#!/bin/sh
# Startup script for cpuspeed
#
# chkconfig: 12345 13 99
# description: Run dynamic CPU speed daemon and/or load appropriate
#              cpu frequency scaling kernel modules and/or governors

# Source function library.
. /etc/rc.d/init.d/functions

prog="cpuspeed"

[ -f /usr/sbin/$prog ] || exit 5

# Get config.
if [ -f /etc/sysconfig/$prog ]; then
  . /etc/sysconfig/$prog
fi

cpu0freqd=/sys/devices/system/cpu/cpu0/cpufreq
cpus='/sys/devices/system/cpu/cpu[0-9]*'
testpat="${cpus}/cpufreq/scaling_driver"
lockfile="/var/lock/subsys/$prog"
xendir="/proc/xen"
logger="/usr/bin/logger -p info -t $prog"
IGNORE_NICE=${IGNORE_NICE:-0}
module_loaded=false

some_file_exist() {
  while [ "$1" ] ; do
    [ -f "$1" ] && return 0
    shift
  done
  return 1
}

governor_is_module() {
  # Check to see if the requested cpufreq governor
  # is provided as a kernel module or not
  module_info=`/sbin/modinfo cpufreq-${governor} > /dev/null 2>&1`
  return $?
}

governor_module_loaded() {
# Check to see if we have a module loaded for
# the current cpufreq governor
  if [ -e ${cpu0freqd}/scaling_governor ]; then
    governor=`cat ${cpu0freqd}/scaling_governor`
  else
    governor="none"
  fi
  if [ "${governor}" != "none" -a `/sbin/lsmod | grep -c -w "cpufreq.${governor}"` -ge 1 ]; then
    return 0
  fi
  return 1
}

adjust_cpufreq() {
  # First arg is a param under $cpu/cpufreq/
  # Second arg is the value you want to set that param to
  for cpu in ${cpus}; do
    echo $2 > $cpu/cpufreq/$1
  done
}

start_cpuspeed() {
  echo -n $"Starting $prog: "
  # cpuspeed daemon thresholds are specified as idle percentages,
  # cpufreq modules as busy percentages, so we need to do some
  # math here for use of unified config...
  # DOWN_THRESHOLD doesn't mean exactly the same thing for
  # cpuspeed as it does for the cpufreq governors, but close
  # enough, and if not specified, we use same defaults as governors.
  if [ -n "$UP_THRESHOLD" ]; then
    let UP_THRESHOLD=100-$UP_THRESHOLD
  else
    UP_THRESHOLD=20
  fi
  if [ -n "$DOWN_THRESHOLD" ]; then
    let DOWN_THRESHOLD=100-$DOWN_THRESHOLD
  else
    DOWN_THRESHOLD=80
  fi
  OPTS="$OPTS -p $UP_THRESHOLD $DOWN_THRESHOLD"
  if [ -n "$MIN_SPEED" ]; then
    OPTS="$OPTS -m $MIN_SPEED"
  fi
  if [ -n "$MAX_SPEED" ]; then
    OPTS="$OPTS -M $MAX_SPEED"
  fi
  if [ "$IGNORE_NICE" -eq 0 ]; then
    OPTS="$OPTS -n"
  fi
  daemon $prog -d $OPTS
  RETVAL=$?
  return $RETVAL
}

stop_cpuspeed() {
  if [ -n "`pidof $prog`" ]; then
    echo -n $"Stopping $prog: "
    killproc $prog -USR1
    killproc $prog -INT
  fi
  if [ -n "`pidof $prog`" ]; then
    killproc $prog
  fi
  RETVAL=$?
  return $RETVAL
}

start() {
  if [ $(id -u) -ne 0 ]; then
    echo -n "Insufficient privileges to start cpuspeed service: "
    failure; echo
    return 4
  fi
  if [ ! -f $lockfile ]; then
    cpu_vendor=$(awk '/vendor_id/{print $3}' /proc/cpuinfo | tail -n 1)
    cpu_family=$(awk '/cpu family/{print $4}' /proc/cpuinfo | tail -n 1)
    cpu_model=$(awk '/model\t/{print $3}' /proc/cpuinfo | tail -n 1)
    cpu_stepping=$(awk '/stepping/{print $3}' /proc/cpuinfo | tail -n 1)

    # http://www.intel.com/Assets/PDF/specupdate/314554.pdf
    #
    # AL30 “A Machine Check Exception (MCE) Occurring during an Enhanced Intel
    # SpeedStep® Technology Ratio Change May Cause Both Processor Cores to Lock
    # Up”, so do not start cpuspeed
    if [ "$cpu_vendor" == GenuineIntel ] && [ "$cpu_family" -eq 15 ] \
        && [ "$cpu_model" -eq 6 ] && [ "$cpu_stepping" -eq 8 ]; then
      $logger "Intel® Xeon® 7100 series CPU's errata will not allow cpuspeed to run."
      $logger "See errata AL30 in http://www.intel.com/Assets/PDF/specupdate/314554.pdf"
      echo -n "Frequency scaling disabled due to CPU bug (see syslog): "
      warning
      echo
      return 6
    fi

    if ! some_file_exist $testpat ; then
      # Attempt to load scaling_driver if not loaded
      # but it is configured
      if [ -n "$DRIVER" ]; then
        /sbin/modprobe "$DRIVER"
      elif [ "$cpu_vendor" == AuthenticAMD ] && [ "$cpu_family" -ge 7 ]; then
        # Try loading powernow-k8 if this is an AMD processor,
        # family 7 or greater (Athlon XP/MP was family 6)
        pk8m=$(/sbin/modinfo powernow-k8 > /dev/null 2>&1)
        if [ "$?" -eq 0 ]; then
          /sbin/modprobe powernow-k8 2> /dev/null
          [ -d ${cpu0freqd} ] || /sbin/modprobe -r powernow-k8 2> /dev/null
        fi
      elif [ -d /proc/acpi ]; then
        # try ACPI
        /sbin/modprobe acpi-cpufreq 2> /dev/null
	# last resort, try speedstep-centrino, if its modular
        if [ ! -d ${cpu0freqd} ]; then
	  /sbin/modprobe -r acpi-cpufreq 2> /dev/null
	  cm=$(/sbin/modinfo speedstep-centrino > /dev/null 2>&1)
          if [ "$?" -eq 0 ]; then
            /sbin/modprobe speedstep-centrino 2> /dev/null
            [ -d ${cpu0freqd} ] || /sbin/modprobe -r speedstep-centrino 2> /dev/null
          fi
        fi
      elif [ $(grep -c "$flags.* est" /proc/cpuinfo) -ge 1 ]; then
        # we might still have a shot with speedstep-centrino...
	cm=$(/sbin/modinfo speedstep-centrino > /dev/null 2>&1)
        if [ "$?" -eq 0 ]; then
          /sbin/modprobe speedstep-centrino 2> /dev/null
          [ -d ${cpu0freqd} ] || /sbin/modprobe -r speedstep-centrino 2> /dev/null
        fi
      else
        # No scaling. Just exit.
        return 6
      fi
    fi

    # If we get this far with no driver, we must have no scaling.
    # We're doomed.
    [ ! -f ${cpu0freqd}/scaling_driver ] && return 6

    # Okay, we have a driver, carry on...
    drv=`cat ${cpu0freqd}/scaling_driver`

    # Figure out default governor to use
    case "$drv" in
      centrino|powernow-k8|acpi-cpufreq|e_powersaver)
        default_governor=ondemand
        ;;
      p4-clockmod)
        # p4-clockmod's latency and lack of actual freq scaling ability
	# makes performance a much better default than ondemand here
        default_governor=performance
        ;;
      *)
        default_governor=userspace
        ;;
    esac

    # https://bugzilla.redhat.com/show_bug.cgi?id=887256
    if [ -d "$xendir" ] && [ "$cpu_vendor" == AuthenticAMD ]; then
      default_governor=performance
    fi

    governor=${GOVERNOR:-${default_governor}}

    # Load governor module, if need be, and validate
    governor_is_module && /sbin/modprobe cpufreq-${governor}
    if [ `grep -c -w ${governor} ${cpu0freqd}/scaling_available_governors` -ge 1 ]; then
      $logger "Enabling ${governor} cpu frequency scaling governor"
    else
      $logger "Invalid governor \"${governor}\" specified, falling back to ${default_governor}"
      governor_is_module && /sbin/modprobe -r cpufreq-${governor}
      governor=${default_governor}
      governor_is_module && /sbin/modprobe cpufreq-${governor}
    fi

    # Set governor
    adjust_cpufreq scaling_governor ${governor}

    # Run cpuspeed daemon for userspace gov, kernel ones otherwise
    if [ "${governor}" == "userspace" ]; then
      if [ ! -d "$xendir" ]; then
        start_cpuspeed
        RETVAL=$?
      else
        $logger "The userspace CPU freq scaling governor does not support Xen"
	RETVAL=6
      fi
    else
      if [ -n "$MIN_SPEED" ]; then
        adjust_cpufreq scaling_min_freq $MIN_SPEED
      else
        adjust_cpufreq scaling_min_freq 0
      fi
      if [ -n "$MAX_SPEED" ]; then
        adjust_cpufreq scaling_max_freq $MAX_SPEED
      else
        adjust_cpufreq scaling_max_freq `cut -d " " -f 1 $cpu/cpufreq/scaling_available_frequencies`
      fi
      if [ -n "$UP_THRESHOLD" -a ${governor} == "ondemand" ]; then
        adjust_cpufreq ondemand/up_threshold $UP_THRESHOLD
      fi
      if [ -n "$DOWN_THRESHOLD" -a ${governor} == "conservative" ]; then
        adjust_cpufreq conservative/down_threshold $DOWN_THRESHOLD
      fi
      if [ "$IGNORE_NICE" -eq 1 -a ${governor} == "ondemand" -o ${governor} == "conservative" ]; then
        adjust_cpufreq ${governor}/ignore_nice_load $IGNORE_NICE
      fi
      echo -n "Enabling ${governor} cpu frequency scaling: "
      success
      RETVAL=0
    fi
    echo
    # Technically, not quite right in non-cpuspeed daemon
    # cases, but close enough to indicate that we're
    # doing some sort of cpu frequency scaling.
    [ $RETVAL = 0 ] && touch $lockfile
  else
    # cpuspeed is already started
    RETVAL=1
  fi
  return $RETVAL
}

stop() {
  if [ $(id -u) -ne 0 ]; then
    echo -n "Insufficient privileges to stop cpuspeed service: "
    failure; echo
    return 4
  fi
  [ ! -f ${cpu0freqd}/scaling_driver ] && return 0
  drv=`cat ${cpu0freqd}/scaling_driver`
  governor_module_loaded && module_loaded=true

  if [ "${governor}" != "userspace" ]; then
    echo -n "Disabling ${governor} cpu frequency scaling: "
    $logger "Disabling ${governor} cpu frequency scaling governor"
    for cpu in ${cpus}; do
      echo userspace > $cpu/cpufreq/scaling_governor
      cat $cpu/cpufreq/cpuinfo_max_freq > $cpu/cpufreq/scaling_setspeed
    done
    if [ $module_loaded == true ]; then
      /sbin/modprobe -r cpufreq-${governor}
    fi
    success
    RETVAL=0
  else
    stop_cpuspeed
    RETVAL=$?
  fi
  echo
  [ -n "$DRIVER" ] && /sbin/modprobe -r $DRIVER
  [ $RETVAL = 0 ] && RETVAL=$?
  [ $RETVAL = 0 ] && rm -f $lockfile
  return $RETVAL
}

case "$1" in
  start)
    start
    ;;

  stop)
    stop
    ;;

  status)
    governor_module_loaded && module_loaded=true
    if [ $module_loaded == true -o ${governor} == "performance" ]; then
      echo "Frequency scaling enabled using ${governor} governor"
    else
      status $prog
      RETVAL=$?
    fi
    ;;

  restart|reload|force-reload)
    stop
    start
    ;;

  condrestart|try-restart)
    governor_module_loaded && module_loaded=true
    if [ $module_loaded == true -o -n "`pidof $prog`" -o ${governor} == "performance" ]; then
      stop
      start
    fi
    ;;

  *)
    echo $"Usage: $0 {start|stop|restart|condrestart|status}"
    exit 2
    ;;
esac

exit $RETVAL