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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75E9EC4167D for ; Tue, 14 Nov 2023 13:18:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232741AbjKNNSx (ORCPT ); Tue, 14 Nov 2023 08:18:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57580 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231203AbjKNNSv (ORCPT ); Tue, 14 Nov 2023 08:18:51 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 8836E196; Tue, 14 Nov 2023 05:18:48 -0800 (PST) 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 73274C15; Tue, 14 Nov 2023 05:19:33 -0800 (PST) Received: from [10.1.196.40] (e121345-lin.cambridge.arm.com [10.1.196.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 98F5B3F6C4; Tue, 14 Nov 2023 05:18:43 -0800 (PST) Message-ID: <3daaa2aa-61d4-40db-b36d-cd825a340d2b@arm.com> Date: Tue, 14 Nov 2023 13:18:35 +0000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 6/8] dt-bindings: reserved-memory: Add secure CMA reserved memory range To: =?UTF-8?B?WW9uZyBXdSAo5ZC05YuHKQ==?= , "matthias.bgg@gmail.com" , "christian.koenig@amd.com" , "krzysztof.kozlowski@linaro.org" , "robh+dt@kernel.org" , "sumit.semwal@linaro.org" Cc: "linux-kernel@vger.kernel.org" , "linux-mediatek@lists.infradead.org" , "jstultz@google.com" , "nicolas@ndufresne.ca" , "linaro-mm-sig@lists.linaro.org" , "linux-media@vger.kernel.org" , "devicetree@vger.kernel.org" , =?UTF-8?B?SmlhbmppYW8gWmVuZyAo5pu+5YGl5aejKQ==?= , =?UTF-8?B?S3VvaG9uZyBXYW5nICjnjovlnIvptLsp?= , "quic_vjitta@quicinc.com" , "ckoenig.leichtzumerken@gmail.com" , "jkardatzke@google.com" , "conor+dt@kernel.org" , "Brian.Starkey@arm.com" , "benjamin.gaignard@collabora.com" , "tjmercier@google.com" , "krzysztof.kozlowski+dt@linaro.org" , "dri-devel@lists.freedesktop.org" , "linux-arm-kernel@lists.infradead.org" , "joakim.bech@linaro.org" , "angelogioacchino.delregno@collabora.com" References: <20231111111559.8218-1-yong.wu@mediatek.com> <20231111111559.8218-7-yong.wu@mediatek.com> <0ccee72f-98ac-4a08-9253-9c22dad4d95a@linaro.org> <5d7b2458b8d1896ce575f4ed2d413f4e8eeb92b4.camel@mediatek.com> Content-Language: en-GB From: Robin Murphy In-Reply-To: <5d7b2458b8d1896ce575f4ed2d413f4e8eeb92b4.camel@mediatek.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 13/11/2023 6:37 am, Yong Wu (吴勇) wrote: [...] >>> +properties: >>> + compatible: >>> + const: secure_cma_region >> >> Still wrong compatible. Look at other bindings - there is nowhere >> underscore. Look at other reserved memory bindings especially. >> >> Also, CMA is a Linux thingy, so either not suitable for bindings at >> all, >> or you need Linux specific compatible. I don't quite get why do you >> evennot >> put CMA there - adding Linux specific stuff will get obvious >> pushback... > > Thanks. I will change to: secure-region. Is this ok? No, the previous discussion went off in entirely the wrong direction. To reiterate, the point of the binding is not to describe the expected usage of the thing nor the general concept of the thing, but to describe the actual thing itself. There are any number of different ways software may interact with a "secure region", so that is meaningless as a compatible. It needs to describe *this* secure memory interface offered by *this* TEE, so that software knows that to use it requires making those particular SiP calls with that particular UUID etc. Thanks, Robin.