netdev-pci-speed

#!/bin/bash

set -eu

DEVICE="$1"
if [ ! -d /sys/class/net/$DEVICE ]; then
	echo "No such device $DEVICE"
	exit 2
fi
BUS_ADDR="$(ethtool -i "$DEVICE" | grep bus | awk '{print $2}')"
DEV_SPEED="$(ethtool "$DEVICE" | grep Speed | egrep -o [0-9]+)"
if ! PCI_TYPE="$(dmidecode --type slot | grep -B6 "${BUS_ADDR%.*}" | egrep -m1 -o 'PCI Express [0-9] x[0-9]+')"; then
	echo "$DEVICE is probably built-in"
	exit 1
fi
read _ _ VERSION X <<< "$PCI_TYPE"

if [ "$VERSION" = '1' ]; then
	[ "$X" = 'x1' ] && SLOT_SPEED=250
	[ "$X" = 'x2' ] && SLOT_SPEED=500
	[ "$X" = 'x4' ] && SLOT_SPEED=1000
	[ "$X" = 'x8' ] && SLOT_SPEED=2000
	[ "$X" = 'x16' ] && SLOT_SPEED=4000
elif [ "$VERSION" = '2' ]; then
	[ "$X" = 'x1' ] && SLOT_SPEED=500
	[ "$X" = 'x2' ] && SLOT_SPEED=1000
	[ "$X" = 'x4' ] && SLOT_SPEED=2000
	[ "$X" = 'x8' ] && SLOT_SPEED=4000
	[ "$X" = 'x16' ] && SLOT_SPEED=8000
elif [ "$VERSION" = '3' ]; then
	[ "$X" = 'x1' ] && SLOT_SPEED=984
	[ "$X" = 'x2' ] && SLOT_SPEED=1970
	[ "$X" = 'x4' ] && SLOT_SPEED=3940
	[ "$X" = 'x8' ] && SLOT_SPEED=7880
	[ "$X" = 'x16' ] && SLOT_SPEED=15800
elif [ "$VERSION" = '4' ]; then
	[ "$X" = 'x1' ] && SLOT_SPEED=1969
	[ "$X" = 'x2' ] && SLOT_SPEED=3940
	[ "$X" = 'x4' ] && SLOT_SPEED=7880
	[ "$X" = 'x8' ] && SLOT_SPEED=15750
	[ "$X" = 'x16' ] && SLOT_SPEED=31500
fi
echo "$DEVICE $DEV_SPEED/$((SLOT_SPEED*8))"
exit 0