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

Waiman Long
2018-11-08T20:35:34Z

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@redhat.com>
---
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