aboutsummaryrefslogtreecommitdiff
path: root/include/asm-sh/rwsem.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/asm-sh/rwsem.h')
-rw-r--r--include/asm-sh/rwsem.h188
1 files changed, 0 insertions, 188 deletions
diff --git a/include/asm-sh/rwsem.h b/include/asm-sh/rwsem.h
deleted file mode 100644
index 1987f3ea7f1..00000000000
--- a/include/asm-sh/rwsem.h
+++ /dev/null
@@ -1,188 +0,0 @@
-/*
- * include/asm-sh/rwsem.h: R/W semaphores for SH using the stuff
- * in lib/rwsem.c.
- */
-
-#ifndef _ASM_SH_RWSEM_H
-#define _ASM_SH_RWSEM_H
-
-#ifndef _LINUX_RWSEM_H
-#error "please don't include asm/rwsem.h directly, use linux/rwsem.h instead"
-#endif
-
-#ifdef __KERNEL__
-#include <linux/list.h>
-#include <linux/spinlock.h>
-#include <asm/atomic.h>
-#include <asm/system.h>
-
-/*
- * the semaphore definition
- */
-struct rw_semaphore {
- long count;
-#define RWSEM_UNLOCKED_VALUE 0x00000000
-#define RWSEM_ACTIVE_BIAS 0x00000001
-#define RWSEM_ACTIVE_MASK 0x0000ffff
-#define RWSEM_WAITING_BIAS (-0x00010000)
-#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
-#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
- 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_DEP_MAP_INIT(name) }
-
-#define DECLARE_RWSEM(name) \
- struct rw_semaphore name = __RWSEM_INITIALIZER(name)
-
-extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
-
-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)
-
-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);
-}
-
-/*
- * lock for reading
- */
-static inline void __down_read(struct rw_semaphore *sem)
-{
- if (atomic_inc_return((atomic_t *)(&sem->count)) > 0)
- smp_wmb();
- else
- rwsem_down_read_failed(sem);
-}
-
-static inline int __down_read_trylock(struct rw_semaphore *sem)
-{
- int tmp;
-
- while ((tmp = sem->count) >= 0) {
- if (tmp == cmpxchg(&sem->count, tmp,
- tmp + RWSEM_ACTIVE_READ_BIAS)) {
- smp_wmb();
- return 1;
- }
- }
- return 0;
-}
-
-/*
- * lock for writing
- */
-static inline void __down_write(struct rw_semaphore *sem)
-{
- int tmp;
-
- tmp = atomic_add_return(RWSEM_ACTIVE_WRITE_BIAS,
- (atomic_t *)(&sem->count));
- if (tmp == RWSEM_ACTIVE_WRITE_BIAS)
- smp_wmb();
- else
- rwsem_down_write_failed(sem);
-}
-
-static inline int __down_write_trylock(struct rw_semaphore *sem)
-{
- int tmp;
-
- tmp = cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE,
- RWSEM_ACTIVE_WRITE_BIAS);
- smp_wmb();
- return tmp == RWSEM_UNLOCKED_VALUE;
-}
-
-/*
- * unlock after reading
- */
-static inline void __up_read(struct rw_semaphore *sem)
-{
- int tmp;
-
- smp_wmb();
- tmp = atomic_dec_return((atomic_t *)(&sem->count));
- if (tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0)
- rwsem_wake(sem);
-}
-
-/*
- * unlock after writing
- */
-static inline void __up_write(struct rw_semaphore *sem)
-{
- smp_wmb();
- if (atomic_sub_return(RWSEM_ACTIVE_WRITE_BIAS,
- (atomic_t *)(&sem->count)) < 0)
- rwsem_wake(sem);
-}
-
-/*
- * implement atomic add functionality
- */
-static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem)
-{
- atomic_add(delta, (atomic_t *)(&sem->count));
-}
-
-/*
- * downgrade write lock to read lock
- */
-static inline void __downgrade_write(struct rw_semaphore *sem)
-{
- int tmp;
-
- smp_wmb();
- tmp = atomic_add_return(-RWSEM_WAITING_BIAS, (atomic_t *)(&sem->count));
- if (tmp < 0)
- rwsem_downgrade_wake(sem);
-}
-
-static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
-{
- __down_write(sem);
-}
-
-/*
- * implement exchange and add functionality
- */
-static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
-{
- smp_mb();
- return atomic_add_return(delta, (atomic_t *)(&sem->count));
-}
-
-static inline int rwsem_is_locked(struct rw_semaphore *sem)
-{
- return (sem->count != 0);
-}
-
-#endif /* __KERNEL__ */
-#endif /* _ASM_SH_RWSEM_H */