1 files changed, 68 insertions, 10 deletions

diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index a66038d88878..426e98e0b675 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -16,6 +16,19 @@
 #include <linux/spinlock.h>
 #include <linux/atomic.h>
 #include <linux/err.h>
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define __RWSEM_DEP_MAP_INIT(lockname)			\
+	.dep_map = {					\
+		.name = #lockname,			\
+		.wait_type_inner = LD_WAIT_SLEEP,	\
+	},
+#else
+# define __RWSEM_DEP_MAP_INIT(lockname)
+#endif
+
+#ifndef CONFIG_PREEMPT_RT
+
 #ifdef CONFIG_RWSEM_SPIN_ON_OWNER
 #include <linux/osq_lock.h>
 #endif
@@ -64,16 +77,6 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem)
 
 /* Common initializer macros and functions */
 
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define __RWSEM_DEP_MAP_INIT(lockname)			\
-	.dep_map = {					\
-		.name = #lockname,			\
-		.wait_type_inner = LD_WAIT_SLEEP,	\
-	},
-#else
-# define __RWSEM_DEP_MAP_INIT(lockname)
-#endif
-
 #ifdef CONFIG_DEBUG_RWSEMS
 # define __RWSEM_DEBUG_INIT(lockname) .magic = &lockname,
 #else
@@ -119,6 +122,61 @@ static inline int rwsem_is_contended(struct rw_semaphore *sem)
 	return !list_empty(&sem->wait_list);
 }
 
+#else /* !CONFIG_PREEMPT_RT */
+
+#include <linux/rwbase_rt.h>
+
+struct rw_semaphore {
+	struct rwbase_rt	rwbase;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map	dep_map;
+#endif
+};
+
+#define __RWSEM_INITIALIZER(name)				\
+	{							\
+		.rwbase = __RWBASE_INITIALIZER(name),		\
+		__RWSEM_DEP_MAP_INIT(name)			\
+	}
+
+#define DECLARE_RWSEM(lockname) \
+	struct rw_semaphore lockname = __RWSEM_INITIALIZER(lockname)
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+extern void  __rwsem_init(struct rw_semaphore *rwsem, const char *name,
+			  struct lock_class_key *key);
+#else
+static inline void  __rwsem_init(struct rw_semaphore *rwsem, const char *name,
+				 struct lock_class_key *key)
+{
+}
+#endif
+
+#define init_rwsem(sem)						\
+do {								\
+	static struct lock_class_key __key;			\
+								\
+	init_rwbase_rt(&(sem)->rwbase);			\
+	__rwsem_init((sem), #sem, &__key);			\
+} while (0)
+
+static __always_inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+	return rw_base_is_locked(&sem->rwbase);
+}
+
+static __always_inline int rwsem_is_contended(struct rw_semaphore *sem)
+{
+	return rw_base_is_contended(&sem->rwbase);
+}
+
+#endif /* CONFIG_PREEMPT_RT */
+
+/*
+ * The functions below are the same for all rwsem implementations including
+ * the RT specific variant.
+ */
+
 /*
  * lock for reading
  */