From patchwork Tue Nov 24 17:26:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Falcon X-Patchwork-Id: 331902 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham 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 067D9C64E7A for ; Tue, 24 Nov 2020 17:26:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A9C692087C for ; Tue, 24 Nov 2020 17:26:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="Yf8LMoBQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390827AbgKXR0i (ORCPT ); Tue, 24 Nov 2020 12:26:38 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:44172 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2390777AbgKXR0h (ORCPT ); Tue, 24 Nov 2020 12:26:37 -0500 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 0AOH1u0s057647; Tue, 24 Nov 2020 12:26:32 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=pp1; bh=jgPr9DpKUXRYYRM7d5HIgT94yT1HbuulKGlIcP83Pcg=; b=Yf8LMoBQ10UDYOty31iYeBprYIFBv0EI4Cf2weJQphBNGlejlKbYu3lEdkixwG68Hnmh KqY1tWG8aaUe3+0aNHWbiC8eBcV2Zp6oxInI0cSeu/HbstJJKdIesGtjXnq2W2hEQGFP qJLIyqRmiQSEd18uJyx7p119W2oQCPlM2Cdaj+atMCPvvOxbhoec8aDnfl9uYKYwgTya juoO0n+goYdOoWHXJQSaDvpx5Jwh8TvlgNQsRrZL3mR2LxmpbGuUpGT5//H9eWZEwcT7 Rz7rLBCeG+VA6t80j4ancOzvtlPpJM3gCc20PDUx+c7vn07Szoj7IgbfFQJyd2/qHrwn jg== Received: from ppma02dal.us.ibm.com (a.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.10]) by mx0b-001b2d01.pphosted.com with ESMTP id 3513uwe7p9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 24 Nov 2020 12:26:32 -0500 Received: from pps.filterd (ppma02dal.us.ibm.com [127.0.0.1]) by ppma02dal.us.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 0AOHN7uN022134; Tue, 24 Nov 2020 17:26:31 GMT Received: from b03cxnp07028.gho.boulder.ibm.com (b03cxnp07028.gho.boulder.ibm.com [9.17.130.15]) by ppma02dal.us.ibm.com with ESMTP id 34xth9yb30-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 24 Nov 2020 17:26:31 +0000 Received: from b03ledav003.gho.boulder.ibm.com (b03ledav003.gho.boulder.ibm.com [9.17.130.234]) by b03cxnp07028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 0AOHQUn955181624 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 24 Nov 2020 17:26:30 GMT Received: from b03ledav003.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 178B36A057; Tue, 24 Nov 2020 17:26:30 +0000 (GMT) Received: from b03ledav003.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id ECF276A047; Tue, 24 Nov 2020 17:26:27 +0000 (GMT) Received: from oc7186267434.ibm.com (unknown [9.160.17.166]) by b03ledav003.gho.boulder.ibm.com (Postfix) with ESMTP; Tue, 24 Nov 2020 17:26:27 +0000 (GMT) From: Thomas Falcon To: netdev@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org, cforno12@linux.ibm.com, ljp@linux.vnet.ibm.com, ricklind@linux.ibm.com, dnbanerg@us.ibm.com, drt@linux.vnet.ibm.com, brking@linux.vnet.ibm.com, sukadev@linux.vnet.ibm.com, tlfalcon@linux.ibm.com Subject: [PATCH net 1/2] ibmvnic: Ensure that SCRQ entry reads are correctly ordered Date: Tue, 24 Nov 2020 11:26:15 -0600 Message-Id: <1606238776-30259-2-git-send-email-tlfalcon@linux.ibm.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1606238776-30259-1-git-send-email-tlfalcon@linux.ibm.com> References: <1606238776-30259-1-git-send-email-tlfalcon@linux.ibm.com> X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.312, 18.0.737 definitions=2020-11-24_04:2020-11-24,2020-11-24 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=1 priorityscore=1501 lowpriorityscore=0 bulkscore=0 spamscore=0 phishscore=0 mlxscore=0 mlxlogscore=999 clxscore=1015 impostorscore=0 adultscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011240103 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Ensure that received Subordinate Command-Response Queue (SCRQ) entries are properly read in order by the driver. These queues are used in the ibmvnic device to process RX buffer and TX completion descriptors. dma_rmb barriers have been added after checking for a pending descriptor to ensure the correct descriptor entry is checked and after reading the SCRQ descriptor to ensure the entire descriptor is read before processing. Fixes: 032c5e828 ("Driver for IBM System i/p VNIC protocol") Signed-off-by: Thomas Falcon --- drivers/net/ethernet/ibm/ibmvnic.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 2aa40b2..489ed5e 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -2403,6 +2403,8 @@ static int ibmvnic_poll(struct napi_struct *napi, int budget) if (!pending_scrq(adapter, adapter->rx_scrq[scrq_num])) break; + /* ensure that we do not prematurely exit the polling loop */ + dma_rmb(); next = ibmvnic_next_scrq(adapter, adapter->rx_scrq[scrq_num]); rx_buff = (struct ibmvnic_rx_buff *)be64_to_cpu(next-> @@ -3098,6 +3100,9 @@ static int ibmvnic_complete_tx(struct ibmvnic_adapter *adapter, unsigned int pool = scrq->pool_index; int num_entries = 0; + /* ensure that the correct descriptor entry is read */ + dma_rmb(); + next = ibmvnic_next_scrq(adapter, scrq); for (i = 0; i < next->tx_comp.num_comps; i++) { if (next->tx_comp.rcs[i]) { @@ -3498,6 +3503,9 @@ static union sub_crq *ibmvnic_next_scrq(struct ibmvnic_adapter *adapter, } spin_unlock_irqrestore(&scrq->lock, flags); + /* ensure that the entire SCRQ descriptor is read */ + dma_rmb(); + return entry; }