From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <benh@kernel.crashing.org>
Received: from gate.crashing.org (gate.crashing.org [63.228.1.57])
	(using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
	(Client did not present a certificate)
	by ozlabs.org (Postfix) with ESMTPS id C40EDB6F9B
	for <linuxppc-dev@lists.ozlabs.org>;
	Thu,  1 Sep 2011 15:35:39 +1000 (EST)
Subject: Re: [PATCH 2/4] dma-mapping: add get_required_mask if arch
	overrides default
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
In-Reply-To: <20110629171304B.fujita.tomonori@lab.ntt.co.jp>
References: <1308942325-4813-1-git-send-email-nacc@us.ibm.com>
	<1308942325-4813-3-git-send-email-nacc@us.ibm.com>
	<20110629171304B.fujita.tomonori@lab.ntt.co.jp>
Content-Type: text/plain; charset="UTF-8"
Date: Thu, 01 Sep 2011 15:35:11 +1000
Message-ID: <1314855311.4145.8.camel@pasglop>
Mime-Version: 1.0
Cc: vinod.koul@intel.com, linux-kernel@vger.kernel.org, miltonm@bga.com,
	nacc@us.ibm.com, dan.j.williams@intel.com, linuxppc-dev@lists.ozlabs.org
List-Id: Linux on PowerPC Developers Mail List <linuxppc-dev.lists.ozlabs.org>
List-Unsubscribe: <https://lists.ozlabs.org/options/linuxppc-dev>,
	<mailto:linuxppc-dev-request@lists.ozlabs.org?subject=unsubscribe>
List-Archive: <http://lists.ozlabs.org/pipermail/linuxppc-dev>
List-Post: <mailto:linuxppc-dev@lists.ozlabs.org>
List-Help: <mailto:linuxppc-dev-request@lists.ozlabs.org?subject=help>
List-Subscribe: <https://lists.ozlabs.org/listinfo/linuxppc-dev>,
	<mailto:linuxppc-dev-request@lists.ozlabs.org?subject=subscribe>

On Wed, 2011-06-29 at 17:19 +0900, FUJITA Tomonori wrote:
> On Fri, 24 Jun 2011 12:05:23 -0700
> Nishanth Aravamudan <nacc@us.ibm.com> wrote:
> 
> > From: Milton Miller <miltonm@bga.com>
> > 
> > If an architecture sets ARCH_HAS_DMA_GET_REQUIRED_MASK and has settable
> > dma_map_ops, the required mask may change by the ops implementation.
> > For example, a system that always has an mmu inline may only require 32
> > bits while a swiotlb would desire bits to cover all of memory.
> > 
> > Therefore add the field if the architecture does not use the generic
> > definition of dma_get_required_mask. The first use will by by powerpc.
> > Note that this does add some dependency on the order in which files are
> > visible here.

 .../...

> If you add get_required_mask to dma_map_ops, we should clean up ia64
> too and implement the generic proper version in
> dma-mapping-common.h. Then we kill ARCH_HAS_DMA_GET_REQUIRED_MASK
> ifdef hack. Otherwise, I don't think it makes sense to add this to
> dma_map_ops.

In the meantime, can I have an ack so I can include this along with the
rest of Milton's patches ? It's been around for a while now :-)

I'm a bit late for producing a powerpc-next (due to travelling).

Cheers,
Ben.