Re: [PATCH net v2 3/3] octeontx2-pf: Do xdp_do_flush() after redirects.

Kui-Feng Lee
2023-09-18T17:58:44Z

On 9/18/23 08:36, Sebastian Andrzej Siewior wrote:
> xdp_do_flush() should be invoked before leaving the NAPI poll function
> if XDP-redirect has been performed.
>
> Invoke xdp_do_flush() before leaving NAPI.
>
> Cc: Geetha sowjanya <gakula@marvell.com>
> Cc: Subbaraya Sundeep <sbhatta@marvell.com>
> Cc: Sunil Goutham <sgoutham@marvell.com>
> Cc: hariprasad <hkelam@marvell.com>
> Fixes: 06059a1a9a4a5 ("octeontx2-pf: Add XDP support to netdev PF")
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Acked-by: Geethasowjanya Akula <gakula@marvell.com>
> ---
> .../marvell/octeontx2/nic/otx2_txrx.c | 19 +++++++++++++------
> 1 file changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c
> index e77d438489557..53b2a4ef52985 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c
> +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c
> @@ -29,7 +29,8 @@
> static bool otx2_xdp_rcv_pkt_handler(struct otx2_nic *pfvf,
> struct bpf_prog *prog,
> struct nix_cqe_rx_s *cqe,
> - struct otx2_cq_queue *cq);
> + struct otx2_cq_queue *cq,
> + bool *need_xdp_flush);
>
> static int otx2_nix_cq_op_status(struct otx2_nic *pfvf,
> struct otx2_cq_queue *cq)
> @@ -337,7 +338,7 @@ static bool otx2_check_rcv_errors(struct otx2_nic *pfvf,
> static void otx2_rcv_pkt_handler(struct otx2_nic *pfvf,
> struct napi_struct *napi,
> struct otx2_cq_queue *cq,
> - struct nix_cqe_rx_s *cqe)
> + struct nix_cqe_rx_s *cqe, bool *need_xdp_flush)
> {
> struct nix_rx_parse_s *parse = &cqe->parse;
> struct nix_rx_sg_s *sg = &cqe->sg;
> @@ -353,7 +354,7 @@ static void otx2_rcv_pkt_handler(struct otx2_nic *pfvf,
> }
>
> if (pfvf->xdp_prog)
> - if (otx2_xdp_rcv_pkt_handler(pfvf, pfvf->xdp_prog, cqe, cq))
> + if (otx2_xdp_rcv_pkt_handler(pfvf, pfvf->xdp_prog, cqe, cq, need_xdp_flush))
> return;
>
> skb = napi_get_frags(napi);
> @@ -388,6 +389,7 @@ static int otx2_rx_napi_handler(struct otx2_nic *pfvf,
> struct napi_struct *napi,
> struct otx2_cq_queue *cq, int budget)
> {
> + bool need_xdp_flush = false;
> struct nix_cqe_rx_s *cqe;
> int processed_cqe = 0;
>
> @@ -409,13 +411,15 @@ static int otx2_rx_napi_handler(struct otx2_nic *pfvf,
> cq->cq_head++;
> cq->cq_head &= (cq->cqe_cnt - 1);
>
> - otx2_rcv_pkt_handler(pfvf, napi, cq, cqe);
> + otx2_rcv_pkt_handler(pfvf, napi, cq, cqe, &need_xdp_flush);
>
> cqe->hdr.cqe_type = NIX_XQE_TYPE_INVALID;
> cqe->sg.seg_addr = 0x00;
> processed_cqe++;
> cq->pend_cqe--;
> }
> + if (need_xdp_flush)
> + xdp_do_flush();
>
> /* Free CQEs to HW */
> otx2_write64(pfvf, NIX_LF_CQ_OP_DOOR,
> @@ -1354,7 +1358,8 @@ bool otx2_xdp_sq_append_pkt(struct otx2_nic *pfvf, u64 iova, int len, u16 qidx)
> static bool otx2_xdp_rcv_pkt_handler(struct otx2_nic *pfvf,
> struct bpf_prog *prog,
> struct nix_cqe_rx_s *cqe,
> - struct otx2_cq_queue *cq)
> + struct otx2_cq_queue *cq,
> + bool *need_xdp_flush)
> {
> unsigned char *hard_start, *data;
> int qidx = cq->cq_idx;
> @@ -1391,8 +1396,10 @@ static bool otx2_xdp_rcv_pkt_handler(struct otx2_nic *pfvf,
>
> otx2_dma_unmap_page(pfvf, iova, pfvf->rbsize,
> DMA_FROM_DEVICE);
> - if (!err)
> + if (!err) {
> + *need_xdp_flush = true;

Is it possible to call xdp_do_flush() at the first place (here)?

> return true;
> + }
> put_page(page);
> break;