#!/bin/sh /etc/rc.common
######################################################################
# vim: set ft=bash
# shellcheck disable=2155,3019,3043,3057,3060
######################################################################

START=93

PROG=smp_affinity

log_msg() {
	local irq_name="$1" affinity="$2" irq="$3"
	msg="$(printf "Pinning IRQ($irq) %-24s to CPU ${affinity}\n" "$irq_name")"
	logger -t "$PROG" "$msg"
}

######################################################################
## Takes a comma, space separated, or range list of CPU numbers and
## returns a bitmask of CPUs.
## cpus_to_bitmask "0,1,2,3" -> f
## cpus_to_bitmask "0 1 2 3" -> f
## cpus_to_bitmask "0-3"     -> f
## cpus_to_bitmask "3"       -> 8
#######################################################################

cpus_to_bitmask() {
	local bitmask=0
	# shellcheck disable=2048
	for range in ${*//,/ }; do
		start="${range%-*}"
		end="${range#*-}"
		if [ -z "$end" ]; then
			bitmask="$((bitmask | 1 << start))"
		else
			bitmask="$((bitmask | (2 ** (end - start + 1) - 1) << start))"
		fi
	done
	printf '%x' $bitmask
}

######################################################################
## Takes a bitmask of CPUs and returns a space separated list of
## CPU numbers.
## bitmask_to_cpus f -> 0 1 2 3
######################################################################

bitmask_to_cpus() {
	[ "${1:0:2}" != "0x" ] && set -- "0x$1"
	local bitmask="$(printf '%d' "$1")"

	local cpus=""
	for i in $(seq 0 63); do
		if [ $((bitmask & 1)) -ne 0 ]; then
			cpus="$cpus $i"
		fi
		bitmask=$((bitmask >> 1))
	done
	echo "${cpus# }"
}

######################################################################
## Sets the affinity of the IRQs with the given name to the given CPU.
## 1st argument: IRQ name ("reo2host-destination-ring1") (req)
## 2nd argument: CPU number (req)
######################################################################

set_affinity() {
	local irq_name="$1" affinity="$2" bitmask irq
	awk -v irq_name="$1" '$0 ~ irq_name { print substr($1, 1, length($1)-1); exit }' /proc/interrupts | while read -r irq; do
		$enable_log && log_msg "$irq_name" "$affinity" "$irq"
		bitmask=$(cpus_to_bitmask "$affinity") && echo "$bitmask" > "/proc/irq/$irq/smp_affinity"
	done
}

enable_affinity() {
	# assign 4 rx interrupts to each core
	set_affinity 'reo2host-destination-ring1' 0
	set_affinity 'reo2host-destination-ring2' 1
	set_affinity 'reo2host-destination-ring3' 2
	set_affinity 'reo2host-destination-ring4' 3

	# assign 3 tcl completions to last 3 CPUs
	set_affinity 'wbm2host-tx-completions-ring1' 1
	set_affinity 'wbm2host-tx-completions-ring2' 2
	set_affinity 'wbm2host-tx-completions-ring3' 3

	# assign 3 ppdu mac interrupts to last 3 cores
	set_affinity 'ppdu-end-interrupts-mac1' 1
	set_affinity 'ppdu-end-interrupts-mac2' 2
	set_affinity 'ppdu-end-interrupts-mac3' 3

	# assign 4 lan/wan to core 4
	set_affinity 'edma_txcmpl' 3
	set_affinity 'edma_rxfill' 3
	set_affinity 'edma_rxdesc' 3
	set_affinity 'edma_misc'   3
}

boot() {
	local enable

	config_load smp_affinity

	config_get_bool enable "general" enable 1
	config_get_bool enable_log "general" enable_log 1

	[ "$enable" -eq 1 ] && enable=true || enable=false
	[ "$enable_log" -eq 1 ] && enable_log=true || enable_log=false

	$enable && enable_affinity
}
