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 44F66C352A2 for ; Fri, 7 Feb 2020 10:47:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1D91B206CC for ; Fri, 7 Feb 2020 10:47:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726819AbgBGKrk (ORCPT ); Fri, 7 Feb 2020 05:47:40 -0500 Received: from foss.arm.com ([217.140.110.172]:38734 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726587AbgBGKrk (ORCPT ); Fri, 7 Feb 2020 05:47:40 -0500 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 D3CC130E; Fri, 7 Feb 2020 02:47:39 -0800 (PST) Received: from bogus (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 409953F52E; Fri, 7 Feb 2020 02:47:38 -0800 (PST) Date: Fri, 7 Feb 2020 10:47:36 +0000 From: Sudeep Holla To: Marc Zyngier Cc: peng.fan@nxp.com, robh+dt@kernel.org, mark.rutland@arm.com, devicetree@vger.kernel.org, f.fainelli@gmail.com, viresh.kumar@linaro.org, linux-kernel@vger.kernel.org, linux-imx@nxp.com, andre.przywara@arm.com, linux-arm-kernel@lists.infradead.org, Sudeep Holla Subject: Re: [PATCH 1/2] dt-bindings: arm: arm,scmi: add smc/hvc transports Message-ID: <20200207104736.GB36345@bogus> References: <1580994086-17850-1-git-send-email-peng.fan@nxp.com> <1580994086-17850-2-git-send-email-peng.fan@nxp.com> <7875e2533c4ba23b8ca0a2a296699497@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7875e2533c4ba23b8ca0a2a296699497@kernel.org> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Fri, Feb 07, 2020 at 10:08:36AM +0000, Marc Zyngier wrote: > On 2020-02-06 13:01, peng.fan@nxp.com wrote: > > From: Peng Fan > > > > SCMI could use SMC/HVC as tranports, so add into devicetree > > binding doc. > > > > Signed-off-by: Peng Fan > > --- > > Documentation/devicetree/bindings/arm/arm,scmi.txt | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/Documentation/devicetree/bindings/arm/arm,scmi.txt > > b/Documentation/devicetree/bindings/arm/arm,scmi.txt > > index f493d69e6194..03cff8b55a93 100644 > > --- a/Documentation/devicetree/bindings/arm/arm,scmi.txt > > +++ b/Documentation/devicetree/bindings/arm/arm,scmi.txt > > @@ -14,7 +14,7 @@ Required properties: > > > > The scmi node with the following properties shall be under the > > /firmware/ node. > > > > -- compatible : shall be "arm,scmi" > > +- compatible : shall be "arm,scmi" or "arm,scmi-smc" > > - mboxes: List of phandle and mailbox channel specifiers. It should > > contain > > exactly one or two mailboxes, one for transmitting messages("tx") > > and another optional for receiving the notifications("rx") if > > @@ -25,6 +25,8 @@ The scmi node with the following properties shall be > > under the /firmware/ node. > > protocol identifier for a given sub-node. > > - #size-cells : should be '0' as 'reg' property doesn't have any size > > associated with it. > > +- arm,smc-id : SMC id required when using smc transports > > +- arm,hvc-id : HVC id required when using hvc transports > > > > Optional properties: > > Not directly related to DT: Why do we need to distinguish between SMC and > HVC? IIUC you want just one property to get the function ID ? Does that align with what you are saying ? I wanted to ask the same question and I see no need for 2 different properties. > Other SMC/HVC capable protocols are able to pick the right one based on the > PSCI conduit. > This make it clear, but I am asking to be sure. > This is how the Spectre mitigations work already. Why is that any different? > I don't see any need for it to be different. -- Regards, Sudeep