From mboxrd@z Thu Jan 1 00:00:00 1970 From: Huang Ying Subject: Re: APEI: Can not request iomem region for GARs Date: Tue, 30 Aug 2011 08:57:14 +0800 Message-ID: <4E5C356A.7000701@intel.com> References: <4E520149.3010802@intel.com> <4E571D66.1070302@intel.com> <4E5AEAF4.3000800@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: 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 In-Reply-To: Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Bjorn Helgaas Cc: Pavel Ivanov , linux-kernel , "linux-acpi@vger.kernel.org" , "Brown, Len" 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