-typedef struct {
- spinlock_t lock;
- volatile int counter;
-#ifdef CONFIG_PREEMPT
- unsigned int break_lock;
-#endif
-} rwlock_t;
-
-#define RW_LOCK_UNLOCKED (rwlock_t) { {1}, 0 }
-
-#define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while (0)
-
-/**
- * read_can_lock - would read_trylock() succeed?
- * @lock: the rwlock in question.
- */
-#define read_can_lock(x) ((int)(x)->counter >= 0)
-
-/**
- * write_can_lock - would write_trylock() succeed?
- * @lock: the rwlock in question.
- */
-#define write_can_lock(x) ((x)->counter == 0)
-
-#define _raw_read_trylock(lock) generic_raw_read_trylock(lock)