From patchwork Fri May 24 00:06:48 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Atish Patra X-Patchwork-Id: 10958999 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0590813AD for ; Fri, 24 May 2019 00:07:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E00F127F7F for ; Fri, 24 May 2019 00:07:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D34E228724; Fri, 24 May 2019 00:07:50 +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=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 5140327F7F for ; Fri, 24 May 2019 00:07:50 +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:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: 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: List-Owner; bh=64zaFOSBQHDdul9T2iawUsqlDQNd38DPm3k0nsYR3fw=; b=iHhoi+09QTKiAy HT02VuMetqN0qD5e8MMFYCyddVTIZ3rE6YYYq4Qxt6aN4HiVsE+M7riRdLEWobucvFFuqGEsOmiSZ PK26+OtiyuRq9qEqJjLu3rjCnIiFqnmOfJVrVlYboaEgr8TAQVoP9tabTG/LhO4MotVsItcUgryLL Dc8jO9hxeDA1FfeeIH+8owyv8FlFZT4z8U4eVtB+bAaGf6U5rE7UBArrzvUPkvFZIeO8Qh5wY3lMY 3Q0+b+EyJoJpXoFAbXTVZFIityarRDHQf4WI8tL+j2+0fz/GJ7HGWT5xQOZ5FYloGSrWNKWBHoa+n 6cLI2Sj0pji19h4N9neA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hTxkQ-0000VX-5J; Fri, 24 May 2019 00:07:46 +0000 Received: from esa2.hgst.iphmx.com ([68.232.143.124]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hTxk7-00008t-Ee; Fri, 24 May 2019 00:07:28 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1558656482; x=1590192482; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=GED2GA9QcE13vUl5xR4mTzXTMt8Lm/cPPiiomsp+YVU=; b=G/Q8q8TLMHl2/5VJl4xDv/LWbpc1wgdQ+2UTM+BIxLtFoRrPi1M6dy9m X9D9U5r9UVy6tnMLG4nuUwobGaOhxC+6B06s3iYrOohU2uHNKunh/mz5X mrrD+XyuUUZn/bfKumlyQzAEBJ02VD7EH7C8zeUgNgEGeLBrJ3LM9FqM1 zXd79mPRm19AFTJ7eDDeJg7GZESyZQUg6dvQmINSlpEQPh/3oMllBIbco /Nee4RYDeQpNzgn5Jpndz6aNxrAqHqHJ40fHL3JGB8beios5+qJLMU7kN jTwJc+uYMz8MaM0SxmeO1Z/J6x0+haSIbmHBjY7mT7PEDS/4facMKrqp9 Q==; X-IronPort-AV: E=Sophos;i="5.60,505,1549900800"; d="scan'208";a="208480802" Received: from uls-op-cesaip01.wdc.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 24 May 2019 08:08:00 +0800 IronPort-SDR: 27d3WTz/YmFr1IFG7KHNHsw5alO1cMIl27A8FkLADJ1p7WSDBc9eu5H4lUWj4oSHCHOIcodqYR QeyDB2MHzJFnASIRVDiI8CJ2f0cQ0uX3cjNKFoQO8WoZ3cGUULshyP9SJLX1GyXJ4Y2n9FpjVi HC/0N7gbGlA9IemBVxVAODznhfEH7qv1HDntW9qc+pfjaxO2RTSCxuDGDI+kPeKqaYRc5MNJgY EMYGhxWZvJzuLK3MXQ/TlRQIT3EQY4EIoilFbZ2+qIQgEkSyq7Q5mlWr7PKssxBpQoCT4q6jPW RAgUEVbNPvNOnVyh2aoNetCB Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep01.wdc.com with ESMTP; 23 May 2019 16:42:46 -0700 IronPort-SDR: 341jEcSs6pSCjQ27H/KQc3ZHyavI69B6lqsdo28+lkRjZYQlZhRKYL6fFHFnMqSkPyjC2YpFjN zgf5XrjEEjr8QBjGGvG/0WiRgUIkA5iz8PX4gzAfQfnrfLobcPvqyxh88Fr+aWw08EN4duinZA dJFRPpcTHeyc31oDWsGsAXy71D7XdUkLHJjHUOyGTxH2Xh+EsBD7biDVoZpWsOaOoMwVsWGTY/ F3mUzmQiap9ZbpO05xrow58G5i4810s27v9u9q9+PMc7WJdNlSpQNtGGQrPnl/RT9bVMZu4Qdj xyg= Received: from jedi-01.sdcorp.global.sandisk.com (HELO jedi-01.int.fusionio.com) ([10.11.143.218]) by uls-op-cesaip02.wdc.com with ESMTP; 23 May 2019 17:07:26 -0700 From: Atish Patra To: linux-kernel@vger.kernel.org Subject: [RFT PATCH v5 1/5] Documentation: DT: arm: add support for sockets defining package boundaries Date: Thu, 23 May 2019 17:06:48 -0700 Message-Id: <20190524000653.13005-2-atish.patra@wdc.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190524000653.13005-1-atish.patra@wdc.com> References: <20190524000653.13005-1-atish.patra@wdc.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190523_170727_521807_EC57C830 X-CRM114-Status: GOOD ( 15.60 ) 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 , "Rafael J. Wysocki" , "Peter Zijlstra \(Intel\)" , Catalin Marinas , Palmer Dabbelt , Will Deacon , Atish Patra , linux-riscv@lists.infradead.org, Morten Rasmussen , Rob Herring , Anup Patel , Ingo Molnar , devicetree@vger.kernel.org, Albert Ou , Rob Herring , Paul Walmsley , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Greg Kroah-Hartman , Jeremy Linton , Otto Sabart , Sudeep Holla , Andreas Schwab 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 From: Sudeep Holla 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. However this hierarchical representation of clusters does not allow to describe what topology level actually represents the physical package or the socket boundary, which is a key piece of information to be used by an operating system to optimize resource allocation and scheduling. Lets add a new "socket" node type in the cpu-map node to describe the same. Signed-off-by: Sudeep Holla Reviewed-by: Rob Herring --- .../devicetree/bindings/arm/topology.txt | 52 ++++++++++++++----- 1 file changed, 39 insertions(+), 13 deletions(-) diff --git a/Documentation/devicetree/bindings/arm/topology.txt b/Documentation/devicetree/bindings/arm/topology.txt index b0d80c0fb265..3b8febb46dad 100644 --- a/Documentation/devicetree/bindings/arm/topology.txt +++ b/Documentation/devicetree/bindings/arm/topology.txt @@ -9,6 +9,7 @@ ARM topology binding description In an ARM system, the hierarchy of CPUs is defined through three entities that are used to describe the layout of physical CPUs in the system: +- socket - cluster - core - thread @@ -63,21 +64,23 @@ nodes are listed. The cpu-map node's child nodes can be: - - one or more cluster nodes + - one or more cluster nodes or + - one or more socket nodes in a multi-socket system Any other configuration is considered invalid. -The cpu-map node can only contain three types of child nodes: +The cpu-map node can only contain 4 types of child nodes: +- socket node - cluster node - core node - thread node whose bindings are described in paragraph 3. -The nodes describing the CPU topology (cluster/core/thread) can only -be defined within the cpu-map node and every core/thread in the system -must be defined within the topology. Any other configuration is +The nodes describing the CPU topology (socket/cluster/core/thread) can +only be defined within the cpu-map node and every core/thread in the +system must be defined within the topology. Any other configuration is invalid and therefore must be ignored. =========================================== @@ -85,26 +88,44 @@ invalid and therefore must be ignored. =========================================== cpu-map child nodes must follow a naming convention where the node name -must be "clusterN", "coreN", "threadN" depending on the node type (ie -cluster/core/thread) (where N = {0, 1, ...} is the node number; nodes which -are siblings within a single common parent node must be given a unique and +must be "socketN", "clusterN", "coreN", "threadN" depending on the node type +(ie socket/cluster/core/thread) (where N = {0, 1, ...} is the node number; nodes +which are siblings within a single common parent node must be given a unique and sequential N value, starting from 0). cpu-map child nodes which do not share a common parent node can have the same name (ie same number N as other cpu-map child nodes at different device tree levels) since name uniqueness will be guaranteed by the device tree hierarchy. =========================================== -3 - cluster/core/thread node bindings +3 - socket/cluster/core/thread node bindings =========================================== -Bindings for cluster/cpu/thread nodes are defined as follows: +Bindings for socket/cluster/cpu/thread nodes are defined as follows: + +- socket node + + Description: must be declared within a cpu-map node, one node + per physical socket in the system. A system can + contain single or multiple physical socket. + The association of sockets and NUMA nodes is beyond + the scope of this bindings, please refer [2] for + NUMA bindings. + + This node is optional for a single socket system. + + The socket node name must be "socketN" as described in 2.1 above. + A socket node can not be a leaf node. + + A socket node's child nodes must be one or more cluster nodes. + + Any other configuration is considered invalid. - cluster node Description: must be declared within a cpu-map node, one node per cluster. A system can contain several layers of - clustering and cluster nodes can be contained in parent - cluster nodes. + clustering within a single physical socket and cluster + nodes can be contained in parent cluster nodes. The cluster node name must be "clusterN" as described in 2.1 above. A cluster node can not be a leaf node. @@ -164,13 +185,15 @@ Bindings for cluster/cpu/thread nodes are defined as follows: 4 - Example dts =========================================== -Example 1 (ARM 64-bit, 16-cpu system, two clusters of clusters): +Example 1 (ARM 64-bit, 16-cpu system, two clusters of clusters in a single +physical socket): cpus { #size-cells = <0>; #address-cells = <2>; cpu-map { + socket0 { cluster0 { cluster0 { core0 { @@ -253,6 +276,7 @@ cpus { }; }; }; + }; CPU0: cpu@0 { device_type = "cpu"; @@ -473,3 +497,5 @@ cpus { =============================================================================== [1] ARM Linux kernel documentation Documentation/devicetree/bindings/arm/cpus.yaml +[2] Devicetree NUMA binding description + Documentation/devicetree/bindings/numa.txt