atomic.h: atomic_add_unless as inline. Remove system.h atomic.h circular dependency
[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 #include <asm/system.h>
19
20 /*
21  * On IA-64, counter must always be volatile to ensure that that the
22  * memory accesses are ordered.
23  */
24 typedef struct { volatile __s32 counter; } atomic_t;
25 typedef struct { volatile __s64 counter; } atomic64_t;
26
27 #define ATOMIC_INIT(i)          ((atomic_t) { (i) })
28 #define ATOMIC64_INIT(i)        ((atomic64_t) { (i) })
29
30 #define atomic_read(v)          ((v)->counter)
31 #define atomic64_read(v)        ((v)->counter)
32
33 #define atomic_set(v,i)         (((v)->counter) = (i))
34 #define atomic64_set(v,i)       (((v)->counter) = (i))
35
36 static __inline__ int
37 ia64_atomic_add (int i, atomic_t *v)
38 {
39         __s32 old, new;
40         CMPXCHG_BUGCHECK_DECL
41
42         do {
43                 CMPXCHG_BUGCHECK(v);
44                 old = atomic_read(v);
45                 new = old + i;
46         } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic_t)) != old);
47         return new;
48 }
49
50 static __inline__ int
51 ia64_atomic64_add (__s64 i, atomic64_t *v)
52 {
53         __s64 old, new;
54         CMPXCHG_BUGCHECK_DECL
55
56         do {
57                 CMPXCHG_BUGCHECK(v);
58                 old = atomic_read(v);
59                 new = old + i;
60         } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old);
61         return new;
62 }
63
64 static __inline__ int
65 ia64_atomic_sub (int i, atomic_t *v)
66 {
67         __s32 old, new;
68         CMPXCHG_BUGCHECK_DECL
69
70         do {
71                 CMPXCHG_BUGCHECK(v);
72                 old = atomic_read(v);
73                 new = old - i;
74         } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic_t)) != old);
75         return new;
76 }
77
78 static __inline__ int
79 ia64_atomic64_sub (__s64 i, atomic64_t *v)
80 {
81         __s64 old, new;
82         CMPXCHG_BUGCHECK_DECL
83
84         do {
85                 CMPXCHG_BUGCHECK(v);
86                 old = atomic_read(v);
87                 new = old - i;
88         } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old);
89         return new;
90 }
91
92 #define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
93 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
94
95 #define atomic64_cmpxchg(v, old, new) \
96         (cmpxchg(&((v)->counter), old, new))
97 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
98
99 static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
100 {
101         int c, old;
102         c = atomic_read(v);
103         for (;;) {
104                 if (unlikely(c == (u)))
105                         break;
106                 old = atomic_cmpxchg((v), c, c + (a));
107                 if (likely(old == c))
108                         break;
109                 c = old;
110         }
111         return c != (u);
112 }
113
114 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
115
116 static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
117 {
118         long c, old;
119         c = atomic64_read(v);
120         for (;;) {
121                 if (unlikely(c == (u)))
122                         break;
123                 old = atomic64_cmpxchg((v), c, c + (a));
124                 if (likely(old == c))
125                         break;
126                 c = old;
127         }
128         return c != (u);
129 }
130
131 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
132
133 #define atomic_add_return(i,v)                                          \
134 ({                                                                      \
135         int __ia64_aar_i = (i);                                         \
136         (__builtin_constant_p(i)                                        \
137          && (   (__ia64_aar_i ==  1) || (__ia64_aar_i ==   4)           \
138              || (__ia64_aar_i ==  8) || (__ia64_aar_i ==  16)           \
139              || (__ia64_aar_i == -1) || (__ia64_aar_i ==  -4)           \
140              || (__ia64_aar_i == -8) || (__ia64_aar_i == -16)))         \
141                 ? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter)       \
142                 : ia64_atomic_add(__ia64_aar_i, v);                     \
143 })
144
145 #define atomic64_add_return(i,v)                                        \
146 ({                                                                      \
147         long __ia64_aar_i = (i);                                        \
148         (__builtin_constant_p(i)                                        \
149          && (   (__ia64_aar_i ==  1) || (__ia64_aar_i ==   4)           \
150              || (__ia64_aar_i ==  8) || (__ia64_aar_i ==  16)           \
151              || (__ia64_aar_i == -1) || (__ia64_aar_i ==  -4)           \
152              || (__ia64_aar_i == -8) || (__ia64_aar_i == -16)))         \
153                 ? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter)       \
154                 : ia64_atomic64_add(__ia64_aar_i, v);                   \
155 })
156
157 /*
158  * Atomically add I to V and return TRUE if the resulting value is
159  * negative.
160  */
161 static __inline__ int
162 atomic_add_negative (int i, atomic_t *v)
163 {
164         return atomic_add_return(i, v) < 0;
165 }
166
167 static __inline__ int
168 atomic64_add_negative (__s64 i, atomic64_t *v)
169 {
170         return atomic64_add_return(i, v) < 0;
171 }
172
173 #define atomic_sub_return(i,v)                                          \
174 ({                                                                      \
175         int __ia64_asr_i = (i);                                         \
176         (__builtin_constant_p(i)                                        \
177          && (   (__ia64_asr_i ==   1) || (__ia64_asr_i ==   4)          \
178              || (__ia64_asr_i ==   8) || (__ia64_asr_i ==  16)          \
179              || (__ia64_asr_i ==  -1) || (__ia64_asr_i ==  -4)          \
180              || (__ia64_asr_i ==  -8) || (__ia64_asr_i == -16)))        \
181                 ? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter)      \
182                 : ia64_atomic_sub(__ia64_asr_i, v);                     \
183 })
184
185 #define atomic64_sub_return(i,v)                                        \
186 ({                                                                      \
187         long __ia64_asr_i = (i);                                        \
188         (__builtin_constant_p(i)                                        \
189          && (   (__ia64_asr_i ==   1) || (__ia64_asr_i ==   4)          \
190              || (__ia64_asr_i ==   8) || (__ia64_asr_i ==  16)          \
191              || (__ia64_asr_i ==  -1) || (__ia64_asr_i ==  -4)          \
192              || (__ia64_asr_i ==  -8) || (__ia64_asr_i == -16)))        \
193                 ? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter)      \
194                 : ia64_atomic64_sub(__ia64_asr_i, v);                   \
195 })
196
197 #define atomic_dec_return(v)            atomic_sub_return(1, (v))
198 #define atomic_inc_return(v)            atomic_add_return(1, (v))
199 #define atomic64_dec_return(v)          atomic64_sub_return(1, (v))
200 #define atomic64_inc_return(v)          atomic64_add_return(1, (v))
201
202 #define atomic_sub_and_test(i,v)        (atomic_sub_return((i), (v)) == 0)
203 #define atomic_dec_and_test(v)          (atomic_sub_return(1, (v)) == 0)
204 #define atomic_inc_and_test(v)          (atomic_add_return(1, (v)) == 0)
205 #define atomic64_sub_and_test(i,v)      (atomic64_sub_return((i), (v)) == 0)
206 #define atomic64_dec_and_test(v)        (atomic64_sub_return(1, (v)) == 0)
207 #define atomic64_inc_and_test(v)        (atomic64_add_return(1, (v)) == 0)
208
209 #define atomic_add(i,v)                 atomic_add_return((i), (v))
210 #define atomic_sub(i,v)                 atomic_sub_return((i), (v))
211 #define atomic_inc(v)                   atomic_add(1, (v))
212 #define atomic_dec(v)                   atomic_sub(1, (v))
213
214 #define atomic64_add(i,v)               atomic64_add_return((i), (v))
215 #define atomic64_sub(i,v)               atomic64_sub_return((i), (v))
216 #define atomic64_inc(v)                 atomic64_add(1, (v))
217 #define atomic64_dec(v)                 atomic64_sub(1, (v))
218
219 /* Atomic operations are already serializing */
220 #define smp_mb__before_atomic_dec()     barrier()
221 #define smp_mb__after_atomic_dec()      barrier()
222 #define smp_mb__before_atomic_inc()     barrier()
223 #define smp_mb__after_atomic_inc()      barrier()
224
225 #include <asm-generic/atomic.h>
226 #endif /* _ASM_IA64_ATOMIC_H */