#!/bin/bash
# SPDX-License-Identifier: BSD-3-Clause
# Copyright 2018-2019 NXP

# This script should be executed as root user.
function validate_root_user() {
	if [ "$EUID" -ne 0 ]
	then
		echo "Not a root user!."
		echo "This script should be run as 'root' (not sudo)."
		return 1
	fi
	return 0
}

validate_root_user
if [ $? -ne 0 ]
then
	[ "$0" == "-bash" ] && return 1 || exit 1
fi

# Enable the 'performance' mode for the CPU power governors
# This currently supports 16 cores and breaks out after first non-available
# core.
for i in `seq 0 15`
do
	if [ -e "/sys/devices/system/cpu/cpu${i}/cpufreq/scaling_governor" ]
	then
		echo 'performance' > /sys/devices/system/cpu/cpu${i}/cpufreq/scaling_governor
	else
		echo "Setting performance mode on ${i} cores only."
		break
	fi
done

echo "Check that all I/O cores required has 'performance' mode enabled"
for i in `seq 0 15`
do
	if [ -e "/sys/devices/system/cpu/cpu${i}/cpufreq/scaling_governor" ]
	then
		echo -n "CPU governor mode $i:"
		cat /sys/devices/system/cpu/cpu${i}/cpufreq/scaling_governor
	else
		break
	fi
done

# Disable some watchdogs so as not to complain in case RT priority process
# of DPDK application hog the CPU. Ignore errors like non-existent file.
(echo 0 > /proc/sys/kernel/hung_task_timeout_secs) 2> /dev/null
(echo 0 > /proc/sys/kernel/nmi_watchdog) 2> /dev/null
(echo 0 > /proc/sys/kernel/hung_task_check_count) 2> /dev/null
(echo 0 > /proc/sys/kernel/hung_task_warnings) 2> /dev/null
(echo 0 > /proc/sys/kernel/soft_watchdog) 2> /dev/null

# Finally, reduce timeslice for non-RT processes. This directly impacts the
# Core 0 (non-isolated cores). Once this is set, a RT application which
# doesn't yield the CPU would stall it.

if [ -e "/proc/sys/kernel/sched_rt_runtime_us" ]
then
	echo -1 > /proc/sys/kernel/sched_rt_runtime_us
	echo "WARN: Hereafter, don't execute RT tasks on Core 0"
else
	echo "Unable to reduce non-RT timeslice; Performance will be reduced"
fi

# Enable the DPDK Performance mode; This script should be 'source'd rather
# than directly executed for this to take effect.
if [ "$0" != "-bash" ]
then
	# this script was probably executed using "./enable_performance_mode"
	echo "This script should be sourced and not directly executed!"
	echo "Please run:"
	echo "export NXP_CHRT_PERF_MODE=1"
else
	export NXP_CHRT_PERF_MODE=1
fi