some half-baked ttm ideas

[Christian König]

Hi Dave,

I think we should just completely nuke ttm_tt_bind() and ttm_tt_unbind() 
and all of that.

Drivers can to this from their move_notify() callback now instead.

Regards,
Christian.

Am 15.09.20 um 07:30 schrieb Dave Airlie:
> Hi Christian,
>
> I've been trying to move towards the idea of not having TTM manage the
> global TT, I'm still not sure what the result would look like so I've
> been randomly trying out a direction or two,
>
> There are some patches in :
> https://github.com/airlied/linux/commits/ttm-half-baked-ideas
>
> a) it splits use_tt into two flags, one for system memory backing and
> one for binding, and tries to use them correctly.
> b) adds cpu_pin/unpin hooks for the amdgpu/radeon drivers to use for userptr.
>
> I sort of envision being able to set the use_tt flag to false for
> drivers who don't want TTM to maintain their global TT, but I'm still
> not certain how that would look, I'd welcome any input there.
>
> Thanks,
> Dave.