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=-19.7 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,URIBL_BLOCKED,USER_AGENT_GIT 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 CC048C4338F for ; Tue, 24 Aug 2021 16:59:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7CBE61507 for ; Tue, 24 Aug 2021 16:59:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234984AbhHXRAW (ORCPT ); Tue, 24 Aug 2021 13:00:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:39508 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233519AbhHXQ54 (ORCPT ); Tue, 24 Aug 2021 12:57:56 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CB60B6140B; Tue, 24 Aug 2021 16:56:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629824220; bh=UHZ+5rnbsQz85vmQU3yo/xBasy7UT7+O3ZdaPNbridM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k9UEYimNsIWRE8n+kRjVK4XcKw8ciF/XsPuPesBPYElVNI7rYoeq2Wwo3ZpohAGPM wiCFO+0sG/u3TPlENVGXpRpHXkm4lo/B+G1GZuwXyvwRUvivoKb/2MlK3vNRUa/Ap2 kKuIwI3+PqP5EaR4e0JfOmCxUT9Rsqx2Yh+BiVoeF6efBNs2YIsaUoKInKUYE1BJtR hzzgPNzX7l+ZcP0MQk32I/Sh+6ntbAh1DAZzOUNA9oflAe93IT2cAkxrinz/5R2jDM f2gdYZUR0KEBoeAb1H/0wmm6ByfkklL536tGlw91pDj/NxXi3dqS6uQGXbSswWBtmB HXXJByxS7QmQA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jakub Kicinski , Michael Chan , Edwin Peer , Sasha Levin Subject: [PATCH 5.13 053/127] bnxt: make sure xmit_more + errors does not miss doorbells Date: Tue, 24 Aug 2021 12:54:53 -0400 Message-Id: <20210824165607.709387-54-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210824165607.709387-1-sashal@kernel.org> References: <20210824165607.709387-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.13.13-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.13.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.13.13-rc1 X-KernelTest-Deadline: 2021-08-26T16:55+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jakub Kicinski [ Upstream commit e8d8c5d80f5e9d4586c68061b62c642752289095 ] skbs are freed on error and not put on the ring. We may, however, be in a situation where we're freeing the last skb of a batch, and there is a doorbell ring pending because of xmit_more() being true earlier. Make sure we ring the door bell in such situations. Since errors are rare don't pay attention to xmit_more() and just always flush the pending frames. The busy case should be safe to be left alone because it can only happen if start_xmit races with completions and they both enable the queue. In that case the kick can't be pending. Noticed while reading the code. Fixes: 4d172f21cefe ("bnxt_en: Implement xmit_more.") Reviewed-by: Michael Chan Reviewed-by: Edwin Peer Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 39 +++++++++++++++-------- drivers/net/ethernet/broadcom/bnxt/bnxt.h | 1 + 2 files changed, 27 insertions(+), 13 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index 17ee5c436069..ea67c8c07a8b 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -69,7 +69,8 @@ #include "bnxt_debugfs.h" #define BNXT_TX_TIMEOUT (5 * HZ) -#define BNXT_DEF_MSG_ENABLE (NETIF_MSG_DRV | NETIF_MSG_HW) +#define BNXT_DEF_MSG_ENABLE (NETIF_MSG_DRV | NETIF_MSG_HW | \ + NETIF_MSG_TX_ERR) MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Broadcom BCM573xx network driver"); @@ -362,6 +363,13 @@ static u16 bnxt_xmit_get_cfa_action(struct sk_buff *skb) return md_dst->u.port_info.port_id; } +static void bnxt_txr_db_kick(struct bnxt *bp, struct bnxt_tx_ring_info *txr, + u16 prod) +{ + bnxt_db_write(bp, &txr->tx_db, prod); + txr->kick_pending = 0; +} + static bool bnxt_txr_netif_try_stop_queue(struct bnxt *bp, struct bnxt_tx_ring_info *txr, struct netdev_queue *txq) @@ -410,6 +418,10 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev) free_size = bnxt_tx_avail(bp, txr); if (unlikely(free_size < skb_shinfo(skb)->nr_frags + 2)) { + /* We must have raced with NAPI cleanup */ + if (net_ratelimit() && txr->kick_pending) + netif_warn(bp, tx_err, dev, + "bnxt: ring busy w/ flush pending!\n"); if (bnxt_txr_netif_try_stop_queue(bp, txr, txq)) return NETDEV_TX_BUSY; } @@ -518,21 +530,16 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev) normal_tx: if (length < BNXT_MIN_PKT_SIZE) { pad = BNXT_MIN_PKT_SIZE - length; - if (skb_pad(skb, pad)) { + if (skb_pad(skb, pad)) /* SKB already freed. */ - tx_buf->skb = NULL; - return NETDEV_TX_OK; - } + goto tx_kick_pending; length = BNXT_MIN_PKT_SIZE; } mapping = dma_map_single(&pdev->dev, skb->data, len, DMA_TO_DEVICE); - if (unlikely(dma_mapping_error(&pdev->dev, mapping))) { - dev_kfree_skb_any(skb); - tx_buf->skb = NULL; - return NETDEV_TX_OK; - } + if (unlikely(dma_mapping_error(&pdev->dev, mapping))) + goto tx_free; dma_unmap_addr_set(tx_buf, mapping, mapping); flags = (len << TX_BD_LEN_SHIFT) | TX_BD_TYPE_LONG_TX_BD | @@ -617,13 +624,15 @@ normal_tx: txr->tx_prod = prod; if (!netdev_xmit_more() || netif_xmit_stopped(txq)) - bnxt_db_write(bp, &txr->tx_db, prod); + bnxt_txr_db_kick(bp, txr, prod); + else + txr->kick_pending = 1; tx_done: if (unlikely(bnxt_tx_avail(bp, txr) <= MAX_SKB_FRAGS + 1)) { if (netdev_xmit_more() && !tx_buf->is_push) - bnxt_db_write(bp, &txr->tx_db, prod); + bnxt_txr_db_kick(bp, txr, prod); bnxt_txr_netif_try_stop_queue(bp, txr, txq); } @@ -635,7 +644,6 @@ tx_dma_error: /* start back at beginning and unmap skb */ prod = txr->tx_prod; tx_buf = &txr->tx_buf_ring[prod]; - tx_buf->skb = NULL; dma_unmap_single(&pdev->dev, dma_unmap_addr(tx_buf, mapping), skb_headlen(skb), PCI_DMA_TODEVICE); prod = NEXT_TX(prod); @@ -649,7 +657,12 @@ tx_dma_error: PCI_DMA_TODEVICE); } +tx_free: dev_kfree_skb_any(skb); +tx_kick_pending: + if (txr->kick_pending) + bnxt_txr_db_kick(bp, txr, txr->tx_prod); + txr->tx_buf_ring[txr->tx_prod].skb = NULL; return NETDEV_TX_OK; } diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h index 30e47ea343f9..e2f38aaa474b 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h @@ -783,6 +783,7 @@ struct bnxt_tx_ring_info { u16 tx_prod; u16 tx_cons; u16 txq_index; + u8 kick_pending; struct bnxt_db_info tx_db; struct tx_bd *tx_desc_ring[MAX_TX_PAGES]; -- 2.30.2