From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELupDzy2p6UhiOxSBctlUAN0JFDuxZDiIbRfX2mcSgx362rwUwBM6ApZUMs1IZ/j1tCtFWbs ARC-Seal: i=1; a=rsa-sha256; t=1520264917; cv=none; d=google.com; s=arc-20160816; b=q4AB5J4CmYUJ6+6ZvudIIaBSHl1mY9cYzzq1UrqeRoruJO0mPQZIjVgNbs07xIbYpV R+5KBS2y6KDCWRLhJzcm7eaPVFWfo2xvFZIx59yfTAqlyE7NTJWbG6jjqNWlOshwoCGr I8vZR6tNxiRNHS3EwCyMiVIA7uzioCiSLKzOzkRilYFxHVSyaIbzt4mXMltyw9QkNJ8h qQ84VEV70TURfFXA5H5aPRmBDgxwFreB6XMVo4PEick98RliDUnquweCIERUGj3zFLNS gccKSPqvsd/RuVo2ObI6R7K9baQ9JQWSsy7k6BTgRbAvYHMj65i6Nr4ve8IG9gd8j3e8 3MnQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:from:references:cc:to:subject :arc-authentication-results; bh=ZRrbmiH86GRnpvqsvkwqU7zJSEHrbmfW67NDdypYpPI=; b=gTIUvymowxkWoGTeK9l2VHwOC4bL4CswH7uoAoIaWuDWc3KPkkWltY5rD5ikc8rtg3 Pk8EsgQMlmXWcndMFvFRaRRWZT24KFDguEBX7TRRrLR7PfNz4sncwZd7NxrcALFOPPbn 7nxk+PIoPjCoZ1OdG+CVpYMRtq6K3TCzGjoZPB282cU0OuPSpXDqr0M/R6qFSiwFL3ia U1lsgiFMo1tyZ7KAa8+wqncGOAWaZSqqLgGlqmIgZ1Y+PEtytxl7GbOOAt5DXx+bUcBr 40FVJSUKkn/DfhaxKoy17dEKs3Lhe/tyx6QtskxucJoTVbtoNdxEXINmiFGhr4ci4TFR gyBw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of robin.murphy@arm.com designates 217.140.101.70 as permitted sender) smtp.mailfrom=robin.murphy@arm.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of robin.murphy@arm.com designates 217.140.101.70 as permitted sender) smtp.mailfrom=robin.murphy@arm.com Subject: Re: [PATCH 5/6] dma-mapping: support fsl-mc bus To: Christoph Hellwig Cc: Nipun Gupta , will.deacon@arm.com, mark.rutland@arm.com, catalin.marinas@arm.com, iommu@lists.linux-foundation.org, robh+dt@kernel.org, m.szyprowski@samsung.com, gregkh@linuxfoundation.org, joro@8bytes.org, leoyang.li@nxp.com, shawnguo@kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, bharat.bhushan@nxp.com, stuyoder@gmail.com, laurentiu.tudor@nxp.com References: <1520260166-29387-1-git-send-email-nipun.gupta@nxp.com> <1520260166-29387-6-git-send-email-nipun.gupta@nxp.com> <20180305150814.GA15918@lst.de> From: Robin Murphy Message-ID: <7b4f9972-6aaa-fc9d-3854-d48b19a8051c@arm.com> Date: Mon, 5 Mar 2018 15:48:32 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180305150814.GA15918@lst.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1594108392554438818?= X-GMAIL-MSGID: =?utf-8?q?1594113306082117264?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 05/03/18 15:08, Christoph Hellwig wrote: > We should not add any new hardocded busses here. Please mark them in > OF/ACPI. Unfortunately for us, fsl-mc is conceptually rather like PCI in that it's software-discoverable and the only thing described in DT is the bus "host", thus we need the same sort of thing as for PCI to map from the child devices back to the bus root in order to find the appropriate firmware node. Worse than PCI, though, we wouldn't even have the option of describing child devices statically in firmware at all, since it's actually one of these runtime-configurable "build your own network accelerator" hardware pools where userspace gets to create and destroy "devices" as it likes. Robin. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Murphy Subject: Re: [PATCH 5/6] dma-mapping: support fsl-mc bus Date: Mon, 5 Mar 2018 15:48:32 +0000 Message-ID: <7b4f9972-6aaa-fc9d-3854-d48b19a8051c@arm.com> References: <1520260166-29387-1-git-send-email-nipun.gupta@nxp.com> <1520260166-29387-6-git-send-email-nipun.gupta@nxp.com> <20180305150814.GA15918@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180305150814.GA15918-jcswGhMUV9g@public.gmane.org> Content-Language: en-GB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Christoph Hellwig Cc: mark.rutland-5wv7dgnIgG8@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, stuyoder-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, catalin.marinas-5wv7dgnIgG8@public.gmane.org, linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, leoyang.li-3arQi8VN3Tc@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, shawnguo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On 05/03/18 15:08, Christoph Hellwig wrote: > We should not add any new hardocded busses here. Please mark them in > OF/ACPI. Unfortunately for us, fsl-mc is conceptually rather like PCI in that it's software-discoverable and the only thing described in DT is the bus "host", thus we need the same sort of thing as for PCI to map from the child devices back to the bus root in order to find the appropriate firmware node. Worse than PCI, though, we wouldn't even have the option of describing child devices statically in firmware at all, since it's actually one of these runtime-configurable "build your own network accelerator" hardware pools where userspace gets to create and destroy "devices" as it likes. Robin. From mboxrd@z Thu Jan 1 00:00:00 1970 From: robin.murphy@arm.com (Robin Murphy) Date: Mon, 5 Mar 2018 15:48:32 +0000 Subject: [PATCH 5/6] dma-mapping: support fsl-mc bus In-Reply-To: <20180305150814.GA15918@lst.de> References: <1520260166-29387-1-git-send-email-nipun.gupta@nxp.com> <1520260166-29387-6-git-send-email-nipun.gupta@nxp.com> <20180305150814.GA15918@lst.de> Message-ID: <7b4f9972-6aaa-fc9d-3854-d48b19a8051c@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 05/03/18 15:08, Christoph Hellwig wrote: > We should not add any new hardocded busses here. Please mark them in > OF/ACPI. Unfortunately for us, fsl-mc is conceptually rather like PCI in that it's software-discoverable and the only thing described in DT is the bus "host", thus we need the same sort of thing as for PCI to map from the child devices back to the bus root in order to find the appropriate firmware node. Worse than PCI, though, we wouldn't even have the option of describing child devices statically in firmware at all, since it's actually one of these runtime-configurable "build your own network accelerator" hardware pools where userspace gets to create and destroy "devices" as it likes. Robin.