Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752902AbbH1Vjw (ORCPT ); Fri, 28 Aug 2015 17:39:52 -0400 Received: from mga11.intel.com ([192.55.52.93]:33011 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752662AbbH1Vjv (ORCPT ); Fri, 28 Aug 2015 17:39:51 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,427,1437462000"; d="scan'208";a="634253129" Date: Fri, 28 Aug 2015 21:39:49 +0000 (UTC) From: Keith Busch X-X-Sender: vmware@localhost.lm.intel.com To: Thomas Gleixner cc: Keith Busch , x86@kernel.org, LKML , Bryan Veal , Dan Williams , linux-pci@vger.kernel.org, Jiang Liu Subject: Re: [RFC PATCH 1/2] x86: PCI bus specific MSI operations In-Reply-To: Message-ID: References: <1440715146-16578-1-git-send-email-keith.busch@intel.com> <1440715146-16578-2-git-send-email-keith.busch@intel.com> User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1313 Lines: 27 On Fri, 28 Aug 2015, Thomas Gleixner wrote: > On Thu, 27 Aug 2015, Keith Busch wrote: > >> This patch adds struct x86_msi_ops to x86's PCI sysdata. This gives a >> host bridge driver the option to provide alternate MSI Data Register >> and MSI-X Table Entry programming for devices in PCI domains that do >> not subscribe to usual "IOAPIC" format. > > I'm not too fond about more ad hoc indirection and special casing. We > should be able to handle this with hierarchical irq domains. Jiang > might have an idea how to do that for your case. Thank you for the suggestion, I will take a closer look at this again. All the better if we don't require an arch specific dependency. I asked Jiang about domain hierarchies a few weeks ago and understood these are suited for irq controllers, but the VMD device is an aggregator. Here's a little more h/w info in case it helps steer me in the right direction: VMD muxes all the device interrupts in its PCI domain into one of several VMD h/w irqs. The VMD driver then has to de-mux that into CPU side irqs for each device. -- 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/