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=-14.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 F339DC4320A for ; Wed, 18 Aug 2021 18:28:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D4EE961100 for ; Wed, 18 Aug 2021 18:28:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229533AbhHRS2g (ORCPT ); Wed, 18 Aug 2021 14:28:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:33960 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229448AbhHRS2g (ORCPT ); Wed, 18 Aug 2021 14:28:36 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3CC0C60E90; Wed, 18 Aug 2021 18:28:01 +0000 (UTC) Received: from sofa.misterjones.org ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1mGQIB-005ofQ-6o; Wed, 18 Aug 2021 19:27:59 +0100 Date: Wed, 18 Aug 2021 19:27:58 +0100 Message-ID: <878s0ysj4h.wl-maz@kernel.org> From: Marc Zyngier To: Jens Wiklander Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, op-tee@lists.trustedfirmware.org, devicetree@vger.kernel.org, linux-doc@vger.kernel.org, Jerome Forissier , Etienne Carriere , Sumit Garg , Vincent Guittot , Rob Herring , Jonathan Corbet , Ard Biesheuvel Subject: Re: [PATCH v4 1/6] docs: staging/tee.rst: add a section on OP-TEE notifications In-Reply-To: <20210818101849.602257-2-jens.wiklander@linaro.org> References: <20210818101849.602257-1-jens.wiklander@linaro.org> <20210818101849.602257-2-jens.wiklander@linaro.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: jens.wiklander@linaro.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, op-tee@lists.trustedfirmware.org, devicetree@vger.kernel.org, linux-doc@vger.kernel.org, jerome@forissier.org, etienne.carriere@linaro.org, sumit.garg@linaro.org, vincent.guittot@linaro.org, robh+dt@kernel.org, corbet@lwn.net, ardb@kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Wed, 18 Aug 2021 11:18:44 +0100, Jens Wiklander wrote: > > Adds a section on notifications used by OP-TEE, synchronous and > asynchronous. > > Signed-off-by: Jens Wiklander > --- > Documentation/staging/tee.rst | 29 +++++++++++++++++++++++++++++ > 1 file changed, 29 insertions(+) > > diff --git a/Documentation/staging/tee.rst b/Documentation/staging/tee.rst > index 4d4b5f889603..951f07dd026b 100644 > --- a/Documentation/staging/tee.rst > +++ b/Documentation/staging/tee.rst > @@ -184,6 +184,35 @@ order to support device enumeration. In other words, OP-TEE driver invokes this > application to retrieve a list of Trusted Applications which can be registered > as devices on the TEE bus. > > +OP-TEE notifications > +-------------------- > + > +There are two kinds of notifications that secure world can use to make > +normal world aware of some event. > + > +1. Synchronous notifications delivered with ``OPTEE_RPC_CMD_NOTIFICATION`` > + using the ``OPTEE_RPC_NOTIFICATION_SEND`` parameter. > +2. Asynchronous notifications delivered with a combination of a non-secure > + edge-triggered interrupt and a fast call from the non-secure interrupt > + handler. > + > +Synchronous notifications are limited by depending on RPC for delivery, > +this is only usable when secure world is entered with a yielding call via > +``OPTEE_SMC_CALL_WITH_ARG``. This excludes such notifications from secure > +world interrupt handlers. > + > +An asynchronous notification is delivered via a non-secure edge-triggered > +interrupt to an interrupt handler registered in the OP-TEE driver. The > +actual notification value are retrieved with the fast call > +``OPTEE_SMC_GET_ASYNC_NOTIF_VALUE``. One thing you may want to describe whether a single interrupt can represent multiple notification (multiple edge interrupts will happily be coalesced into a single one if not acknowledged before the next notification). Otherwise, Acked-by: Marc Zyngier M. -- Without deviation from the norm, progress is not possible.