Re: [PATCH net-next 00/12] Add tc-mqprio and tc-taprio support for preemptible traffic classes

Hi Vladimir!

On Sat, 2023-02-18 at 17:20 +0200, Vladimir Oltean wrote:

On Fri, Feb 17, 2023 at 01:21:14AM +0200, Vladimir Oltean wrote:

quoted

The last RFC in August 2022 contained a proposal for the UAPI of
both
TSN standards which together form Frame Preemption (802.1Q and
802.3):
https://patchwork.kernel.org/project/netdevbpf/cover/20220816222920.1952936-1-vladimir.oltean@nxp.com/

It wasn't clear at the time whether the 802.1Q portion of Frame
Preemption
should be exposed via the tc qdisc (mqprio, taprio) or via some
other
layer (perhaps also ethtool like the 802.3 portion).

So the 802.3 portion got submitted separately and finally was
accepted:
https://patchwork.kernel.org/project/netdevbpf/cover/20230119122705.73054-1-vladimir.oltean@nxp.com/

leaving the only remaining question: how do we expose the 802.1Q
bits?

This series proposes that we use the Qdisc layer, through separate
(albeit very similar) UAPI in mqprio and taprio, and that both
these
Qdiscs pass the information down to the offloading device driver
through
the common mqprio offload structure (which taprio also passes).

Implementations are provided for the NXP LS1028A on-board Ethernet
(enetc, felix).

Some patches should have maybe belonged to separate series, leaving
here
only patches 09/12 - 12/12, for ease of review. That may be true,
however due to a perceived lack of time to wait for the
prerequisite
cleanup to be merged, here they are all together.

Vladimir Oltean (12):
  net: enetc: rename "mqprio" to "qopt"
  net: mscc: ocelot: add support for mqprio offload
  net: dsa: felix: act upon the mqprio qopt in taprio offload
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  net: ethtool: create and export ethtool_dev_mm_supported()
  net/sched: mqprio: simplify handling of nlattr portion of
TCA_OPTIONS
  net/sched: mqprio: add extack to mqprio_parse_nlattr()
  net/sched: mqprio: add an extack message to mqprio_parse_opt()
  net/sched: mqprio: allow per-TC user input of FP adminStatus
  net/sched: taprio: allow per-TC user input of FP adminStatus
  net: mscc: ocelot: add support for preemptible traffic classes
  net: enetc: add support for preemptible traffic classes

 drivers/net/dsa/ocelot/felix_vsc9959.c        |  44 ++++-
 drivers/net/ethernet/freescale/enetc/enetc.c  |  31 ++-
 drivers/net/ethernet/freescale/enetc/enetc.h  |   1 +
 .../net/ethernet/freescale/enetc/enetc_hw.h   |   4 +
 drivers/net/ethernet/mscc/ocelot.c            |  51 +++++
 drivers/net/ethernet/mscc/ocelot.h            |   2 +
 drivers/net/ethernet/mscc/ocelot_mm.c         |  56 ++++++
 include/linux/ethtool_netlink.h               |   6 +
 include/net/pkt_sched.h                       |   1 +
 include/soc/mscc/ocelot.h                     |   6 +
 include/uapi/linux/pkt_sched.h                |  17 ++
 net/ethtool/mm.c                              |  24 ++-
 net/sched/sch_mqprio.c                        | 182
+++++++++++++++---
 net/sched/sch_mqprio_lib.c                    |  14 ++
 net/sched/sch_mqprio_lib.h                    |   2 +
 net/sched/sch_taprio.c                        |  65 +++++--
 16 files changed, 459 insertions(+), 47 deletions(-)

-- 
2.34.1

Seeing that there is no feedback on the proposed UAPI, I'd be tempted
to resend this, with just the modular build fixed (export the
ethtool_dev_mm_supported() symbol).

Would anyone hate me for doing this, considering that the merge
window
is close? Does anyone need some time to take a closer look at this,
or
think about a better alternative?

Do you have the iproute2 part? Sorry if I missed it, but it would be
nice to see how is that UAPI exposed for the config tools. Is there any
new parameter for mqprio/taprio?

Best,
Ferenc