|
@@ -1,132 +0,0 @@
|
|
|
-#ifndef _ASM_POWERPC_RWSEM_H
|
|
|
-#define _ASM_POWERPC_RWSEM_H
|
|
|
-
|
|
|
-#ifndef _LINUX_RWSEM_H
|
|
|
-#error "Please don't include <asm/rwsem.h> directly, use <linux/rwsem.h> instead."
|
|
|
-#endif
|
|
|
-
|
|
|
-#ifdef __KERNEL__
|
|
|
-
|
|
|
-/*
|
|
|
- * R/W semaphores for PPC using the stuff in lib/rwsem.c.
|
|
|
- * Adapted largely from include/asm-i386/rwsem.h
|
|
|
- * by Paul Mackerras <paulus@samba.org>.
|
|
|
- */
|
|
|
-
|
|
|
-/*
|
|
|
- * the semaphore definition
|
|
|
- */
|
|
|
-#ifdef CONFIG_PPC64
|
|
|
-# define RWSEM_ACTIVE_MASK 0xffffffffL
|
|
|
-#else
|
|
|
-# define RWSEM_ACTIVE_MASK 0x0000ffffL
|
|
|
-#endif
|
|
|
-
|
|
|
-#define RWSEM_UNLOCKED_VALUE 0x00000000L
|
|
|
-#define RWSEM_ACTIVE_BIAS 0x00000001L
|
|
|
-#define RWSEM_WAITING_BIAS (-RWSEM_ACTIVE_MASK-1)
|
|
|
-#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
|
|
|
-#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
|
|
|
-
|
|
|
-/*
|
|
|
- * lock for reading
|
|
|
- */
|
|
|
-static inline void __down_read(struct rw_semaphore *sem)
|
|
|
-{
|
|
|
- if (unlikely(atomic_long_inc_return((atomic_long_t *)&sem->count) <= 0))
|
|
|
- rwsem_down_read_failed(sem);
|
|
|
-}
|
|
|
-
|
|
|
-static inline int __down_read_trylock(struct rw_semaphore *sem)
|
|
|
-{
|
|
|
- long tmp;
|
|
|
-
|
|
|
- while ((tmp = sem->count) >= 0) {
|
|
|
- if (tmp == cmpxchg(&sem->count, tmp,
|
|
|
- tmp + RWSEM_ACTIVE_READ_BIAS)) {
|
|
|
- return 1;
|
|
|
- }
|
|
|
- }
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
-/*
|
|
|
- * lock for writing
|
|
|
- */
|
|
|
-static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
|
|
|
-{
|
|
|
- long tmp;
|
|
|
-
|
|
|
- tmp = atomic_long_add_return(RWSEM_ACTIVE_WRITE_BIAS,
|
|
|
- (atomic_long_t *)&sem->count);
|
|
|
- if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS))
|
|
|
- rwsem_down_write_failed(sem);
|
|
|
-}
|
|
|
-
|
|
|
-static inline void __down_write(struct rw_semaphore *sem)
|
|
|
-{
|
|
|
- __down_write_nested(sem, 0);
|
|
|
-}
|
|
|
-
|
|
|
-static inline int __down_write_trylock(struct rw_semaphore *sem)
|
|
|
-{
|
|
|
- long tmp;
|
|
|
-
|
|
|
- tmp = cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE,
|
|
|
- RWSEM_ACTIVE_WRITE_BIAS);
|
|
|
- return tmp == RWSEM_UNLOCKED_VALUE;
|
|
|
-}
|
|
|
-
|
|
|
-/*
|
|
|
- * unlock after reading
|
|
|
- */
|
|
|
-static inline void __up_read(struct rw_semaphore *sem)
|
|
|
-{
|
|
|
- long tmp;
|
|
|
-
|
|
|
- tmp = atomic_long_dec_return((atomic_long_t *)&sem->count);
|
|
|
- if (unlikely(tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0))
|
|
|
- rwsem_wake(sem);
|
|
|
-}
|
|
|
-
|
|
|
-/*
|
|
|
- * unlock after writing
|
|
|
- */
|
|
|
-static inline void __up_write(struct rw_semaphore *sem)
|
|
|
-{
|
|
|
- if (unlikely(atomic_long_sub_return(RWSEM_ACTIVE_WRITE_BIAS,
|
|
|
- (atomic_long_t *)&sem->count) < 0))
|
|
|
- rwsem_wake(sem);
|
|
|
-}
|
|
|
-
|
|
|
-/*
|
|
|
- * implement atomic add functionality
|
|
|
- */
|
|
|
-static inline void rwsem_atomic_add(long delta, struct rw_semaphore *sem)
|
|
|
-{
|
|
|
- atomic_long_add(delta, (atomic_long_t *)&sem->count);
|
|
|
-}
|
|
|
-
|
|
|
-/*
|
|
|
- * downgrade write lock to read lock
|
|
|
- */
|
|
|
-static inline void __downgrade_write(struct rw_semaphore *sem)
|
|
|
-{
|
|
|
- long tmp;
|
|
|
-
|
|
|
- tmp = atomic_long_add_return(-RWSEM_WAITING_BIAS,
|
|
|
- (atomic_long_t *)&sem->count);
|
|
|
- if (tmp < 0)
|
|
|
- rwsem_downgrade_wake(sem);
|
|
|
-}
|
|
|
-
|
|
|
-/*
|
|
|
- * implement exchange and add functionality
|
|
|
- */
|
|
|
-static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem)
|
|
|
-{
|
|
|
- return atomic_long_add_return(delta, (atomic_long_t *)&sem->count);
|
|
|
-}
|
|
|
-
|
|
|
-#endif /* __KERNEL__ */
|
|
|
-#endif /* _ASM_POWERPC_RWSEM_H */
|