signed int count;
spinlock_t wait_lock;
struct list_head wait_list;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
};
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname }
+#else
+# define __RWSEM_DEP_MAP_INIT(lockname)
+#endif
+
#define __RWSEM_INITIALIZER(name) \
-{ RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) }
+{ RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) \
+ __RWSEM_DEP_MAP_INIT(name) }
#define DECLARE_RWSEM(name) \
struct rw_semaphore name = __RWSEM_INITIALIZER(name)
-static __inline__ void init_rwsem(struct rw_semaphore *sem)
-{
- sem->count = RWSEM_UNLOCKED_VALUE;
- spin_lock_init(&sem->wait_lock);
- INIT_LIST_HEAD(&sem->wait_list);
-}
+extern void __init_rwsem(struct rw_semaphore *sem, const char *name,
+ struct lock_class_key *key);
+
+#define init_rwsem(sem) \
+do { \
+ static struct lock_class_key __key; \
+ \
+ __init_rwsem((sem), #sem, &__key); \
+} while (0)
extern void __down_read(struct rw_semaphore *sem);
extern int __down_read_trylock(struct rw_semaphore *sem);
extern void __up_write(struct rw_semaphore *sem);
extern void __downgrade_write(struct rw_semaphore *sem);
-static __inline__ int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
+static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
{
- int tmp = delta;
-
- __asm__ __volatile__(
- "1:\tlduw [%2], %%g1\n\t"
- "add %%g1, %1, %%g7\n\t"
- "cas [%2], %%g1, %%g7\n\t"
- "cmp %%g1, %%g7\n\t"
- "membar #StoreLoad | #StoreStore\n\t"
- "bne,pn %%icc, 1b\n\t"
- " nop\n\t"
- "mov %%g7, %0\n\t"
- : "=&r" (tmp)
- : "0" (tmp), "r" (sem)
- : "g1", "g7", "memory", "cc");
-
- return tmp + delta;
+ __down_write(sem);
}
-#define rwsem_atomic_add rwsem_atomic_update
+static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
+{
+ return atomic_add_return(delta, (atomic_t *)(&sem->count));
+}
-static __inline__ __u16 rwsem_cmpxchgw(struct rw_semaphore *sem, __u16 __old, __u16 __new)
+static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem)
{
- u32 old = (sem->count & 0xffff0000) | (u32) __old;
- u32 new = (old & 0xffff0000) | (u32) __new;
- u32 prev;
-
-again:
- __asm__ __volatile__("cas [%2], %3, %0\n\t"
- "membar #StoreLoad | #StoreStore"
- : "=&r" (prev)
- : "0" (new), "r" (sem), "r" (old)
- : "memory");
-
- /* To give the same semantics as x86 cmpxchgw, keep trying
- * if only the upper 16-bits changed.
- */
- if (prev != old &&
- ((prev & 0xffff) == (old & 0xffff)))
- goto again;
-
- return prev & 0xffff;
+ atomic_add(delta, (atomic_t *)(&sem->count));
}
-static __inline__ signed long rwsem_cmpxchg(struct rw_semaphore *sem, signed long old, signed long new)
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
- return cmpxchg(&sem->count,old,new);
+ return (sem->count != 0);
}
#endif /* __KERNEL__ */