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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BF8C2C4332F for ; Wed, 6 Oct 2021 07:16:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A02C561245 for ; Wed, 6 Oct 2021 07:16:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237453AbhJFHRy (ORCPT ); Wed, 6 Oct 2021 03:17:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237408AbhJFHRw (ORCPT ); Wed, 6 Oct 2021 03:17:52 -0400 Received: from mail-lf1-x12e.google.com (mail-lf1-x12e.google.com [IPv6:2a00:1450:4864:20::12e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9F29AC061753 for ; Wed, 6 Oct 2021 00:15:59 -0700 (PDT) Received: by mail-lf1-x12e.google.com with SMTP id n8so6315450lfk.6 for ; Wed, 06 Oct 2021 00:15:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=GhgYsmvqrAxJX0LtPmrYeEXggYv/fhoAephchEquNLc=; b=qZ2J2cmjhB2VqX9Km6Q6J8+EDY/Byt4T6pq0U/D0wN4lykmD63FfuuD+fJIfFHVRZz xKFpUozUWuvyHcdHgrwmFIBMmoP4J197KoLhErtOskLIxdLjFontl7R9pQAyKhpcdPrs K9uWPcqht+rCnG1ENKmU+h2xP38N1+OO9nKfWUqrjr77EDSOV0iHoqd5DKQAEqUaJA2p WGgNwU+oGWY22rtQfAd8dui1O5aJvRnuF+dw8RVjAAz1RkSLBBuKxN8XS6htvnM2ceGl NoQ2U/sUNulNe/Toti1VtEvIc/fXLULR8NcXEZ9zB2uaYQg91ryWFSJsrVXuiOlxrDHF REJg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=GhgYsmvqrAxJX0LtPmrYeEXggYv/fhoAephchEquNLc=; b=VYhO5mAzoH1ArCwmwyHyhTgb5T2kcSN1EWUDDQPaVUf+eBl36LTqNOdWHs2ov2VacU xOccVTyz0DJCXY5Q5WcdgmENWIps/Rll2/nIp0F7RB2uGSzHfDHS16TZfDU2i2mFJhI7 K8xq5DRXL2LVNrBV/CR4Tu33tlBjTykwc1Ip3Akbm0xWkiwTS5labFZtps3pEah6Kg/l HAajzC4DZIwxD1oNziK1SZWjdf6+Z3nHfGfjGzqD4kV0Y4t3JZW5gupgyQBovP/enTcd EW73ynlCgq+oqc6RQe6PWDNsaZ2LxkNotog9I7v5zx0BHMQTHOpYyeQxcW24ytsqznDW Gp/A== X-Gm-Message-State: AOAM530RhKsrUfvzhIVqloK817y2LG636r/QCXRh6S2oTPOvakftenJI +e6ol53bxnrv2gm+Hkj06NSB/A== X-Google-Smtp-Source: ABdhPJwtfl7F40OaEjwCa3PdkHOjNi97Tw8IzsbW5Pthd2LioQtmz+sAMXibm8v3pPCOhxrMakoxGw== X-Received: by 2002:a05:6512:3a83:: with SMTP id q3mr8077047lfu.115.1633504557651; Wed, 06 Oct 2021 00:15:57 -0700 (PDT) Received: from jade.ideon.se ([85.235.10.227]) by smtp.gmail.com with ESMTPSA id y7sm960376lfk.143.2021.10.06.00.15.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 Oct 2021 00:15:57 -0700 (PDT) From: Jens Wiklander To: 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 Cc: Jerome Forissier , Etienne Carriere , Sumit Garg , Vincent Guittot , Rob Herring , Jonathan Corbet , Ard Biesheuvel , Marc Zyngier , Jens Wiklander Subject: [PATCH v6 1/6] docs: staging/tee.rst: add a section on OP-TEE notifications Date: Wed, 6 Oct 2021 09:15:41 +0200 Message-Id: <20211006071546.2540920-2-jens.wiklander@linaro.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211006071546.2540920-1-jens.wiklander@linaro.org> References: <20211006071546.2540920-1-jens.wiklander@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Adds a section on notifications used by OP-TEE, synchronous and asynchronous. Acked-by: Marc Zyngier Signed-off-by: Jens Wiklander --- Documentation/staging/tee.rst | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/Documentation/staging/tee.rst b/Documentation/staging/tee.rst index 4d4b5f889603..3c63d8dcd61e 100644 --- a/Documentation/staging/tee.rst +++ b/Documentation/staging/tee.rst @@ -184,6 +184,36 @@ 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``. Note that one interrupt can represent +multiple notifications. + +One notification value ``OPTEE_SMC_ASYNC_NOTIF_VALUE_DO_BOTTOM_HALF`` has a +special meaning. When this value is received it means that normal world is +supposed to make a yielding call ``OPTEE_MSG_CMD_DO_BOTTOM_HALF``. This +call is done from the thread assisting the interrupt handler. This is a +building block for OP-TEE OS in secure world to implement the top half and +bottom half style of device drivers. + AMD-TEE driver ============== -- 2.31.1