Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755820Ab2BFSzS (ORCPT ); Mon, 6 Feb 2012 13:55:18 -0500 Received: from mail-gy0-f174.google.com ([209.85.160.174]:56341 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752841Ab2BFSzP convert rfc822-to-8bit (ORCPT ); Mon, 6 Feb 2012 13:55:15 -0500 MIME-Version: 1.0 In-Reply-To: References: <1328425088-6562-1-git-send-email-yinghai@kernel.org> <1328425088-6562-2-git-send-email-yinghai@kernel.org> Date: Mon, 6 Feb 2012 10:55:14 -0800 X-Google-Sender-Auth: KkdUYbwMVi50277nOpVas280vNA Message-ID: Subject: Re: [PATCH 01/24] PCI: Add iobusn_resource From: Yinghai Lu To: Bjorn Helgaas Cc: Jesse Barnes , Benjamin Herrenschmidt , Tony Luck , Dominik Brodowski , Andrew Morton , Linus Torvalds , Greg Kroah-Hartman , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1595 Lines: 40 On Mon, Feb 6, 2012 at 10:48 AM, Bjorn Helgaas wrote: >> +struct resource iobusn_resource = { >> + ? ? ? .name ? = "PCI busn", >> + ? ? ? .start ?= 0, >> + ? ? ? .end ? ?= 0xffffff, >> + ? ? ? .flags ?= IORESOURCE_BUS, >> +}; > > I'm not sure this should be global. ?iomem_resource and > ioport_resource *are* really global, because they refer to processor > address space that is the same for everybody. ?But PCI bus numbers are > specific to PCI. ?Some machines don't have PCI at all, and there are > different bus architectures to which this doesn't apply. that does not hurt them. > > The 0-0xffffff range is misleading because it includes both the domain > and the bus number, and it's meaningless to allocate ranges that cross > domain boundaries. ?For example, [bus 0x0000f0-0x000120] includes bus > numbers from domain 0000 and domain 0001, which doesn't make any sense > because a bus can only be in one domain. allocation code will make sure it will be cross the boundary for domain. > > I think it would make more sense to keep this bus number resource in a > per-host bridge structure. ?Then we wouldn't need to include the > domain number at all because the host bridge determines the domain. not sure. insert the all busn_res of all peer root buses into one global iobusn_resource looks more simple. Yinghai -- 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/