diff options
author | Greg Kroah-Hartman <gregkh@suse.de> | 2012-01-06 11:42:52 -0800 |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2012-01-06 11:42:52 -0800 |
commit | ff4b8a57f0aaa2882d444ca44b2b9b333d22a4df (patch) | |
tree | d851c923f85566572112d4c0f884cff388a3cc05 /include/linux/kref.h | |
parent | 805a6af8dba5dfdd35ec35dc52ec0122400b2610 (diff) | |
parent | ea04018e6bc5ddb2f0466c0e5b986bd4901b7e8e (diff) |
Merge branch 'driver-core-next' into Linux 3.2
This resolves the conflict in the arch/arm/mach-s3c64xx/s3c6400.c file,
and it fixes the build error in the arch/x86/kernel/microcode_core.c
file, that the merge did not catch.
The microcode_core.c patch was provided by Stephen Rothwell
<sfr@canb.auug.org.au> who was invaluable in the merge issues involved
with the large sysdev removal process in the driver-core tree.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include/linux/kref.h')
-rw-r--r-- | include/linux/kref.h | 77 |
1 files changed, 71 insertions, 6 deletions
diff --git a/include/linux/kref.h b/include/linux/kref.h index d4a62ab2ee5..abc0120b09b 100644 --- a/include/linux/kref.h +++ b/include/linux/kref.h @@ -15,16 +15,81 @@ #ifndef _KREF_H_ #define _KREF_H_ -#include <linux/types.h> +#include <linux/bug.h> +#include <linux/atomic.h> struct kref { atomic_t refcount; }; -void kref_init(struct kref *kref); -void kref_get(struct kref *kref); -int kref_put(struct kref *kref, void (*release) (struct kref *kref)); -int kref_sub(struct kref *kref, unsigned int count, - void (*release) (struct kref *kref)); +/** + * kref_init - initialize object. + * @kref: object in question. + */ +static inline void kref_init(struct kref *kref) +{ + atomic_set(&kref->refcount, 1); +} + +/** + * kref_get - increment refcount for object. + * @kref: object. + */ +static inline void kref_get(struct kref *kref) +{ + WARN_ON(!atomic_read(&kref->refcount)); + atomic_inc(&kref->refcount); +} +/** + * kref_sub - subtract a number of refcounts for object. + * @kref: object. + * @count: Number of recounts to subtract. + * @release: pointer to the function that will clean up the object when the + * last reference to the object is released. + * This pointer is required, and it is not acceptable to pass kfree + * in as this function. If the caller does pass kfree to this + * function, you will be publicly mocked mercilessly by the kref + * maintainer, and anyone else who happens to notice it. You have + * been warned. + * + * Subtract @count from the refcount, and if 0, call release(). + * Return 1 if the object was removed, otherwise return 0. Beware, if this + * function returns 0, you still can not count on the kref from remaining in + * memory. Only use the return value if you want to see if the kref is now + * gone, not present. + */ +static inline int kref_sub(struct kref *kref, unsigned int count, + void (*release)(struct kref *kref)) +{ + WARN_ON(release == NULL); + + if (atomic_sub_and_test((int) count, &kref->refcount)) { + release(kref); + return 1; + } + return 0; +} + +/** + * kref_put - decrement refcount for object. + * @kref: object. + * @release: pointer to the function that will clean up the object when the + * last reference to the object is released. + * This pointer is required, and it is not acceptable to pass kfree + * in as this function. If the caller does pass kfree to this + * function, you will be publicly mocked mercilessly by the kref + * maintainer, and anyone else who happens to notice it. You have + * been warned. + * + * Decrement the refcount, and if 0, call release(). + * Return 1 if the object was removed, otherwise return 0. Beware, if this + * function returns 0, you still can not count on the kref from remaining in + * memory. Only use the return value if you want to see if the kref is now + * gone, not present. + */ +static inline int kref_put(struct kref *kref, void (*release)(struct kref *kref)) +{ + return kref_sub(kref, 1, release); +} #endif /* _KREF_H_ */ |