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authorGreg Kroah-Hartman <gregkh@suse.de>2012-01-06 14:42:52 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2012-01-06 14:42:52 -0500
commitff4b8a57f0aaa2882d444ca44b2b9b333d22a4df (patch)
treed851c923f85566572112d4c0f884cff388a3cc05 /include/linux/kref.h
parent805a6af8dba5dfdd35ec35dc52ec0122400b2610 (diff)
parentea04018e6bc5ddb2f0466c0e5b986bd4901b7e8e (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.h77
1 files changed, 71 insertions, 6 deletions
diff --git a/include/linux/kref.h b/include/linux/kref.h
index d4a62ab2ee5e..abc0120b09b7 100644
--- a/include/linux/kref.h
+++ b/include/linux/kref.h
@@ -15,16 +15,81 @@
15#ifndef _KREF_H_ 15#ifndef _KREF_H_
16#define _KREF_H_ 16#define _KREF_H_
17 17
18#include <linux/types.h> 18#include <linux/bug.h>
19#include <linux/atomic.h>
19 20
20struct kref { 21struct kref {
21 atomic_t refcount; 22 atomic_t refcount;
22}; 23};
23 24
24void kref_init(struct kref *kref); 25/**
25void kref_get(struct kref *kref); 26 * kref_init - initialize object.
26int kref_put(struct kref *kref, void (*release) (struct kref *kref)); 27 * @kref: object in question.
27int kref_sub(struct kref *kref, unsigned int count, 28 */
28 void (*release) (struct kref *kref)); 29static inline void kref_init(struct kref *kref)
30{
31 atomic_set(&kref->refcount, 1);
32}
33
34/**
35 * kref_get - increment refcount for object.
36 * @kref: object.
37 */
38static inline void kref_get(struct kref *kref)
39{
40 WARN_ON(!atomic_read(&kref->refcount));
41 atomic_inc(&kref->refcount);
42}
29 43
44/**
45 * kref_sub - subtract a number of refcounts for object.
46 * @kref: object.
47 * @count: Number of recounts to subtract.
48 * @release: pointer to the function that will clean up the object when the
49 * last reference to the object is released.
50 * This pointer is required, and it is not acceptable to pass kfree
51 * in as this function. If the caller does pass kfree to this
52 * function, you will be publicly mocked mercilessly by the kref
53 * maintainer, and anyone else who happens to notice it. You have
54 * been warned.
55 *
56 * Subtract @count from the refcount, and if 0, call release().
57 * Return 1 if the object was removed, otherwise return 0. Beware, if this
58 * function returns 0, you still can not count on the kref from remaining in
59 * memory. Only use the return value if you want to see if the kref is now
60 * gone, not present.
61 */
62static inline int kref_sub(struct kref *kref, unsigned int count,
63 void (*release)(struct kref *kref))
64{
65 WARN_ON(release == NULL);
66
67 if (atomic_sub_and_test((int) count, &kref->refcount)) {
68 release(kref);
69 return 1;
70 }
71 return 0;
72}
73
74/**
75 * kref_put - decrement refcount for object.
76 * @kref: object.
77 * @release: pointer to the function that will clean up the object when the
78 * last reference to the object is released.
79 * This pointer is required, and it is not acceptable to pass kfree
80 * in as this function. If the caller does pass kfree to this
81 * function, you will be publicly mocked mercilessly by the kref
82 * maintainer, and anyone else who happens to notice it. You have
83 * been warned.
84 *
85 * Decrement the refcount, and if 0, call release().
86 * Return 1 if the object was removed, otherwise return 0. Beware, if this
87 * function returns 0, you still can not count on the kref from remaining in
88 * memory. Only use the return value if you want to see if the kref is now
89 * gone, not present.
90 */
91static inline int kref_put(struct kref *kref, void (*release)(struct kref *kref))
92{
93 return kref_sub(kref, 1, release);
94}
30#endif /* _KREF_H_ */ 95#endif /* _KREF_H_ */