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=-10.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 18BDFC2D0DB for ; Wed, 29 Jan 2020 16:40:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E9B4D20716 for ; Wed, 29 Jan 2020 16:40:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727156AbgA2QkX (ORCPT ); Wed, 29 Jan 2020 11:40:23 -0500 Received: from foss.arm.com ([217.140.110.172]:43474 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726645AbgA2QkW (ORCPT ); Wed, 29 Jan 2020 11:40:22 -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 B84B2328; Wed, 29 Jan 2020 08:40:21 -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 B87F43F52E; Wed, 29 Jan 2020 08:40:20 -0800 (PST) Date: Wed, 29 Jan 2020 16:40:18 +0000 From: Sudeep Holla To: Etienne Carriere Cc: Peng Fan , "f.fainelli@gmail.com" , "andre.przywara@arm.com" , "linux-kernel@vger.kernel.org" , etienne carriere , Sudeep Holla Subject: Re: [PATCH v11 2/2] mailbox: introduce ARM SMC based mailbox Message-ID: <20200129164018.GE36496@bogus> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Wed, Jan 29, 2020 at 04:01:07PM +0100, Etienne Carriere wrote: > Hello Peng, > > On Mon, 27 Jan 2020 at 13:58, Peng Fan wrote: > > > > > Subject: Re: [PATCH v11 2/2] mailbox: introduce ARM SMC based mailbox > > > > > > Hello Peng and all, > > > > > > > > > > From: Peng Fan > > > > > > > > This mailbox driver implements a mailbox which signals transmitted > > > > data via an ARM smc (secure monitor call) instruction. The mailbox > > > > receiver is implemented in firmware and can synchronously return data > > > > when it returns execution to the non-secure world again. > > > > An asynchronous receive path is not implemented. > > > > This allows the usage of a mailbox to trigger firmware actions on SoCs > > > > which either don't have a separate management processor or on which > > > > such a core is not available. A user of this mailbox could be the SCP > > > > interface. > > > > > > > > Modified from Andre Przywara's v2 patch > > > > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore > > > > .kernel.org%2Fpatchwork%2Fpatch%2F812999%2F&data=02%7C01%7 > > > Cpeng.fa > > > > > > > n%40nxp.com%7C735cc6cd00404082bf8c08d79f67b93a%7C686ea1d3bc2b4 > > > c6fa92cd > > > > > > > 99c5c301635%7C0%7C0%7C637153140140878278&sdata=m0lcAEIr0ZP > > > tyPHorSW > > > > NYgjfI5p0genJLlhqHMIHBg0%3D&reserved=0 > > > > > > > > Reviewed-by: Florian Fainelli > > > > Reviewed-by: Andre Przywara > > > > Signed-off-by: Peng Fan > > > > > > I've successfully tested your change on my board. It is a stm32mp1 with TZ > > > secure hardening and I run an OP-TEE firmware (possibly a TF-A > > > sp_min) with a SCMI server for clock and reset. Upstream in progress. > > > The platform uses 2 instances of your SMC based mailbox device driver > > > (2 mailboxes). Works nice with your change. > > > > > > You can add my T-b tag: Tested-by: Etienne Carriere > > > > > > > Thanks, but this patch has been dropped. > > > > Per Sudeep, we all use smc transport, not smc mailbox , > > I'll post patch in a few days based on the transport split patch. > > Ok, i am syncing. > > > > > > > FYI, I'll (hopefully soon) post a change proposal in U-Boot ML for an equvalent > > > 'SMC based mailbox' driver and SCMI agent protocol/device drivers for clock > > > and reset controllers. > > > > Great to know you did scmi agent code in U-Boot. Do you have some public repo > > for access? > > I've created a P-R on my github repo to share until I submit to u-boot: > https://github.com/etienne-lms/u-boot/pull/3 > > I guess I will change my u-boot proposal and get a SMC SCMI transport > outside of the mailbox framework. > Unless U-boot has mailbox framework or you are importing it, it's better to keep U-boot implementation simple as SMC transport which I think you already do. I had a look at the implementation[1], it shouldn't change much other than if you prefer not to use "mailbox" terminology. I don't understand the reason for even using the mailbox term there in the first place. -- Regards, Sudeep [1] https://github.com/etienne-lms/u-boot/pull/3/commits/34812c9175436f6a082f77347c5384393757c233