[PATCH] drm/ttm: use the parent resv for ghost objects v2

[Christian König]

This way the TTM is destroyed with the correct dma_resv object
locked and we can even pipeline imported BO evictions.

v2: Limit this to only cases when the parent object uses a separate
    reservation object as well. This fixes another OOM problem.

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 drivers/gpu/drm/ttm/ttm_bo_util.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index e030c27f53cf..45e440f80b7b 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -512,7 +512,9 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
 	kref_init(&fbo->base.kref);
 	fbo->base.destroy = &ttm_transfered_destroy;
 	fbo->base.acc_size = 0;
-	fbo->base.base.resv = &fbo->base.base._resv;
+	if (bo->base.resv == &bo->base._resv)
+		fbo->base.base.resv = &fbo->base.base._resv;
+
 	dma_resv_init(fbo->base.base.resv);
 	ret = dma_resv_trylock(fbo->base.base.resv);
 	WARN_ON(!ret);
@@ -711,7 +713,7 @@ int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
 		if (ret)
 			return ret;
 
-		dma_resv_add_excl_fence(ghost_obj->base.resv, fence);
+		dma_resv_add_excl_fence(&ghost_obj->base._resv, fence);
 
 		/**
 		 * If we're not moving to fixed memory, the TTM object
@@ -724,7 +726,7 @@ int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
 		else
 			bo->ttm = NULL;
 
-		ttm_bo_unreserve(ghost_obj);
+		dma_resv_unlock(&ghost_obj->base._resv);
 		ttm_bo_put(ghost_obj);
 	}
 
@@ -767,7 +769,7 @@ int ttm_bo_pipeline_move(struct ttm_buffer_object *bo,
 		if (ret)
 			return ret;
 
-		dma_resv_add_excl_fence(ghost_obj->base.resv, fence);
+		dma_resv_add_excl_fence(&ghost_obj->base._resv, fence);
 
 		/**
 		 * If we're not moving to fixed memory, the TTM object
@@ -780,7 +782,7 @@ int ttm_bo_pipeline_move(struct ttm_buffer_object *bo,
 		else
 			bo->ttm = NULL;
 
-		ttm_bo_unreserve(ghost_obj);
+		dma_resv_unlock(&ghost_obj->base._resv);
 		ttm_bo_put(ghost_obj);
 
 	} else if (from->flags & TTM_MEMTYPE_FLAG_FIXED) {
@@ -836,7 +838,7 @@ int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo)
 	if (ret)
 		return ret;
 
-	ret = dma_resv_copy_fences(ghost->base.resv, bo->base.resv);
+	ret = dma_resv_copy_fences(&ghost->base._resv, bo->base.resv);
 	/* Last resort, wait for the BO to be idle when we are OOM */
 	if (ret)
 		ttm_bo_wait(bo, false, false);
@@ -845,7 +847,7 @@ int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo)
 	bo->mem.mem_type = TTM_PL_SYSTEM;
 	bo->ttm = NULL;
 
-	ttm_bo_unreserve(ghost);
+	dma_resv_unlock(&ghost->base._resv);
 	ttm_bo_put(ghost);
 
 	return 0;
-- 
2.17.1