From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D1BAC43460 for ; Fri, 9 Apr 2021 16:25:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5B7A461074 for ; Fri, 9 Apr 2021 16:25:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234066AbhDIQZU (ORCPT ); Fri, 9 Apr 2021 12:25:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:33548 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234330AbhDIQZJ (ORCPT ); Fri, 9 Apr 2021 12:25:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D43F76103E; Fri, 9 Apr 2021 16:24:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617985496; bh=1I9bScnOyLvJ83T0qEAguJ1dktfatEjvCVMDfYDNpdU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=E6N02hx3tx6qyuu8+BjuOLRJAwSPuoelG+9wGzt1N6WM4unuY8fvu9BjHL7HUf6s/ UWiwd/6WFIk+VR0xIEJPI0Q/rJ5IUARhRo+/UDWsjDwtIC37IzrQCGl/kHcDcgDrCs Rcnj1qvGT7MNF9QIXCr6XTdzCeXiTJ7EJyqKAOg1l3tv+wApPUnKWIeA83sVRNVxvG qJK+vPqfsYDxR6I5unb/u0jvGVAshHjgOQ663E0MM5oBgXhpl4Itqz2Ys3Czqrpr/1 7XAIvKvXMrLklu85J3vAcEjq8D+1wuSB6qF1vJoZRbr60i5r/WN/lkpQ4/Rr90fdYW 7YiwEm8JwF7PQ== Date: Fri, 9 Apr 2021 18:24:51 +0200 From: Lorenzo Bianconi To: Vladimir Oltean Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, lorenzo.bianconi@redhat.com, davem@davemloft.net, kuba@kernel.org, ast@kernel.org, daniel@iogearbox.net, shayagr@amazon.com, sameehj@amazon.com, john.fastabend@gmail.com, dsahern@kernel.org, brouer@redhat.com, echaudro@redhat.com, jasowang@redhat.com, alexander.duyck@gmail.com, saeed@kernel.org, maciej.fijalkowski@intel.com Subject: Re: [PATCH v8 bpf-next 03/14] net: mvneta: update mb bit before passing the xdp buffer to eBPF layer Message-ID: References: <7a56776d5e2053755854dd668bb08a5e369ef722.1617885385.git.lorenzo@kernel.org> <20210408181935.hrouvsh6hroof4jl@skbuf> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="DaDbQeGnh54LyJSO" Content-Disposition: inline In-Reply-To: <20210408181935.hrouvsh6hroof4jl@skbuf> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org --DaDbQeGnh54LyJSO Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > On Thu, Apr 08, 2021 at 02:50:55PM +0200, Lorenzo Bianconi wrote: > > Update multi-buffer bit (mb) in xdp_buff to notify XDP/eBPF layer and > > XDP remote drivers if this is a "non-linear" XDP buffer. Access > > xdp_shared_info only if xdp_buff mb is set. > >=20 > > Signed-off-by: Lorenzo Bianconi > > --- > > drivers/net/ethernet/marvell/mvneta.c | 26 ++++++++++++++++++++------ > > 1 file changed, 20 insertions(+), 6 deletions(-) > >=20 > > diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethern= et/marvell/mvneta.c > > index a52e132fd2cf..94e29cce693a 100644 > > --- a/drivers/net/ethernet/marvell/mvneta.c > > +++ b/drivers/net/ethernet/marvell/mvneta.c > > @@ -2041,12 +2041,16 @@ mvneta_xdp_put_buff(struct mvneta_port *pp, str= uct mvneta_rx_queue *rxq, > > { > > int i; > > =20 > > + if (likely(!xdp->mb)) > > + goto out; > > + >=20 > Is there any particular reason for this extra check? xdp_sinfo->frags[] is initialized just if xdp->mb is set. Regards, Lorenzo >=20 > > for (i =3D 0; i < xdp_sinfo->nr_frags; i++) { > > skb_frag_t *frag =3D &xdp_sinfo->frags[i]; > > =20 > > page_pool_put_full_page(rxq->page_pool, > > xdp_get_frag_page(frag), true); > > } > > +out: > > page_pool_put_page(rxq->page_pool, virt_to_head_page(xdp->data), > > sync_len, true); > > } > > @@ -2246,7 +2250,6 @@ mvneta_swbm_rx_frame(struct mvneta_port *pp, > > { > > unsigned char *data =3D page_address(page); > > int data_len =3D -MVNETA_MH_SIZE, len; > > - struct xdp_shared_info *xdp_sinfo; > > struct net_device *dev =3D pp->dev; > > enum dma_data_direction dma_dir; > > =20 > > @@ -2270,9 +2273,6 @@ mvneta_swbm_rx_frame(struct mvneta_port *pp, > > prefetch(data); > > xdp_prepare_buff(xdp, data, pp->rx_offset_correction + MVNETA_MH_SIZE, > > data_len, false); > > - > > - xdp_sinfo =3D xdp_get_shared_info_from_buff(xdp); > > - xdp_sinfo->nr_frags =3D 0; > > } > > =20 > > static void > > @@ -2307,12 +2307,18 @@ mvneta_swbm_add_rx_fragment(struct mvneta_port = *pp, > > xdp_set_frag_size(frag, data_len); > > xdp_set_frag_page(frag, page); > > =20 > > + if (!xdp->mb) { > > + xdp_sinfo->data_length =3D *size; > > + xdp->mb =3D 1; > > + } > > /* last fragment */ > > if (len =3D=3D *size) { > > struct xdp_shared_info *sinfo; > > =20 > > sinfo =3D xdp_get_shared_info_from_buff(xdp); > > sinfo->nr_frags =3D xdp_sinfo->nr_frags; > > + sinfo->data_length =3D xdp_sinfo->data_length; > > + > > memcpy(sinfo->frags, xdp_sinfo->frags, > > sinfo->nr_frags * sizeof(skb_frag_t)); > > } > > @@ -2327,11 +2333,15 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, s= truct mvneta_rx_queue *rxq, > > struct xdp_buff *xdp, u32 desc_status) > > { > > struct xdp_shared_info *xdp_sinfo =3D xdp_get_shared_info_from_buff(x= dp); > > - int i, num_frags =3D xdp_sinfo->nr_frags; > > skb_frag_t frag_list[MAX_SKB_FRAGS]; > > + int i, num_frags =3D 0; > > struct sk_buff *skb; > > =20 > > - memcpy(frag_list, xdp_sinfo->frags, sizeof(skb_frag_t) * num_frags); > > + if (unlikely(xdp->mb)) { > > + num_frags =3D xdp_sinfo->nr_frags; > > + memcpy(frag_list, xdp_sinfo->frags, > > + sizeof(skb_frag_t) * num_frags); > > + } > > =20 > > skb =3D build_skb(xdp->data_hard_start, PAGE_SIZE); > > if (!skb) > > @@ -2343,6 +2353,9 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, str= uct mvneta_rx_queue *rxq, > > skb_put(skb, xdp->data_end - xdp->data); > > mvneta_rx_csum(pp, desc_status, skb); > > =20 > > + if (likely(!xdp->mb)) > > + return skb; > > + > > for (i =3D 0; i < num_frags; i++) { > > struct page *page =3D xdp_get_frag_page(&frag_list[i]); > > =20 > > @@ -2404,6 +2417,7 @@ static int mvneta_rx_swbm(struct napi_struct *nap= i, > > frame_sz =3D size - ETH_FCS_LEN; > > desc_status =3D rx_status; > > =20 > > + xdp_buf.mb =3D 0; > > mvneta_swbm_rx_frame(pp, rx_desc, rxq, &xdp_buf, > > &size, page); > > } else { > > --=20 > > 2.30.2 > >=20 >=20 --DaDbQeGnh54LyJSO Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTquNwa3Txd3rGGn7Y6cBh0uS2trAUCYHB/0AAKCRA6cBh0uS2t rIn6AP4j0Y5kcCrLUdgz8noICfBLoEx3AXp6q8ZoQwLiSTJuTAEAn+Ebpe1mR5VO yWMU766AiArFPOREdjQ5v22NZJNxDg0= =ozMp -----END PGP SIGNATURE----- --DaDbQeGnh54LyJSO--