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=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,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 3F376C07E94 for ; Fri, 4 Jun 2021 15:44:56 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 E1B1C613D8 for ; Fri, 4 Jun 2021 15:44:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E1B1C613D8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-rockchip-bounces+linux-rockchip=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=UswbPDm5iAuZ8WseRSTmtlRt4P58pvFmtCxQnBAz/Jg=; b=Eut/7LH00+2UoB UlNInlmVR2KgSJ3ae2opKpqzlPzhncr9K7Iv9Wpy1IcBD8/mQDNKIzMDskWKga+QG56EWq0kTcJuZ 1IByCCkrJp45OfLJjMOJXHoNhib2z8qOy4r/nUtYxmLZ032CaklZvvXqGxgTR5ncrmy+Yi2IRXgbO +tkeuNKsAEnsaeSkS2w6X3Nojy5gCi8/XGPER6JLVEXA3V4un92oJ4YcA/n2eiabiu0VTGVsOlzNV Zz0WBsTSu6fvAb9ntPuWFX3PAap5kS2+jX+ptWnXjfNB43SKhtm3Q6tSom1One3SCRXHlH2mht8EQ jTuRZ/k1gISt7+Cz6EUw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lpC0B-00EDwR-JP; Fri, 04 Jun 2021 15:44:51 +0000 Received: from 8bytes.org ([81.169.241.247] helo=theia.8bytes.org) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lpC09-00EDtx-7c for linux-rockchip@lists.infradead.org; Fri, 04 Jun 2021 15:44:50 +0000 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 Cc: "xxm@rock-chips.com" , hch , will , iommu , linux-rockchip 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> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210604_084449_466048_9D171E58 X-CRM114-Status: GOOD ( 13.00 ) X-BeenThere: linux-rockchip@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Upstream kernel work for Rockchip platforms List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+linux-rockchip=archiver.kernel.org@lists.infradead.org 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 _______________________________________________ Linux-rockchip mailing list Linux-rockchip@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-rockchip