Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754057AbbGBSZd (ORCPT ); Thu, 2 Jul 2015 14:25:33 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49020 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753874AbbGBSZY (ORCPT ); Thu, 2 Jul 2015 14:25:24 -0400 Message-ID: <55958211.5010607@redhat.com> Date: Thu, 02 Jul 2015 12:25:21 -0600 From: Al Stone User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Hanjun Guo , "Rafael J. Wysocki" CC: Sudeep Holla , Al Stone , "linux-acpi@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "rjw@rjwysocki.net" , "lenb@kernel.org" , Catalin Marinas , Will Deacon , "tglx@linutronix.de" , "jason@lakedaemon.net" , "linux-kernel@vger.kernel.org" , "linaro-acpi@lists.linaro.org" , "linaro-kernel@lists.linaro.org" , "patches@linaro.org" Subject: Re: [PATCH v2 0/3] Correct for ACPI 5.1->6.0 spec changes in MADT GICC entries References: <1434666968-1543-1-git-send-email-al.stone@linaro.org> <5592CCE6.6040604@arm.com> <5592D1FF.7040208@redhat.com> <55934B3D.6060106@huawei.com> In-Reply-To: <55934B3D.6060106@huawei.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3777 Lines: 84 On 06/30/2015 08:06 PM, Hanjun Guo wrote: > On 2015/7/1 2:35, Rafael J. Wysocki wrote: >> On Tue, Jun 30, 2015 at 8:25 PM, Rafael J. Wysocki wrote: >>> Hi Al, >>> >>> On Tue, Jun 30, 2015 at 7:29 PM, Al Stone wrote: >>>> On 06/30/2015 11:07 AM, Sudeep Holla wrote: >>>>> Hi Al, >>>>> >>>>> On 18/06/15 23:36, Al Stone wrote: >>>>>> In the ACPI 5.1 version of the spec, the struct for the GICC subtable >>>>>> (struct acpi_madt_generic_interrupt) of the MADT is 76 bytes long; in >>>>>> ACPI 6.0, the struct is 80 bytes long. But, there is only one definition >>>>>> in ACPICA for this struct -- and that is the 6.0 version. Hence, when >>>>>> BAD_MADT_ENTRY() compares the struct size to the length in the GICC >>>>>> subtable, it fails if 5.1 structs are in use, and there are systems in >>>>>> the wild that have them. >>>>>> >>>>>> Note that this was found in linux-next and these patches apply against >>>>>> that tree and the arm64 kernel tree; 4.1-rc8 does not appear to have this >>>>>> problem since it still has the 5.1 struct definition. >>>>>> >>>>>> Even though there is precendent in ia64 code for ignoring the changes in >>>>>> size, this patch set instead tries to verify correctness. The first patch >>>>>> in the set adds macros for easily using the ACPI spec version. The second >>>>>> patch adds the BAD_MADT_GICC_ENTRY() macro that uses the version macros to >>>>>> check the GICC subtable only, accounting for the difference in specification >>>>>> versions that are possible. The final patch replaces BAD_MADT_ENTRY usage >>>>>> with the BAD_MADT_GICC_ENTRY macro in arm64 code, which is currently the >>>>>> only architecture affected. The BAD_MADT_ENTRY() will continue to work as >>>>>> is for all other MADT subtables. >>>>>> >>>>> We need to get this series or a patch to remove the check(similar to >>>>> ia64) based on what Rafael prefers. Without that, platforms using ACPI >>>>> on ARM64 fails to boot with latest mainline. This blocks any testing on >>>>> ARM64/ACPI systems. >>>>> >>>>> Regards, >>>>> Sudeep >>>> I have not received any other feedback than some Reviewed-bys from >>>> Hanjun and an ACK from Will for the arm64 patch. >>>> >>>> And absolutely agreed: this is a blocker for arm64/ACPI, starting with >>>> the ACPICA 20150515 patches which appear to have gone in with 4.2-rc1. >>>> >>>> Rafael? Ping? >>> I overlooked the fact that this was needed to fix a recent regression, >>> sorry about that. >>> >>> Actually, if your patch fixes an error introduced by a specific >>> commit, it is good to use the Fixes: tag to indicate that. Which I >>> still would like to do, so which commit is fixed by this? >>> >>>> Do we need these to go through your tree or the arm64 >>>> tree? Without this series (or an ia64-like solution), we have ACPI >>>> systems in the field that cannot boot. >>> I'm not quite sure why the definition of BAD_MADT_GICC_ENTRY has to go >>> into include/linux/acpi.h. Why is it necessary in there? >> Like what about defining it in linux/irqchip/arm-gic-acpi.h for example? >> > > This BAD_MADT_GICC_ENTRY is both used by SMP init and GIC irqchip init for > ARM64, would it be good to put BAD_MADT_GICC_ENTRY in arch/arm64/include/asm/acpi.h? > > Thanks > Hanjun Ah, right. Good point. Let me try it in that file, then. It is -- for the time being -- arm64 specific. -- ciao, al ----------------------------------- Al Stone Software Engineer Red Hat, Inc. ahs3@redhat.com ----------------------------------- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/