#!/bin/sh
#
# dpdk-init: startup script to initialize a dpdk runtime environment
#
# Copyright 2015-2016 Canonical Ltd.
# Autor: Stefan Bader <stefan.bader@canonical.com>
# Autor: Christian Ehrhardt <christian.ehrhardt@canonical.com>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License version 3,
#    as published by the Free Software Foundation.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
set -e

DPDK_BIND="/sbin/dpdk_nic_bind"
DPDK_INTERF="/etc/dpdk/interfaces"


# pagesize supports [G|g]/[M|m]/[K|k]
get_kbytes() {
    local unit
    local num
    unit=$(echo "${1}" | sed 's/[0-9]*//g')
    num=$(echo "${1}" | sed 's/[^0-9]*//g')
    case ${unit} in
    *g | *G)
        echo $((num*1024*1024))
        ;;
    *m | *M)
        echo $((num*1024))
        ;;
    *k | *K)
        echo $((num))
        ;;
    *)
        echo $((num/1024))
        ;;
    esac
}

get_default_hpgsz() {
    default_hpgsz=$(grep "Hugepagesize:" /proc/meminfo \
        | sed 's/^Hugepagesize:\s*//g' | sed 's/\s*kB$//g')
    echo "${default_hpgsz}"
}

get_hugetlbfs_mountpoint() {
    local requested_hpgsz
    local mp_hpgsz
    requested_hpgsz=$(get_kbytes "${1}")

    grep hugetlbfs /proc/mounts | while read \
        mntfrom mntpoint mntfstype mntopt mntdump mntfsck; do

        # check if the current muntpoint is of the requested huge page size
        case ${mntopt} in
        *pagesize=*)
            mp_hpgsz=$(echo "${mntopt}" | sed 's/.*pagesize=//g' | sed 's/,.*//g')
            mp_hpgsz=$(get_kbytes "${mp_hpgsz}")
            ;;
        *)
            mp_hpgsz=$(get_default_hpgsz)
            ;;
        esac
        if [ "${requested_hpgsz}" -eq "${mp_hpgsz}" ]; then
            echo "${mntpoint}"
            return
        fi
    done
}

_mount_hugetlbfs() {
    local MNT="/dev/hugepages"
    local MNTOPTS=""
    local requested_hpgsz
    local default_hpgsz
    requested_hpgsz=$(get_kbytes "${1}")
    default_hpgsz=$(get_default_hpgsz)

    # kernel might not support the requested size
    if [ ! -d "/sys/kernel/mm/hugepages/hugepages-${requested_hpgsz}kB" ]; then
        echo "WARNING: requested page size of ${requested_hpgsz}kB " \
             "not supported by the kernel"
        return 0
    fi

    # special case if this is not the default huge page size
    if [ "${requested_hpgsz}" -ne "${default_hpgsz}" ]; then
        MNT="${MNT}-${requested_hpgsz}"
        MNTOPTS="pagesize=${requested_hpgsz}K"
    fi

    if [ ! -e "${MNT}" ]; then
        mkdir "${MNT}"
        if [ $? -ne 0 ]; then
            echo "Could not create directory ${MNT}!" >&2
            return 1
        fi
    fi
    mount -thugetlbfs hugetlbfs "${MNT}" -o "${MNTOPTS}"
    return $?
}

#
# The DPDK library will use the first mounted instance it finds for a given
# page size. so if there is already one for a given size there is no need to
# create another for the same huge page size.
#
mount_hugetlbfs() {
    if [ ! -r /etc/dpdk/dpdk.conf ]; then
        return 1
    fi
    . /etc/dpdk/dpdk.conf

    # if a page size is requested, there has to be a mountpoint for that size
    if [ -n "${NR_2M_PAGES}" -a -z "$(get_hugetlbfs_mountpoint '2M')" ]; then
        _mount_hugetlbfs 2M
    fi
    if [ -n "${NR_1G_PAGES}" -a -z "$(get_hugetlbfs_mountpoint '1G')" ]; then
        _mount_hugetlbfs 1G
    fi
}

_setup_hugepages() {
    MMDIR="/sys/kernel/mm/hugepages/${1}"
    PAGES=${2}

    if [ "$PAGES" != "" ]; then
        if [ "$PAGES" -gt 0 ]; then
            if [ -d "$MMDIR" -a -w "$MMDIR/nr_hugepages" ]; then
                # increases the chance to allocate enough huge pages
                # configurable, since it comes at a perf penality
                if [ "$DROPCACHE_BEFORE_HP_ALLOC" = "1" ]; then
                    echo 3 > /proc/sys/vm/drop_caches
                fi

                echo "$PAGES" > "$MMDIR/nr_hugepages"

                GOTPAGES=$(cat "$MMDIR/nr_hugepages")
                if [ "$GOTPAGES" -lt "$PAGES" ]; then
                    echo "WARNING: could not allocate $PAGES at " \
                         "$MMDIR/nr_hugepages (only got $GOTPAGES)."
                fi
            else
                echo "WARNING: $MMDIR/nr_hugepages not found/writable"
            fi
        fi
    fi
}

#
# Reserve a certain amount of hugepages (defined in /etc/dpdk.conf)
#
setup_hugepages() {
    if [ ! -r /etc/dpdk/dpdk.conf ]; then
        return 1
    fi
    . /etc/dpdk/dpdk.conf

    _setup_hugepages "hugepages-2048kB" "$NR_2M_PAGES"
    _setup_hugepages "hugepages-1048576kB" "$NR_1G_PAGES"

    # dpdk uses 2*#hugepages mappings, increase for huge systems LP #1507921
    if [ -d /sys/kernel/mm/hugepages ]; then
        max_map_count=$(awk -v pad=65530 '{tot+=$1}END{print tot*2+pad}' \
            /sys/kernel/mm/hugepages/hugepages-*/nr_hugepages)
        sysctl -q vm.max_map_count="${max_map_count:-65530}"
    fi

    return 0
}

#
# Allow NICs to be automatically bound to DPDK compatible drivers on boot.
#
bind_interfaces() {
    if [ ! -r "$DPDK_INTERF" ]; then
        return 0
    fi
    grep -v '^[ \t]*#' "$DPDK_INTERF" | while read BUS ID MOD; do
        if [ "$BUS" = "" -o "$ID" = "" -o "$MOD" = "" ]; then
            echo "WARNING: incomplete spec in $DPDK_INTERF" \
                " - BUS '$BUS' ID '$ID' MOD '$MOD'"
            continue
        fi
        if [ "$BUS" != "pci" ]; then
            echo "WARNING: incompatible bus '$BUS' in $DPDK_INTERF"
            continue
        fi

        SYSFSPATH="/sys/bus/$BUS/devices/$ID"
        if [ ! -e "$SYSFSPATH" ]; then
            echo "WARNING: invalid pci ID '$ID' in $DPDK_INTERF" \
                " - '$SYSFSPATH' does not exist"
            continue
        fi
        if [ -L "$SYSFSPATH/driver" ]; then
            CUR=$(readlink "$SYSFSPATH/driver")
            CUR=$(basename "$CUR")
        else
            # device existing, but currently unregistered
            CUR=""
        fi
        if [ "$MOD" != "$CUR" ]; then
            modprobe -q "$MOD" || true
            # cloud img have no linux-image-extra initially (uip_pci_generic)
            # so check if the module is available (loadable/built in)
            if [ -e "/sys/bus/pci/drivers/${MOD}" ]; then
                echo "Reassigning pci:$ID to $MOD"
                $DPDK_BIND -b "$MOD" "$ID"
            else
                echo "Warning: failed assigning pci:$ID," \
                     " module $MOD not available"
            fi
        else
            echo "pci:$ID already assigned to $MOD"
        fi
    done
}



case "$1" in
start)
    mount_hugetlbfs
    setup_hugepages
    bind_interfaces
    ;;
stop)
    ;;
reload|force-reload)
    setup_hugepages
    bind_interfaces
    ;;
status)
    $DPDK_BIND --status
    ;;
*)
    echo "Usage: $0 {start|stop|reload|force-reload|status}"
    exit 1
    ;;
esac

