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From:   John Stultz <john.stultz@linaro.org>
Date:   Fri, 18 Oct 2019 11:29:29 -0700
Message-ID: <CALAqxLXwo=Pwi7BUXNzpk3-aqm1j+O9ZTi4NpYWdc2eYVK7t1w@mail.gmail.com>
Subject: Re: [PATCH v12 4/5] dma-buf: heaps: Add CMA heap to dmabuf heaps
To:     Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc:     Brian Starkey <Brian.Starkey@arm.com>,
        lkml <linux-kernel@vger.kernel.org>,
        Laura Abbott <labbott@redhat.com>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        Liam Mark <lmark@codeaurora.org>,
        Pratik Patel <pratikp@codeaurora.org>,
        Vincent Donnefort <Vincent.Donnefort@arm.com>,
        Sudipto Paul <Sudipto.Paul@arm.com>,
        "Andrew F . Davis" <afd@ti.com>,
        Christoph Hellwig <hch@infradead.org>,
        Chenbo Feng <fengc@google.com>,
        Alistair Strachan <astrachan@google.com>,
        Hridya Valsaraju <hridya@google.com>,
        Hillf Danton <hdanton@sina.com>,
        "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>,
        nd <nd@arm.com>
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On Fri, Oct 18, 2019 at 5:04 AM Benjamin Gaignard
<benjamin.gaignard@linaro.org> wrote:
> Le ven. 18 oct. 2019 =C3=A0 13:21, Brian Starkey <Brian.Starkey@arm.com> =
a =C3=A9crit :
> >
> > On Fri, Oct 18, 2019 at 05:23:22AM +0000, John Stultz wrote:
> > > This adds a CMA heap, which allows userspace to allocate
> > > a dma-buf of contiguous memory out of a CMA region.
> > >
> > > This code is an evolution of the Android ION implementation, so
> > > thanks to its original author and maintainters:
> > >   Benjamin Gaignard, Laura Abbott, and others!
> > >
> > > NOTE: This patch only adds the default CMA heap. We will enable
> > > selectively adding other CMA memory regions to the dmabuf heaps
> > > interface with a later patch (which requires a dt binding)
>
> Maybe we can use "no-map" DT property to trigger that. If set do not expo=
se the
> cma heap.

I don't think that's a good plan. See my WIP tree for the approach I'm plan=
ning:
  https://git.linaro.org/people/john.stultz/android-dev.git/log/?h=3Ddev/dm=
a-buf-heap-WIP

thanks
-john