net/udp: Update udp_encap_needed static key to modern api

No changes in refcount semantics -- key init is false; replace

static_key_enable         with   static_branch_enable
static_key_slow_inc|dec   with   static_branch_inc|dec
static_key_false          with   static_branch_unlikely

Added a '_key' suffix to udp and udpv6 encap_needed, for better
self documentation.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/udp.c

@@ -1875,10 +1875,10 @@ static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 	return 0;
 }
 
-static struct static_key udp_encap_needed __read_mostly;
+static DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key);
 void udp_encap_enable(void)
 {
-	static_key_enable(&udp_encap_needed);
+	static_branch_enable(&udp_encap_needed_key);
 }
 EXPORT_SYMBOL(udp_encap_enable);
 
@@ -1902,7 +1902,7 @@ static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 		goto drop;
 	nf_reset(skb);
 
-	if (static_key_false(&udp_encap_needed) && up->encap_type) {
+	if (static_branch_unlikely(&udp_encap_needed_key) && up->encap_type) {
 		int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
 
 		/*
@@ -2365,7 +2365,7 @@ void udp_destroy_sock(struct sock *sk)
 	bool slow = lock_sock_fast(sk);
 	udp_flush_pending_frames(sk);
 	unlock_sock_fast(sk, slow);
-	if (static_key_false(&udp_encap_needed) && up->encap_type) {
+	if (static_branch_unlikely(&udp_encap_needed_key) && up->encap_type) {
 		void (*encap_destroy)(struct sock *sk);
 		encap_destroy = READ_ONCE(up->encap_destroy);
 		if (encap_destroy)

net/ipv6/udp.c

@@ -546,10 +546,10 @@ static __inline__ void udpv6_err(struct sk_buff *skb,
 	__udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
 }
 
-static struct static_key udpv6_encap_needed __read_mostly;
+static DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
 void udpv6_encap_enable(void)
 {
-	static_key_enable(&udpv6_encap_needed);
+	static_branch_enable(&udpv6_encap_needed_key);
 }
 EXPORT_SYMBOL(udpv6_encap_enable);
 
@@ -561,7 +561,7 @@ static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
 		goto drop;
 
-	if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
+	if (static_branch_unlikely(&udpv6_encap_needed_key) && up->encap_type) {
 		int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
 
 		/*
@@ -1427,7 +1427,7 @@ void udpv6_destroy_sock(struct sock *sk)
 	udp_v6_flush_pending_frames(sk);
 	release_sock(sk);
 
-	if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
+	if (static_branch_unlikely(&udpv6_encap_needed_key) && up->encap_type) {
 		void (*encap_destroy)(struct sock *sk);
 		encap_destroy = READ_ONCE(up->encap_destroy);
 		if (encap_destroy)