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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 4469DC55178 for ; Fri, 30 Oct 2020 12:29:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F041A20731 for ; Fri, 30 Oct 2020 12:29:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725939AbgJ3MUW (ORCPT ); Fri, 30 Oct 2020 08:20:22 -0400 Received: from mga01.intel.com ([192.55.52.88]:51972 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726072AbgJ3MUB (ORCPT ); Fri, 30 Oct 2020 08:20:01 -0400 IronPort-SDR: VdvqhYGDw3pAe8RaPnVe+OTzeOtEfPWqWvnMbAThCp4uc4AqjCmDtk6h6oaF1MrFTStl3BE+dc s+w9N3C2X3qw== X-IronPort-AV: E=McAfee;i="6000,8403,9789"; a="186403325" X-IronPort-AV: E=Sophos;i="5.77,433,1596524400"; d="scan'208";a="186403325" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Oct 2020 05:20:01 -0700 IronPort-SDR: AAGYOfGaWyPm0BaBIcy7C0IGQEEmEtL1ioyXADbLWz/QZEVzBipGynyUUgSes9i3S9SgxuAmjs wGZ/8cJWotAA== X-IronPort-AV: E=Sophos;i="5.77,433,1596524400"; d="scan'208";a="537048236" Received: from ddalessa-mobl.amr.corp.intel.com (HELO [10.254.203.232]) ([10.254.203.232]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Oct 2020 05:19:59 -0700 Subject: Re: [PATCH] RDMA: Fix software RDMA drivers for dma mapping error To: Jason Gunthorpe , Parav Pandit Cc: mike.marciniszyn@cornelisnetworks.com, dledford@redhat.com, yanjunz@nvidia.com, bmt@zurich.ibm.com, linux-rdma@vger.kernel.org, hch@lst.de, syzbot+34dc2fea3478e659af01@syzkaller.appspotmail.com References: <20201030093803.278830-1-parav@nvidia.com> <20201030121731.GA36674@ziepe.ca> From: Dennis Dalessandro Message-ID: <71c2013a-e9af-470c-9fae-30fc0cf78ee3@cornelisnetworks.com> Date: Fri, 30 Oct 2020 08:19:56 -0400 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.1 MIME-Version: 1.0 In-Reply-To: <20201030121731.GA36674@ziepe.ca> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On 10/30/2020 8:17 AM, Jason Gunthorpe wrote: > On Fri, Oct 30, 2020 at 11:38:03AM +0200, Parav Pandit wrote: >> @@ -1140,7 +1141,10 @@ int rxe_register_device(struct rxe_dev *rxe, const char *ibdev_name) >> rxe->ndev->dev_addr); >> dev->dev.dma_parms = &rxe->dma_parms; >> dma_set_max_seg_size(&dev->dev, UINT_MAX); >> - dma_set_coherent_mask(&dev->dev, dma_get_required_mask(&dev->dev)); >> + dma_mask = IS_ENABLED(CONFIG_64BIT) ? DMA_BIT_MASK(64) : DMA_BIT_MASK(32); >> + err = dma_coerce_mask_and_coherent(&dev->dev, dma_mask); > > Since this mask doesn't actually do anything, what is the reason to > have the 64/32? Technically there isn't. We are already dependent on 64bit config anyway. Mike M just brought this up in a side bar conversation actually. -Denny