Re: [PATCH net-next 0/9] DSA changes for multiple CPU ports (part 4)

[Vladimir Oltean]

On Fri, Sep 02, 2022 at 08:44:37PM +0200, Christian Marangi wrote:
> Hi,
> I would love to test this but for me it's a bit problematic to use a
> net-next kernel. I wonder if it's possible to backport the 4 part to
> older kernel or other prereq are needed. (I know backporting the 4 part
> will be crazy but it's something that has to be done anyway to actually
> use this on OpenWrt where we currently use 5.10 and 5.15)
> 
> Would be good to know if the 4 part require other changes to dsa core to
> make a LAG implementation working. (talking for 5.15 since backporting
> this to 5.10 is a nono...)

For testing, iproute2 patch should be coming up soon here:
https://lore.kernel.org/netdev/20220904190025.813574-1-vladimir.oltean@xxxxxxx/

I tried to backport something on the current linux-stable/linux-5.15.y.
https://github.com/vladimiroltean/linux/tree/dsa-5.15.y

Consider it a work in progress. It compiles and boots on NXP LS1028A,
but I can't guarantee anything beyond that. Furthermore, I've only
backported the merged patches, not the patch set discussed here proper.

I think it would be nice if we had a collaborative tree with DSA
backports for 5.15, because here I just tried to backport the DSA core
rather than all driver changes (since I would be unable to test those).

For transparency, here is the commit list I used to produce the backport (top-most is most recent):

$ cat stable-commits.txt
5dc760d12082 net: dsa: use dsa_tree_for_each_cpu_port in dsa_tree_{setup,teardown}_master
f41ec1fd1c20 net: dsa: all DSA masters must be down when changing the tagging protocol
7136097e1199 net: dsa: only bring down user ports assigned to a given DSA master
4f03dcc6b9a0 net: dsa: existing DSA masters cannot join upper interfaces
920a33cd7231 net: bridge: move DSA master bridging restriction to DSA
0498277ee17b net: dsa: don't stop at NOTIFY_OK when calling ds->ops->port_prechangeupper
4c3f80d22b2e net: dsa: walk through all changeupper notifier functions
be6ff9665d64 net: dsa: don't emit targeted cross-chip notifiers for MTU change
4715029fa7e9 net: dsa: drop dsa_slave_priv from dsa_slave_change_mtu
cf1c39d3b3a5 net: dsa: avoid one dsa_to_port() in dsa_slave_change_mtu
b2033a05a719 net: dsa: use dsa_tree_for_each_user_port in dsa_slave_change_mtu
726816a129cb net: dsa: make cross-chip notifiers more efficient for host events
8e9e678e4758 net: dsa: move reset of VLAN filtering to dsa_port_switchdev_unsync_attrs
762c2998c962 Revert "net: dsa: setup master before ports"
8e6598a7b0fa net: dsa: Pass VLAN MSTI migration notifications to driver
332afc4c8c0d net: dsa: Validate hardware support for MST
f54fd0e16306 net: bridge: mst: Add helper to query a port's MST state
48d57b2e5f43 net: bridge: mst: Add helper to check if MST is enabled
cceac97afa09 net: bridge: mst: Add helper to map an MSTI to a VID set
7ae9147f4312 net: bridge: mst: Notify switchdev drivers of MST state changes
6284c723d9b9 net: bridge: mst: Notify switchdev drivers of VLAN MSTI migrations
87c167bb94ee net: bridge: mst: Notify switchdev drivers of MST mode changes
122c29486e1f net: bridge: mst: Support setting and reporting MST port states
8c678d60562f net: bridge: mst: Allow changing a VLAN's MSTI
ec7328b59176 net: bridge: mst: Multiple Spanning Tree (MST) mode
0832cd9f1f02 net: dsa: warn if port lists aren't empty in dsa_port_teardown
afb3cc1a397d net: dsa: unlock the rtnl_mutex when dsa_master_setup() fails
7569459a52c9 net: dsa: manage flooding on the CPU ports
499aa9e1b332 net: dsa: install the primary unicast MAC address as standalone port host FDB
5e8a1e03aa4d net: dsa: install secondary unicast and multicast addresses as host FDB/MDB
68d6d71eafd1 net: dsa: rename the host FDB and MDB methods to contain the "bridge" namespace
35aae5ab9121 net: dsa: remove workarounds for changing master promisc/allmulti only while up
06b9cce42634 net: dsa: pass extack to .port_bridge_join driver methods
c26933639b54 net: dsa: request drivers to perform FDB isolation
b6362bdf750b net: dsa: tag_8021q: rename dsa_8021q_bridge_tx_fwd_offload_vid
04b67e18ce5b net: dsa: tag_8021q: merge RX and TX VLANs
08f44db3abe6 net: dsa: felix: delete workarounds present due to SVL tag_8021q bridging
d27656d02d85 docs: net: dsa: sja1105: document limitations of tc-flower rule VLAN awareness
d7f9787a763f net: dsa: tag_8021q: add support for imprecise RX based on the VBID
91495f21fcec net: dsa: tag_8021q: replace the SVL bridging with VLAN-unaware IVL bridging
961d8b699070 net: dsa: felix: support FDB entries on offloaded LAG interfaces
e212fa7c5418 net: dsa: support FDB events on offloaded LAG interfaces
93c798230af5 net: dsa: call SWITCHDEV_FDB_OFFLOADED for the orig_dev
e35f12e993d4 net: dsa: remove "ds" and "port" from struct dsa_switchdev_event_work
ec638740fce9 net: switchdev: remove lag_mod_cb from switchdev_handle_fdb_event_to_device
dedd6a009f41 net: dsa: create a dsa_lag structure
b99dbdf00bc1 net: dsa: mv88e6xxx: use dsa_switch_for_each_port in mv88e6xxx_lag_sync_masks
3d4a0a2a46ab net: dsa: make LAG IDs one-based
066ce9779c7a net: dsa: qca8k: rename references to "lag" as "lag_dev"
e23eba722861 net: dsa: mv88e6xxx: rename references to "lag" as "lag_dev"
46a76724e4c9 net: dsa: rename references to "lag" as "lag_dev"
b9e8b58fd2cb net: dsa: Include BR_PORT_LOCKED in the list of synced brport flags
a21d9a670d81 net: bridge: Add support for bridge port in locked mode
acd8df5880d7 net: switchdev: avoid infinite recursion from LAG to bridge with port object handler
342b6419193c net: dsa: fix panic when removing unoffloaded port from bridge
8940e6b669ca net: dsa: avoid call to __dev_set_promiscuity() while rtnl_mutex isn't held
ba43b547515e net: lan966x: remove guards against !BRIDGE_VLAN_INFO_BRENTRY
e42bd4ed09aa net: mscc: ocelot: keep traps in a list
85ea0daabe5a net: mscc: ocelot: avoid overlap in VCAP IS2 between PTP and MRP traps
b9bace6e534d net: mscc: ocelot: use a single VCAP filter for all MRP traps
36fac35b2907 net: mscc: ocelot: delete OCELOT_MRP_CPUQ
c518afec2883 net: mscc: ocelot: consolidate cookie allocation for private VCAP rules
e3c02b7c655c net: mscc: ocelot: use a consistent cookie for MRP traps
164f861bd40c net: dsa: offload bridge port VLANs on foreign interfaces
134ef2388e7f net: dsa: add explicit support for host bridge VLANs
c4076cdd21f8 net: switchdev: introduce switchdev_handle_port_obj_{add,del} for foreign interfaces
7b465f4cf39e net: switchdev: rename switchdev_lower_dev_find to switchdev_lower_dev_find_rcu
b28d580e2939 net: bridge: switchdev: replay all VLAN groups
263029ae3172 net: bridge: make nbp_switchdev_unsync_objs() follow reverse order of sync()
8d23a54f5bee net: bridge: switchdev: differentiate new VLANs from changed ones
27c5f74c7ba7 net: bridge: vlan: notify switchdev only when something changed
cab2cd770051 net: bridge: vlan: make __vlan_add_flags react only to PVID and UNTAGGED
3116ad0696dd net: bridge: vlan: don't notify to switchdev master VLANs without BRENTRY flag
b2bc58d41fde net: bridge: vlan: check early for lack of BRENTRY flag in br_vlan_add_existing
ef5764057540 net: mscc: ocelot: fix use-after-free in ocelot_vlan_del()
5454f5c28eca net: bridge: vlan: check for errors from __vlan_del in __vlan_flush
867b1db874c9 net: lan966x: Fix when CONFIG_IPV6 is not set
1da52b0e4724 net: lan966x: Fix when CONFIG_PTP_1588_CLOCK is compiled as module
59085208e4a2 net: mscc: ocelot: fix all IP traffic getting trapped to CPU with PTP over IP
47aeea0d57e8 net: lan966x: Implement the callback SWITCHDEV_ATTR_ID_BRIDGE_MC_DISABLED
cddbec19466a net: dsa: qca8k: add tracking state of master port
e83d56537859 net: dsa: replay master state events in dsa_tree_{setup,teardown}_master
295ab96f478d net: dsa: provide switch operations for tracking the master state
a1ff94c2973c net: dsa: stop updating master MTU from master.c
77eecf25bd9d net: lan966x: Update extraction/injection for timestamping
735fec995b21 net: lan966x: Implement SIOCSHWTSTAMP and SIOCGHWTSTAMP
d096459494a8 net: lan966x: Add support for ptp clocks
108dc8741c20 net: dsa: Avoid cross-chip syncing of VLAN filtering
381a730182f1 net: dsa: Move VLAN filtering syncing out of dsa_switch_bridge_leave
5cad43a52ee3 net: dsa: felix: add port fast age support
1b26d364e4e9 net: dsa: warn about dsa_port and dsa_switch bit fields being non atomic
63cfc65753d6 net: dsa: don't enumerate dsa_switch and dsa_port bit fields using commas
11fd667dac31 net: dsa: setup master before ports
1e3f407f3cac net: dsa: first set up shared ports, then non-shared ports
c146f9bc195a net: dsa: hold rtnl_mutex when calling dsa_master_{setup,teardown}
a68dc7b938fb net: dsa: remove cross-chip support for HSR
cad69019f2f8 net: dsa: remove cross-chip support for MRP
4b026e82893b net: dsa: combine two holes in struct dsa_switch_tree
b035c88c6a30 net: dsa: move dsa_switch_tree :: ports and lags to first cache line
258030acc93b net: dsa: make dsa_switch :: num_ports an unsigned int
7787ff776398 net: dsa: merge all bools of struct dsa_switch into a single u32
0625125877da net: dsa: move dsa_port :: type near dsa_port :: index
bde82f389af1 net: dsa: merge all bools of struct dsa_port into a single u8
b08db33dabd1 net: dsa: move dsa_port :: stp_state near dsa_port :: mac
7aacb894b1ad net: lan966x: Extend switchdev with mdb support
11b0a27772f5 net: lan966x: Add PGID_GP_START and PGID_GP_END
fc0c3fe7486f net: lan966x: Add function lan966x_mac_ip_learn()
0c94d657d2a4 net: lan966x: Fix the vlan used by host ports
2e49761e4fd1 net: lan966x: Add support for multiple bridge flags
811ba2771182 net: lan966x: Extend switchdev with fdb support
e14f72398df4 net: lan966x: Extend switchdev bridge flags
6d2c186afa5d net: lan966x: Add vlan support.
cf2f60897e92 net: lan966x: Add support to offload the forwarding.
571bb516a869 net: lan966x: Remove .ndo_change_rx_flags
25ee9561ec62 net: lan966x: More MAC table functionality
5ccd66e01cbe net: lan966x: add support for interrupts from analyzer
ef14049f4db9 net: lan966x: Add registers that are used for switch and vlan functionality
7f2973149c22 net: dsa: make tagging protocols connect to individual switches from a tree
e2f01bfe1406 net: dsa: tag_sja1105: fix zeroization of ds->priv on tag proto disconnect
b26980ab2a97 net: lan966x: Fix the configuration of the pcs
950a419d9de1 net: dsa: tag_sja1105: split sja1105_tagger_data into private and public sections
fcbf979a5b4b Revert "net: dsa: move sja1110_process_meta_tstamp inside the tagging protocol driver"
c79e84866d2a net: dsa: tag_sja1105: convert to tagger-owned data
22ee9f8e4011 net: dsa: sja1105: move ts_id from sja1105_tagger_data
bfcf14252220 net: dsa: sja1105: make dp->priv point directly to sja1105_tagger_data
6f6770ab1ce2 net: dsa: sja1105: remove hwts_tx_en from tagger data
d38049bbe760 net: dsa: sja1105: bring deferred xmit implementation in line with ocelot-8021q
a3d74295d790 net: dsa: sja1105: let deferred packets time out when sent to ports going down
35d976802124 net: dsa: tag_ocelot: convert to tagger-owned data
dc452a471dba net: dsa: introduce tagger-owned storage for private and shared data
857fdd74fb38 net: dsa: eliminate dsa_switch_ops :: port_bridge_tx_fwd_{,un}offload
b079922ba2ac net: dsa: add a "tx_fwd_offload" argument to ->port_bridge_join
d3eed0e57d5d net: dsa: keep the bridge_dev and bridge_num as part of the same structure
6a43cba30340 net: dsa: export bridging offload helpers to drivers
936db8a2dba2 net: dsa: rename dsa_port_offloads_bridge to dsa_port_offloads_bridge_dev
41fb0cf1bced net: dsa: hide dp->bridge_dev and dp->bridge_num in drivers behind helpers
36cbf39b5690 net: dsa: hide dp->bridge_dev and dp->bridge_num in the core behind helpers
65144067d360 net: dsa: mv88e6xxx: compute port vlan membership based on dp->bridge_dev comparison
0493fa7927af net: dsa: mv88e6xxx: iterate using dsa_switch_for_each_user_port in mv88e6xxx_port_check_hw_vlan
872bb81dfbc3 net: dsa: mt7530: iterate using dsa_switch_for_each_user_port in bridging ops
947c8746e2c3 net: dsa: assign a bridge number even without TX forwarding offload
3f9bb0301d50 net: dsa: make dp->bridge_num one-based
bb14bfc7eb92 net: lan966x: fix a IS_ERR() vs NULL check in lan966x_create_targets()
cc9cf69eea48 net: lan966x: Fix builds for lan966x driver
a290cf692779 net: lan966x: Fix duplicate check in frame extraction
12c2d0a5b8e2 net: lan966x: add ethtool configuration and statistics
e18aba8941b4 net: lan966x: add mactable support
d28d6d2e37d1 net: lan966x: add port module support
db8bcaad5393 net: lan966x: add the basic lan966x driver
ef136837aaf6 net: dsa: rtl8365mb: set RGMII RX delay in steps of 0.3 ns
b014861d96a6 net: dsa: realtek-smi: don't log an error on EPROBE_DEFER
1e89ad864d03 net: dsa: realtek-smi: fix indirect reg access for ports>3
b3612ccdf284 net: dsa: microchip: implement multi-bridge support
96ca08c05838 net: mscc: ocelot: set up traps for PTP packets
ec15baec3272 net: ptp: add a definition for the UDP port for IEEE 1588 general messages
95706be13b9f net: mscc: ocelot: create a function that replaces an existing VCAP filter
8abe19703825 net: dsa: felix: enable cut-through forwarding between ports by default
a8bd9fa5b527 net: ocelot: remove "bridge" argument from ocelot_get_bridge_fwd_mask
4636440f913b net: dsa: qca8k: Fix spelling mistake "Mismateched" -> "Mismatched"
0898ca67b86e net: dsa: qca8k: fix warning in LAG feature
def975307c01 net: dsa: qca8k: add LAG support
2c1bdbc7e756 net: dsa: qca8k: add support for mirror mode
ba8f870dfa63 net: dsa: qca8k: add support for mdb_add/del
6a3bdc5209f4 net: dsa: qca8k: add set_ageing_time support
4592538bfb0d net: dsa: qca8k: add support for port fast aging
c126f118b330 net: dsa: qca8k: add additional MIB counter and make it dynamic
8b5f3f29a81a net: dsa: qca8k: initial conversion to regmap helper
36b8af12f424 net: dsa: qca8k: move regmap init in probe and set it mandatory
994c28b6f971 net: dsa: qca8k: remove extra mutex_init in qca8k_setup
90ae68bfc2ff net: dsa: qca8k: convert to GENMASK/FIELD_PREP/FIELD_GET
b9133f3ef5a2 net: dsa: qca8k: remove redundant check in parse_port_config
65258b9d8cde net: dsa: qca8k: fix MTU calculation
3b00a07c2443 net: dsa: qca8k: fix internal delay applied to the wrong PAD config
a7e13edf37be net: dsa: felix: restrict psfp rules on ingress port
76c13ede7120 net: dsa: felix: use vcap policer to set flow meter for psfp
77043c37096d net: mscc: ocelot: use index to set vcap policer
23ae3a787771 net: dsa: felix: add stream gate settings for psfp
7d4b564d6add net: dsa: felix: support psfp filter on vsc9959
23e2c506ad6c net: mscc: ocelot: add gate and police action offload to PSFP
5b1918a54a91 net: mscc: ocelot: set vcap IS2 chain to goto PSFP chain
0568c3bf3f34 net: mscc: ocelot: add MAC table stream learn and lookup operations
02d6fdecb9c3 regmap: allow to define reg_update_bits for no bus configuration
5f15d392dcb4 net: dsa: qca8k: make sure PAD0 MAC06 exchange is disabled
ae0393500e3b net: bridge: switchdev: fix shim definition for br_switchdev_mdb_notify
326b212e9cd6 net: bridge: switchdev: consistent function naming
9776457c784f net: bridge: mdb: move all switchdev logic to br_switchdev.c
9ae9ff994b0e net: bridge: split out the switchdev portion of br_mdb_notify
4a6849e46173 net: bridge: move br_vlan_replay to br_switchdev.c
c5f6e5ebc2af net: bridge: provide shim definition for br_vlan_flags
716a30a97a52 net: switchdev: merge switchdev_handle_fdb_{add,del}_to_device
fab9eca88410 net: bridge: create a common function for populating switchdev FDB entries
5cda5272a460 net: bridge: move br_fdb_replay inside br_switchdev.c
9574fb558044 net: bridge: reduce indentation level in fdb_create
f6814fdcfe1b net: bridge: rename br_fdb_insert to br_fdb_add_local
4731b6d6b257 net: bridge: rename fdb_insert to fdb_add_local
5f94a5e276ae net: bridge: remove fdb_insert forward declaration
4682048af0c8 net: bridge: remove fdb_notify forward declaration
425d19cedef8 net: dsa: stop calling dev_hold in dsa_slave_fdb_event
d7d0d423dbaa net: dsa: flush switchdev workqueue when leaving the bridge
0faf890fc519 net: dsa: drop rtnl_lock from dsa_slave_switchdev_event_work
338a3a4745aa net: dsa: introduce locking for the address lists on CPU and DSA ports
cf231b436f7c net: dsa: lantiq_gswip: serialize access to the PCE registers
f7eb4a1c0864 net: dsa: b53: serialize access to the ARL table
edc90d15850c selftests: net: dsa: add a stress test for unlocked FDB operations
016748961ba5 selftests: lib: forwarding: allow tests to not require mz and jq
f239934cffe5 net: dsa: b53: serialize access to the ARL table
f2c4bdf62d76 net: mscc: ocelot: serialize access to the MAC table
1681ae1691ef net: dsa: sja1105: serialize access to the dynamic config interface
643979cf5ec4 net: dsa: sja1105: wait for dynamic config command completion on writes too
992e5cc7be8e net: dsa: tag_8021q: make dsa_8021q_{rx,tx}_vid take dp as argument
5068887a4fbe net: dsa: tag_sja1105: do not open-code dsa_switch_for_each_port
fac6abd5f132 net: dsa: convert cross-chip notifiers to iterate using dp
57d77986e742 net: dsa: remove gratuitous use of dsa_is_{user,dsa,cpu}_port
65c563a67755 net: dsa: do not open-code dsa_switch_for_each_port
d0004a020bb5 net: dsa: remove the "dsa_to_port in a loop" antipattern from the core
82b318983c51 net: dsa: introduce helpers for iterating through ports using dp
d4004422f6f9 net: mscc: ocelot: track the port pvid using a pointer
bfbab3104413 net: mscc: ocelot: add the local station MAC addresses in VID 0
0da1a1c48911 net: mscc: ocelot: allow a config where all bridge VLANs are egress-untagged
90e0aa8d108d net: mscc: ocelot: convert the VLAN masks to a list
62a22bcbd30e net: mscc: ocelot: add a type definition for REW_TAG_CFG_TAG_CFG
040e926f5813 net: dsa: qca8k: tidy for loop in setup and add cpu port check
9ca482a246f0 net: dsa: sja1105: parse {rx, tx}-internal-delay-ps properties for RGMII delays
4af2950c50c8 net: dsa: realtek-smi: add rtl8365mb subdriver for RTL8365MB-VC
1521d5adfc2b net: dsa: tag_rtl8_4: add realtek 8 byte protocol 4 tag
9cb8edda2157 net: dsa: move NET_DSA_TAG_RTL4_A to right place in Kconfig/Makefile
7bbbbfaa7a1b ether: add EtherType for proprietary Realtek protocols
fd0bb28c547f net: dsa: qca8k: move port config to dedicated struct
cef08115846e net: dsa: qca8k: set internal delay also for sgmii
f477d1c8bdbe net: dsa: qca8k: add support for QCA8328
ed7988d77fbf dt-bindings: net: dsa: qca8k: document support for qca8328
362bb238d8bf net: dsa: qca8k: add support for pws config reg
924087c5c3d4 dt-bindings: net: dsa: qca8k: Document qca,led-open-drain binding
bbc4799e8bb6 net: dsa: qca8k: add explicit SGMII PLL enable
13ad5ccc093f dt-bindings: net: dsa: qca8k: Document qca,sgmii-enable-pll
5654ec78dd7e net: dsa: qca8k: rework rgmii delay logic and scan for cpu port 6
3fcf734aa482 net: dsa: qca8k: add support for cpu port 6
731d613338ec dt-bindings: net: dsa: qca8k: Document support for CPU port 6
6c43809bf1be net: dsa: qca8k: add support for sgmii falling edge
fdbf35df9c09 dt-bindings: net: dsa: qca8k: Add SGMII clock phase properties
d8b6f5bae6d3 dsa: qca8k: add mac_power_sel support
39e222bfd7f3 net: dsa: unregister cross-chip notifier after ds->ops->teardown
339e75f6b9a0 net: dsa: rtl8366rb: remove unneeded semicolon
e674cfd08537 net: dsa: rtl8366rb: Support setting STP state
1fbd19e10b73 net: dsa: rtl8366rb: Support fast aging
56d8bb71a811 net: dsa: rtl8366rb: Support disabling learning
5ca721c54d86 net: dsa: tag_ocelot: set the classified VLAN during xmit
e8c0722927e8 net: mscc: ocelot: write full VLAN TCI in the injection header
de5bbb6f7e4c net: mscc: ocelot: support egress VLAN rewriting via VCAP ES0
55b115c7ecd9 net: dsa: rtl8366rb: Use core filtering tracking
d310b14ae748 net: dsa: rtl8366: Drop and depromote pointless prints
a4eff910ec63 net: dsa: rtl8366rb: Rewrite weird VLAN filering enablement
7776e33c68ae net: dsa: rtl8366: Drop custom VLAN set-up
d5a680295be2 net: dsa: rtl8366rb: Support bridge offloading
bd936bd53b2d net: dsa: Move devlink registration to be last devlink command
6d709cadfde6 net: dsa: move sja1110_process_meta_tstamp inside the tagging protocol driver
68a81bb2eebd net: dsa: sja1105: remove sp->dp
db4278c55fa5 devlink: Make devlink_register to be void
4dcd183fbd67 net: wwan: iosm: devlink registration

There are 2 conflicts expected during merging this patch set due to net
<-> net-next overlaps at the time. One is in include/linux/dsa/sja1105.h
and the other is in net/dsa/dsa2.c. See the resolutions in my git tree
and make sure to enable git rerere so that you don't have to redo them
every time you recreate the branch.

For sorting a list of commits chronologically, I have this:

$ cat ~/bin/git-sort-commit-list
#!/bin/bash

set -e -u -o pipefail

error() {
	local lineno="$1"
	local code="${2:-1}"

	echo "Error on line ${lineno}; status ${code}."
	exit "${code}"
}
trap 'error ${LINENO}' ERR

usage() {
	echo "Usage:"
	echo "$0 --commit-file <file> --oldest-commit <ref> --newest-commit <ref>"
	exit
}

argc=$#
argv=( "$@" )

if [ $argc -lt 6 ]; then
	usage
fi

cmd="cat"

i=0
while [ $i -lt $argc ]; do
	key="${argv[$i]}"
	i=$((i + 1))
	case "$key" in
	-c|--commit-file)
		file="${argv[$i]}"
		i=$((i + 1))
		;;
	-n|--newest-commit)
		newest="${argv[$i]}"
		i=$((i + 1))
		;;
	-o|--oldest-commit)
		oldest="${argv[$i]}"
		i=$((i + 1))
		;;
	*)
		usage
		;;
	esac
done

for rev in $(git rev-list "$newest" ^"$oldest"); do
	match="$(grep $(echo ${rev} | head -c 12) ${file} | uniq || :)"
	if [ -n "${match}" ]; then
		echo ${match}
	fi
done

The other script is for the backporting itself:

[tigrisor@skbuf /opt/linux] $ cat ~/bin/git-backport
#!/bin/bash

set -e -u -o pipefail

error() {
	local lineno="$1"
	local code="${2:-1}"

	echo "Error on line ${lineno}; status ${code}."
	exit "${code}"
}
trap 'error ${LINENO}' ERR

usage() {
	echo "Usage:"
	echo "$0 --commit-file <file> --base-branch <ref> --branch-name <string> [--reverse]"
	exit
}

argc=$#
argv=( "$@" )

if [ $argc -lt 6 ]; then
	usage
fi

cmd="cat"

i=0
while [ $i -lt $argc ]; do
	key="${argv[$i]}"
	i=$((i + 1))
	case "$key" in
	-c|--commit-file)
		file="${argv[$i]}"
		i=$((i + 1))
		;;
	-b|--branch-name)
		branch_name="${argv[$i]}"
		i=$((i + 1))
		;;
	-B|--base-branch)
		base_branch="${argv[$i]}"
		i=$((i + 1))
		;;
	-r|--reverse)
		cmd="tac"
		i=$((i + 1))
		;;
	*)
		usage
		;;
	esac
done

git checkout -B "${branch_name}"
git reset --hard "${base_branch}"
GIT_SEQUENCE_EDITOR="${cmd} ${file} | awk '{ print \"pick \" \$0; }' >" \
	git rebase -i --rerere-autoupdate "${base_branch}"

I run it using:

$ git-backport --commit-file stable-commits.txt --base-branch linux-5.15.y --branch-name dsa-5.15.y --reverse

You can add commits to the commit list pretty much anywhere, and run the sorting script afterwards:

$ git sort-commit-list --commit-file stable-commits.txt --oldest-commit v5.15 --newest-commit 5dc760d12082 | tee stable-commits-sorted.txt

You'll probably need to add more, and rebase onto a different base branch for OpenWRT. Nonetheless, it should be a valid start.
Have fun and let me know if you have something useful to share back!