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1da177e4 LT |
1 | /* $Id: atomic.h,v 1.3 2001/07/25 16:15:19 bjornw Exp $ */ |
2 | ||
3 | #ifndef __ASM_CRIS_ATOMIC__ | |
4 | #define __ASM_CRIS_ATOMIC__ | |
5 | ||
6 | #include <asm/system.h> | |
7 | ||
8 | /* | |
9 | * Atomic operations that C can't guarantee us. Useful for | |
10 | * resource counting etc.. | |
11 | */ | |
12 | ||
13 | /* | |
14 | * Make sure gcc doesn't try to be clever and move things around | |
15 | * on us. We need to use _exactly_ the address the user gave us, | |
16 | * not some alias that contains the same information. | |
17 | */ | |
18 | ||
19 | #define __atomic_fool_gcc(x) (*(struct { int a[100]; } *)x) | |
20 | ||
21 | typedef struct { int counter; } atomic_t; | |
22 | ||
23 | #define ATOMIC_INIT(i) { (i) } | |
24 | ||
25 | #define atomic_read(v) ((v)->counter) | |
26 | #define atomic_set(v,i) (((v)->counter) = (i)) | |
27 | ||
28 | /* These should be written in asm but we do it in C for now. */ | |
29 | ||
30 | extern __inline__ void atomic_add(int i, volatile atomic_t *v) | |
31 | { | |
32 | unsigned long flags; | |
33 | local_save_flags(flags); | |
34 | local_irq_disable(); | |
35 | v->counter += i; | |
36 | local_irq_restore(flags); | |
37 | } | |
38 | ||
39 | extern __inline__ void atomic_sub(int i, volatile atomic_t *v) | |
40 | { | |
41 | unsigned long flags; | |
42 | local_save_flags(flags); | |
43 | local_irq_disable(); | |
44 | v->counter -= i; | |
45 | local_irq_restore(flags); | |
46 | } | |
47 | ||
48 | extern __inline__ int atomic_add_return(int i, volatile atomic_t *v) | |
49 | { | |
50 | unsigned long flags; | |
51 | int retval; | |
52 | local_save_flags(flags); | |
53 | local_irq_disable(); | |
54 | retval = (v->counter += i); | |
55 | local_irq_restore(flags); | |
56 | return retval; | |
57 | } | |
58 | ||
59 | #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) | |
60 | ||
61 | extern __inline__ int atomic_sub_return(int i, volatile atomic_t *v) | |
62 | { | |
63 | unsigned long flags; | |
64 | int retval; | |
65 | local_save_flags(flags); | |
66 | local_irq_disable(); | |
67 | retval = (v->counter -= i); | |
68 | local_irq_restore(flags); | |
69 | return retval; | |
70 | } | |
71 | ||
72 | extern __inline__ int atomic_sub_and_test(int i, volatile atomic_t *v) | |
73 | { | |
74 | int retval; | |
75 | unsigned long flags; | |
76 | local_save_flags(flags); | |
77 | local_irq_disable(); | |
78 | retval = (v->counter -= i) == 0; | |
79 | local_irq_restore(flags); | |
80 | return retval; | |
81 | } | |
82 | ||
83 | extern __inline__ void atomic_inc(volatile atomic_t *v) | |
84 | { | |
85 | unsigned long flags; | |
86 | local_save_flags(flags); | |
87 | local_irq_disable(); | |
88 | (v->counter)++; | |
89 | local_irq_restore(flags); | |
90 | } | |
91 | ||
92 | extern __inline__ void atomic_dec(volatile atomic_t *v) | |
93 | { | |
94 | unsigned long flags; | |
95 | local_save_flags(flags); | |
96 | local_irq_disable(); | |
97 | (v->counter)--; | |
98 | local_irq_restore(flags); | |
99 | } | |
100 | ||
101 | extern __inline__ int atomic_inc_return(volatile atomic_t *v) | |
102 | { | |
103 | unsigned long flags; | |
104 | int retval; | |
105 | local_save_flags(flags); | |
106 | local_irq_disable(); | |
107 | retval = (v->counter)++; | |
108 | local_irq_restore(flags); | |
109 | return retval; | |
110 | } | |
111 | ||
112 | extern __inline__ int atomic_dec_return(volatile atomic_t *v) | |
113 | { | |
114 | unsigned long flags; | |
115 | int retval; | |
116 | local_save_flags(flags); | |
117 | local_irq_disable(); | |
118 | retval = (v->counter)--; | |
119 | local_irq_restore(flags); | |
120 | return retval; | |
121 | } | |
122 | extern __inline__ int atomic_dec_and_test(volatile atomic_t *v) | |
123 | { | |
124 | int retval; | |
125 | unsigned long flags; | |
126 | local_save_flags(flags); | |
127 | local_irq_disable(); | |
128 | retval = --(v->counter) == 0; | |
129 | local_irq_restore(flags); | |
130 | return retval; | |
131 | } | |
132 | ||
133 | extern __inline__ int atomic_inc_and_test(volatile atomic_t *v) | |
134 | { | |
135 | int retval; | |
136 | unsigned long flags; | |
137 | local_save_flags(flags); | |
138 | local_irq_disable(); | |
139 | retval = ++(v->counter) == 0; | |
140 | local_irq_restore(flags); | |
141 | return retval; | |
142 | } | |
143 | ||
144 | /* Atomic operations are already serializing */ | |
145 | #define smp_mb__before_atomic_dec() barrier() | |
146 | #define smp_mb__after_atomic_dec() barrier() | |
147 | #define smp_mb__before_atomic_inc() barrier() | |
148 | #define smp_mb__after_atomic_inc() barrier() | |
149 | ||
150 | #endif |