X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=lib%2Fpower%2Fpower_common.c;h=1e09facb863f29a723a74be4955638ec0fd5df5a;hb=080c84cde42fd06443b02f495cd0397a490a1f71;hp=67e3318ec71d69db06c09ea1011975e764f1a2d9;hpb=99a2dd955fba6e4cc23b77d590a033650ced9c45;p=dpdk.git

diff --git a/lib/power/power_common.c b/lib/power/power_common.c
index 67e3318ec7..1e09facb86 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 +62,143 @@ cpufreq_check_scaling_driver(const char *driver_name)
 	 */
 	return 1;
 }
+
+int
+open_core_sysfs_file(FILE **f, const char *mode, const char *format, ...)
+{
+	char fullpath[PATH_MAX];
+	va_list ap;
+	FILE *tmpf;
+
+	va_start(ap, format);
+	vsnprintf(fullpath, sizeof(fullpath), format, ap);
+	va_end(ap);
+	tmpf = fopen(fullpath, mode);
+	*f = tmpf;
+	if (tmpf == NULL)
+		return -1;
+
+	return 0;
+}
+
+int
+read_core_sysfs_u32(FILE *f, uint32_t *val)
+{
+	char buf[BUFSIZ];
+	uint32_t fval;
+	char *s;
+
+	s = fgets(buf, sizeof(buf), f);
+	if (s == NULL)
+		return -1;
+
+	/* fgets puts null terminator in, but do this just in case */
+	buf[BUFSIZ - 1] = '\0';
+
+	/* strip off any terminating newlines */
+	*strchrnul(buf, '\n') = '\0';
+
+	fval = strtoul(buf, NULL, POWER_CONVERT_TO_DECIMAL);
+
+	/* write the value */
+	*val = fval;
+
+	return 0;
+}
+
+int
+read_core_sysfs_s(FILE *f, char *buf, unsigned int len)
+{
+	char *s;
+
+	s = fgets(buf, len, f);
+	if (s == NULL)
+		return -1;
+
+	/* fgets puts null terminator in, but do this just in case */
+	buf[len - 1] = '\0';
+
+	/* strip off any terminating newlines */
+	*strchrnul(buf, '\n') = '\0';
+
+	return 0;
+}
+
+int
+write_core_sysfs_s(FILE *f, const char *str)
+{
+	int ret;
+
+	ret = fseek(f, 0, SEEK_SET);
+	if (ret != 0)
+		return -1;
+
+	ret = fputs(str, f);
+	if (ret < 0)
+		return -1;
+
+	/* flush the output */
+	ret = fflush(f);
+	if (ret != 0)
+		return -1;
+
+	return 0;
+}
+
+/**
+ * It is to check the current scaling governor by reading sys file, and then
+ * set it into 'performance' if it is not by writing the sys file. The original
+ * governor will be saved for rolling back.
+ */
+int
+power_set_governor(unsigned int lcore_id, const char *new_governor,
+		char *orig_governor, size_t orig_governor_len)
+{
+	FILE *f_governor = NULL;
+	int ret = -1;
+	char buf[BUFSIZ];
+
+	open_core_sysfs_file(&f_governor, "rw+", POWER_SYSFILE_GOVERNOR,
+			lcore_id);
+	if (f_governor == NULL) {
+		RTE_LOG(ERR, POWER, "failed to open %s\n",
+				POWER_SYSFILE_GOVERNOR);
+		goto out;
+	}
+
+	ret = read_core_sysfs_s(f_governor, buf, sizeof(buf));
+	if (ret < 0) {
+		RTE_LOG(ERR, POWER, "Failed to read %s\n",
+				POWER_SYSFILE_GOVERNOR);
+		goto out;
+	}
+
+	/* Save the original governor, if it was provided */
+	if (orig_governor)
+		rte_strscpy(orig_governor, buf, orig_governor_len);
+
+	/* Check if current governor is already what we want */
+	if (strcmp(buf, new_governor) == 0) {
+		ret = 0;
+		POWER_DEBUG_TRACE("Power management governor of lcore %u is "
+				"already %s\n", lcore_id, new_governor);
+		goto out;
+	}
+
+	/* Write the new governor */
+	ret = write_core_sysfs_s(f_governor, new_governor);
+	if (ret < 0) {
+		RTE_LOG(ERR, POWER, "Failed to write %s\n",
+				POWER_SYSFILE_GOVERNOR);
+		goto out;
+	}
+
+	ret = 0;
+	RTE_LOG(INFO, POWER, "Power management governor of lcore %u has been "
+			"set to '%s' successfully\n", lcore_id, new_governor);
+out:
+	if (f_governor != NULL)
+		fclose(f_governor);
+
+	return ret;
+}