[PATCH v12 4/5] dma-buf: heaps: Add CMA heap to dmabuf heaps

Andrew F. Davis afd at ti.com
Fri Oct 18 13:54:52 UTC 2019

On 10/18/19 8:03 AM, Benjamin Gaignard wrote:
> Le ven. 18 oct. 2019 à 13:21, Brian Starkey <Brian.Starkey at arm.com> a écrit :
>> 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 expose the
> cma heap.

"no-map" means it can't be used as a regular CMA either, we want some
way to both have it as a device usable CMA but also not be exposed to
userspace if needed.


> Benjamin
>> That'll teach me for reading my email in FIFO order.
>> This approach makes sense to me.
>> -Brian

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