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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,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 50765C433DF for ; Tue, 25 Aug 2020 21:28:36 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1EA0F20738 for ; Tue, 25 Aug 2020 21:28:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="tOoYjJYv"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="oQR1S/0D" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1EA0F20738 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id D3176875CD; Tue, 25 Aug 2020 21:28:35 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id WjloR6XFxI4T; Tue, 25 Aug 2020 21:28:35 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id 51402875D1; Tue, 25 Aug 2020 21:28:35 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 37062C07FF; Tue, 25 Aug 2020 21:28:35 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id E9C04C0051 for ; Tue, 25 Aug 2020 21:28:33 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id D8362875D1 for ; Tue, 25 Aug 2020 21:28:33 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id pcKEoiJR8Bbj for ; Tue, 25 Aug 2020 21:28:33 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by whitealder.osuosl.org (Postfix) with ESMTPS id 11D1B875CD for ; Tue, 25 Aug 2020 21:28:33 +0000 (UTC) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1598390910; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=DM8kbYiy7ZvYakB3fMHVSwg1j58bcLwh1sILIYH/AFI=; b=tOoYjJYvUPFZDmOguQPFJDhQeHuqRavvHi/bJrAyTkchveyhC+en4z3ohJa6FmPIHI2vow qc9HQ8/FTpaHEhGVpgURbiV1lVl+XKejxCXJmH2j3Sj2h8nwPHrrK3/Kb6Do9W3PTncSXY TOuqFSROfKTujH662yP4shxjPWBDkywHOauPnwUWRRiR+DHAaP2psLdtuzSJtmNFJD79PB hjeXftohGgS9rC9Xb2dZuw6mNwzd/d9QfmdUvlkZy88Ftt7fM3r9rWu4L7KrgJ8gocSx1K eGa2PZEjfsTIQ/LxJMcJsM3xNXGuHKDY89giMPP0/QzKHuUEf3bJ22fUusSPsg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1598390910; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=DM8kbYiy7ZvYakB3fMHVSwg1j58bcLwh1sILIYH/AFI=; b=oQR1S/0DMHh75hr94qI0low3SKHVQ7r24k+kTQlDcy/nGiegnvAQmFWoo65Pv64XBO7xgV AXir3AUyBr42qvBg== To: Bjorn Helgaas Subject: Re: [patch RFC 30/38] PCI/MSI: Allow to disable arch fallbacks In-Reply-To: <20200825200742.GA1924669@bjorn-Precision-5520> References: <20200825200742.GA1924669@bjorn-Precision-5520> Date: Tue, 25 Aug 2020 23:28:30 +0200 Message-ID: <87a6yixvnl.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Cc: Dimitri Sivanich , linux-hyperv@vger.kernel.org, Steve Wahl , linux-pci@vger.kernel.org, "K. Y. Srinivasan" , Dan Williams , Wei Liu , Stephen Hemminger , Baolu Lu , Marc Zyngier , x86@kernel.org, Jason Gunthorpe , Megha Dey , xen-devel@lists.xenproject.org, Kevin Tian , Konrad Rzeszutek Wilk , Haiyang Zhang , Alex Williamson , Stefano Stabellini , Bjorn Helgaas , Dave Jiang , Boris Ostrovsky , Jon Derrick , Juergen Gross , Russ Anderson , Greg Kroah-Hartman , LKML , iommu@lists.linux-foundation.org, Jacob Pan , "Rafael J. Wysocki" X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" 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. > > Do you expect *all* arches to eventually use direct irqdomain setup? Ideally that happens some day. We have five left when x86 is converted: IA64, MIPS, POWERPC, S390, SPARC IA64 is unlikely to be fixed, but might be solved naturally by removal. For the others I don't know, but it's not on the horizon anytime soon I fear. > And in that case, to remove the config option? Yes, and all the code which depends on it. > 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? Thanks, tglx _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu