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=-3.6 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 C402DC2BB86 for ; Tue, 14 Apr 2020 12:25:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D63120732 for ; Tue, 14 Apr 2020 12:25:45 +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="Rc1sp0Hp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2440104AbgDNMZm (ORCPT ); Tue, 14 Apr 2020 08:25:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S2440076AbgDNMZ0 (ORCPT ); Tue, 14 Apr 2020 08:25:26 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 134F7C061A0F for ; Tue, 14 Apr 2020 05:25:26 -0700 (PDT) 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=JWvCln94FnW9GCxvyp3f47DfIQwsM51DTgd2A4D782s=; b=Rc1sp0HpIVGZ2DL9BtEZiHycaN tUer5w8J9tKs7IvHWCO6u0GkyQ4AqF2Zitk5jwyQQRy9JrT1LJ8pk1J/f3/4wLT2P8pRgNwHwk5ix KJwPrTEczvIi4jrbRduArDuQBUy5666iQ1fuI7azW7RCOX0HAS0YdNbcT2O9rhL8Ek1PygQTXTcpK md4/Cn4tmDpWjILEzWqF2KEw87BqdZt31xj5TVbFskZkCCXdKxIRXLo9v0esrhsiZnu3KuG0HsaPa 6VW74W3SCuNRUivlOn05TNBq+bSEE8PWG20yhQwO2RaJVjlhD/HZQvvtlZgNktFkWaiTP8Xr1rQtu qohE7vfA==; Received: from [2001:4bb8:180:384b:c70:4a89:bc61:2] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jOKcn-0003eN-Ri; Tue, 14 Apr 2020 12:25:10 +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 v3 Date: Tue, 14 Apr 2020 14:25:02 +0200 Message-Id: <20200414122506.438134-1-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 v2: - move the dma mapping helpers out of line - check for possible direct mappings using the dma mask Changes since v1: - rebased to the current dma-mapping-for-next tree