From patchwork Wed Feb 2 14:48:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Winiarska, Iwona" X-Patchwork-Id: 1587670 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=DL1/C+c1; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=openbmc-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4JplNS1FMfz9sCD for ; Thu, 3 Feb 2022 02:00:40 +1100 (AEDT) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4JplNR63G9z3bbS for ; Thu, 3 Feb 2022 02:00:39 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=DL1/C+c1; dkim-atps=neutral X-Original-To: openbmc@lists.ozlabs.org Delivered-To: openbmc@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=intel.com (client-ip=134.134.136.100; helo=mga07.intel.com; envelope-from=iwona.winiarska@intel.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=DL1/C+c1; dkim-atps=neutral Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4JplJZ6kXNz3bb5; Thu, 3 Feb 2022 01:57:18 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1643813839; x=1675349839; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=QMYVyv1FTscgpmw+LGMru7OffCk/NusVJ0zbwclwbtY=; b=DL1/C+c1egIdvemFT/iYOpVI8ttdRywV2CtuHfKfS7dGtbp+y2kXAtyn w85XJzQ3XP1XRfbEeBO3gzcPa5SMjALwcV4P6T99H8Z8np43p5hYaK6yN cL8GiJiamVFlPqEYYElV8kkskdg5XKXqohTcfWQLi3znhpmvBXhceNvcR hvsgs+C63Yk3YxHB9orUVFYs7HiUD7CsxrxcSz2VyaJH+CDp9kdAxyJkc npmEzSyBhKD0N5b5m1bJULNhJGj/fnwPyq3GOD+icV+FW6xUXekRnRup8 znf40K/cfCEEed/bYadKhOXcllY+Xh4wtIdMqXASkkr7XiCzAod1DbtfW A==; X-IronPort-AV: E=McAfee;i="6200,9189,10245"; a="311238064" X-IronPort-AV: E=Sophos;i="5.88,337,1635231600"; d="scan'208";a="311238064" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Feb 2022 06:56:15 -0800 X-IronPort-AV: E=Sophos;i="5.88,337,1635231600"; d="scan'208";a="676456570" Received: from mwnuczyn-mobl.ger.corp.intel.com (HELO localhost) ([10.249.137.160]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Feb 2022 06:56:05 -0800 From: Iwona Winiarska To: linux-kernel@vger.kernel.org, openbmc@lists.ozlabs.org, Greg Kroah-Hartman Subject: [PATCH v7 13/13] docs: Add PECI documentation Date: Wed, 2 Feb 2022 15:48:38 +0100 Message-Id: <20220202144838.163875-14-iwona.winiarska@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220202144838.163875-1-iwona.winiarska@intel.com> References: <20220202144838.163875-1-iwona.winiarska@intel.com> MIME-Version: 1.0 X-BeenThere: openbmc@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development list for OpenBMC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-aspeed@lists.ozlabs.org, linux-doc@vger.kernel.org, Dave Hansen , Zev Weiss , Jonathan Corbet , Pierre-Louis Bossart , Guenter Roeck , devicetree@vger.kernel.org, Jean Delvare , Arnd Bergmann , Billy Tsai , Rob Herring , Borislav Petkov , Iwona Winiarska , Dan Williams , Andy Shevchenko , linux-arm-kernel@lists.infradead.org, linux-hwmon@vger.kernel.org, Tony Luck , Andrew Jeffery , Randy Dunlap , Olof Johansson Errors-To: openbmc-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "openbmc" Add a brief overview of PECI and PECI wire interface. The documentation also contains kernel-doc for PECI subsystem internals and PECI CPU Driver API. Signed-off-by: Iwona Winiarska Reviewed-by: Pierre-Louis Bossart --- Documentation/index.rst | 1 + Documentation/peci/index.rst | 16 +++++++++++ Documentation/peci/peci.rst | 51 ++++++++++++++++++++++++++++++++++++ MAINTAINERS | 1 + 4 files changed, 69 insertions(+) create mode 100644 Documentation/peci/index.rst create mode 100644 Documentation/peci/peci.rst diff --git a/Documentation/index.rst b/Documentation/index.rst index b58692d687f6..1988c19d9daf 100644 --- a/Documentation/index.rst +++ b/Documentation/index.rst @@ -138,6 +138,7 @@ needed). scheduler/index mhi/index tty/index + peci/index Architecture-agnostic documentation ----------------------------------- diff --git a/Documentation/peci/index.rst b/Documentation/peci/index.rst new file mode 100644 index 000000000000..989de10416e7 --- /dev/null +++ b/Documentation/peci/index.rst @@ -0,0 +1,16 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +==================== +Linux PECI Subsystem +==================== + +.. toctree:: + + peci + +.. only:: subproject and html + + Indices + ======= + + * :ref:`genindex` diff --git a/Documentation/peci/peci.rst b/Documentation/peci/peci.rst new file mode 100644 index 000000000000..331b1ec00e22 --- /dev/null +++ b/Documentation/peci/peci.rst @@ -0,0 +1,51 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +======== +Overview +======== + +The Platform Environment Control Interface (PECI) is a communication +interface between Intel processor and management controllers +(e.g. Baseboard Management Controller, BMC). +PECI provides services that allow the management controller to +configure, monitor and debug platform by accessing various registers. +It defines a dedicated command protocol, where the management +controller is acting as a PECI originator and the processor - as +a PECI responder. +PECI can be used in both single processor and multiple-processor based +systems. + +NOTE: +Intel PECI specification is not released as a dedicated document, +instead it is a part of External Design Specification (EDS) for given +Intel CPU. External Design Specifications are usually not publicly +available. + +PECI Wire +--------- + +PECI Wire interface uses a single wire for self-clocking and data +transfer. It does not require any additional control lines - the +physical layer is a self-clocked one-wire bus signal that begins each +bit with a driven, rising edge from an idle near zero volts. The +duration of the signal driven high allows to determine whether the bit +value is logic '0' or logic '1'. PECI Wire also includes variable data +rate established with every message. + +For PECI Wire, each processor package will utilize unique, fixed +addresses within a defined range and that address should +have a fixed relationship with the processor socket ID - if one of the +processors is removed, it does not affect addresses of remaining +processors. + +PECI subsystem internals +------------------------ + +.. kernel-doc:: include/linux/peci.h +.. kernel-doc:: drivers/peci/internal.h +.. kernel-doc:: drivers/peci/core.c +.. kernel-doc:: drivers/peci/request.c + +PECI CPU Driver API +------------------- +.. kernel-doc:: drivers/peci/cpu.c diff --git a/MAINTAINERS b/MAINTAINERS index b7992853a427..23fba6b2609f 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -15117,6 +15117,7 @@ M: Iwona Winiarska L: openbmc@lists.ozlabs.org (moderated for non-subscribers) S: Supported F: Documentation/devicetree/bindings/peci/ +F: Documentation/peci/ F: drivers/peci/ F: include/linux/peci-cpu.h F: include/linux/peci.h