On Wed, Nov 24, 2021 at 08:44:21PM +0800, Christian König wrote: > Keep track for which BO a resource was allocated. > This is necessary to move the LRU handling into the resources. > > A bit problematic is i915 since it tries to use the resource > interface without a BO which is illegal from the conceptional > point of view. > > v2: Document that this is a weak reference and add a workaround for i915 > v3: further document that this is protected by ttm_device::lru_lock and > clarify the i915 workaround > > Signed-off-by: Christian König <christian.koenig@xxxxxxx> > --- > drivers/gpu/drm/ttm/ttm_bo_util.c | 7 +++++-- > drivers/gpu/drm/ttm/ttm_resource.c | 9 +++++++++ > include/drm/ttm/ttm_resource.h | 4 ++++ > 3 files changed, 18 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c > index 95de2691ee7c..a2e3a9626198 100644 > --- a/drivers/gpu/drm/ttm/ttm_bo_util.c > +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c > @@ -237,6 +237,11 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo, > if (bo->type != ttm_bo_type_sg) > fbo->base.base.resv = &fbo->base.base._resv; > > + if (fbo->base.resource) { > + ttm_resource_set_bo(fbo->base.resource, &fbo->base); > + bo->resource = NULL; > + } > + > dma_resv_init(&fbo->base.base._resv); > fbo->base.base.dev = NULL; > ret = dma_resv_trylock(&fbo->base.base._resv); > @@ -512,7 +517,6 @@ static int ttm_bo_move_to_ghost(struct ttm_buffer_object *bo, > ghost_obj->ttm = NULL; > else > bo->ttm = NULL; > - bo->resource = NULL; > > dma_resv_unlock(&ghost_obj->base._resv); > ttm_bo_put(ghost_obj); > @@ -637,7 +641,6 @@ int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo) > dma_resv_unlock(&ghost->base._resv); > ttm_bo_put(ghost); > bo->ttm = ttm; > - bo->resource = NULL; > ttm_bo_assign_mem(bo, sys_res); > return 0; > > diff --git a/drivers/gpu/drm/ttm/ttm_resource.c b/drivers/gpu/drm/ttm/ttm_resource.c > index 41e7bf195168..7fdd58b53c61 100644 > --- a/drivers/gpu/drm/ttm/ttm_resource.c > +++ b/drivers/gpu/drm/ttm/ttm_resource.c > @@ -41,6 +41,7 @@ void ttm_resource_init(struct ttm_buffer_object *bo, > res->bus.offset = 0; > res->bus.is_iomem = false; > res->bus.caching = ttm_cached; > + res->bo = bo; > } > EXPORT_SYMBOL(ttm_resource_init); > > @@ -122,6 +123,14 @@ bool ttm_resource_compat(struct ttm_resource *res, > } > EXPORT_SYMBOL(ttm_resource_compat); > > +void ttm_resource_set_bo(struct ttm_resource *res, How about rename it as ttm_resource_set_bo_with_lru_locked? It's just a minor suggestion. Acked-by: Huang Rui <ray.huang@xxxxxxx> > + struct ttm_buffer_object *bo) > +{ > + spin_lock(&bo->bdev->lru_lock); > + res->bo = bo; > + spin_unlock(&bo->bdev->lru_lock); > +} > + > /** > * ttm_resource_manager_init > * > diff --git a/include/drm/ttm/ttm_resource.h b/include/drm/ttm/ttm_resource.h > index 6bf37383002b..69eea9d6399b 100644 > --- a/include/drm/ttm/ttm_resource.h > +++ b/include/drm/ttm/ttm_resource.h > @@ -161,6 +161,7 @@ struct ttm_bus_placement { > * @mem_type: Resource type of the allocation. > * @placement: Placement flags. > * @bus: Placement on io bus accessible to the CPU > + * @bo: weak reference to the BO, protected by ttm_device::lru_lock > * > * Structure indicating the placement and space resources used by a > * buffer object. > @@ -171,6 +172,7 @@ struct ttm_resource { > uint32_t mem_type; > uint32_t placement; > struct ttm_bus_placement bus; > + struct ttm_buffer_object *bo; > }; > > /** > @@ -271,6 +273,8 @@ int ttm_resource_alloc(struct ttm_buffer_object *bo, > void ttm_resource_free(struct ttm_buffer_object *bo, struct ttm_resource **res); > bool ttm_resource_compat(struct ttm_resource *res, > struct ttm_placement *placement); > +void ttm_resource_set_bo(struct ttm_resource *res, > + struct ttm_buffer_object *bo); > > void ttm_resource_manager_init(struct ttm_resource_manager *man, > struct ttm_device *bdev, > -- > 2.25.1 >