From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751732Ab1H3A5S (ORCPT ); Mon, 29 Aug 2011 20:57:18 -0400 Received: from mga03.intel.com ([143.182.124.21]:22904 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751583Ab1H3A5Q (ORCPT ); Mon, 29 Aug 2011 20:57:16 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.68,299,1312182000"; d="scan'208";a="43721490" Message-ID: <4E5C356A.7000701@intel.com> Date: Tue, 30 Aug 2011 08:57:14 +0800 From: Huang Ying User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.20) Gecko/20110820 Iceowl/1.0b2 Icedove/3.1.12 MIME-Version: 1.0 To: Bjorn Helgaas CC: Pavel Ivanov , linux-kernel , "linux-acpi@vger.kernel.org" , "Brown, Len" Subject: Re: APEI: Can not request iomem region for GARs References: <4E520149.3010802@intel.com> <4E571D66.1070302@intel.com> <4E5AEAF4.3000800@intel.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/29/2011 10:48 PM, Bjorn Helgaas wrote: > On Sun, Aug 28, 2011 at 7:27 PM, Huang Ying wrote: >> On 08/26/2011 09:43 PM, Bjorn Helgaas wrote: >>> On Thu, Aug 25, 2011 at 10:13 PM, Huang Ying wrote: >>>> Hi, Pavel, >>>> >>>> Sorry, there is a minor issue in the patch. Do you have time to try >>>> the updated version attached. >>> >>> I think Yinghai's patch is a better approach (though it needs a changelog). >>> >>> The ACPI NVS space should not be marked as "busy" by the e820 code in >>> the iomem_resource tree. >>> >>> It's way too complicated to mess around with registering NVS space and >>> trying to deal with it specially in APEI. >> >> ACPI NVS is different, it can be used only by firmware, and its >> interpreter, such as ACPI AML interpreter and APEI interpreter. It can >> not be used by ordinary driver. If my understanding is correct, this is >> why ACPI NVS is marked as busy. > > I don't understand why ACPI NVS is different. If we reserve it in > iomem_resource (without marking it busy), it's already unavailable to > anything else unless you know something connected to the NVS region. I think ACPI NVS can be seen as reserved by ACPI or firmware interpreter. So that, all other drivers should not access it. Best Regards, Huang Ying