[PATCH] thunderbolt: use kzalloc_flex

[Rosen Penev]

Simplifies allocation by using a flexible arraay member.

Added __counted_by for extra runtime analysis.

Signed-off-by: Rosen Penev <ros...@gmail.com>
---
 drivers/thunderbolt/path.c | 24 ++++++------------------
 drivers/thunderbolt/tb.h   |  3 ++-
 2 files changed, 8 insertions(+), 19 deletions(-)

diff --git a/drivers/thunderbolt/path.c b/drivers/thunderbolt/path.c
index 22fb4a1e1acd..3af5d263ac74 100644
--- a/drivers/thunderbolt/path.c
+++ b/drivers/thunderbolt/path.c
@@ -150,22 +150,17 @@ struct tb_path *tb_path_discover(struct tb_port *src, int 
src_hopid,
                num_hops++;
        }
 
-       path = kzalloc_obj(*path);
+       path = kzalloc_flex(*path, hops, num_hops);
        if (!path)
                return NULL;
 
+       path->path_length = num_hops;
+
        path->name = name;
        path->tb = src->sw->tb;
-       path->path_length = num_hops;
        path->activated = true;
        path->alloc_hopid = alloc_hopid;
 
-       path->hops = kzalloc_objs(*path->hops, num_hops);
-       if (!path->hops) {
-               kfree(path);
-               return NULL;
-       }
-
        tb_dbg(path->tb, "discovering %s path starting from %llx:%u\n",
               path->name, tb_route(src->sw), src->port);
 
@@ -245,10 +240,6 @@ struct tb_path *tb_path_alloc(struct tb *tb, struct 
tb_port *src, int src_hopid,
        size_t num_hops;
        int i, ret;
 
-       path = kzalloc_obj(*path);
-       if (!path)
-               return NULL;
-
        first_port = last_port = NULL;
        i = 0;
        tb_for_each_port_on_path(src, dst, in_port) {
@@ -267,12 +258,11 @@ struct tb_path *tb_path_alloc(struct tb *tb, struct 
tb_port *src, int src_hopid,
        /* Each hop takes two ports */
        num_hops = i / 2;
 
-       path->hops = kzalloc_objs(*path->hops, num_hops);
-       if (!path->hops) {
-               kfree(path);
+       path = kzalloc_flex(*path, hops, num_hops);
+       if (!path)
                return NULL;
-       }
 
+       path->path_length = num_hops;
        path->alloc_hopid = true;
 
        in_hopid = src_hopid;
@@ -339,7 +329,6 @@ struct tb_path *tb_path_alloc(struct tb *tb, struct tb_port 
*src, int src_hopid,
        }
 
        path->tb = tb;
-       path->path_length = num_hops;
        path->name = name;
 
        return path;
@@ -372,7 +361,6 @@ void tb_path_free(struct tb_path *path)
                }
        }
 
-       kfree(path->hops);
        kfree(path);
 }
 
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index e96474f17067..4e66b53860dd 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -440,9 +440,10 @@ struct tb_path {
        bool drop_packages;
        bool activated;
        bool clear_fc;
-       struct tb_path_hop *hops;
        int path_length;
        bool alloc_hopid;
+
+       struct tb_path_hop hops[] __counted_by(path_length);
 };
 
 /* HopIDs 0-7 are reserved by the Thunderbolt protocol */
-- 
2.53.0