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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 A71A6C47083 for ; Fri, 4 Jun 2021 15:44:56 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (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 502406101C for ; Fri, 4 Jun 2021 15:44:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 502406101C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 19E3C415B7; Fri, 4 Jun 2021 15:44:56 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id crzDkL6uY0xB; Fri, 4 Jun 2021 15:44:51 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp4.osuosl.org (Postfix) with ESMTP id 6437A415B3; Fri, 4 Jun 2021 15:44:51 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 3D935C000D; Fri, 4 Jun 2021 15:44:51 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [IPv6:2605:bc80:3010::138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 49F3DC0001 for ; Fri, 4 Jun 2021 15:44:49 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 214FD84326 for ; Fri, 4 Jun 2021 15:44:49 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id L4Mj9aeyChsR for ; Fri, 4 Jun 2021 15:44:48 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from theia.8bytes.org (8bytes.org [IPv6:2a01:238:4383:600:38bc:a715:4b6d:a889]) by smtp1.osuosl.org (Postfix) with ESMTPS id 84D68842A6 for ; Fri, 4 Jun 2021 15:44:48 +0000 (UTC) Received: by theia.8bytes.org (Postfix, from userid 1000) id 993B93A9; Fri, 4 Jun 2021 17:44:46 +0200 (CEST) Date: Fri, 4 Jun 2021 17:44:45 +0200 From: joro To: Robin Murphy Subject: Re: Different type iommus integrated in a SoC Message-ID: References: <2021052710373173260118@rock-chips.com> <5d7127d5-b73c-2002-1734-98aab2295c8e@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <5d7127d5-b73c-2002-1734-98aab2295c8e@arm.com> Cc: linux-rockchip , iommu , will , hch X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Thu, Jun 03, 2021 at 01:05:43PM +0100, Robin Murphy wrote: > Hooray! I've been forecasting this for years, but the cases we regularly hit > with internal FPGA prototyping (nor the secret unused MMU-400 I found on > RK3288) have never really been a strong enough argument to stand behind. > > Based on what I remember from looking into this a few years ago, converting > *most* of the API to per-device ops (now via dev->iommu) is trivial; the > main challenge will be getting the per-device data bootstrapped in > iommu_probe_device(), which would probably need to rely on the fwspec and/or > list of registered IOMMU instances. > > The other notable thing which will need to change is the domain allocation > interface, but in practice I think everyone who calls iommu_domain_alloc() > today is in fact doing so for a specific device, so I don't think it's as > big a problem as it might first appear. Yeah, I think for that we have to give up on the promise that a domain can be assigned to _any_ device. But this promise doesn't even hold true now when there are several IOMMU of the same type but with different feature sets in a system. So I happily review patches enabling the Multi-IOMMU SOCs :) Regards, Joerg _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu