From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757040AbaIIQFc (ORCPT ); Tue, 9 Sep 2014 12:05:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:14245 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753648AbaIIQFb (ORCPT ); Tue, 9 Sep 2014 12:05:31 -0400 Message-ID: <540F24FF.2060302@redhat.com> Date: Tue, 09 Sep 2014 12:04:15 -0400 From: Jon Masters Organization: Red Hat, Inc. User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Hanjun Guo CC: Catalin Marinas , "Rafael J. Wysocki" , Mark Rutland , Olof Johansson , Grant Likely , linaro-acpi@lists.linaro.org, Liviu Dudau , Lv Zheng , Rob Herring , Lorenzo Pieralisi , Daniel Lezcano , Robert Moore , linux-acpi@vger.kernel.org, Charles.Garcia-Tobin@arm.com, Robert Richter , Jason Cooper , Arnd Bergmann , Marc Zyngier , Will Deacon , Tomasz Nowicki , Mark Brown , Bjorn Helgaas , linux-arm-kernel@lists.infradead.org, Graeme Gregory , Randy Dunlap , linux-kernel@vger.kernel.org, Sudeep Holla Subject: Re: [PATCH v3 09/17] ARM64 / ACPI: Parse MADT for SMP initialization References: <1409583475-6978-1-git-send-email-hanjun.guo@linaro.org> <1409583475-6978-10-git-send-email-hanjun.guo@linaro.org> <540E80BD.20801@redhat.com> <540E88A2.1000606@linaro.org> <540E93A0.4040306@redhat.com> <540F2422.90105@linaro.org> In-Reply-To: <540F2422.90105@linaro.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/09/2014 12:00 PM, Hanjun Guo wrote: > On 2014年09月09日 13:44, Jon Masters wrote: >> On 09/09/2014 12:57 AM, Hanjun Guo wrote: >>> Hi Jon, >>> >>> On 2014年09月09日 12:23, Jon Masters wrote: >>>> On 09/01/2014 10:57 AM, Hanjun Guo wrote: >>>>> MADT contains the information for MPIDR which is essential for >>>>> SMP initialization, parse the GIC cpu interface structures to >>>>> get the MPIDR value and map it to cpu_logical_map(), and add >>>>> enabled cpu with valid MPIDR into cpu_possible_map. >>>>> >>>>> ACPI 5.1 only has two explicit methods to boot up SMP, PSCI and >>>>> Parking protocol, but the Parking protocol is only specified for >>>>> ARMv7 now, so make PSCI as the only way for the SMP boot protocol >>>>> before some updates for the ACPI spec or the Parking protocol spec. >>>>> + /* CPU 0 was already initialized */ >>>>> + if (cpu) { >>>>> + if (cpu_ops[cpu]->cpu_init(NULL, cpu)) >>>>> + return -EOPNOTSUPP; >>>>> + >>>>> + /* map the logical cpu id to cpu MPIDR */ >>>>> + cpu_logical_map(cpu) = mpidr; >>>> I'm not sure it's worth noting in a comment or just in the dialogue that >>>> none of these MPIDR values is literally the value in the MPIDR. Linux >>>> doesn't store that anyway (even in the cpu_logical_map), since it is >>>> pre-filtered against MPIDR_HWID_BITMASK to remove the non-affinity level >>>> bits. And since the ACPI5.1 specification requires that non-affinity >>>> bits be zero everything works. But it relies upon this assumption so it >>>> might be worth explicitly masking out the bits when making the call into: >>>> >>>> acpi_map_gic_cpu_interface(processor->arm_mpidr, >>>> processor->flags & ACPI_MADT_ENABLED); >>>> >>>> During the parsing of the processor object's MPIDR value. >>> Yes, I agree with you. When I tested this patch set on our >>> ARM64 platform, I found this problem too. some firmware >>> will just present the real MPIDR value to OS which some reserved >>> bit set to 1, and it will lead to some logic problem in this patch. >>> (actually firmware didn't obey with ACPI spec) >>> >>> I had updated the patch with: >>> >>> + acpi_map_gic_cpu_interface(processor->arm_mpidr & MPIDR_HWID_BITMASK, >>> + processor->flags & ACPI_MADT_ENABLED); >>> >>> and then the problem was gone :) >> Did I miss an updated patch posting then? It is possible... > > No, you didn't miss it, I'm still working on the new version, sorry I didn't > clarify that in my previous email. Thanks. If you could copy me on the next posting that would rock. In a few hours we should have another platform posted as an example. In addition, a couple of lower priority patches (building upon the core ACPI pieces) should be posted as well. Jon.