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Date:   Tue, 25 Jun 2019 08:32:28 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Geert Uytterhoeven <geert@linux-m68k.org>
Cc:     Christoph Hellwig <hch@lst.de>, Greg Ungerer <gerg@linux-m68k.org>,
        linux-m68k <linux-m68k@lists.linux-m68k.org>,
        Linux IOMMU <iommu@lists.linux-foundation.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [RFC] switch m68k to use the generic remapping DMA allocator
Message-ID: <20190625063228.GA29561@lst.de>
References: <20190614102126.8402-1-hch@lst.de> <CAMuHMdVPU5RQyX4FnHFEhxXZeG3v0uh_-t2FB=vAzQ8_3u-gSw@mail.gmail.com>
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On Mon, Jun 17, 2019 at 08:53:55PM +0200, Geert Uytterhoeven wrote:
> Hi Christoph,
> 
> On Fri, Jun 14, 2019 at 12:21 PM Christoph Hellwig <hch@lst.de> wrote:
> > can you take a look at the (untested) patches below?  They convert m68k
> > to use the generic remapping DMA allocator, which is also used by
> > arm64 and csky.
> 
> Thanks. But what does this buy us?

A common dma mapping code base with everyone, including supporting
DMA allocations from atomic context, which the documentation and
API assume are there, but which don't work on m68k.

> bloat-o-meter says:
> 
> add/remove: 75/0 grow/shrink: 11/6 up/down: 4122/-82 (4040)

What do these values stand for?  The code should grow a little as
we now need to include the the pool allocator for the above API
fix.