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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 C4B28C352A3 for ; Mon, 10 Feb 2020 16:35:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A5CE8208C3 for ; Mon, 10 Feb 2020 16:35:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727959AbgBJQfi (ORCPT ); Mon, 10 Feb 2020 11:35:38 -0500 Received: from mout.kundenserver.de ([212.227.126.134]:33485 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727728AbgBJQfi (ORCPT ); Mon, 10 Feb 2020 11:35:38 -0500 Received: from mail-qk1-f171.google.com ([209.85.222.171]) by mrelayeu.kundenserver.de (mreue009 [212.227.15.129]) with ESMTPSA (Nemesis) id 1MGi6k-1jEzXu1hEg-00Dqpm; Mon, 10 Feb 2020 17:35:36 +0100 Received: by mail-qk1-f171.google.com with SMTP id v2so2187528qkj.2; Mon, 10 Feb 2020 08:35:36 -0800 (PST) X-Gm-Message-State: APjAAAVVx0J8A10B02bxeCUpWUP5XdIx6hHAQsY7iviRMyonrgZoj7lI 5rLAp4d2UYUBq/ihuLzWQgNW74oTx1bIMMV92f4= X-Google-Smtp-Source: APXvYqzwsmadsnYEYT4Ek1X+K2TCw5F0cgvsuN+fGPdnvrDqGEuNOwdA27X52ZmPPjeq150xVoqs1ywlchc9VsQt1FA= X-Received: by 2002:a37:e409:: with SMTP id y9mr2224481qkf.352.1581352535220; Mon, 10 Feb 2020 08:35:35 -0800 (PST) MIME-Version: 1.0 References: <1579123790-6894-1-git-send-email-eajames@linux.ibm.com> <1579123790-6894-7-git-send-email-eajames@linux.ibm.com> In-Reply-To: <1579123790-6894-7-git-send-email-eajames@linux.ibm.com> From: Arnd Bergmann Date: Mon, 10 Feb 2020 17:35:19 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v6 06/12] soc: aspeed: Add XDMA Engine Driver To: Eddie James Cc: linux-aspeed , "linux-kernel@vger.kernel.org" , DTML , Mark Rutland , Jason Cooper , Marc Zyngier , Rob Herring , Thomas Gleixner , Joel Stanley , Andrew Jeffery Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:KgmaCXhhi62tw/qrUQ2htx/WJKvvMAHgg9nLtHPVn3jhIkucDc2 gNZq30+E2/tsO80jCn7Yn/lR6QX0oc0lX2izkSQv72eom6vFE+fFQY3vUnOIIiqwgi8J/6u wkQ6EY2V2G0QuNfIapa2AQqoj60eVS2LCRPTZNnm7nmyOD7da/TjLJ2l2dLvZzMLPmO6NL4 QsVOi2oPC0HhiiDBg+UWg== X-UI-Out-Filterresults: notjunk:1;V03:K0:+WPvPvM77DQ=:WC04ClHZb9hN7ms7ilSGHT Ol5vmqQbjtPokUdWAEiRkeGq/c79ZrWJOk2dgwUqpPoh91yRnRNJmeFxo+gD2lhphpAsmFYSD 2ym6tpnSJwhOQwqY0SB+NXsuZ5ZlgUhLIjdnqis5wqdZhk5SaM20Y+tMSSo923b1FlNPEh3Bq zMQO38Un5mAsK36QJ3qgftN+o738/jQ7HsedTxVc2KWJ8Wm//CIwWTD1mkNnuttvXO7auqfVg zTcdfWGRBTLYi3U7E/evyOCSO/fdiiIh8xUlKJYcL2UU2Da52sY9F/bm8D49UcG7CtGqYBXmn 67oDqPhBqid8SOI6hrXKTXo4tsBjDZDKuS9/JU95iHsS1wGgT9jGDcN/W1KaLBXYfsQErUe5F 45zAuBPxP2elzwcpksUcpY38O9J//7CaI6fISVFHaJStdXzRuW3mCSqSyTJvmgZNtA1MKpYG8 cv6lNXMXGPhKroXIgDjp/I6A797//llb/zbdt17eu1gos9/JIyTaiJf7X02mrpf0zAxHWSgZk jEbYL1iOXiFo/qdzTO9t3g/rDvSBrn+u3dDuVBcO32iaIcAasQ9VgMNWW4Ge1kZ5VV5Z5IZJR AMHmACk7jA+StdkMUoNlYtg7/9V2e2Jw0mIxYc+6m8AJoqJyC6mALaud47sfwavcHqKq122Ri gY+LEw4Dyzw0fNzvA1n8ogrfZAjLDDsLDYELomJmq1wQjbxdYftKJvY5kHiOotuSkNjL4OMMA os7m3U1Zuw+zZPd2dOiyDOsZsKigTBSX5n7OmdyUzYKJCyTBqHTw8qtpNF/TEETa+92HdQWYW IkA7gDTldfMis/m/nvIhhfKTj6ivQLWh3EgOgznaTtBTuGkUp8= Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Wed, Jan 15, 2020 at 10:31 PM Eddie James wrote: > > The XDMA engine embedded in the AST2500 and AST2600 SOCs performs PCI > DMA operations between the SOC (acting as a BMC) and a host processor > in a server. > > This commit adds a driver to control the XDMA engine and adds functions > to initialize the hardware and memory and start DMA operations. > > Signed-off-by: Eddie James Hi Eddie, I'm missing the bigger picture in the description here, how does this fit into the PCIe endpoint framework and the dmaengine subsystem? Does the AST2500 show up as a PCIe device in the host, or do you just inject DMAs into the host and hope that bypasses the IOMMU? If it shows up as an endpoint, how does the endpoint driver link into the dma driver? Arnd