From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752987AbcGOIdo (ORCPT ); Fri, 15 Jul 2016 04:33:44 -0400 Received: from mout.kundenserver.de ([212.227.126.134]:52549 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752948AbcGOIdi (ORCPT ); Fri, 15 Jul 2016 04:33:38 -0400 From: Arnd Bergmann To: linux-arm-kernel@lists.infradead.org Cc: Bharat Kumar Gogada , "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" , Bjorn Helgaas , nofooter , "Liviu.Dudau@arm.com" Subject: Re: Memory and IO space Enabling different in x86 and ARM64 Date: Fri, 15 Jul 2016 10:33:06 +0200 Message-ID: <7127812.WYSppNUyGc@wuerfel> User-Agent: KMail/5.1.3 (Linux/4.4.0-28-generic; KDE/5.18.0; x86_64; ; ) In-Reply-To: <8520D5D51A55D047800579B094147198258B9376@XAP-PVEXMBX01.xlnx.xilinx.com> References: <8520D5D51A55D047800579B094147198258B9376@XAP-PVEXMBX01.xlnx.xilinx.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:u5LAyWpTQED8FdOhyAA87Ekic83FufpQg+adSp1e7YxMePJP46I 6Oenu3yLjQYFsAZOOHNO+418xrxHri1fw9finpOW5O2lN2dZKV9Agvlu/SyKR9rkCY22HPx FDyIT4RKD+7xteH/+413z7k/TFh9vpO4qtNqjSKrBOMJPjS1zbOCLxpiaFiyUENySWkXlM/ OPe+yNmCi1ulyTeD4K7jA== X-UI-Out-Filterresults: notjunk:1;V01:K0:cJ2IDrhERY4=:czNDNhIoW46ljBGOpgD1xZ mZHaad3oidDK+ZxnPDvOsvwaGl/IIqbcKi9d+7AcZSGzYUFW49w5PHIT5HbrBXPHrnQqq7xmn gr4ITmgRhPTnyu3DFMHPRxDzejiiIuCavqMvVzNLNJyM+6/Xwe8oCnnmyyp9Rlv5u0k6N7dwt aUDTV0FhdSjYTyfMoD0Vvm9b9jitCW/x3or0+NAP4Rh5Lwh3ypjXyWk0YZ813LAP8HlM9dzKu LX4nN3/8Cj6vo3W17Ar6ezoP9FS7z/da2ubPzVRKPCQoOe4NPJZPZ2ecy9I5nAwD5NrhkwF55 x7MP36Ggg699oQYNnT58NGyy9nFOkO0L+yVXzhdxMU1IsdQG9d22bCTKgJWnJO0E0iqxJUbHd Gax+uws/d5WOMD/r8Sj1GZO04V0DifF5TQWwprObQb8JB79AN4qsGNJQpAAlpUeGh9QxbFSNF CgWGOfO44RbLUgVMHYGP1OQnVRFAiv/uin3OUNVQmV50o74SFERER/6hxtmsux1YbTygEROwr es6LsHh9089Y6EpC3NHQS/pIoKJwle1bBO/qpDoEUTt0pch3JDYWw8s2sHZRnbaD8pljKjst3 PK+JgdxYpvAgBtAc5xXbosw3C3Slxl8TngDSj/DNdeuwcjW1QHMFK69AeCtap5Ts/J6MUxRYA b6999pV1EIFKUrQesoN9paOZwbDf5dyEqUIKImR0ERqdr7TeG2qO+7dV7Wtnqf5AzbEYGlcPX +AK8oFYCPcHjnnMz Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday, July 15, 2016 8:29:49 AM CEST Bharat Kumar Gogada wrote: > I observe that memory and IO space are enabled by BIOS in x86. > > In ARM64 we need to call pci_enable_device form End Point to enable these resources. > > Why the resource enablement is different in x86 and ARM64 ? > > Please correct me if my observation is wrong. This is a difference between systems with a BIOS and embedded systems with a plain bootloader that ignores PCI. On an ARM64 server system with UEFI you should expect the device to be usable too, but on an embedded system, Linux takes the role of the BIOS. Arnd