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b920de1b DH |
1 | /* MN10300 Atomic counter operations |
2 | * | |
3 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public Licence | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the Licence, or (at your option) any later version. | |
10 | */ | |
11 | #ifndef _ASM_ATOMIC_H | |
12 | #define _ASM_ATOMIC_H | |
13 | ||
14 | #ifdef CONFIG_SMP | |
15 | #error not SMP safe | |
16 | #endif | |
17 | ||
18 | /* | |
19 | * Atomic operations that C can't guarantee us. Useful for | |
20 | * resource counting etc.. | |
21 | */ | |
22 | ||
b920de1b DH |
23 | #define ATOMIC_INIT(i) { (i) } |
24 | ||
25 | #ifdef __KERNEL__ | |
26 | ||
27 | /** | |
28 | * atomic_read - read atomic variable | |
29 | * @v: pointer of type atomic_t | |
30 | * | |
31 | * Atomically reads the value of @v. Note that the guaranteed | |
32 | * useful range of an atomic_t is only 24 bits. | |
33 | */ | |
34 | #define atomic_read(v) ((v)->counter) | |
35 | ||
36 | /** | |
37 | * atomic_set - set atomic variable | |
38 | * @v: pointer of type atomic_t | |
39 | * @i: required value | |
40 | * | |
41 | * Atomically sets the value of @v to @i. Note that the guaranteed | |
42 | * useful range of an atomic_t is only 24 bits. | |
43 | */ | |
44 | #define atomic_set(v, i) (((v)->counter) = (i)) | |
45 | ||
46 | #include <asm/system.h> | |
47 | ||
48 | /** | |
49 | * atomic_add_return - add integer to atomic variable | |
50 | * @i: integer value to add | |
51 | * @v: pointer of type atomic_t | |
52 | * | |
53 | * Atomically adds @i to @v and returns the result | |
54 | * Note that the guaranteed useful range of an atomic_t is only 24 bits. | |
55 | */ | |
56 | static inline int atomic_add_return(int i, atomic_t *v) | |
57 | { | |
58 | unsigned long flags; | |
59 | int temp; | |
60 | ||
61 | local_irq_save(flags); | |
62 | temp = v->counter; | |
63 | temp += i; | |
64 | v->counter = temp; | |
65 | local_irq_restore(flags); | |
66 | ||
67 | return temp; | |
68 | } | |
69 | ||
70 | /** | |
71 | * atomic_sub_return - subtract integer from atomic variable | |
72 | * @i: integer value to subtract | |
73 | * @v: pointer of type atomic_t | |
74 | * | |
75 | * Atomically subtracts @i from @v and returns the result | |
76 | * Note that the guaranteed useful range of an atomic_t is only 24 bits. | |
77 | */ | |
78 | static inline int atomic_sub_return(int i, atomic_t *v) | |
79 | { | |
80 | unsigned long flags; | |
81 | int temp; | |
82 | ||
83 | local_irq_save(flags); | |
84 | temp = v->counter; | |
85 | temp -= i; | |
86 | v->counter = temp; | |
87 | local_irq_restore(flags); | |
88 | ||
89 | return temp; | |
90 | } | |
91 | ||
92 | static inline int atomic_add_negative(int i, atomic_t *v) | |
93 | { | |
94 | return atomic_add_return(i, v) < 0; | |
95 | } | |
96 | ||
97 | static inline void atomic_add(int i, atomic_t *v) | |
98 | { | |
99 | atomic_add_return(i, v); | |
100 | } | |
101 | ||
102 | static inline void atomic_sub(int i, atomic_t *v) | |
103 | { | |
104 | atomic_sub_return(i, v); | |
105 | } | |
106 | ||
107 | static inline void atomic_inc(atomic_t *v) | |
108 | { | |
109 | atomic_add_return(1, v); | |
110 | } | |
111 | ||
112 | static inline void atomic_dec(atomic_t *v) | |
113 | { | |
114 | atomic_sub_return(1, v); | |
115 | } | |
116 | ||
117 | #define atomic_dec_return(v) atomic_sub_return(1, (v)) | |
118 | #define atomic_inc_return(v) atomic_add_return(1, (v)) | |
119 | ||
120 | #define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0) | |
121 | #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) | |
122 | #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0) | |
123 | ||
124 | #define atomic_add_unless(v, a, u) \ | |
125 | ({ \ | |
126 | int c, old; \ | |
127 | c = atomic_read(v); \ | |
128 | while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ | |
129 | c = old; \ | |
130 | c != (u); \ | |
131 | }) | |
132 | ||
133 | #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) | |
134 | ||
135 | static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) | |
136 | { | |
137 | unsigned long flags; | |
138 | ||
139 | mask = ~mask; | |
140 | local_irq_save(flags); | |
141 | *addr &= mask; | |
142 | local_irq_restore(flags); | |
143 | } | |
144 | ||
145 | #define atomic_xchg(ptr, v) (xchg(&(ptr)->counter, (v))) | |
146 | #define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new))) | |
147 | ||
148 | /* Atomic operations are already serializing on MN10300??? */ | |
149 | #define smp_mb__before_atomic_dec() barrier() | |
150 | #define smp_mb__after_atomic_dec() barrier() | |
151 | #define smp_mb__before_atomic_inc() barrier() | |
152 | #define smp_mb__after_atomic_inc() barrier() | |
153 | ||
154 | #include <asm-generic/atomic.h> | |
155 | ||
156 | #endif /* __KERNEL__ */ | |
157 | #endif /* _ASM_ATOMIC_H */ |