From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3919CC32789 for ; Fri, 2 Nov 2018 15:51:06 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E05422081F for ; Fri, 2 Nov 2018 15:51:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="R01jTyiE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E05422081F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org 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:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=CNE4YmQRZx+fN1x61QExWciJ27eXOepYKbhPNd3CiGE=; b=R01jTyiEGCPfoM 2Vl3PaYspQeAZGYaes+3rmYO7gnEKAb6Phz8he4SRemVp+YzdqNi1BBHd9ssfYvAcamCWBPKlH2pz DSe7wmrKLqzIW87/nk59eJwY7QW1eRQ5audISTvFKjA9k7czoMRIXxt7Wt4Dz3C6yFy0saRxOV9ht v/sd+uLTipPH7Cz3UHIbzhVdM3OoOP2ubrPSz7l/iJUICECaGCxE/TBS4MGTWoqs1Rb0yVGDVSejo 3T8N5y62Q1k5eknlra7LE+0+wAAI0tcbbQH36syl9lMiRDv4qP4vInHdpS0PLbvxixXAhBo49mStK EXyNWm+FobOo1FeAodCQ==; 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 1gIbiy-0005pF-Nr; Fri, 02 Nov 2018 15:51:04 +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 4.90_1 #2 (Red Hat Linux)) id 1gIbiw-0005nq-3o for linux-riscv@lists.infradead.org; Fri, 02 Nov 2018 15:51:03 +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 E40131596; Fri, 2 Nov 2018 08:50:46 -0700 (PDT) Received: from e107155-lin (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 72CDA3F718; Fri, 2 Nov 2018 08:50:44 -0700 (PDT) Date: Fri, 2 Nov 2018 15:50:38 +0000 From: Sudeep Holla To: Rob Herring Subject: Re: [RFC 1/2] dt-bindings: topology: Add RISC-V cpu topology. Message-ID: <20181102155038.GA21067@e107155-lin> References: <1541113468-22097-1-git-send-email-atish.patra@wdc.com> <1541113468-22097-2-git-send-email-atish.patra@wdc.com> <20181102133100.GA13130@e107155-lin> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181102_085102_164230_6924E442 X-CRM114-Status: GOOD ( 19.06 ) X-BeenThere: linux-riscv@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 , devicetree@vger.kernel.org, Damien.LeMoal@wdc.com, alankao@andestech.com, Zong Li , Anup Patel , Palmer Dabbelt , "linux-kernel@vger.kernel.org" , Christoph Hellwig , Atish Patra , Sudeep Holla , linux-riscv@lists.infradead.org, Thomas Gleixner Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org Message-ID: <20181102155038.ly1eroI5mupGDdYZPMF-9vT1J6tw06b95E_ZRj46sJg@z> On Fri, Nov 02, 2018 at 10:11:38AM -0500, Rob Herring wrote: > On Fri, Nov 2, 2018 at 8:31 AM Sudeep Holla wrote: > > > > On Fri, Nov 02, 2018 at 08:09:39AM -0500, Rob Herring wrote: > > > On Thu, Nov 1, 2018 at 6:04 PM Atish Patra wrote: > > > > > > > > Define a RISC-V cpu topology. This is based on cpu-map in ARM world. > > > > But it doesn't need a separate thread node for defining SMT systems. > > > > Multiple cpu phandle properties can be parsed to identify the sibling > > > > hardware threads. Moreover, we do not have cluster concept in RISC-V. > > > > So package is a better word choice than cluster for RISC-V. > > > > > > There was a proposal to add package info for ARM recently. Not sure > > > what happened to that, but we don't need 2 different ways. > > > > > > > We still need that, I can brush it up and post what Lorenzo had previously > > proposed[1]. We want to keep both DT and ACPI CPU topology story aligned. > > Frankly, I don't care what the ACPI story is. I care whether each cpu Sorry I meant feature parity with ACPI and didn't refer to the mechanics. > arch does its own thing in DT or not. If a package prop works for > RISC-V folks and that happens to align with ACPI, then okay. Though I > tend to prefer a package represented as a node rather than a property > as I think that's more consistent. > Sounds good. One of the reason for making it *optional* property is for backward compatibility. But we should be able to deal with that even with node. > Any comments on the thread aspect (whether it has ever been used)? > Though I think thread as a node level is more consistent with each > topology level being a node (same with package). > Not 100% sure, the only multi threaded core in the market I know is Cavium TX2 which is ACPI. -- Regards, Sudeep _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv