locking: Implement new raw_spinlock

Now that the raw_spin name space is freed up, we can implement
raw_spinlock and the related functions which are used to annotate the
locks which are not converted to sleeping spinlocks in preempt-rt.

A side effect is that only such locks can be used with the low level
lock fsunctions which circumvent lockdep.

For !rt spin_* functions are mapped to the raw_spin* implementations.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Ingo Molnar <mingo@elte.hu>

include/linux/spinlock_api_smp.h

@@ -17,26 +17,29 @@
 
 int in_lock_functions(unsigned long addr);
 
-#define assert_spin_locked(x)	BUG_ON(!spin_is_locked(x))
+#define assert_raw_spin_locked(x)	BUG_ON(!raw_spin_is_locked(x))
 
-void __lockfunc _spin_lock(spinlock_t *lock)		__acquires(lock);
-void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass)
+void __lockfunc _spin_lock(raw_spinlock_t *lock)	__acquires(lock);
+void __lockfunc _spin_lock_nested(raw_spinlock_t *lock, int subclass)
 							__acquires(lock);
-void __lockfunc _spin_lock_nest_lock(spinlock_t *lock, struct lockdep_map *map)
+void __lockfunc
+_spin_lock_nest_lock(raw_spinlock_t *lock, struct lockdep_map *map)
 							__acquires(lock);
-void __lockfunc _spin_lock_bh(spinlock_t *lock)		__acquires(lock);
-void __lockfunc _spin_lock_irq(spinlock_t *lock)	__acquires(lock);
+void __lockfunc _spin_lock_bh(raw_spinlock_t *lock)	__acquires(lock);
+void __lockfunc _spin_lock_irq(raw_spinlock_t *lock)	__acquires(lock);
 
-unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
+unsigned long __lockfunc _spin_lock_irqsave(raw_spinlock_t *lock)
 							__acquires(lock);
-unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclass)
+unsigned long __lockfunc
+_spin_lock_irqsave_nested(raw_spinlock_t *lock, int subclass)
 							__acquires(lock);
-int __lockfunc _spin_trylock(spinlock_t *lock);
-int __lockfunc _spin_trylock_bh(spinlock_t *lock);
-void __lockfunc _spin_unlock(spinlock_t *lock)		__releases(lock);
-void __lockfunc _spin_unlock_bh(spinlock_t *lock)	__releases(lock);
-void __lockfunc _spin_unlock_irq(spinlock_t *lock)	__releases(lock);
-void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
+int __lockfunc _spin_trylock(raw_spinlock_t *lock);
+int __lockfunc _spin_trylock_bh(raw_spinlock_t *lock);
+void __lockfunc _spin_unlock(raw_spinlock_t *lock)	__releases(lock);
+void __lockfunc _spin_unlock_bh(raw_spinlock_t *lock)	__releases(lock);
+void __lockfunc _spin_unlock_irq(raw_spinlock_t *lock)	__releases(lock);
+void __lockfunc
+_spin_unlock_irqrestore(raw_spinlock_t *lock, unsigned long flags)
 							__releases(lock);
 
 #ifdef CONFIG_INLINE_SPIN_LOCK
@@ -79,7 +82,7 @@ void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
 #define _spin_unlock_irqrestore(lock, flags) __spin_unlock_irqrestore(lock, flags)
 #endif
 
-static inline int __spin_trylock(spinlock_t *lock)
+static inline int __spin_trylock(raw_spinlock_t *lock)
 {
 	preempt_disable();
 	if (_raw_spin_trylock(lock)) {
@@ -97,7 +100,7 @@ static inline int __spin_trylock(spinlock_t *lock)
  */
 #if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC)
 
-static inline unsigned long __spin_lock_irqsave(spinlock_t *lock)
+static inline unsigned long __spin_lock_irqsave(raw_spinlock_t *lock)
 {
 	unsigned long flags;
 
@@ -117,7 +120,7 @@ static inline unsigned long __spin_lock_irqsave(spinlock_t *lock)
 	return flags;
 }
 
-static inline void __spin_lock_irq(spinlock_t *lock)
+static inline void __spin_lock_irq(raw_spinlock_t *lock)
 {
 	local_irq_disable();
 	preempt_disable();
@@ -125,7 +128,7 @@ static inline void __spin_lock_irq(spinlock_t *lock)
 	LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
 }
 
-static inline void __spin_lock_bh(spinlock_t *lock)
+static inline void __spin_lock_bh(raw_spinlock_t *lock)
 {
 	local_bh_disable();
 	preempt_disable();
@@ -133,7 +136,7 @@ static inline void __spin_lock_bh(spinlock_t *lock)
 	LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
 }
 
-static inline void __spin_lock(spinlock_t *lock)
+static inline void __spin_lock(raw_spinlock_t *lock)
 {
 	preempt_disable();
 	spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
@@ -142,14 +145,14 @@ static inline void __spin_lock(spinlock_t *lock)
 
 #endif /* CONFIG_PREEMPT */
 
-static inline void __spin_unlock(spinlock_t *lock)
+static inline void __spin_unlock(raw_spinlock_t *lock)
 {
 	spin_release(&lock->dep_map, 1, _RET_IP_);
 	_raw_spin_unlock(lock);
 	preempt_enable();
 }
 
-static inline void __spin_unlock_irqrestore(spinlock_t *lock,
+static inline void __spin_unlock_irqrestore(raw_spinlock_t *lock,
 					    unsigned long flags)
 {
 	spin_release(&lock->dep_map, 1, _RET_IP_);
@@ -158,7 +161,7 @@ static inline void __spin_unlock_irqrestore(spinlock_t *lock,
 	preempt_enable();
 }
 
-static inline void __spin_unlock_irq(spinlock_t *lock)
+static inline void __spin_unlock_irq(raw_spinlock_t *lock)
 {
 	spin_release(&lock->dep_map, 1, _RET_IP_);
 	_raw_spin_unlock(lock);
@@ -166,7 +169,7 @@ static inline void __spin_unlock_irq(spinlock_t *lock)
 	preempt_enable();
 }
 
-static inline void __spin_unlock_bh(spinlock_t *lock)
+static inline void __spin_unlock_bh(raw_spinlock_t *lock)
 {
 	spin_release(&lock->dep_map, 1, _RET_IP_);
 	_raw_spin_unlock(lock);
@@ -174,7 +177,7 @@ static inline void __spin_unlock_bh(spinlock_t *lock)
 	local_bh_enable_ip((unsigned long)__builtin_return_address(0));
 }
 
-static inline int __spin_trylock_bh(spinlock_t *lock)
+static inline int __spin_trylock_bh(raw_spinlock_t *lock)
 {
 	local_bh_disable();
 	preempt_disable();

include/linux/spinlock_api_up.h

@@ -16,7 +16,7 @@
 
 #define in_lock_functions(ADDR)		0
 
-#define assert_spin_locked(lock)	do { (void)(lock); } while (0)
+#define assert_raw_spin_locked(lock)	do { (void)(lock); } while (0)
 
 /*
  * In the UP-nondebug case there's no real locking going on, so the

include/linux/spinlock_types.h

@@ -17,7 +17,7 @@
 
 #include <linux/lockdep.h>
 
-typedef struct {
+typedef struct raw_spinlock {
 	arch_spinlock_t raw_lock;
 #ifdef CONFIG_GENERIC_LOCKBREAK
 	unsigned int break_lock;
@@ -29,7 +29,7 @@ typedef struct {
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 	struct lockdep_map dep_map;
 #endif
-} spinlock_t;
+} raw_spinlock_t;
 
 #define SPINLOCK_MAGIC		0xdead4ead
 
@@ -42,18 +42,45 @@ typedef struct {
 #endif
 
 #ifdef CONFIG_DEBUG_SPINLOCK
-# define __SPIN_LOCK_UNLOCKED(lockname)					\
-	(spinlock_t)	{	.raw_lock = __ARCH_SPIN_LOCK_UNLOCKED,	\
-				.magic = SPINLOCK_MAGIC,		\
-				.owner = SPINLOCK_OWNER_INIT,		\
-				.owner_cpu = -1,			\
-				SPIN_DEP_MAP_INIT(lockname) }
+# define SPIN_DEBUG_INIT(lockname)		\
+	.magic = SPINLOCK_MAGIC,		\
+	.owner_cpu = -1,			\
+	.owner = SPINLOCK_OWNER_INIT,
 #else
-# define __SPIN_LOCK_UNLOCKED(lockname) \
-	(spinlock_t)	{	.raw_lock = __ARCH_SPIN_LOCK_UNLOCKED,	\
-				SPIN_DEP_MAP_INIT(lockname) }
+# define SPIN_DEBUG_INIT(lockname)
 #endif
 
+#define __RAW_SPIN_LOCK_INITIALIZER(lockname)	\
+	{					\
+	.raw_lock = __ARCH_SPIN_LOCK_UNLOCKED,	\
+	SPIN_DEBUG_INIT(lockname)		\
+	SPIN_DEP_MAP_INIT(lockname) }
+
+#define __RAW_SPIN_LOCK_UNLOCKED(lockname)	\
+	(raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname)
+
+#define DEFINE_RAW_SPINLOCK(x)	raw_spinlock_t x = __RAW_SPIN_LOCK_UNLOCKED(x)
+
+typedef struct spinlock {
+	union {
+		struct raw_spinlock rlock;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define LOCK_PADSIZE (offsetof(struct raw_spinlock, dep_map))
+		struct {
+			u8 __padding[LOCK_PADSIZE];
+			struct lockdep_map dep_map;
+		};
+#endif
+	};
+} spinlock_t;
+
+#define __SPIN_LOCK_INITIALIZER(lockname) \
+	{ { .rlock = __RAW_SPIN_LOCK_INITIALIZER(lockname) } }
+
+#define __SPIN_LOCK_UNLOCKED(lockname) \
+	(spinlock_t ) __SPIN_LOCK_INITIALIZER(lockname)
+
 /*
  * SPIN_LOCK_UNLOCKED defeats lockdep state tracking and is hence
  * deprecated.

kernel/mutex-debug.h

@@ -43,13 +43,13 @@ static inline void mutex_clear_owner(struct mutex *lock)
 							\
 		DEBUG_LOCKS_WARN_ON(in_interrupt());	\
 		local_irq_save(flags);			\
-		arch_spin_lock(&(lock)->raw_lock);	\
+		arch_spin_lock(&(lock)->rlock.raw_lock);\
 		DEBUG_LOCKS_WARN_ON(l->magic != l);	\
 	} while (0)
 
-#define spin_unlock_mutex(lock, flags)			\
-	do {						\
-		arch_spin_unlock(&(lock)->raw_lock);	\
-		local_irq_restore(flags);		\
-		preempt_check_resched();		\
+#define spin_unlock_mutex(lock, flags)				\
+	do {							\
+		arch_spin_unlock(&(lock)->rlock.raw_lock);	\
+		local_irq_restore(flags);			\
+		preempt_check_resched();			\
 	} while (0)

kernel/sched.c

@@ -884,7 +884,7 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
 {
 #ifdef CONFIG_DEBUG_SPINLOCK
 	/* this is a valid case when another task releases the spinlock */
-	rq->lock.owner = current;
+	rq->lock.rlock.owner = current;
 #endif
 	/*
 	 * If we are tracking spinlock dependencies then we have to

kernel/spinlock.c

@@ -32,6 +32,8 @@
  * include/linux/spinlock_api_smp.h
  */
 #else
+#define raw_read_can_lock(l)	read_can_lock(l)
+#define raw_write_can_lock(l)	write_can_lock(l)
 /*
  * We build the __lock_function inlines here. They are too large for
  * inlining all over the place, but here is only one user per function
@@ -52,7 +54,7 @@ void __lockfunc __##op##_lock(locktype##_t *lock)			\
 									\
 		if (!(lock)->break_lock)				\
 			(lock)->break_lock = 1;				\
-		while (!op##_can_lock(lock) && (lock)->break_lock)	\
+		while (!raw_##op##_can_lock(lock) && (lock)->break_lock)\
 			arch_##op##_relax(&lock->raw_lock);		\
 	}								\
 	(lock)->break_lock = 0;						\
@@ -72,7 +74,7 @@ unsigned long __lockfunc __##op##_lock_irqsave(locktype##_t *lock)	\
 									\
 		if (!(lock)->break_lock)				\
 			(lock)->break_lock = 1;				\
-		while (!op##_can_lock(lock) && (lock)->break_lock)	\
+		while (!raw_##op##_can_lock(lock) && (lock)->break_lock)\
 			arch_##op##_relax(&lock->raw_lock);		\
 	}								\
 	(lock)->break_lock = 0;						\
@@ -107,14 +109,14 @@ void __lockfunc __##op##_lock_bh(locktype##_t *lock)			\
  *         __[spin|read|write]_lock_irqsave()
  *         __[spin|read|write]_lock_bh()
  */
-BUILD_LOCK_OPS(spin, spinlock);
+BUILD_LOCK_OPS(spin, raw_spinlock);
 BUILD_LOCK_OPS(read, rwlock);
 BUILD_LOCK_OPS(write, rwlock);
 
 #endif
 
 #ifndef CONFIG_INLINE_SPIN_TRYLOCK
-int __lockfunc _spin_trylock(spinlock_t *lock)
+int __lockfunc _spin_trylock(raw_spinlock_t *lock)
 {
 	return __spin_trylock(lock);
 }
@@ -122,7 +124,7 @@ EXPORT_SYMBOL(_spin_trylock);
 #endif
 
 #ifndef CONFIG_INLINE_SPIN_TRYLOCK_BH
-int __lockfunc _spin_trylock_bh(spinlock_t *lock)
+int __lockfunc _spin_trylock_bh(raw_spinlock_t *lock)
 {
 	return __spin_trylock_bh(lock);
 }
@@ -130,7 +132,7 @@ EXPORT_SYMBOL(_spin_trylock_bh);
 #endif
 
 #ifndef CONFIG_INLINE_SPIN_LOCK
-void __lockfunc _spin_lock(spinlock_t *lock)
+void __lockfunc _spin_lock(raw_spinlock_t *lock)
 {
 	__spin_lock(lock);
 }
@@ -138,7 +140,7 @@ EXPORT_SYMBOL(_spin_lock);
 #endif
 
 #ifndef CONFIG_INLINE_SPIN_LOCK_IRQSAVE
-unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
+unsigned long __lockfunc _spin_lock_irqsave(raw_spinlock_t *lock)
 {
 	return __spin_lock_irqsave(lock);
 }
@@ -146,7 +148,7 @@ EXPORT_SYMBOL(_spin_lock_irqsave);
 #endif
 
 #ifndef CONFIG_INLINE_SPIN_LOCK_IRQ
-void __lockfunc _spin_lock_irq(spinlock_t *lock)
+void __lockfunc _spin_lock_irq(raw_spinlock_t *lock)
 {
 	__spin_lock_irq(lock);
 }
@@ -154,7 +156,7 @@ EXPORT_SYMBOL(_spin_lock_irq);
 #endif
 
 #ifndef CONFIG_INLINE_SPIN_LOCK_BH
-void __lockfunc _spin_lock_bh(spinlock_t *lock)
+void __lockfunc _spin_lock_bh(raw_spinlock_t *lock)
 {
 	__spin_lock_bh(lock);
 }
@@ -162,7 +164,7 @@ EXPORT_SYMBOL(_spin_lock_bh);
 #endif
 
 #ifndef CONFIG_INLINE_SPIN_UNLOCK
-void __lockfunc _spin_unlock(spinlock_t *lock)
+void __lockfunc _spin_unlock(raw_spinlock_t *lock)
 {
 	__spin_unlock(lock);
 }
@@ -170,7 +172,7 @@ EXPORT_SYMBOL(_spin_unlock);
 #endif
 
 #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQRESTORE
-void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
+void __lockfunc _spin_unlock_irqrestore(raw_spinlock_t *lock, unsigned long flags)
 {
 	__spin_unlock_irqrestore(lock, flags);
 }
@@ -178,7 +180,7 @@ EXPORT_SYMBOL(_spin_unlock_irqrestore);
 #endif
 
 #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQ
-void __lockfunc _spin_unlock_irq(spinlock_t *lock)
+void __lockfunc _spin_unlock_irq(raw_spinlock_t *lock)
 {
 	__spin_unlock_irq(lock);
 }
@@ -186,7 +188,7 @@ EXPORT_SYMBOL(_spin_unlock_irq);
 #endif
 
 #ifndef CONFIG_INLINE_SPIN_UNLOCK_BH
-void __lockfunc _spin_unlock_bh(spinlock_t *lock)
+void __lockfunc _spin_unlock_bh(raw_spinlock_t *lock)
 {
 	__spin_unlock_bh(lock);
 }
@@ -339,7 +341,7 @@ EXPORT_SYMBOL(_write_unlock_bh);
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 
-void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass)
+void __lockfunc _spin_lock_nested(raw_spinlock_t *lock, int subclass)
 {
 	preempt_disable();
 	spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
@@ -347,7 +349,7 @@ void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass)
 }
 EXPORT_SYMBOL(_spin_lock_nested);
 
-unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock,
+unsigned long __lockfunc _spin_lock_irqsave_nested(raw_spinlock_t *lock,
 						   int subclass)
 {
 	unsigned long flags;
@@ -361,7 +363,7 @@ unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock,
 }
 EXPORT_SYMBOL(_spin_lock_irqsave_nested);
 
-void __lockfunc _spin_lock_nest_lock(spinlock_t *lock,
+void __lockfunc _spin_lock_nest_lock(raw_spinlock_t *lock,
 				     struct lockdep_map *nest_lock)
 {
 	preempt_disable();

lib/spinlock_debug.c

@@ -13,8 +13,8 @@
 #include <linux/delay.h>
 #include <linux/module.h>
 
-void __spin_lock_init(spinlock_t *lock, const char *name,
-		      struct lock_class_key *key)
+void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name,
+			  struct lock_class_key *key)
 {
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 	/*
@@ -29,7 +29,7 @@ void __spin_lock_init(spinlock_t *lock, const char *name,
 	lock->owner_cpu = -1;
 }
 
-EXPORT_SYMBOL(__spin_lock_init);
+EXPORT_SYMBOL(__raw_spin_lock_init);
 
 void __rwlock_init(rwlock_t *lock, const char *name,
 		   struct lock_class_key *key)
@@ -49,7 +49,7 @@ void __rwlock_init(rwlock_t *lock, const char *name,
 
 EXPORT_SYMBOL(__rwlock_init);
 
-static void spin_bug(spinlock_t *lock, const char *msg)
+static void spin_bug(raw_spinlock_t *lock, const char *msg)
 {
 	struct task_struct *owner = NULL;
 
@@ -73,7 +73,7 @@ static void spin_bug(spinlock_t *lock, const char *msg)
 #define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg)
 
 static inline void
-debug_spin_lock_before(spinlock_t *lock)
+debug_spin_lock_before(raw_spinlock_t *lock)
 {
 	SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic");
 	SPIN_BUG_ON(lock->owner == current, lock, "recursion");
@@ -81,16 +81,16 @@ debug_spin_lock_before(spinlock_t *lock)
 							lock, "cpu recursion");
 }
 
-static inline void debug_spin_lock_after(spinlock_t *lock)
+static inline void debug_spin_lock_after(raw_spinlock_t *lock)
 {
 	lock->owner_cpu = raw_smp_processor_id();
 	lock->owner = current;
 }
 
-static inline void debug_spin_unlock(spinlock_t *lock)
+static inline void debug_spin_unlock(raw_spinlock_t *lock)
 {
 	SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic");
-	SPIN_BUG_ON(!spin_is_locked(lock), lock, "already unlocked");
+	SPIN_BUG_ON(!raw_spin_is_locked(lock), lock, "already unlocked");
 	SPIN_BUG_ON(lock->owner != current, lock, "wrong owner");
 	SPIN_BUG_ON(lock->owner_cpu != raw_smp_processor_id(),
 							lock, "wrong CPU");
@@ -98,7 +98,7 @@ static inline void debug_spin_unlock(spinlock_t *lock)
 	lock->owner_cpu = -1;
 }
 
-static void __spin_lock_debug(spinlock_t *lock)
+static void __spin_lock_debug(raw_spinlock_t *lock)
 {
 	u64 i;
 	u64 loops = loops_per_jiffy * HZ;
@@ -125,7 +125,7 @@ static void __spin_lock_debug(spinlock_t *lock)
 	}
 }
 
-void _raw_spin_lock(spinlock_t *lock)
+void _raw_spin_lock(raw_spinlock_t *lock)
 {
 	debug_spin_lock_before(lock);
 	if (unlikely(!arch_spin_trylock(&lock->raw_lock)))
@@ -133,7 +133,7 @@ void _raw_spin_lock(spinlock_t *lock)
 	debug_spin_lock_after(lock);
 }
 
-int _raw_spin_trylock(spinlock_t *lock)
+int _raw_spin_trylock(raw_spinlock_t *lock)
 {
 	int ret = arch_spin_trylock(&lock->raw_lock);
 
@@ -148,7 +148,7 @@ int _raw_spin_trylock(spinlock_t *lock)
 	return ret;
 }
 
-void _raw_spin_unlock(spinlock_t *lock)
+void _raw_spin_unlock(raw_spinlock_t *lock)
 {
 	debug_spin_unlock(lock);
 	arch_spin_unlock(&lock->raw_lock);