From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH v6 4/5] dma-buf: heaps: Add CMA heap to dmabuf heaps
Date: Thu, 25 Jul 2019 05:50:14 -0700
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Cc: Christoph Hellwig <hch@infradead.org>, John Stultz <john.stultz@linaro.org>, lkml <linux-kernel@vger.kernel.org>, Laura Abbott <labbott@redhat.com>, Benjamin Gaignard <benjamin.gaignard@linaro.org>, Sumit Semwal <sumit.semwal@linaro.org>, Liam Mark <lmark@codeaurora.org>, Pratik Patel <pratikp@codeaurora.org>, Brian Starkey <Brian.Starkey@arm.com>, Vincent Donnefort <Vincent.Donnefort@arm.com>, Sudipto Paul <Sudipto.Paul@arm.com>, Xu YiPing <xuyiping@hisilicon.com>, "Chenfeng (puck)" <puck.chen@hisilicon.com>, butao <butao@hisilicon.com>, "Xiaqing (A)" <saberlily.xia@hisilicon.com>, Yudongbin <yudongbin@hisilicon.com>, Chenbo Feng <fengc@google.com>, Alistair Strachan <astrachan@google.com>, dri-devel <dri-devel@lists.freedesktop.org>
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On Wed, Jul 24, 2019 at 11:46:01AM -0400, Andrew F. Davis wrote:
> https://patchwork.kernel.org/patch/10863957/
> 
> It's actually a more simple heap type IMHO, but the logic inside is
> incompatible with the system/CMA heaps, if you move any of their code
> into the core framework then this heap stops working. Leading to out of
> tree hacks on the core to get it back functional. I see the same for the
> "complex" heaps with ION.

Well, this mostly is just another allocator (gen_pool).  And given that
the whole dma-buf infrastucture assumes things are backed by pages we
really shouldn't need much more than an alloc and a free callback (and
maybe the pgprot to map it) and handle the rest in common code.