diff options
Diffstat (limited to 'tools/power/cpupower/lib/cpufreq.c')
| -rw-r--r-- | tools/power/cpupower/lib/cpufreq.c | 550 |
1 files changed, 529 insertions, 21 deletions
diff --git a/tools/power/cpupower/lib/cpufreq.c b/tools/power/cpupower/lib/cpufreq.c index d961101d1..1b993fe1c 100644 --- a/tools/power/cpupower/lib/cpufreq.c +++ b/tools/power/cpupower/lib/cpufreq.c @@ -9,28 +9,190 @@ #include <errno.h> #include <stdlib.h> #include <string.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> #include "cpufreq.h" -#include "sysfs.h" +#include "cpupower_intern.h" -int cpufreq_cpu_exists(unsigned int cpu) +/* CPUFREQ sysfs access **************************************************/ + +/* helper function to read file from /sys into given buffer */ +/* fname is a relative path under "cpuX/cpufreq" dir */ +static unsigned int sysfs_cpufreq_read_file(unsigned int cpu, const char *fname, + char *buf, size_t buflen) { - return sysfs_cpu_exists(cpu); + char path[SYSFS_PATH_MAX]; + + snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/cpufreq/%s", + cpu, fname); + return sysfs_read_file(path, buf, buflen); } +/* helper function to write a new value to a /sys file */ +/* fname is a relative path under "cpuX/cpufreq" dir */ +static unsigned int sysfs_cpufreq_write_file(unsigned int cpu, + const char *fname, + const char *value, size_t len) +{ + char path[SYSFS_PATH_MAX]; + int fd; + ssize_t numwrite; + + snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/cpufreq/%s", + cpu, fname); + + fd = open(path, O_WRONLY); + if (fd == -1) + return 0; + + numwrite = write(fd, value, len); + if (numwrite < 1) { + close(fd); + return 0; + } + + close(fd); + + return (unsigned int) numwrite; +} + +/* read access to files which contain one numeric value */ + +enum cpufreq_value { + CPUINFO_CUR_FREQ, + CPUINFO_MIN_FREQ, + CPUINFO_MAX_FREQ, + CPUINFO_LATENCY, + SCALING_CUR_FREQ, + SCALING_MIN_FREQ, + SCALING_MAX_FREQ, + STATS_NUM_TRANSITIONS, + MAX_CPUFREQ_VALUE_READ_FILES +}; + +static const char *cpufreq_value_files[MAX_CPUFREQ_VALUE_READ_FILES] = { + [CPUINFO_CUR_FREQ] = "cpuinfo_cur_freq", + [CPUINFO_MIN_FREQ] = "cpuinfo_min_freq", + [CPUINFO_MAX_FREQ] = "cpuinfo_max_freq", + [CPUINFO_LATENCY] = "cpuinfo_transition_latency", + [SCALING_CUR_FREQ] = "scaling_cur_freq", + [SCALING_MIN_FREQ] = "scaling_min_freq", + [SCALING_MAX_FREQ] = "scaling_max_freq", + [STATS_NUM_TRANSITIONS] = "stats/total_trans" +}; + + +static unsigned long sysfs_cpufreq_get_one_value(unsigned int cpu, + enum cpufreq_value which) +{ + unsigned long value; + unsigned int len; + char linebuf[MAX_LINE_LEN]; + char *endp; + + if (which >= MAX_CPUFREQ_VALUE_READ_FILES) + return 0; + + len = sysfs_cpufreq_read_file(cpu, cpufreq_value_files[which], + linebuf, sizeof(linebuf)); + + if (len == 0) + return 0; + + value = strtoul(linebuf, &endp, 0); + + if (endp == linebuf || errno == ERANGE) + return 0; + + return value; +} + +/* read access to files which contain one string */ + +enum cpufreq_string { + SCALING_DRIVER, + SCALING_GOVERNOR, + MAX_CPUFREQ_STRING_FILES +}; + +static const char *cpufreq_string_files[MAX_CPUFREQ_STRING_FILES] = { + [SCALING_DRIVER] = "scaling_driver", + [SCALING_GOVERNOR] = "scaling_governor", +}; + + +static char *sysfs_cpufreq_get_one_string(unsigned int cpu, + enum cpufreq_string which) +{ + char linebuf[MAX_LINE_LEN]; + char *result; + unsigned int len; + + if (which >= MAX_CPUFREQ_STRING_FILES) + return NULL; + + len = sysfs_cpufreq_read_file(cpu, cpufreq_string_files[which], + linebuf, sizeof(linebuf)); + if (len == 0) + return NULL; + + result = strdup(linebuf); + if (result == NULL) + return NULL; + + if (result[strlen(result) - 1] == '\n') + result[strlen(result) - 1] = '\0'; + + return result; +} + +/* write access */ + +enum cpufreq_write { + WRITE_SCALING_MIN_FREQ, + WRITE_SCALING_MAX_FREQ, + WRITE_SCALING_GOVERNOR, + WRITE_SCALING_SET_SPEED, + MAX_CPUFREQ_WRITE_FILES +}; + +static const char *cpufreq_write_files[MAX_CPUFREQ_WRITE_FILES] = { + [WRITE_SCALING_MIN_FREQ] = "scaling_min_freq", + [WRITE_SCALING_MAX_FREQ] = "scaling_max_freq", + [WRITE_SCALING_GOVERNOR] = "scaling_governor", + [WRITE_SCALING_SET_SPEED] = "scaling_setspeed", +}; + +static int sysfs_cpufreq_write_one_value(unsigned int cpu, + enum cpufreq_write which, + const char *new_value, size_t len) +{ + if (which >= MAX_CPUFREQ_WRITE_FILES) + return 0; + + if (sysfs_cpufreq_write_file(cpu, cpufreq_write_files[which], + new_value, len) != len) + return -ENODEV; + + return 0; +}; + unsigned long cpufreq_get_freq_kernel(unsigned int cpu) { - return sysfs_get_freq_kernel(cpu); + return sysfs_cpufreq_get_one_value(cpu, SCALING_CUR_FREQ); } unsigned long cpufreq_get_freq_hardware(unsigned int cpu) { - return sysfs_get_freq_hardware(cpu); + return sysfs_cpufreq_get_one_value(cpu, CPUINFO_CUR_FREQ); } unsigned long cpufreq_get_transition_latency(unsigned int cpu) { - return sysfs_get_freq_transition_latency(cpu); + return sysfs_cpufreq_get_one_value(cpu, CPUINFO_LATENCY); } int cpufreq_get_hardware_limits(unsigned int cpu, @@ -39,12 +201,21 @@ int cpufreq_get_hardware_limits(unsigned int cpu, { if ((!min) || (!max)) return -EINVAL; - return sysfs_get_freq_hardware_limits(cpu, min, max); + + *min = sysfs_cpufreq_get_one_value(cpu, CPUINFO_MIN_FREQ); + if (!*min) + return -ENODEV; + + *max = sysfs_cpufreq_get_one_value(cpu, CPUINFO_MAX_FREQ); + if (!*max) + return -ENODEV; + + return 0; } char *cpufreq_get_driver(unsigned int cpu) { - return sysfs_get_freq_driver(cpu); + return sysfs_cpufreq_get_one_string(cpu, SCALING_DRIVER); } void cpufreq_put_driver(char *ptr) @@ -56,7 +227,26 @@ void cpufreq_put_driver(char *ptr) struct cpufreq_policy *cpufreq_get_policy(unsigned int cpu) { - return sysfs_get_freq_policy(cpu); + struct cpufreq_policy *policy; + + policy = malloc(sizeof(struct cpufreq_policy)); + if (!policy) + return NULL; + + policy->governor = sysfs_cpufreq_get_one_string(cpu, SCALING_GOVERNOR); + if (!policy->governor) { + free(policy); + return NULL; + } + policy->min = sysfs_cpufreq_get_one_value(cpu, SCALING_MIN_FREQ); + policy->max = sysfs_cpufreq_get_one_value(cpu, SCALING_MAX_FREQ); + if ((!policy->min) || (!policy->max)) { + free(policy->governor); + free(policy); + return NULL; + } + + return policy; } void cpufreq_put_policy(struct cpufreq_policy *policy) @@ -72,7 +262,57 @@ void cpufreq_put_policy(struct cpufreq_policy *policy) struct cpufreq_available_governors *cpufreq_get_available_governors(unsigned int cpu) { - return sysfs_get_freq_available_governors(cpu); + struct cpufreq_available_governors *first = NULL; + struct cpufreq_available_governors *current = NULL; + char linebuf[MAX_LINE_LEN]; + unsigned int pos, i; + unsigned int len; + + len = sysfs_cpufreq_read_file(cpu, "scaling_available_governors", + linebuf, sizeof(linebuf)); + if (len == 0) + return NULL; + + pos = 0; + for (i = 0; i < len; i++) { + if (linebuf[i] == ' ' || linebuf[i] == '\n') { + if (i - pos < 2) + continue; + if (current) { + current->next = malloc(sizeof(*current)); + if (!current->next) + goto error_out; + current = current->next; + } else { + first = malloc(sizeof(*first)); + if (!first) + goto error_out; + current = first; + } + current->first = first; + current->next = NULL; + + current->governor = malloc(i - pos + 1); + if (!current->governor) + goto error_out; + + memcpy(current->governor, linebuf + pos, i - pos); + current->governor[i - pos] = '\0'; + pos = i + 1; + } + } + + return first; + + error_out: + while (first) { + current = first->next; + if (first->governor) + free(first->governor); + free(first); + first = current; + } + return NULL; } void cpufreq_put_available_governors(struct cpufreq_available_governors *any) @@ -96,7 +336,57 @@ void cpufreq_put_available_governors(struct cpufreq_available_governors *any) struct cpufreq_available_frequencies *cpufreq_get_available_frequencies(unsigned int cpu) { - return sysfs_get_available_frequencies(cpu); + struct cpufreq_available_frequencies *first = NULL; + struct cpufreq_available_frequencies *current = NULL; + char one_value[SYSFS_PATH_MAX]; + char linebuf[MAX_LINE_LEN]; + unsigned int pos, i; + unsigned int len; + + len = sysfs_cpufreq_read_file(cpu, "scaling_available_frequencies", + linebuf, sizeof(linebuf)); + if (len == 0) + return NULL; + + pos = 0; + for (i = 0; i < len; i++) { + if (linebuf[i] == ' ' || linebuf[i] == '\n') { + if (i - pos < 2) + continue; + if (i - pos >= SYSFS_PATH_MAX) + goto error_out; + if (current) { + current->next = malloc(sizeof(*current)); + if (!current->next) + goto error_out; + current = current->next; + } else { + first = malloc(sizeof(*first)); + if (!first) + goto error_out; + current = first; + } + current->first = first; + current->next = NULL; + + memcpy(one_value, linebuf + pos, i - pos); + one_value[i - pos] = '\0'; + if (sscanf(one_value, "%lu", ¤t->frequency) != 1) + goto error_out; + + pos = i + 1; + } + } + + return first; + + error_out: + while (first) { + current = first->next; + free(first); + first = current; + } + return NULL; } void cpufreq_put_available_frequencies(struct cpufreq_available_frequencies @@ -114,10 +404,65 @@ void cpufreq_put_available_frequencies(struct cpufreq_available_frequencies } } +static struct cpufreq_affected_cpus *sysfs_get_cpu_list(unsigned int cpu, + const char *file) +{ + struct cpufreq_affected_cpus *first = NULL; + struct cpufreq_affected_cpus *current = NULL; + char one_value[SYSFS_PATH_MAX]; + char linebuf[MAX_LINE_LEN]; + unsigned int pos, i; + unsigned int len; + + len = sysfs_cpufreq_read_file(cpu, file, linebuf, sizeof(linebuf)); + if (len == 0) + return NULL; + + pos = 0; + for (i = 0; i < len; i++) { + if (i == len || linebuf[i] == ' ' || linebuf[i] == '\n') { + if (i - pos < 1) + continue; + if (i - pos >= SYSFS_PATH_MAX) + goto error_out; + if (current) { + current->next = malloc(sizeof(*current)); + if (!current->next) + goto error_out; + current = current->next; + } else { + first = malloc(sizeof(*first)); + if (!first) + goto error_out; + current = first; + } + current->first = first; + current->next = NULL; + + memcpy(one_value, linebuf + pos, i - pos); + one_value[i - pos] = '\0'; + + if (sscanf(one_value, "%u", ¤t->cpu) != 1) + goto error_out; + + pos = i + 1; + } + } + + return first; + + error_out: + while (first) { + current = first->next; + free(first); + first = current; + } + return NULL; +} struct cpufreq_affected_cpus *cpufreq_get_affected_cpus(unsigned int cpu) { - return sysfs_get_freq_affected_cpus(cpu); + return sysfs_get_cpu_list(cpu, "affected_cpus"); } void cpufreq_put_affected_cpus(struct cpufreq_affected_cpus *any) @@ -138,7 +483,7 @@ void cpufreq_put_affected_cpus(struct cpufreq_affected_cpus *any) struct cpufreq_affected_cpus *cpufreq_get_related_cpus(unsigned int cpu) { - return sysfs_get_freq_related_cpus(cpu); + return sysfs_get_cpu_list(cpu, "related_cpus"); } void cpufreq_put_related_cpus(struct cpufreq_affected_cpus *any) @@ -146,45 +491,208 @@ void cpufreq_put_related_cpus(struct cpufreq_affected_cpus *any) cpufreq_put_affected_cpus(any); } +static int verify_gov(char *new_gov, char *passed_gov) +{ + unsigned int i, j = 0; + + if (!passed_gov || (strlen(passed_gov) > 19)) + return -EINVAL; + + strncpy(new_gov, passed_gov, 20); + for (i = 0; i < 20; i++) { + if (j) { + new_gov[i] = '\0'; + continue; + } + if ((new_gov[i] >= 'a') && (new_gov[i] <= 'z')) + continue; + + if ((new_gov[i] >= 'A') && (new_gov[i] <= 'Z')) + continue; + + if (new_gov[i] == '-') + continue; + + if (new_gov[i] == '_') + continue; + + if (new_gov[i] == '\0') { + j = 1; + continue; + } + return -EINVAL; + } + new_gov[19] = '\0'; + return 0; +} int cpufreq_set_policy(unsigned int cpu, struct cpufreq_policy *policy) { + char min[SYSFS_PATH_MAX]; + char max[SYSFS_PATH_MAX]; + char gov[SYSFS_PATH_MAX]; + int ret; + unsigned long old_min; + int write_max_first; + if (!policy || !(policy->governor)) return -EINVAL; - return sysfs_set_freq_policy(cpu, policy); + if (policy->max < policy->min) + return -EINVAL; + + if (verify_gov(gov, policy->governor)) + return -EINVAL; + + snprintf(min, SYSFS_PATH_MAX, "%lu", policy->min); + snprintf(max, SYSFS_PATH_MAX, "%lu", policy->max); + + old_min = sysfs_cpufreq_get_one_value(cpu, SCALING_MIN_FREQ); + write_max_first = (old_min && (policy->max < old_min) ? 0 : 1); + + if (write_max_first) { + ret = sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MAX_FREQ, + max, strlen(max)); + if (ret) + return ret; + } + + ret = sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MIN_FREQ, min, + strlen(min)); + if (ret) + return ret; + + if (!write_max_first) { + ret = sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MAX_FREQ, + max, strlen(max)); + if (ret) + return ret; + } + + return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_GOVERNOR, + gov, strlen(gov)); } int cpufreq_modify_policy_min(unsigned int cpu, unsigned long min_freq) { - return sysfs_modify_freq_policy_min(cpu, min_freq); + char value[SYSFS_PATH_MAX]; + + snprintf(value, SYSFS_PATH_MAX, "%lu", min_freq); + + return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MIN_FREQ, + value, strlen(value)); } int cpufreq_modify_policy_max(unsigned int cpu, unsigned long max_freq) { - return sysfs_modify_freq_policy_max(cpu, max_freq); -} + char value[SYSFS_PATH_MAX]; + + snprintf(value, SYSFS_PATH_MAX, "%lu", max_freq); + return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MAX_FREQ, + value, strlen(value)); +} int cpufreq_modify_policy_governor(unsigned int cpu, char *governor) { + char new_gov[SYSFS_PATH_MAX]; + if ((!governor) || (strlen(governor) > 19)) return -EINVAL; - return sysfs_modify_freq_policy_governor(cpu, governor); + if (verify_gov(new_gov, governor)) + return -EINVAL; + + return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_GOVERNOR, + new_gov, strlen(new_gov)); } int cpufreq_set_frequency(unsigned int cpu, unsigned long target_frequency) { - return sysfs_set_frequency(cpu, target_frequency); + struct cpufreq_policy *pol = cpufreq_get_policy(cpu); + char userspace_gov[] = "userspace"; + char freq[SYSFS_PATH_MAX]; + int ret; + + if (!pol) + return -ENODEV; + + if (strncmp(pol->governor, userspace_gov, 9) != 0) { + ret = cpufreq_modify_policy_governor(cpu, userspace_gov); + if (ret) { + cpufreq_put_policy(pol); + return ret; + } + } + + cpufreq_put_policy(pol); + + snprintf(freq, SYSFS_PATH_MAX, "%lu", target_frequency); + + return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_SET_SPEED, + freq, strlen(freq)); } struct cpufreq_stats *cpufreq_get_stats(unsigned int cpu, unsigned long long *total_time) { - return sysfs_get_freq_stats(cpu, total_time); + struct cpufreq_stats *first = NULL; + struct cpufreq_stats *current = NULL; + char one_value[SYSFS_PATH_MAX]; + char linebuf[MAX_LINE_LEN]; + unsigned int pos, i; + unsigned int len; + + len = sysfs_cpufreq_read_file(cpu, "stats/time_in_state", + linebuf, sizeof(linebuf)); + if (len == 0) + return NULL; + + *total_time = 0; + pos = 0; + for (i = 0; i < len; i++) { + if (i == strlen(linebuf) || linebuf[i] == '\n') { + if (i - pos < 2) + continue; + if ((i - pos) >= SYSFS_PATH_MAX) + goto error_out; + if (current) { + current->next = malloc(sizeof(*current)); + if (!current->next) + goto error_out; + current = current->next; + } else { + first = malloc(sizeof(*first)); + if (!first) + goto error_out; + current = first; + } + current->first = first; + current->next = NULL; + + memcpy(one_value, linebuf + pos, i - pos); + one_value[i - pos] = '\0'; + if (sscanf(one_value, "%lu %llu", + ¤t->frequency, + ¤t->time_in_state) != 2) + goto error_out; + + *total_time = *total_time + current->time_in_state; + pos = i + 1; + } + } + + return first; + + error_out: + while (first) { + current = first->next; + free(first); + first = current; + } + return NULL; } void cpufreq_put_stats(struct cpufreq_stats *any) @@ -204,5 +712,5 @@ void cpufreq_put_stats(struct cpufreq_stats *any) unsigned long cpufreq_get_transitions(unsigned int cpu) { - return sysfs_get_freq_transitions(cpu); + return sysfs_cpufreq_get_one_value(cpu, STATS_NUM_TRANSITIONS); } |