From patchwork Thu May 14 10:51:04 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: 1290137 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=QrGj92cK; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49N7d62HRpz9sV9 for ; Thu, 14 May 2020 20:51:22 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727810AbgENKvW (ORCPT ); Thu, 14 May 2020 06:51:22 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:32254 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727072AbgENKvU (ORCPT ); Thu, 14 May 2020 06:51:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1589453478; 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=hENIVc271T9dVoIScmAiXOssU9Iccm+zn9gVpNT73bY=; b=QrGj92cKX3oltIeo7cmUbpM+6QJo2O64/qaiEx+tVk9WpFinAtlOHK96S/0LgqCQ6/uLAc d1kQrHziTrizX8GUkUAc37+dtdm1rnREEzlv9GETIOrFWILlKrFng3tRwhtzhrmVte48Vc IGBAbIIcAkTx61axt8+rWCoIHyPvMB4= 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-425-G4jupeuJMjGsRFepFlTiLQ-1; Thu, 14 May 2020 06:51:15 -0400 X-MC-Unique: G4jupeuJMjGsRFepFlTiLQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D8BA61899536; Thu, 14 May 2020 10:51:12 +0000 (UTC) Received: from firesoul.localdomain (unknown [10.40.208.32]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0645C76E99; Thu, 14 May 2020 10:51:06 +0000 (UTC) Received: from [192.168.42.3] (localhost [IPv6:::1]) by firesoul.localdomain (Postfix) with ESMTP id 0439C300020FC; Thu, 14 May 2020 12:51:05 +0200 (CEST) Subject: [PATCH net-next v4 25/33] i40e: add XDP frame size to driver From: Jesper Dangaard Brouer To: sameehj@amazon.com Cc: Jesper Dangaard Brouer , netdev@vger.kernel.org, bpf@vger.kernel.org, =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= , Daniel Borkmann , Alexei Starovoitov , "David S. Miller" , John Fastabend , Alexander Duyck , Jeff Kirsher , David Ahern , Ilias Apalodimas , Lorenzo Bianconi , Saeed Mahameed , Tariq Toukan Date: Thu, 14 May 2020 12:51:04 +0200 Message-ID: <158945346494.97035.12809400414566061815.stgit@firesoul> In-Reply-To: <158945314698.97035.5286827951225578467.stgit@firesoul> References: <158945314698.97035.5286827951225578467.stgit@firesoul> User-Agent: StGit/0.19 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@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 | 30 +++++++++++++++++++++++---- 1 file changed, 25 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..a3772beffe02 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -1507,6 +1507,22 @@ static inline unsigned int i40e_rx_offset(struct i40e_ring *rx_ring) return ring_uses_build_skb(rx_ring) ? I40E_SKB_PAD : 0; } +static 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 +2262,11 @@ 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 +2349,9 @@ 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 +2406,10 @@ 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); }