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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 04C4DC282DC for ; Mon, 3 Jun 2019 00:42:44 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B0DDA27A43 for ; Mon, 3 Jun 2019 00:42:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B0DDA27A43 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 6923FB7D; Mon, 3 Jun 2019 00:42:43 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 2E071B5F for ; Mon, 3 Jun 2019 00:42:42 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 5F20983A for ; Mon, 3 Jun 2019 00:42:40 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Jun 2019 17:42:39 -0700 X-ExtLoop1: 1 Received: from allen-box.sh.intel.com (HELO [10.239.159.136]) ([10.239.159.136]) by orsmga004.jf.intel.com with ESMTP; 02 Jun 2019 17:42:35 -0700 Subject: Re: [PATCH v4 10/15] iommu/vt-d: Probe DMA-capable ACPI name space devices To: Christoph Hellwig References: <20190525054136.27810-1-baolu.lu@linux.intel.com> <20190525054136.27810-11-baolu.lu@linux.intel.com> <20190529061626.GA26055@infradead.org> From: Lu Baolu Message-ID: <23d9d04c-c3fd-716e-dd66-eb5119aad4f9@linux.intel.com> Date: Mon, 3 Jun 2019 08:35:39 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190529061626.GA26055@infradead.org> Content-Language: en-US Cc: kevin.tian@intel.com, ashok.raj@intel.com, dima@arista.com, tmurphy@arista.com, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, jacob.jun.pan@intel.com, David Woodhouse X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org Hi, On 5/29/19 2:16 PM, Christoph Hellwig wrote: > On Sat, May 25, 2019 at 01:41:31PM +0800, Lu Baolu wrote: >> Some platforms may support ACPI name-space enumerated devices >> that are capable of generating DMA requests. Platforms which >> support DMA remapping explicitly declares any such DMA-capable >> ACPI name-space devices in the platform through ACPI Name-space >> Device Declaration (ANDD) structure and enumerate them through >> the Device Scope of the appropriate remapping hardware unit. >> >> Signed-off-by: Lu Baolu > > Isn't this something that should be handled through the IOMMU API so > that it covers other IOMMU types as well? > > How does this scheme compare to the one implemented in > drivers/acpi/arm64/iort.c? > This part of code was added to be compatible with the past. Yes. I've ever thought about this. But these devices sit on the acpi bus together with other devices which are not DMA-capable. And on some platforms these devices exist on the pci bus as well. Best regards, Baolu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu