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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 3E431C0650F for ; Tue, 30 Jul 2019 15:07:11 +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 12B9F206B8 for ; Tue, 30 Jul 2019 15:07:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="M4BLUVsG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 12B9F206B8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=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.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject: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=RZtsR9hB8t+FqDbKUijaxvkg9T8UZ63a8v8Pa6B1nsU=; b=M4BLUVsG12DGOC Zm3RdMLWJmv4g7oXQgMrGM6pjodYKuB6DC41FCZ8mcmacFk5/b9Ooe37umn4Z28lb+qY4j3JhfDDG gPK+RJGr0Ww8lKHTZIj+l5HglUASanUjae+OQXoh/WPG2QPpTpoyApSaMy+GN1f2hUqC+KSQPxoHv IDabuknnEISP+iF+Uk3TAbw0acrlagAdnSpS5VsVKMefPbjmrkvPBe1YWTzA0TJvtCmb7a+bCQmQd IdBu3Znf1qe68T1njTjX2w3KoUGEXEcvDbPqbWM88RO68RWGjPI6Qc9/+GTRYteEcGe9NDKXMZZQq Vy94RCknxtHAbfyWLp+w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hsTiH-00014m-Gv; Tue, 30 Jul 2019 15:06:53 +0000 Received: from hch by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1hsTho-0000n1-Sp; Tue, 30 Jul 2019 15:06:25 +0000 Date: Tue, 30 Jul 2019 08:06:24 -0700 From: Christoph Hellwig To: Robin Murphy Subject: Re: [PATCH] iommu/dma: Handle MSI mappings separately Message-ID: <20190730150624.GA27573@infradead.org> References: <2b2595de703c60a772ebcffe248d0cf036143e6a.1564414114.git.robin.murphy@arm.com> <20190730062843.GA1400@infradead.org> <90566814-ed36-2eb9-49e2-98a4a949c9f6@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <90566814-ed36-2eb9-49e2-98a4a949c9f6@arm.com> User-Agent: Mutt/1.11.4 (2019-03-13) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: maz@kernel.org, joro@8bytes.org, Christoph Hellwig , iommu@lists.linux-foundation.org, Andre Przywara , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Jul 30, 2019 at 11:43:25AM +0100, Robin Murphy wrote: > > Hmm. I remember proposing this patch and you didn't like it because > > we could also have msis for a !IOMMU_DMA_IOVA_COOKIE cookie type. > > Or did we talk past each other? > > Do you have a pointer? That sparks the vaguest of memories, but I can't seem > to turn anything up in my inbox. If that was my objection, though, it sounds > like your patch was probably trying to go a step or two further than this > one. I can't find anything either. This must have been a git tree I passed around to you before posting it. > > Note that if this change turns out to be valid we should also > > clean up the iommu_dma_free_iova() side. > > We're not touching the iommu_dma_{alloc,free}_iova() path here; those are > designed to cope with both types of cookie, and I think that's a reasonable > abstraction to keep. This is just getting rid of the asymmetry - and now bug > - caused by trying to keep the MSI page flow going through a special case in > __iommu_dma_map() despite that having evolved into a more specific DMA > domain fastpath (there's no corresponding unmap special case since MSI > mappings just persist and get recycled until the domain is destroyed). Ok, that might have been the issue with my earlier patch.. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel