From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S932166AbaENLQ6 (ORCPT <rfc822;w@1wt.eu>);
	Wed, 14 May 2014 07:16:58 -0400
Received: from mail-ee0-f45.google.com ([74.125.83.45]:58350 "EHLO
	mail-ee0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1755043AbaENLQz (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Wed, 14 May 2014 07:16:55 -0400
From: Grant Likely <grant.likely@linaro.org>
Subject: Re: [PATCH v6 05/11] drivers: of: add automated assignment of
 reserved regions to client devices
To: "Jon Medhurst (Tixy)" <tixy@linaro.org>,
        Marek Szyprowski <m.szyprowski@samsung.com>
Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linaro-mm-sig@lists.linaro.org, devicetree@vger.kernel.org,
        linux-doc@vger.kernel.org, Mark Rutland <mark.rutland@arm.com>,
        Laura Abbott <lauraa@codeaurora.org>, Pawel Moll <pawel.moll@arm.com>,
        Arnd Bergmann <arnd@arndb.de>, Stephen Warren <swarren@wwwdotorg.org>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Tomasz Figa <t.figa@samsung.com>, Will Deacon <will.deacon@arm.com>,
        Tomasz Figa <tomasz.figa@gmail.com>,
        Michal Nazarewicz <mina86@mina86.com>, Marc <marc.ceeeee@gmail.com>,
        Nishanth Peethambaran <nishanth.p@gmail.com>,
        Rob Herring <robh+dt@kernel.org>, Paul Mackerras <paulus@samba.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Kumar Gala <galak@codeaurora.org>, Olof Johansson <olof@lixom.net>,
        Ian Campbell <ian.campbell@citrix.com>,
        Josh Cartwright <joshc@codeaurora.org>,
        Sascha Hauer <s.hauer@pengutronix.de>
In-Reply-To: <1400058938.3395.13.camel@linaro1.home>
References: <1393594976-16728-1-git-send-email-m.szyprowski@samsung.com>
	<1393594976-16728-6-git-send-email-m.szyprowski@samsung.com>
	<20140302054043.4F48AC414EF@trevor.secretlab.ca>
	<1400058938.3395.13.camel@linaro1.home>
Date: Wed, 14 May 2014 12:16:47 +0100
Message-Id: <20140514111647.BA6F6C4153D@trevor.secretlab.ca>
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed, 14 May 2014 10:15:38 +0100, "Jon Medhurst (Tixy)" <tixy@linaro.org> wrote:
> On Sun, 2014-03-02 at 13:40 +0800, Grant Likely wrote:
> > On Fri, 28 Feb 2014 14:42:50 +0100, Marek Szyprowski <m.szyprowski@samsung.com> wrote:
> > > This patch adds code for automated assignment of reserved memory regions
> > > to struct device. reserved_mem->ops->device_init()/device_cleanup()
> > > callbacks are called to perform reserved memory driver specific
> > > initialization and cleanup
> > > 
> > > Based on previous code provided by Josh Cartwright <joshc@codeaurora.org>
> > > 
> > > Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> > 
> > Hi Marek,
> > 
> > I've not applied this one yet, only because there is still the open
> > issue of whether or not these functions should be called from drivers or
> > from core code. I don't actually have any problems with the content of
> > this patch. Once the user is sorted out I'll merge it.
> 
> Has anything more come of these patches? I see some of the series is now
> in Linux 3.15, but the actual patches to let people use the feature
> aren't there yet, namely patches 5 though 8.
> 
> My personal immediate interest in these is as a mechanism on arm64 to
> limit CMA to a region of memory that is actually DMA-able devices (e.g.
> below 4GB for 32-bit devices without an iommu).
> 
> For reference, the mail archives for this series is at
> http://lkml.org/lkml/2014/2/28/237

IIRC, the issue I have with patch 5-8 is that I don't like the driver core
going off and doing automagical things to attach regions to devices.
I've not seen any more discussion on this topic since I merged the
patches I was okay with, but I may have missed something.

g.