From patchwork Wed Apr 8 11:52:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jesper Dangaard Brouer X-Patchwork-Id: 221355 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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 0D57BC2BA1A for ; Wed, 8 Apr 2020 11:53:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D66252082D for ; Wed, 8 Apr 2020 11:53:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="FAStVQLc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727929AbgDHLxB (ORCPT ); Wed, 8 Apr 2020 07:53:01 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:23467 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728766AbgDHLxA (ORCPT ); Wed, 8 Apr 2020 07:53:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1586346780; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BcJO2PQZQoTdxh1ktsCU9M3+07NWPu/ha/1VIUeextI=; b=FAStVQLcMzJa3GOlkPljfuVw04iGCA8epbTSIeDuMHpbLkf5HVE31/pMBtfz0vy0YDcC1n reKyJ3x1GOI2yoKSvMX4Ihm6p2xXAD6KezOH2afjGSfgxGAFvsQKqAIZY6SGUOULt4tL/5 zzTo2mHV+CcIw6O4130c5txat589BmE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-40-fWTj1sQ-Mnmm7YMTHvjhIQ-1; Wed, 08 Apr 2020 07:52:55 -0400 X-MC-Unique: fWTj1sQ-Mnmm7YMTHvjhIQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EEAB119067E1; Wed, 8 Apr 2020 11:52:52 +0000 (UTC) Received: from firesoul.localdomain (unknown [10.40.208.40]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6225E99E03; Wed, 8 Apr 2020 11:52:47 +0000 (UTC) Received: from [192.168.42.3] (localhost [IPv6:::1]) by firesoul.localdomain (Postfix) with ESMTP id 7F9EA300020FA; Wed, 8 Apr 2020 13:52:46 +0200 (CEST) Subject: [PATCH RFC v2 26/33] i40e: add XDP frame size to driver From: Jesper Dangaard Brouer To: sameehj@amazon.com Cc: intel-wired-lan@lists.osuosl.org, Jeff Kirsher , Alexander Duyck , Jesper Dangaard Brouer , netdev@vger.kernel.org, bpf@vger.kernel.org, zorik@amazon.com, akiyano@amazon.com, gtzalik@amazon.com, =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= , Daniel Borkmann , Alexei Starovoitov , John Fastabend , Alexander Duyck , Jeff Kirsher , David Ahern , Willem de Bruijn , Ilias Apalodimas , Lorenzo Bianconi , Saeed Mahameed Date: Wed, 08 Apr 2020 13:52:46 +0200 Message-ID: <158634676645.707275.7536684877295305696.stgit@firesoul> In-Reply-To: <158634658714.707275.7903484085370879864.stgit@firesoul> References: <158634658714.707275.7903484085370879864.stgit@firesoul> User-Agent: StGit/0.19 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This driver uses different memory models depending on PAGE_SIZE at compile time. For PAGE_SIZE 4K it uses page splitting, meaning for normal MTU frame size is 2048 bytes (and headroom 192 bytes). For larger MTUs the driver still use page splitting, by allocating order-1 pages (8192 bytes) for RX frames. For PAGE_SIZE larger than 4K, driver instead advance its rx_buffer->page_offset with the frame size "truesize". For XDP frame size calculations, this mean that in PAGE_SIZE larger than 4K mode the frame_sz change on a per packet basis. For the page split 4K PAGE_SIZE mode, xdp.frame_sz is more constant and can be updated once outside the main NAPI loop. The default setting in the driver uses build_skb(), which provides the necessary headroom and tailroom for XDP-redirect in RX-frame (in both modes). There is one complication, which is legacy-rx mode (configurable via ethtool priv-flags). There are zero headroom in this mode, which is a requirement for XDP-redirect to work. The conversion to xdp_frame (convert_to_xdp_frame) will detect this insufficient space, and xdp_do_redirect() call will fail. This is deemed acceptable, as it allows other XDP actions to still work in legacy-mode. In legacy-mode + larger PAGE_SIZE due to lacking tailroom, we also accept that xdp_adjust_tail shrink doesn't work. Cc: intel-wired-lan@lists.osuosl.org Cc: Jeff Kirsher Cc: Alexander Duyck Signed-off-by: Jesper Dangaard Brouer --- drivers/net/ethernet/intel/i40e/i40e_txrx.c | 31 +++++++++++++++++++++++---- 1 file changed, 26 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index b8496037ef7f..1fb6b1004dcb 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -1507,6 +1507,23 @@ static inline unsigned int i40e_rx_offset(struct i40e_ring *rx_ring) return ring_uses_build_skb(rx_ring) ? I40E_SKB_PAD : 0; } +static inline unsigned int i40e_rx_frame_truesize(struct i40e_ring *rx_ring, + unsigned int size) +{ + unsigned int truesize; + +#if (PAGE_SIZE < 8192) + truesize = i40e_rx_pg_size(rx_ring) / 2; /* Must be power-of-2 */ +#else + truesize = i40e_rx_offset(rx_ring) ? + SKB_DATA_ALIGN(size + i40e_rx_offset(rx_ring)) + + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) : + SKB_DATA_ALIGN(size); +#endif + return truesize; +} + + /** * i40e_alloc_mapped_page - recycle or make a new page * @rx_ring: ring to use @@ -2246,13 +2263,11 @@ static void i40e_rx_buffer_flip(struct i40e_ring *rx_ring, struct i40e_rx_buffer *rx_buffer, unsigned int size) { -#if (PAGE_SIZE < 8192) - unsigned int truesize = i40e_rx_pg_size(rx_ring) / 2; + unsigned int truesize = i40e_rx_frame_truesize(rx_ring, size); +#if (PAGE_SIZE < 8192) rx_buffer->page_offset ^= truesize; #else - unsigned int truesize = SKB_DATA_ALIGN(i40e_rx_offset(rx_ring) + size); - rx_buffer->page_offset += truesize; #endif } @@ -2335,6 +2350,9 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget) bool failure = false; struct xdp_buff xdp; +#if (PAGE_SIZE < 8192) + xdp.frame_sz = i40e_rx_frame_truesize(rx_ring, 0); +#endif xdp.rxq = &rx_ring->xdp_rxq; while (likely(total_rx_packets < (unsigned int)budget)) { @@ -2389,7 +2407,10 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget) xdp.data_hard_start = xdp.data - i40e_rx_offset(rx_ring); xdp.data_end = xdp.data + size; - +#if (PAGE_SIZE > 4096) + /* At larger PAGE_SIZE, frame_sz depend on len size */ + xdp.frame_sz = i40e_rx_frame_truesize(rx_ring, size); +#endif skb = i40e_run_xdp(rx_ring, &xdp); }