Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965789AbaKNQDu (ORCPT ); Fri, 14 Nov 2014 11:03:50 -0500 Received: from service87.mimecast.com ([91.220.42.44]:42337 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965755AbaKNQDs convert rfc822-to-8bit (ORCPT ); Fri, 14 Nov 2014 11:03:48 -0500 Message-ID: <546627DD.2050200@arm.com> Date: Fri, 14 Nov 2014 16:03:41 +0000 From: Marc Zyngier User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130330 Thunderbird/17.0.5 MIME-Version: 1.0 To: Jiang Liu CC: Yijing Wang , Thomas Gleixner , Yijing Wang , Bjorn Helgaas , Ingo Molnar , "grant.likely@linaro.org" , Yingjoe Chen , Borislav Petkov , "H. Peter Anvin" , Matthias Brugger , Tony Luck , "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [Patch V1 0/6] Refine generic/PCI MSI irqodmian interfaces References: <1415879029-20098-1-git-send-email-jiang.liu@linux.intel.com> <54651BE2.9080008@arm.com> <54654C10.2040102@linux.intel.com> <54655632.2040209@huawei.com> <54655D44.1070703@linux.intel.com> <54660D7F.70702@gmail.com> <54661103.8000707@linux.intel.com> <54661CB8.2070704@arm.com> <54661ED9.8090901@linux.intel.com> In-Reply-To: <54661ED9.8090901@linux.intel.com> X-Enigmail-Version: 1.4.6 X-OriginalArrivalTime: 14 Nov 2014 16:03:42.0410 (UTC) FILETIME=[8FBD12A0:01D00024] X-MC-Unique: 114111416034406801 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 14/11/14 15:25, Jiang Liu wrote: > On 2014/11/14 23:16, Marc Zyngier wrote: >> On 14/11/14 14:26, Jiang Liu wrote: >>> On 2014/11/14 22:11, Yijing Wang wrote: >>>> >>> We have achieved 1 and 2. And seems we could also achieve 3 by >>> converting all arch specific PCI MSI code to use hierarchy >>> irqdomain. But not sure whether we could achieve 4, not familiar >>> with ARM world:) >> >> Killing all the weak functions shouldn't be a problem for ARM, we're >> trying very hard not to rely on them. >> >> Killing msi_chip is a different story, as this is what we use to match a >> PCI host controller with its MSI controller (that's what the of_node >> field in msi_chip is for). See drivers/of/of_pci.c for details. >> >> Also, we use msi_chip directly in the MSI drivers as a way to go from a >> pci_dev to the MSI controller specific structure: >> >> http://git.kernel.org/cgit/linux/kernel/git/maz/arm-platforms.git/tree/drivers/irqchip/irq-gic-v3-its.c?h=irq/stacked-its-v2#n1143 >> >> If we're going to kill msi_chip, we must make sure we have mechanisms >> that allow the conversion of the existing code. > Hi Marc, > Seem it doesn't worth the effort to remove irq_chip, > so I will focus on killing all weak functions first:) > After that, we may kill setup_irq and teardown_irq in irq_chip, > but seems irq_chip still has other usages, so I won't try to > kill irq_chip. I assume you mean msi_chip! ;-) Killing setup/teardown_irq is going to require some work. There are a few users in the tree (I can see three in drivers/pci/host and one in drivers/irqchip). Hopefully, we can get the maintainers to convert them. Thanks, M. -- Jazz is not dead. It just smells funny... -- 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/