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=-7.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 E5790C2BA17 for ; Mon, 6 Apr 2020 17:17:15 +0000 (UTC) Received: from fraxinus.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 98F8B249C0 for ; Mon, 6 Apr 2020 17:17:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 98F8B249C0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 72DFD8650A; Mon, 6 Apr 2020 17:17:15 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id NIc298pJ4Qhf; Mon, 6 Apr 2020 17:17:14 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id E55E38539A; Mon, 6 Apr 2020 17:17:14 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id D5EE1C1AE2; Mon, 6 Apr 2020 17:17:14 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id F16A1C0177 for ; Mon, 6 Apr 2020 17:17:13 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id DAD29885B9 for ; Mon, 6 Apr 2020 17:17:13 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id A+cdvL3VngQI for ; Mon, 6 Apr 2020 17:17:11 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by hemlock.osuosl.org (Postfix) with ESMTPS id A8C888858D for ; Mon, 6 Apr 2020 17:17:11 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 0319068BEB; Mon, 6 Apr 2020 19:17:06 +0200 (CEST) Date: Mon, 6 Apr 2020 19:17:06 +0200 From: Christoph Hellwig To: Alexey Kardashevskiy Subject: Re: [PATCH 1/2] dma-mapping: add a dma_ops_bypass flag to struct device Message-ID: <20200406171706.GA3231@lst.de> References: <87sghz2ibh.fsf@linux.ibm.com> <20200323172256.GB31269@lst.de> <20200324075402.GJ23447@lst.de> <41975da3-3a4a-fc3c-2b90-8d607cf220e6@ozlabs.ru> <20200325083740.GC21605@lst.de> <213b0c7d-f908-b4f4-466d-6240c3622cd6@ozlabs.ru> <20200406115016.GA10941@lst.de> <348046e7-7a38-62d6-4df0-e4a537b98926@ozlabs.ru> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <348046e7-7a38-62d6-4df0-e4a537b98926@ozlabs.ru> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: Greg Kroah-Hartman , Robin Murphy , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Michael Ellerman , "Aneesh Kumar K.V" , linuxppc-dev@lists.ozlabs.org, Christoph Hellwig 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 Mon, Apr 06, 2020 at 11:25:09PM +1000, Alexey Kardashevskiy wrote: > >> Do you see any serious problem with this approach? Thanks! > > > > Do you have a link to the whole branch? The github UI is unfortunately > > unusable for that (or I'm missing something). > > The UI shows the branch but since I rebased and forcepushed it, it does > not. Here is the current one with: > > https://github.com/aik/linux/commits/dma-bypass.3 Ok, so we use the core bypass without persistent memory, and then have another bypass mode on top. Not great, but I can't think of anything better. Note that your checks for the map_sg case aren't very efficient - for one it would make sense to calculate the limit only once, but also it would make sense to reuse the calculted diecect mapping addresses instead of doing another pass later on in the dma-direct code. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu