patch-2.4.4 linux/include/asm-parisc/semaphore.h
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- Lines: 178
- Date:
Tue Apr 17 17:19:31 2001
- Orig file:
v2.4.3/linux/include/asm-parisc/semaphore.h
- Orig date:
Tue Dec 5 12:29:39 2000
diff -u --recursive --new-file v2.4.3/linux/include/asm-parisc/semaphore.h linux/include/asm-parisc/semaphore.h
@@ -17,6 +17,7 @@
*/
#include <linux/spinlock.h>
+#include <linux/rwsem.h>
#include <asm/system.h>
#include <asm/atomic.h>
@@ -133,169 +134,6 @@
#endif
if (atomic_inc_return(&sem->count) <= 0)
__up(sem);
-}
-
-/* rw mutexes (should that be mutices? =) -- throw rw
- * spinlocks and semaphores together, and this is what we
- * end up with...
- *
- * The lock is initialized to BIAS. This way, a writer
- * subtracts BIAS ands gets 0 for the case of an uncontended
- * lock. Readers decrement by 1 and see a positive value
- * when uncontended, negative if there are writers waiting
- * (in which case it goes to sleep).
- *
- * The value 0x01000000 supports up to 128 processors and
- * lots of processes. BIAS must be chosen such that subl'ing
- * BIAS once per CPU will result in the long remaining
- * negative.
- *
- * In terms of fairness, this should result in the lock
- * flopping back and forth between readers and writers
- * under heavy use.
- *
- * -ben
- */
-struct rw_semaphore {
- atomic_t count;
- volatile unsigned char write_bias_granted;
- volatile unsigned char read_bias_granted;
- volatile unsigned char pad1;
- volatile unsigned char pad2;
- wait_queue_head_t wait;
- wait_queue_head_t write_bias_wait;
-#if WAITQUEUE_DEBUG
- long __magic;
- atomic_t readers;
- atomic_t writers;
-#endif
-};
-
-#if WAITQUEUE_DEBUG
-#define __RWSEM_DEBUG_INIT , ATOMIC_INIT(0), ATOMIC_INIT(0)
-#else
-#define __RWSEM_DEBUG_INIT /* */
-#endif
-
-#define RW_LOCK_BIAS 0x01000000
-
-#define __RWSEM_INITIALIZER(name,count) \
-{ ATOMIC_INIT(count), 0, 0, 0, 0, __WAIT_QUEUE_HEAD_INITIALIZER((name).wait), \
- __WAIT_QUEUE_HEAD_INITIALIZER((name).write_bias_wait) \
- __SEM_DEBUG_INIT(name) __RWSEM_DEBUG_INIT }
-
-#define __DECLARE_RWSEM_GENERIC(name,count) \
- struct rw_semaphore name = __RWSEM_INITIALIZER(name,count)
-
-#define DECLARE_RWSEM(name) __DECLARE_RWSEM_GENERIC(name,RW_LOCK_BIAS)
-#define DECLARE_RWSEM_READ_LOCKED(name) __DECLARE_RWSEM_GENERIC(name,RW_LOCK_BIAS-1)
-#define DECLARE_RWSEM_WRITE_LOCKED(name) __DECLARE_RWSEM_GENERIC(name,0)
-
-extern inline void init_rwsem(struct rw_semaphore *sem)
-{
- atomic_set(&sem->count, RW_LOCK_BIAS);
- sem->read_bias_granted = 0;
- sem->write_bias_granted = 0;
- init_waitqueue_head(&sem->wait);
- init_waitqueue_head(&sem->write_bias_wait);
-#if WAITQUEUE_DEBUG
- sem->__magic = (long)&sem->__magic;
- atomic_set(&sem->readers, 0);
- atomic_set(&sem->writers, 0);
-#endif
-}
-
-#ifdef FIXME_WILLY_FIXME_FOR_REAL_THIS_TIME
-extern struct rw_semaphore *__build_read_lock(struct rw_semaphore *sem, const char *what);
-extern struct rw_semaphore *__build_write_lock(struct rw_semaphore *sem, const char *what);
-#endif
-
-/* we use FASTCALL convention for the helpers */
-extern struct rw_semaphore *FASTCALL(__down_read_failed(struct rw_semaphore *sem));
-extern struct rw_semaphore *FASTCALL(__down_write_failed(struct rw_semaphore *sem));
-extern struct rw_semaphore *FASTCALL(__rwsem_wake(struct rw_semaphore *sem));
-
-extern inline void down_read(struct rw_semaphore *sem)
-{
-#if WAITQUEUE_DEBUG
- if (sem->__magic != (long)&sem->__magic)
- BUG();
-#endif
-#ifdef FIXME_WILLY_FIXME_FOR_REAL_THIS_TIME
- __build_read_lock(sem, "__down_read_failed");
-#endif
-#if WAITQUEUE_DEBUG
- if (sem->write_bias_granted)
- BUG();
- if (atomic_read(&sem->writers))
- BUG();
- atomic_inc(&sem->readers);
-#endif
-}
-
-extern inline void down_write(struct rw_semaphore *sem)
-{
-#if WAITQUEUE_DEBUG
- if (sem->__magic != (long)&sem->__magic)
- BUG();
-#endif
-#ifdef FIXME_WILLY_FIXME_FOR_REAL_THIS_TIME
- __build_write_lock(sem, "__down_write_failed");
-#endif
-#if WAITQUEUE_DEBUG
- if (atomic_read(&sem->writers))
- BUG();
- if (atomic_read(&sem->readers))
- BUG();
- if (sem->read_bias_granted)
- BUG();
- if (sem->write_bias_granted)
- BUG();
- atomic_inc(&sem->writers);
-#endif
-}
-
-/* When a reader does a release, the only significant
- * case is when there was a writer waiting, and we've
- * bumped the count to 0: we must wake the writer up.
- */
-extern inline void __up_read(struct rw_semaphore *sem)
-{
-}
-
-/* releasing the writer is easy -- just release it and
- * wake up any sleepers.
- */
-extern inline void __up_write(struct rw_semaphore *sem)
-{
-}
-
-extern inline void up_read(struct rw_semaphore *sem)
-{
-#if WAITQUEUE_DEBUG
- if (sem->write_bias_granted)
- BUG();
- if (atomic_read(&sem->writers))
- BUG();
- atomic_dec(&sem->readers);
-#endif
- __up_read(sem);
-}
-
-extern inline void up_write(struct rw_semaphore *sem)
-{
-#if WAITQUEUE_DEBUG
- if (sem->read_bias_granted)
- BUG();
- if (sem->write_bias_granted)
- BUG();
- if (atomic_read(&sem->readers))
- BUG();
- if (atomic_read(&sem->writers) != 1)
- BUG();
- atomic_dec(&sem->writers);
-#endif
- __up_write(sem);
}
#endif /* _ASM_PARISC_SEMAPHORE_H */
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