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8#include <stdio.h>
9#include <errno.h>
10#include <stdlib.h>
11#include <string.h>
12#include <sys/types.h>
13#include <sys/stat.h>
14#include <fcntl.h>
15#include <unistd.h>
16
17#include "cpufreq.h"
18#include "cpupower_intern.h"
19
20
21
22
23
24static unsigned int sysfs_cpufreq_read_file(unsigned int cpu, const char *fname,
25 char *buf, size_t buflen)
26{
27 char path[SYSFS_PATH_MAX];
28
29 snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/cpufreq/%s",
30 cpu, fname);
31 return sysfs_read_file(path, buf, buflen);
32}
33
34
35
36static unsigned int sysfs_cpufreq_write_file(unsigned int cpu,
37 const char *fname,
38 const char *value, size_t len)
39{
40 char path[SYSFS_PATH_MAX];
41 int fd;
42 ssize_t numwrite;
43
44 snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/cpufreq/%s",
45 cpu, fname);
46
47 fd = open(path, O_WRONLY);
48 if (fd == -1)
49 return 0;
50
51 numwrite = write(fd, value, len);
52 if (numwrite < 1) {
53 close(fd);
54 return 0;
55 }
56
57 close(fd);
58
59 return (unsigned int) numwrite;
60}
61
62
63
64enum cpufreq_value {
65 CPUINFO_CUR_FREQ,
66 CPUINFO_MIN_FREQ,
67 CPUINFO_MAX_FREQ,
68 CPUINFO_LATENCY,
69 SCALING_CUR_FREQ,
70 SCALING_MIN_FREQ,
71 SCALING_MAX_FREQ,
72 STATS_NUM_TRANSITIONS,
73 MAX_CPUFREQ_VALUE_READ_FILES
74};
75
76static const char *cpufreq_value_files[MAX_CPUFREQ_VALUE_READ_FILES] = {
77 [CPUINFO_CUR_FREQ] = "cpuinfo_cur_freq",
78 [CPUINFO_MIN_FREQ] = "cpuinfo_min_freq",
79 [CPUINFO_MAX_FREQ] = "cpuinfo_max_freq",
80 [CPUINFO_LATENCY] = "cpuinfo_transition_latency",
81 [SCALING_CUR_FREQ] = "scaling_cur_freq",
82 [SCALING_MIN_FREQ] = "scaling_min_freq",
83 [SCALING_MAX_FREQ] = "scaling_max_freq",
84 [STATS_NUM_TRANSITIONS] = "stats/total_trans"
85};
86
87
88static unsigned long sysfs_cpufreq_get_one_value(unsigned int cpu,
89 enum cpufreq_value which)
90{
91 unsigned long value;
92 unsigned int len;
93 char linebuf[MAX_LINE_LEN];
94 char *endp;
95
96 if (which >= MAX_CPUFREQ_VALUE_READ_FILES)
97 return 0;
98
99 len = sysfs_cpufreq_read_file(cpu, cpufreq_value_files[which],
100 linebuf, sizeof(linebuf));
101
102 if (len == 0)
103 return 0;
104
105 value = strtoul(linebuf, &endp, 0);
106
107 if (endp == linebuf || errno == ERANGE)
108 return 0;
109
110 return value;
111}
112
113
114
115enum cpufreq_string {
116 SCALING_DRIVER,
117 SCALING_GOVERNOR,
118 MAX_CPUFREQ_STRING_FILES
119};
120
121static const char *cpufreq_string_files[MAX_CPUFREQ_STRING_FILES] = {
122 [SCALING_DRIVER] = "scaling_driver",
123 [SCALING_GOVERNOR] = "scaling_governor",
124};
125
126
127static char *sysfs_cpufreq_get_one_string(unsigned int cpu,
128 enum cpufreq_string which)
129{
130 char linebuf[MAX_LINE_LEN];
131 char *result;
132 unsigned int len;
133
134 if (which >= MAX_CPUFREQ_STRING_FILES)
135 return NULL;
136
137 len = sysfs_cpufreq_read_file(cpu, cpufreq_string_files[which],
138 linebuf, sizeof(linebuf));
139 if (len == 0)
140 return NULL;
141
142 result = strdup(linebuf);
143 if (result == NULL)
144 return NULL;
145
146 if (result[strlen(result) - 1] == '\n')
147 result[strlen(result) - 1] = '\0';
148
149 return result;
150}
151
152
153
154enum cpufreq_write {
155 WRITE_SCALING_MIN_FREQ,
156 WRITE_SCALING_MAX_FREQ,
157 WRITE_SCALING_GOVERNOR,
158 WRITE_SCALING_SET_SPEED,
159 MAX_CPUFREQ_WRITE_FILES
160};
161
162static const char *cpufreq_write_files[MAX_CPUFREQ_WRITE_FILES] = {
163 [WRITE_SCALING_MIN_FREQ] = "scaling_min_freq",
164 [WRITE_SCALING_MAX_FREQ] = "scaling_max_freq",
165 [WRITE_SCALING_GOVERNOR] = "scaling_governor",
166 [WRITE_SCALING_SET_SPEED] = "scaling_setspeed",
167};
168
169static int sysfs_cpufreq_write_one_value(unsigned int cpu,
170 enum cpufreq_write which,
171 const char *new_value, size_t len)
172{
173 if (which >= MAX_CPUFREQ_WRITE_FILES)
174 return 0;
175
176 if (sysfs_cpufreq_write_file(cpu, cpufreq_write_files[which],
177 new_value, len) != len)
178 return -ENODEV;
179
180 return 0;
181};
182
183unsigned long cpufreq_get_freq_kernel(unsigned int cpu)
184{
185 return sysfs_cpufreq_get_one_value(cpu, SCALING_CUR_FREQ);
186}
187
188unsigned long cpufreq_get_freq_hardware(unsigned int cpu)
189{
190 return sysfs_cpufreq_get_one_value(cpu, CPUINFO_CUR_FREQ);
191}
192
193unsigned long cpufreq_get_transition_latency(unsigned int cpu)
194{
195 return sysfs_cpufreq_get_one_value(cpu, CPUINFO_LATENCY);
196}
197
198int cpufreq_get_hardware_limits(unsigned int cpu,
199 unsigned long *min,
200 unsigned long *max)
201{
202 if ((!min) || (!max))
203 return -EINVAL;
204
205 *min = sysfs_cpufreq_get_one_value(cpu, CPUINFO_MIN_FREQ);
206 if (!*min)
207 return -ENODEV;
208
209 *max = sysfs_cpufreq_get_one_value(cpu, CPUINFO_MAX_FREQ);
210 if (!*max)
211 return -ENODEV;
212
213 return 0;
214}
215
216char *cpufreq_get_driver(unsigned int cpu)
217{
218 return sysfs_cpufreq_get_one_string(cpu, SCALING_DRIVER);
219}
220
221void cpufreq_put_driver(char *ptr)
222{
223 if (!ptr)
224 return;
225 free(ptr);
226}
227
228struct cpufreq_policy *cpufreq_get_policy(unsigned int cpu)
229{
230 struct cpufreq_policy *policy;
231
232 policy = malloc(sizeof(struct cpufreq_policy));
233 if (!policy)
234 return NULL;
235
236 policy->governor = sysfs_cpufreq_get_one_string(cpu, SCALING_GOVERNOR);
237 if (!policy->governor) {
238 free(policy);
239 return NULL;
240 }
241 policy->min = sysfs_cpufreq_get_one_value(cpu, SCALING_MIN_FREQ);
242 policy->max = sysfs_cpufreq_get_one_value(cpu, SCALING_MAX_FREQ);
243 if ((!policy->min) || (!policy->max)) {
244 free(policy->governor);
245 free(policy);
246 return NULL;
247 }
248
249 return policy;
250}
251
252void cpufreq_put_policy(struct cpufreq_policy *policy)
253{
254 if ((!policy) || (!policy->governor))
255 return;
256
257 free(policy->governor);
258 policy->governor = NULL;
259 free(policy);
260}
261
262struct cpufreq_available_governors *cpufreq_get_available_governors(unsigned
263 int cpu)
264{
265 struct cpufreq_available_governors *first = NULL;
266 struct cpufreq_available_governors *current = NULL;
267 char linebuf[MAX_LINE_LEN];
268 unsigned int pos, i;
269 unsigned int len;
270
271 len = sysfs_cpufreq_read_file(cpu, "scaling_available_governors",
272 linebuf, sizeof(linebuf));
273 if (len == 0)
274 return NULL;
275
276 pos = 0;
277 for (i = 0; i < len; i++) {
278 if (linebuf[i] == ' ' || linebuf[i] == '\n') {
279 if (i - pos < 2)
280 continue;
281 if (current) {
282 current->next = malloc(sizeof(*current));
283 if (!current->next)
284 goto error_out;
285 current = current->next;
286 } else {
287 first = malloc(sizeof(*first));
288 if (!first)
289 goto error_out;
290 current = first;
291 }
292 current->first = first;
293 current->next = NULL;
294
295 current->governor = malloc(i - pos + 1);
296 if (!current->governor)
297 goto error_out;
298
299 memcpy(current->governor, linebuf + pos, i - pos);
300 current->governor[i - pos] = '\0';
301 pos = i + 1;
302 }
303 }
304
305 return first;
306
307 error_out:
308 while (first) {
309 current = first->next;
310 if (first->governor)
311 free(first->governor);
312 free(first);
313 first = current;
314 }
315 return NULL;
316}
317
318void cpufreq_put_available_governors(struct cpufreq_available_governors *any)
319{
320 struct cpufreq_available_governors *tmp, *next;
321
322 if (!any)
323 return;
324
325 tmp = any->first;
326 while (tmp) {
327 next = tmp->next;
328 if (tmp->governor)
329 free(tmp->governor);
330 free(tmp);
331 tmp = next;
332 }
333}
334
335
336struct cpufreq_available_frequencies
337*cpufreq_get_available_frequencies(unsigned int cpu)
338{
339 struct cpufreq_available_frequencies *first = NULL;
340 struct cpufreq_available_frequencies *current = NULL;
341 char one_value[SYSFS_PATH_MAX];
342 char linebuf[MAX_LINE_LEN];
343 unsigned int pos, i;
344 unsigned int len;
345
346 len = sysfs_cpufreq_read_file(cpu, "scaling_available_frequencies",
347 linebuf, sizeof(linebuf));
348 if (len == 0)
349 return NULL;
350
351 pos = 0;
352 for (i = 0; i < len; i++) {
353 if (linebuf[i] == ' ' || linebuf[i] == '\n') {
354 if (i - pos < 2)
355 continue;
356 if (i - pos >= SYSFS_PATH_MAX)
357 goto error_out;
358 if (current) {
359 current->next = malloc(sizeof(*current));
360 if (!current->next)
361 goto error_out;
362 current = current->next;
363 } else {
364 first = malloc(sizeof(*first));
365 if (!first)
366 goto error_out;
367 current = first;
368 }
369 current->first = first;
370 current->next = NULL;
371
372 memcpy(one_value, linebuf + pos, i - pos);
373 one_value[i - pos] = '\0';
374 if (sscanf(one_value, "%lu", ¤t->frequency) != 1)
375 goto error_out;
376
377 pos = i + 1;
378 }
379 }
380
381 return first;
382
383 error_out:
384 while (first) {
385 current = first->next;
386 free(first);
387 first = current;
388 }
389 return NULL;
390}
391
392void cpufreq_put_available_frequencies(struct cpufreq_available_frequencies
393 *any) {
394 struct cpufreq_available_frequencies *tmp, *next;
395
396 if (!any)
397 return;
398
399 tmp = any->first;
400 while (tmp) {
401 next = tmp->next;
402 free(tmp);
403 tmp = next;
404 }
405}
406
407static struct cpufreq_affected_cpus *sysfs_get_cpu_list(unsigned int cpu,
408 const char *file)
409{
410 struct cpufreq_affected_cpus *first = NULL;
411 struct cpufreq_affected_cpus *current = NULL;
412 char one_value[SYSFS_PATH_MAX];
413 char linebuf[MAX_LINE_LEN];
414 unsigned int pos, i;
415 unsigned int len;
416
417 len = sysfs_cpufreq_read_file(cpu, file, linebuf, sizeof(linebuf));
418 if (len == 0)
419 return NULL;
420
421 pos = 0;
422 for (i = 0; i < len; i++) {
423 if (i == len || linebuf[i] == ' ' || linebuf[i] == '\n') {
424 if (i - pos < 1)
425 continue;
426 if (i - pos >= SYSFS_PATH_MAX)
427 goto error_out;
428 if (current) {
429 current->next = malloc(sizeof(*current));
430 if (!current->next)
431 goto error_out;
432 current = current->next;
433 } else {
434 first = malloc(sizeof(*first));
435 if (!first)
436 goto error_out;
437 current = first;
438 }
439 current->first = first;
440 current->next = NULL;
441
442 memcpy(one_value, linebuf + pos, i - pos);
443 one_value[i - pos] = '\0';
444
445 if (sscanf(one_value, "%u", ¤t->cpu) != 1)
446 goto error_out;
447
448 pos = i + 1;
449 }
450 }
451
452 return first;
453
454 error_out:
455 while (first) {
456 current = first->next;
457 free(first);
458 first = current;
459 }
460 return NULL;
461}
462
463struct cpufreq_affected_cpus *cpufreq_get_affected_cpus(unsigned int cpu)
464{
465 return sysfs_get_cpu_list(cpu, "affected_cpus");
466}
467
468void cpufreq_put_affected_cpus(struct cpufreq_affected_cpus *any)
469{
470 struct cpufreq_affected_cpus *tmp, *next;
471
472 if (!any)
473 return;
474
475 tmp = any->first;
476 while (tmp) {
477 next = tmp->next;
478 free(tmp);
479 tmp = next;
480 }
481}
482
483
484struct cpufreq_affected_cpus *cpufreq_get_related_cpus(unsigned int cpu)
485{
486 return sysfs_get_cpu_list(cpu, "related_cpus");
487}
488
489void cpufreq_put_related_cpus(struct cpufreq_affected_cpus *any)
490{
491 cpufreq_put_affected_cpus(any);
492}
493
494static int verify_gov(char *new_gov, char *passed_gov)
495{
496 unsigned int i, j = 0;
497
498 if (!passed_gov || (strlen(passed_gov) > 19))
499 return -EINVAL;
500
501 strncpy(new_gov, passed_gov, 20);
502 for (i = 0; i < 20; i++) {
503 if (j) {
504 new_gov[i] = '\0';
505 continue;
506 }
507 if ((new_gov[i] >= 'a') && (new_gov[i] <= 'z'))
508 continue;
509
510 if ((new_gov[i] >= 'A') && (new_gov[i] <= 'Z'))
511 continue;
512
513 if (new_gov[i] == '-')
514 continue;
515
516 if (new_gov[i] == '_')
517 continue;
518
519 if (new_gov[i] == '\0') {
520 j = 1;
521 continue;
522 }
523 return -EINVAL;
524 }
525 new_gov[19] = '\0';
526 return 0;
527}
528
529int cpufreq_set_policy(unsigned int cpu, struct cpufreq_policy *policy)
530{
531 char min[SYSFS_PATH_MAX];
532 char max[SYSFS_PATH_MAX];
533 char gov[SYSFS_PATH_MAX];
534 int ret;
535 unsigned long old_min;
536 int write_max_first;
537
538 if (!policy || !(policy->governor))
539 return -EINVAL;
540
541 if (policy->max < policy->min)
542 return -EINVAL;
543
544 if (verify_gov(gov, policy->governor))
545 return -EINVAL;
546
547 snprintf(min, SYSFS_PATH_MAX, "%lu", policy->min);
548 snprintf(max, SYSFS_PATH_MAX, "%lu", policy->max);
549
550 old_min = sysfs_cpufreq_get_one_value(cpu, SCALING_MIN_FREQ);
551 write_max_first = (old_min && (policy->max < old_min) ? 0 : 1);
552
553 if (write_max_first) {
554 ret = sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MAX_FREQ,
555 max, strlen(max));
556 if (ret)
557 return ret;
558 }
559
560 ret = sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MIN_FREQ, min,
561 strlen(min));
562 if (ret)
563 return ret;
564
565 if (!write_max_first) {
566 ret = sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MAX_FREQ,
567 max, strlen(max));
568 if (ret)
569 return ret;
570 }
571
572 return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_GOVERNOR,
573 gov, strlen(gov));
574}
575
576
577int cpufreq_modify_policy_min(unsigned int cpu, unsigned long min_freq)
578{
579 char value[SYSFS_PATH_MAX];
580
581 snprintf(value, SYSFS_PATH_MAX, "%lu", min_freq);
582
583 return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MIN_FREQ,
584 value, strlen(value));
585}
586
587
588int cpufreq_modify_policy_max(unsigned int cpu, unsigned long max_freq)
589{
590 char value[SYSFS_PATH_MAX];
591
592 snprintf(value, SYSFS_PATH_MAX, "%lu", max_freq);
593
594 return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MAX_FREQ,
595 value, strlen(value));
596}
597
598int cpufreq_modify_policy_governor(unsigned int cpu, char *governor)
599{
600 char new_gov[SYSFS_PATH_MAX];
601
602 if ((!governor) || (strlen(governor) > 19))
603 return -EINVAL;
604
605 if (verify_gov(new_gov, governor))
606 return -EINVAL;
607
608 return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_GOVERNOR,
609 new_gov, strlen(new_gov));
610}
611
612int cpufreq_set_frequency(unsigned int cpu, unsigned long target_frequency)
613{
614 struct cpufreq_policy *pol = cpufreq_get_policy(cpu);
615 char userspace_gov[] = "userspace";
616 char freq[SYSFS_PATH_MAX];
617 int ret;
618
619 if (!pol)
620 return -ENODEV;
621
622 if (strncmp(pol->governor, userspace_gov, 9) != 0) {
623 ret = cpufreq_modify_policy_governor(cpu, userspace_gov);
624 if (ret) {
625 cpufreq_put_policy(pol);
626 return ret;
627 }
628 }
629
630 cpufreq_put_policy(pol);
631
632 snprintf(freq, SYSFS_PATH_MAX, "%lu", target_frequency);
633
634 return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_SET_SPEED,
635 freq, strlen(freq));
636}
637
638struct cpufreq_stats *cpufreq_get_stats(unsigned int cpu,
639 unsigned long long *total_time)
640{
641 struct cpufreq_stats *first = NULL;
642 struct cpufreq_stats *current = NULL;
643 char one_value[SYSFS_PATH_MAX];
644 char linebuf[MAX_LINE_LEN];
645 unsigned int pos, i;
646 unsigned int len;
647
648 len = sysfs_cpufreq_read_file(cpu, "stats/time_in_state",
649 linebuf, sizeof(linebuf));
650 if (len == 0)
651 return NULL;
652
653 *total_time = 0;
654 pos = 0;
655 for (i = 0; i < len; i++) {
656 if (i == strlen(linebuf) || linebuf[i] == '\n') {
657 if (i - pos < 2)
658 continue;
659 if ((i - pos) >= SYSFS_PATH_MAX)
660 goto error_out;
661 if (current) {
662 current->next = malloc(sizeof(*current));
663 if (!current->next)
664 goto error_out;
665 current = current->next;
666 } else {
667 first = malloc(sizeof(*first));
668 if (!first)
669 goto error_out;
670 current = first;
671 }
672 current->first = first;
673 current->next = NULL;
674
675 memcpy(one_value, linebuf + pos, i - pos);
676 one_value[i - pos] = '\0';
677 if (sscanf(one_value, "%lu %llu",
678 ¤t->frequency,
679 ¤t->time_in_state) != 2)
680 goto error_out;
681
682 *total_time = *total_time + current->time_in_state;
683 pos = i + 1;
684 }
685 }
686
687 return first;
688
689 error_out:
690 while (first) {
691 current = first->next;
692 free(first);
693 first = current;
694 }
695 return NULL;
696}
697
698void cpufreq_put_stats(struct cpufreq_stats *any)
699{
700 struct cpufreq_stats *tmp, *next;
701
702 if (!any)
703 return;
704
705 tmp = any->first;
706 while (tmp) {
707 next = tmp->next;
708 free(tmp);
709 tmp = next;
710 }
711}
712
713unsigned long cpufreq_get_transitions(unsigned int cpu)
714{
715 return sysfs_cpufreq_get_one_value(cpu, STATS_NUM_TRANSITIONS);
716}
717
