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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 5AAD9C54FD0 for ; Wed, 25 Mar 2020 12:51:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C3DE2078A for ; Wed, 25 Mar 2020 12:51:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727504AbgCYMvg (ORCPT ); Wed, 25 Mar 2020 08:51:36 -0400 Received: from foss.arm.com ([217.140.110.172]:48004 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727290AbgCYMvg (ORCPT ); Wed, 25 Mar 2020 08:51:36 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 495FC31B; Wed, 25 Mar 2020 05:51:35 -0700 (PDT) Received: from red-moon.cambridge.arm.com (unknown [10.57.20.165]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3F43B3F71F; Wed, 25 Mar 2020 05:51:30 -0700 (PDT) Date: Wed, 25 Mar 2020 12:51:18 +0000 From: Lorenzo Pieralisi To: laurentiu.tudor@nxp.com Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org, robin.murphy@arm.com, ard.biesheuvel@linaro.org, ioana.ciornei@nxp.com, diana.craciun@oss.nxp.com, maz@kernel.org, jon@solid-run.com, pankaj.bansal@nxp.com, makarand.pawagi@nxp.com, calvin.johnson@nxp.com, V.Sethi@nxp.com, cristian.sovaiala@nxp.com, Stuart.Yoder@arm.com, jeremy.linton@arm.com, joro@8bytes.org, tglx@linutronix.de, jason@lakedaemon.net Subject: Re: [RFC PATCH 1/4] bus: fsl-mc: add custom .dma_configure implementation Message-ID: <20200325125109.GA5430@red-moon.cambridge.arm.com> References: <20200227100542.13819-1-laurentiu.tudor@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200227100542.13819-1-laurentiu.tudor@nxp.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 27, 2020 at 12:05:39PM +0200, laurentiu.tudor@nxp.com wrote: > From: Laurentiu Tudor > > The devices on this bus are not discovered by way of device tree > but by queries to the firmware. It makes little sense to trick the > generic of layer into thinking that these devices are of related so > that we can get our dma configuration. Instead of doing that, add > our custom dma configuration implementation. > > Signed-off-by: Laurentiu Tudor > --- > drivers/bus/fsl-mc/fsl-mc-bus.c | 31 ++++++++++++++++++++++++++++++- > 1 file changed, 30 insertions(+), 1 deletion(-) > > diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c > index 36eb25f82c8e..eafaa0e0b906 100644 > --- a/drivers/bus/fsl-mc/fsl-mc-bus.c > +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c > @@ -132,11 +132,40 @@ static int fsl_mc_bus_uevent(struct device *dev, struct kobj_uevent_env *env) > static int fsl_mc_dma_configure(struct device *dev) > { > struct device *dma_dev = dev; > + struct iommu_fwspec *fwspec; > + const struct iommu_ops *iommu_ops; > + struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev); > + int ret; > + u32 icid; > > while (dev_is_fsl_mc(dma_dev)) > dma_dev = dma_dev->parent; > > - return of_dma_configure(dev, dma_dev->of_node, 0); > + fwspec = dev_iommu_fwspec_get(dma_dev); > + if (!fwspec) > + return -ENODEV; > + iommu_ops = iommu_ops_from_fwnode(fwspec->iommu_fwnode); > + if (!iommu_ops) > + return -ENODEV; > + > + ret = iommu_fwspec_init(dev, fwspec->iommu_fwnode, iommu_ops); > + if (ret) > + return ret; > + > + icid = mc_dev->icid; > + ret = iommu_fwspec_add_ids(dev, &icid, 1); I see. So with this patch we would use the MC named component only to retrieve the iommu_ops - the streamid are injected directly here bypassing OF/IORT bindings translations altogether. Am I reading this code correctly ? Thanks, Lorenzo > + if (ret) > + return ret; > + > + if (!device_iommu_mapped(dev)) { > + ret = iommu_probe_device(dev); > + if (ret) > + return ret; > + } > + > + arch_setup_dma_ops(dev, 0, *dma_dev->dma_mask + 1, iommu_ops, true); > + > + return 0; > } > > static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, > -- > 2.17.1 >