patch-2.4.4 linux/include/asm-i386/semaphore.h

• Lines: 195
• Date: Fri Apr 27 15:48:27 2001
• Orig file: v2.4.3/linux/include/asm-i386/semaphore.h
• Orig date: Mon Mar 26 15:48:11 2001

diff -u --recursive --new-file v2.4.3/linux/include/asm-i386/semaphore.h linux/include/asm-i386/semaphore.h
@@ -38,8 +38,8 @@
 
 #include <asm/system.h>
 #include <asm/atomic.h>
-#include <asm/rwlock.h>
 #include <linux/wait.h>
+#include <linux/rwsem.h>
 
 struct semaphore {
 	atomic_t count;
@@ -202,184 +202,6 @@
 		:"=m" (sem->count)
 		:"c" (sem)
 		:"memory");
-}
-
-/* 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 __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)
-
-static 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
-}
-
-/* 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));
-
-static inline void down_read(struct rw_semaphore *sem)
-{
-#if WAITQUEUE_DEBUG
-	if (sem->__magic != (long)&sem->__magic)
-		BUG();
-#endif
-	__build_read_lock(sem, "__down_read_failed");
-#if WAITQUEUE_DEBUG
-	if (sem->write_bias_granted)
-		BUG();
-	if (atomic_read(&sem->writers))
-		BUG();
-	atomic_inc(&sem->readers);
-#endif
-}
-
-static inline void down_write(struct rw_semaphore *sem)
-{
-#if WAITQUEUE_DEBUG
-	if (sem->__magic != (long)&sem->__magic)
-		BUG();
-#endif
-	__build_write_lock(sem, "__down_write_failed");
-#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.
- */
-static inline void __up_read(struct rw_semaphore *sem)
-{
-	__asm__ __volatile__(
-		"# up_read\n\t"
-		LOCK "incl %0\n\t"
-		"jz 2f\n"			/* only do the wake if result == 0 (ie, a writer) */
-		"1:\n\t"
-		".section .text.lock,\"ax\"\n"
-		"2:\tcall __rwsem_wake\n\t"
-		"jmp 1b\n"
-		".previous"
-		:"=m" (sem->count)
-		:"a" (sem)
-		:"memory"
-		);
-}
-
-/* releasing the writer is easy -- just release it and
- * wake up any sleepers.
- */
-static inline void __up_write(struct rw_semaphore *sem)
-{
-	__asm__ __volatile__(
-		"# up_write\n\t"
-		LOCK "addl $" RW_LOCK_BIAS_STR ",%0\n"
-		"jc 2f\n"			/* only do the wake if the result was -'ve to 0/+'ve */
-		"1:\n\t"
-		".section .text.lock,\"ax\"\n"
-		"2:\tcall __rwsem_wake\n\t"
-		"jmp 1b\n"
-		".previous"
-		:"=m" (sem->count)
-		:"a" (sem)
-		:"memory"
-		);
-}
-
-static 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);
-}
-
-static 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