From patchwork Mon Jan 22 17:15:34 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Pieralisi X-Patchwork-Id: 10178919 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id BEF95601D5 for ; Mon, 22 Jan 2018 17:16:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A3F832842A for ; Mon, 22 Jan 2018 17:16:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 96F4F2842D; Mon, 22 Jan 2018 17:16:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id BD1AD2842A for ; Mon, 22 Jan 2018 17:16:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=sXODXxg2zjSmbN50DfmhgKc1evvMaazZ63yoxdodTu4=; b=Lqr ufKsJWXZ7dm9S8SlDf6ZzUUYnIn8VnOIlBV8XHGwl9FL++v05e+i/5Qd1jGz+nSO++hHeAQI/TThv /1MtoCNG0JxHcXzjWrIz1wjMkPgO+nVPZ5TFB6GvtbEsPmJ4CNZhJLgPpguwW+70nrJyj1PT7l5pp Ae5gqzbsVHFHrhTDs5GgEeG1rB9G0qJSGkKGygfOdWsoylo740pTwkODimP30S8UMoovftNdVzpJd I/HoE5z5HktW1Ltc2XkEZCy7tPnLhp9zX50dp/zHnOUbdPTr7UcQr5J2YSxSvDr7l7aJK2907eFcK UtXxCCq9fULprLASPAsf2KL84TGm++g==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.89 #1 (Red Hat Linux)) id 1edfhU-0002CU-SM; Mon, 22 Jan 2018 17:16:04 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.89 #1 (Red Hat Linux)) id 1edfhR-0002C1-GU for linux-arm-kernel@lists.infradead.org; Mon, 22 Jan 2018 17:16:03 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2582E1435; Mon, 22 Jan 2018 09:15:47 -0800 (PST) Received: from e107981-ln.cambridge.arm.com (e107981-ln.cambridge.arm.com [10.1.207.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9ED663F53D; Mon, 22 Jan 2018 09:15:45 -0800 (PST) From: Lorenzo Pieralisi To: devicetree@vger.kernel.org Subject: [RFC PATCH] Documentation: DT: arm: Add topology property to define package boundaries Date: Mon, 22 Jan 2018 17:15:34 +0000 Message-Id: <20180122171534.7681-1-lorenzo.pieralisi@arm.com> X-Mailer: git-send-email 2.15.0 X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Lorenzo Pieralisi , Jeremy Linton , Rob Herring , Sudeep Holla , Morten Rasmussen , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The current ARM DT topology description provides the operating system with a topological view of the system that is based on leaf nodes representing either cores or threads (in an SMT system) and a hierarchical set of cluster nodes that creates a hierarchical topology view of how those cores and threads are grouped. As opposed to the ACPI topology description ([1], PPTT table), this hierarchical representation of clusters does not allow to describe what topology level actually represents the physical package boundary, which is a key piece of information to be used by an operating system to optimize resource allocation and scheduling. Define an optional, backward compatible boolean property for cluster nodes that, by reusing the ACPI nomenclature, add to the ARM DT topological description a binding to define what cluster level represents a physical package boundary. [1] http://www.uefi.org/sites/default/files/resources/ACPI_6_2.pdf Signed-off-by: Lorenzo Pieralisi Cc: Rob Herring Cc: Sudeep Holla Cc: Jeremy Linton Cc: Morten Rasmussen Cc: Mark Rutland --- Documentation/devicetree/bindings/arm/topology.txt | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/Documentation/devicetree/bindings/arm/topology.txt b/Documentation/devicetree/bindings/arm/topology.txt index de9eb0486630..8e78d76b0671 100644 --- a/Documentation/devicetree/bindings/arm/topology.txt +++ b/Documentation/devicetree/bindings/arm/topology.txt @@ -109,6 +109,15 @@ Bindings for cluster/cpu/thread nodes are defined as follows: The cluster node name must be "clusterN" as described in 2.1 above. A cluster node can not be a leaf node. + Properties for cluster nodes: + + - physical-package + Usage: optional + Value type: + Definition: if present the cluster node represents the + boundary of a physical package, whether socketed + or surface mounted. + A cluster node's child nodes must be: - one or more cluster nodes; or