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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 2002AC3A5A4 for ; Fri, 30 Aug 2019 09:30:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EE63821726 for ; Fri, 30 Aug 2019 09:30:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728008AbfH3JaN (ORCPT ); Fri, 30 Aug 2019 05:30:13 -0400 Received: from foss.arm.com ([217.140.110.172]:57042 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727242AbfH3JaM (ORCPT ); Fri, 30 Aug 2019 05:30:12 -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 D1382344; Fri, 30 Aug 2019 02:30:11 -0700 (PDT) Received: from bogus (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 60AAF3F718; Fri, 30 Aug 2019 02:30:10 -0700 (PDT) Date: Fri, 30 Aug 2019 10:30:05 +0100 From: Sudeep Holla To: Peng Fan Cc: Jassi Brar , "robh+dt@kernel.org" , "mark.rutland@arm.com" , "andre.przywara@arm.com" , "f.fainelli@gmail.com" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , dl-linux-imx , Sudeep Holla Subject: Re: [PATCH v5 1/2] dt-bindings: mailbox: add binding doc for the ARM SMC/HVC mailbox Message-ID: <20190830093005.GA31297@bogus> References: <1567004515-3567-1-git-send-email-peng.fan@nxp.com> <1567004515-3567-2-git-send-email-peng.fan@nxp.com> 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 Fri, Aug 30, 2019 at 07:37:41AM +0000, Peng Fan wrote: > Hi Jassi, > > > I think there could be channel for TEE, and channel for Linux. > > > For virtualization case, there could be dedicated channel for each VM. > > > > > I am talking from Linux pov. Functions 0xfe and 0xff above, can't both be > > active at the same time, right? > > If I get your point correctly, > On UP, both could not be active. On SMP, tx/rx could be both active, anyway > this depends on secure firmware and Linux firmware design. > Just to confirm, we can't have SMC/HVC based Rx channel as there's no *architectural* way to achieve it. So it can be based on some interrupt from secure side and hence will be a *different* type of channel/controller. Sorry to make this point repeatedly, but juts to be absolutely clear: as it stands, SMC/HVC can be used only for Tx today. -- Regards, Sudeep