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author | Chris Zankel <czankel@tensilica.com> | 2005-06-24 05:01:26 (GMT) |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-06-24 07:05:22 (GMT) |
commit | 9a8fd5589902153a134111ed7a40f9cca1f83254 (patch) | |
tree | 6f7a06de25bdf0b2d94623794c2cbbc66b5a77f6 /include/asm-xtensa/semaphore.h | |
parent | 3f65ce4d141e435e54c20ed2379d983d362a2cb5 (diff) | |
download | linux-9a8fd5589902153a134111ed7a40f9cca1f83254.tar.xz |
[PATCH] xtensa: Architecture support for Tensilica Xtensa Part 6
The attached patches provides part 6 of an architecture implementation for the
Tensilica Xtensa CPU series.
Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/asm-xtensa/semaphore.h')
-rw-r--r-- | include/asm-xtensa/semaphore.h | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/include/asm-xtensa/semaphore.h b/include/asm-xtensa/semaphore.h new file mode 100644 index 0000000..c8a7574 --- /dev/null +++ b/include/asm-xtensa/semaphore.h @@ -0,0 +1,129 @@ +/* + * linux/include/asm-xtensa/semaphore.h + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2005 Tensilica Inc. + */ + +#ifndef _XTENSA_SEMAPHORE_H +#define _XTENSA_SEMAPHORE_H + +#include <asm/atomic.h> +#include <asm/system.h> +#include <linux/wait.h> +#include <linux/rwsem.h> + +struct semaphore { + atomic_t count; + int sleepers; + wait_queue_head_t wait; +#if WAITQUEUE_DEBUG + long __magic; +#endif +}; + +#if WAITQUEUE_DEBUG +# define __SEM_DEBUG_INIT(name) \ + , (int)&(name).__magic +#else +# define __SEM_DEBUG_INIT(name) +#endif + +#define __SEMAPHORE_INITIALIZER(name,count) \ + { ATOMIC_INIT(count), \ + 0, \ + __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ + __SEM_DEBUG_INIT(name) } + +#define __MUTEX_INITIALIZER(name) \ + __SEMAPHORE_INITIALIZER(name, 1) + +#define __DECLARE_SEMAPHORE_GENERIC(name,count) \ + struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) + +#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) +{ +/* + * *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val); + * + * i'd rather use the more flexible initialization above, but sadly + * GCC 2.7.2.3 emits a bogus warning. EGCS doesnt. Oh well. + */ + atomic_set(&sem->count, val); + init_waitqueue_head(&sem->wait); +#if WAITQUEUE_DEBUG + sem->__magic = (int)&sem->__magic; +#endif +} + +static inline void init_MUTEX (struct semaphore *sem) +{ + sema_init(sem, 1); +} + +static inline void init_MUTEX_LOCKED (struct semaphore *sem) +{ + sema_init(sem, 0); +} + +asmlinkage void __down(struct semaphore * sem); +asmlinkage int __down_interruptible(struct semaphore * sem); +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) +{ +#if WAITQUEUE_DEBUG + CHECK_MAGIC(sem->__magic); +#endif + + if (atomic_sub_return(1, &sem->count) < 0) + __down(sem); +} + +extern __inline__ int down_interruptible(struct semaphore * sem) +{ + int ret = 0; +#if WAITQUEUE_DEBUG + CHECK_MAGIC(sem->__magic); +#endif + + if (atomic_sub_return(1, &sem->count) < 0) + ret = __down_interruptible(sem); + return ret; +} + +extern __inline__ int down_trylock(struct semaphore * sem) +{ + int ret = 0; +#if WAITQUEUE_DEBUG + CHECK_MAGIC(sem->__magic); +#endif + + if (atomic_sub_return(1, &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) +{ +#if WAITQUEUE_DEBUG + CHECK_MAGIC(sem->__magic); +#endif + if (atomic_add_return(1, &sem->count) <= 0) + __up(sem); +} + +#endif /* _XTENSA_SEMAPHORE_H */ |