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

[Daniel Vetter <daniel@ffwll.ch>]

On Fri, 6 Jan 2023 at 14:23, Stanislaw Gruszka
<stanislaw.gruszka@linux.intel.com> wrote:
>
> On Fri, Jan 06, 2023 at 11:50:05AM +0100, Daniel Vetter wrote:
> > On Thu, Dec 08, 2022 at 12:07:29PM +0100, Jacek Lawrynowicz wrote:
> > > Adds four types of GEM-based BOs for the VPU:
> > >   - shmem
> > >   - userptr
> > >   - internal
> >
> > Uh what do you need this for? Usually the way we do these is just alloce a
> > normal bo, and then pin them.
>
> I think we do alloc/pin this way, but all our bo's are GEM based.
> For those bo's we use internally and other non-shmem we create them
> with drm_gem_private_object_init(). I think this way is simpler than
> have separate code for non-GEM and GEM bo's ...

They should be all gem bo, I guess you mean shmem vs non-shmem? And
the allocate+pin is the standard approach for drivers that have
somewhat dynamic bo (i.e. not using dma_alloc) and need some of them
(hopefully only for driver internal objects, not for userspace) pinned
in place. So you handrolling a perma-pinned gem bo for internal
objects is rather strange by drm driver standards.

> > Also, gem shmem helpers should be able to mostly cover you here, why not
> > use those? Might need some work to push basic userptr to them, but we have
> > enough drivers reinventing that wheel to justify that work.
> >
> > Can I guess also be done after merging.
>
> ... but if not, we can add this to TODO.

Yeah I'm fine with todo to cut these over to shmem helpers, this
driver has been stuck in limbo for way too long anyway.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch