1 files changed, 299 insertions, 0 deletions
diff --git a/tools/power/cpupower/lib/powercap.c b/tools/power/cpupower/lib/powercap.c
new file mode 100644
index 000000000000..a7a59c6bacda
--- /dev/null
+++ b/tools/power/cpupower/lib/powercap.c
@@ -0,0 +1,299 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  (C) 2016 SUSE Software Solutions GmbH
+ *           Thomas Renninger <trenn@suse.de>
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <dirent.h>
+
+#include "powercap.h"
+
+static unsigned int sysfs_read_file(const char *path, char *buf, size_t buflen)
+{
+	int fd;
+	ssize_t numread;
+
+	fd = open(path, O_RDONLY);
+	if (fd == -1)
+		return 0;
+
+	numread = read(fd, buf, buflen - 1);
+	if (numread < 1) {
+		close(fd);
+		return 0;
+	}
+
+	buf[numread] = '\0';
+	close(fd);
+
+	return (unsigned int) numread;
+}
+
+static int sysfs_get_enabled(char *path, int *mode)
+{
+	int fd;
+	char yes_no;
+	int ret = 0;
+
+	*mode = 0;
+
+	fd = open(path, O_RDONLY);
+	if (fd == -1) {
+		ret = -1;
+		goto out;
+	}
+
+	if (read(fd, &yes_no, 1) != 1) {
+		ret = -1;
+		goto out_close;
+	}
+
+	if (yes_no == '1') {
+		*mode = 1;
+		goto out_close;
+	} else if (yes_no == '0') {
+		goto out_close;
+	} else {
+		ret = -1;
+		goto out_close;
+	}
+out_close:
+	close(fd);
+out:
+	return ret;
+}
+
+int powercap_get_enabled(int *mode)
+{
+	char path[SYSFS_PATH_MAX] = PATH_TO_POWERCAP "/intel-rapl/enabled";
+
+	return sysfs_get_enabled(path, mode);
+}
+
+/*
+ * Hardcoded, because rapl is the only powercap implementation
+- * this needs to get more generic if more powercap implementations
+ * should show up
+ */
+int powercap_get_driver(char *driver, int buflen)
+{
+	char file[SYSFS_PATH_MAX] = PATH_TO_RAPL;
+
+	struct stat statbuf;
+
+	if (stat(file, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode)) {
+		driver = "";
+		return -1;
+	} else if (buflen > 10) {
+		strcpy(driver, "intel-rapl");
+		return 0;
+	} else
+		return -1;
+}
+
+enum powercap_get64 {
+	GET_ENERGY_UJ,
+	GET_MAX_ENERGY_RANGE_UJ,
+	GET_POWER_UW,
+	GET_MAX_POWER_RANGE_UW,
+	MAX_GET_64_FILES
+};
+
+static const char *powercap_get64_files[MAX_GET_64_FILES] = {
+	[GET_POWER_UW] = "power_uw",
+	[GET_MAX_POWER_RANGE_UW] = "max_power_range_uw",
+	[GET_ENERGY_UJ] = "energy_uj",
+	[GET_MAX_ENERGY_RANGE_UJ] = "max_energy_range_uj",
+};
+
+static int sysfs_powercap_get64_val(struct powercap_zone *zone,
+				      enum powercap_get64 which,
+				      uint64_t *val)
+{
+	char file[SYSFS_PATH_MAX] = PATH_TO_POWERCAP "/";
+	int ret;
+	char buf[MAX_LINE_LEN];
+
+	strcat(file, zone->sys_name);
+	strcat(file, "/");
+	strcat(file, powercap_get64_files[which]);
+
+	ret = sysfs_read_file(file, buf, MAX_LINE_LEN);
+	if (ret < 0)
+		return ret;
+	if (ret == 0)
+		return -1;
+
+	*val = strtoll(buf, NULL, 10);
+	return 0;
+}
+
+int powercap_get_max_energy_range_uj(struct powercap_zone *zone, uint64_t *val)
+{
+	return sysfs_powercap_get64_val(zone, GET_MAX_ENERGY_RANGE_UJ, val);
+}
+
+int powercap_get_energy_uj(struct powercap_zone *zone, uint64_t *val)
+{
+	return sysfs_powercap_get64_val(zone, GET_ENERGY_UJ, val);
+}
+
+int powercap_get_max_power_range_uw(struct powercap_zone *zone, uint64_t *val)
+{
+	return sysfs_powercap_get64_val(zone, GET_MAX_POWER_RANGE_UW, val);
+}
+
+int powercap_get_power_uw(struct powercap_zone *zone, uint64_t *val)
+{
+	return sysfs_powercap_get64_val(zone, GET_POWER_UW, val);
+}
+
+int powercap_zone_get_enabled(struct powercap_zone *zone, int *mode)
+{
+	char path[SYSFS_PATH_MAX] = PATH_TO_POWERCAP;
+
+	if ((strlen(PATH_TO_POWERCAP) + strlen(zone->sys_name)) +
+	    strlen("/enabled") + 1 >= SYSFS_PATH_MAX)
+		return -1;
+
+	strcat(path, "/");
+	strcat(path, zone->sys_name);
+	strcat(path, "/enabled");
+
+	return sysfs_get_enabled(path, mode);
+}
+
+int powercap_zone_set_enabled(struct powercap_zone *zone, int mode)
+{
+	/* To be done if needed */
+	return 0;
+}
+
+
+int powercap_read_zone(struct powercap_zone *zone)
+{
+	struct dirent *dent;
+	DIR *zone_dir;
+	char sysfs_dir[SYSFS_PATH_MAX] = PATH_TO_POWERCAP;
+	struct powercap_zone *child_zone;
+	char file[SYSFS_PATH_MAX] = PATH_TO_POWERCAP;
+	int i, ret = 0;
+	uint64_t val = 0;
+
+	strcat(sysfs_dir, "/");
+	strcat(sysfs_dir, zone->sys_name);
+
+	zone_dir = opendir(sysfs_dir);
+	if (zone_dir == NULL)
+		return -1;
+
+	strcat(file, "/");
+	strcat(file, zone->sys_name);
+	strcat(file, "/name");
+	sysfs_read_file(file, zone->name, MAX_LINE_LEN);
+	if (zone->parent)
+		zone->tree_depth = zone->parent->tree_depth + 1;
+	ret = powercap_get_energy_uj(zone, &val);
+	if (ret == 0)
+		zone->has_energy_uj = 1;
+	ret = powercap_get_power_uw(zone, &val);
+	if (ret == 0)
+		zone->has_power_uw = 1;
+
+	while ((dent = readdir(zone_dir)) != NULL) {
+		struct stat st;
+
+		if (strcmp(dent->d_name, ".") == 0 || strcmp(dent->d_name, "..") == 0)
+			continue;
+
+		if (stat(dent->d_name, &st) != 0 || !S_ISDIR(st.st_mode))
+			if (fstatat(dirfd(zone_dir), dent->d_name, &st, 0) < 0)
+				continue;
+
+		if (strncmp(dent->d_name, "intel-rapl:", 11) != 0)
+			continue;
+
+		child_zone = calloc(1, sizeof(struct powercap_zone));
+		if (child_zone == NULL)
+			return -1;
+		for (i = 0; i < POWERCAP_MAX_CHILD_ZONES; i++) {
+			if (zone->children[i] == NULL) {
+				zone->children[i] = child_zone;
+				break;
+			}
+			if (i == POWERCAP_MAX_CHILD_ZONES - 1) {
+				free(child_zone);
+				fprintf(stderr, "Reached POWERCAP_MAX_CHILD_ZONES %d\n",
+				       POWERCAP_MAX_CHILD_ZONES);
+				return -1;
+			}
+		}
+		strcpy(child_zone->sys_name, zone->sys_name);
+		strcat(child_zone->sys_name, "/");
+		strcat(child_zone->sys_name, dent->d_name);
+		child_zone->parent = zone;
+		if (zone->tree_depth >= POWERCAP_MAX_TREE_DEPTH) {
+			fprintf(stderr, "Maximum zone hierarchy depth[%d] reached\n",
+				POWERCAP_MAX_TREE_DEPTH);
+			ret = -1;
+			break;
+		}
+		powercap_read_zone(child_zone);
+	}
+	closedir(zone_dir);
+	return ret;
+}
+
+struct powercap_zone *powercap_init_zones(void)
+{
+	int enabled;
+	struct powercap_zone *root_zone;
+	int ret;
+	char file[SYSFS_PATH_MAX] = PATH_TO_RAPL "/enabled";
+
+	ret = sysfs_get_enabled(file, &enabled);
+
+	if (ret)
+		return NULL;
+
+	if (!enabled)
+		return NULL;
+
+	root_zone = calloc(1, sizeof(struct powercap_zone));
+	if (!root_zone)
+		return NULL;
+
+	strcpy(root_zone->sys_name, "intel-rapl/intel-rapl:0");
+
+	powercap_read_zone(root_zone);
+
+	return root_zone;
+}
+
+/* Call function *f on the passed zone and all its children */
+
+int powercap_walk_zones(struct powercap_zone *zone,
+			int (*f)(struct powercap_zone *zone))
+{
+	int i, ret;
+
+	if (!zone)
+		return -1;
+
+	ret = f(zone);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < POWERCAP_MAX_CHILD_ZONES; i++) {
+		if (zone->children[i] != NULL)
+			powercap_walk_zones(zone->children[i], f);
+	}
+	return 0;
+}