patch-2.4.6 linux/include/asm-mips/semaphore.h
Next file: linux/include/asm-mips/serial.h
Previous file: linux/include/asm-mips/semaphore-helper.h
Back to the patch index
Back to the overall index
- Lines: 297
- Date:
Mon Jul 2 13:56:40 2001
- Orig file:
v2.4.5/linux/include/asm-mips/semaphore.h
- Orig date:
Tue Apr 17 17:19:31 2001
diff -u --recursive --new-file v2.4.5/linux/include/asm-mips/semaphore.h linux/include/asm-mips/semaphore.h
@@ -1,5 +1,4 @@
-/* $Id: semaphore.h,v 1.12 1999/12/08 22:05:10 harald Exp $
- *
+/*
* SMP- and interrupt-safe semaphores..
*
* This file is subject to the terms and conditions of the GNU General Public
@@ -9,6 +8,7 @@
* (C) Copyright 1996 Linus Torvalds
* (C) Copyright 1998, 1999, 2000 Ralf Baechle
* (C) Copyright 1999, 2000 Silicon Graphics, Inc.
+ * Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved.
*/
#ifndef _ASM_SEMAPHORE_H
#define _ASM_SEMAPHORE_H
@@ -60,7 +60,7 @@
#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0)
-extern inline void sema_init (struct semaphore *sem, int val)
+static inline void sema_init (struct semaphore *sem, int val)
{
atomic_set(&sem->count, val);
atomic_set(&sem->waking, 0);
@@ -85,7 +85,7 @@
asmlinkage int __down_trylock(struct semaphore * sem);
asmlinkage void __up(struct semaphore * sem);
-extern inline void down(struct semaphore * sem)
+static inline void down(struct semaphore * sem)
{
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
@@ -94,7 +94,7 @@
__down(sem);
}
-extern inline int down_interruptible(struct semaphore * sem)
+static inline int down_interruptible(struct semaphore * sem)
{
int ret = 0;
@@ -106,9 +106,9 @@
return ret;
}
-#if !defined(CONFIG_CPU_HAS_LLSC)
+#if !defined(CONFIG_CPU_HAS_LLSC) || defined(CONFIG_CPU_MIPS32)
-extern inline int down_trylock(struct semaphore * sem)
+static inline int down_trylock(struct semaphore * sem)
{
int ret = 0;
if (atomic_dec_return(&sem->count) < 0)
@@ -140,7 +140,7 @@
* }
* }
*/
-extern inline int down_trylock(struct semaphore * sem)
+static inline int down_trylock(struct semaphore * sem)
{
long ret, tmp, tmp2, sub;
@@ -148,29 +148,25 @@
CHECK_MAGIC(sem->__magic);
#endif
- __asm__ __volatile__("
- .set mips3
-
- 0: lld %1, %4
- dli %3, 0x0000000100000000
- dsubu %1, %3
- li %0, 0
- bgez %1, 2f
- sll %2, %1, 0
- blez %2, 1f
- daddiu %1, %1, -1
- b 2f
- 1:
- daddu %1, %1, %3
- li %0, 1
- 2:
- scd %1, %4
- beqz %1, 0b
-
- .set mips0"
- : "=&r"(ret), "=&r"(tmp), "=&r"(tmp2), "=&r"(sub)
- : "m"(*sem)
- : "memory");
+ __asm__ __volatile__(
+ ".set\tmips3\t\t\t# down_trylock\n"
+ "0:\tlld\t%1, %4\n\t"
+ "dli\t%3, 0x0000000100000000\n\t"
+ "dsubu\t%1, %3\n\t"
+ "li\t%0, 0\n\t"
+ "bgez\t%1, 2f\n\t"
+ "sll\t%2, %1, 0\n\t"
+ "blez\t%2, 1f\n\t"
+ "daddiu\t%1, %1, -1\n\t"
+ "b\t2f\n\t"
+ "1:\tdaddu\t%1, %1, %3\n"
+ "li\t%0, 1\n"
+ "2:\tscd\t%1, %4\n\t"
+ "beqz\t%1, 0b\n\t"
+ ".set mips0"
+ : "=&r"(ret), "=&r"(tmp), "=&r"(tmp2), "=&r"(sub)
+ : "m"(*sem)
+ : "memory");
return ret;
}
@@ -181,183 +177,13 @@
* 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)
+static inline void up(struct semaphore * sem)
{
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#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 subtracting BIAS once per CPU will result
- * in the int remaining negative. In terms of fairness, this should result
- * in the lock flopping back and forth between readers and writers under
- * heavy use.
- *
- * Once we start supporting machines with more than 128 CPUs, we should go
- * for using a 64bit atomic type instead of 32bit as counter. We shall
- * probably go for bias 0x80000000 then, so that single sethi can set it.
- * */
-
-#define RW_LOCK_BIAS 0x01000000
-
-struct rw_semaphore {
- atomic_t count;
- /* bit 0 means read bias granted;
- bit 1 means write bias granted. */
- unsigned long granted; /* pedant: long req'd for set_bit */
- 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 /* _ASM_SEMAPHORE_H */
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)