Add XSK support to the MACB/GEM driver.
Tested on Mobileye EyeQ5 (MIPS) evaluation board.
Applies on top of net-next (4ad96a7c9e2c) and Paolo's XDP work [0].

I don't have good Rx benchmark numbers yet, sorry, mostly because of
userspace tooling issues around eBPF/XDP and MIPS. In copy mode it only
means slowdowns, but in zero-copy, as we work with a fixed amount of
buffers, it causes allocation errors.

--

The bulk of the work is dealing with a second allocator. Throughout, we
now use queue->page_pool or queue->xsk_pool. The former gives us raw
buffers which we need to wrap inside xdp_buff and the latter allocates
xdp_buff, meaning less work.

To simplify the implementation, attaching an XSK pool implies closing
and reopening the interface. It could be improved over time as
currently attaching AF_XDP socket in zero-copy mode means we
close/reopen twice: once for the XDP program, once for the XSK pool.

First three patches are cleanup.

   [PATCH net-next 1/8] net: macb: make rx error messages rate-limited
   [PATCH net-next 2/8] net: macb: account for stats in Rx XDP codepaths
   [PATCH net-next 3/8] net: macb: account for stats in Tx XDP codepaths

Then comes preparation work.

   [PATCH net-next 4/8] net: macb: drop handling of recycled buffers in gem_rx_refill()
   [PATCH net-next 5/8] net: macb: move macb_xdp_submit_frame() body to helper function

And finally the XSK codepaths.

   [PATCH net-next 6/8] net: macb: add infrastructure for XSK buffer pool
   [PATCH net-next 7/8] net: macb: add Rx zero-copy AF_XDP support
   [PATCH net-next 8/8] net: macb: add Tx zero-copy AF_XDP support

Thanks,
Have a nice day,
Théo

[0]: https://lore.kernel.org/netdev/20260302115232.1430640-1-pvalerio@redhat.com/

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
---
Théo Lebrun (8):
      net: macb: make rx error messages rate-limited
      net: macb: account for stats in Rx XDP codepaths
      net: macb: account for stats in Tx XDP codepaths
      net: macb: drop handling of recycled buffers in gem_rx_refill()
      net: macb: move macb_xdp_submit_frame() body to helper function
      net: macb: add infrastructure for XSK buffer pool
      net: macb: add Rx zero-copy AF_XDP support
      net: macb: add Tx zero-copy AF_XDP support

 drivers/net/ethernet/cadence/macb.h      |   2 +
 drivers/net/ethernet/cadence/macb_main.c | 668 +++++++++++++++++++++----------
 2 files changed, 468 insertions(+), 202 deletions(-)
---
base-commit: 06d25a140f34f5879d0731117d4d62a7dd3824a9
change-id: 20260225-macb-xsk-452c0c802436

Best regards,
-- 
Théo Lebrun <theo.lebrun@bootlin.com>

On Wed, 04 Mar 2026 19:24:23 +0100 Théo Lebrun wrote:
> Applies on top of net-next (4ad96a7c9e2c) and Paolo's XDP work [0].

You have to wait until dependencies are merged.
If you want to post in the meantime is has to be as an RFC
-- 
pw-bot: cr