drm/nouveau: stop using TTMs fault callback

We already implemented the fault handler ourself,
just open code what is necessary here.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/392323/

drivers/gpu/drm/nouveau/nouveau_bo.c

@@ -1226,8 +1226,7 @@ nouveau_ttm_io_mem_free(struct ttm_bo_device *bdev, struct ttm_resource *reg)
 	mutex_unlock(&drm->ttm.io_reserve_mutex);
 }
 
-static int
-nouveau_ttm_fault_reserve_notify(struct ttm_buffer_object *bo)
+vm_fault_t nouveau_ttm_fault_reserve_notify(struct ttm_buffer_object *bo)
 {
 	struct nouveau_drm *drm = nouveau_bdev(bo->bdev);
 	struct nouveau_bo *nvbo = nouveau_bo(bo);
@@ -1243,34 +1242,38 @@ nouveau_ttm_fault_reserve_notify(struct ttm_buffer_object *bo)
 		    !nvbo->kind)
 			return 0;
 
-		if (bo->mem.mem_type == TTM_PL_SYSTEM) {
-			nouveau_bo_placement_set(nvbo, NOUVEAU_GEM_DOMAIN_GART,
-						 0);
+		if (bo->mem.mem_type != TTM_PL_SYSTEM)
+			return 0;
+
+		nouveau_bo_placement_set(nvbo, NOUVEAU_GEM_DOMAIN_GART, 0);
+
+	} else {
+		/* make sure bo is in mappable vram */
+		if (drm->client.device.info.family >= NV_DEVICE_INFO_V0_TESLA ||
+		    bo->mem.start + bo->mem.num_pages < mappable)
+			return 0;
 
-			ret = nouveau_bo_validate(nvbo, false, false);
-			if (ret)
-				return ret;
+		for (i = 0; i < nvbo->placement.num_placement; ++i) {
+			nvbo->placements[i].fpfn = 0;
+			nvbo->placements[i].lpfn = mappable;
 		}
-		return 0;
-	}
 
-	/* make sure bo is in mappable vram */
-	if (drm->client.device.info.family >= NV_DEVICE_INFO_V0_TESLA ||
-	    bo->mem.start + bo->mem.num_pages < mappable)
-		return 0;
+		for (i = 0; i < nvbo->placement.num_busy_placement; ++i) {
+			nvbo->busy_placements[i].fpfn = 0;
+			nvbo->busy_placements[i].lpfn = mappable;
+		}
 
-	for (i = 0; i < nvbo->placement.num_placement; ++i) {
-		nvbo->placements[i].fpfn = 0;
-		nvbo->placements[i].lpfn = mappable;
+		nouveau_bo_placement_set(nvbo, NOUVEAU_GEM_DOMAIN_VRAM, 0);
 	}
 
-	for (i = 0; i < nvbo->placement.num_busy_placement; ++i) {
-		nvbo->busy_placements[i].fpfn = 0;
-		nvbo->busy_placements[i].lpfn = mappable;
-	}
+	ret = nouveau_bo_validate(nvbo, false, false);
+	if (unlikely(ret == -EBUSY || ret == -ERESTARTSYS))
+		return VM_FAULT_NOPAGE;
+	else if (unlikely(ret))
+		return VM_FAULT_SIGBUS;
 
-	nouveau_bo_placement_set(nvbo, NOUVEAU_GEM_DOMAIN_VRAM, 0);
-	return nouveau_bo_validate(nvbo, false, false);
+	ttm_bo_move_to_lru_tail_unlocked(bo);
+	return 0;
 }
 
 static int
@@ -1381,7 +1384,6 @@ struct ttm_bo_driver nouveau_bo_driver = {
 	.move_notify = nouveau_bo_move_ntfy,
 	.move = nouveau_bo_move,
 	.verify_access = nouveau_bo_verify_access,
-	.fault_reserve_notify = &nouveau_ttm_fault_reserve_notify,
 	.io_mem_reserve = &nouveau_ttm_io_mem_reserve,
 	.io_mem_free = &nouveau_ttm_io_mem_free,
 };

drivers/gpu/drm/nouveau/nouveau_bo.h

@@ -89,6 +89,7 @@ void nouveau_bo_placement_set(struct nouveau_bo *, u32 type, u32 busy);
 void nouveau_bo_wr16(struct nouveau_bo *, unsigned index, u16 val);
 u32  nouveau_bo_rd32(struct nouveau_bo *, unsigned index);
 void nouveau_bo_wr32(struct nouveau_bo *, unsigned index, u32 val);
+vm_fault_t nouveau_ttm_fault_reserve_notify(struct ttm_buffer_object *bo);
 void nouveau_bo_fence(struct nouveau_bo *, struct nouveau_fence *, bool exclusive);
 int  nouveau_bo_validate(struct nouveau_bo *, bool interruptible,
 			 bool no_wait_gpu);

drivers/gpu/drm/nouveau/nouveau_ttm.c

@@ -134,17 +134,19 @@ static vm_fault_t nouveau_ttm_fault(struct vm_fault *vmf)
 	if (ret)
 		return ret;
 
-	nouveau_bo_del_io_reserve_lru(bo);
+	ret = nouveau_ttm_fault_reserve_notify(bo);
+	if (ret)
+		goto error_unlock;
 
+	nouveau_bo_del_io_reserve_lru(bo);
 	prot = vm_get_page_prot(vma->vm_flags);
 	ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT, 1);
+	nouveau_bo_add_io_reserve_lru(bo);
 	if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
 		return ret;
 
-	nouveau_bo_add_io_reserve_lru(bo);
-
+error_unlock:
 	dma_resv_unlock(bo->base.resv);
-
 	return ret;
 }