drm/ttm: prevent moving of pinned BOs

We have checks for this in the individual drivers move callback, but
it's probably better to generally forbid that on a higher level.

Also stops exporting ttm_resource_compat() since that's not necessary
any more after removing the extra checks in vmwgfx.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230124125726.13323-4-christian.koenig@amd.com

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c

@@ -466,11 +466,7 @@ static int amdgpu_bo_move(struct ttm_buffer_object *bo, bool evict,
 			return r;
 	}
 
-	/* Can't move a pinned BO */
 	abo = ttm_to_amdgpu_bo(bo);
-	if (WARN_ON_ONCE(abo->tbo.pin_count > 0))
-		return -EINVAL;
-
 	adev = amdgpu_ttm_adev(bo->bdev);
 
 	if (!old_mem || (old_mem->mem_type == TTM_PL_SYSTEM &&

drivers/gpu/drm/nouveau/nouveau_bo.c

@@ -1015,9 +1015,6 @@ nouveau_bo_move(struct ttm_buffer_object *bo, bool evict,
 	if (ret)
 		goto out_ntfy;
 
-	if (nvbo->bo.pin_count)
-		NV_WARN(drm, "Moving pinned object %p!\n", nvbo);
-
 	if (drm->client.device.info.family < NV_DEVICE_INFO_V0_TESLA) {
 		ret = nouveau_bo_vm_bind(bo, new_reg, &new_tile);
 		if (ret)

drivers/gpu/drm/radeon/radeon_ttm.c

@@ -211,11 +211,7 @@ static int radeon_bo_move(struct ttm_buffer_object *bo, bool evict,
 	if (r)
 		return r;
 
-	/* Can't move a pinned BO */
 	rbo = container_of(bo, struct radeon_bo, tbo);
-	if (WARN_ON_ONCE(rbo->tbo.pin_count > 0))
-		return -EINVAL;
-
 	rdev = radeon_get_rdev(bo->bdev);
 	if (old_mem->mem_type == TTM_PL_SYSTEM && bo->ttm == NULL) {
 		ttm_bo_move_null(bo, new_mem);

drivers/gpu/drm/ttm/ttm_bo.c

@@ -894,14 +894,18 @@ int ttm_bo_validate(struct ttm_buffer_object *bo,
 	if (!placement->num_placement && !placement->num_busy_placement)
 		return ttm_bo_pipeline_gutting(bo);
 
-	/*
-	 * Check whether we need to move buffer.
-	 */
-	if (!bo->resource || !ttm_resource_compat(bo->resource, placement)) {
-		ret = ttm_bo_move_buffer(bo, placement, ctx);
-		if (ret)
-			return ret;
-	}
+	/* Check whether we need to move buffer. */
+	if (bo->resource && ttm_resource_compat(bo->resource, placement))
+		return 0;
+
+	/* Moving of pinned BOs is forbidden */
+	if (bo->pin_count)
+		return -EINVAL;
+
+	ret = ttm_bo_move_buffer(bo, placement, ctx);
+	if (ret)
+		return ret;
+
 	/*
 	 * We might need to add a TTM.
 	 */

drivers/gpu/drm/ttm/ttm_resource.c

@@ -361,7 +361,6 @@ bool ttm_resource_compat(struct ttm_resource *res,
 
 	return false;
 }
-EXPORT_SYMBOL(ttm_resource_compat);
 
 void ttm_resource_set_bo(struct ttm_resource *res,
 			 struct ttm_buffer_object *bo)

drivers/gpu/drm/vmwgfx/vmwgfx_bo.c

@@ -87,12 +87,7 @@ int vmw_bo_pin_in_placement(struct vmw_private *dev_priv,
 	if (unlikely(ret != 0))
 		goto err;
 
-	if (buf->base.pin_count > 0)
-		ret = ttm_resource_compat(bo->resource, placement)
-			? 0 : -EINVAL;
-	else
-		ret = ttm_bo_validate(bo, placement, &ctx);
-
+	ret = ttm_bo_validate(bo, placement, &ctx);
 	if (!ret)
 		vmw_bo_pin_reserved(buf, true);
 
@@ -128,12 +123,6 @@ int vmw_bo_pin_in_vram_or_gmr(struct vmw_private *dev_priv,
 	if (unlikely(ret != 0))
 		goto err;
 
-	if (buf->base.pin_count > 0) {
-		ret = ttm_resource_compat(bo->resource, &vmw_vram_gmr_placement)
-			? 0 : -EINVAL;
-		goto out_unreserve;
-	}
-
 	ret = ttm_bo_validate(bo, &vmw_vram_gmr_placement, &ctx);
 	if (likely(ret == 0) || ret == -ERESTARTSYS)
 		goto out_unreserve;
@@ -218,11 +207,7 @@ int vmw_bo_pin_in_start_of_vram(struct vmw_private *dev_priv,
 		(void) ttm_bo_validate(bo, &vmw_sys_placement, &ctx);
 	}
 
-	if (buf->base.pin_count > 0)
-		ret = ttm_resource_compat(bo->resource, &placement)
-			? 0 : -EINVAL;
-	else
-		ret = ttm_bo_validate(bo, &placement, &ctx);
+	ret = ttm_bo_validate(bo, &placement, &ctx);
 
 	/* For some reason we didn't end up at the start of vram */
 	WARN_ON(ret == 0 && bo->resource->start != 0);