From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754967AbbJ0WU0 (ORCPT ); Tue, 27 Oct 2015 18:20:26 -0400 Received: from e19.ny.us.ibm.com ([129.33.205.209]:54199 "EHLO e19.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754087AbbJ0WUT (ORCPT ); Tue, 27 Oct 2015 18:20:19 -0400 X-IBM-Helo: d01dlp03.pok.ibm.com X-IBM-MailFrom: nacc@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org;sparclinux@vger.kernel.org Date: Tue, 27 Oct 2015 15:20:10 -0700 From: Nishanth Aravamudan To: David Miller Cc: willy@linux.intel.com, keith.busch@intel.com, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, aik@ozlabs.ru, david@gibson.dropbear.id.au, hch@infradead.org, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org Subject: Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA Message-ID: <20151027222010.GD7716@linux.vnet.ibm.com> References: <20151023205420.GA10197@linux.vnet.ibm.com> <20151026.182746.1323901353520152838.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151026.182746.1323901353520152838.davem@davemloft.net> X-Operating-System: Linux 3.13.0-40-generic (x86_64) User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15102722-0057-0000-0000-0000021F7800 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 26.10.2015 [18:27:46 -0700], David Miller wrote: > From: Nishanth Aravamudan > Date: Fri, 23 Oct 2015 13:54:20 -0700 > > > 1) add a generic dma_get_page_shift implementation that just returns > > PAGE_SHIFT > > I won't object to this patch series, but if I had implemented this I > would have required the architectures to implement this explicitly, > one-by-one. I think it is less error prone and more likely to end > up with all the architectures setting this correctly. Well, looks like I should spin up a v4 anyways for the powerpc changes. So, to make sure I understand your point, should I make the generic dma_get_page_shift a compile-error kind of thing? It will only fail on architectures that actually build the NVME driver (as the only caller). But I'm not sure how exactly to achieve that, if you could give a bit more detail I'd appreciate it! Thanks, Nish