From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753813AbbFCIou (ORCPT ); Wed, 3 Jun 2015 04:44:50 -0400 Received: from mail-pa0-f42.google.com ([209.85.220.42]:34628 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753685AbbFCIoi (ORCPT ); Wed, 3 Jun 2015 04:44:38 -0400 Message-ID: <556EBE6D.90907@linaro.org> Date: Wed, 03 Jun 2015 16:44:29 +0800 From: Hanjun Guo User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: Lorenzo Pieralisi , Jiang Liu CC: "Rafael J . Wysocki" , Bjorn Helgaas , Marc Zyngier , Liviu Dudau , Yijing Wang , Catalin Marinas , Will Deacon , Lv Zheng , "lenb @ kernel . org" , LKML , "linux-pci@vger.kernel.org" , "linux-acpi@vger.kernel.org" , "x86 @ kernel . org" , "linux-arm-kernel@lists.infradead.org" , Arnd Bergmann Subject: Re: [Patch v4 5/8] ARM64/PCI/ACPI: Introduce struct pci_controller for ACPI References: <1433225576-8215-1-git-send-email-jiang.liu@linux.intel.com> <1433225576-8215-6-git-send-email-jiang.liu@linux.intel.com> <20150602093525.GA23543@red-moon> In-Reply-To: <20150602093525.GA23543@red-moon> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2015年06月02日 17:35, Lorenzo Pieralisi wrote: > On Tue, Jun 02, 2015 at 07:12:53AM +0100, Jiang Liu wrote: >> From: Hanjun Guo >> >> ARM64 ACPI based PCI host bridge init needs a arch dependent >> struct pci_controller to accommodate common PCI host bridge >> code which is introduced later, or it will lead to compile >> errors on ARM64. >> >> Signed-off-by: Hanjun Guo >> Tested-by: Suravee Suthikulpanit >> CC: Arnd Bergmann >> CC: Catalin Marinas >> CC: Liviu Dudau >> CC: Lorenzo Pieralisi >> CC: Will Deacon >> Signed-off-by: Jiang Liu >> --- >> arch/arm64/include/asm/pci.h | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h >> index b008a72f8bc0..70884957f253 100644 >> --- a/arch/arm64/include/asm/pci.h >> +++ b/arch/arm64/include/asm/pci.h >> @@ -10,6 +10,16 @@ >> #include >> #include >> >> +struct acpi_device; >> + >> +struct pci_controller { >> +#ifdef CONFIG_ACPI >> + struct acpi_device *companion; /* ACPI companion device */ >> +#endif >> + int segment; /* PCI domain */ >> + int node; /* NUMA node */ >> +}; > > There is nothing ARM64 specific in this structure. The only > reason I see you want to keep it arch specific is the iommu > pointer on x86, And also plarform_data for IA64 too. > but I think we should find a way to make > the common bits shared across archs (ie the struct above) and > add (maybe a void*) to the generic struct to cater for arch > specific data. > > Thoughts ? We discussed this already, it has limitations to make it common to all archs, I think the limitation are: - struct pci_controller are also used for other archs such as PowerPC and Tile, they will not use it for ACPI purpose, so we can not used for all archs. - if we let struct pci_controller defined only for archs using ACPI, such as introduce it in linux/acpi.h, we still can not satisfy that the struct pci_controller is not only used for ACPI case on x86, it will be used for non-ACPI too. So it's pretty difficult to share it with across archs to me, any more ideas? Thanks Hanjun