drm/nouveau/vm: reduce number of entry-points to vm_map()

Pretty much everywhere had to make the decision which to use, so it
makes a lot more sense to just have one entrypoint decide the path
to take instead.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_sgdma.c

@@ -31,16 +31,17 @@ nv04_sgdma_bind(struct ttm_tt *ttm, struct ttm_mem_reg *mem)
 {
 	struct nouveau_sgdma_be *nvbe = (struct nouveau_sgdma_be *)ttm;
 	struct nouveau_mem *node = mem->mm_node;
-	u64 size = mem->num_pages << 12;
 
 	if (ttm->sg) {
-		node->sg = ttm->sg;
-		nouveau_vm_map_sg_table(&node->vma[0], 0, size, node);
+		node->sg    = ttm->sg;
+		node->pages = NULL;
 	} else {
+		node->sg    = NULL;
 		node->pages = nvbe->ttm.dma_address;
-		nouveau_vm_map_sg(&node->vma[0], 0, size, node);
 	}
+	node->size = (mem->num_pages << PAGE_SHIFT) >> 12;
 
+	nouveau_vm_map(&node->vma[0], node);
 	nvbe->node = node;
 	return 0;
 }
@@ -67,9 +68,13 @@ nv50_sgdma_bind(struct ttm_tt *ttm, struct ttm_mem_reg *mem)
 
 	/* noop: bound in move_notify() */
 	if (ttm->sg) {
-		node->sg = ttm->sg;
-	} else
+		node->sg    = ttm->sg;
+		node->pages = NULL;
+	} else {
+		node->sg    = NULL;
 		node->pages = nvbe->ttm.dma_address;
+	}
+	node->size = (mem->num_pages << PAGE_SHIFT) >> 12;
 	return 0;
 }