From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756623AbbJ2Lzr (ORCPT ); Thu, 29 Oct 2015 07:55:47 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:44642 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756176AbbJ2Lzq (ORCPT ); Thu, 29 Oct 2015 07:55:46 -0400 Date: Thu, 29 Oct 2015 04:55:36 -0700 From: Christoph Hellwig To: "Busch, Keith" Cc: David Miller , aik@ozlabs.ru, mpe@ellerman.id.au, nacc@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, hch@infradead.org, paulus@samba.org, benh@kernel.crashing.org, sparclinux@vger.kernel.org, willy@linux.intel.com, linuxppc-dev@lists.ozlabs.org, david@gibson.dropbear.id.au Subject: Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA Message-ID: <20151029115536.GA28090@infradead.org> References: <20151026.182746.1323901353520152838.davem@davemloft.net> <20151027222010.GD7716@linux.vnet.ibm.com> <20151027223643.GA25332@localhost.localdomain> <20151027.175443.140992924519172506.davem@davemloft.net> <20151028135922.GA27909@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151028135922.GA27909@localhost.localdomain> User-Agent: Mutt/1.5.23 (2014-03-12) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 28, 2015 at 01:59:23PM +0000, Busch, Keith wrote: > The "new" interface for all the other architectures is the same as the > old one we've been using for the last 5 years. > > I welcome x86 maintainer feedback to confirm virtual and DMA addresses > have the same offset at 4k alignment, but I have to insist we don't > break my currently working hardware to force their attention. We had a quick cht about this issue and I think we simply should default to a NVMe controler page size of 4k everywhere as that's the safe default. This is also what we do for RDMA Memory reigstrations and it works fine there for SRP and iSER.