "%" __stringify(CPUIDLE_NAME_LEN) "s", gov_name);
85 if (ret != 1)
86 return -EINVAL;
87
88 mutex_lock(&cpuidle_lock);
89 ret = -EINVAL;
90 list_for_each_entry(gov, &cpuidle_governors, governor_list) {
91 if (!strncmp(gov->name, gov_name, CPUIDLE_NAME_LEN)) {
92 ret = cpuidle_switch_governor(gov);
93 break;
94 }
95 }
96 mutex_unlock(&cpuidle_lock);
97
98 return ret ? ret : count;
99}
100
101static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
102static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
103static DEVICE_ATTR(current_governor, 0644, show_current_governor,
104 store_current_governor);
105static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
106
107static struct attribute *cpuidle_attrs[] = {
108 &dev_attr_available_governors.attr,
109 &dev_attr_current_driver.attr,
110 &dev_attr_current_governor.attr,
111 &dev_attr_current_governor_ro.attr,
112 NULL
113};
114
115static struct attribute_group cpuidle_attr_group = {
116 .attrs = cpuidle_attrs,
117 .name = "cpuidle",
118};
119
120/**
121 * cpuidle_add_interface - add CPU global sysfs attributes
122 */
123int cpuidle_add_interface(void)
124{
125 struct device *dev_root = bus_get_dev_root(&cpu_subsys);
126 int retval;
127
128 if (!dev_root)
129 return -EINVAL;
130
131 retval = sysfs_create_group(&dev_root->kobj, &cpuidle_attr_group);
132 put_device(dev_root);
133 return retval;
134}
135
136/**
137 * cpuidle_remove_interface - remove CPU global sysfs attributes
138 * @dev: the target device
139 */
140void cpuidle_remove_interface(struct device *dev)
141{
142 sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
143}
144
145struct cpuidle_attr {
146 struct attribute attr;
147 ssize_t (*show)(struct cpuidle_device *, char *);
148 ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
149};
150
151#define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
152
153struct cpuidle_device_kobj {
154 struct cpuidle_device *dev;
155 struct completion kobj_unregister;
156 struct kobject kobj;
157};
158
159static inline struct cpuidle_device *to_cpuidle_device(struct kobject *kobj)
160{
161 struct cpuidle_device_kobj *kdev =
162 container_of(kobj, struct cpuidle_device_kobj, kobj);
163
164 return kdev->dev;
165}
166
167static ssize_t cpuidle_show(struct kobject *kobj, struct attribute *attr,
168 char *buf)
169{
170 int ret = -EIO;
171 struct cpuidle_device *dev = to_cpuidle_device(kobj);
172 struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
173
174 if (cattr->show) {
175 mutex_lock(&cpuidle_lock);
176 ret = cattr->show(dev, buf);
177 mutex_unlock(&cpuidle_lock);
178 }
179 return ret;
180}
181
182static ssize_t cpuidle_store(struct kobject *kobj, struct attribute *attr,
183 const char *buf, size_t count)
184{
185 int ret = -EIO;
186 struct cpuidle_device *dev = to_cpuidle_device(kobj);
187 struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
188
189 if (cattr->store) {
190 mutex_lock(&cpuidle_lock);
191 ret = cattr->store(dev, buf, count);
192 mutex_unlock(&cpuidle_lock);
193 }
194 return ret;
195}
196
197static const struct sysfs_ops cpuidle_sysfs_ops = {
198 .show = cpuidle_show,
199 .store = cpuidle_store,
200};
201
202static void cpuidle_sysfs_release(struct kobject *kobj)
203{
204 struct cpuidle_device_kobj *kdev =
205 container_of(kobj, struct cpuidle_device_kobj, kobj);
206
207 complete(&kdev->kobj_unregister);
208}
209
210static const struct kobj_type ktype_cpuidle = {
211 .sysfs_ops = &cpuidle_sysfs_ops,
212 .release = cpuidle_sysfs_release,
213};
214
215struct cpuidle_state_attr {
216 struct attribute attr;
217 ssize_t (*show)(struct cpuidle_state *, \
218 struct cpuidle_state_usage *, char *);
219 ssize_t (*store)(struct cpuidle_state *, \
220 struct cpuidle_state_usage *, const char *, size_t);
221};
222
223#define define_one_state_ro(_name, show) \
224static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
225
226#define define_one_state_rw(_name, show, store) \
227static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
228
229#define define_show_state_function(_name) \
230static ssize_t show_state_##_name(struct cpuidle_state *state, \
231 struct cpuidle_state_usage *state_usage, char *buf) \
232{ \
233 return sprintf(buf, "%u\n", state->_name);\
234}
235
236#define define_show_state_ull_function(_name) \
237static ssize_t show_state_##_name(struct cpuidle_state *state, \
238 struct cpuidle_state_usage *state_usage, \
239 char *buf) \
240{ \
241 return sprintf(buf, "%llu\n", state_usage->_name);\
242}
243
244#define define_show_state_str_function(_name) \
245static ssize_t show_state_##_name(struct cpuidle_state *state, \
246 struct cpuidle_state_usage *state_usage, \
247 char *buf) \
248{ \
249 if (state->_name[0] == '\0')\
250 return sprintf(buf, "<null>\n");\
251 return sprintf(buf, "%s\n", state->_name);\
252}
253
254#define define_show_state_time_function(_name) \
255static ssize_t show_state_##_name(struct cpuidle_state *state, \
256 struct cpuidle_state_usage *state_usage, \
257 char *buf) \
258{ \
259 return sprintf(buf, "%llu\n", ktime_to_us(state->_name##_ns)); \
260}
261
262define_show_state_time_function(exit_latency)
263define_show_state_time_function(target_residency)
264define_show_state_function(power_usage)
265define_show_state_ull_function(usage)
266define_show_state_ull_function(rejected)
267define_show_state_str_function(name)
268define_show_state_str_function(desc)
269define_show_state_ull_function(above)
270define_show_state_ull_function(below)
271
272static ssize_t show_state_time(struct cpuidle_state *state,
273 struct cpuidle_state_usage *state_usage,
274 char *buf)
275{
276 return sprintf(buf, "%llu\n", ktime_to_us(state_usage->time_ns));
277}
278
279static ssize_t show_state_disable(struct cpuidle_state *state,
280 struct cpuidle_state_usage *state_usage,
281 char *buf)
282{
283 return sprintf(buf, "%llu\n",
284 state_usage->disable & CPUIDLE_STATE_DISABLED_BY_USER);
285}
286
287static ssize_t store_state_disable(struct cpuidle_state *state,
288 struct cpuidle_state_usage *state_usage,
289 const char *buf, size_t size)
290{
291 unsigned int value;
292 int err;
293
294 if (!capable(CAP_SYS_ADMIN))
295 return -EPERM;
296
297 err = kstrtouint(buf, 0, &value);
298 if (err)
299 return err;
300
301 if (value)
302 state_usage->disable |= CPUIDLE_STATE_DISABLED_BY_USER;
303 else
304 state_usage->disable &= ~CPUIDLE_STATE_DISABLED_BY_USER;
305
306 return size;
307}
308
309static ssize_t show_state_default_status(struct cpuidle_state *state,
310 struct cpuidle_state_usage *state_usage,
311 char *buf)
312{
313 return sprintf(buf, "%s\n",
314 state->flags & CPUIDLE_FLAG_OFF ? "disabled" : "enabled");
315}
316
317define_one_state_ro(name, show_state_name);
318define_one_state_ro(desc, show_state_desc);
319define_one_state_ro(latency, show_state_exit_latency);
320define_one_state_ro(residency, show_state_target_residency);
321define_one_state_ro(power, show_state_power_usage);
322define_one_state_ro(usage, show_state_usage);
323define_one_state_ro(rejected, show_state_rejected);
324define_one_state_ro(time, show_state_time);
325define_one_state_rw(disable, show_state_disable, store_state_disable);
326define_one_state_ro(above, show_state_above);
327define_one_state_ro(below, show_state_below);
328define_one_state_ro(default_status, show_state_default_status);
329
330static struct attribute *cpuidle_state_default_attrs[] = {
331 &attr_name.attr,
332 &attr_desc.attr,
333 &attr_latency.attr,
334 &attr_residency.attr,
335 &attr_power.attr,
336 &attr_usage.attr,
337 &attr_rejected.attr,
338 &attr_time.attr,
339 &attr_disable.attr,
340 &attr_above.attr,
341 &attr_below.attr,
342 &attr_default_status.attr,
343 NULL
344};
345ATTRIBUTE_GROUPS(cpuidle_state_default);
346
347struct cpuidle_state_kobj {
348 struct cpuidle_state *state;
349 struct cpuidle_state_usage *state_usage;
350 struct completion kobj_unregister;
351 struct kobject kobj;
352 struct cpuidle_device *device;
353};
354
355#ifdef CONFIG_SUSPEND
356#define define_show_state_s2idle_ull_function(_name) \
357static ssize_t show_state_s2idle_##_name(struct cpuidle_state *state, \
358 struct cpuidle_state_usage *state_usage, \
359 char *buf) \
360{ \
361 return sprintf(buf, "%llu\n", state_usage->s2idle_##_name);\
362}
363
364define_show_state_s2idle_ull_function(usage);
365define_show_state_s2idle_ull_function(time);
366
367#define define_one_state_s2idle_ro(_name, show) \
368static struct cpuidle_state_attr attr_s2idle_##_name = \
369 __ATTR(_name, 0444, show, NULL)
370
371define_one_state_s2idle_ro(usage, show_state_s2idle_usage);
372define_one_state_s2idle_ro(time, show_state_s2idle_time);
373
374static struct attribute *cpuidle_state_s2idle_attrs[] = {
375 &attr_s2idle_usage.attr,
376 &attr_s2idle_time.attr,
377 NULL
378};
379
380static const struct attribute_group cpuidle_state_s2idle_group = {
381 .name = "s2idle",
382 .attrs = cpuidle_state_s2idle_attrs,
383};
384
385static void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
386{
387 int ret;
388
389 if (!kobj->state->enter_s2idle)
390 return;
391
392 ret = sysfs_create_group(&kobj->kobj, &cpuidle_state_s2idle_group);
393 if (ret)
394 pr_debug("%s: sysfs attribute group not created\n", __func__);
395}
396
397static void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
398{
399 if (kobj->state->enter_s2idle)
400 sysfs_remove_group(&kobj->kobj, &cpuidle_state_s2idle_group);
401}
402#else
403static inline void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
404static inline void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
405#endif /* CONFIG_SUSPEND */
406
407#define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
408#define kobj_to_state(k) (kobj_to_state_obj(k)->state)
409#define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
410#define kobj_to_device(k) (kobj_to_state_obj(k)->device)
411#define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
412
413static ssize_t cpuidle_state_show(struct kobject *kobj, struct attribute *attr,
414 char *buf)
415{
416 int ret = -EIO;
417 struct cpuidle_state *state = kobj_to_state(kobj);
418 struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
419 struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
420
421 if (cattr->show)
422 ret = cattr->show(state, state_usage, buf);
423
424 return ret;
425}
426
427static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr,
428 const char *buf, size_t size)
429{
430 int ret = -EIO;
431 struct cpuidle_state *state = kobj_to_state(kobj);
432 struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
433 struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
434 struct cpuidle_device *dev = kobj_to_device(kobj);
435
436 if (cattr->store)
437 ret = cattr->store(state, state_usage, buf, size);
438
439 /* reset poll time cache */
440 dev->poll_limit_ns = 0;
441
442 return ret;
443}
444
445static const struct sysfs_ops cpuidle_state_sysfs_ops = {
446 .show = cpuidle_state_show,
447 .store = cpuidle_state_store,
448};
449
450static void cpuidle_state_sysfs_release(struct kobject *kobj)
451{
452 struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
453
454 complete(&state_obj->kobj_unregister);
455}
456
457static const struct kobj_type ktype_state_cpuidle = {
458 .sysfs_ops = &cpuidle_state_sysfs_ops,
459 .default_groups = cpuidle_state_default_groups,
460 .release = cpuidle_state_sysfs_release,
461};
462
463static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
464{
465 cpuidle_remove_s2idle_attr_group(device->kobjs[i]);
466 kobject_put(&device->kobjs[i]->kobj);
467 wait_for_completion(&device->kobjs[i]->kobj_unregister);
468 kfree(device->kobjs[i]);
469 device->kobjs[i] = NULL;
470}
471
472/**
473 * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes
474 * @device: the target device
475 */
476static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
477{
478 int i, ret = -ENOMEM;
479 struct cpuidle_state_kobj *kobj;
480 struct cpuidle_device_kobj *kdev = device->kobj_dev;
481 struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
482
483 /* state statistics */
484 for (i = 0; i < drv->state_count; i++) {
485 kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
486 if (!kobj) {
487 ret = -ENOMEM;
488 goto error_state;
489 }
490 kobj->state = &drv->states[i];
491 kobj->state_usage = &device->states_usage[i];
492 kobj->device = device;
493 init_completion(&kobj->kobj_unregister);
494
495 ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
496 &kdev->kobj, "state%d", i);
497 if (ret) {
498 kobject_put(&kobj->kobj);
499 kfree(kobj);
500 goto error_state;
501 }
502 cpuidle_add_s2idle_attr_group(kobj);
503 kobject_uevent(&kobj->kobj, KOBJ_ADD);
504 device->kobjs[i] = kobj;
505 }
506
507 return 0;
508
509error_state:
510 for (i = i - 1; i >= 0; i--)
511 cpuidle_free_state_kobj(device, i);
512 return ret;
513}
514
515/**
516 * cpuidle_remove_state_sysfs - removes the cpuidle states sysfs attributes
517 * @device: the target device
518 */
519static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
520{
521 struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
522 int i;
523
524 for (i = 0; i < drv->state_count; i++)
525 cpuidle_free_state_kobj(device, i);
526}
527
528#ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
529#define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
530#define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
531
532#define define_one_driver_ro(_name, show) \
533 static struct cpuidle_driver_attr attr_driver_##_name = \
534 __ATTR(_name, 0444, show, NULL)
535
536struct cpuidle_driver_kobj {
537 struct cpuidle_driver *drv;
538 struct completion kobj_unregister;
539 struct kobject kobj;
540};
541
542struct cpuidle_driver_attr {
543 struct attribute attr;
544 ssize_t (*show)(struct cpuidle_driver *, char *);
545 ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
546};
547
548static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
549{
550 ssize_t ret;
551
552 spin_lock(&cpuidle_driver_lock);
553 ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
554 spin_unlock(&cpuidle_driver_lock);
555
556 return ret;
557}
558
559static void cpuidle_driver_sysfs_release(struct kobject *kobj)
560{
561 struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
562 complete(&driver_kobj->kobj_unregister);
563}
564
565static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
566 char *buf)
567{
568 int ret = -EIO;
569 struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
570 struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
571
572 if (dattr->show)
573 ret = dattr->show(driver_kobj->drv, buf);
574
575 return ret;
576}
577
578static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
579 const char *buf, size_t size)
580{
581 int ret = -EIO;
582 struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
583 struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
584
585 if (dattr->store)
586 ret = dattr->store(driver_kobj->drv, buf, size);
587
588 return ret;
589}
590
591define_one_driver_ro(name, show_driver_name);
592
593static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
594 .show = cpuidle_driver_show,
595 .store = cpuidle_driver_store,
596};
597
598static struct attribute *cpuidle_driver_default_attrs[] = {
599 &attr_driver_name.attr,
600 NULL
601};
602ATTRIBUTE_GROUPS(cpuidle_driver_default);
603
604static const struct kobj_type ktype_driver_cpuidle = {
605 .sysfs_ops = &cpuidle_driver_sysfs_ops,
606 .default_groups = cpuidle_driver_default_groups,
607 .release = cpuidle_driver_sysfs_release,
608};
609
610/**
611 * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
612 * @dev: the target device
613 */
614static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
615{
616 struct cpuidle_driver_kobj *kdrv;
617 struct cpuidle_device_kobj *kdev = dev->kobj_dev;
618 struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
619 int ret;
620
621 kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
622 if (!kdrv)
623 return -ENOMEM;
624
625 kdrv->drv = drv;
626 init_completion(&kdrv->kobj_unregister);
627
628 ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
629 &kdev->kobj, "driver");
630 if (ret) {
631 kobject_put(&kdrv->kobj);
632 kfree(kdrv);
633 return ret;
634 }
635
636 kobject_uevent(&kdrv->kobj, KOBJ_ADD);
637 dev->kobj_driver = kdrv;
638
639 return ret;
640}
641
642/**
643 * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
644 * @dev: the target device
645 */
646static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
647{
648 struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
649 kobject_put(&kdrv->kobj);
650 wait_for_completion(&kdrv->kobj_unregister);
651 kfree(kdrv);
652}
653#else
654static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
655{
656 return 0;
657}
658
659static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
660{
661 ;
662}
663#endif
664
665/**
666 * cpuidle_add_device_sysfs - adds device specific sysfs attributes
667 * @device: the target device
668 */
669int cpuidle_add_device_sysfs(struct cpuidle_device *device)
670{
671 int ret;
672
673 ret = cpuidle_add_state_sysfs(device);
674 if (ret)
675 return ret;
676
677 ret = cpuidle_add_driver_sysfs(device);
678 if (ret)
679 cpuidle_remove_state_sysfs(device);
680 return ret;
681}
682
683/**
684 * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
685 * @device : the target device
686 */
687void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
688{
689 cpuidle_remove_driver_sysfs(device);
690 cpuidle_remove_state_sysfs(device);
691}
692
693/**
694 * cpuidle_add_sysfs - creates a sysfs instance for the target device
695 * @dev: the target device
696 */
697int cpuidle_add_sysfs(struct cpuidle_device *dev)
698{
699 struct cpuidle_device_kobj *kdev;
700 struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
701 int error;
702
703 /*
704 * Return if cpu_device is not setup for this CPU.
705 *
706 * This could happen if the arch did not set up cpu_device
707 * since this CPU is not in cpu_present mask and the
708 * driver did not send a correct CPU mask during registration.
709 * Without this check we would end up passing bogus
710 * value for &cpu_dev->kobj in kobject_init_and_add()
711 */
712 if (!cpu_dev)
713 return -ENODEV;
714
715 kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
716 if (!kdev)
717 return -ENOMEM;
718 kdev->dev = dev;
719
720 init_completion(&kdev->kobj_unregister);
721
722 error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
723 "cpuidle");
724 if (error) {
725 kobject_put(&kdev->kobj);
726 kfree(kdev);
727 return error;
728 }
729
730 dev->kobj_dev = kdev;
731 kobject_uevent(&kdev->kobj, KOBJ_ADD);
732
733 return 0;
734}
735
736/**
737 * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
738 * @dev: the target device
739 */
740void cpuidle_remove_sysfs(struct cpuidle_device *dev)
741{
742 struct cpuidle_device_kobj *kdev = dev->kobj_dev;
743
744 kobject_put(&kdev->kobj);
745 wait_for_completion(&kdev->kobj_unregister);
746 kfree(kdev);
747}
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/capability.h>
15
16#include "cpuidle.h"
17
18static unsigned int sysfs_switch;
19static int __init cpuidle_sysfs_setup(char *unused)
20{
21 sysfs_switch = 1;
22 return 1;
23}
24__setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);
25
26static ssize_t show_available_governors(struct device *dev,
27 struct device_attribute *attr,
28 char *buf)
29{
30 ssize_t i = 0;
31 struct cpuidle_governor *tmp;
32
33 mutex_lock(&cpuidle_lock);
34 list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
35 if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) - CPUIDLE_NAME_LEN - 2))
36 goto out;
37 i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
38 }
39
40out:
41 i+= sprintf(&buf[i], "\n");
42 mutex_unlock(&cpuidle_lock);
43 return i;
44}
45
46static ssize_t show_current_driver(struct device *dev,
47 struct device_attribute *attr,
48 char *buf)
49{
50 ssize_t ret;
51 struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
52
53 spin_lock(&cpuidle_driver_lock);
54 if (cpuidle_driver)
55 ret = sprintf(buf, "%s\n", cpuidle_driver->name);
56 else
57 ret = sprintf(buf, "none\n");
58 spin_unlock(&cpuidle_driver_lock);
59
60 return ret;
61}
62
63static ssize_t show_current_governor(struct device *dev,
64 struct device_attribute *attr,
65 char *buf)
66{
67 ssize_t ret;
68
69 mutex_lock(&cpuidle_lock);
70 if (cpuidle_curr_governor)
71 ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
72 else
73 ret = sprintf(buf, "none\n");
74 mutex_unlock(&cpuidle_lock);
75
76 return ret;
77}
78
79static ssize_t store_current_governor(struct device *dev,
80 struct device_attribute *attr,
81 const char *buf, size_t count)
82{
83 char gov_name[CPUIDLE_NAME_LEN];
84 int ret = -EINVAL;
85 size_t len = count;
86 struct cpuidle_governor *gov;
87
88 if (!len || len >= sizeof(gov_name))
89 return -EINVAL;
90
91 memcpy(gov_name, buf, len);
92 gov_name[len] = '\0';
93 if (gov_name[len - 1] == '\n')
94 gov_name[--len] = '\0';
95
96 mutex_lock(&cpuidle_lock);
97
98 list_for_each_entry(gov, &cpuidle_governors, governor_list) {
99 if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
100 ret = cpuidle_switch_governor(gov);
101 break;
102 }
103 }
104
105 mutex_unlock(&cpuidle_lock);
106
107 if (ret)
108 return ret;
109 else
110 return count;
111}
112
113static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
114static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
115
116static struct attribute *cpuidle_default_attrs[] = {
117 &dev_attr_current_driver.attr,
118 &dev_attr_current_governor_ro.attr,
119 NULL
120};
121
122static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
123static DEVICE_ATTR(current_governor, 0644, show_current_governor,
124 store_current_governor);
125
126static struct attribute *cpuidle_switch_attrs[] = {
127 &dev_attr_available_governors.attr,
128 &dev_attr_current_driver.attr,
129 &dev_attr_current_governor.attr,
130 NULL
131};
132
133static struct attribute_group cpuidle_attr_group = {
134 .attrs = cpuidle_default_attrs,
135 .name = "cpuidle",
136};
137
138/**
139 * cpuidle_add_interface - add CPU global sysfs attributes
140 */
141int cpuidle_add_interface(struct device *dev)
142{
143 if (sysfs_switch)
144 cpuidle_attr_group.attrs = cpuidle_switch_attrs;
145
146 return sysfs_create_group(&dev->kobj, &cpuidle_attr_group);
147}
148
149/**
150 * cpuidle_remove_interface - remove CPU global sysfs attributes
151 */
152void cpuidle_remove_interface(struct device *dev)
153{
154 sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
155}
156
157struct cpuidle_attr {
158 struct attribute attr;
159 ssize_t (*show)(struct cpuidle_device *, char *);
160 ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
161};
162
163#define define_one_ro(_name, show) \
164 static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
165#define define_one_rw(_name, show, store) \
166 static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
167
168#define kobj_to_cpuidledev(k) container_of(k, struct cpuidle_device, kobj)
169#define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
170static ssize_t cpuidle_show(struct kobject * kobj, struct attribute * attr ,char * buf)
171{
172 int ret = -EIO;
173 struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
174 struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
175
176 if (cattr->show) {
177 mutex_lock(&cpuidle_lock);
178 ret = cattr->show(dev, buf);
179 mutex_unlock(&cpuidle_lock);
180 }
181 return ret;
182}
183
184static ssize_t cpuidle_store(struct kobject * kobj, struct attribute * attr,
185 const char * buf, size_t count)
186{
187 int ret = -EIO;
188 struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
189 struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
190
191 if (cattr->store) {
192 mutex_lock(&cpuidle_lock);
193 ret = cattr->store(dev, buf, count);
194 mutex_unlock(&cpuidle_lock);
195 }
196 return ret;
197}
198
199static const struct sysfs_ops cpuidle_sysfs_ops = {
200 .show = cpuidle_show,
201 .store = cpuidle_store,
202};
203
204static void cpuidle_sysfs_release(struct kobject *kobj)
205{
206 struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
207
208 complete(&dev->kobj_unregister);
209}
210
211static struct kobj_type ktype_cpuidle = {
212 .sysfs_ops = &cpuidle_sysfs_ops,
213 .release = cpuidle_sysfs_release,
214};
215
216struct cpuidle_state_attr {
217 struct attribute attr;
218 ssize_t (*show)(struct cpuidle_state *, \
219 struct cpuidle_state_usage *, char *);
220 ssize_t (*store)(struct cpuidle_state *, const char *, size_t);
221};
222
223#define define_one_state_ro(_name, show) \
224static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
225
226#define define_one_state_rw(_name, show, store) \
227static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
228
229#define define_show_state_function(_name) \
230static ssize_t show_state_##_name(struct cpuidle_state *state, \
231 struct cpuidle_state_usage *state_usage, char *buf) \
232{ \
233 return sprintf(buf, "%u\n", state->_name);\
234}
235
236#define define_store_state_function(_name) \
237static ssize_t store_state_##_name(struct cpuidle_state *state, \
238 const char *buf, size_t size) \
239{ \
240 long value; \
241 int err; \
242 if (!capable(CAP_SYS_ADMIN)) \
243 return -EPERM; \
244 err = kstrtol(buf, 0, &value); \
245 if (err) \
246 return err; \
247 if (value) \
248 state->disable = 1; \
249 else \
250 state->disable = 0; \
251 return size; \
252}
253
254#define define_show_state_ull_function(_name) \
255static ssize_t show_state_##_name(struct cpuidle_state *state, \
256 struct cpuidle_state_usage *state_usage, char *buf) \
257{ \
258 return sprintf(buf, "%llu\n", state_usage->_name);\
259}
260
261#define define_show_state_str_function(_name) \
262static ssize_t show_state_##_name(struct cpuidle_state *state, \
263 struct cpuidle_state_usage *state_usage, char *buf) \
264{ \
265 if (state->_name[0] == '\0')\
266 return sprintf(buf, "<null>\n");\
267 return sprintf(buf, "%s\n", state->_name);\
268}
269
270define_show_state_function(exit_latency)
271define_show_state_function(power_usage)
272define_show_state_ull_function(usage)
273define_show_state_ull_function(time)
274define_show_state_str_function(name)
275define_show_state_str_function(desc)
276define_show_state_function(disable)
277define_store_state_function(disable)
278
279define_one_state_ro(name, show_state_name);
280define_one_state_ro(desc, show_state_desc);
281define_one_state_ro(latency, show_state_exit_latency);
282define_one_state_ro(power, show_state_power_usage);
283define_one_state_ro(usage, show_state_usage);
284define_one_state_ro(time, show_state_time);
285define_one_state_rw(disable, show_state_disable, store_state_disable);
286
287static struct attribute *cpuidle_state_default_attrs[] = {
288 &attr_name.attr,
289 &attr_desc.attr,
290 &attr_latency.attr,
291 &attr_power.attr,
292 &attr_usage.attr,
293 &attr_time.attr,
294 &attr_disable.attr,
295 NULL
296};
297
298#define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
299#define kobj_to_state(k) (kobj_to_state_obj(k)->state)
300#define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
301#define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
302static ssize_t cpuidle_state_show(struct kobject * kobj,
303 struct attribute * attr ,char * buf)
304{
305 int ret = -EIO;
306 struct cpuidle_state *state = kobj_to_state(kobj);
307 struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
308 struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
309
310 if (cattr->show)
311 ret = cattr->show(state, state_usage, buf);
312
313 return ret;
314}
315
316static ssize_t cpuidle_state_store(struct kobject *kobj,
317 struct attribute *attr, const char *buf, size_t size)
318{
319 int ret = -EIO;
320 struct cpuidle_state *state = kobj_to_state(kobj);
321 struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
322
323 if (cattr->store)
324 ret = cattr->store(state, buf, size);
325
326 return ret;
327}
328
329static const struct sysfs_ops cpuidle_state_sysfs_ops = {
330 .show = cpuidle_state_show,
331 .store = cpuidle_state_store,
332};
333
334static void cpuidle_state_sysfs_release(struct kobject *kobj)
335{
336 struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
337
338 complete(&state_obj->kobj_unregister);
339}
340
341static struct kobj_type ktype_state_cpuidle = {
342 .sysfs_ops = &cpuidle_state_sysfs_ops,
343 .default_attrs = cpuidle_state_default_attrs,
344 .release = cpuidle_state_sysfs_release,
345};
346
347static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
348{
349 kobject_put(&device->kobjs[i]->kobj);
350 wait_for_completion(&device->kobjs[i]->kobj_unregister);
351 kfree(device->kobjs[i]);
352 device->kobjs[i] = NULL;
353}
354
355/**
356 * cpuidle_add_driver_sysfs - adds driver-specific sysfs attributes
357 * @device: the target device
358 */
359int cpuidle_add_state_sysfs(struct cpuidle_device *device)
360{
361 int i, ret = -ENOMEM;
362 struct cpuidle_state_kobj *kobj;
363 struct cpuidle_driver *drv = cpuidle_get_driver();
364
365 /* state statistics */
366 for (i = 0; i < device->state_count; i++) {
367 kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
368 if (!kobj)
369 goto error_state;
370 kobj->state = &drv->states[i];
371 kobj->state_usage = &device->states_usage[i];
372 init_completion(&kobj->kobj_unregister);
373
374 ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle, &device->kobj,
375 "state%d", i);
376 if (ret) {
377 kfree(kobj);
378 goto error_state;
379 }
380 kobject_uevent(&kobj->kobj, KOBJ_ADD);
381 device->kobjs[i] = kobj;
382 }
383
384 return 0;
385
386error_state:
387 for (i = i - 1; i >= 0; i--)
388 cpuidle_free_state_kobj(device, i);
389 return ret;
390}
391
392/**
393 * cpuidle_remove_driver_sysfs - removes driver-specific sysfs attributes
394 * @device: the target device
395 */
396void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
397{
398 int i;
399
400 for (i = 0; i < device->state_count; i++)
401 cpuidle_free_state_kobj(device, i);
402}
403
404/**
405 * cpuidle_add_sysfs - creates a sysfs instance for the target device
406 * @dev: the target device
407 */
408int cpuidle_add_sysfs(struct device *cpu_dev)
409{
410 int cpu = cpu_dev->id;
411 struct cpuidle_device *dev;
412 int error;
413
414 dev = per_cpu(cpuidle_devices, cpu);
415 error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
416 "cpuidle");
417 if (!error)
418 kobject_uevent(&dev->kobj, KOBJ_ADD);
419 return error;
420}
421
422/**
423 * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
424 * @dev: the target device
425 */
426void cpuidle_remove_sysfs(struct device *cpu_dev)
427{
428 int cpu = cpu_dev->id;
429 struct cpuidle_device *dev;
430
431 dev = per_cpu(cpuidle_devices, cpu);
432 kobject_put(&dev->kobj);
433}