[PATCH v8] drm: Add library for shmem backed GEM objects

[Rob Herring]

On Wed, Mar 13, 2019 at 3:56 PM Eric Anholt <eric at anholt.net> wrote:
>
> Rob Herring <robh at kernel.org> writes:
>
> > From: Noralf Trønnes <noralf at tronnes.org>
> >
> > This adds a library for shmem backed GEM objects.
>
> I read through the whole thing, and the only bit I didn't like
> (drm_gem_shmem_create_with_handle returns an unrefcounted object
> pointer) was a copy-and-paste from CMA that we should fix in both
> places, and has no downside in the current usage since the pointer value
> is unused.  Just one question left:
>
> > v7:
> > - Use write-combine for mmap instead. This is the more common
> >   case. (robher)
>
> I don't actually see this in the code.  Wasn't there supposed to be a:
>
>        vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));

That's the default if you trace drm_gem_mmap() -> drm_gem_mmap_obj().
My wording here should have been more clear.

Rob