GNU Linux-libre 4.4.289-gnu1
[releases.git] / drivers / cpuidle / sysfs.c
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
21 static unsigned int sysfs_switch;
22 static 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
29 static 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
44 out:
45         i+= sprintf(&buf[i], "\n");
46         mutex_unlock(&cpuidle_lock);
47         return i;
48 }
49
50 static 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
68 static 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
84 static 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
118 static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
119 static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
120
121 static struct attribute *cpuidle_default_attrs[] = {
122         &dev_attr_current_driver.attr,
123         &dev_attr_current_governor_ro.attr,
124         NULL
125 };
126
127 static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
128 static DEVICE_ATTR(current_governor, 0644, show_current_governor,
129                    store_current_governor);
130
131 static 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
138 static 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  */
146 int 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  */
157 void cpuidle_remove_interface(struct device *dev)
158 {
159         sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
160 }
161
162 struct 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
175 struct cpuidle_device_kobj {
176         struct cpuidle_device *dev;
177         struct completion kobj_unregister;
178         struct kobject kobj;
179 };
180
181 static 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
189 static 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
204 static 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
219 static const struct sysfs_ops cpuidle_sysfs_ops = {
220         .show = cpuidle_show,
221         .store = cpuidle_store,
222 };
223
224 static 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
232 static struct kobj_type ktype_cpuidle = {
233         .sysfs_ops = &cpuidle_sysfs_ops,
234         .release = cpuidle_sysfs_release,
235 };
236
237 struct 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) \
246 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
247
248 #define define_one_state_rw(_name, show, store) \
249 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
250
251 #define define_show_state_function(_name) \
252 static 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) \
259 static 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) \
278 static 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) \
286 static 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
295 define_show_state_function(exit_latency)
296 define_show_state_function(target_residency)
297 define_show_state_function(power_usage)
298 define_show_state_ull_function(usage)
299 define_show_state_ull_function(time)
300 define_show_state_str_function(name)
301 define_show_state_str_function(desc)
302 define_show_state_ull_function(disable)
303 define_store_state_ull_function(disable)
304
305 define_one_state_ro(name, show_state_name);
306 define_one_state_ro(desc, show_state_desc);
307 define_one_state_ro(latency, show_state_exit_latency);
308 define_one_state_ro(residency, show_state_target_residency);
309 define_one_state_ro(power, show_state_power_usage);
310 define_one_state_ro(usage, show_state_usage);
311 define_one_state_ro(time, show_state_time);
312 define_one_state_rw(disable, show_state_disable, store_state_disable);
313
314 static 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
326 struct 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
338 static 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
352 static 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
366 static const struct sysfs_ops cpuidle_state_sysfs_ops = {
367         .show = cpuidle_state_show,
368         .store = cpuidle_state_store,
369 };
370
371 static 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
378 static 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
384 static 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  */
396 static 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 < drv->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                         kobject_put(&kobj->kobj);
416                         goto error_state;
417                 }
418                 kobject_uevent(&kobj->kobj, KOBJ_ADD);
419                 device->kobjs[i] = kobj;
420         }
421
422         return 0;
423
424 error_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  */
434 static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
435 {
436         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
437         int i;
438
439         for (i = 0; i < drv->state_count; i++)
440                 cpuidle_free_state_kobj(device, i);
441 }
442
443 #ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
444 #define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
445 #define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
446
447 #define define_one_driver_ro(_name, show)                       \
448         static struct cpuidle_driver_attr attr_driver_##_name = \
449                 __ATTR(_name, 0444, show, NULL)
450
451 struct cpuidle_driver_kobj {
452         struct cpuidle_driver *drv;
453         struct completion kobj_unregister;
454         struct kobject kobj;
455 };
456
457 struct cpuidle_driver_attr {
458         struct attribute attr;
459         ssize_t (*show)(struct cpuidle_driver *, char *);
460         ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
461 };
462
463 static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
464 {
465         ssize_t ret;
466
467         spin_lock(&cpuidle_driver_lock);
468         ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
469         spin_unlock(&cpuidle_driver_lock);
470
471         return ret;
472 }
473
474 static void cpuidle_driver_sysfs_release(struct kobject *kobj)
475 {
476         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
477         complete(&driver_kobj->kobj_unregister);
478 }
479
480 static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
481                                    char *buf)
482 {
483         int ret = -EIO;
484         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
485         struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
486
487         if (dattr->show)
488                 ret = dattr->show(driver_kobj->drv, buf);
489
490         return ret;
491 }
492
493 static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
494                                     const char *buf, size_t size)
495 {
496         int ret = -EIO;
497         struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
498         struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
499
500         if (dattr->store)
501                 ret = dattr->store(driver_kobj->drv, buf, size);
502
503         return ret;
504 }
505
506 define_one_driver_ro(name, show_driver_name);
507
508 static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
509         .show = cpuidle_driver_show,
510         .store = cpuidle_driver_store,
511 };
512
513 static struct attribute *cpuidle_driver_default_attrs[] = {
514         &attr_driver_name.attr,
515         NULL
516 };
517
518 static struct kobj_type ktype_driver_cpuidle = {
519         .sysfs_ops = &cpuidle_driver_sysfs_ops,
520         .default_attrs = cpuidle_driver_default_attrs,
521         .release = cpuidle_driver_sysfs_release,
522 };
523
524 /**
525  * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
526  * @device: the target device
527  */
528 static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
529 {
530         struct cpuidle_driver_kobj *kdrv;
531         struct cpuidle_device_kobj *kdev = dev->kobj_dev;
532         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
533         int ret;
534
535         kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
536         if (!kdrv)
537                 return -ENOMEM;
538
539         kdrv->drv = drv;
540         init_completion(&kdrv->kobj_unregister);
541
542         ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
543                                    &kdev->kobj, "driver");
544         if (ret) {
545                 kobject_put(&kdrv->kobj);
546                 return ret;
547         }
548
549         kobject_uevent(&kdrv->kobj, KOBJ_ADD);
550         dev->kobj_driver = kdrv;
551
552         return ret;
553 }
554
555 /**
556  * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
557  * @device: the target device
558  */
559 static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
560 {
561         struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
562         kobject_put(&kdrv->kobj);
563         wait_for_completion(&kdrv->kobj_unregister);
564         kfree(kdrv);
565 }
566 #else
567 static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
568 {
569         return 0;
570 }
571
572 static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
573 {
574         ;
575 }
576 #endif
577
578 /**
579  * cpuidle_add_device_sysfs - adds device specific sysfs attributes
580  * @device: the target device
581  */
582 int cpuidle_add_device_sysfs(struct cpuidle_device *device)
583 {
584         int ret;
585
586         ret = cpuidle_add_state_sysfs(device);
587         if (ret)
588                 return ret;
589
590         ret = cpuidle_add_driver_sysfs(device);
591         if (ret)
592                 cpuidle_remove_state_sysfs(device);
593         return ret;
594 }
595
596 /**
597  * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
598  * @device : the target device
599  */
600 void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
601 {
602         cpuidle_remove_driver_sysfs(device);
603         cpuidle_remove_state_sysfs(device);
604 }
605
606 /**
607  * cpuidle_add_sysfs - creates a sysfs instance for the target device
608  * @dev: the target device
609  */
610 int cpuidle_add_sysfs(struct cpuidle_device *dev)
611 {
612         struct cpuidle_device_kobj *kdev;
613         struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
614         int error;
615
616         /*
617          * Return if cpu_device is not setup for this CPU.
618          *
619          * This could happen if the arch did not set up cpu_device
620          * since this CPU is not in cpu_present mask and the
621          * driver did not send a correct CPU mask during registration.
622          * Without this check we would end up passing bogus
623          * value for &cpu_dev->kobj in kobject_init_and_add()
624          */
625         if (!cpu_dev)
626                 return -ENODEV;
627
628         kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
629         if (!kdev)
630                 return -ENOMEM;
631         kdev->dev = dev;
632         dev->kobj_dev = kdev;
633
634         init_completion(&kdev->kobj_unregister);
635
636         error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
637                                    "cpuidle");
638         if (error) {
639                 kobject_put(&kdev->kobj);
640                 return error;
641         }
642
643         kobject_uevent(&kdev->kobj, KOBJ_ADD);
644
645         return 0;
646 }
647
648 /**
649  * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
650  * @dev: the target device
651  */
652 void cpuidle_remove_sysfs(struct cpuidle_device *dev)
653 {
654         struct cpuidle_device_kobj *kdev = dev->kobj_dev;
655
656         kobject_put(&kdev->kobj);
657         wait_for_completion(&kdev->kobj_unregister);
658         kfree(kdev);
659 }