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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 B3517C47404 for ; Thu, 10 Oct 2019 01:26:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F8BF20B7C for ; Thu, 10 Oct 2019 01:26:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732596AbfJJB0d (ORCPT ); Wed, 9 Oct 2019 21:26:33 -0400 Received: from mga02.intel.com ([134.134.136.20]:11087 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731134AbfJJB0d (ORCPT ); Wed, 9 Oct 2019 21:26:33 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Oct 2019 18:26:32 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.67,278,1566889200"; d="scan'208";a="218862439" Received: from allen-box.sh.intel.com (HELO [10.239.159.136]) ([10.239.159.136]) by fmsmga004.fm.intel.com with ESMTP; 09 Oct 2019 18:26:30 -0700 Cc: baolu.lu@linux.intel.com, Arvind Sankar , linux-kernel@vger.kernel.org Subject: Re: [PATCH] iommu/vt-d: Return the correct dma mask when we are bypassing the IOMMU To: Christoph Hellwig References: <20191008143357.GA599223@rani.riverdale.lan> <76d680ab-a454-4a69-597a-c0edbfc5014b@linux.intel.com> <20191009065115.GB30157@lst.de> From: Lu Baolu Message-ID: Date: Thu, 10 Oct 2019 09:24:15 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20191009065115.GB30157@lst.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Christoph, On 10/9/19 2:51 PM, Christoph Hellwig wrote: > On Wed, Oct 09, 2019 at 10:45:15AM +0800, Lu Baolu wrote: >> Do you mind explaining why we always return 32 bit here? > > See the comment in dma_get_required_mask(). > Got it. Thank you. Best regards, Baolu