locking/barriers: Convert users of lockless_dereference() to READ_ONCE()

READ_ONCE() now has an implicit smp_read_barrier_depends() call, so it
can be used instead of lockless_dereference() without any change in
semantics.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1508840570-22169-4-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 1a9f70d44af9..a6ddc42f87a5 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -346,7 +346,7 @@ static inline void rcu_preempt_sleep_check(void) { }
 #define __rcu_dereference_check(p, c, space) \
 ({ \
         /* Dependency order vs. p above. */ \
-        typeof(*p) *________p1 = (typeof(*p) *__force)lockless_dereference(p); \
+        typeof(*p) *________p1 = (typeof(*p) *__force)READ_ONCE(p); \
         RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_check() usage"); \
         rcu_dereference_sparse(p, space); \
         ((typeof(*p) __force __kernel *)(________p1)); \
@@ -360,7 +360,7 @@ static inline void rcu_preempt_sleep_check(void) { }
 #define rcu_dereference_raw(p) \
 ({ \
         /* Dependency order vs. p above. */ \
-        typeof(p) ________p1 = lockless_dereference(p); \
+        typeof(p) ________p1 = READ_ONCE(p); \
         ((typeof(*p) __force __kernel *)(________p1)); \
 })