diff options
| author | John Stultz <john.stultz@linaro.org> | 2013-09-26 12:05:54 -0700 |
|---|---|---|
| committer | John Stultz <john.stultz@linaro.org> | 2013-09-26 12:05:54 -0700 |
| commit | 17deb9c2db01c7813611291d251d8c7dbdfd3c9d (patch) | |
| tree | 6e023c0be7c64de84dd51a671eb09c5c82b56615 /include/linux/lockref.h | |
| parent | f4e6e1ea19737077d958f2bc6c196eb579d97544 (diff) | |
| parent | 389e067032fbb96e439abafae848dd447e4cafb4 (diff) | |
Merge remote-tracking branch 'tip/timers/core' into fordlezcano/3.13/sched-clock64-conversion
Update to tip/timers/core and resolve minor conflict.
Conflicts:
drivers/clocksource/samsung_pwm_timer.c
Signed-off-by: John Stultz <john.stultz@linaro.org>
Diffstat (limited to 'include/linux/lockref.h')
| -rw-r--r-- | include/linux/lockref.h | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/include/linux/lockref.h b/include/linux/lockref.h new file mode 100644 index 000000000000..f279ed9a9163 --- /dev/null +++ b/include/linux/lockref.h @@ -0,0 +1,39 @@ +#ifndef __LINUX_LOCKREF_H +#define __LINUX_LOCKREF_H + +/* + * Locked reference counts. + * + * These are different from just plain atomic refcounts in that they + * are atomic with respect to the spinlock that goes with them. In + * particular, there can be implementations that don't actually get + * the spinlock for the common decrement/increment operations, but they + * still have to check that the operation is done semantically as if + * the spinlock had been taken (using a cmpxchg operation that covers + * both the lock and the count word, or using memory transactions, for + * example). + */ + +#include <linux/spinlock.h> + +struct lockref { + union { +#ifdef CONFIG_CMPXCHG_LOCKREF + aligned_u64 lock_count; +#endif + struct { + spinlock_t lock; + unsigned int count; + }; + }; +}; + +extern void lockref_get(struct lockref *); +extern int lockref_get_not_zero(struct lockref *); +extern int lockref_get_or_lock(struct lockref *); +extern int lockref_put_or_lock(struct lockref *); + +extern void lockref_mark_dead(struct lockref *); +extern int lockref_get_not_dead(struct lockref *); + +#endif /* __LINUX_LOCKREF_H */ |
