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[209.85.220.41]) by mx.google.com with SMTPS id y27sor5133270lfk.120.2021.10.06.00.15.57 for (Google Transport Security); Wed, 06 Oct 2021 00:15:58 -0700 (PDT) Received-SPF: pass (google.com: domain of jens.wiklander@linaro.org designates 209.85.220.41 as permitted sender) client-ip=209.85.220.41; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=qZ2J2cmj; spf=pass (google.com: domain of jens.wiklander@linaro.org designates 209.85.220.41 as permitted sender) smtp.mailfrom=jens.wiklander@linaro.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org 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=PdeM8UbG6Pab7HmxalQEP1N1T2sjEbz2bRI7Q6V1fKdWwBarHeRd2zbBjwduHxMRRY NVSchLFRg49TmF/ZjCVqstFbTLlQNfuB/CO6R/LtCxhijDhc4jCmyRMsROhPob+JeG/0 as2f996LqsREE5BR6ZkqcVfhms+TJb3OAf73xRfZ3gRKXfc7n56ujdK5XMYepzxq04Oi ECw910w99df5BpD8yhpDEXRT3BuYJ7FBxdNLJMafJ/+NkZmPgWBZdswdVFbdwmmq0HpN 2W7Al7ozyYQEAx8BWix63n/YpLz2TNYwZfB7hnaNifnMNltNxPkPICWPjhGRLjvYf+71 2boQ== X-Gm-Message-State: AOAM530nHGx/2KoRielV/ZayM+NJVnFAoIiZvWn/chtoSI5xLBimx2sv bVowktFZFXx56or86s3Gz483NUN4 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) Return-Path: 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 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(+) -- 2.31.1 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 ==============