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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-m68knommu/semaphore-helper.h | |
download | lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/asm-m68knommu/semaphore-helper.h')
-rw-r--r-- | include/asm-m68knommu/semaphore-helper.h | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/include/asm-m68knommu/semaphore-helper.h b/include/asm-m68knommu/semaphore-helper.h new file mode 100644 index 000000000000..a6586417c1c2 --- /dev/null +++ b/include/asm-m68knommu/semaphore-helper.h @@ -0,0 +1,83 @@ +#ifndef _M68K_SEMAPHORE_HELPER_H +#define _M68K_SEMAPHORE_HELPER_H + +/* + * SMP- and interrupt-safe semaphores helper functions. + * + * (C) Copyright 1996 Linus Torvalds + * + * m68k version by Andreas Schwab + */ + +#include <linux/config.h> + +/* + * These two _must_ execute atomically wrt each other. + */ +static inline void wake_one_more(struct semaphore * sem) +{ + atomic_inc(&sem->waking); +} + +static inline int waking_non_zero(struct semaphore *sem) +{ + int ret; + unsigned long flags; + + spin_lock_irqsave(&semaphore_wake_lock, flags); + ret = 0; + if (atomic_read(&sem->waking) > 0) { + atomic_dec(&sem->waking); + ret = 1; + } + spin_unlock_irqrestore(&semaphore_wake_lock, flags); + return ret; +} + +/* + * waking_non_zero_interruptible: + * 1 got the lock + * 0 go to sleep + * -EINTR interrupted + */ +static inline int waking_non_zero_interruptible(struct semaphore *sem, + struct task_struct *tsk) +{ + int ret; + unsigned long flags; + + spin_lock_irqsave(&semaphore_wake_lock, flags); + ret = 0; + if (atomic_read(&sem->waking) > 0) { + atomic_dec(&sem->waking); + ret = 1; + } else if (signal_pending(tsk)) { + atomic_inc(&sem->count); + ret = -EINTR; + } + spin_unlock_irqrestore(&semaphore_wake_lock, flags); + return ret; +} + +/* + * waking_non_zero_trylock: + * 1 failed to lock + * 0 got the lock + */ +static inline int waking_non_zero_trylock(struct semaphore *sem) +{ + int ret; + unsigned long flags; + + spin_lock_irqsave(&semaphore_wake_lock, flags); + ret = 1; + if (atomic_read(&sem->waking) > 0) { + atomic_dec(&sem->waking); + ret = 0; + } else + atomic_inc(&sem->count); + spin_unlock_irqrestore(&semaphore_wake_lock, flags); + return ret; +} + +#endif |