[dpdk-dev] [PATCH 21.08] power: refactor pstate sysfs handling

[dpdk-dev] [PATCH 21.08] power: refactor pstate sysfs handling

[Anatoly Burakov]

Currently, pstate sysfs handling code is a bit of an unmaintainable
mess, which has contributed to various errors leading to bugs. Refactor
the code in a way that makes it more maintainable and less error prone.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
 lib/librte_power/meson.build            |   7 +
 lib/librte_power/power_pstate_cpufreq.c | 355 +++++++++++++-----------
 2 files changed, 193 insertions(+), 169 deletions(-)

diff --git a/lib/librte_power/meson.build b/lib/librte_power/meson.build
index 9a2dcbfc7a..fd408ffd4c 100644
--- a/lib/librte_power/meson.build
+++ b/lib/librte_power/meson.build
@@ -5,6 +5,13 @@ if not is_linux
 	build = false
 	reason = 'only supported on Linux'
 endif
+
+# we do some snprintf magic so silence format-nonliteral
+flag_nonliteral = '-Wno-format-nonliteral'
+if cc.has_argument(flag_nonliteral)
+	cflags += flag_nonliteral
+endif
+
 sources = files('rte_power.c', 'power_acpi_cpufreq.c',
 		'power_kvm_vm.c', 'guest_channel.c',
 		'rte_power_empty_poll.c',
diff --git a/lib/librte_power/power_pstate_cpufreq.c b/lib/librte_power/power_pstate_cpufreq.c
index 3a5face4f0..db7856dadc 100644
--- a/lib/librte_power/power_pstate_cpufreq.c
+++ b/lib/librte_power/power_pstate_cpufreq.c
@@ -37,6 +37,13 @@
 		} \
 } while (0)
 
+#define FOPEN_OR_ERR_GOTO(f, label) do { \
+		if ((f) == NULL) { \
+			RTE_LOG(ERR, POWER, "File not opened\n"); \
+			goto label; \
+		} \
+} while (0)
+
 #define FOPS_OR_NULL_GOTO(ret, label) do { \
 		if ((ret) == NULL) { \
 			RTE_LOG(ERR, POWER, "fgets returns nothing\n"); \
@@ -148,93 +155,147 @@ out:	close(fd);
 	return ret;
 }
 
+static int
+open_core_sysfs_file(const char *template, unsigned int core, const char *mode,
+		FILE **f)
+{
+	char fullpath[PATH_MAX];
+	FILE *tmpf;
+
+	/* silenced -Wformat-nonliteral here */
+	snprintf(fullpath, sizeof(fullpath), template, core);
+	tmpf = fopen(fullpath, mode);
+	if (tmpf == NULL)
+		return -1;
+	*f = tmpf;
+
+	return 0;
+}
+
+static 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 */
+	if (strlen(buf))
+		strtok(buf, "\n");
+
+	fval = strtoul(buf, NULL, POWER_CONVERT_TO_DECIMAL);
+
+	/* write the value */
+	*val = fval;
+
+	return 0;
+}
+
+static 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 */
+	if (strlen(buf))
+		strtok(buf, "\n");
+
+	return 0;
+}
+
+static 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 fopen the sys file for the future setting the lcore frequency.
  */
 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");
-	if (f_base_max != NULL) {
-		s_base_max = fgets(buf_base, sizeof(buf_base), f_base_max);
-		FOPS_OR_NULL_GOTO(s_base_max, out);
-
-		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;
-		fclose(f_base_max);
-	}
-
-	snprintf(fullpath_min, sizeof(fullpath_min), POWER_SYSFILE_MIN_FREQ,
-			pi->lcore_id);
-	f_min = fopen(fullpath_min, "rw+");
-	FOPEN_OR_ERR_RET(f_min, -1);
-
-	snprintf(fullpath_max, sizeof(fullpath_max), 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;
-
-	snprintf(fullpath_base, sizeof(fullpath_base), POWER_SYSFILE_BASE_FREQ,
-			pi->lcore_id);
-
-	f_base = fopen(fullpath_base, "r");
-	FOPEN_OR_ERR_RET(f_base, -1);
-	if (f_base == NULL) {
-		/* No sysfs base_frequency, that's OK, continue without */
-		base_ratio = 0;
+	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;
+
+	/* open all files we expect to have open */
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi->lcore_id, "r",
+			&f_base_max);
+	FOPEN_OR_ERR_GOTO(f_base_max, err);
+
+	open_core_sysfs_file(POWER_SYSFILE_MIN_FREQ, pi->lcore_id, "rw+",
+			&f_min);
+	FOPEN_OR_ERR_GOTO(f_min, err);
+
+	open_core_sysfs_file(POWER_SYSFILE_MAX_FREQ, pi->lcore_id, "rw+",
+			&f_max);
+	FOPEN_OR_ERR_GOTO(f_max, err);
+
+	open_core_sysfs_file(POWER_SYSFILE_BASE_FREQ, pi->lcore_id, "r",
+			&f_base);
+	/* base ratio file may not exist in some kernels, so no error check */
+
+	/* read base max ratio */
+	ret = read_core_sysfs_u32(f_base_max, &base_max_ratio);
+	FOPS_OR_ERR_GOTO(ret, err);
+
+	/* base ratio may not exist */
+	if (f_base != NULL) {
+		ret = read_core_sysfs_u32(f_base, &base_ratio);
+		FOPS_OR_ERR_GOTO(ret, 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
@@ -260,7 +321,20 @@ 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
@@ -365,22 +439,16 @@ set_freq_internal(struct pstate_power_info *pi, uint32_t idx)
 static int
 power_set_governor_performance(struct pstate_power_info *pi)
 {
-	FILE *f;
+	FILE *f_governor = NULL;
 	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);
+	open_core_sysfs_file(POWER_SYSFILE_GOVERNOR, pi->lcore_id, "rw+",
+			&f_governor);
+	FOPEN_OR_ERR_GOTO(f_governor, out);
 
-	s = fgets(buf, sizeof(buf), f);
-	FOPS_OR_NULL_GOTO(s, out);
-	/* Strip off terminating '\n' */
-	strtok(buf, "\n");
+	ret = read_core_sysfs_s(f_governor, buf, sizeof(buf));
+	FOPS_OR_ERR_GOTO(ret, out);
 
 	/* Save the original governor */
 	rte_strscpy(pi->governor_ori, buf, sizeof(pi->governor_ori));
@@ -395,21 +463,15 @@ power_set_governor_performance(struct pstate_power_info *pi)
 	}
 
 	/* 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 = write_core_sysfs_s(f_governor, POWER_GOVERNOR_PERF);
+	FOPS_OR_ERR_GOTO(ret, 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);
+	if (f_governor != NULL)
+		fclose(f_governor);
 
 	return ret;
 }
@@ -421,20 +483,16 @@ power_set_governor_performance(struct pstate_power_info *pi)
 static int
 power_set_governor_original(struct pstate_power_info *pi)
 {
-	FILE *f;
+	FILE *f_governor = NULL;
 	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);
+	open_core_sysfs_file(POWER_SYSFILE_GOVERNOR, pi->lcore_id, "rw+",
+			&f_governor);
+	FOPEN_OR_ERR_GOTO(f_governor, out);
 
-	s = fgets(buf, sizeof(buf), f);
-	FOPS_OR_NULL_GOTO(s, out);
+	ret = read_core_sysfs_s(f_governor, buf, sizeof(buf));
+	FOPS_OR_ERR_GOTO(ret, out);
 
 	/* Check if the governor to be set is the same as current */
 	if (strncmp(buf, pi->governor_ori, sizeof(pi->governor_ori)) == 0) {
@@ -446,19 +504,16 @@ power_set_governor_original(struct pstate_power_info *pi)
 	}
 
 	/* 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 = write_core_sysfs_s(f_governor, pi->governor_ori);
+	FOPS_OR_ERR_GOTO(ret, 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);
-
+	if (f_governor != NULL)
+		fclose(f_governor);
 	return ret;
 }
 
@@ -469,51 +524,26 @@ power_set_governor_original(struct pstate_power_info *pi)
 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,
-			pi->lcore_id);
+	/* open all files */
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi->lcore_id, "r",
+			&f_max);
+	FOPEN_OR_ERR_GOTO(f_max, out);
 
-	f_min = fopen(fullpath_min, "r");
-	FOPEN_OR_ERR_RET(f_min, ret);
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MIN_FREQ, pi->lcore_id, "r",
+			     &f_min);
+	FOPEN_OR_ERR_GOTO(f_max, out);
 
-	f_max = fopen(fullpath_max, "r");
-	if (f_max == NULL)
-		fclose(f_min);
+	/* read base ratios */
+	ret = read_core_sysfs_u32(f_max, &sys_max_freq);
+	FOPS_OR_ERR_GOTO(ret, out);
 
-	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;
-
-	p_max = strchr(buf_max, '\n');
-	if (p_max != NULL)
-		*p_max = 0;
-
-	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);
+	FOPS_OR_ERR_GOTO(ret, out);
 
 	if (sys_max_freq < sys_min_freq)
 		goto out;
@@ -572,27 +602,14 @@ 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,
-			pi->lcore_id);
-	f_cur = fopen(fullpath_cur, "r");
-	FOPEN_OR_ERR_RET(f_cur, ret);
+	open_core_sysfs_file(POWER_SYSFILE_CUR_FREQ, pi->lcore_id, "r", &f_cur);
+	FOPEN_OR_ERR_GOTO(f_cur, fail);
 
-	/* 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);
-
-	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);
+	FOPS_OR_ERR_GOTO(ret, fail);
 
 	/* convert the frequency to nearest 100000 value
 	 * Ex: if sys_cur_freq=1396789 then freq_conv=1400000
@@ -611,10 +628,10 @@ 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;
 }
 
-- 
2.25.1

[dpdk-dev] [21.08 v2] power: refactor pstate sysfs handling

[Anatoly Burakov]

Currently, pstate sysfs handling code is a bit of an unmaintainable
mess, which has contributed to various errors leading to bugs. Refactor
the code in a way that makes it more maintainable and less error prone.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
 lib/librte_power/meson.build            |   7 +
 lib/librte_power/power_pstate_cpufreq.c | 355 +++++++++++++-----------
 2 files changed, 193 insertions(+), 169 deletions(-)

diff --git a/lib/librte_power/meson.build b/lib/librte_power/meson.build
index 9a2dcbfc7a..fd408ffd4c 100644
--- a/lib/librte_power/meson.build
+++ b/lib/librte_power/meson.build
@@ -5,6 +5,13 @@ if not is_linux
 	build = false
 	reason = 'only supported on Linux'
 endif
+
+# we do some snprintf magic so silence format-nonliteral
+flag_nonliteral = '-Wno-format-nonliteral'
+if cc.has_argument(flag_nonliteral)
+	cflags += flag_nonliteral
+endif
+
 sources = files('rte_power.c', 'power_acpi_cpufreq.c',
 		'power_kvm_vm.c', 'guest_channel.c',
 		'rte_power_empty_poll.c',
diff --git a/lib/librte_power/power_pstate_cpufreq.c b/lib/librte_power/power_pstate_cpufreq.c
index 1cb0e4d917..db7856dadc 100644
--- a/lib/librte_power/power_pstate_cpufreq.c
+++ b/lib/librte_power/power_pstate_cpufreq.c
@@ -37,6 +37,13 @@
 		} \
 } while (0)
 
+#define FOPEN_OR_ERR_GOTO(f, label) do { \
+		if ((f) == NULL) { \
+			RTE_LOG(ERR, POWER, "File not opened\n"); \
+			goto label; \
+		} \
+} while (0)
+
 #define FOPS_OR_NULL_GOTO(ret, label) do { \
 		if ((ret) == NULL) { \
 			RTE_LOG(ERR, POWER, "fgets returns nothing\n"); \
@@ -148,93 +155,147 @@ out:	close(fd);
 	return ret;
 }
 
+static int
+open_core_sysfs_file(const char *template, unsigned int core, const char *mode,
+		FILE **f)
+{
+	char fullpath[PATH_MAX];
+	FILE *tmpf;
+
+	/* silenced -Wformat-nonliteral here */
+	snprintf(fullpath, sizeof(fullpath), template, core);
+	tmpf = fopen(fullpath, mode);
+	if (tmpf == NULL)
+		return -1;
+	*f = tmpf;
+
+	return 0;
+}
+
+static 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 */
+	if (strlen(buf))
+		strtok(buf, "\n");
+
+	fval = strtoul(buf, NULL, POWER_CONVERT_TO_DECIMAL);
+
+	/* write the value */
+	*val = fval;
+
+	return 0;
+}
+
+static 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 */
+	if (strlen(buf))
+		strtok(buf, "\n");
+
+	return 0;
+}
+
+static 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 fopen the sys file for the future setting the lcore frequency.
  */
 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);
-		FOPS_OR_NULL_GOTO(s_base_max, out);
-
-		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;
-	}
-
-	snprintf(fullpath_min, sizeof(fullpath_min), POWER_SYSFILE_MIN_FREQ,
-			pi->lcore_id);
-	f_min = fopen(fullpath_min, "rw+");
-	FOPEN_OR_ERR_RET(f_min, -1);
-
-	snprintf(fullpath_max, sizeof(fullpath_max), 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;
-
-	snprintf(fullpath_base, sizeof(fullpath_base), POWER_SYSFILE_BASE_FREQ,
-			pi->lcore_id);
-
-	f_base = fopen(fullpath_base, "r");
-	if (f_base == NULL) {
-		/* No sysfs base_frequency, that's OK, continue without */
-		base_ratio = 0;
+	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;
+
+	/* open all files we expect to have open */
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi->lcore_id, "r",
+			&f_base_max);
+	FOPEN_OR_ERR_GOTO(f_base_max, err);
+
+	open_core_sysfs_file(POWER_SYSFILE_MIN_FREQ, pi->lcore_id, "rw+",
+			&f_min);
+	FOPEN_OR_ERR_GOTO(f_min, err);
+
+	open_core_sysfs_file(POWER_SYSFILE_MAX_FREQ, pi->lcore_id, "rw+",
+			&f_max);
+	FOPEN_OR_ERR_GOTO(f_max, err);
+
+	open_core_sysfs_file(POWER_SYSFILE_BASE_FREQ, pi->lcore_id, "r",
+			&f_base);
+	/* base ratio file may not exist in some kernels, so no error check */
+
+	/* read base max ratio */
+	ret = read_core_sysfs_u32(f_base_max, &base_max_ratio);
+	FOPS_OR_ERR_GOTO(ret, err);
+
+	/* base ratio may not exist */
+	if (f_base != NULL) {
+		ret = read_core_sysfs_u32(f_base, &base_ratio);
+		FOPS_OR_ERR_GOTO(ret, 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;
-		fclose(f_base);
+		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
@@ -260,7 +321,20 @@ 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
@@ -365,22 +439,16 @@ set_freq_internal(struct pstate_power_info *pi, uint32_t idx)
 static int
 power_set_governor_performance(struct pstate_power_info *pi)
 {
-	FILE *f;
+	FILE *f_governor = NULL;
 	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);
+	open_core_sysfs_file(POWER_SYSFILE_GOVERNOR, pi->lcore_id, "rw+",
+			&f_governor);
+	FOPEN_OR_ERR_GOTO(f_governor, out);
 
-	s = fgets(buf, sizeof(buf), f);
-	FOPS_OR_NULL_GOTO(s, out);
-	/* Strip off terminating '\n' */
-	strtok(buf, "\n");
+	ret = read_core_sysfs_s(f_governor, buf, sizeof(buf));
+	FOPS_OR_ERR_GOTO(ret, out);
 
 	/* Save the original governor */
 	rte_strscpy(pi->governor_ori, buf, sizeof(pi->governor_ori));
@@ -395,21 +463,15 @@ power_set_governor_performance(struct pstate_power_info *pi)
 	}
 
 	/* 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 = write_core_sysfs_s(f_governor, POWER_GOVERNOR_PERF);
+	FOPS_OR_ERR_GOTO(ret, 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);
+	if (f_governor != NULL)
+		fclose(f_governor);
 
 	return ret;
 }
@@ -421,20 +483,16 @@ power_set_governor_performance(struct pstate_power_info *pi)
 static int
 power_set_governor_original(struct pstate_power_info *pi)
 {
-	FILE *f;
+	FILE *f_governor = NULL;
 	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);
+	open_core_sysfs_file(POWER_SYSFILE_GOVERNOR, pi->lcore_id, "rw+",
+			&f_governor);
+	FOPEN_OR_ERR_GOTO(f_governor, out);
 
-	s = fgets(buf, sizeof(buf), f);
-	FOPS_OR_NULL_GOTO(s, out);
+	ret = read_core_sysfs_s(f_governor, buf, sizeof(buf));
+	FOPS_OR_ERR_GOTO(ret, out);
 
 	/* Check if the governor to be set is the same as current */
 	if (strncmp(buf, pi->governor_ori, sizeof(pi->governor_ori)) == 0) {
@@ -446,19 +504,16 @@ power_set_governor_original(struct pstate_power_info *pi)
 	}
 
 	/* 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 = write_core_sysfs_s(f_governor, pi->governor_ori);
+	FOPS_OR_ERR_GOTO(ret, 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);
-
+	if (f_governor != NULL)
+		fclose(f_governor);
 	return ret;
 }
 
@@ -469,51 +524,26 @@ power_set_governor_original(struct pstate_power_info *pi)
 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,
-			pi->lcore_id);
+	/* open all files */
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi->lcore_id, "r",
+			&f_max);
+	FOPEN_OR_ERR_GOTO(f_max, out);
 
-	f_min = fopen(fullpath_min, "r");
-	FOPEN_OR_ERR_RET(f_min, ret);
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MIN_FREQ, pi->lcore_id, "r",
+			     &f_min);
+	FOPEN_OR_ERR_GOTO(f_max, out);
 
-	f_max = fopen(fullpath_max, "r");
-	if (f_max == NULL)
-		fclose(f_min);
+	/* read base ratios */
+	ret = read_core_sysfs_u32(f_max, &sys_max_freq);
+	FOPS_OR_ERR_GOTO(ret, out);
 
-	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;
-
-	p_max = strchr(buf_max, '\n');
-	if (p_max != NULL)
-		*p_max = 0;
-
-	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);
+	FOPS_OR_ERR_GOTO(ret, out);
 
 	if (sys_max_freq < sys_min_freq)
 		goto out;
@@ -572,27 +602,14 @@ 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,
-			pi->lcore_id);
-	f_cur = fopen(fullpath_cur, "r");
-	FOPEN_OR_ERR_RET(f_cur, ret);
+	open_core_sysfs_file(POWER_SYSFILE_CUR_FREQ, pi->lcore_id, "r", &f_cur);
+	FOPEN_OR_ERR_GOTO(f_cur, fail);
 
-	/* 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);
-
-	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);
+	FOPS_OR_ERR_GOTO(ret, fail);
 
 	/* convert the frequency to nearest 100000 value
 	 * Ex: if sys_cur_freq=1396789 then freq_conv=1400000
@@ -611,10 +628,10 @@ 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;
 }
 
-- 
2.25.1

Re: [dpdk-dev] [PATCH 21.08] power: refactor pstate sysfs handling

[Stephen Hemminger]

On Thu,  1 Apr 2021 15:05:17 +0000
Anatoly Burakov <anatoly.burakov@intel.com> wrote:

>  
> +#define FOPEN_OR_ERR_GOTO(f, label) do { \
> +		if ((f) == NULL) { \
> +			RTE_LOG(ERR, POWER, "File not opened\n"); \
> +			goto label; \
> +		} \
> +} while (0)
> +

I am not a fan of macros like this that have gotos.
It is clearer to just open code it.

Re: [dpdk-dev] [PATCH 21.08] power: refactor pstate sysfs handling

[Stephen Hemminger]

On Thu,  1 Apr 2021 15:05:17 +0000
Anatoly Burakov <anatoly.burakov@intel.com> wrote:

> +	/* fgets puts null terminator in, but do this just in case */
> +	buf[BUFSIZ - 1] = '\0';
> +
> +	/* strip off any terminating newlines */
> +	if (strlen(buf))
> +		strtok(buf, "\n");

Why not the simpler/shorter
	strchrnul(buf, '\n') = '\0';

Re: [dpdk-dev] [PATCH 21.08] power: refactor pstate sysfs handling

[Burakov, Anatoly]

On 02-Apr-21 6:46 PM, Stephen Hemminger wrote:
> On Thu,  1 Apr 2021 15:05:17 +0000
> Anatoly Burakov <anatoly.burakov@intel.com> wrote:
> 
>> +	/* fgets puts null terminator in, but do this just in case */
>> +	buf[BUFSIZ - 1] = '\0';
>> +
>> +	/* strip off any terminating newlines */
>> +	if (strlen(buf))
>> +		strtok(buf, "\n");
> 
> Why not the simpler/shorter
> 	strchrnul(buf, '\n') = '\0';
> 

How many more string functions are there that i don't know about :D

-- 
Thanks,
Anatoly

Re: [dpdk-dev] [PATCH 21.08] power: refactor pstate sysfs handling

[Burakov, Anatoly]

On 02-Apr-21 6:45 PM, Stephen Hemminger wrote:
> On Thu,  1 Apr 2021 15:05:17 +0000
> Anatoly Burakov <anatoly.burakov@intel.com> wrote:
> 
>>   
>> +#define FOPEN_OR_ERR_GOTO(f, label) do { \
>> +		if ((f) == NULL) { \
>> +			RTE_LOG(ERR, POWER, "File not opened\n"); \
>> +			goto label; \
>> +		} \
>> +} while (0)
>> +
> 
> I am not a fan of macros like this that have gotos.
> It is clearer to just open code it.
> 

Well, it's keeping consistent style with the rest of the file. If we are 
to remove these, ideally we should just replace usage of all of them.

-- 
Thanks,
Anatoly

[dpdk-dev] [21.08 PATCH v3 1/1] power: refactor pstate sysfs handling

[Anatoly Burakov]

Currently, pstate sysfs handling code is a bit of an unmaintainable
mess, which has contributed to various errors leading to bugs. Refactor
the code in a way that makes it more maintainable and less error prone.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
 lib/power/meson.build            |   7 +
 lib/power/power_pstate_cpufreq.c | 357 ++++++++++++++++---------------
 2 files changed, 191 insertions(+), 173 deletions(-)

diff --git a/lib/power/meson.build b/lib/power/meson.build
index a2cc9fe2ef..85324d48d2 100644
--- a/lib/power/meson.build
+++ b/lib/power/meson.build
@@ -5,6 +5,13 @@ if not is_linux
     build = false
     reason = 'only supported on Linux'
 endif
+
+# we do some snprintf magic so silence format-nonliteral
+flag_nonliteral = '-Wno-format-nonliteral'
+if cc.has_argument(flag_nonliteral)
+	cflags += flag_nonliteral
+endif
+
 sources = files(
         'guest_channel.c',
         'power_acpi_cpufreq.c',
diff --git a/lib/power/power_pstate_cpufreq.c b/lib/power/power_pstate_cpufreq.c
index 2cfc54acf3..4357ac4920 100644
--- a/lib/power/power_pstate_cpufreq.c
+++ b/lib/power/power_pstate_cpufreq.c
@@ -37,6 +37,13 @@
 		} \
 } while (0)
 
+#define FOPEN_OR_ERR_GOTO(f, label) do { \
+		if ((f) == NULL) { \
+			RTE_LOG(ERR, POWER, "File not opened\n"); \
+			goto label; \
+		} \
+} while (0)
+
 #define FOPS_OR_NULL_GOTO(ret, label) do { \
 		if ((ret) == NULL) { \
 			RTE_LOG(ERR, POWER, "fgets returns nothing\n"); \
@@ -148,97 +155,145 @@ out:	close(fd);
 	return ret;
 }
 
+static int
+open_core_sysfs_file(const char *template, unsigned int core, const char *mode,
+		FILE **f)
+{
+	char fullpath[PATH_MAX];
+	FILE *tmpf;
+
+	/* silenced -Wformat-nonliteral here */
+	snprintf(fullpath, sizeof(fullpath), template, core);
+	tmpf = fopen(fullpath, mode);
+	if (tmpf == NULL)
+		return -1;
+	*f = tmpf;
+
+	return 0;
+}
+
+static 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;
+}
+
+static 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;
+}
+
+static 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 fopen the sys file for the future setting the lcore frequency.
  */
 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);
-
-		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;
-	}
-
-	snprintf(fullpath_min, sizeof(fullpath_min), POWER_SYSFILE_MIN_FREQ,
-			pi->lcore_id);
-	f_min = fopen(fullpath_min, "rw+");
-	FOPEN_OR_ERR_RET(f_min, -1);
-
-	snprintf(fullpath_max, sizeof(fullpath_max), 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;
-
-	snprintf(fullpath_base, sizeof(fullpath_base), POWER_SYSFILE_BASE_FREQ,
-			pi->lcore_id);
-
-	f_base = fopen(fullpath_base, "r");
-	if (f_base == NULL) {
-		/* No sysfs base_frequency, that's OK, continue without */
-		base_ratio = 0;
+	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;
+
+	/* open all files we expect to have open */
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi->lcore_id, "r",
+			&f_base_max);
+	FOPEN_OR_ERR_GOTO(f_base_max, err);
+
+	open_core_sysfs_file(POWER_SYSFILE_MIN_FREQ, pi->lcore_id, "rw+",
+			&f_min);
+	FOPEN_OR_ERR_GOTO(f_min, err);
+
+	open_core_sysfs_file(POWER_SYSFILE_MAX_FREQ, pi->lcore_id, "rw+",
+			&f_max);
+	FOPEN_OR_ERR_GOTO(f_max, err);
+
+	open_core_sysfs_file(POWER_SYSFILE_BASE_FREQ, pi->lcore_id, "r",
+			&f_base);
+	/* base ratio file may not exist in some kernels, so no error check */
+
+	/* read base max ratio */
+	ret = read_core_sysfs_u32(f_base_max, &base_max_ratio);
+	FOPS_OR_ERR_GOTO(ret, err);
+
+	/* base ratio may not exist */
+	if (f_base != NULL) {
+		ret = read_core_sysfs_u32(f_base, &base_ratio);
+		FOPS_OR_ERR_GOTO(ret, 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 +319,20 @@ 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
@@ -369,22 +437,16 @@ set_freq_internal(struct pstate_power_info *pi, uint32_t idx)
 static int
 power_set_governor_performance(struct pstate_power_info *pi)
 {
-	FILE *f;
+	FILE *f_governor = NULL;
 	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);
+	open_core_sysfs_file(POWER_SYSFILE_GOVERNOR, pi->lcore_id, "rw+",
+			&f_governor);
+	FOPEN_OR_ERR_GOTO(f_governor, out);
 
-	s = fgets(buf, sizeof(buf), f);
-	FOPS_OR_NULL_GOTO(s, out);
-	/* Strip off terminating '\n' */
-	strtok(buf, "\n");
+	ret = read_core_sysfs_s(f_governor, buf, sizeof(buf));
+	FOPS_OR_ERR_GOTO(ret, out);
 
 	/* Save the original governor */
 	rte_strscpy(pi->governor_ori, buf, sizeof(pi->governor_ori));
@@ -399,21 +461,15 @@ power_set_governor_performance(struct pstate_power_info *pi)
 	}
 
 	/* 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 = write_core_sysfs_s(f_governor, POWER_GOVERNOR_PERF);
+	FOPS_OR_ERR_GOTO(ret, 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);
+	if (f_governor != NULL)
+		fclose(f_governor);
 
 	return ret;
 }
@@ -425,20 +481,16 @@ power_set_governor_performance(struct pstate_power_info *pi)
 static int
 power_set_governor_original(struct pstate_power_info *pi)
 {
-	FILE *f;
+	FILE *f_governor = NULL;
 	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);
+	open_core_sysfs_file(POWER_SYSFILE_GOVERNOR, pi->lcore_id, "rw+",
+			&f_governor);
+	FOPEN_OR_ERR_GOTO(f_governor, out);
 
-	s = fgets(buf, sizeof(buf), f);
-	FOPS_OR_NULL_GOTO(s, out);
+	ret = read_core_sysfs_s(f_governor, buf, sizeof(buf));
+	FOPS_OR_ERR_GOTO(ret, out);
 
 	/* Check if the governor to be set is the same as current */
 	if (strncmp(buf, pi->governor_ori, sizeof(pi->governor_ori)) == 0) {
@@ -450,19 +502,16 @@ power_set_governor_original(struct pstate_power_info *pi)
 	}
 
 	/* 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 = write_core_sysfs_s(f_governor, pi->governor_ori);
+	FOPS_OR_ERR_GOTO(ret, 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);
-
+	if (f_governor != NULL)
+		fclose(f_governor);
 	return ret;
 }
 
@@ -473,51 +522,26 @@ power_set_governor_original(struct pstate_power_info *pi)
 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,
-			pi->lcore_id);
+	/* open all files */
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi->lcore_id, "r",
+			&f_max);
+	FOPEN_OR_ERR_GOTO(f_max, out);
 
-	f_min = fopen(fullpath_min, "r");
-	FOPEN_OR_ERR_RET(f_min, ret);
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MIN_FREQ, pi->lcore_id, "r",
+			     &f_min);
+	FOPEN_OR_ERR_GOTO(f_max, out);
 
-	f_max = fopen(fullpath_max, "r");
-	if (f_max == NULL)
-		fclose(f_min);
+	/* read base ratios */
+	ret = read_core_sysfs_u32(f_max, &sys_max_freq);
+	FOPS_OR_ERR_GOTO(ret, out);
 
-	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;
-
-	p_max = strchr(buf_max, '\n');
-	if (p_max != NULL)
-		*p_max = 0;
-
-	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);
+	FOPS_OR_ERR_GOTO(ret, out);
 
 	if (sys_max_freq < sys_min_freq)
 		goto out;
@@ -576,27 +600,14 @@ 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,
-			pi->lcore_id);
-	f_cur = fopen(fullpath_cur, "r");
-	FOPEN_OR_ERR_RET(f_cur, ret);
+	open_core_sysfs_file(POWER_SYSFILE_CUR_FREQ, pi->lcore_id, "r", &f_cur);
+	FOPEN_OR_ERR_GOTO(f_cur, fail);
 
-	/* 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);
-
-	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);
+	FOPS_OR_ERR_GOTO(ret, fail);
 
 	/* convert the frequency to nearest 100000 value
 	 * Ex: if sys_cur_freq=1396789 then freq_conv=1400000
@@ -615,10 +626,10 @@ 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;
 }
 
-- 
2.25.1

[dpdk-dev] [21.08 PATCH v4 1/2] power: don't use rte prefix in internal code

[Anatoly Burakov]

Currently, ACPI code uses rte_power_info as the struct name, which
gives the appearance that this is an externally visible API. Fix to
use internal namespace.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
 lib/power/power_acpi_cpufreq.c | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/lib/power/power_acpi_cpufreq.c b/lib/power/power_acpi_cpufreq.c
index d028a9947f..1b8c69cc8b 100644
--- a/lib/power/power_acpi_cpufreq.c
+++ b/lib/power/power_acpi_cpufreq.c
@@ -78,7 +78,7 @@ enum power_state {
 /**
  * Power info per lcore.
  */
-struct rte_power_info {
+struct acpi_power_info {
 	unsigned int lcore_id;                   /**< Logical core id */
 	uint32_t freqs[RTE_MAX_LCORE_FREQS]; /**< Frequency array */
 	uint32_t nb_freqs;                   /**< number of available freqs */
@@ -90,14 +90,14 @@ struct rte_power_info {
 	uint16_t turbo_enable;               /**< Turbo Boost enable/disable */
 } __rte_cache_aligned;
 
-static struct rte_power_info lcore_power_info[RTE_MAX_LCORE];
+static struct acpi_power_info lcore_power_info[RTE_MAX_LCORE];
 
 /**
  * It is to set specific freq for specific logical core, according to the index
  * of supported frequencies.
  */
 static int
-set_freq_internal(struct rte_power_info *pi, uint32_t idx)
+set_freq_internal(struct acpi_power_info *pi, uint32_t idx)
 {
 	if (idx >= RTE_MAX_LCORE_FREQS || idx >= pi->nb_freqs) {
 		RTE_LOG(ERR, POWER, "Invalid frequency index %u, which "
@@ -133,7 +133,7 @@ set_freq_internal(struct rte_power_info *pi, uint32_t idx)
  * governor will be saved for rolling back.
  */
 static int
-power_set_governor_userspace(struct rte_power_info *pi)
+power_set_governor_userspace(struct acpi_power_info *pi)
 {
 	FILE *f;
 	int ret = -1;
@@ -189,7 +189,7 @@ power_set_governor_userspace(struct rte_power_info *pi)
  * sys file.
  */
 static int
-power_get_available_freqs(struct rte_power_info *pi)
+power_get_available_freqs(struct acpi_power_info *pi)
 {
 	FILE *f;
 	int ret = -1, i, count;
@@ -259,7 +259,7 @@ power_get_available_freqs(struct rte_power_info *pi)
  * It is to fopen the sys file for the future setting the lcore frequency.
  */
 static int
-power_init_for_setting_freq(struct rte_power_info *pi)
+power_init_for_setting_freq(struct acpi_power_info *pi)
 {
 	FILE *f;
 	char fullpath[PATH_MAX];
@@ -299,7 +299,7 @@ power_acpi_cpufreq_check_supported(void)
 int
 power_acpi_cpufreq_init(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 	uint32_t exp_state;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
@@ -374,7 +374,7 @@ power_acpi_cpufreq_init(unsigned int lcore_id)
  * needed by writing the sys file.
  */
 static int
-power_set_governor_original(struct rte_power_info *pi)
+power_set_governor_original(struct acpi_power_info *pi)
 {
 	FILE *f;
 	int ret = -1;
@@ -420,7 +420,7 @@ power_set_governor_original(struct rte_power_info *pi)
 int
 power_acpi_cpufreq_exit(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 	uint32_t exp_state;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
@@ -475,7 +475,7 @@ power_acpi_cpufreq_exit(unsigned int lcore_id)
 uint32_t
 power_acpi_cpufreq_freqs(unsigned int lcore_id, uint32_t *freqs, uint32_t num)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -522,7 +522,7 @@ power_acpi_cpufreq_set_freq(unsigned int lcore_id, uint32_t index)
 int
 power_acpi_cpufreq_freq_down(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -540,7 +540,7 @@ power_acpi_cpufreq_freq_down(unsigned int lcore_id)
 int
 power_acpi_cpufreq_freq_up(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -581,7 +581,7 @@ power_acpi_cpufreq_freq_max(unsigned int lcore_id)
 int
 power_acpi_cpufreq_freq_min(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -598,7 +598,7 @@ power_acpi_cpufreq_freq_min(unsigned int lcore_id)
 int
 power_acpi_turbo_status(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -614,7 +614,7 @@ power_acpi_turbo_status(unsigned int lcore_id)
 int
 power_acpi_enable_turbo(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -647,7 +647,7 @@ power_acpi_enable_turbo(unsigned int lcore_id)
 int
 power_acpi_disable_turbo(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -674,7 +674,7 @@ power_acpi_disable_turbo(unsigned int lcore_id)
 int power_acpi_get_capabilities(unsigned int lcore_id,
 		struct rte_power_core_capabilities *caps)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
-- 
2.25.1

[dpdk-dev] [21.08 PATCH v4 2/2] power: refactor pstate and acpi code

[Anatoly Burakov]

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>
---
 lib/power/meson.build            |   7 +
 lib/power/power_acpi_cpufreq.c   | 178 +++--------------
 lib/power/power_common.c         | 133 +++++++++++++
 lib/power/power_common.h         |  46 +++++
 lib/power/power_pstate_cpufreq.c | 332 ++++++++-----------------------
 5 files changed, 293 insertions(+), 403 deletions(-)

diff --git a/lib/power/meson.build b/lib/power/meson.build
index a2cc9fe2ef..85324d48d2 100644
--- a/lib/power/meson.build
+++ b/lib/power/meson.build
@@ -5,6 +5,13 @@ if not is_linux
     build = false
     reason = 'only supported on Linux'
 endif
+
+# we do some snprintf magic so silence format-nonliteral
+flag_nonliteral = '-Wno-format-nonliteral'
+if cc.has_argument(flag_nonliteral)
+	cflags += flag_nonliteral
+endif
+
 sources = files(
         'guest_channel.c',
         'power_acpi_cpufreq.c',
diff --git a/lib/power/power_acpi_cpufreq.c b/lib/power/power_acpi_cpufreq.c
index 1b8c69cc8b..97f1d302c9 100644
--- a/lib/power/power_acpi_cpufreq.c
+++ b/lib/power/power_acpi_cpufreq.c
@@ -19,41 +19,10 @@
 #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 ret;
+	return power_set_governor(pi->lcore_id, POWER_GOVERNOR_USERSPACE,
+			pi->governor_ori, sizeof(pi->governor_ori));
+}
+
+/**
+ * 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 +129,14 @@ 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);
+	open_core_sysfs_file(POWER_SYSFILE_AVAIL_FREQ, pi->lcore_id, "r",
+			&f);
+	FOPEN_OR_ERR_GOTO(f, out);
 
-	s = fgets(buf, sizeof(buf), f);
-	FOPS_OR_NULL_GOTO(s, 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));
+	FOPS_OR_ERR_GOTO(ret, out);
 
 	/* Split string into at most RTE_MAX_LCORE_FREQS frequencies */
 	count = rte_strsplit(buf, sizeof(buf), freqs,
@@ -250,7 +176,8 @@ 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 +189,16 @@ 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(POWER_SYSFILE_SETSPEED, pi->lcore_id, "r",
+			&f);
+	FOPEN_OR_ERR_GOTO(f, err);
 
-	s = fgets(buf, sizeof(buf), f);
-	FOPS_OR_NULL_GOTO(s, out);
+	ret = read_core_sysfs_s(f, buf, sizeof(buf));
+	FOPS_OR_ERR_GOTO(ret, err);
 
 	freq = strtoul(buf, NULL, POWER_CONVERT_TO_DECIMAL);
 	for (i = 0; i < pi->nb_freqs; i++) {
@@ -284,8 +209,9 @@ power_init_for_setting_freq(struct acpi_power_info *pi)
 		}
 	}
 
-out:
-	fclose(f);
+err:
+	if (f != NULL)
+		fclose(f);
 
 	return -1;
 }
@@ -369,54 +295,6 @@ power_acpi_cpufreq_init(unsigned int lcore_id)
 	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)
 {
diff --git a/lib/power/power_common.c b/lib/power/power_common.c
index 67e3318ec7..f06e9e5fa9 100644
--- a/lib/power/power_common.c
+++ b/lib/power/power_common.c
@@ -3,13 +3,20 @@
  */
 
 #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)
@@ -58,3 +65,129 @@ cpufreq_check_scaling_driver(const char *driver_name)
 	 */
 	return 1;
 }
+
+int
+open_core_sysfs_file(const char *template, unsigned int core, const char *mode,
+		FILE **f)
+{
+	char fullpath[PATH_MAX];
+	FILE *tmpf;
+
+	/* silenced -Wformat-nonliteral here */
+	snprintf(fullpath, sizeof(fullpath), template, core);
+	tmpf = fopen(fullpath, mode);
+	if (tmpf == NULL)
+		return -1;
+	*f = tmpf;
+
+	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(POWER_SYSFILE_GOVERNOR, lcore_id, "rw+", &f_governor);
+	FOPEN_OR_ERR_GOTO(f_governor, out);
+
+	ret = read_core_sysfs_s(f_governor, buf, sizeof(buf));
+	FOPS_OR_ERR_GOTO(ret, 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);
+	FOPS_OR_ERR_GOTO(ret, 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;
+}
diff --git a/lib/power/power_common.h b/lib/power/power_common.h
index fab3ca995a..729ae8cbf4 100644
--- a/lib/power/power_common.h
+++ b/lib/power/power_common.h
@@ -5,9 +5,55 @@
 #ifndef _POWER_COMMON_H_
 #define _POWER_COMMON_H_
 
+#include <inttypes.h>
+
 #define RTE_POWER_INVALID_FREQ_INDEX (~0)
 
+
+#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 FOPEN_OR_ERR_GOTO(f, label) do { \
+		if ((f) == NULL) { \
+			RTE_LOG(ERR, POWER, "File not opened\n"); \
+			goto label; \
+		} \
+} 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)
+
 /* 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(const char *template, unsigned int core,
+			 const char *mode, FILE **f);
+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_ */
diff --git a/lib/power/power_pstate_cpufreq.c b/lib/power/power_pstate_cpufreq.c
index 2cfc54acf3..2a365988a9 100644
--- a/lib/power/power_pstate_cpufreq.c
+++ b/lib/power/power_pstate_cpufreq.c
@@ -21,46 +21,13 @@
 #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 +121,58 @@ 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);
-
-		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;
-	}
-
-	snprintf(fullpath_min, sizeof(fullpath_min), POWER_SYSFILE_MIN_FREQ,
-			pi->lcore_id);
-	f_min = fopen(fullpath_min, "rw+");
-	FOPEN_OR_ERR_RET(f_min, -1);
-
-	snprintf(fullpath_max, sizeof(fullpath_max), 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;
-
-	snprintf(fullpath_base, sizeof(fullpath_base), POWER_SYSFILE_BASE_FREQ,
-			pi->lcore_id);
-
-	f_base = fopen(fullpath_base, "r");
-	if (f_base == NULL) {
-		/* No sysfs base_frequency, that's OK, continue without */
-		base_ratio = 0;
+	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;
+
+	/* open all files we expect to have open */
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi->lcore_id, "r",
+			&f_base_max);
+	FOPEN_OR_ERR_GOTO(f_base_max, err);
+
+	open_core_sysfs_file(POWER_SYSFILE_MIN_FREQ, pi->lcore_id, "rw+",
+			&f_min);
+	FOPEN_OR_ERR_GOTO(f_min, err);
+
+	open_core_sysfs_file(POWER_SYSFILE_MAX_FREQ, pi->lcore_id, "rw+",
+			&f_max);
+	FOPEN_OR_ERR_GOTO(f_max, err);
+
+	open_core_sysfs_file(POWER_SYSFILE_BASE_FREQ, pi->lcore_id, "r",
+			&f_base);
+	/* base ratio file may not exist in some kernels, so no error check */
+
+	/* read base max ratio */
+	ret = read_core_sysfs_u32(f_base_max, &base_max_ratio);
+	FOPS_OR_ERR_GOTO(ret, err);
+
+	/* base ratio may not exist */
+	if (f_base != NULL) {
+		ret = read_core_sysfs_u32(f_base, &base_ratio);
+		FOPS_OR_ERR_GOTO(ret, 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 +198,20 @@ 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 +316,8 @@ 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 +327,7 @@ power_set_governor_performance(struct pstate_power_info *pi)
 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 +337,26 @@ power_set_governor_original(struct pstate_power_info *pi)
 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,
-			pi->lcore_id);
+	/* open all files */
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi->lcore_id, "r",
+			&f_max);
+	FOPEN_OR_ERR_GOTO(f_max, out);
 
-	f_min = fopen(fullpath_min, "r");
-	FOPEN_OR_ERR_RET(f_min, ret);
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MIN_FREQ, pi->lcore_id, "r",
+			     &f_min);
+	FOPEN_OR_ERR_GOTO(f_max, out);
 
-	f_max = fopen(fullpath_max, "r");
-	if (f_max == NULL)
-		fclose(f_min);
+	/* read base ratios */
+	ret = read_core_sysfs_u32(f_max, &sys_max_freq);
+	FOPS_OR_ERR_GOTO(ret, out);
 
-	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;
-
-	p_max = strchr(buf_max, '\n');
-	if (p_max != NULL)
-		*p_max = 0;
-
-	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);
+	FOPS_OR_ERR_GOTO(ret, out);
 
 	if (sys_max_freq < sys_min_freq)
 		goto out;
@@ -576,27 +415,14 @@ 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,
-			pi->lcore_id);
-	f_cur = fopen(fullpath_cur, "r");
-	FOPEN_OR_ERR_RET(f_cur, ret);
+	open_core_sysfs_file(POWER_SYSFILE_CUR_FREQ, pi->lcore_id, "r", &f_cur);
+	FOPEN_OR_ERR_GOTO(f_cur, fail);
 
-	/* 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);
-
-	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);
+	FOPS_OR_ERR_GOTO(ret, fail);
 
 	/* convert the frequency to nearest 100000 value
 	 * Ex: if sys_cur_freq=1396789 then freq_conv=1400000
@@ -615,10 +441,10 @@ 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;
 }
 
-- 
2.25.1

Re: [dpdk-dev] [21.08 PATCH v4 2/2] power: refactor pstate and acpi code

[Richael Zhuang]

> -----Original Message-----
> From: Anatoly Burakov <anatoly.burakov@intel.com>
> Sent: Friday, April 23, 2021 7:03 PM
> To: dev@dpdk.org
> Cc: stephen@networkplumber.org; Richael Zhuang
> <Richael.Zhuang@arm.com>; reshma.pattan@intel.com;
> david.hunt@intel.com
> Subject: [21.08 PATCH v4 2/2] power: refactor pstate and acpi code
> 
> 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>
> ---
>  lib/power/meson.build            |   7 +
>  lib/power/power_acpi_cpufreq.c   | 178 +++--------------
>  lib/power/power_common.c         | 133 +++++++++++++
>  lib/power/power_common.h         |  46 +++++
>  lib/power/power_pstate_cpufreq.c | 332 ++++++++-----------------------
>  5 files changed, 293 insertions(+), 403 deletions(-)
> 
> diff --git a/lib/power/meson.build b/lib/power/meson.build index
> a2cc9fe2ef..85324d48d2 100644
> --- a/lib/power/meson.build
> +++ b/lib/power/meson.build
> @@ -5,6 +5,13 @@ if not is_linux
>      build = false
>      reason = 'only supported on Linux'
>  endif
> +
> +# we do some snprintf magic so silence format-nonliteral
> +flag_nonliteral = '-Wno-format-nonliteral'
> +if cc.has_argument(flag_nonliteral)
> +	cflags += flag_nonliteral
> +endif
> +
>  sources = files(
>          'guest_channel.c',
>          'power_acpi_cpufreq.c',
> diff --git a/lib/power/power_acpi_cpufreq.c
> b/lib/power/power_acpi_cpufreq.c index 1b8c69cc8b..97f1d302c9 100644
> --- a/lib/power/power_acpi_cpufreq.c
> +++ b/lib/power/power_acpi_cpufreq.c
> @@ -19,41 +19,10 @@
>  #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_frequen
> cies"
>  #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 ret;
> +	return power_set_governor(pi->lcore_id,
> POWER_GOVERNOR_USERSPACE,
> +			pi->governor_ori, sizeof(pi->governor_ori)); }
> +
> +/**
> + * 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 +129,14 @@ 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);
> +	open_core_sysfs_file(POWER_SYSFILE_AVAIL_FREQ, pi->lcore_id, "r",
> +			&f);
> +	FOPEN_OR_ERR_GOTO(f, out);
> 
> -	s = fgets(buf, sizeof(buf), f);
> -	FOPS_OR_NULL_GOTO(s, 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));
> +	FOPS_OR_ERR_GOTO(ret, out);
> 
>  	/* Split string into at most RTE_MAX_LCORE_FREQS frequencies */
>  	count = rte_strsplit(buf, sizeof(buf), freqs, @@ -250,7 +176,8 @@
> 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 +189,16 @@ 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(POWER_SYSFILE_SETSPEED, pi->lcore_id, "r",
> +			&f);
Hi Anatoly,
I tried to verify your patch on my arm platform,  and I found several bugs.

Here it should be "rw+", for it will write freq to POWER_SYSFILE_SETSPEED later.

Best Regards,
Richael
> +	FOPEN_OR_ERR_GOTO(f, err);
> 
> -	s = fgets(buf, sizeof(buf), f);
> -	FOPS_OR_NULL_GOTO(s, out);
> +	ret = read_core_sysfs_s(f, buf, sizeof(buf));
> +	FOPS_OR_ERR_GOTO(ret, err);
> 
>  	freq = strtoul(buf, NULL, POWER_CONVERT_TO_DECIMAL);
>  	for (i = 0; i < pi->nb_freqs; i++) {
> @@ -284,8 +209,9 @@ power_init_for_setting_freq(struct acpi_power_info
> *pi)
>  		}
>  	}
> 
> -out:
> -	fclose(f);
> +err:
> +	if (f != NULL)
> +		fclose(f);
> 
>  	return -1;
>  }
> @@ -369,54 +295,6 @@ power_acpi_cpufreq_init(unsigned int lcore_id)
>  	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)  { diff --git
> a/lib/power/power_common.c b/lib/power/power_common.c index
> 67e3318ec7..f06e9e5fa9 100644
> --- a/lib/power/power_common.c
> +++ b/lib/power/power_common.c
> @@ -3,13 +3,20 @@
>   */
> 
>  #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) @@ -58,3 +65,129
> @@ cpufreq_check_scaling_driver(const char *driver_name)
>  	 */
>  	return 1;
>  }
> +
> +int
> +open_core_sysfs_file(const char *template, unsigned int core, const char
> *mode,
> +		FILE **f)
> +{
> +	char fullpath[PATH_MAX];
> +	FILE *tmpf;
> +
> +	/* silenced -Wformat-nonliteral here */
> +	snprintf(fullpath, sizeof(fullpath), template, core);
> +	tmpf = fopen(fullpath, mode);
> +	if (tmpf == NULL)
> +		return -1;
> +	*f = tmpf;

When the file that open_core_sysfs_file() opens doesn't exist, there's segmentation fault.
Moving *f=tmpf above runs OK.

> +
> +	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)

ret >=0 if success, EOF means failure.

> +		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(POWER_SYSFILE_GOVERNOR, lcore_id, "rw+",
> &f_governor);
> +	FOPEN_OR_ERR_GOTO(f_governor, out);
> +
> +	ret = read_core_sysfs_s(f_governor, buf, sizeof(buf));
> +	FOPS_OR_ERR_GOTO(ret, 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);
> +	FOPS_OR_ERR_GOTO(ret, 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;
> +}
> diff --git a/lib/power/power_common.h b/lib/power/power_common.h
> index fab3ca995a..729ae8cbf4 100644
> --- a/lib/power/power_common.h
> +++ b/lib/power/power_common.h
> @@ -5,9 +5,55 @@
>  #ifndef _POWER_COMMON_H_
>  #define _POWER_COMMON_H_
> 
> +#include <inttypes.h>
> +
>  #define RTE_POWER_INVALID_FREQ_INDEX (~0)
> 
> +
> +#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 FOPEN_OR_ERR_GOTO(f, label) do { \
> +		if ((f) == NULL) { \
> +			RTE_LOG(ERR, POWER, "File not opened\n"); \
> +			goto label; \
> +		} \
> +} 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)
> +
>  /* 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(const char *template, unsigned int core,
> +			 const char *mode, FILE **f);
> +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_ */
> diff --git a/lib/power/power_pstate_cpufreq.c
> b/lib/power/power_pstate_cpufreq.c
> index 2cfc54acf3..2a365988a9 100644
> --- a/lib/power/power_pstate_cpufreq.c
> +++ b/lib/power/power_pstate_cpufreq.c
> @@ -21,46 +21,13 @@
>  #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 +121,58 @@ 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);
> -
> -		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;
> -	}
> -
> -	snprintf(fullpath_min, sizeof(fullpath_min),
> POWER_SYSFILE_MIN_FREQ,
> -			pi->lcore_id);
> -	f_min = fopen(fullpath_min, "rw+");
> -	FOPEN_OR_ERR_RET(f_min, -1);
> -
> -	snprintf(fullpath_max, sizeof(fullpath_max),
> 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;
> -
> -	snprintf(fullpath_base, sizeof(fullpath_base),
> POWER_SYSFILE_BASE_FREQ,
> -			pi->lcore_id);
> -
> -	f_base = fopen(fullpath_base, "r");
> -	if (f_base == NULL) {
> -		/* No sysfs base_frequency, that's OK, continue without */
> -		base_ratio = 0;
> +	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;
> +
> +	/* open all files we expect to have open */
> +	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi-
> >lcore_id, "r",
> +			&f_base_max);
> +	FOPEN_OR_ERR_GOTO(f_base_max, err);
> +
> +	open_core_sysfs_file(POWER_SYSFILE_MIN_FREQ, pi->lcore_id,
> "rw+",
> +			&f_min);
> +	FOPEN_OR_ERR_GOTO(f_min, err);
> +
> +	open_core_sysfs_file(POWER_SYSFILE_MAX_FREQ, pi->lcore_id,
> "rw+",
> +			&f_max);
> +	FOPEN_OR_ERR_GOTO(f_max, err);
> +
> +	open_core_sysfs_file(POWER_SYSFILE_BASE_FREQ, pi->lcore_id, "r",
> +			&f_base);
> +	/* base ratio file may not exist in some kernels, so no error check */
> +
> +	/* read base max ratio */
> +	ret = read_core_sysfs_u32(f_base_max, &base_max_ratio);
> +	FOPS_OR_ERR_GOTO(ret, err);
> +
> +	/* base ratio may not exist */
> +	if (f_base != NULL) {
> +		ret = read_core_sysfs_u32(f_base, &base_ratio);
> +		FOPS_OR_ERR_GOTO(ret, 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 +198,20 @@ 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 +316,8 @@ 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 +327,7 @@ power_set_governor_performance(struct
> pstate_power_info *pi)  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 +337,26 @@ power_set_governor_original(struct
> pstate_power_info *pi)  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,
> -			pi->lcore_id);
> +	/* open all files */
> +	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi-
> >lcore_id, "r",
> +			&f_max);
> +	FOPEN_OR_ERR_GOTO(f_max, out);
> 
> -	f_min = fopen(fullpath_min, "r");
> -	FOPEN_OR_ERR_RET(f_min, ret);
> +	open_core_sysfs_file(POWER_SYSFILE_BASE_MIN_FREQ, pi->lcore_id,
> "r",
> +			     &f_min);
> +	FOPEN_OR_ERR_GOTO(f_max, out);
> 
> -	f_max = fopen(fullpath_max, "r");
> -	if (f_max == NULL)
> -		fclose(f_min);
> +	/* read base ratios */
> +	ret = read_core_sysfs_u32(f_max, &sys_max_freq);
> +	FOPS_OR_ERR_GOTO(ret, out);
> 
> -	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;
> -
> -	p_max = strchr(buf_max, '\n');
> -	if (p_max != NULL)
> -		*p_max = 0;
> -
> -	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);
> +	FOPS_OR_ERR_GOTO(ret, out);
> 
>  	if (sys_max_freq < sys_min_freq)
>  		goto out;
> @@ -576,27 +415,14 @@ 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,
> -			pi->lcore_id);
> -	f_cur = fopen(fullpath_cur, "r");
> -	FOPEN_OR_ERR_RET(f_cur, ret);
> +	open_core_sysfs_file(POWER_SYSFILE_CUR_FREQ, pi->lcore_id, "r",
> &f_cur);
> +	FOPEN_OR_ERR_GOTO(f_cur, fail);
> 
> -	/* 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);
> -
> -	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);
> +	FOPS_OR_ERR_GOTO(ret, fail);
> 
>  	/* convert the frequency to nearest 100000 value
>  	 * Ex: if sys_cur_freq=1396789 then freq_conv=1400000 @@ -615,10
> +441,10 @@ 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;
>  }
> 
> --
> 2.25.1

Re: [dpdk-dev] [21.08 PATCH v4 2/2] power: refactor pstate and acpi code

[Burakov, Anatoly]

On 07-May-21 3:13 AM, Richael Zhuang wrote:
>> @@ -262,18 +189,16 @@ 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(POWER_SYSFILE_SETSPEED, pi->lcore_id, "r",
>> +			&f);
> Hi Anatoly,
> I tried to verify your patch on my arm platform,  and I found several bugs.
> 
> Here it should be "rw+", for it will write freq to POWER_SYSFILE_SETSPEED later.
> 
> Best Regards,
> Richael

<snip>

>>   	return 1;
>>   }
>> +
>> +int
>> +open_core_sysfs_file(const char *template, unsigned int core, const char
>> *mode,
>> +		FILE **f)
>> +{
>> +	char fullpath[PATH_MAX];
>> +	FILE *tmpf;
>> +
>> +	/* silenced -Wformat-nonliteral here */
>> +	snprintf(fullpath, sizeof(fullpath), template, core);
>> +	tmpf = fopen(fullpath, mode);
>> +	if (tmpf == NULL)
>> +		return -1;
>> +	*f = tmpf;
> 
> When the file that open_core_sysfs_file() opens doesn't exist, there's segmentation fault.
> Moving *f=tmpf above runs OK.
> 
>> +
>> +	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;
>> +

<snip>

>> +	/* 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)
> 
> ret >=0 if success, EOF means failure.
> 

Hi Richael,

Thank you very much for testing! I'll address these issues in the next 
revision, and double-check everything else.

-- 
Thanks,
Anatoly

Re: [dpdk-dev] [21.08 PATCH v4 1/2] power: don't use rte prefix in internal code

[David Hunt]

Hi Anatoly

On 23/4/2021 12:03 PM, Anatoly Burakov wrote:
> Currently, ACPI code uses rte_power_info as the struct name, which
> gives the appearance that this is an externally visible API. Fix to
> use internal namespace.
>
> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> ---
>   lib/power/power_acpi_cpufreq.c | 34 +++++++++++++++++-----------------
>   1 file changed, 17 insertions(+), 17 deletions(-)
>

Looks good. This brings the acpi driver code in line with the pstate 
driver code, which already
has it's struct called ptate_power_info.

Acked-by: David Hunt <david.hunt@intel.com>

[dpdk-dev] [PATCH v2 1/2] power: don't use rte prefix in internal code

[David Hunt]

From: Anatoly Burakov <anatoly.burakov@intel.com>

Currently, ACPI code uses rte_power_info as the struct name, which
gives the appearance that this is an externally visible API. Fix to
use internal namespace.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: David Hunt <david.hunt@intel.com>
---
 lib/power/power_acpi_cpufreq.c | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/lib/power/power_acpi_cpufreq.c b/lib/power/power_acpi_cpufreq.c
index d028a9947f..1b8c69cc8b 100644
--- a/lib/power/power_acpi_cpufreq.c
+++ b/lib/power/power_acpi_cpufreq.c
@@ -78,7 +78,7 @@ enum power_state {
 /**
  * Power info per lcore.
  */
-struct rte_power_info {
+struct acpi_power_info {
 	unsigned int lcore_id;                   /**< Logical core id */
 	uint32_t freqs[RTE_MAX_LCORE_FREQS]; /**< Frequency array */
 	uint32_t nb_freqs;                   /**< number of available freqs */
@@ -90,14 +90,14 @@ struct rte_power_info {
 	uint16_t turbo_enable;               /**< Turbo Boost enable/disable */
 } __rte_cache_aligned;
 
-static struct rte_power_info lcore_power_info[RTE_MAX_LCORE];
+static struct acpi_power_info lcore_power_info[RTE_MAX_LCORE];
 
 /**
  * It is to set specific freq for specific logical core, according to the index
  * of supported frequencies.
  */
 static int
-set_freq_internal(struct rte_power_info *pi, uint32_t idx)
+set_freq_internal(struct acpi_power_info *pi, uint32_t idx)
 {
 	if (idx >= RTE_MAX_LCORE_FREQS || idx >= pi->nb_freqs) {
 		RTE_LOG(ERR, POWER, "Invalid frequency index %u, which "
@@ -133,7 +133,7 @@ set_freq_internal(struct rte_power_info *pi, uint32_t idx)
  * governor will be saved for rolling back.
  */
 static int
-power_set_governor_userspace(struct rte_power_info *pi)
+power_set_governor_userspace(struct acpi_power_info *pi)
 {
 	FILE *f;
 	int ret = -1;
@@ -189,7 +189,7 @@ power_set_governor_userspace(struct rte_power_info *pi)
  * sys file.
  */
 static int
-power_get_available_freqs(struct rte_power_info *pi)
+power_get_available_freqs(struct acpi_power_info *pi)
 {
 	FILE *f;
 	int ret = -1, i, count;
@@ -259,7 +259,7 @@ power_get_available_freqs(struct rte_power_info *pi)
  * It is to fopen the sys file for the future setting the lcore frequency.
  */
 static int
-power_init_for_setting_freq(struct rte_power_info *pi)
+power_init_for_setting_freq(struct acpi_power_info *pi)
 {
 	FILE *f;
 	char fullpath[PATH_MAX];
@@ -299,7 +299,7 @@ power_acpi_cpufreq_check_supported(void)
 int
 power_acpi_cpufreq_init(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 	uint32_t exp_state;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
@@ -374,7 +374,7 @@ power_acpi_cpufreq_init(unsigned int lcore_id)
  * needed by writing the sys file.
  */
 static int
-power_set_governor_original(struct rte_power_info *pi)
+power_set_governor_original(struct acpi_power_info *pi)
 {
 	FILE *f;
 	int ret = -1;
@@ -420,7 +420,7 @@ power_set_governor_original(struct rte_power_info *pi)
 int
 power_acpi_cpufreq_exit(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 	uint32_t exp_state;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
@@ -475,7 +475,7 @@ power_acpi_cpufreq_exit(unsigned int lcore_id)
 uint32_t
 power_acpi_cpufreq_freqs(unsigned int lcore_id, uint32_t *freqs, uint32_t num)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -522,7 +522,7 @@ power_acpi_cpufreq_set_freq(unsigned int lcore_id, uint32_t index)
 int
 power_acpi_cpufreq_freq_down(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -540,7 +540,7 @@ power_acpi_cpufreq_freq_down(unsigned int lcore_id)
 int
 power_acpi_cpufreq_freq_up(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -581,7 +581,7 @@ power_acpi_cpufreq_freq_max(unsigned int lcore_id)
 int
 power_acpi_cpufreq_freq_min(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -598,7 +598,7 @@ power_acpi_cpufreq_freq_min(unsigned int lcore_id)
 int
 power_acpi_turbo_status(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -614,7 +614,7 @@ power_acpi_turbo_status(unsigned int lcore_id)
 int
 power_acpi_enable_turbo(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -647,7 +647,7 @@ power_acpi_enable_turbo(unsigned int lcore_id)
 int
 power_acpi_disable_turbo(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -674,7 +674,7 @@ power_acpi_disable_turbo(unsigned int lcore_id)
 int power_acpi_get_capabilities(unsigned int lcore_id,
 		struct rte_power_core_capabilities *caps)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
-- 
2.17.1

[dpdk-dev] [PATCH v2 2/2] power: refactor pstate and acpi code

[David Hunt]

From: Anatoly Burakov <anatoly.burakov@intel.com>

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>

---
changes in v2
* fixed bugs raised by Richael Zhuang in review - open file rw+, etc.
* removed FOPS* and FOPEN* macros, which contained control statements.
* fixed some checkpatch warnings.
---
 lib/power/meson.build            |   7 +
 lib/power/power_acpi_cpufreq.c   | 192 ++++------------
 lib/power/power_common.c         | 146 ++++++++++++
 lib/power/power_common.h         |  17 ++
 lib/power/power_pstate_cpufreq.c | 374 ++++++++++---------------------
 5 files changed, 335 insertions(+), 401 deletions(-)

diff --git a/lib/power/meson.build b/lib/power/meson.build
index c1097d32f1..74c5f3a294 100644
--- a/lib/power/meson.build
+++ b/lib/power/meson.build
@@ -5,6 +5,13 @@ if not is_linux
     build = false
     reason = 'only supported on Linux'
 endif
+
+# we do some snprintf magic so silence format-nonliteral
+flag_nonliteral = '-Wno-format-nonliteral'
+if cc.has_argument(flag_nonliteral)
+	cflags += flag_nonliteral
+endif
+
 sources = files(
         'guest_channel.c',
         'power_acpi_cpufreq.c',
diff --git a/lib/power/power_acpi_cpufreq.c b/lib/power/power_acpi_cpufreq.c
index 1b8c69cc8b..9ca8d8a8f2 100644
--- a/lib/power/power_acpi_cpufreq.c
+++ b/lib/power/power_acpi_cpufreq.c
@@ -19,41 +19,10 @@
 #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 +129,22 @@ 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(POWER_SYSFILE_AVAIL_FREQ, pi->lcore_id, "r",
+			&f);
+	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 +184,8 @@ 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 +197,24 @@ 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(POWER_SYSFILE_SETSPEED, pi->lcore_id, "rw+",
+			&f);
+	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 +225,9 @@ power_init_for_setting_freq(struct acpi_power_info *pi)
 		}
 	}
 
-out:
-	fclose(f);
+err:
+	if (f != NULL)
+		fclose(f);
 
 	return -1;
 }
@@ -369,54 +311,6 @@ power_acpi_cpufreq_init(unsigned int lcore_id)
 	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)
 {
diff --git a/lib/power/power_common.c b/lib/power/power_common.c
index 67e3318ec7..0295b89f10 100644
--- a/lib/power/power_common.c
+++ b/lib/power/power_common.c
@@ -3,13 +3,20 @@
  */
 
 #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)
@@ -58,3 +65,142 @@ cpufreq_check_scaling_driver(const char *driver_name)
 	 */
 	return 1;
 }
+
+int
+open_core_sysfs_file(const char *template, unsigned int core, const char *mode,
+		FILE **f)
+{
+	char fullpath[PATH_MAX];
+	FILE *tmpf;
+
+	/* silenced -Wformat-nonliteral here */
+	snprintf(fullpath, sizeof(fullpath), template, core);
+	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(POWER_SYSFILE_GOVERNOR, lcore_id, "rw+",
+			&f_governor);
+	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;
+}
diff --git a/lib/power/power_common.h b/lib/power/power_common.h
index fab3ca995a..ef9f5fa855 100644
--- a/lib/power/power_common.h
+++ b/lib/power/power_common.h
@@ -5,9 +5,26 @@
 #ifndef _POWER_COMMON_H_
 #define _POWER_COMMON_H_
 
+#include <inttypes.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(const char *template, unsigned int core,
+			 const char *mode, FILE **f);
+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_ */
diff --git a/lib/power/power_pstate_cpufreq.c b/lib/power/power_pstate_cpufreq.c
index 2cfc54acf3..ed10bd193b 100644
--- a/lib/power/power_pstate_cpufreq.c
+++ b/lib/power/power_pstate_cpufreq.c
@@ -21,46 +21,13 @@
 #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);
-
-		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;
+	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;
+
+	/* open all files we expect to have open */
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi->lcore_id, "r",
+			&f_base_max);
+	if (f_base_max == NULL) {
+		RTE_LOG(ERR, POWER, "failed to open %s\n",
+				POWER_SYSFILE_BASE_MAX_FREQ);
+		goto err;
+	}
+
+	open_core_sysfs_file(POWER_SYSFILE_MIN_FREQ, pi->lcore_id, "rw+",
+			&f_min);
+	if (f_min == NULL) {
+		RTE_LOG(ERR, POWER, "failed to open %s\n",
+				POWER_SYSFILE_MIN_FREQ);
+		goto err;
+	}
+
+	open_core_sysfs_file(POWER_SYSFILE_MAX_FREQ, pi->lcore_id, "rw+",
+			&f_max);
+	if (f_max == NULL) {
+		RTE_LOG(ERR, POWER, "failed to open %s\n",
+				POWER_SYSFILE_MAX_FREQ);
+		goto err;
+	}
+
+	open_core_sysfs_file(POWER_SYSFILE_BASE_FREQ, pi->lcore_id, "r",
+			&f_base);
+	/* base ratio file may not exist in some kernels, so no error check */
+
+	/* 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 {
+		base_ratio = 0;
 	}
 
-	snprintf(fullpath_min, sizeof(fullpath_min), POWER_SYSFILE_MIN_FREQ,
-			pi->lcore_id);
-	f_min = fopen(fullpath_min, "rw+");
-	FOPEN_OR_ERR_RET(f_min, -1);
+	/* 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 */
 
-	snprintf(fullpath_max, sizeof(fullpath_max), 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);
+	/* 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;
 
-	snprintf(fullpath_base, sizeof(fullpath_base), POWER_SYSFILE_BASE_FREQ,
-			pi->lcore_id);
-
-	f_base = fopen(fullpath_base, "r");
-	if (f_base == NULL) {
-		/* No sysfs base_frequency, that's OK, continue without */
-		base_ratio = 0;
-	} 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;
-	}
-
-	/* Add MSR read to detect turbo status */
-
-	if (power_rdmsr(PLATFORM_INFO, &max_non_turbo, pi->lcore_id) < 0) {
-		ret_val = -1;
-		goto out;
-	}
-
 	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 @@ power_set_governor_performance(struct pstate_power_info *pi)
 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 @@ power_set_governor_original(struct pstate_power_info *pi)
 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,
-			pi->lcore_id);
-
-	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);
-
+	/* open all files */
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi->lcore_id, "r",
+			&f_max);
+	if (f_max == NULL) {
+		RTE_LOG(ERR, POWER, "failed to open %s\n",
+				POWER_SYSFILE_BASE_MAX_FREQ);
+		goto 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(POWER_SYSFILE_BASE_MIN_FREQ, pi->lcore_id, "r",
+			     &f_min);
+	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 +451,22 @@ 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,
-			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);
+	open_core_sysfs_file(POWER_SYSFILE_CUR_FREQ, pi->lcore_id, "r", &f_cur);
+	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 +485,10 @@ 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;
 }
 
-- 
2.17.1

[dpdk-dev] [PATCH v5 1/2] power: don't use rte prefix in internal code

[David Hunt]

From: Anatoly Burakov <anatoly.burakov@intel.com>

Currently, ACPI code uses rte_power_info as the struct name, which
gives the appearance that this is an externally visible API. Fix to
use internal namespace.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: David Hunt <david.hunt@intel.com>
---
 lib/power/power_acpi_cpufreq.c | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/lib/power/power_acpi_cpufreq.c b/lib/power/power_acpi_cpufreq.c
index d028a9947f..1b8c69cc8b 100644
--- a/lib/power/power_acpi_cpufreq.c
+++ b/lib/power/power_acpi_cpufreq.c
@@ -78,7 +78,7 @@ enum power_state {
 /**
  * Power info per lcore.
  */
-struct rte_power_info {
+struct acpi_power_info {
 	unsigned int lcore_id;                   /**< Logical core id */
 	uint32_t freqs[RTE_MAX_LCORE_FREQS]; /**< Frequency array */
 	uint32_t nb_freqs;                   /**< number of available freqs */
@@ -90,14 +90,14 @@ struct rte_power_info {
 	uint16_t turbo_enable;               /**< Turbo Boost enable/disable */
 } __rte_cache_aligned;
 
-static struct rte_power_info lcore_power_info[RTE_MAX_LCORE];
+static struct acpi_power_info lcore_power_info[RTE_MAX_LCORE];
 
 /**
  * It is to set specific freq for specific logical core, according to the index
  * of supported frequencies.
  */
 static int
-set_freq_internal(struct rte_power_info *pi, uint32_t idx)
+set_freq_internal(struct acpi_power_info *pi, uint32_t idx)
 {
 	if (idx >= RTE_MAX_LCORE_FREQS || idx >= pi->nb_freqs) {
 		RTE_LOG(ERR, POWER, "Invalid frequency index %u, which "
@@ -133,7 +133,7 @@ set_freq_internal(struct rte_power_info *pi, uint32_t idx)
  * governor will be saved for rolling back.
  */
 static int
-power_set_governor_userspace(struct rte_power_info *pi)
+power_set_governor_userspace(struct acpi_power_info *pi)
 {
 	FILE *f;
 	int ret = -1;
@@ -189,7 +189,7 @@ power_set_governor_userspace(struct rte_power_info *pi)
  * sys file.
  */
 static int
-power_get_available_freqs(struct rte_power_info *pi)
+power_get_available_freqs(struct acpi_power_info *pi)
 {
 	FILE *f;
 	int ret = -1, i, count;
@@ -259,7 +259,7 @@ power_get_available_freqs(struct rte_power_info *pi)
  * It is to fopen the sys file for the future setting the lcore frequency.
  */
 static int
-power_init_for_setting_freq(struct rte_power_info *pi)
+power_init_for_setting_freq(struct acpi_power_info *pi)
 {
 	FILE *f;
 	char fullpath[PATH_MAX];
@@ -299,7 +299,7 @@ power_acpi_cpufreq_check_supported(void)
 int
 power_acpi_cpufreq_init(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 	uint32_t exp_state;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
@@ -374,7 +374,7 @@ power_acpi_cpufreq_init(unsigned int lcore_id)
  * needed by writing the sys file.
  */
 static int
-power_set_governor_original(struct rte_power_info *pi)
+power_set_governor_original(struct acpi_power_info *pi)
 {
 	FILE *f;
 	int ret = -1;
@@ -420,7 +420,7 @@ power_set_governor_original(struct rte_power_info *pi)
 int
 power_acpi_cpufreq_exit(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 	uint32_t exp_state;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
@@ -475,7 +475,7 @@ power_acpi_cpufreq_exit(unsigned int lcore_id)
 uint32_t
 power_acpi_cpufreq_freqs(unsigned int lcore_id, uint32_t *freqs, uint32_t num)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -522,7 +522,7 @@ power_acpi_cpufreq_set_freq(unsigned int lcore_id, uint32_t index)
 int
 power_acpi_cpufreq_freq_down(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -540,7 +540,7 @@ power_acpi_cpufreq_freq_down(unsigned int lcore_id)
 int
 power_acpi_cpufreq_freq_up(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -581,7 +581,7 @@ power_acpi_cpufreq_freq_max(unsigned int lcore_id)
 int
 power_acpi_cpufreq_freq_min(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -598,7 +598,7 @@ power_acpi_cpufreq_freq_min(unsigned int lcore_id)
 int
 power_acpi_turbo_status(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -614,7 +614,7 @@ power_acpi_turbo_status(unsigned int lcore_id)
 int
 power_acpi_enable_turbo(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -647,7 +647,7 @@ power_acpi_enable_turbo(unsigned int lcore_id)
 int
 power_acpi_disable_turbo(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -674,7 +674,7 @@ power_acpi_disable_turbo(unsigned int lcore_id)
 int power_acpi_get_capabilities(unsigned int lcore_id,
 		struct rte_power_core_capabilities *caps)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
-- 
2.17.1

[dpdk-dev] [PATCH v5 2/2] power: refactor pstate and acpi code

[David Hunt]

From: Anatoly Burakov <anatoly.burakov@intel.com>

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>

---
changes in v2
* fixed bugs raised by Richael Zhuang in review - open file rw+, etc.
* removed FOPS* and FOPEN* macros, which contained control statements.
* fixed some checkpatch warnings.
---
 lib/power/meson.build            |   7 +
 lib/power/power_acpi_cpufreq.c   | 192 ++++------------
 lib/power/power_common.c         | 146 ++++++++++++
 lib/power/power_common.h         |  17 ++
 lib/power/power_pstate_cpufreq.c | 374 ++++++++++---------------------
 5 files changed, 335 insertions(+), 401 deletions(-)

diff --git a/lib/power/meson.build b/lib/power/meson.build
index c1097d32f1..74c5f3a294 100644
--- a/lib/power/meson.build
+++ b/lib/power/meson.build
@@ -5,6 +5,13 @@ if not is_linux
     build = false
     reason = 'only supported on Linux'
 endif
+
+# we do some snprintf magic so silence format-nonliteral
+flag_nonliteral = '-Wno-format-nonliteral'
+if cc.has_argument(flag_nonliteral)
+	cflags += flag_nonliteral
+endif
+
 sources = files(
         'guest_channel.c',
         'power_acpi_cpufreq.c',
diff --git a/lib/power/power_acpi_cpufreq.c b/lib/power/power_acpi_cpufreq.c
index 1b8c69cc8b..9ca8d8a8f2 100644
--- a/lib/power/power_acpi_cpufreq.c
+++ b/lib/power/power_acpi_cpufreq.c
@@ -19,41 +19,10 @@
 #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 +129,22 @@ 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(POWER_SYSFILE_AVAIL_FREQ, pi->lcore_id, "r",
+			&f);
+	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 +184,8 @@ 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 +197,24 @@ 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(POWER_SYSFILE_SETSPEED, pi->lcore_id, "rw+",
+			&f);
+	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 +225,9 @@ power_init_for_setting_freq(struct acpi_power_info *pi)
 		}
 	}
 
-out:
-	fclose(f);
+err:
+	if (f != NULL)
+		fclose(f);
 
 	return -1;
 }
@@ -369,54 +311,6 @@ power_acpi_cpufreq_init(unsigned int lcore_id)
 	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)
 {
diff --git a/lib/power/power_common.c b/lib/power/power_common.c
index 67e3318ec7..0295b89f10 100644
--- a/lib/power/power_common.c
+++ b/lib/power/power_common.c
@@ -3,13 +3,20 @@
  */
 
 #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)
@@ -58,3 +65,142 @@ cpufreq_check_scaling_driver(const char *driver_name)
 	 */
 	return 1;
 }
+
+int
+open_core_sysfs_file(const char *template, unsigned int core, const char *mode,
+		FILE **f)
+{
+	char fullpath[PATH_MAX];
+	FILE *tmpf;
+
+	/* silenced -Wformat-nonliteral here */
+	snprintf(fullpath, sizeof(fullpath), template, core);
+	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(POWER_SYSFILE_GOVERNOR, lcore_id, "rw+",
+			&f_governor);
+	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;
+}
diff --git a/lib/power/power_common.h b/lib/power/power_common.h
index fab3ca995a..ef9f5fa855 100644
--- a/lib/power/power_common.h
+++ b/lib/power/power_common.h
@@ -5,9 +5,26 @@
 #ifndef _POWER_COMMON_H_
 #define _POWER_COMMON_H_
 
+#include <inttypes.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(const char *template, unsigned int core,
+			 const char *mode, FILE **f);
+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_ */
diff --git a/lib/power/power_pstate_cpufreq.c b/lib/power/power_pstate_cpufreq.c
index 2cfc54acf3..ed10bd193b 100644
--- a/lib/power/power_pstate_cpufreq.c
+++ b/lib/power/power_pstate_cpufreq.c
@@ -21,46 +21,13 @@
 #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);
-
-		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;
+	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;
+
+	/* open all files we expect to have open */
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi->lcore_id, "r",
+			&f_base_max);
+	if (f_base_max == NULL) {
+		RTE_LOG(ERR, POWER, "failed to open %s\n",
+				POWER_SYSFILE_BASE_MAX_FREQ);
+		goto err;
+	}
+
+	open_core_sysfs_file(POWER_SYSFILE_MIN_FREQ, pi->lcore_id, "rw+",
+			&f_min);
+	if (f_min == NULL) {
+		RTE_LOG(ERR, POWER, "failed to open %s\n",
+				POWER_SYSFILE_MIN_FREQ);
+		goto err;
+	}
+
+	open_core_sysfs_file(POWER_SYSFILE_MAX_FREQ, pi->lcore_id, "rw+",
+			&f_max);
+	if (f_max == NULL) {
+		RTE_LOG(ERR, POWER, "failed to open %s\n",
+				POWER_SYSFILE_MAX_FREQ);
+		goto err;
+	}
+
+	open_core_sysfs_file(POWER_SYSFILE_BASE_FREQ, pi->lcore_id, "r",
+			&f_base);
+	/* base ratio file may not exist in some kernels, so no error check */
+
+	/* 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 {
+		base_ratio = 0;
 	}
 
-	snprintf(fullpath_min, sizeof(fullpath_min), POWER_SYSFILE_MIN_FREQ,
-			pi->lcore_id);
-	f_min = fopen(fullpath_min, "rw+");
-	FOPEN_OR_ERR_RET(f_min, -1);
+	/* 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 */
 
-	snprintf(fullpath_max, sizeof(fullpath_max), 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);
+	/* 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;
 
-	snprintf(fullpath_base, sizeof(fullpath_base), POWER_SYSFILE_BASE_FREQ,
-			pi->lcore_id);
-
-	f_base = fopen(fullpath_base, "r");
-	if (f_base == NULL) {
-		/* No sysfs base_frequency, that's OK, continue without */
-		base_ratio = 0;
-	} 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;
-	}
-
-	/* Add MSR read to detect turbo status */
-
-	if (power_rdmsr(PLATFORM_INFO, &max_non_turbo, pi->lcore_id) < 0) {
-		ret_val = -1;
-		goto out;
-	}
-
 	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 @@ power_set_governor_performance(struct pstate_power_info *pi)
 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 @@ power_set_governor_original(struct pstate_power_info *pi)
 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,
-			pi->lcore_id);
-
-	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);
-
+	/* open all files */
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi->lcore_id, "r",
+			&f_max);
+	if (f_max == NULL) {
+		RTE_LOG(ERR, POWER, "failed to open %s\n",
+				POWER_SYSFILE_BASE_MAX_FREQ);
+		goto 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(POWER_SYSFILE_BASE_MIN_FREQ, pi->lcore_id, "r",
+			     &f_min);
+	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 +451,22 @@ 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,
-			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);
+	open_core_sysfs_file(POWER_SYSFILE_CUR_FREQ, pi->lcore_id, "r", &f_cur);
+	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 +485,10 @@ 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;
 }
 
-- 
2.17.1

Re: [dpdk-dev] [PATCH v2 1/2] power: don't use rte prefix in internal code

[David Hunt]

On 22/6/2021 1:43 PM, David Hunt wrote:
> From: Anatoly Burakov <anatoly.burakov@intel.com>
>
> Currently, ACPI code uses rte_power_info as the struct name, which
> gives the appearance that this is an externally visible API. Fix to
> use internal namespace.
>
> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> Acked-by: David Hunt <david.hunt@intel.com>
> ---
>   lib/power/power_acpi_cpufreq.c | 34 +++++++++++++++++-----------------
>   1 file changed, 17 insertions(+), 17 deletions(-)
>

Please ignore, should have been sent as v5.

Re: [dpdk-dev] [PATCH v2 2/2] power: refactor pstate and acpi code

[David Hunt]

On 22/6/2021 1:43 PM, David Hunt wrote:
> From: Anatoly Burakov <anatoly.burakov@intel.com>
>
> 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>
>
> ---
> changes in v2
> * fixed bugs raised by Richael Zhuang in review - open file rw+, etc.
> * removed FOPS* and FOPEN* macros, which contained control statements.
> * fixed some checkpatch warnings.




Please ignore, should have been sent as v5.

Re: [dpdk-dev] [PATCH v5 2/2] power: refactor pstate and acpi code

[David Hunt]

Adding people to the CC list that were on v4 of this patch set, and 
Richael who raised some issues in v4.

On 22/6/2021 1:58 PM, David Hunt wrote:
> From: Anatoly Burakov <anatoly.burakov@intel.com>
>
> 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>
>
> ---
> changes in v2 (should read v5)
> * fixed bugs raised by Richael Zhuang in review - open file rw+, etc.
> * removed FOPS* and FOPEN* macros, which contained control statements.
> * fixed some checkpatch warnings.


So in the process of posting v5, I picked the email id from v4 in 
patchwork, used that in my --in-reply-to, and somehow it screwed up the 
threading as it looks like I'm responding to v3. So I'm sending this 
email to make sure all the people CC'd in v4 are included in this (v5).

Anatoly is busy at the moment, so I'm addressing the issues raised in 
v4, and additionally adressing the checkpatch issues where it does not 
like the macros with control statements, so removing those, as I don't 
like them either.

Regards,
Dave.

Re: [dpdk-dev] [PATCH v5 2/2] power: refactor pstate and acpi code

[Richael Zhuang]

Hi,
 There is a bug in lib/power/power_common.c:
+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;
Here, I mentioned in the V4 patch:  ret >=0 if success, EOF means failure.  It seems you forgot to fix this.
+
+	/* flush the output */
+	ret = fflush(f);
+	if (ret != 0)
+		return -1;
+
+	return 0;
+}

Best regards,
Richael
> -----Original Message-----
> From: David Hunt <david.hunt@intel.com>
> Sent: Tuesday, June 22, 2021 9:28 PM
> To: dev@dpdk.org
> Cc: anatoly.burakov@intel.com; stephen@networkplumber.org; Richael
> Zhuang <Richael.Zhuang@arm.com>; Reshma Pattan
> <reshma.pattan@intel.com>; nd <nd@arm.com>
> Subject: Re: [PATCH v5 2/2] power: refactor pstate and acpi code
> 
> Adding people to the CC list that were on v4 of this patch set, and Richael
> who raised some issues in v4.
> 
> On 22/6/2021 1:58 PM, David Hunt wrote:
> > From: Anatoly Burakov <anatoly.burakov@intel.com>
> >
> > 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>
> >
> > ---
> > changes in v2 (should read v5)
> > * fixed bugs raised by Richael Zhuang in review - open file rw+, etc.
> > * removed FOPS* and FOPEN* macros, which contained control statements.
> > * fixed some checkpatch warnings.
> 
> 
> So in the process of posting v5, I picked the email id from v4 in patchwork,
> used that in my --in-reply-to, and somehow it screwed up the threading as it
> looks like I'm responding to v3. So I'm sending this email to make sure all the
> people CC'd in v4 are included in this (v5).
> 
> Anatoly is busy at the moment, so I'm addressing the issues raised in v4, and
> additionally adressing the checkpatch issues where it does not like the
> macros with control statements, so removing those, as I don't like them
> either.
> 
> Regards,
> Dave.
> 
> 
> 

Re: [dpdk-dev] [PATCH v5 2/2] power: refactor pstate and acpi code

[David Hunt]

On 23/6/2021 9:54 AM, Richael Zhuang wrote:
> Hi,
>   There is a bug in lib/power/power_common.c:
> +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;
> Here, I mentioned in the V4 patch:  ret >=0 if success, EOF means failure.  It seems you forgot to fix this.


Ah, OK. Will fix in v6. Hopefully I'll reply to the correct email-id 
this time. :)


> +
> +	/* flush the output */
> +	ret = fflush(f);
> +	if (ret != 0)
> +		return -1;
> +
> +	return 0;
> +}
>
> Best regards,
> Richael
>> -----Original Message-----
>> From: David Hunt <david.hunt@intel.com>
>> Sent: Tuesday, June 22, 2021 9:28 PM
>> To: dev@dpdk.org
>> Cc: anatoly.burakov@intel.com; stephen@networkplumber.org; Richael
>> Zhuang <Richael.Zhuang@arm.com>; Reshma Pattan
>> <reshma.pattan@intel.com>; nd <nd@arm.com>
>> Subject: Re: [PATCH v5 2/2] power: refactor pstate and acpi code
>>
>> Adding people to the CC list that were on v4 of this patch set, and Richael
>> who raised some issues in v4.
>>
>> On 22/6/2021 1:58 PM, David Hunt wrote:
>>> From: Anatoly Burakov <anatoly.burakov@intel.com>
>>>
>>> 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>
>>>
>>> ---
>>> changes in v2 (should read v5)
>>> * fixed bugs raised by Richael Zhuang in review - open file rw+, etc.
>>> * removed FOPS* and FOPEN* macros, which contained control statements.
>>> * fixed some checkpatch warnings.
>>
>> So in the process of posting v5, I picked the email id from v4 in patchwork,
>> used that in my --in-reply-to, and somehow it screwed up the threading as it
>> looks like I'm responding to v3. So I'm sending this email to make sure all the
>> people CC'd in v4 are included in this (v5).
>>
>> Anatoly is busy at the moment, so I'm addressing the issues raised in v4, and
>> additionally adressing the checkpatch issues where it does not like the
>> macros with control statements, so removing those, as I don't like them
>> either.
>>
>> Regards,
>> Dave.
>>
>>
>>

[dpdk-dev] [PATCH v6 1/2] power: don't use rte prefix in internal code

[David Hunt]

From: Anatoly Burakov <anatoly.burakov@intel.com>

Currently, ACPI code uses rte_power_info as the struct name, which
gives the appearance that this is an externally visible API. Fix to
use internal namespace.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: David Hunt <david.hunt@intel.com>
---
 lib/power/power_acpi_cpufreq.c | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/lib/power/power_acpi_cpufreq.c b/lib/power/power_acpi_cpufreq.c
index d028a9947f..1b8c69cc8b 100644
--- a/lib/power/power_acpi_cpufreq.c
+++ b/lib/power/power_acpi_cpufreq.c
@@ -78,7 +78,7 @@ enum power_state {
 /**
  * Power info per lcore.
  */
-struct rte_power_info {
+struct acpi_power_info {
 	unsigned int lcore_id;                   /**< Logical core id */
 	uint32_t freqs[RTE_MAX_LCORE_FREQS]; /**< Frequency array */
 	uint32_t nb_freqs;                   /**< number of available freqs */
@@ -90,14 +90,14 @@ struct rte_power_info {
 	uint16_t turbo_enable;               /**< Turbo Boost enable/disable */
 } __rte_cache_aligned;
 
-static struct rte_power_info lcore_power_info[RTE_MAX_LCORE];
+static struct acpi_power_info lcore_power_info[RTE_MAX_LCORE];
 
 /**
  * It is to set specific freq for specific logical core, according to the index
  * of supported frequencies.
  */
 static int
-set_freq_internal(struct rte_power_info *pi, uint32_t idx)
+set_freq_internal(struct acpi_power_info *pi, uint32_t idx)
 {
 	if (idx >= RTE_MAX_LCORE_FREQS || idx >= pi->nb_freqs) {
 		RTE_LOG(ERR, POWER, "Invalid frequency index %u, which "
@@ -133,7 +133,7 @@ set_freq_internal(struct rte_power_info *pi, uint32_t idx)
  * governor will be saved for rolling back.
  */
 static int
-power_set_governor_userspace(struct rte_power_info *pi)
+power_set_governor_userspace(struct acpi_power_info *pi)
 {
 	FILE *f;
 	int ret = -1;
@@ -189,7 +189,7 @@ power_set_governor_userspace(struct rte_power_info *pi)
  * sys file.
  */
 static int
-power_get_available_freqs(struct rte_power_info *pi)
+power_get_available_freqs(struct acpi_power_info *pi)
 {
 	FILE *f;
 	int ret = -1, i, count;
@@ -259,7 +259,7 @@ power_get_available_freqs(struct rte_power_info *pi)
  * It is to fopen the sys file for the future setting the lcore frequency.
  */
 static int
-power_init_for_setting_freq(struct rte_power_info *pi)
+power_init_for_setting_freq(struct acpi_power_info *pi)
 {
 	FILE *f;
 	char fullpath[PATH_MAX];
@@ -299,7 +299,7 @@ power_acpi_cpufreq_check_supported(void)
 int
 power_acpi_cpufreq_init(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 	uint32_t exp_state;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
@@ -374,7 +374,7 @@ power_acpi_cpufreq_init(unsigned int lcore_id)
  * needed by writing the sys file.
  */
 static int
-power_set_governor_original(struct rte_power_info *pi)
+power_set_governor_original(struct acpi_power_info *pi)
 {
 	FILE *f;
 	int ret = -1;
@@ -420,7 +420,7 @@ power_set_governor_original(struct rte_power_info *pi)
 int
 power_acpi_cpufreq_exit(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 	uint32_t exp_state;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
@@ -475,7 +475,7 @@ power_acpi_cpufreq_exit(unsigned int lcore_id)
 uint32_t
 power_acpi_cpufreq_freqs(unsigned int lcore_id, uint32_t *freqs, uint32_t num)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -522,7 +522,7 @@ power_acpi_cpufreq_set_freq(unsigned int lcore_id, uint32_t index)
 int
 power_acpi_cpufreq_freq_down(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -540,7 +540,7 @@ power_acpi_cpufreq_freq_down(unsigned int lcore_id)
 int
 power_acpi_cpufreq_freq_up(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -581,7 +581,7 @@ power_acpi_cpufreq_freq_max(unsigned int lcore_id)
 int
 power_acpi_cpufreq_freq_min(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -598,7 +598,7 @@ power_acpi_cpufreq_freq_min(unsigned int lcore_id)
 int
 power_acpi_turbo_status(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -614,7 +614,7 @@ power_acpi_turbo_status(unsigned int lcore_id)
 int
 power_acpi_enable_turbo(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -647,7 +647,7 @@ power_acpi_enable_turbo(unsigned int lcore_id)
 int
 power_acpi_disable_turbo(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -674,7 +674,7 @@ power_acpi_disable_turbo(unsigned int lcore_id)
 int power_acpi_get_capabilities(unsigned int lcore_id,
 		struct rte_power_core_capabilities *caps)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
-- 
2.17.1

[dpdk-dev] [PATCH v6 2/2] power: refactor pstate and acpi code

[David Hunt]

From: Anatoly Burakov <anatoly.burakov@intel.com>

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>

---
changes in v5
* fixed bugs raised by Richael Zhuang in review - open file rw+, etc.
* removed FOPS* and FOPEN* macros, which contained control statements.
* fixed some checkpatch warnings.
changes in v6
* fixed check of fputs return, negative on error.
---
 lib/power/meson.build            |   7 +
 lib/power/power_acpi_cpufreq.c   | 192 ++++------------
 lib/power/power_common.c         | 146 ++++++++++++
 lib/power/power_common.h         |  17 ++
 lib/power/power_pstate_cpufreq.c | 374 ++++++++++---------------------
 5 files changed, 335 insertions(+), 401 deletions(-)

diff --git a/lib/power/meson.build b/lib/power/meson.build
index c1097d32f1..74c5f3a294 100644
--- a/lib/power/meson.build
+++ b/lib/power/meson.build
@@ -5,6 +5,13 @@ if not is_linux
     build = false
     reason = 'only supported on Linux'
 endif
+
+# we do some snprintf magic so silence format-nonliteral
+flag_nonliteral = '-Wno-format-nonliteral'
+if cc.has_argument(flag_nonliteral)
+	cflags += flag_nonliteral
+endif
+
 sources = files(
         'guest_channel.c',
         'power_acpi_cpufreq.c',
diff --git a/lib/power/power_acpi_cpufreq.c b/lib/power/power_acpi_cpufreq.c
index 1b8c69cc8b..9ca8d8a8f2 100644
--- a/lib/power/power_acpi_cpufreq.c
+++ b/lib/power/power_acpi_cpufreq.c
@@ -19,41 +19,10 @@
 #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 +129,22 @@ 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(POWER_SYSFILE_AVAIL_FREQ, pi->lcore_id, "r",
+			&f);
+	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 +184,8 @@ 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 +197,24 @@ 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(POWER_SYSFILE_SETSPEED, pi->lcore_id, "rw+",
+			&f);
+	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 +225,9 @@ power_init_for_setting_freq(struct acpi_power_info *pi)
 		}
 	}
 
-out:
-	fclose(f);
+err:
+	if (f != NULL)
+		fclose(f);
 
 	return -1;
 }
@@ -369,54 +311,6 @@ power_acpi_cpufreq_init(unsigned int lcore_id)
 	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)
 {
diff --git a/lib/power/power_common.c b/lib/power/power_common.c
index 67e3318ec7..4deb343dae 100644
--- a/lib/power/power_common.c
+++ b/lib/power/power_common.c
@@ -3,13 +3,20 @@
  */
 
 #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)
@@ -58,3 +65,142 @@ cpufreq_check_scaling_driver(const char *driver_name)
 	 */
 	return 1;
 }
+
+int
+open_core_sysfs_file(const char *template, unsigned int core, const char *mode,
+		FILE **f)
+{
+	char fullpath[PATH_MAX];
+	FILE *tmpf;
+
+	/* silenced -Wformat-nonliteral here */
+	snprintf(fullpath, sizeof(fullpath), template, core);
+	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(POWER_SYSFILE_GOVERNOR, lcore_id, "rw+",
+			&f_governor);
+	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;
+}
diff --git a/lib/power/power_common.h b/lib/power/power_common.h
index fab3ca995a..ef9f5fa855 100644
--- a/lib/power/power_common.h
+++ b/lib/power/power_common.h
@@ -5,9 +5,26 @@
 #ifndef _POWER_COMMON_H_
 #define _POWER_COMMON_H_
 
+#include <inttypes.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(const char *template, unsigned int core,
+			 const char *mode, FILE **f);
+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_ */
diff --git a/lib/power/power_pstate_cpufreq.c b/lib/power/power_pstate_cpufreq.c
index 2cfc54acf3..ed10bd193b 100644
--- a/lib/power/power_pstate_cpufreq.c
+++ b/lib/power/power_pstate_cpufreq.c
@@ -21,46 +21,13 @@
 #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);
-
-		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;
+	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;
+
+	/* open all files we expect to have open */
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi->lcore_id, "r",
+			&f_base_max);
+	if (f_base_max == NULL) {
+		RTE_LOG(ERR, POWER, "failed to open %s\n",
+				POWER_SYSFILE_BASE_MAX_FREQ);
+		goto err;
+	}
+
+	open_core_sysfs_file(POWER_SYSFILE_MIN_FREQ, pi->lcore_id, "rw+",
+			&f_min);
+	if (f_min == NULL) {
+		RTE_LOG(ERR, POWER, "failed to open %s\n",
+				POWER_SYSFILE_MIN_FREQ);
+		goto err;
+	}
+
+	open_core_sysfs_file(POWER_SYSFILE_MAX_FREQ, pi->lcore_id, "rw+",
+			&f_max);
+	if (f_max == NULL) {
+		RTE_LOG(ERR, POWER, "failed to open %s\n",
+				POWER_SYSFILE_MAX_FREQ);
+		goto err;
+	}
+
+	open_core_sysfs_file(POWER_SYSFILE_BASE_FREQ, pi->lcore_id, "r",
+			&f_base);
+	/* base ratio file may not exist in some kernels, so no error check */
+
+	/* 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 {
+		base_ratio = 0;
 	}
 
-	snprintf(fullpath_min, sizeof(fullpath_min), POWER_SYSFILE_MIN_FREQ,
-			pi->lcore_id);
-	f_min = fopen(fullpath_min, "rw+");
-	FOPEN_OR_ERR_RET(f_min, -1);
+	/* 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 */
 
-	snprintf(fullpath_max, sizeof(fullpath_max), 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);
+	/* 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;
 
-	snprintf(fullpath_base, sizeof(fullpath_base), POWER_SYSFILE_BASE_FREQ,
-			pi->lcore_id);
-
-	f_base = fopen(fullpath_base, "r");
-	if (f_base == NULL) {
-		/* No sysfs base_frequency, that's OK, continue without */
-		base_ratio = 0;
-	} 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;
-	}
-
-	/* Add MSR read to detect turbo status */
-
-	if (power_rdmsr(PLATFORM_INFO, &max_non_turbo, pi->lcore_id) < 0) {
-		ret_val = -1;
-		goto out;
-	}
-
 	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 @@ power_set_governor_performance(struct pstate_power_info *pi)
 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 @@ power_set_governor_original(struct pstate_power_info *pi)
 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,
-			pi->lcore_id);
-
-	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);
-
+	/* open all files */
+	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi->lcore_id, "r",
+			&f_max);
+	if (f_max == NULL) {
+		RTE_LOG(ERR, POWER, "failed to open %s\n",
+				POWER_SYSFILE_BASE_MAX_FREQ);
+		goto 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(POWER_SYSFILE_BASE_MIN_FREQ, pi->lcore_id, "r",
+			     &f_min);
+	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 +451,22 @@ 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,
-			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);
+	open_core_sysfs_file(POWER_SYSFILE_CUR_FREQ, pi->lcore_id, "r", &f_cur);
+	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 +485,10 @@ 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;
 }
 
-- 
2.17.1

Re: [dpdk-dev] [PATCH v6 2/2] power: refactor pstate and acpi code

[Burakov, Anatoly]

On 23-Jun-21 1:03 PM, David Hunt wrote:
> From: Anatoly Burakov <anatoly.burakov@intel.com>
> 
> 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>
> 
> ---
> changes in v5
> * fixed bugs raised by Richael Zhuang in review - open file rw+, etc.
> * removed FOPS* and FOPEN* macros, which contained control statements.
> * fixed some checkpatch warnings.
> changes in v6
> * fixed check of fputs return, negative on error.
> ---
>   lib/power/meson.build            |   7 +
>   lib/power/power_acpi_cpufreq.c   | 192 ++++------------
>   lib/power/power_common.c         | 146 ++++++++++++
>   lib/power/power_common.h         |  17 ++
>   lib/power/power_pstate_cpufreq.c | 374 ++++++++++---------------------
>   5 files changed, 335 insertions(+), 401 deletions(-)
> 
> diff --git a/lib/power/meson.build b/lib/power/meson.build
> index c1097d32f1..74c5f3a294 100644
> --- a/lib/power/meson.build
> +++ b/lib/power/meson.build
> @@ -5,6 +5,13 @@ if not is_linux
>       build = false
>       reason = 'only supported on Linux'
>   endif
> +
> +# we do some snprintf magic so silence format-nonliteral
> +flag_nonliteral = '-Wno-format-nonliteral'
> +if cc.has_argument(flag_nonliteral)
> +	cflags += flag_nonliteral
> +endif
> +

I'll do a more thorough review later, but i suspect that we can drop 
this, if we fix the functions to have a GCC printf format attribute:

https://gcc.gnu.org/onlinedocs/gcc-3.2/gcc/Function-Attributes.html

See "format" section. I'm not sure this is supported by other compilers 
though, so maybe it's better to keep it.

-- 
Thanks,
Anatoly

Re: [dpdk-dev] [PATCH v6 2/2] power: refactor pstate and acpi code

[Richael Zhuang]

Hi,
It looks good to me.  I verified on arm platforms and didn't find any problem currently.

BR,
Richael
> -----Original Message-----
> From: David Hunt <david.hunt@intel.com>
> Sent: Wednesday, June 23, 2021 8:04 PM
> To: dev@dpdk.org
> Cc: david.hunt@intel.com; anatoly.burakov@intel.com; Richael Zhuang
> <Richael.Zhuang@arm.com>; stephen@networkplumber.org;
> reshma.pattan@intel.com; nd <nd@arm.com>
> Subject: [PATCH v6 2/2] power: refactor pstate and acpi code
> 
> From: Anatoly Burakov <anatoly.burakov@intel.com>
> 
> 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>
> 
> ---
> changes in v5
> * fixed bugs raised by Richael Zhuang in review - open file rw+, etc.
> * removed FOPS* and FOPEN* macros, which contained control statements.
> * fixed some checkpatch warnings.
> changes in v6
> * fixed check of fputs return, negative on error.
> ---
>  lib/power/meson.build            |   7 +
>  lib/power/power_acpi_cpufreq.c   | 192 ++++------------
>  lib/power/power_common.c         | 146 ++++++++++++
>  lib/power/power_common.h         |  17 ++
>  lib/power/power_pstate_cpufreq.c | 374 ++++++++++---------------------
>  5 files changed, 335 insertions(+), 401 deletions(-)
> 
> diff --git a/lib/power/meson.build b/lib/power/meson.build index
> c1097d32f1..74c5f3a294 100644
> --- a/lib/power/meson.build
> +++ b/lib/power/meson.build
> @@ -5,6 +5,13 @@ if not is_linux
>      build = false
>      reason = 'only supported on Linux'
>  endif
> +
> +# we do some snprintf magic so silence format-nonliteral
> +flag_nonliteral = '-Wno-format-nonliteral'
> +if cc.has_argument(flag_nonliteral)
> +	cflags += flag_nonliteral
> +endif
> +
>  sources = files(
>          'guest_channel.c',
>          'power_acpi_cpufreq.c',
> diff --git a/lib/power/power_acpi_cpufreq.c
> b/lib/power/power_acpi_cpufreq.c index 1b8c69cc8b..9ca8d8a8f2 100644
> --- a/lib/power/power_acpi_cpufreq.c
> +++ b/lib/power/power_acpi_cpufreq.c
> @@ -19,41 +19,10 @@
>  #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_frequen
> cies"
>  #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 +129,22 @@ 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(POWER_SYSFILE_AVAIL_FREQ, pi->lcore_id, "r",
> +			&f);
> +	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 +184,8 @@
> 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 +197,24 @@ 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(POWER_SYSFILE_SETSPEED, pi->lcore_id, "rw+",
> +			&f);
> +	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 +225,9 @@ power_init_for_setting_freq(struct acpi_power_info
> *pi)
>  		}
>  	}
> 
> -out:
> -	fclose(f);
> +err:
> +	if (f != NULL)
> +		fclose(f);
> 
>  	return -1;
>  }
> @@ -369,54 +311,6 @@ power_acpi_cpufreq_init(unsigned int lcore_id)
>  	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)  { diff --git
> a/lib/power/power_common.c b/lib/power/power_common.c index
> 67e3318ec7..4deb343dae 100644
> --- a/lib/power/power_common.c
> +++ b/lib/power/power_common.c
> @@ -3,13 +3,20 @@
>   */
> 
>  #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) @@ -58,3 +65,142
> @@ cpufreq_check_scaling_driver(const char *driver_name)
>  	 */
>  	return 1;
>  }
> +
> +int
> +open_core_sysfs_file(const char *template, unsigned int core, const char
> *mode,
> +		FILE **f)
> +{
> +	char fullpath[PATH_MAX];
> +	FILE *tmpf;
> +
> +	/* silenced -Wformat-nonliteral here */
> +	snprintf(fullpath, sizeof(fullpath), template, core);
> +	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(POWER_SYSFILE_GOVERNOR, lcore_id, "rw+",
> +			&f_governor);
> +	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;
> +}
> diff --git a/lib/power/power_common.h b/lib/power/power_common.h
> index fab3ca995a..ef9f5fa855 100644
> --- a/lib/power/power_common.h
> +++ b/lib/power/power_common.h
> @@ -5,9 +5,26 @@
>  #ifndef _POWER_COMMON_H_
>  #define _POWER_COMMON_H_
> 
> +#include <inttypes.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(const char *template, unsigned int core,
> +			 const char *mode, FILE **f);
> +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_ */
> diff --git a/lib/power/power_pstate_cpufreq.c
> b/lib/power/power_pstate_cpufreq.c
> index 2cfc54acf3..ed10bd193b 100644
> --- a/lib/power/power_pstate_cpufreq.c
> +++ b/lib/power/power_pstate_cpufreq.c
> @@ -21,46 +21,13 @@
>  #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);
> -
> -		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;
> +	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;
> +
> +	/* open all files we expect to have open */
> +	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi-
> >lcore_id, "r",
> +			&f_base_max);
> +	if (f_base_max == NULL) {
> +		RTE_LOG(ERR, POWER, "failed to open %s\n",
> +				POWER_SYSFILE_BASE_MAX_FREQ);
> +		goto err;
> +	}
> +
> +	open_core_sysfs_file(POWER_SYSFILE_MIN_FREQ, pi->lcore_id,
> "rw+",
> +			&f_min);
> +	if (f_min == NULL) {
> +		RTE_LOG(ERR, POWER, "failed to open %s\n",
> +				POWER_SYSFILE_MIN_FREQ);
> +		goto err;
> +	}
> +
> +	open_core_sysfs_file(POWER_SYSFILE_MAX_FREQ, pi->lcore_id,
> "rw+",
> +			&f_max);
> +	if (f_max == NULL) {
> +		RTE_LOG(ERR, POWER, "failed to open %s\n",
> +				POWER_SYSFILE_MAX_FREQ);
> +		goto err;
> +	}
> +
> +	open_core_sysfs_file(POWER_SYSFILE_BASE_FREQ, pi->lcore_id, "r",
> +			&f_base);
> +	/* base ratio file may not exist in some kernels, so no error check */
> +
> +	/* 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 {
> +		base_ratio = 0;
>  	}
> 
> -	snprintf(fullpath_min, sizeof(fullpath_min),
> POWER_SYSFILE_MIN_FREQ,
> -			pi->lcore_id);
> -	f_min = fopen(fullpath_min, "rw+");
> -	FOPEN_OR_ERR_RET(f_min, -1);
> +	/* 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 */
> 
> -	snprintf(fullpath_max, sizeof(fullpath_max),
> 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);
> +	/* 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;
> 
> -	snprintf(fullpath_base, sizeof(fullpath_base),
> POWER_SYSFILE_BASE_FREQ,
> -			pi->lcore_id);
> -
> -	f_base = fopen(fullpath_base, "r");
> -	if (f_base == NULL) {
> -		/* No sysfs base_frequency, that's OK, continue without */
> -		base_ratio = 0;
> -	} 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;
> -	}
> -
> -	/* Add MSR read to detect turbo status */
> -
> -	if (power_rdmsr(PLATFORM_INFO, &max_non_turbo, pi->lcore_id) <
> 0) {
> -		ret_val = -1;
> -		goto out;
> -	}
> -
>  	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 @@ power_set_governor_performance(struct
> pstate_power_info *pi)  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 @@ power_set_governor_original(struct
> pstate_power_info *pi)  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,
> -			pi->lcore_id);
> -
> -	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);
> -
> +	/* open all files */
> +	open_core_sysfs_file(POWER_SYSFILE_BASE_MAX_FREQ, pi-
> >lcore_id, "r",
> +			&f_max);
> +	if (f_max == NULL) {
> +		RTE_LOG(ERR, POWER, "failed to open %s\n",
> +				POWER_SYSFILE_BASE_MAX_FREQ);
> +		goto 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(POWER_SYSFILE_BASE_MIN_FREQ, pi->lcore_id,
> "r",
> +			     &f_min);
> +	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 +451,22 @@ 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,
> -			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);
> +	open_core_sysfs_file(POWER_SYSFILE_CUR_FREQ, pi->lcore_id, "r",
> &f_cur);
> +	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
> +485,10 @@ 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;
>  }
> 
> --
> 2.17.1

Re: [dpdk-dev] [PATCH v6 2/2] power: refactor pstate and acpi code

[David Marchand]

On Wed, Jun 23, 2021 at 2:04 PM David Hunt <david.hunt@intel.com> wrote:
>
> From: Anatoly Burakov <anatoly.burakov@intel.com>
>
> 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>
>
> ---
> changes in v5
> * fixed bugs raised by Richael Zhuang in review - open file rw+, etc.
> * removed FOPS* and FOPEN* macros, which contained control statements.
> * fixed some checkpatch warnings.
> changes in v6
> * fixed check of fputs return, negative on error.
> ---
>  lib/power/meson.build            |   7 +
>  lib/power/power_acpi_cpufreq.c   | 192 ++++------------
>  lib/power/power_common.c         | 146 ++++++++++++
>  lib/power/power_common.h         |  17 ++
>  lib/power/power_pstate_cpufreq.c | 374 ++++++++++---------------------
>  5 files changed, 335 insertions(+), 401 deletions(-)
>
> diff --git a/lib/power/meson.build b/lib/power/meson.build
> index c1097d32f1..74c5f3a294 100644
> --- a/lib/power/meson.build
> +++ b/lib/power/meson.build
> @@ -5,6 +5,13 @@ if not is_linux
>      build = false
>      reason = 'only supported on Linux'
>  endif
> +
> +# we do some snprintf magic so silence format-nonliteral
> +flag_nonliteral = '-Wno-format-nonliteral'
> +if cc.has_argument(flag_nonliteral)
> +       cflags += flag_nonliteral
> +endif
> +

This can be removed with __rte_format_printf tag + API change below.


>  sources = files(
>          'guest_channel.c',
>          'power_acpi_cpufreq.c',

[snip]

> diff --git a/lib/power/power_common.c b/lib/power/power_common.c
> index 67e3318ec7..4deb343dae 100644
> --- a/lib/power/power_common.c
> +++ b/lib/power/power_common.c
> @@ -3,13 +3,20 @@
>   */
>
>  #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)
> @@ -58,3 +65,142 @@ cpufreq_check_scaling_driver(const char *driver_name)
>          */
>         return 1;
>  }

cpufreq_check_scaling_driver can use open_core_sysfs_file, right?


> +
> +int
> +open_core_sysfs_file(const char *template, unsigned int core, const char *mode,
> +               FILE **f)
> +{
> +       char fullpath[PATH_MAX];
> +       FILE *tmpf;
> +
> +       /* silenced -Wformat-nonliteral here */
> +       snprintf(fullpath, sizeof(fullpath), template, core);
> +       tmpf = fopen(fullpath, mode);
> +       *f = tmpf;
> +       if (tmpf == NULL)
> +               return -1;
> +
> +       return 0;
> +}


@@ -67,14 +67,15 @@ cpufreq_check_scaling_driver(const char *driver_name)
 }

 int
-open_core_sysfs_file(const char *template, unsigned int core, const char *mode,
-               FILE **f)
+open_core_sysfs_file(FILE **f, const char *mode, const char *format, ...)
 {
        char fullpath[PATH_MAX];
+       va_list ap;
        FILE *tmpf;

-       /* silenced -Wformat-nonliteral here */
-       snprintf(fullpath, sizeof(fullpath), template, core);
+       va_start(ap, format);
+       vsnprintf(fullpath, sizeof(fullpath), format, ap);
+       va_end(ap);
        tmpf = fopen(fullpath, mode);
        *f = tmpf;
        if (tmpf == NULL)



With declaration in .h as:

@@ -7,6 +7,8 @@

 #include <inttypes.h>

+#include <rte_common.h>
+
 #define RTE_POWER_INVALID_FREQ_INDEX (~0)


@@ -21,8 +23,8 @@
 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(const char *template, unsigned int core,
-                        const char *mode, FILE **f);
+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);


This leaves the possibility to use any kind of formats.
And to be honest, I did not manage to make gcc happy otherwise (even
when passing __rte_format_printf(3, 0)).


-- 
David Marchand

Re: [dpdk-dev] [PATCH v6 2/2] power: refactor pstate and acpi code

[David Hunt]

On 8/7/2021 1:49 PM, David Marchand wrote:
> On Wed, Jun 23, 2021 at 2:04 PM David Hunt <david.hunt@intel.com> wrote:
>> From: Anatoly Burakov <anatoly.burakov@intel.com>
>>
>> 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>
>>
>> ---
>> changes in v5
>> * fixed bugs raised by Richael Zhuang in review - open file rw+, etc.
>> * removed FOPS* and FOPEN* macros, which contained control statements.
>> * fixed some checkpatch warnings.
>> changes in v6
>> * fixed check of fputs return, negative on error.
>> ---
>>   lib/power/meson.build            |   7 +
>>   lib/power/power_acpi_cpufreq.c   | 192 ++++------------
>>   lib/power/power_common.c         | 146 ++++++++++++
>>   lib/power/power_common.h         |  17 ++
>>   lib/power/power_pstate_cpufreq.c | 374 ++++++++++---------------------
>>   5 files changed, 335 insertions(+), 401 deletions(-)
>>
>> diff --git a/lib/power/meson.build b/lib/power/meson.build
>> index c1097d32f1..74c5f3a294 100644
>> --- a/lib/power/meson.build
>> +++ b/lib/power/meson.build
>> @@ -5,6 +5,13 @@ if not is_linux
>>       build = false
>>       reason = 'only supported on Linux'
>>   endif
>> +
>> +# we do some snprintf magic so silence format-nonliteral
>> +flag_nonliteral = '-Wno-format-nonliteral'
>> +if cc.has_argument(flag_nonliteral)
>> +       cflags += flag_nonliteral
>> +endif
>> +
> This can be removed with __rte_format_printf tag + API change below.
>
>
>>   sources = files(
>>           'guest_channel.c',
>>           'power_acpi_cpufreq.c',
> [snip]
>
>> diff --git a/lib/power/power_common.c b/lib/power/power_common.c
>> index 67e3318ec7..4deb343dae 100644
>> --- a/lib/power/power_common.c
>> +++ b/lib/power/power_common.c
>> @@ -3,13 +3,20 @@
>>    */
>>
>>   #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)
>> @@ -58,3 +65,142 @@ cpufreq_check_scaling_driver(const char *driver_name)
>>           */
>>          return 1;
>>   }
> cpufreq_check_scaling_driver can use open_core_sysfs_file, right?
>
>
>> +
>> +int
>> +open_core_sysfs_file(const char *template, unsigned int core, const char *mode,
>> +               FILE **f)
>> +{
>> +       char fullpath[PATH_MAX];
>> +       FILE *tmpf;
>> +
>> +       /* silenced -Wformat-nonliteral here */
>> +       snprintf(fullpath, sizeof(fullpath), template, core);
>> +       tmpf = fopen(fullpath, mode);
>> +       *f = tmpf;
>> +       if (tmpf == NULL)
>> +               return -1;
>> +
>> +       return 0;
>> +}
>
> @@ -67,14 +67,15 @@ cpufreq_check_scaling_driver(const char *driver_name)
>   }
>
>   int
> -open_core_sysfs_file(const char *template, unsigned int core, const char *mode,
> -               FILE **f)
> +open_core_sysfs_file(FILE **f, const char *mode, const char *format, ...)
>   {
>          char fullpath[PATH_MAX];
> +       va_list ap;
>          FILE *tmpf;
>
> -       /* silenced -Wformat-nonliteral here */
> -       snprintf(fullpath, sizeof(fullpath), template, core);
> +       va_start(ap, format);
> +       vsnprintf(fullpath, sizeof(fullpath), format, ap);
> +       va_end(ap);
>          tmpf = fopen(fullpath, mode);
>          *f = tmpf;
>          if (tmpf == NULL)
>
>
>
> With declaration in .h as:
>
> @@ -7,6 +7,8 @@
>
>   #include <inttypes.h>
>
> +#include <rte_common.h>
> +
>   #define RTE_POWER_INVALID_FREQ_INDEX (~0)
>
>
> @@ -21,8 +23,8 @@
>   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(const char *template, unsigned int core,
> -                        const char *mode, FILE **f);
> +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);
>
>
> This leaves the possibility to use any kind of formats.
> And to be honest, I did not manage to make gcc happy otherwise (even
> when passing __rte_format_printf(3, 0)).


Thanks, David, good suggestions.  I'll make those changes and respin.

Rgds,
Dave.


>

[dpdk-dev] [PATCH v7 1/2] power: don't use rte prefix in internal code

[David Hunt]

From: Anatoly Burakov <anatoly.burakov@intel.com>

Currently, ACPI code uses rte_power_info as the struct name, which
gives the appearance that this is an externally visible API. Fix to
use internal namespace.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: David Hunt <david.hunt@intel.com>
---
 lib/power/power_acpi_cpufreq.c | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/lib/power/power_acpi_cpufreq.c b/lib/power/power_acpi_cpufreq.c
index d028a9947f..1b8c69cc8b 100644
--- a/lib/power/power_acpi_cpufreq.c
+++ b/lib/power/power_acpi_cpufreq.c
@@ -78,7 +78,7 @@ enum power_state {
 /**
  * Power info per lcore.
  */
-struct rte_power_info {
+struct acpi_power_info {
 	unsigned int lcore_id;                   /**< Logical core id */
 	uint32_t freqs[RTE_MAX_LCORE_FREQS]; /**< Frequency array */
 	uint32_t nb_freqs;                   /**< number of available freqs */
@@ -90,14 +90,14 @@ struct rte_power_info {
 	uint16_t turbo_enable;               /**< Turbo Boost enable/disable */
 } __rte_cache_aligned;
 
-static struct rte_power_info lcore_power_info[RTE_MAX_LCORE];
+static struct acpi_power_info lcore_power_info[RTE_MAX_LCORE];
 
 /**
  * It is to set specific freq for specific logical core, according to the index
  * of supported frequencies.
  */
 static int
-set_freq_internal(struct rte_power_info *pi, uint32_t idx)
+set_freq_internal(struct acpi_power_info *pi, uint32_t idx)
 {
 	if (idx >= RTE_MAX_LCORE_FREQS || idx >= pi->nb_freqs) {
 		RTE_LOG(ERR, POWER, "Invalid frequency index %u, which "
@@ -133,7 +133,7 @@ set_freq_internal(struct rte_power_info *pi, uint32_t idx)
  * governor will be saved for rolling back.
  */
 static int
-power_set_governor_userspace(struct rte_power_info *pi)
+power_set_governor_userspace(struct acpi_power_info *pi)
 {
 	FILE *f;
 	int ret = -1;
@@ -189,7 +189,7 @@ power_set_governor_userspace(struct rte_power_info *pi)
  * sys file.
  */
 static int
-power_get_available_freqs(struct rte_power_info *pi)
+power_get_available_freqs(struct acpi_power_info *pi)
 {
 	FILE *f;
 	int ret = -1, i, count;
@@ -259,7 +259,7 @@ power_get_available_freqs(struct rte_power_info *pi)
  * It is to fopen the sys file for the future setting the lcore frequency.
  */
 static int
-power_init_for_setting_freq(struct rte_power_info *pi)
+power_init_for_setting_freq(struct acpi_power_info *pi)
 {
 	FILE *f;
 	char fullpath[PATH_MAX];
@@ -299,7 +299,7 @@ power_acpi_cpufreq_check_supported(void)
 int
 power_acpi_cpufreq_init(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 	uint32_t exp_state;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
@@ -374,7 +374,7 @@ power_acpi_cpufreq_init(unsigned int lcore_id)
  * needed by writing the sys file.
  */
 static int
-power_set_governor_original(struct rte_power_info *pi)
+power_set_governor_original(struct acpi_power_info *pi)
 {
 	FILE *f;
 	int ret = -1;
@@ -420,7 +420,7 @@ power_set_governor_original(struct rte_power_info *pi)
 int
 power_acpi_cpufreq_exit(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 	uint32_t exp_state;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
@@ -475,7 +475,7 @@ power_acpi_cpufreq_exit(unsigned int lcore_id)
 uint32_t
 power_acpi_cpufreq_freqs(unsigned int lcore_id, uint32_t *freqs, uint32_t num)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -522,7 +522,7 @@ power_acpi_cpufreq_set_freq(unsigned int lcore_id, uint32_t index)
 int
 power_acpi_cpufreq_freq_down(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -540,7 +540,7 @@ power_acpi_cpufreq_freq_down(unsigned int lcore_id)
 int
 power_acpi_cpufreq_freq_up(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -581,7 +581,7 @@ power_acpi_cpufreq_freq_max(unsigned int lcore_id)
 int
 power_acpi_cpufreq_freq_min(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -598,7 +598,7 @@ power_acpi_cpufreq_freq_min(unsigned int lcore_id)
 int
 power_acpi_turbo_status(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -614,7 +614,7 @@ power_acpi_turbo_status(unsigned int lcore_id)
 int
 power_acpi_enable_turbo(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -647,7 +647,7 @@ power_acpi_enable_turbo(unsigned int lcore_id)
 int
 power_acpi_disable_turbo(unsigned int lcore_id)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
@@ -674,7 +674,7 @@ power_acpi_disable_turbo(unsigned int lcore_id)
 int power_acpi_get_capabilities(unsigned int lcore_id,
 		struct rte_power_core_capabilities *caps)
 {
-	struct rte_power_info *pi;
+	struct acpi_power_info *pi;
 
 	if (lcore_id >= RTE_MAX_LCORE) {
 		RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
-- 
2.17.1

[dpdk-dev] [PATCH v7 2/2] power: refactor pstate and acpi code

[David Hunt]

From: Anatoly Burakov <anatoly.burakov@intel.com>

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>

---
changes in v5
* fixed bugs raised by Richael Zhuang in review - open file rw+, etc.
* removed FOPS* and FOPEN* macros, which contained control statements.
* fixed some checkpatch warnings.
changes in v6
* fixed check of fputs return, negative on error.
changes in v7
* Cleaned up meson file by removing warning-nonliteral hack (DavidM)
  and make associated suggested changes.
---
 lib/power/meson.build            |   1 +
 lib/power/power_acpi_cpufreq.c   | 190 ++++-------------
 lib/power/power_common.c         | 153 ++++++++++++-
 lib/power/power_common.h         |  19 ++
 lib/power/power_pstate_cpufreq.c | 355 ++++++++++---------------------
 5 files changed, 323 insertions(+), 395 deletions(-)

diff --git a/lib/power/meson.build b/lib/power/meson.build
index c1097d32f1..7253f1b325 100644
--- a/lib/power/meson.build
+++ b/lib/power/meson.build
@@ -5,6 +5,7 @@ if not is_linux
     build = false
     reason = 'only supported on Linux'
 endif
+
 sources = files(
         'guest_channel.c',
         'power_acpi_cpufreq.c',
diff --git a/lib/power/power_acpi_cpufreq.c b/lib/power/power_acpi_cpufreq.c
index 1b8c69cc8b..1e8aeb8403 100644
--- a/lib/power/power_acpi_cpufreq.c
+++ b/lib/power/power_acpi_cpufreq.c
@@ -19,41 +19,10 @@
 #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 @@ power_acpi_cpufreq_init(unsigned int lcore_id)
 	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)
 {
diff --git a/lib/power/power_common.c b/lib/power/power_common.c
index 67e3318ec7..f5ab2f59ac 100644
--- a/lib/power/power_common.c
+++ b/lib/power/power_common.c
@@ -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 +62,144 @@ 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;
+}
diff --git a/lib/power/power_common.h b/lib/power/power_common.h
index fab3ca995a..0b264edfa5 100644
--- a/lib/power/power_common.h
+++ b/lib/power/power_common.h
@@ -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_ */
diff --git a/lib/power/power_pstate_cpufreq.c b/lib/power/power_pstate_cpufreq.c
index 2cfc54acf3..ba28ddcfca 100644
--- a/lib/power/power_pstate_cpufreq.c
+++ b/lib/power/power_pstate_cpufreq.c
@@ -21,46 +21,13 @@
 #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 @@ power_set_governor_performance(struct pstate_power_info *pi)
 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 @@ power_set_governor_original(struct pstate_power_info *pi)
 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;
 }
 
-- 
2.17.1

Re: [dpdk-dev] [PATCH v7 1/2] power: don't use rte prefix in internal code

[David Marchand]

On Thu, Jul 8, 2021 at 5:39 PM David Hunt <david.hunt@intel.com> wrote:
>
> From: Anatoly Burakov <anatoly.burakov@intel.com>
>
> Currently, ACPI code uses rte_power_info as the struct name, which
> gives the appearance that this is an externally visible API. Fix to
> use internal namespace.
>
> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> Acked-by: David Hunt <david.hunt@intel.com>

Series applied.


-- 
David Marchand