Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754936AbZDHWhU (ORCPT ); Wed, 8 Apr 2009 18:37:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751895AbZDHWhE (ORCPT ); Wed, 8 Apr 2009 18:37:04 -0400 Received: from gw.goop.org ([64.81.55.164]:35885 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751997AbZDHWhC (ORCPT ); Wed, 8 Apr 2009 18:37:02 -0400 Message-ID: <49DD270A.6060506@goop.org> Date: Wed, 08 Apr 2009 15:36:58 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: FUJITA Tomonori CC: galak@kernel.crashing.org, hch@infradead.org, linux-kernel@vger.kernel.org, mingo@elte.hu, ian.campbell@citrix.com, beckyb@kernel.crashing.org Subject: Re: [PATCH 4/7] swiotlb: Allow arch override of address_needs_mapping References: <7366A4DE-6848-4AF6-AA33-6BD89B0A5153@kernel.crashing.org> <20090409061444G.fujita.tomonori@lab.ntt.co.jp> <49DD1D6B.6030001@goop.org> <20090409071032M.fujita.tomonori@lab.ntt.co.jp> In-Reply-To: <20090409071032M.fujita.tomonori@lab.ntt.co.jp> X-Enigmail-Version: 0.95.6 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1335 Lines: 33 FUJITA Tomonori wrote: >> Some architectures need non-trivial bus<->phys conversion routines, etc, >> > > Only Xen needs such conversion for swiotlb. > Becky's patches of last week also added __weak annotations to swiotlb_bus_to_virt, virt_to_bus and bus_to_phys; added the hwdev parameter to swiotlb_bus_to_phys; and added a weak swiotlb_arch_address_needs_mapping. I assume that was needed because powerpc needs non-trivial implementations for those functions. >> so either we can require it that all architectures wishing to use >> swiotlb define these functions, or have weak default functions that can >> be overridden by architectures where necessary. >> > > Can you give an example? I don't think IA64, X86_64 or POWER (which > will use swiotlb) need any __weak functions. If you say other archs > could use swiotlb, please tell me how they need these __weak. > As I said, Becky's patches added hooks in many of the places we added them for Xen. I assume that's because powerpc needs them; I have not seen the arch/powerpc side of those changes. J -- 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/