| #include <linux/module.h> |
| #include <linux/spinlock.h> |
| * This is an architecture-neutral, but slow, |
| * implementation of the notion of "decrement |
| * a reference count, and return locked if it |
| * NOTE NOTE NOTE! This is _not_ equivalent to |
| * if (atomic_dec_and_test(&atomic)) { |
| * because the spin-lock and the decrement must be |
| * This slow version gets the spinlock unconditionally, |
| * and releases it if it isn't needed. Architectures |
| * are encouraged to come up with better approaches, |
| * this is trivially done efficiently using a load-locked |
| * store-conditional approach, for example. |
| #ifndef ATOMIC_DEC_AND_LOCK |
| int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock) |
| if (atomic_dec_and_test(atomic)) |
| EXPORT_SYMBOL(_atomic_dec_and_lock); |