Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752945Ab2BAXgE (ORCPT ); Wed, 1 Feb 2012 18:36:04 -0500 Received: from mail-yw0-f46.google.com ([209.85.213.46]:36044 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751184Ab2BAXgC (ORCPT ); Wed, 1 Feb 2012 18:36:02 -0500 MIME-Version: 1.0 In-Reply-To: <20120131122339.GG32010@elte.hu> References: <20120121082857.GC32134@elte.hu> <20120121165830.GA9216@elte.hu> <20120131115855.5861bad7@pyramind.ukuu.org.uk> <20120131120922.GD32010@elte.hu> <20120131121820.58a1db97@pyramind.ukuu.org.uk> <20120131122339.GG32010@elte.hu> From: Linus Torvalds Date: Wed, 1 Feb 2012 15:35:41 -0800 X-Google-Sender-Auth: aS9Dsw2undneKkOHKG8Fok0hhJo Message-ID: Subject: Re: [PATCH] NVMe: Fix compilation on architecturs without readq/writeq To: Ingo Molnar Cc: Alan Cox , Hitoshi Mitake , Matthew Wilcox , Roland Dreier , Andrew Morton , James Bottomley , linux-kernel@vger.kernel.org, hpa@linux.intel.com Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 910 Lines: 23 On Tue, Jan 31, 2012 at 4:23 AM, Ingo Molnar wrote: > > non-atomic sounds good to me too. You both apparently missed the related discussion that some devices really do care about order, even if they don't care about atomicity. So we'd actually have two versions of the header file, one little-endian, and one big-endian. Then the driver that knows it doesn't need the atomic 'readq()' that is always defined, but wants a low-bytes-first version would just do #include (or "big-endian" if it wants to read/write high bits first). Most drivers probably don't care, but apparently NVMe does. Linus -- 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/