#!/bin/bash -e
# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
# Copyright (C) 2017 Netronome Systems, Inc.

usage() {
    echo "Usage: $0 NETDEV"
    echo "          Optional env vars: IRQ_NAME_FMT"
    exit 1
}

[ $# -ne 1 ] && usage

[ "a$IRQ_NAME_FMT" == a ] && IRQ_NAME_FMT=$1-rxtx

DEV=$1
if ! [ -e /sys/bus/pci/devices/$DEV ]; then
    DEV=$(ethtool -i $1 | grep bus | awk '{print $2}')
    N_TX=$(ls /sys/class/net/$1/queues/ | grep tx | wc -l)
    N_CPUS=$(ls /sys/bus/cpu/devices/ | wc -l)
fi

[ "a$DEV" == a ] && usage

NODE=$(cat /sys/bus/pci/devices/$DEV/numa_node)

# A bug fix in v5.10 correctly sets the NUMA node to unknown (-1) on systems
# with no NUMA configuration. Correct for this by assuming node 0 to keep
# same behavior on kernels with and without the bug fix.
if [[ "$NODE" == "-1" ]]; then
    NODE=0
fi

CPUL=$(cat /sys/bus/node/devices/node${NODE}/cpulist | tr ',' ' ')

N_NODES=$(ls /sys/bus/node/devices/ | wc -l)

for c in $CPUL; do
    # Convert "n-m" into "n n+1 n+2 ... m"
    [[ "$c" =~ '-' ]] && c=$(seq $(echo $c | tr '-' ' '))

    CPUS=(${CPUS[@]} $c)
done

echo Device $DEV is on node $NODE with cpus ${CPUS[@]}

IRQBAL=$(ps aux | grep irqbalance | wc -l)

[ $IRQBAL -ne 1 ] && echo Killing irqbalance && killall irqbalance

IRQS=$(ls /sys/bus/pci/devices/$DEV/msi_irqs/)


IRQS=($IRQS)

node_mask=$((~(~0 << N_NODES)))
node_shf=$((N_NODES - 1))
cpu_shf=$((N_TX << node_shf))

p_mask=0
id=0
for i in $(seq 0 $((${#IRQS[@]} - 1)))
do
    ! [ -e /proc/irq/${IRQS[i]} ] && continue

    name=$(basename /proc/irq/${IRQS[i]}/$IRQ_NAME_FMT*)
    ls /proc/irq/${IRQS[i]}/$IRQ_NAME_FMT* >>/dev/null 2>/dev/null || continue

    cpu=${CPUS[id % ${#CPUS[@]}]}

    m=0
    m_mask=node_mask
    if [ $N_TX -gt $((id + ${#CPUS[@]})) ]; then
	# Only take one CPU if there will be more rings on this CPU
	m_mask=1
    fi
    # Calc the masks we should cover
    for j in `seq 0 $cpu_shf $((N_CPUS - 1))`; do
	m=$((m << cpu_shf | (m_mask << ((cpu >> node_shf) << node_shf))))
	m=$((m & ~p_mask))
    done
    xps_mask=$(printf "%x" $((m % (1 << N_CPUS))))
    # Insert comma between low and hi 32 bits, if xps_mask is long enough
    xps_mask=`echo $xps_mask | sed 's/\(.\)\(.\{8\}$\)/\1,\2/'`
    p_mask=$((p_mask | m))

    echo $cpu > /proc/irq/${IRQS[i]}/smp_affinity_list
    irq_state="irq: $(cat /proc/irq/${IRQS[i]}/smp_affinity)"

    xps_state='xps: ---'
    xps_file=/sys/class/net/$1/queues/tx-$id/xps_cpus
    if [ -e $xps_file ]; then
	echo $xps_mask > $xps_file
	xps_state="xps: $(cat $xps_file)"
    fi

    echo -e "IRQ ${IRQS[i]} to CPU $cpu     ($irq_state $xps_state)"
    ((++id))
done