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>

1 files changed, 38 insertions, 11 deletions

diff --git a/include/linux/spinlock_types.h b/include/linux/spinlock_types.h
index 7dadce303ebf..851b7783720d 100644
--- a/include/linux/spinlock_types.h
+++ b/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.