1 // SPDX-License-Identifier: GPL-2.0-only
3 * (C) 2004-2009 Dominik Brodowski <linux@dominikbrodowski.de>
11 #include <sys/types.h>
17 #include "cpupower_intern.h"
19 /* CPUFREQ sysfs access **************************************************/
21 /* helper function to read file from /sys into given buffer */
22 /* fname is a relative path under "cpuX/cpufreq" dir */
23 static unsigned int sysfs_cpufreq_read_file(unsigned int cpu, const char *fname,
24 char *buf, size_t buflen)
26 char path[SYSFS_PATH_MAX];
28 snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/cpufreq/%s",
30 return cpupower_read_sysfs(path, buf, buflen);
33 /* helper function to write a new value to a /sys file */
34 /* fname is a relative path under "cpuX/cpufreq" dir */
35 static unsigned int sysfs_cpufreq_write_file(unsigned int cpu,
37 const char *value, size_t len)
39 char path[SYSFS_PATH_MAX];
43 snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/cpufreq/%s",
46 fd = open(path, O_WRONLY);
50 numwrite = write(fd, value, len);
58 return (unsigned int) numwrite;
61 /* read access to files which contain one numeric value */
71 STATS_NUM_TRANSITIONS,
72 MAX_CPUFREQ_VALUE_READ_FILES
75 static const char *cpufreq_value_files[MAX_CPUFREQ_VALUE_READ_FILES] = {
76 [CPUINFO_CUR_FREQ] = "cpuinfo_cur_freq",
77 [CPUINFO_MIN_FREQ] = "cpuinfo_min_freq",
78 [CPUINFO_MAX_FREQ] = "cpuinfo_max_freq",
79 [CPUINFO_LATENCY] = "cpuinfo_transition_latency",
80 [SCALING_CUR_FREQ] = "scaling_cur_freq",
81 [SCALING_MIN_FREQ] = "scaling_min_freq",
82 [SCALING_MAX_FREQ] = "scaling_max_freq",
83 [STATS_NUM_TRANSITIONS] = "stats/total_trans"
87 static unsigned long sysfs_cpufreq_get_one_value(unsigned int cpu,
88 enum cpufreq_value which)
92 char linebuf[MAX_LINE_LEN];
95 if (which >= MAX_CPUFREQ_VALUE_READ_FILES)
98 len = sysfs_cpufreq_read_file(cpu, cpufreq_value_files[which],
99 linebuf, sizeof(linebuf));
104 value = strtoul(linebuf, &endp, 0);
106 if (endp == linebuf || errno == ERANGE)
112 /* read access to files which contain one string */
114 enum cpufreq_string {
117 MAX_CPUFREQ_STRING_FILES
120 static const char *cpufreq_string_files[MAX_CPUFREQ_STRING_FILES] = {
121 [SCALING_DRIVER] = "scaling_driver",
122 [SCALING_GOVERNOR] = "scaling_governor",
126 static char *sysfs_cpufreq_get_one_string(unsigned int cpu,
127 enum cpufreq_string which)
129 char linebuf[MAX_LINE_LEN];
133 if (which >= MAX_CPUFREQ_STRING_FILES)
136 len = sysfs_cpufreq_read_file(cpu, cpufreq_string_files[which],
137 linebuf, sizeof(linebuf));
141 result = strdup(linebuf);
145 if (result[strlen(result) - 1] == '\n')
146 result[strlen(result) - 1] = '\0';
154 WRITE_SCALING_MIN_FREQ,
155 WRITE_SCALING_MAX_FREQ,
156 WRITE_SCALING_GOVERNOR,
157 WRITE_SCALING_SET_SPEED,
158 MAX_CPUFREQ_WRITE_FILES
161 static const char *cpufreq_write_files[MAX_CPUFREQ_WRITE_FILES] = {
162 [WRITE_SCALING_MIN_FREQ] = "scaling_min_freq",
163 [WRITE_SCALING_MAX_FREQ] = "scaling_max_freq",
164 [WRITE_SCALING_GOVERNOR] = "scaling_governor",
165 [WRITE_SCALING_SET_SPEED] = "scaling_setspeed",
168 static int sysfs_cpufreq_write_one_value(unsigned int cpu,
169 enum cpufreq_write which,
170 const char *new_value, size_t len)
172 if (which >= MAX_CPUFREQ_WRITE_FILES)
175 if (sysfs_cpufreq_write_file(cpu, cpufreq_write_files[which],
176 new_value, len) != len)
182 unsigned long cpufreq_get_freq_kernel(unsigned int cpu)
184 return sysfs_cpufreq_get_one_value(cpu, SCALING_CUR_FREQ);
187 unsigned long cpufreq_get_freq_hardware(unsigned int cpu)
189 return sysfs_cpufreq_get_one_value(cpu, CPUINFO_CUR_FREQ);
192 unsigned long cpufreq_get_transition_latency(unsigned int cpu)
194 return sysfs_cpufreq_get_one_value(cpu, CPUINFO_LATENCY);
197 int cpufreq_get_hardware_limits(unsigned int cpu,
201 if ((!min) || (!max))
204 *min = sysfs_cpufreq_get_one_value(cpu, CPUINFO_MIN_FREQ);
208 *max = sysfs_cpufreq_get_one_value(cpu, CPUINFO_MAX_FREQ);
215 char *cpufreq_get_driver(unsigned int cpu)
217 return sysfs_cpufreq_get_one_string(cpu, SCALING_DRIVER);
220 void cpufreq_put_driver(char *ptr)
227 struct cpufreq_policy *cpufreq_get_policy(unsigned int cpu)
229 struct cpufreq_policy *policy;
231 policy = malloc(sizeof(struct cpufreq_policy));
235 policy->governor = sysfs_cpufreq_get_one_string(cpu, SCALING_GOVERNOR);
236 if (!policy->governor) {
240 policy->min = sysfs_cpufreq_get_one_value(cpu, SCALING_MIN_FREQ);
241 policy->max = sysfs_cpufreq_get_one_value(cpu, SCALING_MAX_FREQ);
242 if ((!policy->min) || (!policy->max)) {
243 free(policy->governor);
251 void cpufreq_put_policy(struct cpufreq_policy *policy)
253 if ((!policy) || (!policy->governor))
256 free(policy->governor);
257 policy->governor = NULL;
261 struct cpufreq_available_governors *cpufreq_get_available_governors(unsigned
264 struct cpufreq_available_governors *first = NULL;
265 struct cpufreq_available_governors *current = NULL;
266 char linebuf[MAX_LINE_LEN];
270 len = sysfs_cpufreq_read_file(cpu, "scaling_available_governors",
271 linebuf, sizeof(linebuf));
276 for (i = 0; i < len; i++) {
277 if (linebuf[i] == ' ' || linebuf[i] == '\n') {
281 current->next = malloc(sizeof(*current));
284 current = current->next;
286 first = malloc(sizeof(*first));
291 current->first = first;
292 current->next = NULL;
294 current->governor = malloc(i - pos + 1);
295 if (!current->governor)
298 memcpy(current->governor, linebuf + pos, i - pos);
299 current->governor[i - pos] = '\0';
308 current = first->next;
310 free(first->governor);
317 void cpufreq_put_available_governors(struct cpufreq_available_governors *any)
319 struct cpufreq_available_governors *tmp, *next;
335 struct cpufreq_available_frequencies
336 *cpufreq_get_available_frequencies(unsigned int cpu)
338 struct cpufreq_available_frequencies *first = NULL;
339 struct cpufreq_available_frequencies *current = NULL;
340 char one_value[SYSFS_PATH_MAX];
341 char linebuf[MAX_LINE_LEN];
345 len = sysfs_cpufreq_read_file(cpu, "scaling_available_frequencies",
346 linebuf, sizeof(linebuf));
351 for (i = 0; i < len; i++) {
352 if (linebuf[i] == ' ' || linebuf[i] == '\n') {
355 if (i - pos >= SYSFS_PATH_MAX)
358 current->next = malloc(sizeof(*current));
361 current = current->next;
363 first = malloc(sizeof(*first));
368 current->first = first;
369 current->next = NULL;
371 memcpy(one_value, linebuf + pos, i - pos);
372 one_value[i - pos] = '\0';
373 if (sscanf(one_value, "%lu", ¤t->frequency) != 1)
384 current = first->next;
391 struct cpufreq_available_frequencies
392 *cpufreq_get_boost_frequencies(unsigned int cpu)
394 struct cpufreq_available_frequencies *first = NULL;
395 struct cpufreq_available_frequencies *current = NULL;
396 char one_value[SYSFS_PATH_MAX];
397 char linebuf[MAX_LINE_LEN];
401 len = sysfs_cpufreq_read_file(cpu, "scaling_boost_frequencies",
402 linebuf, sizeof(linebuf));
407 for (i = 0; i < len; i++) {
408 if (linebuf[i] == ' ' || linebuf[i] == '\n') {
411 if (i - pos >= SYSFS_PATH_MAX)
414 current->next = malloc(sizeof(*current));
417 current = current->next;
419 first = malloc(sizeof(*first));
424 current->first = first;
425 current->next = NULL;
427 memcpy(one_value, linebuf + pos, i - pos);
428 one_value[i - pos] = '\0';
429 if (sscanf(one_value, "%lu", ¤t->frequency) != 1)
440 current = first->next;
447 void cpufreq_put_available_frequencies(struct cpufreq_available_frequencies *any)
449 struct cpufreq_available_frequencies *tmp, *next;
462 void cpufreq_put_boost_frequencies(struct cpufreq_available_frequencies *any)
464 cpufreq_put_available_frequencies(any);
467 static struct cpufreq_affected_cpus *sysfs_get_cpu_list(unsigned int cpu,
470 struct cpufreq_affected_cpus *first = NULL;
471 struct cpufreq_affected_cpus *current = NULL;
472 char one_value[SYSFS_PATH_MAX];
473 char linebuf[MAX_LINE_LEN];
477 len = sysfs_cpufreq_read_file(cpu, file, linebuf, sizeof(linebuf));
482 for (i = 0; i < len; i++) {
483 if (i == len || linebuf[i] == ' ' || linebuf[i] == '\n') {
486 if (i - pos >= SYSFS_PATH_MAX)
489 current->next = malloc(sizeof(*current));
492 current = current->next;
494 first = malloc(sizeof(*first));
499 current->first = first;
500 current->next = NULL;
502 memcpy(one_value, linebuf + pos, i - pos);
503 one_value[i - pos] = '\0';
505 if (sscanf(one_value, "%u", ¤t->cpu) != 1)
516 current = first->next;
523 struct cpufreq_affected_cpus *cpufreq_get_affected_cpus(unsigned int cpu)
525 return sysfs_get_cpu_list(cpu, "affected_cpus");
528 void cpufreq_put_affected_cpus(struct cpufreq_affected_cpus *any)
530 struct cpufreq_affected_cpus *tmp, *next;
544 struct cpufreq_affected_cpus *cpufreq_get_related_cpus(unsigned int cpu)
546 return sysfs_get_cpu_list(cpu, "related_cpus");
549 void cpufreq_put_related_cpus(struct cpufreq_affected_cpus *any)
551 cpufreq_put_affected_cpus(any);
554 static int verify_gov(char *new_gov, char *passed_gov)
556 unsigned int i, j = 0;
558 if (!passed_gov || (strlen(passed_gov) > 19))
561 strncpy(new_gov, passed_gov, 20);
562 for (i = 0; i < 20; i++) {
567 if ((new_gov[i] >= 'a') && (new_gov[i] <= 'z'))
570 if ((new_gov[i] >= 'A') && (new_gov[i] <= 'Z'))
573 if (new_gov[i] == '-')
576 if (new_gov[i] == '_')
579 if (new_gov[i] == '\0') {
589 int cpufreq_set_policy(unsigned int cpu, struct cpufreq_policy *policy)
591 char min[SYSFS_PATH_MAX];
592 char max[SYSFS_PATH_MAX];
593 char gov[SYSFS_PATH_MAX];
595 unsigned long old_min;
598 if (!policy || !(policy->governor))
601 if (policy->max < policy->min)
604 if (verify_gov(gov, policy->governor))
607 snprintf(min, SYSFS_PATH_MAX, "%lu", policy->min);
608 snprintf(max, SYSFS_PATH_MAX, "%lu", policy->max);
610 old_min = sysfs_cpufreq_get_one_value(cpu, SCALING_MIN_FREQ);
611 write_max_first = (old_min && (policy->max < old_min) ? 0 : 1);
613 if (write_max_first) {
614 ret = sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MAX_FREQ,
620 ret = sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MIN_FREQ, min,
625 if (!write_max_first) {
626 ret = sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MAX_FREQ,
632 return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_GOVERNOR,
637 int cpufreq_modify_policy_min(unsigned int cpu, unsigned long min_freq)
639 char value[SYSFS_PATH_MAX];
641 snprintf(value, SYSFS_PATH_MAX, "%lu", min_freq);
643 return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MIN_FREQ,
644 value, strlen(value));
648 int cpufreq_modify_policy_max(unsigned int cpu, unsigned long max_freq)
650 char value[SYSFS_PATH_MAX];
652 snprintf(value, SYSFS_PATH_MAX, "%lu", max_freq);
654 return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MAX_FREQ,
655 value, strlen(value));
658 int cpufreq_modify_policy_governor(unsigned int cpu, char *governor)
660 char new_gov[SYSFS_PATH_MAX];
662 if ((!governor) || (strlen(governor) > 19))
665 if (verify_gov(new_gov, governor))
668 return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_GOVERNOR,
669 new_gov, strlen(new_gov));
672 int cpufreq_set_frequency(unsigned int cpu, unsigned long target_frequency)
674 struct cpufreq_policy *pol = cpufreq_get_policy(cpu);
675 char userspace_gov[] = "userspace";
676 char freq[SYSFS_PATH_MAX];
682 if (strncmp(pol->governor, userspace_gov, 9) != 0) {
683 ret = cpufreq_modify_policy_governor(cpu, userspace_gov);
685 cpufreq_put_policy(pol);
690 cpufreq_put_policy(pol);
692 snprintf(freq, SYSFS_PATH_MAX, "%lu", target_frequency);
694 return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_SET_SPEED,
698 struct cpufreq_stats *cpufreq_get_stats(unsigned int cpu,
699 unsigned long long *total_time)
701 struct cpufreq_stats *first = NULL;
702 struct cpufreq_stats *current = NULL;
703 char one_value[SYSFS_PATH_MAX];
704 char linebuf[MAX_LINE_LEN];
708 len = sysfs_cpufreq_read_file(cpu, "stats/time_in_state",
709 linebuf, sizeof(linebuf));
715 for (i = 0; i < len; i++) {
716 if (i == strlen(linebuf) || linebuf[i] == '\n') {
719 if ((i - pos) >= SYSFS_PATH_MAX)
722 current->next = malloc(sizeof(*current));
725 current = current->next;
727 first = malloc(sizeof(*first));
732 current->first = first;
733 current->next = NULL;
735 memcpy(one_value, linebuf + pos, i - pos);
736 one_value[i - pos] = '\0';
737 if (sscanf(one_value, "%lu %llu",
739 ¤t->time_in_state) != 2)
742 *total_time = *total_time + current->time_in_state;
751 current = first->next;
758 void cpufreq_put_stats(struct cpufreq_stats *any)
760 struct cpufreq_stats *tmp, *next;
773 unsigned long cpufreq_get_transitions(unsigned int cpu)
775 return sysfs_cpufreq_get_one_value(cpu, STATS_NUM_TRANSITIONS);