[Intel-gfx] [PATCH 0/1] drm: Add a gpu page-table walker

[Daniel Vetter]

On Thu, Feb 16, 2023 at 05:27:28PM +0100, Thomas Hellström wrote:
> A slightly unusual cover letter for a single patch.
> 
> The page table walker is currently used by the xe driver only,
> but the code is generic so we can be good citizens and add it to drm
> as a helper, for possible use by other drivers,
> If so we can merge the commit when we merge the xe driver.
> 
> The question raised here is
> *) Should it be a generic drm helper or xe-specific with changed
>    prefixes?

I think if there's some other drivers interested in using this, then this
sounds like a good idea. Maybe more useful if it's also integrated into
the vm/vma helpers that are being discussed as an optional part?

Maybe some good old sales pitching here to convince people would be good.

Maybe one of the new accel drivers is interested in this too?

> *) If a drm helper, should we use a config option?

I am no fan of Kconfig things tbh. Maybe just include it in the vma
helpers, or perhaps we want to do a drm-accel-helpers with gem helpers,
drm/sched, this one here, vm/vma helpers or whatever they will be and so
on? Kinda like we have modeset helpers.

I'd definitely not go for a Kconfig per individual file, that's just
excessive.
-Daniel

> 
> For usage examples, see xe_pt.c
> https://gitlab.freedesktop.org/drm/xe/kernel/-/blob/drm-xe-next/drivers/gpu/drm/xe/xe_pt.c
> 
> Thanks,
> Thomas
> 
> Thomas Hellström (1):
>   drm: Add a gpu page-table walker helper
> 
>  drivers/gpu/drm/Makefile      |   1 +
>  drivers/gpu/drm/drm_pt_walk.c | 159 +++++++++++++++++++++++++++++++++
>  include/drm/drm_pt_walk.h     | 161 ++++++++++++++++++++++++++++++++++
>  3 files changed, 321 insertions(+)
>  create mode 100644 drivers/gpu/drm/drm_pt_walk.c
>  create mode 100644 include/drm/drm_pt_walk.h
> 
> -- 
> 2.34.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch