Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935855AbaBDXHA (ORCPT ); Tue, 4 Feb 2014 18:07:00 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:55987 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932779AbaBDVAn (ORCPT ); Tue, 4 Feb 2014 16:00:43 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michal Schmidt , Eric Dumazet , Dmitry Kravkov , "David S. Miller" Subject: [PATCH 3.4 28/37] bnx2x: fix DMA unmapping of TSO split BDs Date: Tue, 4 Feb 2014 13:01:04 -0800 Message-Id: <20140204210056.801785530@linuxfoundation.org> X-Mailer: git-send-email 1.8.5.1.163.gd7aced9 In-Reply-To: <20140204210055.992134150@linuxfoundation.org> References: <20140204210055.992134150@linuxfoundation.org> User-Agent: quilt/0.61-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michal Schmidt [ Upstream commit 95e92fd40c967c363ad66b2fd1ce4dcd68132e54 ] 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c @@ -71,6 +71,7 @@ static u16 bnx2x_free_tx_pkt(struct bnx2 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); @@ -78,10 +79,7 @@ static u16 bnx2x_free_tx_pkt(struct bnx2 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; @@ -100,12 +98,19 @@ static u16 bnx2x_free_tx_pkt(struct bnx2 --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) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/