[PATCH net-next v5 0/3] airoha: add the capability to configure GDM3/GDM4 as WAN/LAN on demand

[Lorenzo Bianconi]

Add the capability to configure GDM3/GDM4 as WAN/LAN on demand when QoS
offload is created or destroyed.
Make dev->qdma an RCU pointer so the TX path can safely dereference it
without holding RTNL.
Introduce airoha_qdma_start() and airoha_qdma_stop() helpers.

---
Changes in v5:
- Add patch 1/3: use int instead of atomic_t for qdma users counter
- Protect dev->flags with flow_offload_mutex mutex.
- Introduce AIROHA_PRIV_F_QOS in order to handle better WAN/LAN
  switching.
- Link to v4: https://lore.kernel.org/r/20260610-airoha-ethtool-priv_flags-v4-0-60e89cf28fea@kernel.org

Changes in v4:
- Move back QDMA TX/RX DMA enable to airoha_dev_open()/airoha_dev_stop().
- Configure GDM3/4 as WAN if GDM2 is not available in ndo_init()
  callback.
- Protect qdma pointer in airoha_gdm_dev struct using RCU.
- Rely on rtnl_dereference() to access qdma pointer in the control path.
- Add airoha_qdma_start() and airoha_qdma_stop() utility routines in
  patch 1/2
- Link to v3: https://lore.kernel.org/r/20260608-airoha-ethtool-priv_flags-v3-1-3e8e3dc3f715@kernel.org

Changes in v3:
- Do not introduce ethtool private flags support to configure LAN/WAN
  for GDM3/4 and rely on tc qdisc offload for it instead.
- Set GDM3/4 ports as LAN by default.
- Move QDMA TX/RX DMA enable from airoha_dev_open() to airoha_probe()
  and the corresponding disable from airoha_dev_stop() to airoha_qdma_cleanup().
- Link to v2: https://lore.kernel.org/r/20260607-airoha-ethtool-priv_flags-v2-1-742c7aa1e182@kernel.org

Changes in v2:
- Rework airoha_dev_set_wan_flag routine
- Enable GDM_STRIP_CRC_MASK in airoha_disable_gdm2_loopback()
- Do not always reset REG_SRC_PORT_FC_MAP6 in
  airoha_disable_gdm2_loopback() but use the same condition used in
  airoha_enable_gdm2_loopback().
- Link to v1: https://lore.kernel.org/r/20260606-airoha-ethtool-priv_flags-v1-1-401b2c9fe9f1@kernel.org

---
Lorenzo Bianconi (3):
      net: airoha: use int instead of atomic_t for qdma users counter
      net: airoha: refactor QDMA start/stop into reusable helpers
      net: airoha: defer GDM3/GDM4 WAN mode and GDM2 loopback to QoS offload

 drivers/net/ethernet/airoha/airoha_eth.c  | 287 +++++++++++++++++++++++++-----
 drivers/net/ethernet/airoha/airoha_eth.h  |  15 +-
 drivers/net/ethernet/airoha/airoha_ppe.c  |   9 +-
 drivers/net/ethernet/airoha/airoha_regs.h |   1 +
 4 files changed, 262 insertions(+), 50 deletions(-)
---
base-commit: dad4d4b92a9b9f0edb8c66deda049da1b62f6089
change-id: 20260606-airoha-ethtool-priv_flags-b6aa70caa780

Best regards,
-- 
Lorenzo Bianconi <lorenzo at kernel.org>