#define __LINUX_SPINLOCK_H
/*
- * include/linux/spinlock.h - generic locking declarations
+ * include/linux/spinlock.h - generic spinlock/rwlock declarations
+ *
+ * here's the role of the various spinlock/rwlock related include files:
+ *
+ * on SMP builds:
+ *
+ * asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
+ * initializers
+ *
+ * linux/spinlock_types.h:
+ * defines the generic type and initializers
+ *
+ * asm/spinlock.h: contains the __raw_spin_*()/etc. lowlevel
+ * implementations, mostly inline assembly code
+ *
+ * (also included on UP-debug builds:)
+ *
+ * linux/spinlock_api_smp.h:
+ * contains the prototypes for the _spin_*() APIs.
+ *
+ * linux/spinlock.h: builds the final spin_*() APIs.
+ *
+ * on UP builds:
+ *
+ * linux/spinlock_type_up.h:
+ * contains the generic, simplified UP spinlock type.
+ * (which is an empty structure on non-debug builds)
+ *
+ * linux/spinlock_types.h:
+ * defines the generic type and initializers
+ *
+ * linux/spinlock_up.h:
+ * contains the __raw_spin_*()/etc. version of UP
+ * builds. (which are NOPs on non-debug, non-preempt
+ * builds)
+ *
+ * (included on UP-non-debug builds:)
+ *
+ * linux/spinlock_api_up.h:
+ * builds the _spin_*() APIs.
+ *
+ * linux/spinlock.h: builds the final spin_*() APIs.
*/
-#include <linux/config.h>
#include <linux/preempt.h>
#include <linux/linkage.h>
#include <linux/compiler.h>
#include <linux/thread_info.h>
#include <linux/kernel.h>
#include <linux/stringify.h>
+#include <linux/bottom_half.h>
-#include <asm/processor.h> /* for cpu relax */
#include <asm/system.h>
/*
* Must define these before including other files, inline functions need them
*/
-#define LOCK_SECTION_NAME \
- ".text.lock." __stringify(KBUILD_BASENAME)
+#define LOCK_SECTION_NAME ".text.lock."KBUILD_BASENAME
+
+#define LOCK_SECTION_START(extra) \
+ ".subsection 1\n\t" \
+ extra \
+ ".ifndef " LOCK_SECTION_NAME "\n\t" \
+ LOCK_SECTION_NAME ":\n\t" \
+ ".endif\n"
-#define LOCK_SECTION_START(extra) \
- ".subsection 1\n\t" \
- extra \
- ".ifndef " LOCK_SECTION_NAME "\n\t" \
- LOCK_SECTION_NAME ":\n\t" \
- ".endif\n\t"
+#define LOCK_SECTION_END \
+ ".previous\n\t"
-#define LOCK_SECTION_END \
- ".previous\n\t"
+#define __lockfunc fastcall __attribute__((section(".spinlock.text")))
/*
- * If CONFIG_SMP is set, pull in the _raw_* definitions
+ * Pull the raw_spinlock_t and raw_rwlock_t definitions:
*/
-#ifdef CONFIG_SMP
-#include <asm/spinlock.h>
+#include <linux/spinlock_types.h>
-#else
+extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
-#if !defined(CONFIG_PREEMPT) && !defined(CONFIG_DEBUG_SPINLOCK)
-# define atomic_dec_and_lock(atomic,lock) atomic_dec_and_test(atomic)
-# define ATOMIC_DEC_AND_LOCK
+/*
+ * Pull the __raw*() functions/declarations (UP-nondebug doesnt need them):
+ */
+#ifdef CONFIG_SMP
+# include <asm/spinlock.h>
+#else
+# include <linux/spinlock_up.h>
#endif
#ifdef CONFIG_DEBUG_SPINLOCK
-
-#define SPINLOCK_MAGIC 0x1D244B3C
-typedef struct {
- unsigned long magic;
- volatile unsigned long lock;
- volatile unsigned int babble;
- const char *module;
- char *owner;
- int oline;
-} spinlock_t;
-#define SPIN_LOCK_UNLOCKED (spinlock_t) { SPINLOCK_MAGIC, 0, 10, __FILE__ , NULL, 0}
-
-#define spin_lock_init(x) \
- do { \
- (x)->magic = SPINLOCK_MAGIC; \
- (x)->lock = 0; \
- (x)->babble = 5; \
- (x)->module = __FILE__; \
- (x)->owner = NULL; \
- (x)->oline = 0; \
- } while (0)
-
-#define CHECK_LOCK(x) \
- do { \
- if ((x)->magic != SPINLOCK_MAGIC) { \
- printk(KERN_ERR "%s:%d: spin_is_locked on uninitialized spinlock %p.\n", \
- __FILE__, __LINE__, (x)); \
- } \
- } while(0)
-
-#define _raw_spin_lock(x) \
- do { \
- CHECK_LOCK(x); \
- if ((x)->lock&&(x)->babble) { \
- (x)->babble--; \
- printk("%s:%d: spin_lock(%s:%p) already locked by %s/%d\n", \
- __FILE__,__LINE__, (x)->module, \
- (x), (x)->owner, (x)->oline); \
- } \
- (x)->lock = 1; \
- (x)->owner = __FILE__; \
- (x)->oline = __LINE__; \
- } while (0)
-
-/* without debugging, spin_is_locked on UP always says
- * FALSE. --> printk if already locked. */
-#define spin_is_locked(x) \
- ({ \
- CHECK_LOCK(x); \
- if ((x)->lock&&(x)->babble) { \
- (x)->babble--; \
- printk("%s:%d: spin_is_locked(%s:%p) already locked by %s/%d\n", \
- __FILE__,__LINE__, (x)->module, \
- (x), (x)->owner, (x)->oline); \
- } \
- 0; \
- })
-
-/* without debugging, spin_trylock on UP always says
- * TRUE. --> printk if already locked. */
-#define _raw_spin_trylock(x) \
- ({ \
- CHECK_LOCK(x); \
- if ((x)->lock&&(x)->babble) { \
- (x)->babble--; \
- printk("%s:%d: spin_trylock(%s:%p) already locked by %s/%d\n", \
- __FILE__,__LINE__, (x)->module, \
- (x), (x)->owner, (x)->oline); \
- } \
- (x)->lock = 1; \
- (x)->owner = __FILE__; \
- (x)->oline = __LINE__; \
- 1; \
- })
-
-#define spin_unlock_wait(x) \
- do { \
- CHECK_LOCK(x); \
- if ((x)->lock&&(x)->babble) { \
- (x)->babble--; \
- printk("%s:%d: spin_unlock_wait(%s:%p) owned by %s/%d\n", \
- __FILE__,__LINE__, (x)->module, (x), \
- (x)->owner, (x)->oline); \
- }\
- } while (0)
-
-#define _raw_spin_unlock(x) \
- do { \
- CHECK_LOCK(x); \
- if (!(x)->lock&&(x)->babble) { \
- (x)->babble--; \
- printk("%s:%d: spin_unlock(%s:%p) not locked\n", \
- __FILE__,__LINE__, (x)->module, (x));\
- } \
- (x)->lock = 0; \
- } while (0)
+ extern void __spin_lock_init(spinlock_t *lock, const char *name,
+ struct lock_class_key *key);
+# define spin_lock_init(lock) \
+do { \
+ static struct lock_class_key __key; \
+ \
+ __spin_lock_init((lock), #lock, &__key); \
+} while (0)
+
#else
-/*
- * gcc versions before ~2.95 have a nasty bug with empty initializers.
- */
-#if (__GNUC__ > 2)
- typedef struct { } spinlock_t;
- #define SPIN_LOCK_UNLOCKED (spinlock_t) { }
+# define spin_lock_init(lock) \
+ do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0)
+#endif
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+ extern void __rwlock_init(rwlock_t *lock, const char *name,
+ struct lock_class_key *key);
+# define rwlock_init(lock) \
+do { \
+ static struct lock_class_key __key; \
+ \
+ __rwlock_init((lock), #lock, &__key); \
+} while (0)
#else
- typedef struct { int gcc_is_buggy; } spinlock_t;
- #define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 }
+# define rwlock_init(lock) \
+ do { *(lock) = RW_LOCK_UNLOCKED; } while (0)
#endif
+#define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock)
+
+/**
+ * spin_unlock_wait - wait until the spinlock gets unlocked
+ * @lock: the spinlock in question.
+ */
+#define spin_unlock_wait(lock) __raw_spin_unlock_wait(&(lock)->raw_lock)
+
/*
- * If CONFIG_SMP is unset, declare the _raw_* definitions as nops
+ * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
*/
-#define spin_lock_init(lock) do { (void)(lock); } while(0)
-#define _raw_spin_lock(lock) do { (void)(lock); } while(0)
-#define spin_is_locked(lock) ((void)(lock), 0)
-#define _raw_spin_trylock(lock) ((void)(lock), 1)
-#define spin_unlock_wait(lock) do { (void)(lock); } while(0)
-#define _raw_spin_unlock(lock) do { (void)(lock); } while(0)
-#endif /* CONFIG_DEBUG_SPINLOCK */
-
-/* RW spinlocks: No debug version */
-
-#if (__GNUC__ > 2)
- typedef struct { } rwlock_t;
- #define RW_LOCK_UNLOCKED (rwlock_t) { }
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+# include <linux/spinlock_api_smp.h>
#else
- typedef struct { int gcc_is_buggy; } rwlock_t;
- #define RW_LOCK_UNLOCKED (rwlock_t) { 0 }
+# include <linux/spinlock_api_up.h>
#endif
-#define rwlock_init(lock) do { (void)(lock); } while(0)
-#define _raw_read_lock(lock) do { (void)(lock); } while(0)
-#define _raw_read_unlock(lock) do { (void)(lock); } while(0)
-#define _raw_write_lock(lock) do { (void)(lock); } while(0)
-#define _raw_write_unlock(lock) do { (void)(lock); } while(0)
-#define _raw_write_trylock(lock) ({ (void)(lock); (1); })
+#ifdef CONFIG_DEBUG_SPINLOCK
+ extern void _raw_spin_lock(spinlock_t *lock);
+#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
+ extern int _raw_spin_trylock(spinlock_t *lock);
+ extern void _raw_spin_unlock(spinlock_t *lock);
+ extern void _raw_read_lock(rwlock_t *lock);
+ extern int _raw_read_trylock(rwlock_t *lock);
+ extern void _raw_read_unlock(rwlock_t *lock);
+ extern void _raw_write_lock(rwlock_t *lock);
+ extern int _raw_write_trylock(rwlock_t *lock);
+ extern void _raw_write_unlock(rwlock_t *lock);
+#else
+# define _raw_spin_lock(lock) __raw_spin_lock(&(lock)->raw_lock)
+# define _raw_spin_lock_flags(lock, flags) \
+ __raw_spin_lock_flags(&(lock)->raw_lock, *(flags))
+# define _raw_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock)
+# define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
+# define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock)
+# define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock)
+# define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock)
+# define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock)
+# define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock)
+# define _raw_write_unlock(rwlock) __raw_write_unlock(&(rwlock)->raw_lock)
+#endif
-#endif /* !SMP */
+#define read_can_lock(rwlock) __raw_read_can_lock(&(rwlock)->raw_lock)
+#define write_can_lock(rwlock) __raw_write_can_lock(&(rwlock)->raw_lock)
/*
* Define the various spin_lock and rw_lock methods. Note we define these
* regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
* methods are defined as nops in the case they are not required.
*/
-#define spin_trylock(lock) ({preempt_disable(); _raw_spin_trylock(lock) ? \
- 1 : ({preempt_enable(); 0;});})
-
-#define write_trylock(lock) ({preempt_disable();_raw_write_trylock(lock) ? \
- 1 : ({preempt_enable(); 0;});})
-
-/* Where's read_trylock? */
+#define spin_trylock(lock) __cond_lock(lock, _spin_trylock(lock))
+#define read_trylock(lock) __cond_lock(lock, _read_trylock(lock))
+#define write_trylock(lock) __cond_lock(lock, _write_trylock(lock))
-#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT)
-void __preempt_spin_lock(spinlock_t *lock);
-void __preempt_write_lock(rwlock_t *lock);
-
-#define spin_lock(lock) \
-do { \
- preempt_disable(); \
- if (unlikely(!_raw_spin_trylock(lock))) \
- __preempt_spin_lock(lock); \
-} while (0)
-
-#define write_lock(lock) \
-do { \
- preempt_disable(); \
- if (unlikely(!_raw_write_trylock(lock))) \
- __preempt_write_lock(lock); \
-} while (0)
+#define spin_lock(lock) _spin_lock(lock)
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass)
#else
-#define spin_lock(lock) \
-do { \
- preempt_disable(); \
- _raw_spin_lock(lock); \
-} while(0)
-
-#define write_lock(lock) \
-do { \
- preempt_disable(); \
- _raw_write_lock(lock); \
-} while(0)
+# define spin_lock_nested(lock, subclass) _spin_lock(lock)
#endif
-#define read_lock(lock) \
-do { \
- preempt_disable(); \
- _raw_read_lock(lock); \
-} while(0)
-
-#define spin_unlock(lock) \
-do { \
- _raw_spin_unlock(lock); \
- preempt_enable(); \
-} while (0)
+#define write_lock(lock) _write_lock(lock)
+#define read_lock(lock) _read_lock(lock)
-#define write_unlock(lock) \
-do { \
- _raw_write_unlock(lock); \
- preempt_enable(); \
-} while(0)
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
-#define read_unlock(lock) \
-do { \
- _raw_read_unlock(lock); \
- preempt_enable(); \
-} while(0)
+#define spin_lock_irqsave(lock, flags) flags = _spin_lock_irqsave(lock)
+#define read_lock_irqsave(lock, flags) flags = _read_lock_irqsave(lock)
+#define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock)
-#define spin_lock_irqsave(lock, flags) \
-do { \
- local_irq_save(flags); \
- preempt_disable(); \
- _raw_spin_lock(lock); \
-} while (0)
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+#define spin_lock_irqsave_nested(lock, flags, subclass) \
+ flags = _spin_lock_irqsave_nested(lock, subclass)
+#else
+#define spin_lock_irqsave_nested(lock, flags, subclass) \
+ flags = _spin_lock_irqsave(lock)
+#endif
-#define spin_lock_irq(lock) \
-do { \
- local_irq_disable(); \
- preempt_disable(); \
- _raw_spin_lock(lock); \
-} while (0)
+#else
-#define spin_lock_bh(lock) \
-do { \
- local_bh_disable(); \
- preempt_disable(); \
- _raw_spin_lock(lock); \
-} while (0)
+#define spin_lock_irqsave(lock, flags) _spin_lock_irqsave(lock, flags)
+#define read_lock_irqsave(lock, flags) _read_lock_irqsave(lock, flags)
+#define write_lock_irqsave(lock, flags) _write_lock_irqsave(lock, flags)
+#define spin_lock_irqsave_nested(lock, flags, subclass) \
+ spin_lock_irqsave(lock, flags)
-#define read_lock_irqsave(lock, flags) \
-do { \
- local_irq_save(flags); \
- preempt_disable(); \
- _raw_read_lock(lock); \
-} while (0)
-
-#define read_lock_irq(lock) \
-do { \
- local_irq_disable(); \
- preempt_disable(); \
- _raw_read_lock(lock); \
-} while (0)
+#endif
-#define read_lock_bh(lock) \
-do { \
- local_bh_disable(); \
- preempt_disable(); \
- _raw_read_lock(lock); \
-} while (0)
+#define spin_lock_irq(lock) _spin_lock_irq(lock)
+#define spin_lock_bh(lock) _spin_lock_bh(lock)
-#define write_lock_irqsave(lock, flags) \
-do { \
- local_irq_save(flags); \
- preempt_disable(); \
- _raw_write_lock(lock); \
-} while (0)
+#define read_lock_irq(lock) _read_lock_irq(lock)
+#define read_lock_bh(lock) _read_lock_bh(lock)
-#define write_lock_irq(lock) \
-do { \
- local_irq_disable(); \
- preempt_disable(); \
- _raw_write_lock(lock); \
-} while (0)
+#define write_lock_irq(lock) _write_lock_irq(lock)
+#define write_lock_bh(lock) _write_lock_bh(lock)
-#define write_lock_bh(lock) \
-do { \
- local_bh_disable(); \
- preempt_disable(); \
- _raw_write_lock(lock); \
-} while (0)
+/*
+ * We inline the unlock functions in the nondebug case:
+ */
+#if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || \
+ !defined(CONFIG_SMP)
+# define spin_unlock(lock) _spin_unlock(lock)
+# define read_unlock(lock) _read_unlock(lock)
+# define write_unlock(lock) _write_unlock(lock)
+# define spin_unlock_irq(lock) _spin_unlock_irq(lock)
+# define read_unlock_irq(lock) _read_unlock_irq(lock)
+# define write_unlock_irq(lock) _write_unlock_irq(lock)
+#else
+# define spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
+# define read_unlock(lock) __raw_read_unlock(&(lock)->raw_lock)
+# define write_unlock(lock) __raw_write_unlock(&(lock)->raw_lock)
+# define spin_unlock_irq(lock) \
+ do { __raw_spin_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
+# define read_unlock_irq(lock) \
+ do { __raw_read_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
+# define write_unlock_irq(lock) \
+ do { __raw_write_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
+#endif
#define spin_unlock_irqrestore(lock, flags) \
-do { \
- _raw_spin_unlock(lock); \
- local_irq_restore(flags); \
- preempt_enable(); \
-} while (0)
-
-#define _raw_spin_unlock_irqrestore(lock, flags) \
-do { \
- _raw_spin_unlock(lock); \
- local_irq_restore(flags); \
-} while (0)
-
-#define spin_unlock_irq(lock) \
-do { \
- _raw_spin_unlock(lock); \
- local_irq_enable(); \
- preempt_enable(); \
-} while (0)
-
-#define spin_unlock_bh(lock) \
-do { \
- _raw_spin_unlock(lock); \
- preempt_enable(); \
- local_bh_enable(); \
-} while (0)
+ _spin_unlock_irqrestore(lock, flags)
+#define spin_unlock_bh(lock) _spin_unlock_bh(lock)
#define read_unlock_irqrestore(lock, flags) \
-do { \
- _raw_read_unlock(lock); \
- local_irq_restore(flags); \
- preempt_enable(); \
-} while (0)
-
-#define read_unlock_irq(lock) \
-do { \
- _raw_read_unlock(lock); \
- local_irq_enable(); \
- preempt_enable(); \
-} while (0)
-
-#define read_unlock_bh(lock) \
-do { \
- _raw_read_unlock(lock); \
- preempt_enable(); \
- local_bh_enable(); \
-} while (0)
+ _read_unlock_irqrestore(lock, flags)
+#define read_unlock_bh(lock) _read_unlock_bh(lock)
#define write_unlock_irqrestore(lock, flags) \
-do { \
- _raw_write_unlock(lock); \
- local_irq_restore(flags); \
- preempt_enable(); \
-} while (0)
-
-#define write_unlock_irq(lock) \
-do { \
- _raw_write_unlock(lock); \
- local_irq_enable(); \
- preempt_enable(); \
-} while (0)
+ _write_unlock_irqrestore(lock, flags)
+#define write_unlock_bh(lock) _write_unlock_bh(lock)
-#define write_unlock_bh(lock) \
-do { \
- _raw_write_unlock(lock); \
- preempt_enable(); \
- local_bh_enable(); \
-} while (0)
+#define spin_trylock_bh(lock) __cond_lock(lock, _spin_trylock_bh(lock))
-#define spin_trylock_bh(lock) ({ local_bh_disable(); preempt_disable(); \
- _raw_spin_trylock(lock) ? 1 : \
- ({preempt_enable(); local_bh_enable(); 0;});})
-
-/* "lock on reference count zero" */
-#ifndef ATOMIC_DEC_AND_LOCK
-#include <asm/atomic.h>
-extern int atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
-#endif
+#define spin_trylock_irq(lock) \
+({ \
+ local_irq_disable(); \
+ spin_trylock(lock) ? \
+ 1 : ({ local_irq_enable(); 0; }); \
+})
-/*
- * bit-based spin_lock()
- *
- * Don't use this unless you really need to: spin_lock() and spin_unlock()
- * are significantly faster.
- */
-static inline void bit_spin_lock(int bitnum, unsigned long *addr)
-{
- /*
- * Assuming the lock is uncontended, this never enters
- * the body of the outer loop. If it is contended, then
- * within the inner loop a non-atomic test is used to
- * busywait with less bus contention for a good time to
- * attempt to acquire the lock bit.
- */
- preempt_disable();
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
- while (test_and_set_bit(bitnum, addr)) {
- while (test_bit(bitnum, addr))
- cpu_relax();
- }
-#endif
-}
+#define spin_trylock_irqsave(lock, flags) \
+({ \
+ local_irq_save(flags); \
+ spin_trylock(lock) ? \
+ 1 : ({ local_irq_restore(flags); 0; }); \
+})
/*
- * Return true if it was acquired
+ * Pull the atomic_t declaration:
+ * (asm-mips/atomic.h needs above definitions)
*/
-static inline int bit_spin_trylock(int bitnum, unsigned long *addr)
-{
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
- int ret;
-
- preempt_disable();
- ret = !test_and_set_bit(bitnum, addr);
- if (!ret)
- preempt_enable();
- return ret;
-#else
- preempt_disable();
- return 1;
-#endif
-}
-
-/*
- * bit-based spin_unlock()
+#include <asm/atomic.h>
+/**
+ * atomic_dec_and_lock - lock on reaching reference count zero
+ * @atomic: the atomic counter
+ * @lock: the spinlock in question
*/
-static inline void bit_spin_unlock(int bitnum, unsigned long *addr)
-{
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
- BUG_ON(!test_bit(bitnum, addr));
- smp_mb__before_clear_bit();
- clear_bit(bitnum, addr);
-#endif
- preempt_enable();
-}
+extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
+#define atomic_dec_and_lock(atomic, lock) \
+ __cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
-/*
- * Return true if the lock is held.
+/**
+ * spin_can_lock - would spin_trylock() succeed?
+ * @lock: the spinlock in question.
*/
-static inline int bit_spin_is_locked(int bitnum, unsigned long *addr)
-{
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
- return test_bit(bitnum, addr);
-#elif defined CONFIG_PREEMPT
- return preempt_count();
-#else
- return 1;
-#endif
-}
+#define spin_can_lock(lock) (!spin_is_locked(lock))
#endif /* __LINUX_SPINLOCK_H */
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