path: root/tools/perf/util/pmu.c

#include <linux/list.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
#include <dirent.h>
#include "fs.h"
#include <locale.h>
#include "util.h"
#include "pmu.h"
#include "parse-events.h"
#include "cpumap.h"

#define UNIT_MAX_LEN	31 /* max length for event unit name */

struct perf_pmu_alias {
	char *name;
	struct list_head terms;
	struct list_head list;
	char unit[UNIT_MAX_LEN+1];
	double scale;
};

struct perf_pmu_format {
	char *name;
	int value;
	DECLARE_BITMAP(bits, PERF_PMU_FORMAT_BITS);
	struct list_head list;
};

#define EVENT_SOURCE_DEVICE_PATH "/bus/event_source/devices/"

int perf_pmu_parse(struct list_head *list, char *name);
extern FILE *perf_pmu_in;

static LIST_HEAD(pmus);

/*
 * Parse & process all the sysfs attributes located under
 * the directory specified in 'dir' parameter.
 */
int perf_pmu__format_parse(char *dir, struct list_head *head)
{
	struct dirent *evt_ent;
	DIR *format_dir;
	int ret = 0;

	format_dir = opendir(dir);
	if (!format_dir)
		return -EINVAL;

	while (!ret && (evt_ent = readdir(format_dir))) {
		char path[PATH_MAX];
		char *name = evt_ent->d_name;
		FILE *file;

		if (!strcmp(name, ".") || !strcmp(name, ".."))
			continue;

		snprintf(path, PATH_MAX, "%s/%s", dir, name);

		ret = -EINVAL;
		file = fopen(path, "r");
		if (!file)
			break;

		perf_pmu_in = file;
		ret = perf_pmu_parse(head, name);
		fclose(file);
	}

	closedir(format_dir);
	return ret;
}

/*
 * Reading/parsing the default pmu format definition, which should be
 * located at:
 * /sys/bus/event_source/devices/<dev>/format as sysfs group attributes.
 */
static int pmu_format(const char *name, struct list_head *format)
{
	struct stat st;
	char path[PATH_MAX];
	const char *sysfs = sysfs__mountpoint();

	if (!sysfs)
		return -1;

	snprintf(path, PATH_MAX,
		 "%s" EVENT_SOURCE_DEVICE_PATH "%s/format", sysfs, name);

	if (stat(path, &st) < 0)
		return 0;	/* no error if format does not exist */

	if (perf_pmu__format_parse(path, format))
		return -1;

	return 0;
}

static int perf_pmu__parse_scale(struct perf_pmu_alias *alias, char *dir, char *name)
{
	struct stat st;
	ssize_t sret;
	char scale[128];
	int fd, ret = -1;
	char path[PATH_MAX];
	const char *lc;

	snprintf(path, PATH_MAX, "%s/%s.scale", dir, name);

	fd = open(path, O_RDONLY);
	if (fd == -1)
		return -1;

	if (fstat(fd, &st) < 0)
		goto error;

	sret = read(fd, scale, sizeof(scale)-1);
	if (sret < 0)
		goto error;

	scale[sret] = '\0';
	/*
	 * save current locale
	 */
	lc = setlocale(LC_NUMERIC, NULL);

	/*
	 * force to C locale to ensure kernel
	 * scale string is converted correctly.
	 * kernel uses default C locale.
	 */
	setlocale(LC_NUMERIC, "C");

	alias->scale = strtod(scale, NULL);

	/* restore locale */
	setlocale(LC_NUMERIC, lc);

	ret = 0;
error:
	close(fd);
	return ret;
}

static int perf_pmu__parse_unit(struct perf_pmu_alias *alias, char *dir, char *name)
{
	char path[PATH_MAX];
	ssize_t sret;
	int fd;

	snprintf(path, PATH_MAX, "%s/%s.unit", dir, name);

	fd = open(path, O_RDONLY);
	if (fd == -1)
		return -1;

		sret = read(fd, alias->unit, UNIT_MAX_LEN);
	if (sret < 0)
		goto error;

	close(fd);

	alias->unit[sret] = '\0';

	return 0;
error:
	close(fd);
	alias->unit[0] = '\0';
	return -1;
}

static int perf_pmu__new_alias(struct list_head *list, char *dir, char *name, FILE *file)
{
	struct perf_pmu_alias *alias;
	char buf[256];
	int ret;

	ret = fread(buf, 1, sizeof(buf), file);
	if (ret == 0)
		return -EINVAL;
	buf[ret] = 0;

	alias = malloc(sizeof(*alias));
	if (!alias)
		return -ENOMEM;

	INIT_LIST_HEAD(&alias->terms);
	alias->scale = 1.0;
	alias->unit[0] = '\0';

	ret = parse_events_terms(&alias->terms, buf);
	if (ret) {
		free(alias);
		return ret;
	}

	alias->name = strdup(name);
	/*
	 * load unit name and scale if available
	 */
	perf_pmu__parse_unit(alias, dir, name);
	perf_pmu__parse_scale(alias, dir, name);

	list_add_tail(&alias->list, list