diff options
Diffstat (limited to 'include/linux/spinlock_up.h')
-rw-r--r-- | include/linux/spinlock_up.h | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/include/linux/spinlock_up.h b/include/linux/spinlock_up.h new file mode 100644 index 0000000..31accf2 --- /dev/null +++ b/include/linux/spinlock_up.h @@ -0,0 +1,74 @@ +#ifndef __LINUX_SPINLOCK_UP_H +#define __LINUX_SPINLOCK_UP_H + +#ifndef __LINUX_SPINLOCK_H +# error "please don't include this file directly" +#endif + +/* + * include/linux/spinlock_up.h - UP-debug version of spinlocks. + * + * portions Copyright 2005, Red Hat, Inc., Ingo Molnar + * Released under the General Public License (GPL). + * + * In the debug case, 1 means unlocked, 0 means locked. (the values + * are inverted, to catch initialization bugs) + * + * No atomicity anywhere, we are on UP. + */ + +#ifdef CONFIG_DEBUG_SPINLOCK + +#define __raw_spin_is_locked(x) ((x)->slock == 0) + +static inline void __raw_spin_lock(raw_spinlock_t *lock) +{ + lock->slock = 0; +} + +static inline void +__raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags) +{ + local_irq_save(flags); + lock->slock = 0; +} + +static inline int __raw_spin_trylock(raw_spinlock_t *lock) +{ + char oldval = lock->slock; + + lock->slock = 0; + + return oldval > 0; +} + +static inline void __raw_spin_unlock(raw_spinlock_t *lock) +{ + lock->slock = 1; +} + +/* + * Read-write spinlocks. No debug version. + */ +#define __raw_read_lock(lock) do { (void)(lock); } while (0) +#define __raw_write_lock(lock) do { (void)(lock); } while (0) +#define __raw_read_trylock(lock) ({ (void)(lock); 1; }) +#define __raw_write_trylock(lock) ({ (void)(lock); 1; }) +#define __raw_read_unlock(lock) do { (void)(lock); } while (0) +#define __raw_write_unlock(lock) do { (void)(lock); } while (0) + +#else /* DEBUG_SPINLOCK */ +#define __raw_spin_is_locked(lock) ((void)(lock), 0) +/* for sched.c and kernel_lock.c: */ +# define __raw_spin_lock(lock) do { (void)(lock); } while (0) +# define __raw_spin_unlock(lock) do { (void)(lock); } while (0) +# define __raw_spin_trylock(lock) ({ (void)(lock); 1; }) +#endif /* DEBUG_SPINLOCK */ + +#define __raw_read_can_lock(lock) (((void)(lock), 1)) +#define __raw_write_can_lock(lock) (((void)(lock), 1)) + +#define __raw_spin_unlock_wait(lock) \ + do { cpu_relax(); } while (__raw_spin_is_locked(lock)) + +#endif /* __LINUX_SPINLOCK_UP_H */ |