From patchwork Thu Jan 9 13:36:27 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Schmidt X-Patchwork-Id: 308804 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 6EE582C00AC for ; Fri, 10 Jan 2014 00:36:37 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754167AbaAINge (ORCPT ); Thu, 9 Jan 2014 08:36:34 -0500 Received: from mx1.redhat.com ([209.132.183.28]:10694 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751321AbaAINgc (ORCPT ); Thu, 9 Jan 2014 08:36:32 -0500 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s09DaUH9019337 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 9 Jan 2014 08:36:30 -0500 Received: from hp.brq.redhat.com (dhcp-27-43.brq.redhat.com [10.34.27.43]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id s09DaS3F018155; Thu, 9 Jan 2014 08:36:28 -0500 From: Michal Schmidt To: netdev@vger.kernel.org Cc: Ariel Elior , Yuval Mintz , Dmitry Kravkov , David Miller Subject: [PATCH net] bnx2x: fix DMA unmapping of TSO split BDs Date: Thu, 9 Jan 2014 14:36:27 +0100 Message-Id: <1389274587-6097-1-git-send-email-mschmidt@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org bnx2x triggers warnings with CONFIG_DMA_API_DEBUG=y: WARNING: CPU: 0 PID: 2253 at lib/dma-debug.c:887 check_unmap+0xf8/0x920() bnx2x 0000:28:00.0: DMA-API: device driver frees DMA memory with different size [device address=0x00000000da2b389e] [map size=1490 bytes] [unmap size=66 bytes] The reason is that bnx2x splits a TSO BD into two BDs (headers + data) using one DMA mapping for both, but it uses only the length of the first BD when unmapping. This patch fixes the bug by unmapping the whole length of the two BDs. Signed-off-by: Michal Schmidt Reviewed-by: Eric Dumazet Acked-by: Dmitry Kravkov --- drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c index ec96130..6b2704f 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c @@ -160,6 +160,7 @@ static u16 bnx2x_free_tx_pkt(struct bnx2x *bp, struct bnx2x_fp_txdata *txdata, struct sk_buff *skb = tx_buf->skb; u16 bd_idx = TX_BD(tx_buf->first_bd), new_cons; int nbd; + u16 split_bd_len = 0; /* prefetch skb end pointer to speedup dev_kfree_skb() */ prefetch(&skb->end); @@ -167,10 +168,7 @@ static u16 bnx2x_free_tx_pkt(struct bnx2x *bp, struct bnx2x_fp_txdata *txdata, DP(NETIF_MSG_TX_DONE, "fp[%d]: pkt_idx %d buff @(%p)->skb %p\n", txdata->txq_index, idx, tx_buf, skb); - /* unmap first bd */ tx_start_bd = &txdata->tx_desc_ring[bd_idx].start_bd; - dma_unmap_single(&bp->pdev->dev, BD_UNMAP_ADDR(tx_start_bd), - BD_UNMAP_LEN(tx_start_bd), DMA_TO_DEVICE); nbd = le16_to_cpu(tx_start_bd->nbd) - 1; #ifdef BNX2X_STOP_ON_ERROR @@ -188,12 +186,19 @@ static u16 bnx2x_free_tx_pkt(struct bnx2x *bp, struct bnx2x_fp_txdata *txdata, --nbd; bd_idx = TX_BD(NEXT_TX_IDX(bd_idx)); - /* ...and the TSO split header bd since they have no mapping */ + /* TSO headers+data bds share a common mapping. See bnx2x_tx_split() */ if (tx_buf->flags & BNX2X_TSO_SPLIT_BD) { + tx_data_bd = &txdata->tx_desc_ring[bd_idx].reg_bd; + split_bd_len = BD_UNMAP_LEN(tx_data_bd); --nbd; bd_idx = TX_BD(NEXT_TX_IDX(bd_idx)); } + /* unmap first bd */ + dma_unmap_single(&bp->pdev->dev, BD_UNMAP_ADDR(tx_start_bd), + BD_UNMAP_LEN(tx_start_bd) + split_bd_len, + DMA_TO_DEVICE); + /* now free frags */ while (nbd > 0) {