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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 518E6C433EF for ; Thu, 6 Jan 2022 03:48:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231406AbiAFDsh (ORCPT ); Wed, 5 Jan 2022 22:48:37 -0500 Received: from mga02.intel.com ([134.134.136.20]:7494 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230498AbiAFDsg (ORCPT ); Wed, 5 Jan 2022 22:48:36 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1641440916; x=1672976916; h=cc:subject:to:references:from:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=s88NpyScOH/XjHqT1y7xLL0UmtzfW9rw5bZNtIuacDQ=; b=lOxOwoIQ15KuMbql7N6AA6wUn/8h0QE56SMTMYQN0iObfPbvzVXE3RsL tdpk8YE82tlUQIlxqgpof0+P4yxfDo5zk0kOXtu0c7KzyMAMz9l4u2kiC XW7hQ8104P1HPAekaxqFbuOIus56Fa7imOVWHWxYxurRZluM3Lh2onOi4 0DfsSEKuXCLKLMoQzN3saDKhAxaLOS1wKGCah2cnHSYtSklqf8NXk+SoN ZVxq3z5dSByuNjmLFZx+0jOMNrwmvVzukrciWU0+lcTl16u0bEwcADI7K xqCy4qYS//0pyFgvBNbPY2mDm3fE009kLCTvM0R3elDAFmXxfcNd5DJiA A==; X-IronPort-AV: E=McAfee;i="6200,9189,10217"; a="229907951" X-IronPort-AV: E=Sophos;i="5.88,265,1635231600"; d="scan'208";a="229907951" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jan 2022 19:48:35 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,265,1635231600"; d="scan'208";a="526815184" Received: from allen-box.sh.intel.com (HELO [10.239.159.118]) ([10.239.159.118]) by orsmga008.jf.intel.com with ESMTP; 05 Jan 2022 19:48:29 -0800 Cc: baolu.lu@linux.intel.com, Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Kevin Tian , Ashok Raj , Will Deacon , Robin Murphy , Dan Williams , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , Stuart Yoder , Laurentiu Tudor , Thierry Reding , David Airlie , Daniel Vetter , Jonathan Hunter , Li Yang , Dmitry Osipenko , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 01/14] iommu: Add dma ownership management interfaces To: Bjorn Helgaas , Christoph Hellwig References: <20220104164100.GA101735@bhelgaas> From: Lu Baolu Message-ID: <8e83da6c-7ae4-b855-ccf0-148d2babfcce@linux.intel.com> Date: Thu, 6 Jan 2022 11:47:50 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: <20220104164100.GA101735@bhelgaas> 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-kernel@vger.kernel.org On 1/5/22 12:41 AM, Bjorn Helgaas wrote: >>> Devices under kernel drivers control must call iommu_device_use_dma_api() >>> before driver probes. The driver binding process must be aborted if it >>> returns failure. > "Devices" don't call functions. Drivers do, or in this case, it looks > like the bus DMA code (platform, amba, fsl, pci, etc). > > These functions are EXPORT_SYMBOL_GPL(), but it looks like all the > callers are built-in, so maybe the export is unnecessary? Yes. If all callers are built-in, we can remove this export. > > You use "iommu"/"IOMMU" and "dma"/"DMA" interchangeably above. Would > be easier to read if you picked one. > I should cleanup all these. I also realized that I forgot to cleanup some typos you pointed out in v4: https://lore.kernel.org/linux-iommu/20211229211626.GA1701512@bhelgaas/ Sorry about it. I will take care of all these in the next version. Best regards, baolu