Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core locking updates from Ingo Molnar:
 "The main changes in this cycle are:

   - Another attempt at enabling cross-release lockdep dependency
     tracking (automatically part of CONFIG_PROVE_LOCKING=y), this time
     with better performance and fewer false positives. (Byungchul Park)

   - Introduce lockdep_assert_irqs_enabled()/disabled() and convert
     open-coded equivalents to lockdep variants. (Frederic Weisbecker)

   - Add down_read_killable() and use it in the VFS's iterate_dir()
     method. (Kirill Tkhai)

   - Convert remaining uses of ACCESS_ONCE() to
     READ_ONCE()/WRITE_ONCE(). Most of the conversion was Coccinelle
     driven. (Mark Rutland, Paul E. McKenney)

   - Get rid of lockless_dereference(), by strengthening Alpha atomics,
     strengthening READ_ONCE() with smp_read_barrier_depends() and thus
     being able to convert users of lockless_dereference() to
     READ_ONCE(). (Will Deacon)

   - Various micro-optimizations:

        - better PV qspinlocks (Waiman Long),
        - better x86 barriers (Michael S. Tsirkin)
        - better x86 refcounts (Kees Cook)

   - ... plus other fixes and enhancements. (Borislav Petkov, Juergen
     Gross, Miguel Bernal Marin)"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
  locking/x86: Use LOCK ADD for smp_mb() instead of MFENCE
  rcu: Use lockdep to assert IRQs are disabled/enabled
  netpoll: Use lockdep to assert IRQs are disabled/enabled
  timers/posix-cpu-timers: Use lockdep to assert IRQs are disabled/enabled
  sched/clock, sched/cputime: Use lockdep to assert IRQs are disabled/enabled
  irq_work: Use lockdep to assert IRQs are disabled/enabled
  irq/timings: Use lockdep to assert IRQs are disabled/enabled
  perf/core: Use lockdep to assert IRQs are disabled/enabled
  x86: Use lockdep to assert IRQs are disabled/enabled
  smp/core: Use lockdep to assert IRQs are disabled/enabled
  timers/hrtimer: Use lockdep to assert IRQs are disabled/enabled
  timers/nohz: Use lockdep to assert IRQs are disabled/enabled
  workqueue: Use lockdep to assert IRQs are disabled/enabled
  irq/softirqs: Use lockdep to assert IRQs are disabled/enabled
  locking/lockdep: Add IRQs disabled/enabled assertion APIs: lockdep_assert_irqs_enabled()/disabled()
  locking/pvqspinlock: Implement hybrid PV queued/unfair locks
  locking/rwlocks: Fix comments
  x86/paravirt: Set up the virt_spin_lock_key after static keys get initialized
  block, locking/lockdep: Assign a lock_class per gendisk used for wait_for_completion()
  workqueue: Remove now redundant lock acquisitions wrt. workqueue flushes
  ...

5 files changed, 8 insertions, 8 deletions

diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index af74d0433453..f9597ba26599 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -164,7 +164,7 @@ static void inet_frag_worker(struct work_struct *work)
 
 	local_bh_disable();
 
-	for (i = ACCESS_ONCE(f->next_bucket); budget; --budget) {
+	for (i = READ_ONCE(f->next_bucket); budget; --budget) {
 		evicted += inet_evict_bucket(f, &f->hash[i]);
 		i = (i + 1) & (INETFRAGS_HASHSZ - 1);
 		if (evicted > INETFRAGS_EVICT_MAX)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 3d9f1c2f81c5..c0864562083b 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -495,7 +495,7 @@ u32 ip_idents_reserve(u32 hash, int segs)
 {
 	u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ;
 	atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ;
-	u32 old = ACCESS_ONCE(*p_tstamp);
+	u32 old = READ_ONCE(*p_tstamp);
 	u32 now = (u32)jiffies;
 	u32 new, delta = 0;
 
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index b6bb3cdfad09..887585045b27 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -816,12 +816,12 @@ static void tcp_update_pacing_rate(struct sock *sk)
 	if (likely(tp->srtt_us))
 		do_div(rate, tp->srtt_us);
 
-	/* ACCESS_ONCE() is needed because sch_fq fetches sk_pacing_rate
+	/* WRITE_ONCE() is needed because sch_fq fetches sk_pacing_rate
 	 * without any lock. We want to make sure compiler wont store
 	 * intermediate values in this location.
 	 */
-	ACCESS_ONCE(sk->sk_pacing_rate) = min_t(u64, rate,
-						sk->sk_max_pacing_rate);
+	WRITE_ONCE(sk->sk_pacing_rate, min_t(u64, rate,
+					     sk->sk_max_pacing_rate));
 }
 
 /* Calculate rto without backoff.  This is the second half of Van Jacobson's
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 478909f4694d..5a42e873d44a 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1910,7 +1910,7 @@ static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb,
 	if ((skb != tcp_write_queue_tail(sk)) && (limit >= skb->len))
 		goto send_now;
 
-	win_divisor = ACCESS_ONCE(sysctl_tcp_tso_win_divisor);
+	win_divisor = READ_ONCE(sysctl_tcp_tso_win_divisor);
 	if (win_divisor) {
 		u32 chunk = min(tp->snd_wnd, tp->snd_cwnd * tp->mss_cache);
 
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index ebfbccae62fd..02ec9a349303 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1853,7 +1853,7 @@ static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 		 */
 
 		/* if we're overly short, let UDP handle it */
-		encap_rcv = ACCESS_ONCE(up->encap_rcv);
+		encap_rcv = READ_ONCE(up->encap_rcv);
 		if (encap_rcv) {
 			int ret;
 
@@ -2298,7 +2298,7 @@ void udp_destroy_sock(struct sock *sk)
 	unlock_sock_fast(sk, slow);
 	if (static_key_false(&udp_encap_needed) && up->encap_type) {
 		void (*encap_destroy)(struct sock *sk);
-		encap_destroy = ACCESS_ONCE(up->encap_destroy);
+		encap_destroy = READ_ONCE(up->encap_destroy);
 		if (encap_destroy)
 			encap_destroy(sk);
 	}