Merge branch 'stp-rstp-switch-support-for-pru-icssm-ethernet-driver'

Merge branch 'stp-rstp-switch-support-for-pru-icssm-ethernet-driver'

Parvathi Pudi says:

====================
STP/RSTP SWITCH support for PRU-ICSSM Ethernet driver

The DUAL-EMAC patch series for Megabit Industrial Communication Sub-system
(ICSSM), which provides the foundational support for Ethernet functionality
over PRU-ICSS on the TI SOCs (AM335x, AM437x, and AM57x), was merged into
net-next recently [1].

This patch series enhances the PRU-ICSSM Ethernet driver to support bridge
(STP/RSTP) SWITCH mode, which has been implemented using the "switchdev"
framework and interacts with the "mstp daemon" for STP and RSTP management
in userspace.

When the  SWITCH mode is enabled, forwarding of Ethernet packets using
either the traditional store-and-forward mechanism or via cut-through is
offloaded to the two PRU based Ethernet interfaces available within the
ICSSM. The firmware running on the PRU inspects the bridge port states and
performs necessary checks before forwarding a packet. This improves the
overall system performance and significantly reduces the packet forwarding
latency.

Protocol switching from Dual-EMAC to bridge (STP/RSTP) SWITCH mode can be
done as follows.

Assuming eth2 and eth3 are the two physical ports of the ICSS2 instance:

>> brctl addbr br0
>> ip maddr add 01:80:c2:00:00:00 dev br0
>> ip link set dev br0 address $(cat /sys/class/net/eth2/address)
>> brctl addif br0 eth2
>> brctl addif br0 eth3
>> mstpd
>> brctl stp br0 on
>> mstpctl setforcevers br0 rstp
>> ip link set dev br0 up

To revert back to the default dual EMAC mode, the steps are as follows:

>> ip link set dev br0 down
>> brctl delif br0 eth2
>> brctl delif br0 eth3
>> brctl delbr br0

The patches presented in this series have gone through the patch verification
tools and no warnings or errors are reported.
====================

Link: https://patch.msgid.link/20260130124559.1182780-1-parvathi@couthit.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>