Bluetooth: Add stop LE auto connection feature

[platform/kernel/linux-starfive.git] / net / ipv4 / tcp_cong.c

diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
index db8b4b4..1b34050 100644 (file)
--- a/net/ipv4/tcp_cong.c
+++ b/net/ipv4/tcp_cong.c
@@ -75,14 +75,8 @@ struct tcp_congestion_ops *tcp_ca_find_key(u32 key)
        return NULL;
 }
 
-/*
- * Attach new congestion control algorithm to the list
- * of available options.
- */
-int tcp_register_congestion_control(struct tcp_congestion_ops *ca)
+int tcp_validate_congestion_control(struct tcp_congestion_ops *ca)
 {
-       int ret = 0;
-
        /* all algorithms must implement these */
        if (!ca->ssthresh || !ca->undo_cwnd ||
            !(ca->cong_avoid || ca->cong_control)) {
@@ -90,6 +84,20 @@ int tcp_register_congestion_control(struct tcp_congestion_ops *ca)
                return -EINVAL;
        }
 
+       return 0;
+}
+
+/* Attach new congestion control algorithm to the list
+ * of available options.
+ */
+int tcp_register_congestion_control(struct tcp_congestion_ops *ca)
+{
+       int ret;
+
+       ret = tcp_validate_congestion_control(ca);
+       if (ret)
+               return ret;
+
        ca->key = jhash(ca->name, sizeof(ca->name), strlen(ca->name));
 
        spin_lock(&tcp_cong_list_lock);
@@ -130,6 +138,50 @@ void tcp_unregister_congestion_control(struct tcp_congestion_ops *ca)
 }
 EXPORT_SYMBOL_GPL(tcp_unregister_congestion_control);
 
+/* Replace a registered old ca with a new one.
+ *
+ * The new ca must have the same name as the old one, that has been
+ * registered.
+ */
+int tcp_update_congestion_control(struct tcp_congestion_ops *ca, struct tcp_congestion_ops *old_ca)
+{
+       struct tcp_congestion_ops *existing;
+       int ret;
+
+       ret = tcp_validate_congestion_control(ca);
+       if (ret)
+               return ret;
+
+       ca->key = jhash(ca->name, sizeof(ca->name), strlen(ca->name));
+
+       spin_lock(&tcp_cong_list_lock);
+       existing = tcp_ca_find_key(old_ca->key);
+       if (ca->key == TCP_CA_UNSPEC || !existing || strcmp(existing->name, ca->name)) {
+               pr_notice("%s not registered or non-unique key\n",
+                         ca->name);
+               ret = -EINVAL;
+       } else if (existing != old_ca) {
+               pr_notice("invalid old congestion control algorithm to replace\n");
+               ret = -EINVAL;
+       } else {
+               /* Add the new one before removing the old one to keep
+                * one implementation available all the time.
+                */
+               list_add_tail_rcu(&ca->list, &tcp_cong_list);
+               list_del_rcu(&existing->list);
+               pr_debug("%s updated\n", ca->name);
+       }
+       spin_unlock(&tcp_cong_list_lock);
+
+       /* Wait for outstanding readers to complete before the
+        * module or struct_ops gets removed entirely.
+        */
+       if (!ret)
+               synchronize_rcu();
+
+       return ret;
+}
+
 u32 tcp_ca_get_key_by_name(struct net *net, const char *name, bool *ecn_ca)
 {
        const struct tcp_congestion_ops *ca;