#
# Copyright IBM Corp. 2023
#
# s390-tools is free software; you can redistribute it and/or modify
# it under the terms of the MIT license. See LICENSE for details.
#
# zdev-from-dasd_mod.dasd
#   Shell library, which can be sourced by other POSIX compatible shell scripts.
#   Provide helper function parsing its stdin based on the syntax of kernel
#   device driver parameter dasd_mod.dasd= and invoking chzdev to produce
#   corresponding persistent device configurations. The helper function
#   takes one argument, which is either "globals" or "ranges". For a
#   complete configuration, call the function twice, first with "globals"
#   and then with "ranges".
#
# shellcheck shell=sh

# It would be possible to pass the collected rd.dasd options via
# modprobe.d. However, it is still required to parse the options to handle
# cio_ignore. That in turn ensures devices get sensed. Sensing is in turn
# required for automatically loading the device drivers via modalias and
# for the dasd device driver to find devices it can probe (set online). So
# go all the way and parse the rd.dasd options. For device bus-IDs, use
# chzdev, which not only handles cio_ignore transparently, but also
# generates persistent configuration that can be transferred from initrd to
# another root files system such as in a distro installer environment.

zdev_dasd_base_args="--no-settle --yes --no-root-update --no-module-load --quiet"

zdev_parse_dasd_list() {
    sed 's/,/\n/g' | while read -r _zdev_dasditem; do
        unset _zdev_dasd_range _zdev_dasd_features _zdev_dasd_attrs
        case $_zdev_dasditem in
            autodetect|probeonly|nopav|nofcx)
                [ "$1" = "globals" ] || continue
                # Autodetect can of course only enable devices that are not
                # in the cio_ignore list.
                # Intentionally do not dynamically configure now, but only
                # generate a modprobe.d file, which configures the device
                # later during kernel module load.
                echo "rd.dasd ...,${_zdev_dasditem},... :"
                # shellcheck disable=SC2086
                chzdev dasd --type "${_zdev_dasditem}=1" --persistent \
                       $zdev_dasd_base_args --force
                ;;
            "") continue ;; # empty range
            *)  # currently no support for a device-spec "ipldev", only devbusid
                [ "$1" = "ranges" ] || continue
                SAVED_IFS="$IFS"
                IFS='('
                read -r _zdev_dasd_range _zdev_dasd_features <<EOF
$_zdev_dasditem
EOF
                IFS="$SAVED_IFS"
                if [ "${_zdev_dasd_features%%*)}" != "" ]; then
                    warn "rd.dasd: Missing closing parenthesis at features of DASD range $_zdev_dasd_range: ($_zdev_dasd_features"
                fi
                if [ -n "$_zdev_dasd_features" ]; then
                    _zdev_dasd_features="${_zdev_dasd_features%)}"
                    _zdev_dasd_features=$(echo "$_zdev_dasd_features" | sed 's/:/\n/g')
                    while read -r _zdev_dasd_feature; do
                        case $_zdev_dasd_feature in
                            ro) _zdev_dasd_attrs="$_zdev_dasd_attrs readonly=1" ;;
                            diag) _zdev_dasd_attrs="$_zdev_dasd_attrs use_diag=1" ;;
                            raw) _zdev_dasd_attrs="$_zdev_dasd_attrs raw_track_access=1" ;;
                            erplog|failfast) _zdev_dasd_attrs="$_zdev_dasd_attrs ${_zdev_dasd_feature}=1" ;;
                            *)
                                warn "rd.dasd: Unknown DASD feature for device range $_zdev_dasd_range: $_zdev_dasd_feature"
                                ;;
                        esac
                    done <<EOF
$_zdev_dasd_features
EOF
                fi

                # Without dynamic (active) config zdev cannot infer
                # the actual dasd type (eckd, fba). Add logic to generate the
                # udev rules based on the availability of modalias entry.

                echo "rd.dasd ...,${_zdev_dasditem},... :"

                # free the dev-ids from blacklist to analyse the modalias
                echo "free $_zdev_dasd_range" > /proc/cio_ignore
                echo 1 > /proc/cio_settle

                # Now, Configure both DASD types. While doing so, ensure that
                # module loading is suppressed and that the --force option
                # is not used with chzdev.
                # As a result:
                #   - For non-existent devices, udev rules are generated for
                #     both DASD types.
                #   - For existing devices identified as generic-ccw, chzdev
                #     skips generating udev rules.

                for dasd_type in dasd-eckd dasd-fba; do
                    chzdev "$dasd_type" --enable --persistent "$_zdev_dasd_range" \
                           $_zdev_dasd_attrs $zdev_dasd_base_args 2>/dev/null \
                           | sed -e 's/^/Non-existent /g'
                done

                # For the existing devices, configure the right dasd-type based
                # on modalias
                lszdev "$_zdev_dasd_range" --active --no-headings --columns \
                       ID,attr:modalias | \
                while read -r dev_id modalias_val; do
                    case "$modalias_val" in
                        # ECKD device types
                        *3390*|*3380*|*9345*)
                            chzdev dasd-eckd --enable --persistent "$dev_id" \
                            $_zdev_dasd_attrs $zdev_dasd_base_args --force
                            ;;
                        # FBA device types
                        *3370*|*9336*)
                            chzdev dasd-fba --enable --persistent "$dev_id" \
                            $_zdev_dasd_attrs $zdev_dasd_base_args --force
                            ;;
                    esac
                done
                ;;
        esac
    done # input redir w/ process substitution causes syntax error in dracut env
}