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1da177e4 LT |
1 | #ifndef __ASM_SH_ATOMIC_H |
2 | #define __ASM_SH_ATOMIC_H | |
3 | ||
4 | /* | |
5 | * Atomic operations that C can't guarantee us. Useful for | |
6 | * resource counting etc.. | |
7 | * | |
8 | */ | |
9 | ||
10 | typedef struct { volatile int counter; } atomic_t; | |
11 | ||
12 | #define ATOMIC_INIT(i) ( (atomic_t) { (i) } ) | |
13 | ||
14 | #define atomic_read(v) ((v)->counter) | |
15 | #define atomic_set(v,i) ((v)->counter = (i)) | |
16 | ||
e4c2cfee | 17 | #include <linux/compiler.h> |
1da177e4 LT |
18 | #include <asm/system.h> |
19 | ||
20 | /* | |
21 | * To get proper branch prediction for the main line, we must branch | |
22 | * forward to code at the end of this object's .text section, then | |
23 | * branch back to restart the operation. | |
24 | */ | |
25 | ||
26 | static __inline__ void atomic_add(int i, atomic_t * v) | |
27 | { | |
28 | unsigned long flags; | |
29 | ||
30 | local_irq_save(flags); | |
31 | *(long *)v += i; | |
32 | local_irq_restore(flags); | |
33 | } | |
34 | ||
35 | static __inline__ void atomic_sub(int i, atomic_t *v) | |
36 | { | |
37 | unsigned long flags; | |
38 | ||
39 | local_irq_save(flags); | |
40 | *(long *)v -= i; | |
41 | local_irq_restore(flags); | |
42 | } | |
43 | ||
44 | static __inline__ int atomic_add_return(int i, atomic_t * v) | |
45 | { | |
46 | unsigned long temp, flags; | |
47 | ||
48 | local_irq_save(flags); | |
49 | temp = *(long *)v; | |
50 | temp += i; | |
51 | *(long *)v = temp; | |
52 | local_irq_restore(flags); | |
53 | ||
54 | return temp; | |
55 | } | |
56 | ||
57 | #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) | |
58 | ||
59 | static __inline__ int atomic_sub_return(int i, atomic_t * v) | |
60 | { | |
61 | unsigned long temp, flags; | |
62 | ||
63 | local_irq_save(flags); | |
64 | temp = *(long *)v; | |
65 | temp -= i; | |
66 | *(long *)v = temp; | |
67 | local_irq_restore(flags); | |
68 | ||
69 | return temp; | |
70 | } | |
71 | ||
72 | #define atomic_dec_return(v) atomic_sub_return(1,(v)) | |
73 | #define atomic_inc_return(v) atomic_add_return(1,(v)) | |
74 | ||
75 | /* | |
76 | * atomic_inc_and_test - increment and test | |
77 | * @v: pointer of type atomic_t | |
78 | * | |
79 | * Atomically increments @v by 1 | |
80 | * and returns true if the result is zero, or false for all | |
81 | * other cases. | |
82 | */ | |
83 | #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) | |
84 | ||
85 | #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) | |
86 | #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) | |
87 | ||
88 | #define atomic_inc(v) atomic_add(1,(v)) | |
89 | #define atomic_dec(v) atomic_sub(1,(v)) | |
90 | ||
4a6dae6d NP |
91 | static inline int atomic_cmpxchg(atomic_t *v, int old, int new) |
92 | { | |
93 | int ret; | |
94 | unsigned long flags; | |
95 | ||
96 | local_irq_save(flags); | |
97 | ret = v->counter; | |
98 | if (likely(ret == old)) | |
99 | v->counter = new; | |
100 | local_irq_restore(flags); | |
101 | ||
102 | return ret; | |
103 | } | |
104 | ||
ffbf670f IM |
105 | #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) |
106 | ||
8426e1f6 NP |
107 | static inline int atomic_add_unless(atomic_t *v, int a, int u) |
108 | { | |
109 | int ret; | |
110 | unsigned long flags; | |
111 | ||
112 | local_irq_save(flags); | |
113 | ret = v->counter; | |
114 | if (ret != u) | |
115 | v->counter += a; | |
116 | local_irq_restore(flags); | |
117 | ||
118 | return ret != u; | |
119 | } | |
120 | #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) | |
121 | ||
1da177e4 LT |
122 | static __inline__ void atomic_clear_mask(unsigned int mask, atomic_t *v) |
123 | { | |
124 | unsigned long flags; | |
125 | ||
126 | local_irq_save(flags); | |
127 | *(long *)v &= ~mask; | |
128 | local_irq_restore(flags); | |
129 | } | |
130 | ||
131 | static __inline__ void atomic_set_mask(unsigned int mask, atomic_t *v) | |
132 | { | |
133 | unsigned long flags; | |
134 | ||
135 | local_irq_save(flags); | |
136 | *(long *)v |= mask; | |
137 | local_irq_restore(flags); | |
138 | } | |
139 | ||
140 | /* Atomic operations are already serializing on SH */ | |
141 | #define smp_mb__before_atomic_dec() barrier() | |
142 | #define smp_mb__after_atomic_dec() barrier() | |
143 | #define smp_mb__before_atomic_inc() barrier() | |
144 | #define smp_mb__after_atomic_inc() barrier() | |
145 | ||
d3cb4871 | 146 | #include <asm-generic/atomic.h> |
1da177e4 | 147 | #endif /* __ASM_SH_ATOMIC_H */ |