power: refactor ACPI and intel_pstate support
authorAnatoly Burakov <anatoly.burakov@intel.com>
Thu, 8 Jul 2021 15:38:23 +0000 (16:38 +0100)
committerDavid Marchand <david.marchand@redhat.com>
Thu, 8 Jul 2021 20:32:13 +0000 (22:32 +0200)
Currently, ACPI and PSTATE modes have lots of code duplication,
confusing logic, and a bunch of other issues that can, and have, led to
various bugs and resource leaks.

This commit factors out the common parts of sysfs reading/writing for
ACPI and PSTATE drivers.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Signed-off-by: David Hunt <david.hunt@intel.com>
lib/power/power_acpi_cpufreq.c
lib/power/power_common.c
lib/power/power_common.h
lib/power/power_pstate_cpufreq.c

index 1b8c69c..1e8aeb8 100644 (file)
 #include "power_acpi_cpufreq.h"
 #include "power_common.h"
 
-#ifdef RTE_LIBRTE_POWER_DEBUG
-#define POWER_DEBUG_TRACE(fmt, args...) do { \
-               RTE_LOG(ERR, POWER, "%s: " fmt, __func__, ## args); \
-} while (0)
-#else
-#define POWER_DEBUG_TRACE(fmt, args...)
-#endif
-
-#define FOPEN_OR_ERR_RET(f, retval) do { \
-               if ((f) == NULL) { \
-                       RTE_LOG(ERR, POWER, "File not opened\n"); \
-                       return retval; \
-               } \
-} while (0)
-
-#define FOPS_OR_NULL_GOTO(ret, label) do { \
-               if ((ret) == NULL) { \
-                       RTE_LOG(ERR, POWER, "fgets returns nothing\n"); \
-                       goto label; \
-               } \
-} while (0)
-
-#define FOPS_OR_ERR_GOTO(ret, label) do { \
-               if ((ret) < 0) { \
-                       RTE_LOG(ERR, POWER, "File operations failed\n"); \
-                       goto label; \
-               } \
-} while (0)
-
 #define STR_SIZE     1024
 #define POWER_CONVERT_TO_DECIMAL 10
 
 #define POWER_GOVERNOR_USERSPACE "userspace"
-#define POWER_SYSFILE_GOVERNOR   \
-               "/sys/devices/system/cpu/cpu%u/cpufreq/scaling_governor"
 #define POWER_SYSFILE_AVAIL_FREQ \
                "/sys/devices/system/cpu/cpu%u/cpufreq/scaling_available_frequencies"
 #define POWER_SYSFILE_SETSPEED   \
@@ -135,53 +104,18 @@ set_freq_internal(struct acpi_power_info *pi, uint32_t idx)
 static int
 power_set_governor_userspace(struct acpi_power_info *pi)
 {
-       FILE *f;
-       int ret = -1;
-       char buf[BUFSIZ];
-       char fullpath[PATH_MAX];
-       char *s;
-       int val;
-
-       snprintf(fullpath, sizeof(fullpath), POWER_SYSFILE_GOVERNOR,
-                       pi->lcore_id);
-       f = fopen(fullpath, "rw+");
-       FOPEN_OR_ERR_RET(f, ret);
-
-       s = fgets(buf, sizeof(buf), f);
-       FOPS_OR_NULL_GOTO(s, out);
-       /* Strip off terminating '\n' */
-       strtok(buf, "\n");
-
-       /* Save the original governor */
-       rte_strscpy(pi->governor_ori, buf, sizeof(pi->governor_ori));
-
-       /* Check if current governor is userspace */
-       if (strncmp(buf, POWER_GOVERNOR_USERSPACE,
-                       sizeof(POWER_GOVERNOR_USERSPACE)) == 0) {
-               ret = 0;
-               POWER_DEBUG_TRACE("Power management governor of lcore %u is "
-                               "already userspace\n", pi->lcore_id);
-               goto out;
-       }
-
-       /* Write 'userspace' to the governor */
-       val = fseek(f, 0, SEEK_SET);
-       FOPS_OR_ERR_GOTO(val, out);
-
-       val = fputs(POWER_GOVERNOR_USERSPACE, f);
-       FOPS_OR_ERR_GOTO(val, out);
-
-       /* We need to flush to see if the fputs succeeds */
-       val = fflush(f);
-       FOPS_OR_ERR_GOTO(val, out);
-
-       ret = 0;
-       RTE_LOG(INFO, POWER, "Power management governor of lcore %u has been "
-                       "set to user space successfully\n", pi->lcore_id);
-out:
-       fclose(f);
+       return power_set_governor(pi->lcore_id, POWER_GOVERNOR_USERSPACE,
+                       pi->governor_ori, sizeof(pi->governor_ori));
+}
 
-       return ret;
+/**
+ * It is to check the governor and then set the original governor back if
+ * needed by writing the sys file.
+ */
+static int
+power_set_governor_original(struct acpi_power_info *pi)
+{
+       return power_set_governor(pi->lcore_id, pi->governor_ori, NULL, 0);
 }
 
 /**
@@ -195,22 +129,21 @@ power_get_available_freqs(struct acpi_power_info *pi)
        int ret = -1, i, count;
        char *p;
        char buf[BUFSIZ];
-       char fullpath[PATH_MAX];
        char *freqs[RTE_MAX_LCORE_FREQS];
-       char *s;
-
-       snprintf(fullpath, sizeof(fullpath), POWER_SYSFILE_AVAIL_FREQ,
-                       pi->lcore_id);
-       f = fopen(fullpath, "r");
-       FOPEN_OR_ERR_RET(f, ret);
 
-       s = fgets(buf, sizeof(buf), f);
-       FOPS_OR_NULL_GOTO(s, out);
+       open_core_sysfs_file(&f, "r", POWER_SYSFILE_AVAIL_FREQ, pi->lcore_id);
+       if (f == NULL) {
+               RTE_LOG(ERR, POWER, "failed to open %s\n",
+                               POWER_SYSFILE_AVAIL_FREQ);
+               goto out;
+       }
 
-       /* Strip the line break if there is */
-       p = strchr(buf, '\n');
-       if (p != NULL)
-               *p = 0;
+       ret = read_core_sysfs_s(f, buf, sizeof(buf));
+       if ((ret) < 0) {
+               RTE_LOG(ERR, POWER, "Failed to read %s\n",
+                               POWER_SYSFILE_AVAIL_FREQ);
+               goto out;
+       }
 
        /* Split string into at most RTE_MAX_LCORE_FREQS frequencies */
        count = rte_strsplit(buf, sizeof(buf), freqs,
@@ -250,7 +183,8 @@ power_get_available_freqs(struct acpi_power_info *pi)
        POWER_DEBUG_TRACE("%d frequency(s) of lcore %u are available\n",
                        count, pi->lcore_id);
 out:
-       fclose(f);
+       if (f != NULL)
+               fclose(f);
 
        return ret;
 }
@@ -262,18 +196,23 @@ static int
 power_init_for_setting_freq(struct acpi_power_info *pi)
 {
        FILE *f;
-       char fullpath[PATH_MAX];
        char buf[BUFSIZ];
        uint32_t i, freq;
-       char *s;
+       int ret;
 
-       snprintf(fullpath, sizeof(fullpath), POWER_SYSFILE_SETSPEED,
-                       pi->lcore_id);
-       f = fopen(fullpath, "rw+");
-       FOPEN_OR_ERR_RET(f, -1);
+       open_core_sysfs_file(&f, "rw+", POWER_SYSFILE_SETSPEED, pi->lcore_id);
+       if (f == NULL) {
+               RTE_LOG(ERR, POWER, "Failed to open %s\n",
+                               POWER_SYSFILE_SETSPEED);
+               goto err;
+       }
 
-       s = fgets(buf, sizeof(buf), f);
-       FOPS_OR_NULL_GOTO(s, out);
+       ret = read_core_sysfs_s(f, buf, sizeof(buf));
+       if ((ret) < 0) {
+               RTE_LOG(ERR, POWER, "Failed to read %s\n",
+                               POWER_SYSFILE_SETSPEED);
+               goto err;
+       }
 
        freq = strtoul(buf, NULL, POWER_CONVERT_TO_DECIMAL);
        for (i = 0; i < pi->nb_freqs; i++) {
@@ -284,8 +223,9 @@ power_init_for_setting_freq(struct acpi_power_info *pi)
                }
        }
 
-out:
-       fclose(f);
+err:
+       if (f != NULL)
+               fclose(f);
 
        return -1;
 }
@@ -369,54 +309,6 @@ fail:
        return -1;
 }
 
-/**
- * It is to check the governor and then set the original governor back if
- * needed by writing the sys file.
- */
-static int
-power_set_governor_original(struct acpi_power_info *pi)
-{
-       FILE *f;
-       int ret = -1;
-       char buf[BUFSIZ];
-       char fullpath[PATH_MAX];
-       char *s;
-       int val;
-
-       snprintf(fullpath, sizeof(fullpath), POWER_SYSFILE_GOVERNOR,
-                       pi->lcore_id);
-       f = fopen(fullpath, "rw+");
-       FOPEN_OR_ERR_RET(f, ret);
-
-       s = fgets(buf, sizeof(buf), f);
-       FOPS_OR_NULL_GOTO(s, out);
-
-       /* Check if the governor to be set is the same as current */
-       if (strncmp(buf, pi->governor_ori, sizeof(pi->governor_ori)) == 0) {
-               ret = 0;
-               POWER_DEBUG_TRACE("Power management governor of lcore %u "
-                               "has already been set to %s\n",
-                               pi->lcore_id, pi->governor_ori);
-               goto out;
-       }
-
-       /* Write back the original governor */
-       val = fseek(f, 0, SEEK_SET);
-       FOPS_OR_ERR_GOTO(val, out);
-
-       val = fputs(pi->governor_ori, f);
-       FOPS_OR_ERR_GOTO(val, out);
-
-       ret = 0;
-       RTE_LOG(INFO, POWER, "Power management governor of lcore %u "
-                       "has been set back to %s successfully\n",
-                       pi->lcore_id, pi->governor_ori);
-out:
-       fclose(f);
-
-       return ret;
-}
-
 int
 power_acpi_cpufreq_exit(unsigned int lcore_id)
 {
index 67e3318..1e09fac 100644 (file)
@@ -3,19 +3,25 @@
  */
 
 #include <limits.h>
+#include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 
+#include <rte_log.h>
+#include <rte_string_fns.h>
+
 #include "power_common.h"
 
 #define POWER_SYSFILE_SCALING_DRIVER   \
                "/sys/devices/system/cpu/cpu%u/cpufreq/scaling_driver"
+#define POWER_SYSFILE_GOVERNOR  \
+               "/sys/devices/system/cpu/cpu%u/cpufreq/scaling_governor"
+#define POWER_CONVERT_TO_DECIMAL 10
 
 int
 cpufreq_check_scaling_driver(const char *driver_name)
 {
        unsigned int lcore_id = 0; /* always check core 0 */
-       char fullpath[PATH_MAX];
        char readbuf[PATH_MAX];
        size_t end_idx;
        char *s;
@@ -24,10 +30,8 @@ cpufreq_check_scaling_driver(const char *driver_name)
        /*
         * Check if scaling driver matches what we expect.
         */
-       snprintf(fullpath, sizeof(fullpath), POWER_SYSFILE_SCALING_DRIVER,
+       open_core_sysfs_file(&f, "r", POWER_SYSFILE_SCALING_DRIVER,
                        lcore_id);
-       f = fopen(fullpath, "r");
-
        /* if there's no driver at all, bail out */
        if (f == NULL)
                return 0;
@@ -58,3 +62,143 @@ cpufreq_check_scaling_driver(const char *driver_name)
         */
        return 1;
 }
+
+int
+open_core_sysfs_file(FILE **f, const char *mode, const char *format, ...)
+{
+       char fullpath[PATH_MAX];
+       va_list ap;
+       FILE *tmpf;
+
+       va_start(ap, format);
+       vsnprintf(fullpath, sizeof(fullpath), format, ap);
+       va_end(ap);
+       tmpf = fopen(fullpath, mode);
+       *f = tmpf;
+       if (tmpf == NULL)
+               return -1;
+
+       return 0;
+}
+
+int
+read_core_sysfs_u32(FILE *f, uint32_t *val)
+{
+       char buf[BUFSIZ];
+       uint32_t fval;
+       char *s;
+
+       s = fgets(buf, sizeof(buf), f);
+       if (s == NULL)
+               return -1;
+
+       /* fgets puts null terminator in, but do this just in case */
+       buf[BUFSIZ - 1] = '\0';
+
+       /* strip off any terminating newlines */
+       *strchrnul(buf, '\n') = '\0';
+
+       fval = strtoul(buf, NULL, POWER_CONVERT_TO_DECIMAL);
+
+       /* write the value */
+       *val = fval;
+
+       return 0;
+}
+
+int
+read_core_sysfs_s(FILE *f, char *buf, unsigned int len)
+{
+       char *s;
+
+       s = fgets(buf, len, f);
+       if (s == NULL)
+               return -1;
+
+       /* fgets puts null terminator in, but do this just in case */
+       buf[len - 1] = '\0';
+
+       /* strip off any terminating newlines */
+       *strchrnul(buf, '\n') = '\0';
+
+       return 0;
+}
+
+int
+write_core_sysfs_s(FILE *f, const char *str)
+{
+       int ret;
+
+       ret = fseek(f, 0, SEEK_SET);
+       if (ret != 0)
+               return -1;
+
+       ret = fputs(str, f);
+       if (ret < 0)
+               return -1;
+
+       /* flush the output */
+       ret = fflush(f);
+       if (ret != 0)
+               return -1;
+
+       return 0;
+}
+
+/**
+ * It is to check the current scaling governor by reading sys file, and then
+ * set it into 'performance' if it is not by writing the sys file. The original
+ * governor will be saved for rolling back.
+ */
+int
+power_set_governor(unsigned int lcore_id, const char *new_governor,
+               char *orig_governor, size_t orig_governor_len)
+{
+       FILE *f_governor = NULL;
+       int ret = -1;
+       char buf[BUFSIZ];
+
+       open_core_sysfs_file(&f_governor, "rw+", POWER_SYSFILE_GOVERNOR,
+                       lcore_id);
+       if (f_governor == NULL) {
+               RTE_LOG(ERR, POWER, "failed to open %s\n",
+                               POWER_SYSFILE_GOVERNOR);
+               goto out;
+       }
+
+       ret = read_core_sysfs_s(f_governor, buf, sizeof(buf));
+       if (ret < 0) {
+               RTE_LOG(ERR, POWER, "Failed to read %s\n",
+                               POWER_SYSFILE_GOVERNOR);
+               goto out;
+       }
+
+       /* Save the original governor, if it was provided */
+       if (orig_governor)
+               rte_strscpy(orig_governor, buf, orig_governor_len);
+
+       /* Check if current governor is already what we want */
+       if (strcmp(buf, new_governor) == 0) {
+               ret = 0;
+               POWER_DEBUG_TRACE("Power management governor of lcore %u is "
+                               "already %s\n", lcore_id, new_governor);
+               goto out;
+       }
+
+       /* Write the new governor */
+       ret = write_core_sysfs_s(f_governor, new_governor);
+       if (ret < 0) {
+               RTE_LOG(ERR, POWER, "Failed to write %s\n",
+                               POWER_SYSFILE_GOVERNOR);
+               goto out;
+       }
+
+       ret = 0;
+       RTE_LOG(INFO, POWER, "Power management governor of lcore %u has been "
+                       "set to '%s' successfully\n", lcore_id, new_governor);
+out:
+       if (f_governor != NULL)
+               fclose(f_governor);
+
+       return ret;
+}
index fab3ca9..0b264ed 100644 (file)
@@ -5,9 +5,28 @@
 #ifndef _POWER_COMMON_H_
 #define _POWER_COMMON_H_
 
+#include <inttypes.h>
+
+#include <rte_common.h>
+
 #define RTE_POWER_INVALID_FREQ_INDEX (~0)
 
+
+#ifdef RTE_LIBRTE_POWER_DEBUG
+#define POWER_DEBUG_TRACE(fmt, args...) \
+               RTE_LOG(ERR, POWER, "%s: " fmt, __func__, ## args)
+#else
+#define POWER_DEBUG_TRACE(fmt, args...)
+#endif
+
 /* check if scaling driver matches one we want */
 int cpufreq_check_scaling_driver(const char *driver);
+int power_set_governor(unsigned int lcore_id, const char *new_governor,
+               char *orig_governor, size_t orig_governor_len);
+int open_core_sysfs_file(FILE **f, const char *mode, const char *format, ...)
+               __rte_format_printf(3, 4);
+int read_core_sysfs_u32(FILE *f, uint32_t *val);
+int read_core_sysfs_s(FILE *f, char *buf, unsigned int len);
+int write_core_sysfs_s(FILE *f, const char *str);
 
 #endif /* _POWER_COMMON_H_ */
index 2cfc54a..ba28ddc 100644 (file)
 #include "power_pstate_cpufreq.h"
 #include "power_common.h"
 
-
-#ifdef RTE_LIBRTE_POWER_DEBUG
-#define POWER_DEBUG_TRACE(fmt, args...) do { \
-               RTE_LOG(ERR, POWER, "%s: " fmt, __func__, ## args); \
-} while (0)
-#else
-#define POWER_DEBUG_TRACE(fmt, args...)
-#endif
-
-#define FOPEN_OR_ERR_RET(f, retval) do { \
-               if ((f) == NULL) { \
-                       RTE_LOG(ERR, POWER, "File not opened\n"); \
-                       return retval; \
-               } \
-} while (0)
-
-#define FOPS_OR_NULL_GOTO(ret, label) do { \
-               if ((ret) == NULL) { \
-                       RTE_LOG(ERR, POWER, "fgets returns nothing\n"); \
-                       goto label; \
-               } \
-} while (0)
-
-#define FOPS_OR_ERR_GOTO(ret, label) do { \
-               if ((ret) < 0) { \
-                       RTE_LOG(ERR, POWER, "File operations failed\n"); \
-                       goto label; \
-               } \
-} while (0)
-
 /* macros used for rounding frequency to nearest 100000 */
 #define FREQ_ROUNDING_DELTA 50000
 #define ROUND_FREQ_TO_N_100000 100000
 
-#define POWER_CONVERT_TO_DECIMAL 10
 #define BUS_FREQ     100000
 
 #define POWER_GOVERNOR_PERF "performance"
-#define POWER_SYSFILE_GOVERNOR  \
-               "/sys/devices/system/cpu/cpu%u/cpufreq/scaling_governor"
 #define POWER_SYSFILE_MAX_FREQ \
                "/sys/devices/system/cpu/cpu%u/cpufreq/scaling_max_freq"
 #define POWER_SYSFILE_MIN_FREQ  \
@@ -154,91 +121,78 @@ out:      close(fd);
 static int
 power_init_for_setting_freq(struct pstate_power_info *pi)
 {
-       FILE *f_min, *f_max, *f_base = NULL, *f_base_max;
-       char fullpath_min[PATH_MAX];
-       char fullpath_max[PATH_MAX];
-       char fullpath_base[PATH_MAX];
-       char fullpath_base_max[PATH_MAX];
-       char buf_base[BUFSIZ];
-       char *s_base;
-       char *s_base_max;
-       uint32_t base_ratio = 0;
-       uint32_t base_max_ratio = 0;
-       uint64_t max_non_turbo = 0;
-       int  ret_val = 0;
-
-       snprintf(fullpath_base_max,
-                       sizeof(fullpath_base_max),
-                       POWER_SYSFILE_BASE_MAX_FREQ,
-                       pi->lcore_id);
-       f_base_max = fopen(fullpath_base_max, "r");
-       FOPEN_OR_ERR_RET(f_base_max, -1);
-       if (f_base_max != NULL) {
-               s_base_max = fgets(buf_base, sizeof(buf_base), f_base_max);
-
-               /* close the file unconditionally */
-               fclose(f_base_max);
-               f_base_max = NULL;
-
-               FOPS_OR_NULL_GOTO(s_base_max, out);
+       FILE *f_base = NULL, *f_base_max = NULL, *f_min = NULL, *f_max = NULL;
+       uint32_t base_ratio, base_max_ratio;
+       uint64_t max_non_turbo;
+       int ret;
 
-               buf_base[BUFSIZ-1] = '\0';
-               if (strlen(buf_base))
-                       /* Strip off terminating '\n' */
-                       strtok(buf_base, "\n");
-
-               base_max_ratio =
-                       strtoul(buf_base, NULL, POWER_CONVERT_TO_DECIMAL)
-                               / BUS_FREQ;
+       /* open all files we expect to have open */
+       open_core_sysfs_file(&f_base_max, "r", POWER_SYSFILE_BASE_MAX_FREQ,
+                       pi->lcore_id);
+       if (f_base_max == NULL) {
+               RTE_LOG(ERR, POWER, "failed to open %s\n",
+                               POWER_SYSFILE_BASE_MAX_FREQ);
+               goto err;
        }
 
-       snprintf(fullpath_min, sizeof(fullpath_min), POWER_SYSFILE_MIN_FREQ,
+       open_core_sysfs_file(&f_min, "rw+", POWER_SYSFILE_MIN_FREQ,
                        pi->lcore_id);
-       f_min = fopen(fullpath_min, "rw+");
-       FOPEN_OR_ERR_RET(f_min, -1);
+       if (f_min == NULL) {
+               RTE_LOG(ERR, POWER, "failed to open %s\n",
+                               POWER_SYSFILE_MIN_FREQ);
+               goto err;
+       }
 
-       snprintf(fullpath_max, sizeof(fullpath_max), POWER_SYSFILE_MAX_FREQ,
+       open_core_sysfs_file(&f_max, "rw+", POWER_SYSFILE_MAX_FREQ,
                        pi->lcore_id);
-       f_max = fopen(fullpath_max, "rw+");
-       if (f_max == NULL)
-               fclose(f_min);
-       FOPEN_OR_ERR_RET(f_max, -1);
-
-       pi->f_cur_min = f_min;
-       pi->f_cur_max = f_max;
+       if (f_max == NULL) {
+               RTE_LOG(ERR, POWER, "failed to open %s\n",
+                               POWER_SYSFILE_MAX_FREQ);
+               goto err;
+       }
 
-       snprintf(fullpath_base, sizeof(fullpath_base), POWER_SYSFILE_BASE_FREQ,
+       open_core_sysfs_file(&f_base, "r", POWER_SYSFILE_BASE_FREQ,
                        pi->lcore_id);
+       /* base ratio file may not exist in some kernels, so no error check */
 
-       f_base = fopen(fullpath_base, "r");
-       if (f_base == NULL) {
-               /* No sysfs base_frequency, that's OK, continue without */
-               base_ratio = 0;
+       /* read base max ratio */
+       ret = read_core_sysfs_u32(f_base_max, &base_max_ratio);
+       if (ret < 0) {
+               RTE_LOG(ERR, POWER, "Failed to read %s\n",
+                               POWER_SYSFILE_BASE_MAX_FREQ);
+               goto err;
+       }
+
+       /* base ratio may not exist */
+       if (f_base != NULL) {
+               ret = read_core_sysfs_u32(f_base, &base_ratio);
+               if (ret < 0) {
+                       RTE_LOG(ERR, POWER, "Failed to read %s\n",
+                                       POWER_SYSFILE_BASE_FREQ);
+                       goto err;
+               }
        } else {
-               s_base = fgets(buf_base, sizeof(buf_base), f_base);
-               FOPS_OR_NULL_GOTO(s_base, out);
-
-               buf_base[BUFSIZ-1] = '\0';
-               if (strlen(buf_base))
-                       /* Strip off terminating '\n' */
-                       strtok(buf_base, "\n");
-
-               base_ratio = strtoul(buf_base, NULL, POWER_CONVERT_TO_DECIMAL)
-                               / BUS_FREQ;
+               base_ratio = 0;
        }
 
        /* Add MSR read to detect turbo status */
+       if (power_rdmsr(PLATFORM_INFO, &max_non_turbo, pi->lcore_id) < 0)
+               goto err;
+       /* no errors after this point */
 
-       if (power_rdmsr(PLATFORM_INFO, &max_non_turbo, pi->lcore_id) < 0) {
-               ret_val = -1;
-               goto out;
-       }
+       /* convert ratios to bins */
+       base_max_ratio /= BUS_FREQ;
+       base_ratio /= BUS_FREQ;
+
+       /* assign file handles */
+       pi->f_cur_min = f_min;
+       pi->f_cur_max = f_max;
 
        max_non_turbo = (max_non_turbo&NON_TURBO_MASK)>>NON_TURBO_OFFSET;
 
        POWER_DEBUG_TRACE("no turbo perf %"PRIu64"\n", max_non_turbo);
 
-       pi->non_turbo_max_ratio = max_non_turbo;
+       pi->non_turbo_max_ratio = (uint32_t)max_non_turbo;
 
        /*
         * If base_frequency is reported as greater than the maximum
@@ -264,7 +218,20 @@ power_init_for_setting_freq(struct pstate_power_info *pi)
 out:
        if (f_base != NULL)
                fclose(f_base);
-       return ret_val;
+       fclose(f_base_max);
+       /* f_min and f_max are stored, no need to close */
+       return 0;
+
+err:
+       if (f_base != NULL)
+               fclose(f_base);
+       if (f_base_max != NULL)
+               fclose(f_base_max);
+       if (f_min != NULL)
+               fclose(f_min);
+       if (f_max != NULL)
+               fclose(f_max);
+       return -1;
 }
 
 static int
@@ -369,53 +336,8 @@ set_freq_internal(struct pstate_power_info *pi, uint32_t idx)
 static int
 power_set_governor_performance(struct pstate_power_info *pi)
 {
-       FILE *f;
-       int ret = -1;
-       char buf[BUFSIZ];
-       char fullpath[PATH_MAX];
-       char *s;
-       int val;
-
-       snprintf(fullpath, sizeof(fullpath), POWER_SYSFILE_GOVERNOR,
-                       pi->lcore_id);
-       f = fopen(fullpath, "rw+");
-       FOPEN_OR_ERR_RET(f, ret);
-
-       s = fgets(buf, sizeof(buf), f);
-       FOPS_OR_NULL_GOTO(s, out);
-       /* Strip off terminating '\n' */
-       strtok(buf, "\n");
-
-       /* Save the original governor */
-       rte_strscpy(pi->governor_ori, buf, sizeof(pi->governor_ori));
-
-       /* Check if current governor is performance */
-       if (strncmp(buf, POWER_GOVERNOR_PERF,
-                       sizeof(POWER_GOVERNOR_PERF)) == 0) {
-               ret = 0;
-               POWER_DEBUG_TRACE("Power management governor of lcore %u is "
-                               "already performance\n", pi->lcore_id);
-               goto out;
-       }
-
-       /* Write 'performance' to the governor */
-       val = fseek(f, 0, SEEK_SET);
-       FOPS_OR_ERR_GOTO(val, out);
-
-       val = fputs(POWER_GOVERNOR_PERF, f);
-       FOPS_OR_ERR_GOTO(val, out);
-
-       /* We need to flush to see if the fputs succeeds */
-       val = fflush(f);
-       FOPS_OR_ERR_GOTO(val, out);
-
-       ret = 0;
-       RTE_LOG(INFO, POWER, "Power management governor of lcore %u has been "
-                       "set to performance successfully\n", pi->lcore_id);
-out:
-       fclose(f);
-
-       return ret;
+       return power_set_governor(pi->lcore_id, POWER_GOVERNOR_PERF,
+                       pi->governor_ori, sizeof(pi->governor_ori));
 }
 
 /**
@@ -425,45 +347,7 @@ out:
 static int
 power_set_governor_original(struct pstate_power_info *pi)
 {
-       FILE *f;
-       int ret = -1;
-       char buf[BUFSIZ];
-       char fullpath[PATH_MAX];
-       char *s;
-       int val;
-
-       snprintf(fullpath, sizeof(fullpath), POWER_SYSFILE_GOVERNOR,
-                       pi->lcore_id);
-       f = fopen(fullpath, "rw+");
-       FOPEN_OR_ERR_RET(f, ret);
-
-       s = fgets(buf, sizeof(buf), f);
-       FOPS_OR_NULL_GOTO(s, out);
-
-       /* Check if the governor to be set is the same as current */
-       if (strncmp(buf, pi->governor_ori, sizeof(pi->governor_ori)) == 0) {
-               ret = 0;
-               POWER_DEBUG_TRACE("Power management governor of lcore %u "
-                               "has already been set to %s\n",
-                               pi->lcore_id, pi->governor_ori);
-               goto out;
-       }
-
-       /* Write back the original governor */
-       val = fseek(f, 0, SEEK_SET);
-       FOPS_OR_ERR_GOTO(val, out);
-
-       val = fputs(pi->governor_ori, f);
-       FOPS_OR_ERR_GOTO(val, out);
-
-       ret = 0;
-       RTE_LOG(INFO, POWER, "Power management governor of lcore %u "
-                       "has been set back to %s successfully\n",
-                       pi->lcore_id, pi->governor_ori);
-out:
-       fclose(f);
-
-       return ret;
+       return power_set_governor(pi->lcore_id, pi->governor_ori, NULL, 0);
 }
 
 /**
@@ -473,51 +357,42 @@ out:
 static int
 power_get_available_freqs(struct pstate_power_info *pi)
 {
-       FILE *f_min, *f_max;
+       FILE *f_min = NULL, *f_max = NULL;
        int ret = -1;
-       char *p_min, *p_max;
-       char buf_min[BUFSIZ];
-       char buf_max[BUFSIZ];
-       char fullpath_min[PATH_MAX];
-       char fullpath_max[PATH_MAX];
-       char *s_min, *s_max;
        uint32_t sys_min_freq = 0, sys_max_freq = 0, base_max_freq = 0;
        uint32_t i, num_freqs = 0;
 
-       snprintf(fullpath_max, sizeof(fullpath_max),
-                       POWER_SYSFILE_BASE_MAX_FREQ,
-                       pi->lcore_id);
-       snprintf(fullpath_min, sizeof(fullpath_min),
-                       POWER_SYSFILE_BASE_MIN_FREQ,
+       /* open all files */
+       open_core_sysfs_file(&f_max, "r", POWER_SYSFILE_BASE_MAX_FREQ,
                        pi->lcore_id);
+       if (f_max == NULL) {
+               RTE_LOG(ERR, POWER, "failed to open %s\n",
+                               POWER_SYSFILE_BASE_MAX_FREQ);
+               goto out;
+       }
 
-       f_min = fopen(fullpath_min, "r");
-       FOPEN_OR_ERR_RET(f_min, ret);
-
-       f_max = fopen(fullpath_max, "r");
-       if (f_max == NULL)
-               fclose(f_min);
-
-       FOPEN_OR_ERR_RET(f_max, ret);
-
-       s_min = fgets(buf_min, sizeof(buf_min), f_min);
-       FOPS_OR_NULL_GOTO(s_min, out);
-
-       s_max = fgets(buf_max, sizeof(buf_max), f_max);
-       FOPS_OR_NULL_GOTO(s_max, out);
-
-
-       /* Strip the line break if there is */
-       p_min = strchr(buf_min, '\n');
-       if (p_min != NULL)
-               *p_min = 0;
+       open_core_sysfs_file(&f_min, "r", POWER_SYSFILE_BASE_MIN_FREQ,
+                       pi->lcore_id);
+       if (f_min == NULL) {
+               RTE_LOG(ERR, POWER, "failed to open %s\n",
+                               POWER_SYSFILE_BASE_MIN_FREQ);
+               goto out;
+       }
 
-       p_max = strchr(buf_max, '\n');
-       if (p_max != NULL)
-               *p_max = 0;
+       /* read base ratios */
+       ret = read_core_sysfs_u32(f_max, &sys_max_freq);
+       if (ret < 0) {
+               RTE_LOG(ERR, POWER, "Failed to read %s\n",
+                               POWER_SYSFILE_BASE_MAX_FREQ);
+               goto out;
+       }
 
-       sys_min_freq = strtoul(buf_min, &p_min, POWER_CONVERT_TO_DECIMAL);
-       sys_max_freq = strtoul(buf_max, &p_max, POWER_CONVERT_TO_DECIMAL);
+       ret = read_core_sysfs_u32(f_min, &sys_min_freq);
+       if (ret < 0) {
+               RTE_LOG(ERR, POWER, "Failed to read %s\n",
+                               POWER_SYSFILE_BASE_MIN_FREQ);
+               goto out;
+       }
 
        if (sys_max_freq < sys_min_freq)
                goto out;
@@ -576,27 +451,23 @@ power_get_cur_idx(struct pstate_power_info *pi)
 {
        FILE *f_cur;
        int ret = -1;
-       char *p_cur;
-       char buf_cur[BUFSIZ];
-       char fullpath_cur[PATH_MAX];
-       char *s_cur;
        uint32_t sys_cur_freq = 0;
        unsigned int i;
 
-       snprintf(fullpath_cur, sizeof(fullpath_cur),
-                       POWER_SYSFILE_CUR_FREQ,
+       open_core_sysfs_file(&f_cur, "r", POWER_SYSFILE_CUR_FREQ,
                        pi->lcore_id);
-       f_cur = fopen(fullpath_cur, "r");
-       FOPEN_OR_ERR_RET(f_cur, ret);
-
-       /* initialize the cur_idx to matching current frequency freq index */
-       s_cur = fgets(buf_cur, sizeof(buf_cur), f_cur);
-       FOPS_OR_NULL_GOTO(s_cur, fail);
+       if (f_cur == NULL) {
+               RTE_LOG(ERR, POWER, "failed to open %s\n",
+                               POWER_SYSFILE_CUR_FREQ);
+               goto fail;
+       }
 
-       p_cur = strchr(buf_cur, '\n');
-       if (p_cur != NULL)
-               *p_cur = 0;
-       sys_cur_freq = strtoul(buf_cur, &p_cur, POWER_CONVERT_TO_DECIMAL);
+       ret = read_core_sysfs_u32(f_cur, &sys_cur_freq);
+       if (ret < 0) {
+               RTE_LOG(ERR, POWER, "Failed to read %s\n",
+                               POWER_SYSFILE_CUR_FREQ);
+               goto fail;
+       }
 
        /* convert the frequency to nearest 100000 value
         * Ex: if sys_cur_freq=1396789 then freq_conv=1400000
@@ -615,10 +486,10 @@ power_get_cur_idx(struct pstate_power_info *pi)
                }
        }
 
-       fclose(f_cur);
-       return 0;
+       ret = 0;
 fail:
-       fclose(f_cur);
+       if (f_cur != NULL)
+               fclose(f_cur);
        return ret;
 }