From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5CC2CC433E6 for ; Fri, 28 Aug 2020 12:50:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 355742086A for ; Fri, 28 Aug 2020 12:50:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598619007; bh=Tmg6hNWVmQSJS0uP7afJ4MMWpAN7NReRjmWywe3CvWg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=qJkE/qPVctKEvt9WHK2YPxtPK+bJMvgztUqEWxOFVsbQ4lI2hKwAkrl/GjX3Yq56/ OM8SLk6xJpkAmTdFYO/dVJb6YJ2PtuQuhhqB/SELeTroRqaNPP4KVgsICHmF7yZsCP KAPapzPujQPFtUF93h2pCwRkUsMZcoB2tA3upvMw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729339AbgH1MuA (ORCPT ); Fri, 28 Aug 2020 08:50:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:51286 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729311AbgH1MsC (ORCPT ); Fri, 28 Aug 2020 08:48:02 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 623062086A; Fri, 28 Aug 2020 12:48:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598618881; bh=Tmg6hNWVmQSJS0uP7afJ4MMWpAN7NReRjmWywe3CvWg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=1+w8OFAyaU/aWlYarVXfqLN9fIBCmKiNEB0Jq48rpTVBQjoDoRWSuL+fHLBf6YsVQ 0jHKOc8fYAOkqjR2KhMCnoFrwVZYEYkuA5zRP2QSVxlGQweX4oXyTrY5Fp6mL5LaJq JXGC+7f0QfgyXvjiWKhAg1/Bko+ABpmHB9iTJxFE= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1kBdnT-007Pl5-Sa; Fri, 28 Aug 2020 13:48:00 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Fri, 28 Aug 2020 13:47:59 +0100 From: Marc Zyngier To: Jason Gunthorpe Cc: Lorenzo Pieralisi , Bjorn Helgaas , Thomas Gleixner , LKML , x86@kernel.org, Joerg Roedel , iommu@lists.linux-foundation.org, linux-hyperv@vger.kernel.org, Haiyang Zhang , Jon Derrick , Lu Baolu , Wei Liu , "K. Y. Srinivasan" , Stephen Hemminger , Steve Wahl , Dimitri Sivanich , Russ Anderson , linux-pci@vger.kernel.org, Bjorn Helgaas , Konrad Rzeszutek Wilk , xen-devel@lists.xenproject.org, Juergen Gross , Boris Ostrovsky , Stefano Stabellini , Greg Kroah-Hartman , "Rafael J. Wysocki" , Megha Dey , Dave Jiang , Alex Williamson , Jacob Pan , Baolu Lu , Kevin Tian , Dan Williams , Rob Herring Subject: Re: [patch V2 34/46] PCI/MSI: Make arch_.*_msi_irq[s] fallbacks selectable In-Reply-To: <20200828121944.GQ1152540@nvidia.com> References: <20200826112333.992429909@linutronix.de> <20200827182040.GA2049623@bjorn-Precision-5520> <20200828112142.GA14208@e121166-lin.cambridge.arm.com> <20200828121944.GQ1152540@nvidia.com> User-Agent: Roundcube Webmail/1.4.8 Message-ID: <0cc8bfd9258dfc507585fd0f19a945e3@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: jgg@nvidia.com, lorenzo.pieralisi@arm.com, helgaas@kernel.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, x86@kernel.org, joro@8bytes.org, iommu@lists.linux-foundation.org, linux-hyperv@vger.kernel.org, haiyangz@microsoft.com, jonathan.derrick@intel.com, baolu.lu@linux.intel.com, wei.liu@kernel.org, kys@microsoft.com, sthemmin@microsoft.com, steve.wahl@hpe.com, sivanich@hpe.com, rja@hpe.com, linux-pci@vger.kernel.org, bhelgaas@google.com, konrad.wilk@oracle.com, xen-devel@lists.xenproject.org, jgross@suse.com, boris.ostrovsky@oracle.com, sstabellini@kernel.org, gregkh@linuxfoundation.org, rafael@kernel.org, megha.dey@intel.com, dave.jiang@intel.com, alex.williamson@redhat.com, jacob.jun.pan@intel.com, baolu.lu@intel.com, kevin.tian@intel.com, dan.j.williams@intel.com, robh@kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi Jason, On 2020-08-28 13:19, Jason Gunthorpe wrote: > On Fri, Aug 28, 2020 at 12:21:42PM +0100, Lorenzo Pieralisi wrote: >> On Thu, Aug 27, 2020 at 01:20:40PM -0500, Bjorn Helgaas wrote: >> >> [...] >> >> > And I can't figure out what's special about tegra, rcar, and xilinx >> > that makes them need it as well. Is there something I could grep for >> > to identify them? Is there a way to convert them so they don't need >> > it? >> >> I think DT binding and related firmware support are needed to setup >> the >> MSI IRQ domains correctly, there is nothing special about tegra, rcar >> and xilinx AFAIK (well, all native host controllers MSI handling is >> *special* just to be polite but let's gloss over this for the time >> being). >> >> struct msi_controller, to answer the first question. >> >> I have doubts about pci_mvebu too, they do allocate an msi_controller >> but without methods so it looks pretty much useless. > > Oh, I did once know things about mvebu.. > > I suspect the msi controller pointer assignment is dead code at this > point. The only implementation of MSI with that PCI root port is > drivers/irqchip/irq-armada-370-xp.c which looks like it uses > irq_domain. > > Actually looks like things are very close to eliminating > msi_controller. > > This is dead code, can't find a setter for hw_pci->msi_ctrl: > > arch/arm/include/asm/mach/pci.h: struct msi_controller > *msi_ctrl; > arch/arm/kernel/bios32.c: bridge->msi = > hw->msi_ctrl; > > This is probably just copying NULL from one place to another: > > drivers/pci/controller/pci-mvebu.c: struct msi_controller *msi; > > These need conversion to irq_domain (right?): > > drivers/pci/controller/pci-hyperv.c: struct msi_controller msi_chip; > drivers/pci/controller/pci-tegra.c: struct msi_controller chip; > drivers/pci/controller/pcie-rcar-host.c: struct msi_controller > chip; > drivers/pci/controller/pcie-xilinx.c:static struct msi_controller > xilinx_pcie_msi_chip = { > > Then the stuff in drivers/pci/msi.c can go away. > > So the arch_setup_msi_irq/etc is not really an arch hook, but some > infrastructure to support those 4 PCI root port drivers. I happen to have a *really old* patch addressing Tegra [1], which I was never able to test (no HW). Rebasing it shouldn't be too hard, and maybe you can find someone internally willing to give it a spin? That'd be a good start towards the removal of this cruft. Thanks, M. [1] https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/commit/?h=irq/kill-msi-controller&id=83b3602fcee7972b9d549ed729b56ec28de16081 -- Jazz is not dead. It just smells funny...