From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: [PATCH v2 00/18] Cross-architecture definitions of relaxed MMIO accessors Date: Wed, 28 May 2014 06:23:30 +1000 Message-ID: <1401222210.20915.79.camel@pasglop> References: <1400777250-17335-1-git-send-email-will.deacon@arm.com> <1401054470.3958.30.camel@pasglop> <20140527193425.GC30751@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from gate.crashing.org ([63.228.1.57]:53938 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751186AbaE0U31 (ORCPT ); Tue, 27 May 2014 16:29:27 -0400 In-Reply-To: <20140527193425.GC30751@arm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Will Deacon Cc: "linux-arch@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "arnd@arndb.de" , "monstr@monstr.eu" , "dhowells@redhat.com" , "broonie@linaro.org" , "peterz@infradead.org" , "paulmck@linux.vnet.ibm.com" On Tue, 2014-05-27 at 20:34 +0100, Will Deacon wrote: > Do you mean the io{read,write} functions? Funnily enough, they're already > relaxed on ARM if you go by the semantics I've proposed. That implies we at > least need some Documentation to that effect... > > What do you do on ppc? They are not supposed to be relaxed. If they are, you probably have a whole lot of busted drivers :-) They have the same semantics as readl/writel for memory and as inb/outb for IO space, they just allow to hide the "type" (memory vs. IO) from most of the driver code. We probably need to create a set of _relaxed variants. Cheers, Ben.