b16ad235c7ee797da4b4704f7793b02e1fe2b045
[linux-2.6.git] / include / asm-ia64 / atomic.h
1 #ifndef _ASM_IA64_ATOMIC_H
2 #define _ASM_IA64_ATOMIC_H
3
4 /*
5  * Atomic operations that C can't guarantee us.  Useful for
6  * resource counting etc..
7  *
8  * NOTE: don't mess with the types below!  The "unsigned long" and
9  * "int" types were carefully placed so as to ensure proper operation
10  * of the macros.
11  *
12  * Copyright (C) 1998, 1999, 2002-2003 Hewlett-Packard Co
13  *      David Mosberger-Tang <davidm@hpl.hp.com>
14  */
15 #include <linux/types.h>
16
17 #include <asm/intrinsics.h>
18
19 /*
20  * On IA-64, counter must always be volatile to ensure that that the
21  * memory accesses are ordered.
22  */
23 typedef struct { volatile __s32 counter; } atomic_t;
24 typedef struct { volatile __s64 counter; } atomic64_t;
25
26 #define ATOMIC_INIT(i)          ((atomic_t) { (i) })
27 #define ATOMIC64_INIT(i)        ((atomic64_t) { (i) })
28
29 #define atomic_read(v)          ((v)->counter)
30 #define atomic64_read(v)        ((v)->counter)
31
32 #define atomic_set(v,i)         (((v)->counter) = (i))
33 #define atomic64_set(v,i)       (((v)->counter) = (i))
34
35 static __inline__ int
36 ia64_atomic_add (int i, atomic_t *v)
37 {
38         __s32 old, new;
39         CMPXCHG_BUGCHECK_DECL
40
41         do {
42                 CMPXCHG_BUGCHECK(v);
43                 old = atomic_read(v);
44                 new = old + i;
45         } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic_t)) != old);
46         return new;
47 }
48
49 static __inline__ int
50 ia64_atomic64_add (__s64 i, atomic64_t *v)
51 {
52         __s64 old, new;
53         CMPXCHG_BUGCHECK_DECL
54
55         do {
56                 CMPXCHG_BUGCHECK(v);
57                 old = atomic_read(v);
58                 new = old + i;
59         } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old);
60         return new;
61 }
62
63 static __inline__ int
64 ia64_atomic_sub (int i, atomic_t *v)
65 {
66         __s32 old, new;
67         CMPXCHG_BUGCHECK_DECL
68
69         do {
70                 CMPXCHG_BUGCHECK(v);
71                 old = atomic_read(v);
72                 new = old - i;
73         } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic_t)) != old);
74         return new;
75 }
76
77 static __inline__ int
78 ia64_atomic64_sub (__s64 i, atomic64_t *v)
79 {
80         __s64 old, new;
81         CMPXCHG_BUGCHECK_DECL
82
83         do {
84                 CMPXCHG_BUGCHECK(v);
85                 old = atomic_read(v);
86                 new = old - i;
87         } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old);
88         return new;
89 }
90
91 #define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
92 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
93
94 #define atomic64_cmpxchg(v, old, new) \
95         (cmpxchg(&((v)->counter), old, new))
96 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
97
98 #define atomic_add_unless(v, a, u)                              \
99 ({                                                              \
100         __typeof__(v->counter) c, old;                          \
101         c = atomic_read(v);                                     \
102         for (;;) {                                              \
103                 if (unlikely(c == (u)))                         \
104                         break;                                  \
105                 old = atomic_cmpxchg((v), c, c + (a));          \
106                 if (likely(old == c))                           \
107                         break;                                  \
108                 c = old;                                        \
109         }                                                       \
110         c != (u);                                               \
111 })
112 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
113
114 #define atomic64_add_unless(v, a, u)                            \
115 ({                                                              \
116         __typeof__(v->counter) c, old;                          \
117         c = atomic64_read(v);                                   \
118         for (;;) {                                              \
119                 if (unlikely(c == (u)))                         \
120                         break;                                  \
121                 old = atomic64_cmpxchg((v), c, c + (a));        \
122                 if (likely(old == c))                           \
123                         break;                                  \
124                 c = old;                                        \
125         }                                                       \
126         c != (u);                                               \
127 })
128 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
129
130 #define atomic_add_return(i,v)                                          \
131 ({                                                                      \
132         int __ia64_aar_i = (i);                                         \
133         (__builtin_constant_p(i)                                        \
134          && (   (__ia64_aar_i ==  1) || (__ia64_aar_i ==   4)           \
135              || (__ia64_aar_i ==  8) || (__ia64_aar_i ==  16)           \
136              || (__ia64_aar_i == -1) || (__ia64_aar_i ==  -4)           \
137              || (__ia64_aar_i == -8) || (__ia64_aar_i == -16)))         \
138                 ? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter)       \
139                 : ia64_atomic_add(__ia64_aar_i, v);                     \
140 })
141
142 #define atomic64_add_return(i,v)                                        \
143 ({                                                                      \
144         long __ia64_aar_i = (i);                                        \
145         (__builtin_constant_p(i)                                        \
146          && (   (__ia64_aar_i ==  1) || (__ia64_aar_i ==   4)           \
147              || (__ia64_aar_i ==  8) || (__ia64_aar_i ==  16)           \
148              || (__ia64_aar_i == -1) || (__ia64_aar_i ==  -4)           \
149              || (__ia64_aar_i == -8) || (__ia64_aar_i == -16)))         \
150                 ? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter)       \
151                 : ia64_atomic64_add(__ia64_aar_i, v);                   \
152 })
153
154 /*
155  * Atomically add I to V and return TRUE if the resulting value is
156  * negative.
157  */
158 static __inline__ int
159 atomic_add_negative (int i, atomic_t *v)
160 {
161         return atomic_add_return(i, v) < 0;
162 }
163
164 static __inline__ int
165 atomic64_add_negative (__s64 i, atomic64_t *v)
166 {
167         return atomic64_add_return(i, v) < 0;
168 }
169
170 #define atomic_sub_return(i,v)                                          \
171 ({                                                                      \
172         int __ia64_asr_i = (i);                                         \
173         (__builtin_constant_p(i)                                        \
174          && (   (__ia64_asr_i ==   1) || (__ia64_asr_i ==   4)          \
175              || (__ia64_asr_i ==   8) || (__ia64_asr_i ==  16)          \
176              || (__ia64_asr_i ==  -1) || (__ia64_asr_i ==  -4)          \
177              || (__ia64_asr_i ==  -8) || (__ia64_asr_i == -16)))        \
178                 ? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter)      \
179                 : ia64_atomic_sub(__ia64_asr_i, v);                     \
180 })
181
182 #define atomic64_sub_return(i,v)                                        \
183 ({                                                                      \
184         long __ia64_asr_i = (i);                                        \
185         (__builtin_constant_p(i)                                        \
186          && (   (__ia64_asr_i ==   1) || (__ia64_asr_i ==   4)          \
187              || (__ia64_asr_i ==   8) || (__ia64_asr_i ==  16)          \
188              || (__ia64_asr_i ==  -1) || (__ia64_asr_i ==  -4)          \
189              || (__ia64_asr_i ==  -8) || (__ia64_asr_i == -16)))        \
190                 ? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter)      \
191                 : ia64_atomic64_sub(__ia64_asr_i, v);                   \
192 })
193
194 #define atomic_dec_return(v)            atomic_sub_return(1, (v))
195 #define atomic_inc_return(v)            atomic_add_return(1, (v))
196 #define atomic64_dec_return(v)          atomic64_sub_return(1, (v))
197 #define atomic64_inc_return(v)          atomic64_add_return(1, (v))
198
199 #define atomic_sub_and_test(i,v)        (atomic_sub_return((i), (v)) == 0)
200 #define atomic_dec_and_test(v)          (atomic_sub_return(1, (v)) == 0)
201 #define atomic_inc_and_test(v)          (atomic_add_return(1, (v)) == 0)
202 #define atomic64_sub_and_test(i,v)      (atomic64_sub_return((i), (v)) == 0)
203 #define atomic64_dec_and_test(v)        (atomic64_sub_return(1, (v)) == 0)
204 #define atomic64_inc_and_test(v)        (atomic64_add_return(1, (v)) == 0)
205
206 #define atomic_add(i,v)                 atomic_add_return((i), (v))
207 #define atomic_sub(i,v)                 atomic_sub_return((i), (v))
208 #define atomic_inc(v)                   atomic_add(1, (v))
209 #define atomic_dec(v)                   atomic_sub(1, (v))
210
211 #define atomic64_add(i,v)               atomic64_add_return((i), (v))
212 #define atomic64_sub(i,v)               atomic64_sub_return((i), (v))
213 #define atomic64_inc(v)                 atomic64_add(1, (v))
214 #define atomic64_dec(v)                 atomic64_sub(1, (v))
215
216 /* Atomic operations are already serializing */
217 #define smp_mb__before_atomic_dec()     barrier()
218 #define smp_mb__after_atomic_dec()      barrier()
219 #define smp_mb__before_atomic_inc()     barrier()
220 #define smp_mb__after_atomic_inc()      barrier()
221
222 #include <asm-generic/atomic.h>
223 #endif /* _ASM_IA64_ATOMIC_H */