[RFC PATCH 03/12] locking/lockdep: Add DEFINE_TERMINAL_SPINLOCK() and related macros

[Waiman Long]

Add new DEFINE_RAW_TERMINAL_SPINLOCK() and DEFINE_TERMINAL_SPINLOCK()
macro to define a raw terminal spinlock and a terminal spinlock.

Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
---
 include/linux/spinlock_types.h | 34 +++++++++++++++++++++++-----------
 kernel/printk/printk_safe.c    |  2 +-
 2 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/include/linux/spinlock_types.h b/include/linux/spinlock_types.h
index 24b4e6f..6a8086e 100644
--- a/include/linux/spinlock_types.h
+++ b/include/linux/spinlock_types.h
@@ -33,9 +33,10 @@
 #define SPINLOCK_OWNER_INIT	((void *)-1L)
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define SPIN_DEP_MAP_INIT(lockname)	.dep_map = { .name = #lockname }
+# define SPIN_DEP_MAP_INIT(lockname, f) .dep_map = { .name = #lockname, \
+						     .flags = f }
 #else
-# define SPIN_DEP_MAP_INIT(lockname)
+# define SPIN_DEP_MAP_INIT(lockname, f)
 #endif
 
 #ifdef CONFIG_DEBUG_SPINLOCK
@@ -47,16 +48,22 @@
 # 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_INITIALIZER(lockname, f)	\
+	{						\
+	.raw_lock = __ARCH_SPIN_LOCK_UNLOCKED,		\
+	SPIN_DEBUG_INIT(lockname)			\
+	SPIN_DEP_MAP_INIT(lockname, f) }
 
 #define __RAW_SPIN_LOCK_UNLOCKED(lockname)	\
-	(raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname)
+	(raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname, 0)
+
+#define __RAW_TERMINAL_SPIN_LOCK_UNLOCKED(lockname)	\
+	(raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname, \
+						     LOCKDEP_FLAG_TERMINAL)
 
 #define DEFINE_RAW_SPINLOCK(x)	raw_spinlock_t x = __RAW_SPIN_LOCK_UNLOCKED(x)
+#define DEFINE_RAW_TERMINAL_SPINLOCK(x)	\
+		raw_spinlock_t x = __RAW_TERMINAL_SPIN_LOCK_UNLOCKED(x)
 
 typedef struct spinlock {
 	union {
@@ -72,13 +79,18 @@
 	};
 } spinlock_t;
 
-#define __SPIN_LOCK_INITIALIZER(lockname) \
-	{ { .rlock = __RAW_SPIN_LOCK_INITIALIZER(lockname) } }
+#define __SPIN_LOCK_INITIALIZER(lockname, f) \
+	{ { .rlock = __RAW_SPIN_LOCK_INITIALIZER(lockname, f) } }
 
 #define __SPIN_LOCK_UNLOCKED(lockname) \
-	(spinlock_t ) __SPIN_LOCK_INITIALIZER(lockname)
+	(spinlock_t) __SPIN_LOCK_INITIALIZER(lockname, 0)
+
+#define __TERMINAL_SPIN_LOCK_UNLOCKED(lockname) \
+	(spinlock_t) __SPIN_LOCK_INITIALIZER(lockname, LOCKDEP_FLAG_TERMINAL)
 
 #define DEFINE_SPINLOCK(x)	spinlock_t x = __SPIN_LOCK_UNLOCKED(x)
+#define DEFINE_TERMINAL_SPINLOCK(x) \
+				spinlock_t x = __TERMINAL_SPIN_LOCK_UNLOCKED(x)
 
 #include <linux/rwlock_types.h>
 
diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c
index 0913b4d..8ff1033 100644
--- a/kernel/printk/printk_safe.c
+++ b/kernel/printk/printk_safe.c
@@ -192,7 +192,7 @@ static void report_message_lost(struct printk_safe_seq_buf *s)
 static void __printk_safe_flush(struct irq_work *work)
 {
 	static raw_spinlock_t read_lock =
-		__RAW_SPIN_LOCK_INITIALIZER(read_lock);
+		__RAW_SPIN_LOCK_UNLOCKED(read_lock);
 	struct printk_safe_seq_buf *s =
 		container_of(work, struct printk_safe_seq_buf, work);
 	unsigned long flags;
-- 
1.8.3.1