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8021q: fix a potential memory leak
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1 /* Atomic operations usable in machine independent code */
2 #ifndef _LINUX_ATOMIC_H
3 #define _LINUX_ATOMIC_H
4 #include <asm/atomic.h>
5
6 /*
7 * Provide __deprecated wrappers for the new interface, avoid flag day changes.
8 * We need the ugly external functions to break header recursion hell.
9 */
10 #ifndef smp_mb__before_atomic_inc
11 static inline void __deprecated smp_mb__before_atomic_inc(void)
12 {
13 extern void __smp_mb__before_atomic(void);
14 __smp_mb__before_atomic();
15 }
16 #endif
17
18 #ifndef smp_mb__after_atomic_inc
19 static inline void __deprecated smp_mb__after_atomic_inc(void)
20 {
21 extern void __smp_mb__after_atomic(void);
22 __smp_mb__after_atomic();
23 }
24 #endif
25
26 #ifndef smp_mb__before_atomic_dec
27 static inline void __deprecated smp_mb__before_atomic_dec(void)
28 {
29 extern void __smp_mb__before_atomic(void);
30 __smp_mb__before_atomic();
31 }
32 #endif
33
34 #ifndef smp_mb__after_atomic_dec
35 static inline void __deprecated smp_mb__after_atomic_dec(void)
36 {
37 extern void __smp_mb__after_atomic(void);
38 __smp_mb__after_atomic();
39 }
40 #endif
41
42 /**
43 * atomic_add_unless - add unless the number is already a given value
44 * @v: pointer of type atomic_t
45 * @a: the amount to add to v...
46 * @u: ...unless v is equal to u.
47 *
48 * Atomically adds @a to @v, so long as @v was not already @u.
49 * Returns non-zero if @v was not @u, and zero otherwise.
50 */
51 static inline int atomic_add_unless(atomic_t *v, int a, int u)
52 {
53 return __atomic_add_unless(v, a, u) != u;
54 }
55
56 /**
57 * atomic_inc_not_zero - increment unless the number is zero
58 * @v: pointer of type atomic_t
59 *
60 * Atomically increments @v by 1, so long as @v is non-zero.
61 * Returns non-zero if @v was non-zero, and zero otherwise.
62 */
63 #ifndef atomic_inc_not_zero
64 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
65 #endif
66
67 /**
68 * atomic_inc_not_zero_hint - increment if not null
69 * @v: pointer of type atomic_t
70 * @hint: probable value of the atomic before the increment
71 *
72 * This version of atomic_inc_not_zero() gives a hint of probable
73 * value of the atomic. This helps processor to not read the memory
74 * before doing the atomic read/modify/write cycle, lowering
75 * number of bus transactions on some arches.
76 *
77 * Returns: 0 if increment was not done, 1 otherwise.
78 */
79 #ifndef atomic_inc_not_zero_hint
80 static inline int atomic_inc_not_zero_hint(atomic_t *v, int hint)
81 {
82 int val, c = hint;
83
84 /* sanity test, should be removed by compiler if hint is a constant */
85 if (!hint)
86 return atomic_inc_not_zero(v);
87
88 do {
89 val = atomic_cmpxchg(v, c, c + 1);
90 if (val == c)
91 return 1;
92 c = val;
93 } while (c);
94
95 return 0;
96 }
97 #endif
98
99 #ifndef atomic_inc_unless_negative
100 static inline int atomic_inc_unless_negative(atomic_t *p)
101 {
102 int v, v1;
103 for (v = 0; v >= 0; v = v1) {
104 v1 = atomic_cmpxchg(p, v, v + 1);
105 if (likely(v1 == v))
106 return 1;
107 }
108 return 0;
109 }
110 #endif
111
112 #ifndef atomic_dec_unless_positive
113 static inline int atomic_dec_unless_positive(atomic_t *p)
114 {
115 int v, v1;
116 for (v = 0; v <= 0; v = v1) {
117 v1 = atomic_cmpxchg(p, v, v - 1);
118 if (likely(v1 == v))
119 return 1;
120 }
121 return 0;
122 }
123 #endif
124
125 /*
126 * atomic_dec_if_positive - decrement by 1 if old value positive
127 * @v: pointer of type atomic_t
128 *
129 * The function returns the old value of *v minus 1, even if
130 * the atomic variable, v, was not decremented.
131 */
132 #ifndef atomic_dec_if_positive
133 static inline int atomic_dec_if_positive(atomic_t *v)
134 {
135 int c, old, dec;
136 c = atomic_read(v);
137 for (;;) {
138 dec = c - 1;
139 if (unlikely(dec < 0))
140 break;
141 old = atomic_cmpxchg((v), c, dec);
142 if (likely(old == c))
143 break;
144 c = old;
145 }
146 return dec;
147 }
148 #endif
149
150 #ifndef CONFIG_ARCH_HAS_ATOMIC_OR
151 static inline void atomic_or(int i, atomic_t *v)
152 {
153 int old;
154 int new;
155
156 do {
157 old = atomic_read(v);
158 new = old | i;
159 } while (atomic_cmpxchg(v, old, new) != old);
160 }
161 #endif /* #ifndef CONFIG_ARCH_HAS_ATOMIC_OR */
162
163 #include <asm-generic/atomic-long.h>
164 #ifdef CONFIG_GENERIC_ATOMIC64
165 #include <asm-generic/atomic64.h>
166 #endif
167 #endif /* _LINUX_ATOMIC_H */