Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Mon, 28 Jun 2021 15:49:55 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Rob Landley <rob@landley.net>
Cc:     Christoph Hellwig <hch@lst.de>,
        Yoshinori Sato <ysato@users.sourceforge.jp>,
        Rich Felker <dalias@libc.org>, linux-sh@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: dma_declare_coherent_memory and SuperH
Message-ID: <20210628134955.GA22559@lst.de>
References: <20210623133205.GA28589@lst.de> <1a55cf69-8fe1-dca0-68c7-f978567f9ca0@landley.net> <20210628133858.GA21602@lst.de> <4d6b7c35-f2fa-b476-b814-598a812770e6@landley.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <4d6b7c35-f2fa-b476-b814-598a812770e6@landley.net>
User-Agent: Mutt/1.5.17 (2007-11-01)
Precedence: bulk

On Mon, Jun 28, 2021 at 09:04:19AM -0500, Rob Landley wrote:
> > Well, the replacement is to declare the device memory carveouts in the
> > Device Tree.
> 
> Your plan is to eliminate the ability for non-device-tree boards to do DMA?

No.  My hope is to kill dma_declarare_coherent, an API for board
support files to declare device-specific regions to be used for
coherent DMA.