Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751760AbdG1C2x (ORCPT ); Thu, 27 Jul 2017 22:28:53 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:28809 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751722AbdG1C2v (ORCPT ); Thu, 27 Jul 2017 22:28:51 -0400 X-IronPort-AV: E=Sophos;i="5.40,423,1496073600"; d="scan'208";a="21933189" Subject: Re: [PATCH v7 12/13] ACPI / init: Invoke early ACPI initialization earlier To: "Zheng, Lv" , "bhe@redhat.com" References: <1500011554-9784-1-git-send-email-douly.fnst@cn.fujitsu.com> <1500011554-9784-13-git-send-email-douly.fnst@cn.fujitsu.com> <1AE640813FDE7649BE1B193DEA596E886CEE2130@SHSMSX101.ccr.corp.intel.com> <20170718084521.GC2344@x1> <0c13e0de-9a37-2992-ef00-20b6ad67dbc5@cn.fujitsu.com> <1AE640813FDE7649BE1B193DEA596E886CEE8365@SHSMSX101.ccr.corp.intel.com> CC: "x86@kernel.org" , "linux-kernel@vger.kernel.org" , "tglx@linutronix.de" , "mingo@kernel.org" , "hpa@zytor.com" , "ebiederm@xmission.com" , "peterz@infradead.org" , "izumi.taku@jp.fujitsu.com" , "tokunaga.keiich@jp.fujitsu.com" , "linux-acpi@vger.kernel.org" , "Rafael J. Wysocki" , Julian Wollrath From: Dou Liyang Message-ID: Date: Fri, 28 Jul 2017 10:28:34 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <1AE640813FDE7649BE1B193DEA596E886CEE8365@SHSMSX101.ccr.corp.intel.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.167.226.106] X-yoursite-MailScanner-ID: 7B90C46BA940.AA68C X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: douly.fnst@cn.fujitsu.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3871 Lines: 127 Hi, Zheng At 07/28/2017 09:53 AM, Zheng, Lv wrote: [...] >> >>> Dmar hardware support interrupt remapping and io remapping separately. But >>> intel_iommu_init() is called later than intel_prepare_irq_remapping(). >>> So what if make dmar_table_init() a reentrant function? You can just >>> have a try, but maybe not a good idea, the dmar table will be parsed >>> twice. >> >> Yes, It is precisely one reason that I gave up invoking >> acpi_put_table(). > > Parsing a table twice is not a problem on x86. > If you check the code, there are many examples. > It's actually required if you want to use a table both in early stage and late stage. > I am sorry I don't explain clearly. Yeah, in current kernel, The DMAR table has been parsed twice as well. one is in detect_intel_iommu(), the other is in dmar_table_init(). Here we focus on the reentrant dmar_table_init(), this func contains many callback for parsing different DMAR type structures, such as DRHD, RMRR. acpi_put_table() can release the mapped DMAR address, but we should clear the remapping structure types manually. and I think parsing these DMAR type structures again may have an influence on interrupt remapping. Thanks, dou. > Thanks > >> >> Thanks, >> >> dou. >> >>> >>>> >>>> >>>> Thanks, >>>> >>>> dou. >>>>> >>>>> Thanks >>>>> Lv >>>>> >>>>>> From: Dou Liyang [mailto:douly.fnst@cn.fujitsu.com] >>>>>> Sent: Friday, July 14, 2017 1:53 PM >>>>>> To: x86@kernel.org; linux-kernel@vger.kernel.org >>>>>> Cc: tglx@linutronix.de; mingo@kernel.org; hpa@zytor.com; ebiederm@xmission.com; bhe@redhat.com; >>>>>> peterz@infradead.org; izumi.taku@jp.fujitsu.com; tokunaga.keiich@jp.fujitsu.com; Dou Liyang >>>>>> ; linux-acpi@vger.kernel.org; Rafael J. Wysocki ; >> Zheng, >>>>>> Lv ; Julian Wollrath >>>>>> Subject: [PATCH v7 12/13] ACPI / init: Invoke early ACPI initialization earlier >>>>>> >>>>>> Linux uses acpi_early_init() to put the ACPI table management into >>>>>> the late stage from the early stage where the mapped ACPI tables is >>>>>> temporary and should be unmapped. >>>>>> >>>>>> But, now initializing interrupt delivery mode should map and parse the >>>>>> DMAR table earlier in the early stage. This causes an ACPI error when >>>>>> Linux reallocates the ACPI root tables. Because Linux doesn't unmapped >>>>>> the DMAR table after using in the early stage. >>>>>> >>>>>> Invoke acpi_early_init() earlier before late_time_init(), Keep the DMAR >>>>>> be mapped and parsed in late stage like before. >>>>>> >>>>>> Reported-by: Xiaolong Ye >>>>>> Signed-off-by: Dou Liyang >>>>>> Cc: linux-acpi@vger.kernel.org >>>>>> Cc: Rafael J. Wysocki >>>>>> Cc: Zheng, Lv >>>>>> Cc: Julian Wollrath >>>>>> --- >>>>>> Test in my own PC(Lenovo M4340). >>>>>> Ask help for doing regression testing for the bug said in commit c4e1acbb35e4 >>>>>> ("ACPI / init: Invoke early ACPI initialization later"). >>>>>> >>>>>> init/main.c | 2 +- >>>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>>> >>>>>> diff --git a/init/main.c b/init/main.c >>>>>> index df58a41..7a09467 100644 >>>>>> --- a/init/main.c >>>>>> +++ b/init/main.c >>>>>> @@ -654,12 +654,12 @@ asmlinkage __visible void __init start_kernel(void) >>>>>> kmemleak_init(); >>>>>> setup_per_cpu_pageset(); >>>>>> numa_policy_init(); >>>>>> + acpi_early_init(); >>>>>> if (late_time_init) >>>>>> late_time_init(); >>>>>> calibrate_delay(); >>>>>> pidmap_init(); >>>>>> anon_vma_init(); >>>>>> - acpi_early_init(); >>>>>> #ifdef CONFIG_X86 >>>>>> if (efi_enabled(EFI_RUNTIME_SERVICES)) >>>>>> efi_enter_virtual_mode(); >>>>>> -- >>>>>> 2.5.5 >>>>>> >>>>>> >>>>> >>>>> >>>>> >>>>> >>>> >>>> >>> >>> >>> >> > > > >