Skip to content

Commit

Permalink
---
Browse files Browse the repository at this point in the history
yaml
---
r: 209935
b: refs/heads/master
c: 529b730
h: refs/heads/master
i:
  209933: ba7ff0c
  209931: 005bb5f
  209927: f917219
  209919: 9cf3cd8
v: v3
  • Loading branch information
Benjamin Herrenschmidt committed Aug 24, 2010
1 parent cba327c commit fd3dd6b
Show file tree
Hide file tree
Showing 2 changed files with 38 additions and 28 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: b1515af2911c4339ed34865a0594f4ad3392921a
refs/heads/master: 529b7307d804f649839b5b65b303442140266d26
64 changes: 37 additions & 27 deletions trunk/arch/powerpc/include/asm/rwsem.h
Original file line number Diff line number Diff line change
Expand Up @@ -21,15 +21,20 @@
/*
* the semaphore definition
*/
struct rw_semaphore {
/* XXX this should be able to be an atomic_t -- paulus */
signed int count;
#define RWSEM_UNLOCKED_VALUE 0x00000000
#define RWSEM_ACTIVE_BIAS 0x00000001
#define RWSEM_ACTIVE_MASK 0x0000ffff
#define RWSEM_WAITING_BIAS (-0x00010000)
#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)

struct rw_semaphore {
long count;
spinlock_t wait_lock;
struct list_head wait_list;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
Expand All @@ -43,9 +48,13 @@ struct rw_semaphore {
# define __RWSEM_DEP_MAP_INIT(lockname)
#endif

#define __RWSEM_INITIALIZER(name) \
{ RWSEM_UNLOCKED_VALUE, __SPIN_LOCK_UNLOCKED((name).wait_lock), \
LIST_HEAD_INIT((name).wait_list) __RWSEM_DEP_MAP_INIT(name) }
#define __RWSEM_INITIALIZER(name) \
{ \
RWSEM_UNLOCKED_VALUE, \
__SPIN_LOCK_UNLOCKED((name).wait_lock), \
LIST_HEAD_INIT((name).wait_list) \
__RWSEM_DEP_MAP_INIT(name) \
}

#define DECLARE_RWSEM(name) \
struct rw_semaphore name = __RWSEM_INITIALIZER(name)
Expand All @@ -70,13 +79,13 @@ extern void __init_rwsem(struct rw_semaphore *sem, const char *name,
*/
static inline void __down_read(struct rw_semaphore *sem)
{
if (unlikely(atomic_inc_return((atomic_t *)(&sem->count)) <= 0))
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)
{
int tmp;
long tmp;

while ((tmp = sem->count) >= 0) {
if (tmp == cmpxchg(&sem->count, tmp,
Expand All @@ -92,10 +101,10 @@ static inline int __down_read_trylock(struct rw_semaphore *sem)
*/
static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
{
int tmp;
long tmp;

tmp = atomic_add_return(RWSEM_ACTIVE_WRITE_BIAS,
(atomic_t *)(&sem->count));
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);
}
Expand All @@ -107,7 +116,7 @@ static inline void __down_write(struct rw_semaphore *sem)

static inline int __down_write_trylock(struct rw_semaphore *sem)
{
int tmp;
long tmp;

tmp = cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE,
RWSEM_ACTIVE_WRITE_BIAS);
Expand All @@ -119,9 +128,9 @@ static inline int __down_write_trylock(struct rw_semaphore *sem)
*/
static inline void __up_read(struct rw_semaphore *sem)
{
int tmp;
long tmp;

tmp = atomic_dec_return((atomic_t *)(&sem->count));
tmp = atomic_long_dec_return((atomic_long_t *)&sem->count);
if (unlikely(tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0))
rwsem_wake(sem);
}
Expand All @@ -131,42 +140,43 @@ static inline void __up_read(struct rw_semaphore *sem)
*/
static inline void __up_write(struct rw_semaphore *sem)
{
if (unlikely(atomic_sub_return(RWSEM_ACTIVE_WRITE_BIAS,
(atomic_t *)(&sem->count)) < 0))
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(int delta, struct rw_semaphore *sem)
static inline void rwsem_atomic_add(long delta, struct rw_semaphore *sem)
{
atomic_add(delta, (atomic_t *)(&sem->count));
atomic_long_add(delta, (atomic_long_t *)&sem->count);
}

/*
* downgrade write lock to read lock
*/
static inline void __downgrade_write(struct rw_semaphore *sem)
{
int tmp;
long tmp;

tmp = atomic_add_return(-RWSEM_WAITING_BIAS, (atomic_t *)(&sem->count));
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 int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem)
{
return atomic_add_return(delta, (atomic_t *)(&sem->count));
return atomic_long_add_return(delta, (atomic_long_t *)&sem->count);
}

static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
return (sem->count != 0);
return sem->count != 0;
}

#endif /* __KERNEL__ */
Expand Down

0 comments on commit fd3dd6b

Please sign in to comment.