Merge branch 'introduce-hsr-offload-support-for-icssg'

Merge branch 'introduce-hsr-offload-support-for-icssg'

MD Danish Anwar says:

====================
Introduce HSR offload support for ICSSG

This series introduces HSR offload support for ICSSG driver. To support HSR
offload to hardware, ICSSG HSR firmware is used.

This series introduces,
1. HSR frame offload support for ICSSG driver.
2. HSR Tx Packet duplication offload
3. HSR Tx Tag and Rx Tag offload
4. Multicast filtering support in HSR offload mode.
5. Dependencies related to IEP.

HSR Test Setup:
--------------

     ___________           ___________           ___________
    |           | Link AB |           | Link BC |           |
  __|   AM64*   |_________|   AM64    |_________|   AM64*   |___
 |  | Station A |         | Station B |         | Station C |   |
 |  |___________|         |___________|         |___________|   |
 |                                                              |
 |______________________________________________________________|
                            Link CA
 *Could be any device that supports two ethernet interfaces.

Steps to switch to HSR frame forward offload mode:
-------------------------------------------------
Example assuming eth1, eth2 ports of ICSSG1 on AM64-EVM

  1) Enable HSR offload for both interfaces
      ethtool -K eth1 hsr-fwd-offload on
      ethtool -K eth1 hsr-dup-offload on
      ethtool -K eth1 hsr-tag-ins-offload on
      ethtool -K eth1 hsr-tag-rm-offload on

      ethtool -K eth2 hsr-fwd-offload on
      ethtool -K eth2 hsr-dup-offload on
      ethtool -K eth2 hsr-tag-ins-offload on
      ethtool -K eth2 hsr-tag-rm-offload on

  2) Create HSR interface and add slave interfaces to it
      ip link add name hsr0 type hsr slave1 eth1 slave2 eth2 \
    supervision 45 version 1

  3) Add IP address to the HSR interface
      ip addr add <IP_ADDR>/24 dev hsr0

  4) Bring up the HSR interface
      ip link set hsr0 up

Switching back to previous mode:
--------------------------------
  1) Delete HSR interface
      ip link delete hsr0

  2) Disable HSR port-to-port offloading mode, packet duplication
      ethtool -K eth1 hsr-fwd-offload off
      ethtool -K eth1 hsr-dup-offload off
      ethtool -K eth1 hsr-tag-ins-offload off
      ethtool -K eth1 hsr-tag-rm-offload off

      ethtool -K eth2 hsr-fwd-offload off
      ethtool -K eth2 hsr-dup-offload off
      ethtool -K eth2 hsr-tag-ins-offload off
      ethtool -K eth2 hsr-tag-rm-offload off

Testing the port-to-port frame forward offload feature:
-----------------------------------------------------
  1) Connect the LAN cables as shown in the test setup.
  2) Configure Station A and Station C in HSR non-offload mode.
  3) Configure Station B is HSR offload mode.
  4) Since HSR is a redundancy protocol, disconnect cable "Link CA",
     to ensure frames from Station A reach Station C only through
     Station B.
  5) Run iperf3 Server on Station C and client on station A.
  7) Check the CPU usage on Station B.

CPU usage report on Station B using mpstat when running UDP iperf3:
-------------------------------------------------------------------

  1) Non-Offload case
  -------------------
  CPU  %usr  %nice  %sys %iowait  %irq  %soft  %steal  %guest   %idle
  all  0.00   0.00  0.50    0.00  3.52  29.15    0.00    0.00   66.83
    0  0.00   0.00  0.00    0.00  7.00  58.00    0.00    0.00   35.00
    1  0.00   0.00  0.99    0.00  0.99   0.00    0.00    0.00   98.02

  2) Offload case
  ---------------
  CPU  %usr  %nice  %sys %iowait  %irq  %soft  %steal  %guest   %idle
  all  0.00   0.00  0.00    0.00  0.50   0.00    0.00    0.00   99.50
    0  0.00   0.00  0.99    0.00  0.00   0.00    0.00    0.00   99.01
    1  0.00   0.00  0.00    0.00  0.00   0.00    0.00    0.00  100.00

Note:
1) At the very least, hsr-fwd-offload must be enabled.
   Without offloading the port-to-port offload, other
   HSR offloads cannot be enabled.

2) hsr-tag-ins-offload and hsr-dup-offload are tightly coupled in
   the firmware implementation. They both need to be enabled / disabled
   together.

v1: https://lore.kernel.org/20240808110800.1281716-1-danishanwar@ti.com/
v2: https://lore.kernel.org/20240813074233.2473876-1-danishanwar@ti.com
v3: https://lore.kernel.org/20240828091901.3120935-1-danishanwar@ti.com/
v4: https://lore.kernel.org/20240904100506.3665892-1-danishanwar@ti.com/
v5: https://lore.kernel.org/20240906111538.1259418-1-danishanwar@ti.com/

[0] https://lore.kernel.org/202409061658.vSwcFJiK-lkp@intel.com/
[1] https://lore.kernel.org/20240828091901.3120935-5-danishanwar@ti.com/
[2] https://lore.kernel.org/20240828091901.3120935-7-danishanwar@ti.com/
[3] https://lore.kernel.org/20240813074233.2473876-2-danishanwar@ti.com/
[4] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=e846be0fba85
====================

Link: https://patch.msgid.link/20240911081603.2521729-1-danishanwar@ti.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>