[PATCH v2 tip/core/rcu 2/9] Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE() in rcupdate.h

Paul E. McKenney
2015-03-16T18:42:38Z

This commit moves include/linux/rcupdate.h from the old ACCESS_ONCE()
API to the new READ_ONCE() and WRITE_ONCE() APIs.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
include/linux/rcupdate.h | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 573a5afd5ed8..87bb0eee665b 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -364,8 +364,8 @@ extern struct srcu_struct tasks_rcu_exit_srcu;
#define rcu_note_voluntary_context_switch(t) \
do { \
rcu_all_qs(); \
- if (ACCESS_ONCE((t)->rcu_tasks_holdout)) \
- ACCESS_ONCE((t)->rcu_tasks_holdout) = false; \
+ if (READ_ONCE((t)->rcu_tasks_holdout)) \
+ WRITE_ONCE((t)->rcu_tasks_holdout, false); \
} while (0)
#else /* #ifdef CONFIG_TASKS_RCU */
#define TASKS_RCU(x) do { } while (0)
@@ -609,7 +609,7 @@ static inline void rcu_preempt_sleep_check(void)

#define __rcu_access_pointer(p, space) \
({ \
- typeof(*p) *_________p1 = (typeof(*p) *__force)ACCESS_ONCE(p); \
+ typeof(*p) *_________p1 = (typeof(*p) *__force)READ_ONCE(p); \
rcu_dereference_sparse(p, space); \
((typeof(*p) __force __kernel *)(_________p1)); \
})
@@ -630,7 +630,7 @@ static inline void rcu_preempt_sleep_check(void)

#define __rcu_access_index(p, space) \
({ \
- typeof(p) _________p1 = ACCESS_ONCE(p); \
+ typeof(p) _________p1 = READ_ONCE(p); \
rcu_dereference_sparse(p, space); \
(_________p1); \
})
@@ -659,7 +659,7 @@ static inline void rcu_preempt_sleep_check(void)
*/
#define lockless_dereference(p) \
({ \
- typeof(p) _________p1 = ACCESS_ONCE(p); \
+ typeof(p) _________p1 = READ_ONCE(p); \
smp_read_barrier_depends(); /* Dependency order vs. p above. */ \
(_________p1); \
})
@@ -702,7 +702,7 @@ static inline void rcu_preempt_sleep_check(void)
* @p: The pointer to read
*
* Return the value of the specified RCU-protected pointer, but omit the
- * smp_read_barrier_depends() and keep the ACCESS_ONCE(). This is useful
+ * smp_read_barrier_depends() and keep the READ_ONCE(). This is useful
* when the value of this pointer is accessed, but the pointer is not
* dereferenced, for example, when testing an RCU-protected pointer against
* NULL. Although rcu_access_pointer() may also be used in cases where
@@ -791,7 +791,7 @@ static inline void rcu_preempt_sleep_check(void)
* @p: The index to read
*
* Return the value of the specified RCU-protected index, but omit the
- * smp_read_barrier_depends() and keep the ACCESS_ONCE(). This is useful
+ * smp_read_barrier_depends() and keep the READ_ONCE(). This is useful
* when the value of this index is accessed, but the index is not
* dereferenced, for example, when testing an RCU-protected index against
* -1. Although rcu_access_index() may also be used in cases where
@@ -827,7 +827,7 @@ static inline void rcu_preempt_sleep_check(void)
* @c: The conditions under which the dereference will take place
*
* Return the value of the specified RCU-protected pointer, but omit
- * both the smp_read_barrier_depends() and the ACCESS_ONCE(). This
+ * both the smp_read_barrier_depends() and the READ_ONCE(). This
* is useful in cases where update-side locks prevent the value of the
* pointer from changing. Please note that this primitive does -not-
* prevent the compiler from repeating this reference or combining it
--
1.8.1.5