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=-5.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 5F95EC433DF for ; Tue, 25 Aug 2020 21:35:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A8272074A for ; Tue, 25 Aug 2020 21:35:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598391304; bh=iaxjbZsBqna2sELKvW37oDWjgc6W43k1NdwaMyPOzcQ=; h=Date:From:To:Cc:Subject:In-Reply-To:List-ID:From; b=V3tEHH+wcvqpWiXy/upCN/IJqVdr6lwi1g7kQ16FukcSiYNr3yr0q9MEFuUVerikR cpFLBdiWqpk6lfHFQ1NWSG05htrxSvV2Z9o79OpMYxEd3jQ4nU1mPEvMbP7rodvO1/ mAFjqlZ+cWZvdYGIiE3b7u/Q0uIGzCHRRyH9MDdQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726475AbgHYVfD (ORCPT ); Tue, 25 Aug 2020 17:35:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:38924 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726158AbgHYVfD (ORCPT ); Tue, 25 Aug 2020 17:35:03 -0400 Received: from localhost (104.sub-72-107-126.myvzw.com [72.107.126.104]) (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 431E0206EB; Tue, 25 Aug 2020 21:35:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598391302; bh=iaxjbZsBqna2sELKvW37oDWjgc6W43k1NdwaMyPOzcQ=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=ZDGaYc9qhTxV2pA1wPb9Q5LqI6Ehvpg5A4GMn18E+XiEAZR/80yPJKnZPFAK8TnIU wAM0ZPrbbpwoW2+6rUdZWmT9bIdSAFoL0FNWWLtzM8IoOFDxGQNXUB782s5cxX+YqV EyEgGHhTCo7adlpsp4Rg6JWQpAi01VHvK5gPVgNM= Date: Tue, 25 Aug 2020 16:35:01 -0500 From: Bjorn Helgaas To: Thomas Gleixner Cc: LKML , x86@kernel.org, Bjorn Helgaas , linux-pci@vger.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 , Lorenzo Pieralisi , Konrad Rzeszutek Wilk , xen-devel@lists.xenproject.org, Juergen Gross , Boris Ostrovsky , Stefano Stabellini , Marc Zyngier , Greg Kroah-Hartman , "Rafael J. Wysocki" , Megha Dey , Jason Gunthorpe , Dave Jiang , Alex Williamson , Jacob Pan , Baolu Lu , Kevin Tian , Dan Williams Subject: Re: [patch RFC 30/38] PCI/MSI: Allow to disable arch fallbacks Message-ID: <20200825213501.GA1931388@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87a6yixvnl.fsf@nanos.tec.linutronix.de> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Tue, Aug 25, 2020 at 11:28:30PM +0200, Thomas Gleixner wrote: > On Tue, Aug 25 2020 at 15:07, Bjorn Helgaas wrote: > >> + * The arch hooks to setup up msi irqs. Default functions are implemented > >> + * as weak symbols so that they /can/ be overriden by architecture specific > >> + * code if needed. > >> + * > >> + * They can be replaced by stubs with warnings via > >> + * CONFIG_PCI_MSI_DISABLE_ARCH_FALLBACKS when the architecture fully > >> + * utilizes direct irqdomain based setup. > > If not, it seems like it'd be nicer to have the burden on the arches > > that need/want to use arch-specific code instead of on the arches that > > do things generically. > > Right, but they still share the common code there and some of them > provide only parts of the weak callbacks. I'm not sure whether it's a > good idea to copy all of this into each affected architecture. > > Or did you just mean that those architectures should select > CONFIG_I_WANT_THE CRUFT instead of opting out on the fully irq domain > based ones? Yes, that was my real question -- can we confine the cruft in the crufty arches? If not, no big deal. Bjorn