From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [RFC 1/2] dt-bindings: topology: Add RISC-V cpu topology. Date: Fri, 2 Nov 2018 10:11:38 -0500 Message-ID: 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-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <20181102133100.GA13130@e107155-lin> Sender: linux-kernel-owner@vger.kernel.org To: Sudeep Holla Cc: Atish Patra , linux-riscv@lists.infradead.org, Palmer Dabbelt , Anup Patel , Christoph Hellwig , Damien.LeMoal@wdc.com, Thomas Gleixner , Mark Rutland , "linux-kernel@vger.kernel.org" , devicetree@vger.kernel.org, alankao@andestech.com, Zong Li List-Id: devicetree@vger.kernel.org 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 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. 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). Rob