From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com ([217.140.101.70]:39687 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752687AbcGAPky (ORCPT ); Fri, 1 Jul 2016 11:40:54 -0400 Date: Fri, 1 Jul 2016 16:40:46 +0100 From: Liviu Dudau To: Arnd Bergmann Cc: Thierry Reding , Bjorn Helgaas , Tomasz Nowicki , linux-pci@vger.kernel.org, linux-tegra@vger.kernel.org Subject: Re: [PATCH v2 1/2] PCI: Add new method for registering PCI hosts Message-ID: <20160701154046.GE8609@e106497-lin.cambridge.arm.com> References: <20160630151931.29216-1-thierry.reding@gmail.com> <6212651.41bebQZ9BM@wuerfel> <20160701145244.GD8609@e106497-lin.cambridge.arm.com> <14945085.QO6LcyFgTY@wuerfel> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: <14945085.QO6LcyFgTY@wuerfel> Sender: linux-pci-owner@vger.kernel.org List-ID: On Fri, Jul 01, 2016 at 05:17:11PM +0200, Arnd Bergmann wrote: > On Friday, July 1, 2016 3:52:44 PM CEST Liviu Dudau wrote: > > > > > > > > or do you mean we should have extra alignment in there so the > > > private pointer has a minimum alignment higher than the > > > alignment of struct pci_host_bridge? > > > > but this ^. bridge pointer arithmetic means +1 is not necessarily +sizeof(struct pci_host_bridge) > > bytes. AFAIK that can be rounded to the nearest natural alignment for pointers on that > > architecture. > > No, that's not how it works. Really? If struct foo takes 31 bytes, and struct foo *p = (struct foo*)64, what's p's value after p++ ? 95? I thought the compiler is allowed to consider the structure padded so that p++ is 96. > > > > I'm absolutely fine with any of those suggestions, whichever > > > makes the nicest API. > > > > Does anyone need to subclass the pci_host_bridge structure? And is appending data right > > after the structure useful? > > I was basically following the way alloc_etherdev() and a lot of other > subsystems handle it. Probably valid if casted to char* ? Liviu > > Arnd > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯