[PATCH v4 net-next 00/17] PTP support for the SJA1105 DSA driver

From: Vladimir Oltean
Date: Sat Jun 08 2019 - 08:09:58 EST


This patchset adds the following:

- A timecounter/cyclecounter based PHC for the free-running
timestamping clock of this switch.

- A state machine implemented in the DSA tagger for SJA1105, which
keeps track of metadata follow-up Ethernet frames (the switch's way
of transmitting RX timestamps).

Clock manipulations on the actual hardware PTP clock will have to be
implemented anyway, for the TTEthernet block and the time-based ingress
policer.

v3 patchset can be found at:
https://lkml.org/lkml/2019/6/4/954

Changes from v3:

- Made it compile with the SJA1105 DSA driver and PTP driver as modules.

- Reworked/simplified/fixed some issues in 03/17
(dsa_8021q_remove_header) and added an ASCII image that
illustrates the transformation that is taking place.

- Removed a useless check for sja1105_is_link_local from 16/17 (RX
timestamping) which also made previous 08/17 patch ("Move
sja1105_is_link_local to include/linux") useless and therefore dropped.

v2 patchset can be found at:
https://lkml.org/lkml/2019/6/2/146

Changes from v2:

- Broke previous 09/10 patch (timestamping) into multiple smaller
patches.

- Every patch in the series compiles.

v1 patchset can be found at:
https://lkml.org/lkml/2019/5/28/1093

Changes from v1:

- Removed the addition of the DSA .can_timestamp callback.

- Waiting for meta frames is done completely inside the tagger, and all
frames emitted on RX are already partially timestamped.

- Added a global data structure for the tagger common to all ports.

- Made PTP work with ports in standalone mode, by limiting use of the
DMAC-mangling "incl_srcpt" mode only when ports are bridged, aka when
the DSA master is already promiscuous and can receive anything.
Also changed meta frames to be sent at the 01-80-C2-00-00-0E DMAC.

- Made some progress w.r.t. observed negative path delay. Apparently it
only appears when the delay mechanism is the delay request-response
(end-to-end) one. If peer delay is used (-P), the path delay is
positive and appears reasonable for an 1000Base-T link (485 ns in
steady state).

SJA1105 as PTP slave (OC) with E2E path delay:

ptp4l[55.600]: master offset 8 s2 freq +83677 path delay -2390
ptp4l[56.600]: master offset 17 s2 freq +83688 path delay -2391
ptp4l[57.601]: master offset 6 s2 freq +83682 path delay -2391
ptp4l[58.601]: master offset -1 s2 freq +83677 path delay -2391

SJA1105 as PTP slave (OC) with P2P path delay:

ptp4l[48.343]: master offset 5 s2 freq +83715 path delay 484
ptp4l[48.468]: master offset -3 s2 freq +83705 path delay 485
ptp4l[48.593]: master offset 0 s2 freq +83708 path delay 485
ptp4l[48.718]: master offset 1 s2 freq +83710 path delay 485
ptp4l[48.844]: master offset 1 s2 freq +83710 path delay 485
ptp4l[48.969]: master offset -5 s2 freq +83702 path delay 485
ptp4l[49.094]: master offset 3 s2 freq +83712 path delay 485
ptp4l[49.219]: master offset 4 s2 freq +83714 path delay 485
ptp4l[49.344]: master offset -5 s2 freq +83702 path delay 485
ptp4l[49.469]: master offset 3 s2 freq +83713 path delay 487

Vladimir Oltean (17):
net: dsa: Keep a pointer to the skb clone for TX timestamping
net: dsa: Add teardown callback for drivers
net: dsa: tag_8021q: Create helper function for removing VLAN header
net: dsa: sja1105: Move sja1105_change_tpid into
sja1105_vlan_filtering
net: dsa: sja1105: Reverse TPID and TPID2
net: dsa: sja1105: Limit use of incl_srcpt to bridge+vlan mode
net: dsa: sja1105: Export symbols for upcoming PTP driver
net: dsa: sja1105: Add support for the PTP clock
net: dsa: sja1105: Add logic for TX timestamping
net: dsa: sja1105: Build a minimal understanding of meta frames
net: dsa: sja1105: Add support for the AVB Parameters Table
net: dsa: sja1105: Make sja1105_is_link_local not match meta frames
net: dsa: sja1105: Receive and decode meta frames
net: dsa: sja1105: Add a global sja1105_tagger_data structure
net: dsa: sja1105: Increase priority of CPU-trapped frames
net: dsa: sja1105: Add a state machine for RX timestamping
net: dsa: sja1105: Expose PTP timestamping ioctls to userspace

drivers/net/dsa/sja1105/Kconfig | 7 +
drivers/net/dsa/sja1105/Makefile | 1 +
drivers/net/dsa/sja1105/sja1105.h | 29 ++
.../net/dsa/sja1105/sja1105_dynamic_config.c | 2 +
drivers/net/dsa/sja1105/sja1105_main.c | 316 ++++++++++++--
drivers/net/dsa/sja1105/sja1105_ptp.c | 404 ++++++++++++++++++
drivers/net/dsa/sja1105/sja1105_ptp.h | 64 +++
drivers/net/dsa/sja1105/sja1105_spi.c | 35 ++
.../net/dsa/sja1105/sja1105_static_config.c | 62 +++
.../net/dsa/sja1105/sja1105_static_config.h | 10 +
include/linux/dsa/8021q.h | 16 +-
include/linux/dsa/sja1105.h | 34 ++
include/net/dsa.h | 1 +
net/dsa/dsa2.c | 3 +
net/dsa/slave.c | 3 +
net/dsa/tag_8021q.c | 57 ++-
net/dsa/tag_sja1105.c | 213 ++++++++-
17 files changed, 1184 insertions(+), 73 deletions(-)
create mode 100644 drivers/net/dsa/sja1105/sja1105_ptp.c
create mode 100644 drivers/net/dsa/sja1105/sja1105_ptp.h

--
2.17.1