#ifndef __LINUX_RCUPDATE_H
#define __LINUX_RCUPDATE_H
-#ifdef __KERNEL__
-
#include <linux/cache.h>
#include <linux/spinlock.h>
#include <linux/threads.h>
#include <linux/cpumask.h>
#include <linux/seqlock.h>
#include <linux/lockdep.h>
+#include <linux/completion.h>
/**
* struct rcu_head - callback structure for use with RCU
*/
#define rcu_read_unlock_bh() __rcu_read_unlock_bh()
-/*
- * Prevent the compiler from merging or refetching accesses. The compiler
- * is also forbidden from reordering successive instances of ACCESS_ONCE(),
- * but only when the compiler is aware of some particular ordering. One way
- * to make the compiler aware of ordering is to put the two invocations of
- * ACCESS_ONCE() in different C statements.
- *
- * This macro does absolutely -nothing- to prevent the CPU from reordering,
- * merging, or refetching absolutely anything at any time.
- */
-#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
-
/**
* rcu_dereference - fetch an RCU-protected pointer in an
* RCU read-side critical section. This pointer may later
* code.
*/
-#define rcu_assign_pointer(p, v) ({ \
- smp_wmb(); \
- (p) = (v); \
- })
+#define rcu_assign_pointer(p, v) \
+ ({ \
+ if (!__builtin_constant_p(v) || \
+ ((v) != NULL)) \
+ smp_wmb(); \
+ (p) = (v); \
+ })
+
+/* Infrastructure to implement the synchronize_() primitives. */
+
+struct rcu_synchronize {
+ struct rcu_head head;
+ struct completion completion;
+};
+
+extern void wakeme_after_rcu(struct rcu_head *head);
+
+#define synchronize_rcu_xxx(name, func) \
+void name(void) \
+{ \
+ struct rcu_synchronize rcu; \
+ \
+ init_completion(&rcu.completion); \
+ /* Will wake me after RCU finished. */ \
+ func(&rcu.head, wakeme_after_rcu); \
+ /* Wait for it. */ \
+ wait_for_completion(&rcu.completion); \
+}
/**
* synchronize_sched - block until all CPUs have exited any non-preemptive
/* Exported common interfaces */
extern void synchronize_rcu(void);
extern void rcu_barrier(void);
-extern long rcu_batches_completed(void);
-extern long rcu_batches_completed_bh(void);
+extern void rcu_barrier_bh(void);
+extern void rcu_barrier_sched(void);
/* Internal to kernel */
extern void rcu_init(void);
extern int rcu_needs_cpu(int cpu);
-#endif /* __KERNEL__ */
#endif /* __LINUX_RCUPDATE_H */