From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lorenzo Pieralisi Subject: Re: [PATCH v3 6/7] arm64: topology: Enable ACPI/PPTT based CPU topology. Date: Fri, 20 Oct 2017 10:22:10 +0100 Message-ID: <20171020092210.GB21060@red-moon> References: <20171012194856.13844-1-jeremy.linton@arm.com> <20171012194856.13844-7-jeremy.linton@arm.com> <20171019155622.GC18883@red-moon> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Jeremy Linton Cc: linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, sudeep.holla@arm.com, hanjun.guo@linaro.org, rjw@rjwysocki.net, will.deacon@arm.com, catalin.marinas@arm.com, gregkh@linuxfoundation.org, viresh.kumar@linaro.org, mark.rutland@arm.com, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, jhugo@codeaurora.org, wangxiongfeng2@huawei.com, Jonathan.Zhang@cavium.com, ahs3@redhat.com, Jayachandran.Nair@cavium.com, austinwc@codeaurora.org List-Id: linux-acpi@vger.kernel.org On Thu, Oct 19, 2017 at 11:54:22AM -0500, Jeremy Linton wrote: [...] > >>+ cpu_topology[cpu].core_id = topology_id; > >>+ topology_id = setup_acpi_cpu_topology(cpu, 2); > >>+ cpu_topology[cpu].cluster_id = topology_id; > >>+ topology_id = setup_acpi_cpu_topology(cpu, max_topo); > > > >If you want a package id (that's just a package tag to group cores), you > >should not use a large level because you know how setup_acpi_cpu_topology()works, you should add an API that allows you to retrieve the package id > >(so that you can use th ACPI_PPTT_PHYSICAL_PACKAGE flag consistenly, > >whatever it represents). > > I don't think the spec requires the use of PHYSICAL_PACKAGE... Am I > misreading it? Which means we need to "pick" a node level to > represent the physical package if one doesn't exist... The specs define a means to detect if a given PPTT node corresponds to a package (I am refraining from stating again that to me that's not clean cut what a package is _architecturally_, I think you know my POV by now) and that's what you need to use to retrieve a packageid for a given cpu, if I understand the aim of the physical package flag. Either that or that flag is completely useless. Lorenzo ACPI 6.2 - Table 5-151 (page 248) Physical package ----------------- Set to 1 if this node of the processor topology represents the boundary of a physical package, whether socketed or surface mounted. Set to 0 if this instance of the processor topology does not represent the boundary of a physical package.