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[LV-kern-commit] CVS: kernel-2.4/include/asm-vax semaphore.h,1.2,1.3
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From: Kenn H. <ke...@us...> - 2001-01-29 00:44:48
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Update of /cvsroot/linux-vax/kernel-2.4/include/asm-vax
In directory usw-pr-cvs1:/tmp/cvs-serv26062
Modified Files:
semaphore.h
Log Message:
semaphore-helper.h
Index: semaphore.h
===================================================================
RCS file: /cvsroot/linux-vax/kernel-2.4/include/asm-vax/semaphore.h,v
retrieving revision 1.2
retrieving revision 1.3
diff -u -r1.2 -r1.3
--- semaphore.h 2001/01/18 15:52:28 1.2
+++ semaphore.h 2001/01/29 00:44:39 1.3
@@ -1,37 +1,29 @@
-#ifndef _VAX_SEMAPHORE_H
-#define _VAX_SEMAPHORE_H
-
-
/*
- * SMP- and interrupt-safe semaphores..
+ * $Id$
+ *
+ * VAX version based on S390 version
+ *
+ * S390 version
+ * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
*
- * (C) Copyright 1996 Linus Torvalds
- *
- * VAX port atp Nov 1998.
- * - this makes my brain hurt.
- * - updated for 2.4 Jan 2001. New wait_queue_head_t plus misc software rot.
- * Lifted from s390 and parisc
+ * Derived from "include/asm-i386/semaphore.h"
+ * (C) Copyright 1996 Linus Torvalds
*/
+
+#ifndef _VAX_SEMAPHORE_H
+#define _VAX_SEMAPHORE_H
+
#include <asm/system.h>
#include <asm/atomic.h>
-#include <linux/wait.h> /* wait_queue_head_t */
-#include <linux/linkage.h>
+#include <linux/wait.h>
struct semaphore {
atomic_t count;
- int waking;
+ int sleepers;
wait_queue_head_t wait;
-#if WAITQUEUE_DEBUG
- long __magic;
-#endif
};
-#if WAITQUEUE_DEBUG
-# define __SEM_DEBUG_INIT(name) \
- , (long)&(name).__magic
-#else
-# define __SEM_DEBUG_INIT(name)
-#endif
+#define __SEM_DEBUG_INIT(name)
#define __SEMAPHORE_INITIALIZER(name,count) \
{ ATOMIC_INIT(count), 0, __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
@@ -49,9 +41,6 @@
extern inline void sema_init (struct semaphore *sem, int val)
{
*sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val);
-#if WAITQUEUE_DEBUG
- sem->__magic = (long)&sem->__magic;
-#endif
}
static inline void init_MUTEX (struct semaphore *sem)
@@ -74,52 +63,32 @@
asmlinkage int __down_trylock(struct semaphore * sem);
asmlinkage void __up(struct semaphore * sem);
-extern spinlock_t semaphore_wake_lock;
-
-
-extern __inline__ void down(struct semaphore * sem)
+extern inline void down(struct semaphore * sem)
{
-#if WAITQUEUE_DEBUG
- CHECK_MAGIC(sem->__magic);
-#endif
-
if (atomic_dec_return(&sem->count) < 0)
__down(sem);
}
-extern __inline__ int down_interruptible(struct semaphore * sem)
+extern inline int down_interruptible(struct semaphore * sem)
{
int ret = 0;
-#if WAITQUEUE_DEBUG
- CHECK_MAGIC(sem->__magic);
-#endif
if (atomic_dec_return(&sem->count) < 0)
ret = __down_interruptible(sem);
return ret;
}
-extern __inline__ int down_trylock(struct semaphore * sem)
+extern inline int down_trylock(struct semaphore * sem)
{
int ret = 0;
-#if WAITQUEUE_DEBUG
- CHECK_MAGIC(sem->__magic);
-#endif
if (atomic_dec_return(&sem->count) < 0)
ret = __down_trylock(sem);
return ret;
}
-/*
- * Note! This is subtle. We jump to wake people up only if
- * the semaphore was negative (== somebody was waiting on it).
- */
-extern __inline__ void up(struct semaphore * sem)
+extern inline void up(struct semaphore * sem)
{
-#if WAITQUEUE_DEBUG
- CHECK_MAGIC(sem->__magic);
-#endif
if (atomic_inc_return(&sem->count) <= 0)
__up(sem);
}
@@ -143,38 +112,27 @@
* flopping back and forth between readers and writers
* under heavy use.
*
- * -ben
+ * -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
+ atomic_t count;
+ volatile unsigned int write_bias_granted;
+ volatile unsigned int read_bias_granted;
+ wait_queue_head_t wait;
+ wait_queue_head_t write_bias_wait;
};
-#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 RW_LOCK_BIAS 0x01000000
+#define __RWSEM_DEBUG_INIT /* */
#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 }
+{ ATOMIC_INIT(count), 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)
+ 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)
@@ -182,110 +140,55 @@
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));
+ 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);
+}
+extern void __down_read_failed(int, struct rw_semaphore *);
+extern void __down_write_failed(int, struct rw_semaphore *);
+extern void __rwsem_wake(int, struct rw_semaphore *);
+
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
+ int count;
+ count = atomic_dec_return(&sem->count);
+ if (count < 0)
+ __down_read_failed(count, sem);
}
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
+ int count;
+ count = atomic_add_return (-RW_LOCK_BIAS, &sem->count);
+ if (count < 0)
+ __down_write_failed(count, sem);
}
/* 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)
+extern inline void up_read(struct rw_semaphore *sem)
{
+ int count;
+ count = atomic_inc_return(&sem->count);
+ if (count == 0)
+ __rwsem_wake(count, 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);
+ int count;
+ count = atomic_add_return(RW_LOCK_BIAS, &sem->count);
+ if (count >= 0 && count < RW_LOCK_BIAS)
+ __rwsem_wake(count, sem);
}
+#endif /* _VAX_SEMAPHORE_H */
-#endif /* !(_VAX_SEMAPHORE_H) */
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