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=-3.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 48061C4332E for ; Fri, 20 Mar 2020 14:19:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E01F20754 for ; Fri, 20 Mar 2020 14:19:11 +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="B6/zKn9h" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726951AbgCTOTK (ORCPT ); Fri, 20 Mar 2020 10:19:10 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:56638 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726666AbgCTOTJ (ORCPT ); Fri, 20 Mar 2020 10:19:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:In-Reply-To:References; bh=fP76rVZ78wXp8cMUTCCjVQv5iPeDciWQiuxMnftZdbU=; b=B6/zKn9hIGXiUR1+IFAOol+kv1 XjmHCPdWqbtmD9fPyqucY8V+g+o9OLOvI3t+vrDdb/DQOqyScEnQli0GsUE5QpHE3YjdPBKaRCK68 rQSN6kmN+N0Smxlwq+SoFYRFj3SxRcSTi1Yh+KaTdPyhzA+m1CzeAqONaNmB+4ZAaLWxYwgTBl+jb ILStHKt07ubvKmWQ63yuEZKU86Ihy8RxKbgZoXwxkIDn8QKjcBqMVb/ZK6RXAsYaxHRY42JJ2qj0L 6LlhF9zgzO3uCzN93uOom5TnQF6sMVJq6DscqerEEnHaIo7nFdfFl+Nips+DMKRf9Hob7GPC7Kewo JcfqGpuA==; Received: from 089144202225.atnat0011.highway.a1.net ([89.144.202.225] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jFIUF-0007Ej-D6; Fri, 20 Mar 2020 14:18:59 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org, Alexey Kardashevskiy Cc: linuxppc-dev@lists.ozlabs.org, Lu Baolu , Greg Kroah-Hartman , Joerg Roedel , Robin Murphy , linux-kernel@vger.kernel.org Subject: generic DMA bypass flag v2 Date: Fri, 20 Mar 2020 15:16:38 +0100 Message-Id: <20200320141640.366360-1-hch@lst.de> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 Hi all, I've recently beeing chatting with Lu about using dma-iommu and per-device DMA ops in the intel IOMMU driver, and one missing feature in dma-iommu is a bypass mode where the direct mapping is used even when an iommu is attached to improve performance. The powerpc code already has a similar mode, so I'd like to move it to the core DMA mapping code. As part of that I noticed that the current powerpc code has a little bug in that it used the wrong check in the dma_sync_* routines to see if the direct mapping code is used. These two patches just add the generic code and move powerpc over, the intel IOMMU bits will require a separate discussion. The x86 AMD Gart code also has a bypass mode, but it is a lot strange, so I'm not going to touch it for now. Changes since v1: - rebased to the current dma-mapping-for-next tree