patches/rt-locking--Simplify-rt-rwlock.patch

Subject: rt/locking: Simplify rt rwlock
From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 28 Jul 2017 15:05:51 +0200

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 include/linux/rwlock_rt.h |   21 +++++++++++++--------
 kernel/locking/rt.c       |   23 ++---------------------
 2 files changed, 15 insertions(+), 29 deletions(-)

--- a/include/linux/rwlock_rt.h
+++ b/include/linux/rwlock_rt.h
@@ -9,37 +9,42 @@
 do {							\
 	static struct lock_class_key __key;		\
 							\
-	rt_mutex_init(&(rwl)->lock);			\
 	__rt_rwlock_init(rwl, #rwl, &__key);		\
 } while (0)
 
 extern void __lockfunc rt_write_lock(rwlock_t *rwlock);
 extern void __lockfunc rt_read_lock(rwlock_t *rwlock);
 extern int __lockfunc rt_write_trylock(rwlock_t *rwlock);
-extern int __lockfunc rt_write_trylock_irqsave(rwlock_t *trylock, unsigned long *flags);
 extern int __lockfunc rt_read_trylock(rwlock_t *rwlock);
 extern void __lockfunc rt_write_unlock(rwlock_t *rwlock);
 extern void __lockfunc rt_read_unlock(rwlock_t *rwlock);
-extern unsigned long __lockfunc rt_write_lock_irqsave(rwlock_t *rwlock);
-extern unsigned long __lockfunc rt_read_lock_irqsave(rwlock_t *rwlock);
 extern void __rt_rwlock_init(rwlock_t *rwlock, char *name, struct lock_class_key *key);
 
 #define read_trylock(lock)	__cond_lock(lock, rt_read_trylock(lock))
 #define write_trylock(lock)	__cond_lock(lock, rt_write_trylock(lock))
 
-#define write_trylock_irqsave(lock, flags)	\
-	__cond_lock(lock, rt_write_trylock_irqsave(lock, &flags))
+static inline int __write_trylock_rt_irqsave(rwlock_t *lock, unsigned long *flags)
+{
+	/* XXX ARCH_IRQ_ENABLED */
+	*flags = 0;
+	return rt_write_trylock(lock);
+}
+
+#define write_trylock_irqsave(lock, flags)		\
+	__cond_lock(lock, __write_trylock_rt_irqsave(lock, &(flags)))
 
 #define read_lock_irqsave(lock, flags)			\
 	do {						\
 		typecheck(unsigned long, flags);	\
-		flags = rt_read_lock_irqsave(lock);	\
+		rt_read_lock(lock);			\
+		flags = 0;				\
 	} while (0)
 
 #define write_lock_irqsave(lock, flags)			\
 	do {						\
 		typecheck(unsigned long, flags);	\
-		flags = rt_write_lock_irqsave(lock);	\
+		rt_write_lock(lock);			\
+		flags = 0;				\
 	} while (0)
 
 #define read_lock(lock)		rt_read_lock(lock)
--- a/kernel/locking/rt.c
+++ b/kernel/locking/rt.c
@@ -215,13 +215,6 @@ int __lockfunc rt_write_trylock(rwlock_t
 }
 EXPORT_SYMBOL(rt_write_trylock);
 
-int __lockfunc rt_write_trylock_irqsave(rwlock_t *rwlock, unsigned long *flags)
-{
-	*flags = 0;
-	return rt_write_trylock(rwlock);
-}
-EXPORT_SYMBOL(rt_write_trylock_irqsave);
-
 int __lockfunc rt_read_trylock(rwlock_t *rwlock)
 {
 	struct rt_mutex *lock = &rwlock->lock;
@@ -273,22 +266,10 @@ void __lockfunc rt_read_unlock(rwlock_t
 }
 EXPORT_SYMBOL(rt_read_unlock);
 
-unsigned long __lockfunc rt_write_lock_irqsave(rwlock_t *rwlock)
-{
-	rt_write_lock(rwlock);
-	return 0;
-}
-EXPORT_SYMBOL(rt_write_lock_irqsave);
-
-unsigned long __lockfunc rt_read_lock_irqsave(rwlock_t *rwlock)
-{
-	rt_read_lock(rwlock);
-	return 0;
-}
-EXPORT_SYMBOL(rt_read_lock_irqsave);
-
 void __rt_rwlock_init(rwlock_t *rwlock, char *name, struct lock_class_key *key)
 {
+	rt_mutex_init(&rwlock->lock);
+
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 	/*
 	 * Make sure we are not reinitializing a held lock: