[PATCH net-next v9 0/3] Add minimal XDP support to TI AM65 CPSW Ethernet driver

[Julien Panis <jpanis@baylibre.com>]

This patch adds XDP support to TI AM65 CPSW Ethernet driver.

The following features are implemented: NETDEV_XDP_ACT_BASIC,
NETDEV_XDP_ACT_REDIRECT, and NETDEV_XDP_ACT_NDO_XMIT.

Zero-copy and non-linear XDP buffer supports are NOT implemented.

Besides, the page pool memory model is used to get better performance.

Signed-off-by: Julien Panis <jpanis@baylibre.com>
---
Changes in v9:
- In k3_cppi_desc_pool_destroy(), free memory allocated for pool.
- In k3_cppi_desc_pool_create_name() function, remove unnecessary
error messages on mem alloc failures.
- In k3_cppi_desc_pool_create_name() function, move desc_infos alloc
forward to leverage pool_name freeing in gen_pool_destroy().
- In k3_cppi_desc_pool_create_name() function, remove unnecessary
'ret = -ENOMEM' since ret is already initialized with -ENOMEM value.
- For rx, do not build the skb upfront any more, Instead, give the page
to the HW then build the skb once HW sends a completion.
- Link to v8: https://lore.kernel.org/r/20240223-am65-cpsw-xdp-basic-v8-0-f3421b58da09@baylibre.com

Changes in v8:
- Fix some warnings reported by patchwork.
- Link to v7: https://lore.kernel.org/r/20240223-am65-cpsw-xdp-basic-v7-0-c3857c82dadb@baylibre.com

Changes in v7:
- Move xdp_do_flush() function call in am65_cpsw_nuss_rx_poll().
- Link to v6: https://lore.kernel.org/r/20240223-am65-cpsw-xdp-basic-v6-0-212eeff5bd5f@baylibre.com

Changes in v6:
- In k3_cppi_*() functions, use const qualifier when the content of
pool is not modified.
- Add allow_direct bool parameter to am65_cpsw_alloc_skb() function
for direct use by page_pool_put_full_page().
- Link to v5: https://lore.kernel.org/r/20240223-am65-cpsw-xdp-basic-v5-0-bc1739170bc6@baylibre.com

Changes in v5:
- In k3_cppi_desc_pool_destroy(), free memory allocated for desc_infos.
- Link to v4: https://lore.kernel.org/r/20240223-am65-cpsw-xdp-basic-v4-0-2e45e5dec048@baylibre.com

Changes in v4:
- Add skb_mark_for_recycle() in am65_cpsw_nuss_rx_packets() function.
- Specify napi page pool parameter in am65_cpsw_create_xdp_rxqs() function.
- Add benchmark numbers (with VS without page pool) in the commit description.
- Add xdp_do_flush() in am65_cpsw_run_xdp() function for XDP_REDIRECT case.
- Link to v3: https://lore.kernel.org/r/20240223-am65-cpsw-xdp-basic-v3-0-5d944a9d84a0@baylibre.com

Changes in v3:
- Fix a potential issue with TX buffer type, which is now set for each buffer.
- Link to v2: https://lore.kernel.org/r/20240223-am65-cpsw-xdp-basic-v2-0-01c6caacabb6@baylibre.com

Changes in v2:
- Use page pool memory model instead of MEM_TYPE_PAGE_ORDER0.
- In am65_cpsw_alloc_skb(), release reference on the page pool page
in case of error returned by build_skb().
- [nit] Cleanup am65_cpsw_nuss_common_open/stop() functions.
- [nit] Arrange local variables in reverse xmas tree order.
- Link to v1: https://lore.kernel.org/r/20240223-am65-cpsw-xdp-basic-v1-1-9f0b6cbda310@baylibre.com

---
Julien Panis (3):
      net: ethernet: ti: Add accessors for struct k3_cppi_desc_pool members
      net: ethernet: ti: Add desc_infos member to struct k3_cppi_desc_pool
      net: ethernet: ti: am65-cpsw: Add minimal XDP support

 drivers/net/ethernet/ti/am65-cpsw-nuss.c    | 659 ++++++++++++++++++++++++----
 drivers/net/ethernet/ti/am65-cpsw-nuss.h    |  13 +
 drivers/net/ethernet/ti/k3-cppi-desc-pool.c |  46 +-
 drivers/net/ethernet/ti/k3-cppi-desc-pool.h |   6 +
 4 files changed, 623 insertions(+), 101 deletions(-)
---
base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d
change-id: 20240223-am65-cpsw-xdp-basic-4db828508b48

Best regards,
-- 
Julien Panis <jpanis@baylibre.com>