locking: Move spinlock function bodies to header file

Move spinlock function bodies to header file by creating a
static inline version of each variant. Use the inline version
on the out-of-line code.

This shouldn't make any difference besides that the spinlock
code can now be used to generate inlined spinlock code.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Horst Hartmann <horsth@linux.vnet.ibm.com>
Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: <linux-arch@vger.kernel.org>
LKML-Reference: <20090831124417.859022429@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 300 insertions, 155 deletions

diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index 4be57ab03478..da76a06556bd 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -143,15 +143,6 @@ static inline void smp_mb__after_lock(void) { smp_mb(); }
  */
 #define spin_unlock_wait(lock)  __raw_spin_unlock_wait(&(lock)->raw_lock)
 
-/*
- * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
- */
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
-# include <linux/spinlock_api_smp.h>
-#else
-# include <linux/spinlock_api_up.h>
-#endif
-
 #ifdef CONFIG_DEBUG_SPINLOCK
  extern void _raw_spin_lock(spinlock_t *lock);
 #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
@@ -380,4 +371,13 @@ extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
  */
 #define spin_can_lock(lock)     (!spin_is_locked(lock))
 
+/*
+ * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
+ */
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+# include <linux/spinlock_api_smp.h>
+#else
+# include <linux/spinlock_api_up.h>
+#endif
+
 #endif /* __LINUX_SPINLOCK_H */
diff --git a/include/linux/spinlock_api_smp.h b/include/linux/spinlock_api_smp.h
index d79845d034b5..6b108f5fb149 100644
--- a/include/linux/spinlock_api_smp.h
+++ b/include/linux/spinlock_api_smp.h
@@ -60,4 +60,267 @@ void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
 void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
                                                         __releases(lock);
 
+static inline int __spin_trylock(spinlock_t *lock)
+{
+        preempt_disable();
+        if (_raw_spin_trylock(lock)) {
+                spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+                return 1;
+        }
+        preempt_enable();
+        return 0;
+}
+
+static inline int __read_trylock(rwlock_t *lock)
+{
+        preempt_disable();
+        if (_raw_read_trylock(lock)) {
+                rwlock_acquire_read(&lock->dep_map, 0, 1, _RET_IP_);
+                return 1;
+        }
+        preempt_enable();
+        return 0;
+}
+
+static inline int __write_trylock(rwlock_t *lock)
+{
+        preempt_disable();
+        if (_raw_write_trylock(lock)) {
+                rwlock_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+                return 1;
+        }
+        preempt_enable();
+        return 0;
+}
+
+/*
+ * If lockdep is enabled then we use the non-preemption spin-ops
+ * even on CONFIG_PREEMPT, because lockdep assumes that interrupts are
+ * not re-enabled during lock-acquire (which the preempt-spin-ops do):
+ */
+#if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC)
+
+static inline void __read_lock(rwlock_t *lock)
+{
+        preempt_disable();
+        rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
+        LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
+}
+
+static inline unsigned long __spin_lock_irqsave(spinlock_t *lock)
+{
+        unsigned long flags;
+
+        local_irq_save(flags);
+        preempt_disable();
+        spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+        /*
+         * On lockdep we dont want the hand-coded irq-enable of
+         * _raw_spin_lock_flags() code, because lockdep assumes
+         * that interrupts are not re-enabled during lock-acquire:
+         */
+#ifdef CONFIG_LOCKDEP
+        LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
+#else
+        _raw_spin_lock_flags(lock, &flags);
+#endif
+        return flags;
+}
+
+static inline void __spin_lock_irq(spinlock_t *lock)
+{
+        local_irq_disable();
+        preempt_disable();
+        spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+        LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
+}
+
+static inline void __spin_lock_bh(spinlock_t *lock)
+{
+        local_bh_disable();
+        preempt_disable();
+        spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+        LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
+}
+
+static inline unsigned long __read_lock_irqsave(rwlock_t *lock)
+{
+        unsigned long flags;
+
+        local_irq_save(flags);
+        preempt_disable();
+        rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
+        LOCK_CONTENDED_FLAGS(lock, _raw_read_trylock, _raw_read_lock,
+                             _raw_read_lock_flags, &flags);
+        return flags;
+}
+
+static inline void __read_lock_irq(rwlock_t *lock)
+{
+        local_irq_disable();
+        preempt_disable();
+        rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
+        LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
+}
+
+static inline void __read_lock_bh(rwlock_t *lock)
+{
+        local_bh_disable();
+        preempt_disable();
+        rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
+        LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
+}
+
+static inline unsigned long __write_lock_irqsave(rwlock_t *lock)
+{
+        unsigned long flags;
+
+        local_irq_save(flags);
+        preempt_disable();
+        rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+        LOCK_CONTENDED_FLAGS(lock, _raw_write_trylock, _raw_write_lock,
+                             _raw_write_lock_flags, &flags);
+        return flags;
+}
+
+static inline void __write_lock_irq(rwlock_t *lock)
+{
+        local_irq_disable();
+        preempt_disable();
+        rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+        LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
+}
+
+static inline void __write_lock_bh(rwlock_t *lock)
+{
+        local_bh_disable();
+        preempt_disable();
+        rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+        LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
+}
+
+static inline void __spin_lock(spinlock_t *lock)
+{
+        preempt_disable();
+        spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+        LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
+}
+
+static inline void __write_lock(rwlock_t *lock)
+{
+        preempt_disable();
+        rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+        LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
+}
+
+#endif /* CONFIG_PREEMPT */
+
+static inline void __spin_unlock(spinlock_t *lock)
+{
+        spin_release(&lock->dep_map, 1, _RET_IP_);
+        _raw_spin_unlock(lock);
+        preempt_enable();
+}
+
+static inline void __write_unlock(rwlock_t *lock)
+{
+        rwlock_release(&lock->dep_map, 1, _RET_IP_);
+        _raw_write_unlock(lock);
+        preempt_enable();
+}
+
+static inline void __read_unlock(rwlock_t *lock)
+{
+        rwlock_release(&lock->dep_map, 1, _RET_IP_);
+        _raw_read_unlock(lock);
+        preempt_enable();
+}
+
+static inline void __spin_unlock_irqrestore(spinlock_t *lock,
+                                            unsigned long flags)
+{
+        spin_release(&lock->dep_map, 1, _RET_IP_);
+        _raw_spin_unlock(lock);
+        local_irq_restore(flags);
+        preempt_enable();
+}
+
+static inline void __spin_unlock_irq(spinlock_t *lock)
+{
+        spin_release(&lock->dep_map, 1, _RET_IP_);
+        _raw_spin_unlock(lock);
+        local_irq_enable();
+        preempt_enable();
+}
+
+static inline void __spin_unlock_bh(spinlock_t *lock)
+{
+        spin_release(&lock->dep_map, 1, _RET_IP_);
+        _raw_spin_unlock(lock);
+        preempt_enable_no_resched();
+        local_bh_enable_ip((unsigned long)__builtin_return_address(0));
+}
+
+static inline void __read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
+{
+        rwlock_release(&lock->dep_map, 1, _RET_IP_);
+        _raw_read_unlock(lock);
+        local_irq_restore(flags);
+        preempt_enable();
+}
+
+static inline void __read_unlock_irq(rwlock_t *lock)
+{
+        rwlock_release(&lock->dep_map, 1, _RET_IP_);
+        _raw_read_unlock(lock);
+        local_irq_enable();
+        preempt_enable();
+}
+
+static inline void __read_unlock_bh(rwlock_t *lock)
+{
+        rwlock_release(&lock->dep_map, 1, _RET_IP_);
+        _raw_read_unlock(lock);
+        preempt_enable_no_resched();
+        local_bh_enable_ip((unsigned long)__builtin_return_address(0));
+}
+
+static inline void __write_unlock_irqrestore(rwlock_t *lock,
+                                             unsigned long flags)
+{
+        rwlock_release(&lock->dep_map, 1, _RET_IP_);
+        _raw_write_unlock(lock);
+        local_irq_restore(flags);
+        preempt_enable();
+}
+
+static inline void __write_unlock_irq(rwlock_t *lock)
+{
+        rwlock_release(&lock->dep_map, 1, _RET_IP_);
+        _raw_write_unlock(lock);
+        local_irq_enable();
+        preempt_enable();
+}
+
+static inline void __write_unlock_bh(rwlock_t *lock)
+{
+        rwlock_release(&lock->dep_map, 1, _RET_IP_);
+        _raw_write_unlock(lock);
+        preempt_enable_no_resched();
+        local_bh_enable_ip((unsigned long)__builtin_return_address(0));
+}
+
+static inline int __spin_trylock_bh(spinlock_t *lock)
+{
+        local_bh_disable();
+        preempt_disable();
+        if (_raw_spin_trylock(lock)) {
+                spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+                return 1;
+        }
+        preempt_enable_no_resched();
+        local_bh_enable_ip((unsigned long)__builtin_return_address(0));
+        return 0;
+}
+
 #endif /* __LINUX_SPINLOCK_API_SMP_H */
diff --git a/kernel/spinlock.c b/kernel/spinlock.c
index 7932653c4ebd..2c000f5c070b 100644
--- a/kernel/spinlock.c
+++ b/kernel/spinlock.c
@@ -23,40 +23,19 @@
 
 int __lockfunc _spin_trylock(spinlock_t *lock)
 {
-        preempt_disable();
-        if (_raw_spin_trylock(lock)) {
-                spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
-                return 1;
-        }
-        
-        preempt_enable();
-        return 0;
+        return __spin_trylock(lock);
 }
 EXPORT_SYMBOL(_spin_trylock);
 
 int __lockfunc _read_trylock(rwlock_t *lock)
 {
-        preempt_disable();
-        if (_raw_read_trylock(lock)) {
-                rwlock_acquire_read(&lock->dep_map, 0, 1, _RET_IP_);
-                return 1;
-        }
-
-        preempt_enable();
-        return 0;
+        return __read_trylock(lock);
 }
 EXPORT_SYMBOL(_read_trylock);
 
 int __lockfunc _write_trylock(rwlock_t *lock)
 {
-        preempt_disable();
-        if (_raw_write_trylock(lock)) {
-                rwlock_acquire(&lock->dep_map, 0, 1, _RET_IP_);
-                return 1;
-        }
-
-        preempt_enable();
-        return 0;
+        return __write_trylock(lock);
 }
 EXPORT_SYMBOL(_write_trylock);
 
@@ -69,129 +48,74 @@ EXPORT_SYMBOL(_write_trylock);
 
 void __lockfunc _read_lock(rwlock_t *lock)
 {
-        preempt_disable();
-        rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
-        LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
+        __read_lock(lock);
 }
 EXPORT_SYMBOL(_read_lock);
 
 unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
 {
-        unsigned long flags;
-
-        local_irq_save(flags);
-        preempt_disable();
-        spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
-        /*
-         * On lockdep we dont want the hand-coded irq-enable of
-         * _raw_spin_lock_flags() code, because lockdep assumes
-         * that interrupts are not re-enabled during lock-acquire:
-         */
-#ifdef CONFIG_LOCKDEP
-        LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
-#else
-        _raw_spin_lock_flags(lock, &flags);
-#endif
-        return flags;
+        return __spin_lock_irqsave(lock);
 }
 EXPORT_SYMBOL(_spin_lock_irqsave);
 
 void __lockfunc _spin_lock_irq(spinlock_t *lock)
 {
-        local_irq_disable();
-        preempt_disable();
-        spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
-        LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
+        __spin_lock_irq(lock);
 }
 EXPORT_SYMBOL(_spin_lock_irq);
 
 void __lockfunc _spin_lock_bh(spinlock_t *lock)
 {
-        local_bh_disable();
-        preempt_disable();
-        spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
-        LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
+        __spin_lock_bh(lock);
 }
 EXPORT_SYMBOL(_spin_lock_bh);
 
 unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)
 {
-        unsigned long flags;
-
-        local_irq_save(flags);
-        preempt_disable();
-        rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
-        LOCK_CONTENDED_FLAGS(lock, _raw_read_trylock, _raw_read_lock,
-                             _raw_read_lock_flags, &flags);
-        return flags;
+        return __read_lock_irqsave(lock);
 }
 EXPORT_SYMBOL(_read_lock_irqsave);
 
 void __lockfunc _read_lock_irq(rwlock_t *lock)
 {
-        local_irq_disable();
-        preempt_disable();
-        rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
-        LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
+        __read_lock_irq(lock);
 }
 EXPORT_SYMBOL(_read_lock_irq);
 
 void __lockfunc _read_lock_bh(rwlock_t *lock)
 {
-        local_bh_disable();
-        preempt_disable();
-        rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
-        LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
+        __read_lock_bh(lock);
 }
 EXPORT_SYMBOL(_read_lock_bh);
 
 unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock)
 {
-        unsigned long flags;
-
-        local_irq_save(flags);
-        preempt_disable();
-        rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
-        LOCK_CONTENDED_FLAGS(lock, _raw_write_trylock, _raw_write_lock,
-                             _raw_write_lock_flags, &flags);
-        return flags;
+        return __write_lock_irqsave(lock);
 }
 EXPORT_SYMBOL(_write_lock_irqsave);
 
 void __lockfunc _write_lock_irq(rwlock_t *lock)
 {
-        local_irq_disable();
-        preempt_disable();
-        rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
-        LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
+        __write_lock_irq(lock);
 }
 EXPORT_SYMBOL(_write_lock_irq);
 
 void __lockfunc _write_lock_bh(rwlock_t *lock)
 {
-        local_bh_disable();
-        preempt_disable();
-        rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
-        LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
+        __write_lock_bh(lock);
 }
 EXPORT_SYMBOL(_write_lock_bh);
 
 void __lockfunc _spin_lock(spinlock_t *lock)
 {
-        preempt_disable();
-        spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
-        LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
+        __spin_lock(lock);
 }
-
 EXPORT_SYMBOL(_spin_lock);
 
 void __lockfunc _write_lock(rwlock_t *lock)
 {
-        preempt_disable();
-        rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
-        LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
+        __write_lock(lock);
 }
-
 EXPORT_SYMBOL(_write_lock);
 
 #else /* CONFIG_PREEMPT: */
@@ -320,121 +244,79 @@ EXPORT_SYMBOL(_spin_lock_nest_lock);
 
 void __lockfunc _spin_unlock(spinlock_t *lock)
 {
-        spin_release(&lock->dep_map, 1, _RET_IP_);
-        _raw_spin_unlock(lock);
-        preempt_enable();
+        __spin_unlock(lock);
 }
 EXPORT_SYMBOL(_spin_unlock);
 
 void __lockfunc _write_unlock(rwlock_t *lock)
 {
-        rwlock_release(&lock->dep_map, 1, _RET_IP_);
-        _raw_write_unlock(lock);
-        preempt_enable();
+        __write_unlock(lock);
 }
 EXPORT_SYMBOL(_write_unlock);
 
 void __lockfunc _read_unlock(rwlock_t *lock)
 {
-        rwlock_release(&lock->dep_map, 1, _RET_IP_);
-        _raw_read_unlock(lock);
-        preempt_enable();
+        __read_unlock(lock);
 }
 EXPORT_SYMBOL(_read_unlock);
 
 void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
 {
-        spin_release(&lock->dep_map, 1, _RET_IP_);
-        _raw_spin_unlock(lock);
-        local_irq_restore(flags);
-        preempt_enable();
+        __spin_unlock_irqrestore(lock, flags);
 }
 EXPORT_SYMBOL(_spin_unlock_irqrestore);
 
 void __lockfunc _spin_unlock_irq(spinlock_t *lock)
 {
-        spin_release(&lock->dep_map, 1, _RET_IP_);
-        _raw_spin_unlock(lock);
-        local_irq_enable();
-        preempt_enable();
+        __spin_unlock_irq(lock);
 }
 EXPORT_SYMBOL(_spin_unlock_irq);
 
 void __lockfunc _spin_unlock_bh(spinlock_t *lock)
 {
-        spin_release(&lock->dep_map, 1, _RET_IP_);
-        _raw_spin_unlock(lock);
-        preempt_enable_no_resched();
-        local_bh_enable_ip((unsigned long)__builtin_return_address(0));
+        __spin_unlock_bh(lock);
 }
 EXPORT_SYMBOL(_spin_unlock_bh);
 
 void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
 {
-        rwlock_release(&lock->dep_map, 1, _RET_IP_);
-        _raw_read_unlock(lock);
-        local_irq_restore(flags);
-        preempt_enable();
+        __read_unlock_irqrestore(lock, flags);
 }
 EXPORT_SYMBOL(_read_unlock_irqrestore);
 
 void __lockfunc _read_unlock_irq(rwlock_t *lock)
 {
-        rwlock_release(&lock->dep_map, 1, _RET_IP_);
-        _raw_read_unlock(lock);
-        local_irq_enable();
-        preempt_enable();
+        __read_unlock_irq(lock);
 }
 EXPORT_SYMBOL(_read_unlock_irq);
 
 void __lockfunc _read_unlock_bh(rwlock_t *lock)
 {
-        rwlock_release(&lock->dep_map, 1, _RET_IP_);
-        _raw_read_unlock(lock);
-        preempt_enable_no_resched();
-        local_bh_enable_ip((unsigned long)__builtin_return_address(0));
+        __read_unlock_bh(lock);
 }
 EXPORT_SYMBOL(_read_unlock_bh);
 
 void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
 {
-        rwlock_release(&lock->dep_map, 1, _RET_IP_);
-        _raw_write_unlock(lock);
-        local_irq_restore(flags);
-        preempt_enable();
+        __write_unlock_irqrestore(lock, flags);
 }
 EXPORT_SYMBOL(_write_unlock_irqrestore);
 
 void __lockfunc _write_unlock_irq(rwlock_t *lock)
 {
-        rwlock_release(&lock->dep_map, 1, _RET_IP_);
-        _raw_write_unlock(lock);
-        local_irq_enable();
-        preempt_enable();
+        __write_unlock_irq(lock);
 }
 EXPORT_SYMBOL(_write_unlock_irq);
 
 void __lockfunc _write_unlock_bh(rwlock_t *lock)
 {
-        rwlock_release(&lock->dep_map, 1, _RET_IP_);
-        _raw_write_unlock(lock);
-        preempt_enable_no_resched();
-        local_bh_enable_ip((unsigned long)__builtin_return_address(0));
+        __write_unlock_bh(lock);
 }
 EXPORT_SYMBOL(_write_unlock_bh);
 
 int __lockfunc _spin_trylock_bh(spinlock_t *lock)
 {
-        local_bh_disable();
-        preempt_disable();
-        if (_raw_spin_trylock(lock)) {
-                spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
-                return 1;
-        }
-
-        preempt_enable_no_resched();
-        local_bh_enable_ip((unsigned long)__builtin_return_address(0));
-        return 0;
+        return __spin_trylock_bh(lock);
 }
 EXPORT_SYMBOL(_spin_trylock_bh);