From patchwork Mon May 14 12:14:49 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: hpreg@vmware.com X-Patchwork-Id: 912901 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=vmware.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 40l058449Qz9s08 for ; Mon, 14 May 2018 22:15:08 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752897AbeENMOz (ORCPT ); Mon, 14 May 2018 08:14:55 -0400 Received: from ex13-edg-ou-002.vmware.com ([208.91.0.190]:12801 "EHLO EX13-EDG-OU-002.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752153AbeENMOy (ORCPT ); Mon, 14 May 2018 08:14:54 -0400 Received: from sc9-mailhost3.vmware.com (10.113.161.73) by EX13-EDG-OU-002.vmware.com (10.113.208.156) with Microsoft SMTP Server id 15.0.1156.6; Mon, 14 May 2018 05:14:52 -0700 Received: from bos2-arm-build.eng.vmware.com (bos2-arm-build.eng.vmware.com [10.118.233.19]) by sc9-mailhost3.vmware.com (Postfix) with SMTP id A8EF2404B3; Mon, 14 May 2018 05:14:52 -0700 (PDT) Received: by bos2-arm-build.eng.vmware.com (sSMTP sendmail emulation); Mon, 14 May 2018 08:14:52 -0400 From: To: CC: Regis Duchesne , Ronak Doshi , "VMware, Inc." , open list Subject: [PATCH net 2/2] vmxnet3: use DMA memory barriers where required Date: Mon, 14 May 2018 08:14:49 -0400 Message-ID: <1526300090-78546-1-git-send-email-hpreg@vmware.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Received-SPF: None (EX13-EDG-OU-002.vmware.com: hpreg@vmware.com does not designate permitted sender hosts) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The gen bits must be read first from (resp. written last to) DMA memory. The proper way to enforce this on Linux is to call dma_rmb() (resp. dma_wmb()). Signed-off-by: Regis Duchesne Acked-by: Ronak Doshi --- drivers/net/vmxnet3/vmxnet3_drv.c | 22 ++++++++++++++++++++++ drivers/net/vmxnet3/vmxnet3_int.h | 4 ++-- 2 files changed, 24 insertions(+), 2 deletions(-) diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c index ed58685..27a9bb8 100644 --- a/drivers/net/vmxnet3/vmxnet3_drv.c +++ b/drivers/net/vmxnet3/vmxnet3_drv.c @@ -369,6 +369,11 @@ vmxnet3_tq_tx_complete(struct vmxnet3_tx_queue *tq, gdesc = tq->comp_ring.base + tq->comp_ring.next2proc; while (VMXNET3_TCD_GET_GEN(&gdesc->tcd) == tq->comp_ring.gen) { + /* Prevent any &gdesc->tcd field from being (speculatively) + * read before (&gdesc->tcd)->gen is read. + */ + dma_rmb(); + completed += vmxnet3_unmap_pkt(VMXNET3_TCD_GET_TXIDX( &gdesc->tcd), tq, adapter->pdev, adapter); @@ -1103,6 +1108,11 @@ vmxnet3_tq_xmit(struct sk_buff *skb, struct vmxnet3_tx_queue *tq, gdesc->txd.tci = skb_vlan_tag_get(skb); } + /* Ensure that the write to (&gdesc->txd)->gen will be observed after + * all other writes to &gdesc->txd. + */ + dma_wmb(); + /* finally flips the GEN bit of the SOP desc. */ gdesc->dword[2] = cpu_to_le32(le32_to_cpu(gdesc->dword[2]) ^ VMXNET3_TXD_GEN); @@ -1298,6 +1308,12 @@ vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq, */ break; } + + /* Prevent any rcd field from being (speculatively) read before + * rcd->gen is read. + */ + dma_rmb(); + BUG_ON(rcd->rqID != rq->qid && rcd->rqID != rq->qid2 && rcd->rqID != rq->dataRingQid); idx = rcd->rxdIdx; @@ -1528,6 +1544,12 @@ vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq, ring->next2comp = idx; num_to_alloc = vmxnet3_cmd_ring_desc_avail(ring); ring = rq->rx_ring + ring_idx; + + /* Ensure that the writes to rxd->gen bits will be observed + * after all other writes to rxd objects. + */ + dma_wmb(); + while (num_to_alloc) { vmxnet3_getRxDesc(rxd, &ring->base[ring->next2fill].rxd, &rxCmdDesc); diff --git a/drivers/net/vmxnet3/vmxnet3_int.h b/drivers/net/vmxnet3/vmxnet3_int.h index b379bed..a2c554f 100644 --- a/drivers/net/vmxnet3/vmxnet3_int.h +++ b/drivers/net/vmxnet3/vmxnet3_int.h @@ -69,12 +69,12 @@ /* * Version numbers */ -#define VMXNET3_DRIVER_VERSION_STRING "1.4.15.0-k" +#define VMXNET3_DRIVER_VERSION_STRING "1.4.16.0-k" /* Each byte of this 32-bit integer encodes a version number in * VMXNET3_DRIVER_VERSION_STRING. */ -#define VMXNET3_DRIVER_VERSION_NUM 0x01040f00 +#define VMXNET3_DRIVER_VERSION_NUM 0x01041000 #if defined(CONFIG_PCI_MSI) /* RSS only makes sense if MSI-X is supported. */