Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752654AbbDBQX1 (ORCPT ); Thu, 2 Apr 2015 12:23:27 -0400 Received: from mail-by2on0146.outbound.protection.outlook.com ([207.46.100.146]:1768 "EHLO na01-by2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751209AbbDBQXZ (ORCPT ); Thu, 2 Apr 2015 12:23:25 -0400 Authentication-Results: spf=none (sender IP is 165.204.84.221) smtp.mailfrom=amd.com; 8bytes.org; dkim=none (message not signed) header.d=none; X-WSS-ID: 0NM6TIV-07-0KZ-02 X-M-MSG: Message-ID: <551D6CF5.1010604@amd.com> Date: Thu, 2 Apr 2015 11:23:17 -0500 From: Aravind Gopalakrishnan User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Ingo Molnar CC: , , , , , , , , Subject: Re: [PATCH] x86, aperture: Check for GART before accessing GART registers References: <1427898728-3434-1-git-send-email-Aravind.Gopalakrishnan@amd.com> <20150402100135.GA5210@gmail.com> <551D661D.3030000@amd.com> <20150402160634.GB8045@gmail.com> In-Reply-To: <20150402160634.GB8045@gmail.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.180.168.240] X-EOPAttributedMessage: 0 X-Forefront-Antispam-Report: CIP:165.204.84.221;CTRY:US;IPV:NLI;EFV:NLI;BMV:1;SFV:NSPM;SFS:(10019020)(6009001)(428002)(51704005)(164054003)(199003)(479174004)(377454003)(24454002)(189002)(47776003)(23746002)(77096005)(2950100001)(80316001)(54356999)(83506001)(87266999)(50986999)(65816999)(86362001)(92566002)(33656002)(76176999)(64126003)(106466001)(87936001)(120886001)(59896002)(105586002)(110136001)(50466002)(77156002)(36756003)(62966003)(93886004)(46102003)(61793002);DIR:OUT;SFP:1102;SCL:1;SRVR:DM2PR0201MB0895;H:atltwp01.amd.com;FPR:;SPF:None;MLV:sfv;A:1;MX:1;LANG:en; X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:DM2PR0201MB0895; X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:; X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(601004)(5002010)(5005006);SRVR:DM2PR0201MB0895;BCL:0;PCL:0;RULEID:;SRVR:DM2PR0201MB0895; X-Forefront-PRVS: 0534947130 X-OriginatorOrg: amd4.onmicrosoft.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Apr 2015 16:23:21.6233 (UTC) X-MS-Exchange-CrossTenant-Id: fde4dada-be84-483f-92cc-e026cbee8e96 X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=fde4dada-be84-483f-92cc-e026cbee8e96;Ip=[165.204.84.221];Helo=[atltwp01.amd.com] X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM2PR0201MB0895 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1116 Lines: 31 On 4/2/2015 11:06 AM, Ingo Molnar wrote: > > > We get "AGP:" messages on kernel logs like this- > [ 0.000000] AGP: Node 0: aperture [bus addr 0x00000000-0x01ffffff] (32MB) > [ 0.000000] AGP: Your BIOS doesn't leave a aperture memory hole > [ 0.000000] AGP: Please enable the IOMMU option in the BIOS setup > [ 0.000000] AGP: This costs you 64MB of RAM > [ 0.000000] AGP: Mapping aperture over RAM [mem 0xd4000000-0xd7ffffff] > (65536KB) > > These are just noise on processors which have no GART. > agreed. > >> We can avoid calling allocate_aperture() and would not have to >> memblock_reserve() 64MB of RAM. >> Also, we can avoid having to loop through all PCI buses, devices (twice) >> searching for AGP bridge if we bail out early. > Makes sense. Mind adding this info to the changelog and resend? > > Sure, will do that and resend. Thanks, -Aravind. -- 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/