diff options
-rw-r--r-- | include/linux/lockref.h | 66 | ||||
-rw-r--r-- | lib/Makefile | 1 | ||||
-rw-r--r-- | lib/lockref.c | 69 |
3 files changed, 74 insertions, 62 deletions
diff --git a/include/linux/lockref.h b/include/linux/lockref.h index 0ea026092d1d..4c0af31c8d47 100644 --- a/include/linux/lockref.h +++ b/include/linux/lockref.h @@ -21,67 +21,9 @@ struct lockref { unsigned int count; }; -/** - * lockref_get - Increments reference count unconditionally - * @lockcnt: pointer to lockref structure - * - * This operation is only valid if you already hold a reference - * to the object, so you know the count cannot be zero. - */ -static inline void lockref_get(struct lockref *lockref) -{ - spin_lock(&lockref->lock); - lockref->count++; - spin_unlock(&lockref->lock); -} - -/** - * lockref_get_not_zero - Increments count unless the count is 0 - * @lockcnt: pointer to lockref structure - * Return: 1 if count updated successfully or 0 if count is 0 - */ -static inline int lockref_get_not_zero(struct lockref *lockref) -{ - int retval = 0; - - spin_lock(&lockref->lock); - if (lockref->count) { - lockref->count++; - retval = 1; - } - spin_unlock(&lockref->lock); - return retval; -} - -/** - * lockref_get_or_lock - Increments count unless the count is 0 - * @lockcnt: pointer to lockref structure - * Return: 1 if count updated successfully or 0 if count was zero - * and we got the lock instead. - */ -static inline int lockref_get_or_lock(struct lockref *lockref) -{ - spin_lock(&lockref->lock); - if (!lockref->count) - return 0; - lockref->count++; - spin_unlock(&lockref->lock); - return 1; -} - -/** - * lockref_put_or_lock - decrements count unless count <= 1 before decrement - * @lockcnt: pointer to lockref structure - * Return: 1 if count updated successfully or 0 if count <= 1 and lock taken - */ -static inline int lockref_put_or_lock(struct lockref *lockref) -{ - spin_lock(&lockref->lock); - if (lockref->count <= 1) - return 0; - lockref->count--; - spin_unlock(&lockref->lock); - return 1; -} +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 *); #endif /* __LINUX_LOCKREF_H */ diff --git a/lib/Makefile b/lib/Makefile index 7baccfd8a4e9..f2cb3082697c 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -20,6 +20,7 @@ lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_SMP) += cpumask.o lib-y += kobject.o klist.o +obj-y += lockref.o obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \ diff --git a/lib/lockref.c b/lib/lockref.c new file mode 100644 index 000000000000..a9a4f4e1eff5 --- /dev/null +++ b/lib/lockref.c @@ -0,0 +1,69 @@ +#include <linux/export.h> +#include <linux/lockref.h> + +/** + * lockref_get - Increments reference count unconditionally + * @lockcnt: pointer to lockref structure + * + * This operation is only valid if you already hold a reference + * to the object, so you know the count cannot be zero. + */ +void lockref_get(struct lockref *lockref) +{ + spin_lock(&lockref->lock); + lockref->count++; + spin_unlock(&lockref->lock); +} +EXPORT_SYMBOL(lockref_get); + +/** + * lockref_get_not_zero - Increments count unless the count is 0 + * @lockcnt: pointer to lockref structure + * Return: 1 if count updated successfully or 0 if count was zero + */ +int lockref_get_not_zero(struct lockref *lockref) +{ + int retval = 0; + + spin_lock(&lockref->lock); + if (lockref->count) { + lockref->count++; + retval = 1; + } + spin_unlock(&lockref->lock); + return retval; +} +EXPORT_SYMBOL(lockref_get_not_zero); + +/** + * lockref_get_or_lock - Increments count unless the count is 0 + * @lockcnt: pointer to lockref structure + * Return: 1 if count updated successfully or 0 if count was zero + * and we got the lock instead. + */ +int lockref_get_or_lock(struct lockref *lockref) +{ + spin_lock(&lockref->lock); + if (!lockref->count) + return 0; + lockref->count++; + spin_unlock(&lockref->lock); + return 1; +} +EXPORT_SYMBOL(lockref_get_or_lock); + +/** + * lockref_put_or_lock - decrements count unless count <= 1 before decrement + * @lockcnt: pointer to lockref structure + * Return: 1 if count updated successfully or 0 if count <= 1 and lock taken + */ +int lockref_put_or_lock(struct lockref *lockref) +{ + spin_lock(&lockref->lock); + if (lockref->count <= 1) + return 0; + lockref->count--; + spin_unlock(&lockref->lock); + return 1; +} +EXPORT_SYMBOL(lockref_put_or_lock); |