[PATCH] thunderbolt: tunnel: simplify allocation

[PATCH] thunderbolt: tunnel: simplify allocation

[Rosen Penev]

Use a flexible array member and kzalloc_flex to combine allocations.

Add __counted_by for extra runtime analysis. Move counting variable
assignment after allocation as required by __counted_by.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/thunderbolt/tunnel.c | 10 ++--------
 drivers/thunderbolt/tunnel.h |  3 ++-
 2 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c
index 89676acf1290..f38f7753b6e4 100644
--- a/drivers/thunderbolt/tunnel.c
+++ b/drivers/thunderbolt/tunnel.c
@@ -180,19 +180,14 @@ static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths,
 {
 	struct tb_tunnel *tunnel;
 
-	tunnel = kzalloc_obj(*tunnel);
+	tunnel = kzalloc_flex(*tunnel, paths, npaths);
 	if (!tunnel)
 		return NULL;
 
-	tunnel->paths = kzalloc_objs(tunnel->paths[0], npaths);
-	if (!tunnel->paths) {
-		kfree(tunnel);
-		return NULL;
-	}
+	tunnel->npaths = npaths;
 
 	INIT_LIST_HEAD(&tunnel->list);
 	tunnel->tb = tb;
-	tunnel->npaths = npaths;
 	tunnel->type = type;
 	kref_init(&tunnel->kref);
 
@@ -219,7 +214,6 @@ static void tb_tunnel_destroy(struct kref *kref)
 			tb_path_free(tunnel->paths[i]);
 	}
 
-	kfree(tunnel->paths);
 	kfree(tunnel);
 }
 
diff --git a/drivers/thunderbolt/tunnel.h b/drivers/thunderbolt/tunnel.h
index 2c44fc8a10bc..55eb83900a2f 100644
--- a/drivers/thunderbolt/tunnel.h
+++ b/drivers/thunderbolt/tunnel.h
@@ -75,7 +75,6 @@ struct tb_tunnel {
 	struct tb *tb;
 	struct tb_port *src_port;
 	struct tb_port *dst_port;
-	struct tb_path **paths;
 	size_t npaths;
 	int (*pre_activate)(struct tb_tunnel *tunnel);
 	int (*activate)(struct tb_tunnel *tunnel, bool activate);
@@ -107,6 +106,8 @@ struct tb_tunnel {
 	struct delayed_work dprx_work;
 	void (*callback)(struct tb_tunnel *tunnel, void *data);
 	void *callback_data;
+
+	struct tb_path *paths[] __counted_by(npaths);
 };
 
 struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down,
-- 
2.53.0

Re: [PATCH] thunderbolt: tunnel: simplify allocation

[Mika Westerberg]

On Mon, Mar 30, 2026 at 02:10:14PM -0700, Rosen Penev wrote:
> +++ b/drivers/thunderbolt/tunnel.h
> @@ -75,7 +75,6 @@ struct tb_tunnel {
>  	struct tb *tb;
>  	struct tb_port *src_port;
>  	struct tb_port *dst_port;
> -	struct tb_path **paths;
>  	size_t npaths;
>  	int (*pre_activate)(struct tb_tunnel *tunnel);
>  	int (*activate)(struct tb_tunnel *tunnel, bool activate);
> @@ -107,6 +106,8 @@ struct tb_tunnel {
>  	struct delayed_work dprx_work;
>  	void (*callback)(struct tb_tunnel *tunnel, void *data);
>  	void *callback_data;
> +
> +	struct tb_path *paths[] __counted_by(npaths);

Please move the kernel-doc to the right place as well.