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=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT 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 D4CB0C04AB6 for ; Fri, 31 May 2019 17:46:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9F6F726D57 for ; Fri, 31 May 2019 17:46:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="OcvvfIQW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726917AbfEaRqe (ORCPT ); Fri, 31 May 2019 13:46:34 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:38982 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725934AbfEaRqd (ORCPT ); Fri, 31 May 2019 13:46:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=sw59L5eilDcyLax1cbN/oovEq+2iPQ87MItZHDnliB8=; b=OcvvfIQWRmhZciRaxx8x6dnj7 P9/7pUyMmERrI8OtitGh0I1lua9/boy6cCyy8Ladvj3L+81QcfLZA3/MpAXnqBYWumQ7OwxjHJzyW dYcTgnoubni9ek4e+t2NdyFiporyzaIlnP+Sqtx7nVnm4QpWkErFIuu3c//DEmHtOceqwmRR+TleY 5xdn+M5QVBRJydb756QKcrm2LYNcpari+BbBMzfF1a1qnRAOkMBtY1ouzqY7uu11IRMQ992tj+IwH kTGIKLKzrT0G7yIOK0n8A8VlEo0R3dSDvfZe6tdSfdipO9HLYIyRazJqOFjrnnt5KR1OHdtFysfhd 5WgaU7K6g==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1hWlbq-00022N-4T; Fri, 31 May 2019 17:46:30 +0000 Date: Fri, 31 May 2019 10:46:30 -0700 From: Christoph Hellwig To: Robin Murphy Cc: Christoph Hellwig , David Miller , madalin.bucur@nxp.com, netdev@vger.kernel.org, roy.pledge@nxp.com, linux-kernel@vger.kernel.org, leoyang.li@nxp.com, Joakim.Tjernlund@infinera.com, iommu@lists.linux-foundation.org, camelia.groza@nxp.com, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v3 0/6] Prerequisites for NXP LS104xA SMMU enablement Message-ID: <20190531174629.GA6298@infradead.org> References: <20190530141951.6704-1-laurentiu.tudor@nxp.com> <20190530.150844.1826796344374758568.davem@davemloft.net> <20190531163350.GB8708@infradead.org> <37406608-df48-c7a0-6975-4b4ad408ba36@arm.com> <20190531170804.GA12211@infradead.org> <1b81c168-f5e0-f86a-f90e-22e8c3f2a602@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1b81c168-f5e0-f86a-f90e-22e8c3f2a602@arm.com> User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 31, 2019 at 06:45:00PM +0100, Robin Murphy wrote: > Bleh, I'm certainly not keen on formalising any kind of > dma_to_phys()/dma_to_virt() interface for this. Or are you just proposing > something like dma_unmap_sorry_sir_the_dog_ate_my_homework() for drivers > which have 'lost' the original VA they mapped? Yes, I guess we need that in some form. I've heard a report the IBM emca ethernet driver has the same issue, and any SOC with it this totally blows up dma-debug as they just never properly unmap.