patch-2.4.4 linux/include/asm-cris/semaphore.h

• Lines: 176
• Date: Tue Apr 17 17:19:30 2001
• Orig file: v2.4.3/linux/include/asm-cris/semaphore.h
• Orig date: Thu Feb 8 16:32:44 2001

diff -u --recursive --new-file v2.4.3/linux/include/asm-cris/semaphore.h linux/include/asm-cris/semaphore.h
@@ -9,6 +9,7 @@
 
 #include <linux/wait.h>
 #include <linux/spinlock.h>
+#include <linux/rwsem.h>
 
 #include <asm/system.h>
 #include <asm/atomic.h>
@@ -155,167 +156,6 @@
 	if(wakeup) {
 		__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).
- *
- * 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;
-	/* bit 0 means read bias granted;
-	   bit 1 means write bias granted.  */
-        unsigned granted;
-        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 __RWSEM_INITIALIZER(name,count) \
-{ ATOMIC_INIT(count), 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->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
-}
-
-/* The expensive part is outlined.  */
-extern void __down_read(struct rw_semaphore *sem, int count);
-extern void __down_write(struct rw_semaphore *sem, int count);
-extern void __rwsem_wake(struct rw_semaphore *sem, unsigned long readers);
-
-extern inline void down_read(struct rw_semaphore *sem)
-{
-        int count;
-
-#if WAITQUEUE_DEBUG
-        CHECK_MAGIC(sem->__magic);
-#endif
-
-        count = atomic_dec_return(&sem->count);
-        if (count < 0) {
-                __down_read(sem, count);
-        }
-        mb();
-
-#if WAITQUEUE_DEBUG
-        if (sem->granted & 2)
-                BUG();
-        if (atomic_read(&sem->writers))
-                BUG();
-        atomic_inc(&sem->readers);
-#endif
-}
-
-extern inline void down_write(struct rw_semaphore *sem)
-{
-        int count;
-
-#if WAITQUEUE_DEBUG
-        CHECK_MAGIC(sem->__magic);
-#endif
-
-        count = atomic_sub_return(RW_LOCK_BIAS, &sem->count);
-        if (count) {
-                __down_write(sem, count);
-        }
-        mb();
-
-#if WAITQUEUE_DEBUG
-        if (atomic_read(&sem->writers))
-                BUG();
-        if (atomic_read(&sem->readers))
-                BUG();
-        if (sem->granted & 3)
-                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)
-{
-#if WAITQUEUE_DEBUG
-        CHECK_MAGIC(sem->__magic);
-        if (sem->granted & 2)
-                BUG();
-        if (atomic_read(&sem->writers))
-                BUG();
-        atomic_dec(&sem->readers);
-#endif
-
-        mb();
-        if (atomic_inc_return(&sem->count) == 0)
-                __rwsem_wake(sem, 0);
-}
-
-/*
- * Releasing the writer is easy -- just release it and wake up any sleepers.
- */
-extern inline void up_write(struct rw_semaphore *sem)
-{
-        int count;
-
-#if WAITQUEUE_DEBUG
-        CHECK_MAGIC(sem->__magic);
-        if (sem->granted & 3)
-                BUG();
-        if (atomic_read(&sem->readers))
-                BUG();
-        if (atomic_read(&sem->writers) != 1)
-                BUG();
-        atomic_dec(&sem->writers);
-#endif
-
-        mb();
-        count = atomic_add_return(RW_LOCK_BIAS, &sem->count);
-        if (count - RW_LOCK_BIAS < 0 && count >= 0) {
-                /* Only do the wake if we're no longer negative.  */
-                __rwsem_wake(sem, count);
-        }
 }
 
 #endif