From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Cox Subject: Re: MMIO and gcc re-ordering issue Date: Tue, 27 May 2008 22:38:22 +0100 Message-ID: <20080527223822.57306677@core> References: <1211852026.3286.36.camel@pasglop> <20080526.184047.88207142.davem@davemloft.net> <1211854540.3286.42.camel@pasglop> <20080526.192812.184590464.davem@davemloft.net> <1211859542.3286.46.camel@pasglop> <1211922621.3286.80.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:57401 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758296AbYE0Vw0 (ORCPT ); Tue, 27 May 2008 17:52:26 -0400 In-Reply-To: Sender: linux-arch-owner@vger.kernel.org List-ID: To: Linus Torvalds Cc: Benjamin Herrenschmidt , David Miller , linux-arch@vger.kernel.org, scottwood@freescale.com, linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, tpiepho@freescale.com > re-ordering, even though I doubt it will be visible in practice. So if you > use the "__" versions, you'd better have barriers even on x86! Are we also going to have __ioread*/__iowrite* ? Also is the sematics of __readl/__writel defined for all architectures - I used it ages ago in the i2o drivers for speed and it got removed because it didn't build on some platforms. Alan