rw_semaphores: Add rw_anon_semaphores

Most of the rw_semaphores have struct owner semantics. i_alloc_sem and
two xfs ones are used as both semaphores and completions. That makes
it hard to convert for preempt-rt. Add an rw_anon_semaphores type
which is not converted on -rt.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 78 insertions, 26 deletions

diff --git a/arch/sh/include/asm/rwsem.h b/arch/sh/include/asm/rwsem.h
index 1987f3ea7f1b..ed8c771b2b47 100644
--- a/arch/sh/include/asm/rwsem.h
+++ b/arch/sh/include/asm/rwsem.h
@@ -19,7 +19,7 @@
 /*
  * the semaphore definition
  */
-struct rw_semaphore {
+struct rw_anon_semaphore {
 	long		count;
 #define RWSEM_UNLOCKED_VALUE		0x00000000
 #define RWSEM_ACTIVE_BIAS		0x00000001
@@ -35,35 +35,38 @@ struct rw_semaphore {
 };
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname }
+# define __RWSEM_ANON_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname }
 #else
-# define __RWSEM_DEP_MAP_INIT(lockname)
+# define __RWSEM_ANON_DEP_MAP_INIT(lockname)
 #endif
 
-#define __RWSEM_INITIALIZER(name) \
+#define __RWSEM_ANON_INITIALIZER(name) \
 	{ RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, \
 	  LIST_HEAD_INIT((name).wait_list) \
-	  __RWSEM_DEP_MAP_INIT(name) }
+	  __RWSEM_ANON_DEP_MAP_INIT(name) }
 
-#define DECLARE_RWSEM(name)		\
-	struct rw_semaphore name = __RWSEM_INITIALIZER(name)
+#define DECLARE_ANON_RWSEM(name)		\
+	struct rw_anon_semaphore name = __RWSEM_ANON_INITIALIZER(name)
 
-extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
+extern struct rw_anon_semaphore *
+rwsem_down_read_failed(struct rw_anon_semaphore *sem);
+extern struct rw_anon_semaphore *
+rwsem_down_write_failed(struct rw_anon_semaphore *sem);
+extern struct rw_anon_semaphore *rwsem_wake(struct rw_anon_semaphore *sem);
+extern struct rw_anon_semaphore *
+rwsem_downgrade_wake(struct rw_anon_semaphore *sem);
 
-extern void __init_rwsem(struct rw_semaphore *sem, const char *name,
-			 struct lock_class_key *key);
+extern void __init_anon_rwsem(struct rw_anon_semaphore *sem, const char *name,
+			      struct lock_class_key *key);
 
-#define init_rwsem(sem)				\
+#define init_anon_rwsem(sem)			\
 do {						\
 	static struct lock_class_key __key;	\
 						\
-	__init_rwsem((sem), #sem, &__key);	\
+	__init_anon_rwsem((sem), #sem, &__key);	\
 } while (0)
 
-static inline void init_rwsem(struct rw_semaphore *sem)
+static inline void init_anon_rwsem(struct rw_anon_semaphore *sem)
 {
 	sem->count = RWSEM_UNLOCKED_VALUE;
 	spin_lock_init(&sem->wait_lock);
@@ -73,7 +76,7 @@ static inline void init_rwsem(struct rw_semaphore *sem)
 /*
  * lock for reading
  */
-static inline void __down_read(struct rw_semaphore *sem)
+static inline void __down_read(struct rw_anon_semaphore *sem)
 {
 	if (atomic_inc_return((atomic_t *)(&sem->count)) > 0)
 		smp_wmb();
@@ -81,7 +84,7 @@ static inline void __down_read(struct rw_semaphore *sem)
 		rwsem_down_read_failed(sem);
 }
 
-static inline int __down_read_trylock(struct rw_semaphore *sem)
+static inline int __down_read_trylock(struct rw_anon_semaphore *sem)
 {
 	int tmp;
 
@@ -98,7 +101,7 @@ static inline int __down_read_trylock(struct rw_semaphore *sem)
 /*
  * lock for writing
  */
-static inline void __down_write(struct rw_semaphore *sem)
+static inline void __down_write(struct rw_anon_semaphore *sem)
 {
 	int tmp;
 
@@ -110,7 +113,7 @@ static inline void __down_write(struct rw_semaphore *sem)
 		rwsem_down_write_failed(sem);
 }
 
-static inline int __down_write_trylock(struct rw_semaphore *sem)
+static inline int __down_write_trylock(struct rw_anon_semaphore *sem)
 {
 	int tmp;
 
@@ -123,7 +126,7 @@ static inline int __down_write_trylock(struct rw_semaphore *sem)
 /*
  * unlock after reading
  */
-static inline void __up_read(struct rw_semaphore *sem)
+static inline void __up_read(struct rw_anon_semaphore *sem)
 {
 	int tmp;
 
@@ -136,7 +139,7 @@ static inline void __up_read(struct rw_semaphore *sem)
 /*
  * unlock after writing
  */
-static inline void __up_write(struct rw_semaphore *sem)
+static inline void __up_write(struct rw_anon_semaphore *sem)
 {
 	smp_wmb();
 	if (atomic_sub_return(RWSEM_ACTIVE_WRITE_BIAS,
@@ -147,7 +150,7 @@ static inline void __up_write(struct rw_semaphore *sem)
 /*
  * implement atomic add functionality
  */
-static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem)
+static inline void rwsem_atomic_add(int delta, struct rw_anon_semaphore *sem)
 {
 	atomic_add(delta, (atomic_t *)(&sem->count));
 }
@@ -155,7 +158,7 @@ static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem)
 /*
  * downgrade write lock to read lock
  */
-static inline void __downgrade_write(struct rw_semaphore *sem)
+static inline void __downgrade_write(struct rw_anon_semaphore *sem)
 {
 	int tmp;
 
@@ -165,7 +168,8 @@ static inline void __downgrade_write(struct rw_semaphore *sem)
 		rwsem_downgrade_wake(sem);
 }
 
-static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
+static inline void
+ __down_write_nested(struct rw_anon_semaphore *sem, int subclass)
 {
 	__down_write(sem);
 }
@@ -173,12 +177,60 @@ static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
 /*
  * implement exchange and add functionality
  */
-static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
+static inline int rwsem_atomic_update(int delta, struct rw_anon_semaphore *sem)
 {
 	smp_mb();
 	return atomic_add_return(delta, (atomic_t *)(&sem->count));
 }
 
+static inline int anon_rwsem_is_locked(struct rw_anon_semaphore *sem)
+{
+	return (sem->count != 0);
+}
+
+struct rw_semaphore {
+	long		count;
+	spinlock_t		wait_lock;
+	struct list_head	wait_list;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map	dep_map;
+#endif
+};
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname }
+#else
+# define __RWSEM_DEP_MAP_INIT(lockname)
+#endif
+
+#define __RWSEM_INITIALIZER(name) \
+	{ RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, \
+	  LIST_HEAD_INIT((name).wait_list) \
+	  __RWSEM_DEP_MAP_INIT(name) }
+
+#define DECLARE_RWSEM(name)		\
+	struct rw_semaphore name = __RWSEM_INITIALIZER(name)
+
+static inline void __init_rwsem(struct rw_semaphore *sem, const char *name,
+				struct lock_class_key *key)
+{
+	__init_anon_rwsem((struct rw_anon_semaphore *)sem, name, key);
+}
+
+#define init_rwsem(sem)				\
+do {						\
+	static struct lock_class_key __key;	\
+						\
+	__init_rwsem((sem), #sem, &__key);	\
+} while (0)
+
+static inline void init_rwsem(struct rw_semaphore *sem)
+{
+	sem->count = RWSEM_UNLOCKED_VALUE;
+	spin_lock_init(&sem->wait_lock);
+	INIT_LIST_HEAD(&sem->wait_list);
+}
+
 static inline int rwsem_is_locked(struct rw_semaphore *sem)
 {
 	return (sem->count != 0);