[RFC PATCH v2 0/3] Introduce switch mode support for ICSSG driver

[MD Danish Anwar <danishanwar@ti.com>]

This series adds support for switch-mode for ICSSG driver. This series
also introduces helper APIs to configure firmware maintained FDB
(Forwarding Database) and VLAN tables. These APIs are later used by ICSSG
driver in switch mode.

Now the driver will boot by default in dual EMAC mode. When first ICSSG
interface is added to bridge driver will still be in EMAC mode. As soon as
second ICSSG interface is added to same bridge, switch-mode will be
enabled and switch firmwares will be loaded to PRU cores. The driver will
remain in dual EMAC mode if ICSSG interfaces are added to two different
bridges or if two differnet interfaces (One ICSSG, one other) is added to
the same bridge. We'll only enable is_switch_mode flag when two ICSSG
interfaces are added to same bridge.

We start in dual MAC mode. Let's say lan0 and lan1 are ICSSG interfaces

ip link add name br0 type bridge
ip link set lan0 master br0

At this point, we get a CHANGEUPPER event. Only one port is a member of
the bridge, so we will still be in dual MAC mode.

ip link set lan1 master br0

We get a second CHANGEUPPER event, the secind interface lan1 is also ICSSG
interface so we will set the is_switch_mode flag and when interfaces are
brought up again, ICSSG switch firmwares will be loaded to PRU Cores.

There are some other cases to consider as well. 

ip link add name br0 type bridge
ip link add name br1 type bridge

ip link set lan0 master br0
ip link set ppp0 master br0

Here we are adding lan0 (ICSSG) and ppp0 (non ICSSG) to same bridge, as
they both are not ICSSG, we will still be running in dual EMAC mode.

ip link set lan1 master br1
ip link set vpn0 master br1

Here we are adding lan1 (ICSSG) and vpn0 (non ICSSG) to same bridge, as
they both are not ICSSG, we will still be running in dual EMAC mode.


This is v2 of the series [1]. It addresses commenst made on v1 [1].

Changes from v1 to v2:
*) Removed TAPRIO support patch from this series.
*) Stopped using devlink for enabling switch-mode as suggested by Andrew L
*) Added read_poll_timeout() in patch 1 / 3 as suggested by Andrew L.

[1] https://lore.kernel.org/all/20230830110847.1219515-4-danishanwar@ti.com/

Thanks and Regards,
Md Danish Anwar

MD Danish Anwar (3):
  net: ti: icssg-prueth: Add helper functions to configure FDB
  net: ti: icssg-switch: Add switchdev based driver for ethernet switch
    support
  net: ti: icssg-prueth: Add support for ICSSG switch firmware

 drivers/net/ethernet/ti/Kconfig               |   1 +
 drivers/net/ethernet/ti/Makefile              |   3 +-
 drivers/net/ethernet/ti/icssg/icssg_config.c  | 324 +++++++++++-
 drivers/net/ethernet/ti/icssg/icssg_config.h  |  26 +
 drivers/net/ethernet/ti/icssg/icssg_prueth.c  | 199 +++++++-
 drivers/net/ethernet/ti/icssg/icssg_prueth.h  |  36 ++
 .../net/ethernet/ti/icssg/icssg_switchdev.c   | 478 ++++++++++++++++++
 .../net/ethernet/ti/icssg/icssg_switchdev.h   |  13 +
 8 files changed, 1067 insertions(+), 13 deletions(-)
 create mode 100644 drivers/net/ethernet/ti/icssg/icssg_switchdev.c
 create mode 100644 drivers/net/ethernet/ti/icssg/icssg_switchdev.h

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2.34.1