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From: Jens Wiklander <>
Cc: Jerome Forissier <>,
	Etienne Carriere <>,
	Sumit Garg <>,
	Vincent Guittot <>,
	Rob Herring <>,
	Jonathan Corbet <>,
	Ard Biesheuvel <>, Marc Zyngier <>,
	Jens Wiklander <>
Subject: [PATCH v3 1/6] docs: staging/tee.rst: add a section on OP-TEE notifications
Date: Fri, 23 Jul 2021 11:44:17 +0200	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

Adds a section on notifications used by OP-TEE, synchronous and

Signed-off-by: Jens Wiklander <>
 Documentation/staging/tee.rst | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/Documentation/staging/tee.rst b/Documentation/staging/tee.rst
index 4d4b5f889603..37bdd097336f 100644
--- a/Documentation/staging/tee.rst
+++ b/Documentation/staging/tee.rst
@@ -184,6 +184,33 @@ 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
+   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 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 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

  reply	other threads:[~2021-07-23  9:44 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-23  9:44 [PATCH v3 0/6] Asynchronous notifications from secure world Jens Wiklander
2021-07-23  9:44 ` Jens Wiklander [this message]
2021-07-23 10:16   ` [PATCH v3 1/6] docs: staging/tee.rst: add a section on OP-TEE notifications Marc Zyngier
2021-07-27  7:46     ` Jens Wiklander
2021-07-27  8:32       ` Marc Zyngier
2021-07-27 14:57         ` Jens Wiklander
2021-08-04 14:39           ` Marc Zyngier
2021-07-23  9:44 ` [PATCH v3 2/6] dt-bindings: arm: optee: add interrupt property Jens Wiklander
2021-07-23  9:44 ` [PATCH v3 3/6] tee: fix put order in teedev_close_context() Jens Wiklander
2021-07-23  9:44 ` [PATCH v3 4/6] tee: add tee_dev_open_helper() primitive Jens Wiklander
2021-07-23  9:44 ` [PATCH v3 5/6] optee: separate notification functions Jens Wiklander
2021-07-23  9:44 ` [PATCH v3 6/6] optee: add asynchronous notifications Jens Wiklander

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