From: Mike Galbraith <mgalbraith@suse.de>
Date: Wed Aug  2 10:55:41 CEST 2017
Subject: locking: Cleanup local locks
Patch-mainline: Never, RT specific
References: SLE Realtime Extension

locking: Cleanup local locks

1. Remove unneeded local_irq_lock.flags.
2. Make local_lock_irq() spin_lock/unlock_irq() with PREEMPT_RTB
3. Make local_lock_irqsave/on() disable irqs for PREEMPT_RTB without
   without mucking about with remote cpu local_irq_lock.flags in the
   local_lock_irqsave_on() case.

Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
---
 include/linux/locallock.h |   44 ++++++++++++++++++++++++--------------------
 1 file changed, 24 insertions(+), 20 deletions(-)

--- a/include/linux/locallock.h
+++ b/include/linux/locallock.h
@@ -19,7 +19,6 @@ struct local_irq_lock {
 	spinlock_t		lock;
 	struct task_struct	*owner;
 	int			nestcnt;
-	unsigned long		flags;
 };
 
 #define DEFINE_LOCAL_IRQ_LOCK(lvar)					\
@@ -46,10 +45,14 @@ struct local_irq_lock {
 # define spin_lock_local(lock)			rt_spin_lock__no_mg(lock)
 # define spin_trylock_local(lock)		rt_spin_trylock__no_mg(lock)
 # define spin_unlock_local(lock)		rt_spin_unlock__no_mg(lock)
+# define spin_lock_irq_local(lock)		rt_spin_lock__no_mg(lock)
+# define spin_unlock_irq_local(lock)		rt_spin_unlock__no_mg(lock)
 #else
 # define spin_lock_local(lock)			spin_lock(lock)
 # define spin_trylock_local(lock)		spin_trylock(lock)
 # define spin_unlock_local(lock)		spin_unlock(lock)
+# define spin_lock_irq_local(lock)		spin_lock_irq(lock)
+# define spin_unlock_irq_local(lock)		spin_unlock_irq(lock)
 #endif
 
 static inline void __local_lock(struct local_irq_lock *lv)
@@ -63,10 +66,10 @@ static inline void __local_lock(struct l
 	lv->nestcnt++;
 }
 
-#define local_lock(lvar)					\
+#define local_lock(lvar)						\
 	do { __local_lock(&get_local_var(lvar)); } while (0)
 
-#define local_lock_on(lvar, cpu)				\
+#define local_lock_on(lvar, cpu)					\
 	do { __local_lock(&per_cpu(lvar, cpu)); } while (0)
 
 static inline int __local_trylock(struct local_irq_lock *lv)
@@ -101,18 +104,18 @@ static inline void __local_unlock(struct
 	spin_unlock_local(&lv->lock);
 }
 
-#define local_unlock(lvar)					\
-	do {							\
-		__local_unlock(this_cpu_ptr(&lvar));		\
-		put_local_var(lvar);				\
+#define local_unlock(lvar)						\
+	do {								\
+		__local_unlock(this_cpu_ptr(&lvar));			\
+		put_local_var(lvar);					\
 	} while (0)
 
-#define local_unlock_on(lvar, cpu)                       \
+#define local_unlock_on(lvar, cpu)					\
 	do { __local_unlock(&per_cpu(lvar, cpu)); } while (0)
 
 static inline void __local_lock_irq(struct local_irq_lock *lv)
 {
-	spin_lock_irqsave(&lv->lock, lv->flags);
+	spin_lock_irq_local(&lv->lock);
 	LL_WARN(lv->owner);
 	LL_WARN(lv->nestcnt);
 	lv->owner = current;
@@ -131,7 +134,7 @@ static inline void __local_unlock_irq(st
 	LL_WARN(lv->owner != current);
 	lv->owner = NULL;
 	lv->nestcnt = 0;
-	spin_unlock_irq(&lv->lock);
+	spin_unlock_irq_local(&lv->lock);
 }
 
 #define local_unlock_irq(lvar)						\
@@ -148,7 +151,7 @@ static inline void __local_unlock_irq(st
 static inline int __local_lock_irqsave(struct local_irq_lock *lv)
 {
 	if (lv->owner != current) {
-		__local_lock_irq(lv);
+		__local_lock(lv);
 		return 0;
 	} else {
 		lv->nestcnt++;
@@ -156,21 +159,20 @@ static inline int __local_lock_irqsave(s
 	}
 }
 
-#define local_lock_irqsave(lvar, _flags)				\
+#define local_lock_irqsave(lvar, flags)					\
 	do {								\
+		local_irq_save_nort(flags);				\
 		if (__local_lock_irqsave(&get_local_var(lvar)))		\
 			put_local_var(lvar);				\
-		_flags = __this_cpu_read(lvar.flags);			\
 	} while (0)
 
-#define local_lock_irqsave_on(lvar, _flags, cpu)			\
+#define local_lock_irqsave_on(lvar, flags, cpu)				\
 	do {								\
+		local_irq_save_nort(flags);				\
 		__local_lock_irqsave(&per_cpu(lvar, cpu));		\
-		_flags = per_cpu(lvar, cpu).flags;			\
 	} while (0)
 
-static inline int __local_unlock_irqrestore(struct local_irq_lock *lv,
-					    unsigned long flags)
+static inline int __local_unlock_irqrestore(struct local_irq_lock *lv)
 {
 	LL_WARN(!lv->nestcnt);
 	LL_WARN(lv->owner != current);
@@ -178,19 +180,21 @@ static inline int __local_unlock_irqrest
 		return 0;
 
 	lv->owner = NULL;
-	spin_unlock_irqrestore(&lv->lock, lv->flags);
+	spin_unlock_local(&lv->lock);
 	return 1;
 }
 
 #define local_unlock_irqrestore(lvar, flags)				\
 	do {								\
-		if (__local_unlock_irqrestore(this_cpu_ptr(&lvar), flags)) \
+		if (__local_unlock_irqrestore(this_cpu_ptr(&lvar)))	\
 			put_local_var(lvar);				\
+		local_irq_restore_nort(flags);				\
 	} while (0)
 
 #define local_unlock_irqrestore_on(lvar, flags, cpu)			\
 	do {								\
-		__local_unlock_irqrestore(&per_cpu(lvar, cpu), flags);	\
+		__local_unlock_irqrestore(&per_cpu(lvar, cpu));		\
+		local_irq_restore_nort(flags);				\
 	} while (0)
 
 #define local_spin_trylock_irq(lvar, lock)				\