[patch 1/2] rt: add local_lock_on and local_lock_irqsave_on to locallock.h

[Marcelo Tosatti <mtosatti@redhat.com>]

Re-add local_lock_on type functions to locallock.h (from the 5.4-RT 
tree).

To be used by remote page draining.

The original commit message is:

Introduce locallock. For !RT this maps to preempt_disable()/
local_irq_disable() so there is not much that changes. For RT this will
map to a spinlock. This makes preemption possible and locked "ressource"
gets the lockdep anotation it wouldn't have otherwise. The locks are
recursive for owner == current. Also, all locks user migrate_disable()
which ensures that the task is not migrated to another CPU while the lock
is held and the owner is preempted.

From: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

---
 include/linux/locallock.h |   25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

Index: linux-rt-devel/include/linux/locallock.h
===================================================================
--- linux-rt-devel.orig/include/linux/locallock.h
+++ linux-rt-devel/include/linux/locallock.h
@@ -51,6 +51,9 @@ static inline void __local_lock(struct l
 #define local_lock(lvar)					\
 	do { __local_lock(&get_local_var(lvar)); } while (0)
 
+#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)
 {
 	if (lv->owner != current && spin_trylock(&lv->lock)) {
@@ -92,6 +95,9 @@ static inline void __local_unlock(struct
 		put_local_var(lvar);				\
 	} while (0)
 
+#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);
@@ -104,6 +110,9 @@ static inline void __local_lock_irq(stru
 #define local_lock_irq(lvar)						\
 	do { __local_lock_irq(&get_local_var(lvar)); } while (0)
 
+#define local_lock_irq_on(lvar, cpu)					\
+	do { __local_lock_irq(&per_cpu(lvar, cpu)); } while (0)
+
 static inline void __local_unlock_irq(struct local_irq_lock *lv)
 {
 	LL_WARN(!lv->nestcnt);
@@ -119,6 +128,11 @@ static inline void __local_unlock_irq(st
 		put_local_var(lvar);					\
 	} while (0)
 
+#define local_unlock_irq_on(lvar, cpu)					\
+	do {								\
+		__local_unlock_irq(&per_cpu(lvar, cpu));		\
+	} while (0)
+
 static inline int __local_lock_irqsave(struct local_irq_lock *lv)
 {
 	if (lv->owner != current) {
@@ -137,6 +151,12 @@ static inline int __local_lock_irqsave(s
 		_flags = __this_cpu_read(lvar.flags);			\
 	} while (0)
 
+#define local_lock_irqsave_on(lvar, _flags, cpu)			\
+	do {								\
+		__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)
 {
@@ -156,6 +176,11 @@ static inline int __local_unlock_irqrest
 			put_local_var(lvar);				\
 	} while (0)
 
+#define local_unlock_irqrestore_on(lvar, flags, cpu)			\
+	do {								\
+		__local_unlock_irqrestore(&per_cpu(lvar, cpu), flags);	\
+	} while (0)
+
 #define local_spin_trylock_irq(lvar, lock)				\
 	({								\
 		int __locked;						\