lockref: uninline lockref helper functions (2f4f12e5) · Commits · 戴 / test

include/linux/lockref.h

+4 −62

Original line number	Diff line number	Diff line
		@@ -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 */

lib/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -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 \

lib/lockref.c

0 → 100644

+69 −0

Original line number	Diff line number	Diff line
		#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);

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