drm/xe/bo: Fix swapin when moving to VRAM

When a source system resource had been swapped out, we incorrectly
assumed that we were lacking source data for a move and therefore
cleared the destination instead of swapping in and copying the
swapped-out data. Fix this.
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230626181741.32820-2-thomas.hellstrom@linux.intel.comSigned-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/xe/xe_bo.c

@@ -568,6 +568,7 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict,
 	struct xe_tile *tile = NULL;
 	struct dma_fence *fence;
 	bool move_lacks_source;
+	bool tt_has_data;
 	bool needs_clear;
 	int ret = 0;
 
@@ -590,8 +591,10 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict,
 		goto out;
 	}
 
-	move_lacks_source = !resource_is_vram(old_mem) &&
-		(!ttm || !ttm_tt_is_populated(ttm));
+	tt_has_data = ttm && (ttm_tt_is_populated(ttm) ||
+			      (ttm->page_flags & TTM_TT_FLAG_SWAPPED));
+
+	move_lacks_source = !resource_is_vram(old_mem) && !tt_has_data;
 
 	needs_clear = (ttm && ttm->page_flags & TTM_TT_FLAG_ZERO_ALLOC) ||
 		(!ttm && ttm_bo->type == ttm_bo_type_device);