Nvidia

#!/usr/bin/env bash

DRY_RUN=0
function printHelp {
  echo "Utility to run games and applications in separate X on discrete Nvidia graphic card"
  echo "Usage: "
  echo "nvidia-xrun [<options>] [<app>]"
  echo "Options: "
  echo "  -d    Dry run - prints the final command but does not execute it"
}

function execute {
  if [[ ${DRY_RUN} -eq 1 ]]
    then
    echo ">>Dry run. Command: $*"
  else
    eval $*
  fi
}

function turn_off_gpu {
  if [[ "$REMOVE_DEVICE" == '1' ]]; then
    echo 'Removing Nvidia bus from the kernel'
    execute "sudo tee /sys/bus/pci/devices/${DEVICE_BUS_ID}/remove <<<1"
    execute "sudo tee /sys/bus/pci/devices/0000:01:00.1/remove <<<1"
  else
    echo 'Enabling powersave for the graphic card'
    execute "sudo tee /sys/bus/pci/devices/${DEVICE_BUS_ID}/power/control <<<auto"
  fi

  echo 'Enabling powersave for the PCIe controller'
  execute "sudo tee /sys/bus/pci/devices/${CONTROLLER_BUS_ID}/power/control <<<auto"
}

function turn_on_gpu {
  echo 'Turning the PCIe controller on to allow card rescan'
  execute "sudo tee /sys/bus/pci/devices/${CONTROLLER_BUS_ID}/power/control <<<on"

  echo 'Waiting 1 second'
  execute "sleep 1"

  if [[ ! -d /sys/bus/pci/devices/${DEVICE_BUS_ID} ]]; then
    echo 'Rescanning PCI devices'
    execute "sudo tee /sys/bus/pci/rescan <<<1"
    echo "Waiting ${BUS_RESCAN_WAIT_SEC} second for rescan"
    execute "sleep ${BUS_RESCAN_WAIT_SEC}"
  fi

  echo 'Turning the card on'
  execute "sudo tee /sys/bus/pci/devices/${DEVICE_BUS_ID}/power/control <<<on"
}

function load_modules {
  for module in "${MODULES_LOAD[@]}"
  do
    echo "Loading module ${module}"
    execute "sudo modprobe ${module}"
  done
}

function unload_modules {
  for module in "${MODULES_UNLOAD[@]}"
  do
    echo "Unloading module ${module}"
    execute "sudo modprobe -r ${module}"
  done
}

if [[ "$1" == "-d" ]]
  then
    DRY_RUN=1
    shift 1
fi

# load config file
. /etc/default/nvidia-xrun

# this is used by the systemd service to turn off the gpu at boot
if [[ "$TURN_OFF_GPU_ONLY" == '1' ]]; then
  turn_off_gpu && exit 0
fi

if [[ $EUID -eq 0 ]]; then
   echo "This script must not be run as root unless TURN_OFF_GPU_ONLY=1 is set" >&2
   exit 1
fi

# calculate current VT
LVT=`fgconsole`

# calculate first usable display
XNUM="-1"
SOCK="something"
while [[ ! -z "$SOCK" ]]
do
  XNUM=$(( $XNUM + 1 ))
  SOCK=$(ls -A -1 /tmp/.X11-unix | grep "X$XNUM" )
done

NEWDISP=":$XNUM"

if [[ ! -z "$*" ]] # generate exec line if arguments are given
then
  # test if executable exists in path
  if [[ -x "$(which $1 2> /dev/null)" ]]
  then
    # generate exec line
    EXECL="$(which $1)"
  # test if executable exists on disk
  elif [[ -e "$(realpath "$1")" ]]
  then
    # generate exec line
    EXECL="$(realpath "$1")"
  else
    echo "$1: No such executable!"
    exit 1
  fi
  shift 1
  EXECL="$EXECL $*"
else # prepare to start new X sessions if no arguments passed
  EXECL=""
fi

EXECL="/etc/X11/xinit/nvidia-xinitrc \"$EXECL\""

COMMAND="xinit $EXECL -- $NEWDISP vt$LVT -nolisten tcp -br -config nvidia-xorg.conf -configdir nvidia-xorg.conf.d"

# --------- TURNING ON GPU -----------
if [[ "$ENABLE_PM" == '1' ]]; then
  turn_on_gpu
fi

# ---------- LOADING MODULES ----------
load_modules

# ---------- EXECUTING COMMAND --------
execute ${COMMAND}

# ---------- UNLOADING MODULES --------
unload_modules

# --------- TURNING OFF GPU ----------
if [[ "$ENABLE_PM" == '1' ]]; then
  turn_off_gpu
fi