On Wed, 20 Jan 2021 at 15:40, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > > If we import a shmemfs object between devices, for example from > Tigerlake to DG1, we can simply reuse the native object and its backing > store. Hmmm interesting, so does that include re-using the actual sg mapping for the backing pages? Does that work out-of-the-box between different devices assuming we have iommu enabled? > > Suggested-by: Imre Deak <imre.deak@xxxxxxxxx> > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Cc: Matthew Auld <matthew.auld@xxxxxxxxx> > Cc: Imre Deak <imre.deak@xxxxxxxxx> > --- > drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c > index 04e9c04545ad..4816f08c4009 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c > @@ -242,6 +242,13 @@ struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev, > */ > return &i915_gem_object_get(obj)->base; > } > + > + /* > + * If the object is in plain system memory, we can reuse the > + * same backing store in any device. > + */ > + if (i915_gem_object_is_shmem(obj)) > + return &i915_gem_object_get(obj)->base; > } > > /* need to attach */ > -- > 2.20.1 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/intel-gfx _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
