Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754047AbbFUOkG (ORCPT ); Sun, 21 Jun 2015 10:40:06 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:36425 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751911AbbFUOj7 (ORCPT ); Sun, 21 Jun 2015 10:39:59 -0400 MIME-Version: 1.0 In-Reply-To: <20150621135606.GB9572@lst.de> References: <20150617235209.12943.24419.stgit@dwillia2-desk3.amr.corp.intel.com> <20150617235508.12943.25057.stgit@dwillia2-desk3.amr.corp.intel.com> <20150621100535.GB5915@lst.de> <20150621135606.GB9572@lst.de> Date: Sun, 21 Jun 2015 07:39:58 -0700 Message-ID: Subject: Re: [PATCH 04/15] libnvdimm, nfit, nd_blk: driver for BLK-mode access persistent memory From: Dan Williams To: Christoph Hellwig Cc: Jens Axboe , "linux-nvdimm@lists.01.org" , Boaz Harrosh , "Kani, Toshimitsu" , "Rafael J. Wysocki" , "linux-kernel@vger.kernel.org" , Andy Lutomirski , Jens Axboe , Linux ACPI , "H. Peter Anvin" , linux-fsdevel , Ross Zwisler , Ingo Molnar Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1106 Lines: 24 On Sun, Jun 21, 2015 at 6:56 AM, Christoph Hellwig wrote: > On Sun, Jun 21, 2015 at 06:31:38AM -0700, Dan Williams wrote: >> > As mentioned last time only arch asm/ headers may include asm-generic >> > headers. >> >> No, not in this case, there's no other way to define readq()/writeq() >> on 32-bit builds. See: > > Oh my god. I think we're both right: no driver should use asm-generic, > but because someone totally messed this abstraction up you have no choice. > > We really should have a linux/*.h header for these that just does the > right thing. > > Btw, what's the reason you're using the hi-lo ordering unlikely everyone > else? IMHO that should be an arch and not a driver choice. If the hardware latches the register on writing the hi or lo bits first then it matters, otherwise it's arbitrary like it is in this case. It's hard to have an arch default because different devices care about different orderings, so it must be a driver choice afaics. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/