[PATCH RFC net-next 0/5] net: ethernet: ti: am65-cpsw: add AF_XDP zero copy support

[Malladi, Meghana]

Hi Roger,

On 5/20/2025 3:53 PM, Roger Quadros wrote:
> This series adds AF_XDP zero coppy support to am65-cpsw driver.
> 
> Tests were performed on AM62x-sk with xdpsock application [1].
> 
> A clear improvement is seen in 64 byte packets on Transmit (txonly)
> and receive (rxdrop).
> 1500 byte test seems to be limited by line rate (1G link) so no
> improvement seen there in packet rate. A test on higher speed link
> (or PHY-less setup) might be worthwile.
> 
> There is some issue during l2fwd with 64 byte packets and benchmark
> results show 0. I'm still investigating this issue.
> 
> AF_XDP performance using 64 byte packets in Kpps.
> Benchmark:	XDP-SKB		XDP-Native	XDP-Native(ZeroCopy)
> rxdrop		317		504		824
> txonly		400		405		757
> l2fwd 		207		264		0
> 
> AF_XDP performance using 1500 byte packets in Kpps.
> Benchmark:	XDP-SKB		XDP-Native	XDP-Native(ZeroCopy)
> rxdrop		82		82		82
> txonly		82		82		82
> l2fwd 		82		82		82
> 
> [1]: https://github.com/xdp-project/bpf-examples/tree/master/AF_XDP-example
> 
> To:
> 
> Signed-off-by: Roger Quadros <rogerq at kernel.org>

This series crashes Linux on am64xx-hsevm, when I tried nfs boot using 
AM65-CPSW-NUSS driver:
logs: 
https://gist.github.com/MeghanaMalladiTI/d655a1c8ca88113ee7f5f57d6ab0ec4c

Seems like you have reverted the fix for the same bug which was reported 
by Siddharth and fixed by Julien: 
https://lore.kernel.org/all/7f7fb71a-6d15-46f1-b63c-b569a2e230b7@baylibre.com/

reverted lines:
		if (!common->ports[port].ndev)
		/* FIXME should we BUG here? */
			continue;

Can you please take a look at it.

> ---
> Roger Quadros (5):
>        net: ethernet: ti: am65-cpsw: fix BPF Program change on multi-port CPSW
>        net: ethernet: ti: am65-cpsw: add XSK pool helpers
>        net: ethernet: ti: am65-cpsw: Add AF_XDP zero copy for RX
>        net: ethernet: ti: am65-cpsw: Add AF_XDP zero copy for TX
>        net: ethernet: ti: am65-cpsw: enable zero copy in XDP features
> 
>   drivers/net/ethernet/ti/Makefile         |   2 +-
>   drivers/net/ethernet/ti/am65-cpsw-nuss.c | 526 +++++++++++++++++++++++++++----
>   drivers/net/ethernet/ti/am65-cpsw-nuss.h |  37 ++-
>   drivers/net/ethernet/ti/am65-cpsw-xdp.c  | 155 +++++++++
>   4 files changed, 656 insertions(+), 64 deletions(-)
> ---
> base-commit: 9f607dc39b6658ba8ea647bd99725e68c66071b7
> change-id: 20250225-am65-cpsw-xdp-zc-2af9e4be1356
> 
> Best regards,

-- 
Thanks,
Meghana Malladi