From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934791AbYETW1r (ORCPT ); Tue, 20 May 2008 18:27:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762111AbYETW1g (ORCPT ); Tue, 20 May 2008 18:27:36 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:44566 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932668AbYETW1f (ORCPT ); Tue, 20 May 2008 18:27:35 -0400 Date: Tue, 20 May 2008 23:15:16 +0100 From: Alan Cox To: Scott Wood Cc: benh@kernel.crashing.org, Trent Piepho , linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] [POWERPC] Improve (in|out)_beXX() asm code Message-ID: <20080520231516.76b924a2@core> In-Reply-To: <483344C0.3020703@freescale.com> References: <1211316025-29069-1-git-send-email-tpiepho@freescale.com> <1211318219.8297.177.camel@pasglop> <483344C0.3020703@freescale.com> X-Mailer: Claws Mail 3.3.1 (GTK+ 2.12.5; x86_64-redhat-linux-gnu) Organization: Red Hat UK Cyf., Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, Y Deyrnas Gyfunol. Cofrestrwyd yng Nghymru a Lloegr o'r rhif cofrestru 3798903 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > It looks like we rely on -fno-strict-aliasing to prevent reordering > ordinary memory accesses (such as to DMA descriptors) past the I/O DMA descriptors in main memory are dependant on cache behaviour anyway and the dma_* operators should be the ones enforcing the needed behaviour. Alan