Re: [RFC][PATCH 0/5 v2] DMA-BUF Heaps (destaging ION)

[Jerome Glisse]

On Tue, Mar 05, 2019 at 12:54:28PM -0800, John Stultz wrote:
> Here is a initial RFC of the dma-buf heaps patchset Andrew and I
> have been working on which tries to destage a fair chunk of ION
> functionality.
> 
> The patchset implements per-heap devices which can be opened
> directly and then an ioctl is used to allocate a dmabuf from the
> heap.
> 
> The interface is similar, but much simpler then IONs, only
> providing an ALLOC ioctl.
> 
> Also, I've provided simple system and cma heaps. The system
> heap in particular is missing the page-pool optimizations ION
> had, but works well enough to validate the interface.
> 
> I've booted and tested these patches with AOSP on the HiKey960
> using the kernel tree here:
>   https://git.linaro.org/people/john.stultz/android-dev.git/log/?h=dev/dma-buf-heap
> 
> And the userspace changes here:
>   https://android-review.googlesource.com/c/device/linaro/hikey/+/909436

What upstream driver will use this eventualy ? And why is it
needed ?

Cheers,
Jérôme