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-rw-r--r--include/linux/rwsem.h96
1 files changed, 38 insertions, 58 deletions
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index f99fe90732a..7b524b4109a 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -9,8 +9,6 @@
#include <linux/linkage.h>
-#define RWSEM_DEBUG 0
-
#ifdef __KERNEL__
#include <linux/types.h>
@@ -26,89 +24,71 @@ struct rw_semaphore;
#include <asm/rwsem.h> /* use an arch-specific implementation */
#endif
-#ifndef rwsemtrace
-#if RWSEM_DEBUG
-extern void FASTCALL(rwsemtrace(struct rw_semaphore *sem, const char *str));
-#else
-#define rwsemtrace(SEM,FMT)
-#endif
-#endif
-
/*
* lock for reading
*/
-static inline void down_read(struct rw_semaphore *sem)
-{
- might_sleep();
- rwsemtrace(sem,"Entering down_read");
- __down_read(sem);
- rwsemtrace(sem,"Leaving down_read");
-}
+extern void down_read(struct rw_semaphore *sem);
/*
* trylock for reading -- returns 1 if successful, 0 if contention
*/
-static inline int down_read_trylock(struct rw_semaphore *sem)
-{
- int ret;
- rwsemtrace(sem,"Entering down_read_trylock");
- ret = __down_read_trylock(sem);
- rwsemtrace(sem,"Leaving down_read_trylock");
- return ret;
-}
+extern int down_read_trylock(struct rw_semaphore *sem);
/*
* lock for writing
*/
-static inline void down_write(struct rw_semaphore *sem)
-{
- might_sleep();
- rwsemtrace(sem,"Entering down_write");
- __down_write(sem);
- rwsemtrace(sem,"Leaving down_write");
-}
+extern void down_write(struct rw_semaphore *sem);
/*
* trylock for writing -- returns 1 if successful, 0 if contention
*/
-static inline int down_write_trylock(struct rw_semaphore *sem)
-{
- int ret;
- rwsemtrace(sem,"Entering down_write_trylock");
- ret = __down_write_trylock(sem);
- rwsemtrace(sem,"Leaving down_write_trylock");
- return ret;
-}
+extern int down_write_trylock(struct rw_semaphore *sem);
/*
* release a read lock
*/
-static inline void up_read(struct rw_semaphore *sem)
-{
- rwsemtrace(sem,"Entering up_read");
- __up_read(sem);
- rwsemtrace(sem,"Leaving up_read");
-}
+extern void up_read(struct rw_semaphore *sem);
/*
* release a write lock
*/
-static inline void up_write(struct rw_semaphore *sem)
-{
- rwsemtrace(sem,"Entering up_write");
- __up_write(sem);
- rwsemtrace(sem,"Leaving up_write");
-}
+extern void up_write(struct rw_semaphore *sem);
/*
* downgrade write lock to read lock
*/
-static inline void downgrade_write(struct rw_semaphore *sem)
-{
- rwsemtrace(sem,"Entering downgrade_write");
- __downgrade_write(sem);
- rwsemtrace(sem,"Leaving downgrade_write");
-}
+extern void downgrade_write(struct rw_semaphore *sem);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+/*
+ * nested locking. NOTE: rwsems are not allowed to recurse
+ * (which occurs if the same task tries to acquire the same
+ * lock instance multiple times), but multiple locks of the
+ * same lock class might be taken, if the order of the locks
+ * is always the same. This ordering rule can be expressed
+ * to lockdep via the _nested() APIs, but enumerating the
+ * subclasses that are used. (If the nesting relationship is
+ * static then another method for expressing nested locking is
+ * the explicit definition of lock class keys and the use of
+ * lockdep_set_class() at lock initialization time.
+ * See Documentation/lockdep-design.txt for more details.)
+ */
+extern void down_read_nested(struct rw_semaphore *sem, int subclass);
+extern void down_write_nested(struct rw_semaphore *sem, int subclass);
+/*
+ * Take/release a lock when not the owner will release it.
+ *
+ * [ This API should be avoided as much as possible - the
+ * proper abstraction for this case is completions. ]
+ */
+extern void down_read_non_owner(struct rw_semaphore *sem);
+extern void up_read_non_owner(struct rw_semaphore *sem);
+#else
+# define down_read_nested(sem, subclass) down_read(sem)
+# define down_write_nested(sem, subclass) down_write(sem)
+# define down_read_non_owner(sem) down_read(sem)
+# define up_read_non_owner(sem) up_read(sem)
+#endif
#endif /* __KERNEL__ */
#endif /* _LINUX_RWSEM_H */