path: root/tools/tracing/rtla/src/utils.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
 */

#define _GNU_SOURCE
#ifdef HAVE_LIBCPUPOWER_SUPPORT
#include <cpuidle.h>
#endif /* HAVE_LIBCPUPOWER_SUPPORT */
#include <dirent.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <sched.h>
#include <stdio.h>

#include "utils.h"

#define MAX_MSG_LENGTH	1024
int config_debug;

/*
 * err_msg - print an error message to the stderr
 */
void err_msg(const char *fmt, ...)
{
	char message[MAX_MSG_LENGTH];
	va_list ap;

	va_start(ap, fmt);
	vsnprintf(message, sizeof(message), fmt, ap);
	va_end(ap);

	fprintf(stderr, "%s", message);
}

/*
 * debug_msg - print a debug message to stderr if debug is set
 */
void debug_msg(const char *fmt, ...)
{
	char message[MAX_MSG_LENGTH];
	va_list ap;

	if (!config_debug)
		return;

	va_start(ap, fmt);
	vsnprintf(message, sizeof(message), fmt, ap);
	va_end(ap);

	fprintf(stderr, "%s", message);
}

/*
 * get_llong_from_str - get a long long int from a string
 */
long long get_llong_from_str(char *start)
{
	long long value;
	char *end;

	errno = 0;
	value = strtoll(start, &end, 10);
	if (errno || start == end)
		return -1;

	return value;
}

/*
 * get_duration - fill output with a human readable duration since start_time
 */
void get_duration(time_t start_time, char *output, int output_size)
{
	time_t now = time(NULL);
	struct tm *tm_info;
	time_t duration;

	duration = difftime(now, start_time);
	tm_info = gmtime(&duration);

	snprintf(output, output_size, "%3d %02d:%02d:%02d",
			tm_info->tm_yday,
			tm_info->tm_hour,
			tm_info->tm_min,
			tm_info->tm_sec);
}

/*
 * parse_cpu_set - parse a cpu_list filling cpu_set_t argument
 *
 * Receives a cpu list, like 1-3,5 (cpus 1, 2, 3, 5), and then set
 * filling cpu_set_t argument.
 *
 * Returns 1 on success, 0 otherwise.
 */
int parse_cpu_set(char *cpu_list, cpu_set_t *set)
{
	const char *p;
	int end_cpu;
	int nr_cpus;
	int cpu;
	int i;

	CPU_ZERO(set);

	nr_cpus = sysconf(_SC_NPROCESSORS_CONF);

	for (p = cpu_list; *p; ) {
		cpu = atoi(p);
		if (cpu < 0 || (!cpu && *p != '0') || cpu >= nr_cpus)
			goto err;

		while (isdigit(*p))
			p++;
		if (*p == '-') {
			p++;
			end_cpu = atoi(p);
			if (end_cpu < cpu || (!end_cpu && *p != '0') || end_cpu >= nr_cpus)
				goto err;
			while (isdigit(*p))
				p++;
		} else
			end_cpu = cpu;

		if (cpu == end_cpu) {
			debug_msg("cpu_set: adding cpu %d\n", cpu);
			CPU_SET(cpu, set);
		} else {
			for (i = cpu; i <= end_cpu; i++) {
				debug_msg("cpu_set: adding cpu %d\n", i);
				CPU_SET(i, set);
			}
		}

		if (*p == ',')
			p++;
	}

	return 0;
err:
	debug_msg("Error parsing the cpu set %s\n", cpu_list);
	return 1;
}

/*
 * parse_duration - parse duration with s/m/h/d suffix converting it to seconds
 */
long parse_seconds_duration(char *val)
{
	char *end;
	long t;

	t = strtol(val, &end, 10);

	if (end) {
		switch (*end) {
		case 's':
		case 'S':
			break;
		case 'm':
		case 'M':
			t *= 60;
			break;
		case 'h':
		case 'H':
			t *= 60 * 60;
			break;

		case 'd':
		case 'D':
			t *= 24 * 60 * 60;
			break;
		}
	}

	return t;
}

/*
 * parse_ns_duration - parse duration with ns/us/ms/s converting it to nanoseconds
 */
long parse_ns_duration(char *val)
{
	char *end;
	long t;

	t = strtol(val, &end, 10);

	if (end) {
		if (!strncmp(end, "ns", 2)) {
			return t;
		} else if (!strncmp(end, "us", 2)) {
			t *= 1000;
			return t;
		} else if (!strncmp(end, "ms", 2)) {
			t *= 1000 * 1000;
			return t;
		} else if (!strncmp(end, "s", 1)) {
			t *= 1000 * 1000 * 1000;
			return t;
		}
		return -1;
	}

	return t;
}

/*
 * This is a set of helper functions to use SCHED_DEADLINE.
 */
#ifndef __NR_sched_setattr
# ifdef __x86_64__
#  define __NR_sched_setattr	314
# elif __i386__
#  define __NR_sched_setattr	351
# elif __arm__
#  define __NR_sched_setattr	380
# elif __aarch64__ || __riscv
#  define __NR_sched_setattr	274
# elif __powerpc__
#  define __NR_sched_setattr	355
# elif __s390x__
#  define __NR_sched_setattr	345
# endif
#endif

#define SCHED_DEADLINE		6

static inline int syscall_sched_setattr(pid_t pid, const struct sched_attr *attr,
				unsigned int flags) {
	return syscall(__NR_sched_setattr, pid, attr, flags);
}

int __set_sched_attr(int pid, struct sched_attr *attr)
{
	int flags = 0;
	int retval;

	retval = syscall_sched_setattr(pid, attr, flags);
	if (retval < 0) {
		err_msg(