From nobody Tue Feb 10 04:17:24 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5AD83396B7F; Wed, 14 Jan 2026 11:48:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768391291; cv=none; b=Vku9kUAJX03L/FIxIdFaLwTkUJR0/gVpvkKVgSuGckHnzykvonr+7i9n/Qj/BUEfN0M/Ft0pX1TttsmuH7lvfA4HIPgSaliiUK2QMWcdvivFCdWkp1NKyu+AD4j5pU8IiHd1N27efE1jKr3Dn6czNTgrxSww5ovTLl3rDJ2iibM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768391291; c=relaxed/simple; bh=11wXPYjHj3h165OF2QwSpTZnR8wyVKglIC99G0i0DeA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kEGZLZOeQbK7rMiZmKb6KkM3tOZTNaJW9XoCjVNrNwZ4BgzNiHgzd6BgiO5qIyW4JBsc8PHtOYOI2Xe73eRsqQgfNLHoQ15vPBwp9rJgufsyixVas09E0LglE42QmBpq/9NAw4Usn36iA9FncrS+ZiOzT9Zb3JEEthFVbBd7B+Q= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 BA52D1515; Wed, 14 Jan 2026 03:47:56 -0800 (PST) Received: from pluto.fritz.box (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 25C843F59E; Wed, 14 Jan 2026 03:47:59 -0800 (PST) From: Cristian Marussi To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, arm-scmi@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: sudeep.holla@arm.com, james.quinlan@broadcom.com, f.fainelli@gmail.com, vincent.guittot@linaro.org, etienne.carriere@st.com, peng.fan@oss.nxp.com, michal.simek@amd.com, dan.carpenter@linaro.org, d-gole@ti.com, jonathan.cameron@huawei.com, elif.topuz@arm.com, lukasz.luba@arm.com, philip.radford@arm.com, souvik.chakravarty@arm.com, Cristian Marussi Subject: [PATCH v2 11/17] fs/stlmfs: Document alternative ioctl based binary interface Date: Wed, 14 Jan 2026 11:46:15 +0000 Message-ID: <20260114114638.2290765-12-cristian.marussi@arm.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260114114638.2290765-1-cristian.marussi@arm.com> References: <20260114114638.2290765-1-cristian.marussi@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Document the additionally provided special files and their usage in the context of the alternative binary ioctl-based interface. Signed-off-by: Cristian Marussi --- Documentation/filesystems/stlmfs.rst | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/Documentation/filesystems/stlmfs.rst b/Documentation/filesyste= ms/stlmfs.rst index 7ea8878098f7..5c23f7e5f12c 100644 --- a/Documentation/filesystems/stlmfs.rst +++ b/Documentation/filesystems/stlmfs.rst @@ -112,6 +112,7 @@ the following directory structure:: |-- all_des_enable |-- all_des_tstamp_enable |-- available_update_intervals_ms + |-- control |-- current_update_interval_ms |-- de_implementation_version |-- des/ @@ -129,6 +130,10 @@ the following directory structure:: |-- tlm_enable `-- version =20 +.. Note:: + The control/ special file can be used to use the alternative + binary interface described in include/uapi/linux/scmi.h + Each subdirectory is defined as follows. =20 des/ @@ -189,6 +194,7 @@ values, as in:: scmi_tlm_0/groups/0/ |-- available_update_intervals_ms |-- composing_des + |-- control |-- current_update_interval_ms |-- des_bulk_read |-- des_single_sample_read @@ -196,3 +202,21 @@ values, as in:: |-- intervals_discrete `-- tstamp_enable =20 +Alternative Binary Interfaces - Special files +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D + +Special files are populated across the filesystem so as to implement the s= upport +of more performant alternative binary interfaces that can be used instead = of the +main human readable ABI. + +IOCTLs Interface +---------------- + +The ioctl-based interface is detailed in:: + + include/uapi/linux/smci.h + +The filesystem provides special files named *control/* to be used with the +ioctl interface mentioned above: note that the behaviour of some of the io= ctls +is dependent on which *control/* file is used to invoke them (as detailed = in the +UAPI header above). --=20 2.52.0