Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754672AbbEZPpb (ORCPT ); Tue, 26 May 2015 11:45:31 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:23805 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751448AbbEZPp0 (ORCPT ); Tue, 26 May 2015 11:45:26 -0400 Message-ID: <556494D9.9090007@oracle.com> Date: Tue, 26 May 2015 11:44:25 -0400 From: Boris Ostrovsky User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Tomasz Nowicki , Hanjun Guo , Bjorn Helgaas , Arnd Bergmann , Catalin Marinas , Will Deacon , "Rafael J. Wysocki" CC: Jiang Liu , Liviu Dudau , Thomas Gleixner , Yijing Wang , Lorenzo Pieralisi , Suravee Suthikulpanit , Mark Salter , linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linaro-acpi@lists.linaro.org, Konrad Rzeszutek Wilk , Stefano Stabellini Subject: Re: [PATCH 10/11] XEN / PCI: Remove the dependence on arch x86 when PCI_MMCONFIG=y References: <1432644564-24746-1-git-send-email-hanjun.guo@linaro.org> <1432644564-24746-11-git-send-email-hanjun.guo@linaro.org> <55647B22.3010801@oracle.com> <55647C94.9080606@oracle.com> <5564893B.2070102@linaro.org> In-Reply-To: <5564893B.2070102@linaro.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: aserv0022.oracle.com [141.146.126.234] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3048 Lines: 86 On 05/26/2015 10:54 AM, Tomasz Nowicki wrote: > On 26.05.2015 16:00, Boris Ostrovsky wrote: >> On 05/26/2015 09:54 AM, Boris Ostrovsky wrote: >>> On 05/26/2015 08:49 AM, Hanjun Guo wrote: >>>> In drivers/xen/pci.c, there are arch x86 dependent codes when >>>> CONFIG_PCI_MMCONFIG is enabled, since CONFIG_PCI_MMCONFIG >>>> depends on ACPI, so this will prevent XEN PCI running on other >>>> architectures using ACPI with PCI_MMCONFIG enabled (such as ARM64). >>>> >>>> Fortunatly, it can be sloved in a simple way. In drivers/xen/pci.c, >>>> the only x86 dependent code is if ((pci_probe & PCI_PROBE_MMCONF) == >>>> 0), >>>> and it's defined in asm/pci_x86.h, the code means that >>>> if the PCI resource is not probed in PCI_PROBE_MMCONF way, just >>>> ingnore the xen mcfg init. Actually this is duplicate, because >>>> if PCI resource is not probed in PCI_PROBE_MMCONF way, the >>>> pci_mmconfig_list will be empty, and the if (list_empty()) >>>> after it will do the same job. >>>> >>>> So just remove the arch related code and the head file, this >>>> will be no functional change for x86, and also makes xen/pci.c >>>> usable for other architectures. >>>> >>>> Signed-off-by: Hanjun Guo >>>> CC: Konrad Rzeszutek Wilk >>>> CC: Boris Ostrovsky >>>> --- >>>> drivers/xen/pci.c | 6 ------ >>>> 1 file changed, 6 deletions(-) >>>> >>>> diff --git a/drivers/xen/pci.c b/drivers/xen/pci.c >>>> index 6785ebb..9a8dbe3 100644 >>>> --- a/drivers/xen/pci.c >>>> +++ b/drivers/xen/pci.c >>>> @@ -28,9 +28,6 @@ >>>> #include >>>> #include >>>> #include "../pci/pci.h" >>>> -#ifdef CONFIG_PCI_MMCONFIG >>>> -#include >>>> -#endif >>>> >>>> static bool __read_mostly pci_seg_supported = true; >>>> >>>> @@ -222,9 +219,6 @@ static int __init xen_mcfg_late(void) >>>> if (!xen_initial_domain()) >>>> return 0; >>>> >>>> - if ((pci_probe & PCI_PROBE_MMCONF) == 0) >>>> - return 0; >>>> - >>>> if (list_empty(&pci_mmcfg_list)) >>>> return 0; >>>> >>> >>> (+Stefano who is Xen ARM maintainer) >>> >>> This will not build on x86 since pci_mmcfg_list since, for example, >>> pci_mmcfg_list is declared in pci_x86.h. >> >> >> And now really with Stefano and with parsable first sentence, sorry: >> >> >> This will not build on x86 since pci_mmcfg_list, for example, is >> declared in pci_x86.h. > > With this patch set, not any more. Please see preceding patches. OK, I didn't notice this was part of a series. Then if not having PCI_PROBE_MMCONF bit set is indeed equivalent to list_empty(&pci_mmcfg_list), is there any reason for this flag to (continue to) exist? (and also for pci_mmcfg_arch_init_failed.) -boris -- 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/