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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4D2ECC433EF for ; Wed, 6 Jul 2022 23:13:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234036AbiGFXNx (ORCPT ); Wed, 6 Jul 2022 19:13:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59344 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234255AbiGFXNb (ORCPT ); Wed, 6 Jul 2022 19:13:31 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3793C2639 for ; Wed, 6 Jul 2022 16:13:29 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id E4878B81EFB for ; Wed, 6 Jul 2022 23:13:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 88533C3411C; Wed, 6 Jul 2022 23:13:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657149206; bh=C7B5aRF20hWFVCaImnZbjKxDPbhY4A+oiFLv4CYC7ks=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aVJ2BIMvyMyrqqsKDnG6wCiCTxhcYvOa+mF3R4oR+vouYwHL/ghIADukKhGL/lsps nKplR0YXMRtHD/lBJKFciefCKiucPbu0F2fxe9KyLPs6j766LZVN5kyMqH0FJV8wZM uieIcHWJZfj4caAp+x6I6Ila+328hN4tiIO0ZngeE6cx2B4R+itDW3iFHssQd3sVal g8QNTuufDe3ofYf0RZoaihLhxTRKgeNX35/cNBb1+M4WtWPtrFO6/ItrURdLy6xu/N TPzmbqIsTAVdRi61QvbqhtADi3IY1/p93m8LA4orNz3o6cIyGvXeCsCWp3n1s30Arq QvIjvsGemL7qA== From: Saeed Mahameed To: "David S. Miller" , Jakub Kicinski , Paolo Abeni , Eric Dumazet Cc: Saeed Mahameed , netdev@vger.kernel.org, Maxim Mikityanskiy , Tariq Toukan Subject: [net 9/9] net/mlx5e: Ring the TX doorbell on DMA errors Date: Wed, 6 Jul 2022 16:13:09 -0700 Message-Id: <20220706231309.38579-10-saeed@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220706231309.38579-1-saeed@kernel.org> References: <20220706231309.38579-1-saeed@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Maxim Mikityanskiy TX doorbells may be postponed, because sometimes the driver knows that another packet follows (for example, when xmit_more is true, or when a MPWQE session is closed before transmitting a packet). However, the DMA mapping may fail for the next packet, in which case a new WQE is not posted, the doorbell isn't updated either, and the transmission of the previous packet will be delayed indefinitely. This commit fixes the described rare error flow by posting a NOP and ringing the doorbell on errors to flush all the previous packets. The MPWQE session is closed before that. DMA mapping in the MPWQE flow is moved to the beginning of mlx5e_sq_xmit_mpwqe, because empty sessions are not allowed. Stop room always has enough space for a NOP, because the actual TX WQE is not posted. Fixes: e586b3b0baee ("net/mlx5: Ethernet Datapath files") Signed-off-by: Maxim Mikityanskiy Reviewed-by: Tariq Toukan Signed-off-by: Saeed Mahameed --- .../net/ethernet/mellanox/mlx5/core/en_tx.c | 39 ++++++++++++++----- 1 file changed, 30 insertions(+), 9 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c index 50d14cec4894..9a7250be229f 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c @@ -341,6 +341,26 @@ static void mlx5e_tx_check_stop(struct mlx5e_txqsq *sq) } } +static void mlx5e_tx_flush(struct mlx5e_txqsq *sq) +{ + struct mlx5e_tx_wqe_info *wi; + struct mlx5e_tx_wqe *wqe; + u16 pi; + + /* Must not be called when a MPWQE session is active but empty. */ + mlx5e_tx_mpwqe_ensure_complete(sq); + + pi = mlx5_wq_cyc_ctr2ix(&sq->wq, sq->pc); + wi = &sq->db.wqe_info[pi]; + + *wi = (struct mlx5e_tx_wqe_info) { + .num_wqebbs = 1, + }; + + wqe = mlx5e_post_nop(&sq->wq, sq->sqn, &sq->pc); + mlx5e_notify_hw(&sq->wq, sq->pc, sq->uar_map, &wqe->ctrl); +} + static inline void mlx5e_txwqe_complete(struct mlx5e_txqsq *sq, struct sk_buff *skb, const struct mlx5e_tx_attr *attr, @@ -459,6 +479,7 @@ mlx5e_sq_xmit_wqe(struct mlx5e_txqsq *sq, struct sk_buff *skb, err_drop: stats->dropped++; dev_kfree_skb_any(skb); + mlx5e_tx_flush(sq); } static bool mlx5e_tx_skb_supports_mpwqe(struct sk_buff *skb, struct mlx5e_tx_attr *attr) @@ -560,6 +581,13 @@ mlx5e_sq_xmit_mpwqe(struct mlx5e_txqsq *sq, struct sk_buff *skb, struct mlx5_wqe_ctrl_seg *cseg; struct mlx5e_xmit_data txd; + txd.data = skb->data; + txd.len = skb->len; + + txd.dma_addr = dma_map_single(sq->pdev, txd.data, txd.len, DMA_TO_DEVICE); + if (unlikely(dma_mapping_error(sq->pdev, txd.dma_addr))) + goto err_unmap; + if (!mlx5e_tx_mpwqe_session_is_active(sq)) { mlx5e_tx_mpwqe_session_start(sq, eseg); } else if (!mlx5e_tx_mpwqe_same_eseg(sq, eseg)) { @@ -569,18 +597,9 @@ mlx5e_sq_xmit_mpwqe(struct mlx5e_txqsq *sq, struct sk_buff *skb, sq->stats->xmit_more += xmit_more; - txd.data = skb->data; - txd.len = skb->len; - - txd.dma_addr = dma_map_single(sq->pdev, txd.data, txd.len, DMA_TO_DEVICE); - if (unlikely(dma_mapping_error(sq->pdev, txd.dma_addr))) - goto err_unmap; mlx5e_dma_push(sq, txd.dma_addr, txd.len, MLX5E_DMA_MAP_SINGLE); - mlx5e_skb_fifo_push(&sq->db.skb_fifo, skb); - mlx5e_tx_mpwqe_add_dseg(sq, &txd); - mlx5e_tx_skb_update_hwts_flags(skb); if (unlikely(mlx5e_tx_mpwqe_is_full(&sq->mpwqe, sq->max_sq_mpw_wqebbs))) { @@ -602,6 +621,7 @@ mlx5e_sq_xmit_mpwqe(struct mlx5e_txqsq *sq, struct sk_buff *skb, mlx5e_dma_unmap_wqe_err(sq, 1); sq->stats->dropped++; dev_kfree_skb_any(skb); + mlx5e_tx_flush(sq); } void mlx5e_tx_mpwqe_ensure_complete(struct mlx5e_txqsq *sq) @@ -1006,5 +1026,6 @@ void mlx5i_sq_xmit(struct mlx5e_txqsq *sq, struct sk_buff *skb, err_drop: stats->dropped++; dev_kfree_skb_any(skb); + mlx5e_tx_flush(sq); } #endif -- 2.36.1