atomic: cleanup asm-generic atomic*.h inclusion
[linux-2.6.git] / arch / tile / include / asm / atomic.h
1 /*
2  * Copyright 2010 Tilera Corporation. All Rights Reserved.
3  *
4  *   This program is free software; you can redistribute it and/or
5  *   modify it under the terms of the GNU General Public License
6  *   as published by the Free Software Foundation, version 2.
7  *
8  *   This program is distributed in the hope that it will be useful, but
9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11  *   NON INFRINGEMENT.  See the GNU General Public License for
12  *   more details.
13  *
14  * Atomic primitives.
15  */
16
17 #ifndef _ASM_TILE_ATOMIC_H
18 #define _ASM_TILE_ATOMIC_H
19
20 #ifndef __ASSEMBLY__
21
22 #include <linux/compiler.h>
23 #include <asm/system.h>
24
25 #define ATOMIC_INIT(i)  { (i) }
26
27 /**
28  * atomic_read - read atomic variable
29  * @v: pointer of type atomic_t
30  *
31  * Atomically reads the value of @v.
32  */
33 static inline int atomic_read(const atomic_t *v)
34 {
35         return ACCESS_ONCE(v->counter);
36 }
37
38 /**
39  * atomic_sub_return - subtract integer and return
40  * @v: pointer of type atomic_t
41  * @i: integer value to subtract
42  *
43  * Atomically subtracts @i from @v and returns @v - @i
44  */
45 #define atomic_sub_return(i, v)         atomic_add_return((int)(-(i)), (v))
46
47 /**
48  * atomic_sub - subtract integer from atomic variable
49  * @i: integer value to subtract
50  * @v: pointer of type atomic_t
51  *
52  * Atomically subtracts @i from @v.
53  */
54 #define atomic_sub(i, v)                atomic_add((int)(-(i)), (v))
55
56 /**
57  * atomic_sub_and_test - subtract value from variable and test result
58  * @i: integer value to subtract
59  * @v: pointer of type atomic_t
60  *
61  * Atomically subtracts @i from @v and returns true if the result is
62  * zero, or false for all other cases.
63  */
64 #define atomic_sub_and_test(i, v)       (atomic_sub_return((i), (v)) == 0)
65
66 /**
67  * atomic_inc_return - increment memory and return
68  * @v: pointer of type atomic_t
69  *
70  * Atomically increments @v by 1 and returns the new value.
71  */
72 #define atomic_inc_return(v)            atomic_add_return(1, (v))
73
74 /**
75  * atomic_dec_return - decrement memory and return
76  * @v: pointer of type atomic_t
77  *
78  * Atomically decrements @v by 1 and returns the new value.
79  */
80 #define atomic_dec_return(v)            atomic_sub_return(1, (v))
81
82 /**
83  * atomic_inc - increment atomic variable
84  * @v: pointer of type atomic_t
85  *
86  * Atomically increments @v by 1.
87  */
88 #define atomic_inc(v)                   atomic_add(1, (v))
89
90 /**
91  * atomic_dec - decrement atomic variable
92  * @v: pointer of type atomic_t
93  *
94  * Atomically decrements @v by 1.
95  */
96 #define atomic_dec(v)                   atomic_sub(1, (v))
97
98 /**
99  * atomic_dec_and_test - decrement and test
100  * @v: pointer of type atomic_t
101  *
102  * Atomically decrements @v by 1 and returns true if the result is 0.
103  */
104 #define atomic_dec_and_test(v)          (atomic_dec_return(v) == 0)
105
106 /**
107  * atomic_inc_and_test - increment and test
108  * @v: pointer of type atomic_t
109  *
110  * Atomically increments @v by 1 and returns true if the result is 0.
111  */
112 #define atomic_inc_and_test(v)          (atomic_inc_return(v) == 0)
113
114 /**
115  * atomic_add_negative - add and test if negative
116  * @v: pointer of type atomic_t
117  * @i: integer value to add
118  *
119  * Atomically adds @i to @v and returns true if the result is
120  * negative, or false when result is greater than or equal to zero.
121  */
122 #define atomic_add_negative(i, v)       (atomic_add_return((i), (v)) < 0)
123
124 /* Nonexistent functions intended to cause link errors. */
125 extern unsigned long __xchg_called_with_bad_pointer(void);
126 extern unsigned long __cmpxchg_called_with_bad_pointer(void);
127
128 #define xchg(ptr, x)                                                    \
129         ({                                                              \
130                 typeof(*(ptr)) __x;                                     \
131                 switch (sizeof(*(ptr))) {                               \
132                 case 4:                                                 \
133                         __x = (typeof(__x))(typeof(__x-__x))atomic_xchg( \
134                                 (atomic_t *)(ptr),                      \
135                                 (u32)(typeof((x)-(x)))(x));             \
136                         break;                                          \
137                 case 8:                                                 \
138                         __x = (typeof(__x))(typeof(__x-__x))atomic64_xchg( \
139                                 (atomic64_t *)(ptr),                    \
140                                 (u64)(typeof((x)-(x)))(x));             \
141                         break;                                          \
142                 default:                                                \
143                         __xchg_called_with_bad_pointer();               \
144                 }                                                       \
145                 __x;                                                    \
146         })
147
148 #define cmpxchg(ptr, o, n)                                              \
149         ({                                                              \
150                 typeof(*(ptr)) __x;                                     \
151                 switch (sizeof(*(ptr))) {                               \
152                 case 4:                                                 \
153                         __x = (typeof(__x))(typeof(__x-__x))atomic_cmpxchg( \
154                                 (atomic_t *)(ptr),                      \
155                                 (u32)(typeof((o)-(o)))(o),              \
156                                 (u32)(typeof((n)-(n)))(n));             \
157                         break;                                          \
158                 case 8:                                                 \
159                         __x = (typeof(__x))(typeof(__x-__x))atomic64_cmpxchg( \
160                                 (atomic64_t *)(ptr),                    \
161                                 (u64)(typeof((o)-(o)))(o),              \
162                                 (u64)(typeof((n)-(n)))(n));             \
163                         break;                                          \
164                 default:                                                \
165                         __cmpxchg_called_with_bad_pointer();            \
166                 }                                                       \
167                 __x;                                                    \
168         })
169
170 #define tas(ptr) (xchg((ptr), 1))
171
172 #endif /* __ASSEMBLY__ */
173
174 #ifndef __tilegx__
175 #include <asm/atomic_32.h>
176 #else
177 #include <asm/atomic_64.h>
178 #endif
179
180 #endif /* _ASM_TILE_ATOMIC_H */