From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753408AbcGLG5S (ORCPT ); Tue, 12 Jul 2016 02:57:18 -0400 Received: from mail-bl2nam02on0066.outbound.protection.outlook.com ([104.47.38.66]:14131 "EHLO NAM02-BL2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750853AbcGLG5Q convert rfc822-to-8bit (ORCPT ); Tue, 12 Jul 2016 02:57:16 -0400 Authentication-Results: spf=pass (sender IP is 149.199.60.83) smtp.mailfrom=xilinx.com; free-electrons.com; dkim=none (message not signed) header.d=none;free-electrons.com; dmarc=bestguesspass action=none header.from=xilinx.com; From: Bharat Kumar Gogada To: "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" CC: Arnd Bergmann , Bjorn Helgaas , "Liviu.Dudau@arm.com" , nofooter , "thomas.petazzoni@free-electrons.com" Subject: Purpose of pci_remap_iospace Thread-Topic: Purpose of pci_remap_iospace Thread-Index: AdHcCL/kUAd2y2DJSzGJLmHMsyqJOA== Date: Tue, 12 Jul 2016 06:57:10 +0000 Message-ID: <8520D5D51A55D047800579B094147198258B85DC@XAP-PVEXMBX01.xlnx.xilinx.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [172.23.96.180] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-RCIS-Action: ALLOW X-TM-AS-Product-Ver: IMSS-7.1.0.1224-8.0.0.1202-22444.005 X-TM-AS-User-Approved-Sender: Yes;Yes X-EOPAttributedMessage: 0 X-MS-Office365-Filtering-HT: Tenant X-Forefront-Antispam-Report: CIP:149.199.60.83;IPV:NLI;CTRY:US;EFV:NLI;SFV:NSPM;SFS:(10009020)(6009001)(7916002)(2980300002)(438002)(199003)(189002)(189998001)(8746002)(92566002)(5890100001)(7736002)(3846002)(87936001)(8936002)(102836003)(5250100002)(11100500001)(4326007)(97756001)(81166006)(54356999)(50466002)(33656002)(50986999)(81156014)(8676002)(2501003)(2920100001)(5001770100001)(229853001)(47776003)(356003)(6116002)(23726003)(46406003)(7696003)(586003)(2900100001)(86362001)(5003600100003)(55846006)(2930100002)(305945005)(2906002)(106466001)(63266004)(7846002)(107986001);DIR:OUT;SFP:1101;SCL:1;SRVR:CY1NAM02HT056;H:xsj-pvapsmtpgw01;FPR:;SPF:Pass;PTR:unknown-60-83.xilinx.com;A:1;MX:1;CAT:NONE;LANG:en;CAT:NONE; X-MS-Office365-Filtering-Correlation-Id: a8ce8a9e-8b1c-4a09-4b89-08d3aa21c0ac X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:(8251501002);SRVR:CY1NAM02HT056; X-Microsoft-Antispam-PRVS: <677e3516335e437e825842d70bf4a4ba@CY1NAM02HT056.eop-nam02.prod.protection.outlook.com> X-Exchange-Antispam-Report-Test: UriScan:; X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(601004)(2401047)(13024025)(13015025)(13017025)(13018025)(13023025)(5005006)(8121501046)(3002001)(10201501046)(6055026);SRVR:CY1NAM02HT056;BCL:0;PCL:0;RULEID:;SRVR:CY1NAM02HT056; X-Forefront-PRVS: 0001227049 X-OriginatorOrg: xilinx.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Jul 2016 06:57:12.8781 (UTC) X-MS-Exchange-CrossTenant-Id: 657af505-d5df-48d0-8300-c31994686c5c X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=657af505-d5df-48d0-8300-c31994686c5c;Ip=[149.199.60.83];Helo=[xsj-pvapsmtpgw01] X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY1NAM02HT056 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, I have a query. Can any once explain the purpose of pci_remap_iospace function in root port driver. What is its dependency with architecture ? Here is my understanding, the above API takes PCIe IO resource and its to be mapped CPU address from ranges property and remaps into virtual address space. So my question is who uses this virtual addresses ? When End Point requests for IO BARs doesn't it get from the above resource range (first parameter of API) and do ioremap to access this region ? But why root complex driver is mapping this address region ? Please correct me if my understanding is wrong. Regards, Bharat This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately.