[PATCH v4 3/7] accel/ivpu: Add GEM buffer object management

[Andrew Davis]

On 1/9/23 5:47 AM, Jacek Lawrynowicz wrote:
> Hi,
> 
> On 06.01.2023 14:29, Stanislaw Gruszka wrote:
>> Hi
>>
>> On Thu, Jan 05, 2023 at 12:46:51PM -0600, Andrew Davis wrote:
>>> On 12/8/22 5:07 AM, Jacek Lawrynowicz wrote:
>>>> Adds four types of GEM-based BOs for the VPU:
>>>>     - shmem
>>>>     - userptr
>>>
>>> Do you have some specific need for userptr that would not
>>> be covered by prime import + heaps? I'm just trying to get
>>> a feel for the typical use-cases for these.
>>
>> Honestly, I'm not sure. I think we have use-cases that justify
>> adding userptr, but have to check with our team members that
>> better understand the requirements.
> 
> It would be great if userptr could be replaced by dma-buf heaps.
> I will add this to TODO and we will look into this after the driver is merged.
> 

We should also be clear on the export capabilities up front
for these kinds of drivers. DRM allows re-exporting as DMA-BUF
no matter the allocation style/location which has caused issues.
Lets start accel framework with the rule that if you want a shareable
buffer you should allocate it from Heaps not the driver, then pass
it into the driver.

Merging as-is to save churn now would be fine, but it must be clear
that this is not a stable ABI just because it was allowed to be
merged. userptr/export will be removed later and should not be used
by the userspace driver.

Andrew

> Regards,
> Jacek