1 #ifndef __ASM_METAG_ATOMIC_LOCK1_H
2 #define __ASM_METAG_ATOMIC_LOCK1_H
3
4 #define ATOMIC_INIT(i) { (i) }
5
6 #include <linux/compiler.h>
7
8 #include <asm/barrier.h>
9 #include <asm/global_lock.h>
10
atomic_read(const atomic_t * v)11 static inline int atomic_read(const atomic_t *v)
12 {
13 return READ_ONCE((v)->counter);
14 }
15
16 /*
17 * atomic_set needs to be take the lock to protect atomic_add_unless from a
18 * possible race, as it reads the counter twice:
19 *
20 * CPU0 CPU1
21 * atomic_add_unless(1, 0)
22 * ret = v->counter (non-zero)
23 * if (ret != u) v->counter = 0
24 * v->counter += 1 (counter set to 1)
25 *
26 * Making atomic_set take the lock ensures that ordering and logical
27 * consistency is preserved.
28 */
atomic_set(atomic_t * v,int i)29 static inline int atomic_set(atomic_t *v, int i)
30 {
31 unsigned long flags;
32
33 __global_lock1(flags);
34 fence();
35 v->counter = i;
36 __global_unlock1(flags);
37 return i;
38 }
39
40 #define ATOMIC_OP(op, c_op) \
41 static inline void atomic_##op(int i, atomic_t *v) \
42 { \
43 unsigned long flags; \
44 \
45 __global_lock1(flags); \
46 fence(); \
47 v->counter c_op i; \
48 __global_unlock1(flags); \
49 } \
50
51 #define ATOMIC_OP_RETURN(op, c_op) \
52 static inline int atomic_##op##_return(int i, atomic_t *v) \
53 { \
54 unsigned long result; \
55 unsigned long flags; \
56 \
57 __global_lock1(flags); \
58 result = v->counter; \
59 result c_op i; \
60 fence(); \
61 v->counter = result; \
62 __global_unlock1(flags); \
63 \
64 return result; \
65 }
66
67 #define ATOMIC_OPS(op, c_op) ATOMIC_OP(op, c_op) ATOMIC_OP_RETURN(op, c_op)
68
69 ATOMIC_OPS(add, +=)
70 ATOMIC_OPS(sub, -=)
71 ATOMIC_OP(and, &=)
72 ATOMIC_OP(or, |=)
73 ATOMIC_OP(xor, ^=)
74
75 #undef ATOMIC_OPS
76 #undef ATOMIC_OP_RETURN
77 #undef ATOMIC_OP
78
atomic_cmpxchg(atomic_t * v,int old,int new)79 static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
80 {
81 int ret;
82 unsigned long flags;
83
84 __global_lock1(flags);
85 ret = v->counter;
86 if (ret == old) {
87 fence();
88 v->counter = new;
89 }
90 __global_unlock1(flags);
91
92 return ret;
93 }
94
95 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
96
__atomic_add_unless(atomic_t * v,int a,int u)97 static inline int __atomic_add_unless(atomic_t *v, int a, int u)
98 {
99 int ret;
100 unsigned long flags;
101
102 __global_lock1(flags);
103 ret = v->counter;
104 if (ret != u) {
105 fence();
106 v->counter += a;
107 }
108 __global_unlock1(flags);
109
110 return ret;
111 }
112
atomic_sub_if_positive(int i,atomic_t * v)113 static inline int atomic_sub_if_positive(int i, atomic_t *v)
114 {
115 int ret;
116 unsigned long flags;
117
118 __global_lock1(flags);
119 ret = v->counter - 1;
120 if (ret >= 0) {
121 fence();
122 v->counter = ret;
123 }
124 __global_unlock1(flags);
125
126 return ret;
127 }
128
129 #endif /* __ASM_METAG_ATOMIC_LOCK1_H */
130