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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 0D799C2BA19 for ; Tue, 14 Apr 2020 14:32:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E6FC52076B for ; Tue, 14 Apr 2020 14:32:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390935AbgDNOc0 (ORCPT ); Tue, 14 Apr 2020 10:32:26 -0400 Received: from foss.arm.com ([217.140.110.172]:56984 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390932AbgDNOcX (ORCPT ); Tue, 14 Apr 2020 10:32:23 -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 B553E30E; Tue, 14 Apr 2020 07:32:22 -0700 (PDT) Received: from red-moon.cambridge.arm.com (unknown [10.57.27.66]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A55293F73D; Tue, 14 Apr 2020 07:32:18 -0700 (PDT) Date: Tue, 14 Apr 2020 15:32:11 +0100 From: Lorenzo Pieralisi To: Laurentiu Tudor 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: <20200414143211.GA14905@red-moon.cambridge.arm.com> References: <20200227100542.13819-1-laurentiu.tudor@nxp.com> <20200325125109.GA5430@red-moon.cambridge.arm.com> <499fbf9a-416f-d7c7-0655-881d92138a6c@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <499fbf9a-416f-d7c7-0655-881d92138a6c@nxp.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Wed, Mar 25, 2020 at 06:48:55PM +0200, Laurentiu Tudor wrote: > Hi Lorenzo, > > On 3/25/2020 2:51 PM, Lorenzo Pieralisi wrote: > > 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 > > Right. I'd also add that the implementation tries to follow the existing > standard .dma_configure implementations, e.g. of_dma_configure + > of_iommu_configure. I'd also note that similarly to the ACPI case, this > MC FW device is probed as a platform device in the DT scenario, binding > here [1]. > A similar approach is used for the retrieval of the msi irq domain, see > following patch. > > > - the streamid are injected directly here bypassing OF/IORT bindings translations altogether. > > Actually I've submitted a v2 [2] that calls into .of_xlate() to allow > the smmu driver to do some processing on the raw streamid coming from > the firmware. I have not yet tested this with ACPI but expect it to > work, however, it's debatable how valid is this approach in the context > of ACPI. Actually, what I think you need is of_map_rid() (and an IORT equivalent, that I am going to write - generalizing iort_msi_map_rid()). Would that be enough to enable IORT "normal" mappings in the MC bus named components ? Thanks, Lorenzo