Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild...

[linux-2.6-omap-h63xx.git] / include / linux / rcupdate.h

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 37a642c54871f24166bec8e9b23b73e3369848bb..86f1f5e43e333766ec6a9fe5276875046c2f2526 100644 (file)
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -33,8 +33,6 @@
 #ifndef __LINUX_RCUPDATE_H
 #define __LINUX_RCUPDATE_H
 
-#ifdef __KERNEL__
-
 #include <linux/cache.h>
 #include <linux/spinlock.h>
 #include <linux/threads.h>
@@ -42,6 +40,7 @@
 #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
@@ -133,17 +132,25 @@ struct rcu_head {
  */
 #define rcu_read_unlock_bh() __rcu_read_unlock_bh()
 
+/**
+ * rcu_read_lock_sched - mark the beginning of a RCU-classic critical section
+ *
+ * Should be used with either
+ * - synchronize_sched()
+ * or
+ * - call_rcu_sched() and rcu_barrier_sched()
+ * on the write-side to insure proper synchronization.
+ */
+#define rcu_read_lock_sched() preempt_disable()
+
 /*
- * 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.
+ * rcu_read_unlock_sched - marks the end of a RCU-classic critical section
+ *
+ * See rcu_read_lock_sched for more information.
  */
-#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
+#define rcu_read_unlock_sched() preempt_enable()
+
+
 
 /**
  * rcu_dereference - fetch an RCU-protected pointer in an
@@ -182,6 +189,27 @@ struct rcu_head {
                (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
  * kernel code sequences.
@@ -238,12 +266,11 @@ extern void call_rcu_bh(struct rcu_head *head,
 /* 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 */