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atomic.h
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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 <[email protected]>
14  */
15 #include <linux/types.h>
16 
17 #include <asm/intrinsics.h>
18 
19 
20 #define ATOMIC_INIT(i) { (i) }
21 #define ATOMIC64_INIT(i) { (i) }
22 
23 #define atomic_read(v) (*(volatile int *)&(v)->counter)
24 #define atomic64_read(v) (*(volatile long *)&(v)->counter)
25 
26 #define atomic_set(v,i) (((v)->counter) = (i))
27 #define atomic64_set(v,i) (((v)->counter) = (i))
28 
29 static __inline__ int
30 ia64_atomic_add (int i, atomic_t *v)
31 {
32  __s32 old, new;
33  CMPXCHG_BUGCHECK_DECL
34 
35  do {
36  CMPXCHG_BUGCHECK(v);
37  old = atomic_read(v);
38  new = old + i;
39  } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic_t)) != old);
40  return new;
41 }
42 
43 static __inline__ long
44 ia64_atomic64_add (__s64 i, atomic64_t *v)
45 {
46  __s64 old, new;
47  CMPXCHG_BUGCHECK_DECL
48 
49  do {
50  CMPXCHG_BUGCHECK(v);
51  old = atomic64_read(v);
52  new = old + i;
53  } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old);
54  return new;
55 }
56 
57 static __inline__ int
58 ia64_atomic_sub (int i, atomic_t *v)
59 {
60  __s32 old, new;
61  CMPXCHG_BUGCHECK_DECL
62 
63  do {
64  CMPXCHG_BUGCHECK(v);
65  old = atomic_read(v);
66  new = old - i;
67  } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic_t)) != old);
68  return new;
69 }
70 
71 static __inline__ long
72 ia64_atomic64_sub (__s64 i, atomic64_t *v)
73 {
74  __s64 old, new;
75  CMPXCHG_BUGCHECK_DECL
76 
77  do {
78  CMPXCHG_BUGCHECK(v);
79  old = atomic64_read(v);
80  new = old - i;
81  } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old);
82  return new;
83 }
84 
85 #define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
86 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
87 
88 #define atomic64_cmpxchg(v, old, new) \
89  (cmpxchg(&((v)->counter), old, new))
90 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
91 
92 static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
93 {
94  int c, old;
95  c = atomic_read(v);
96  for (;;) {
97  if (unlikely(c == (u)))
98  break;
99  old = atomic_cmpxchg((v), c, c + (a));
100  if (likely(old == c))
101  break;
102  c = old;
103  }
104  return c;
105 }
106 
107 
108 static __inline__ long atomic64_add_unless(atomic64_t *v, long a, long u)
109 {
110  long c, old;
111  c = atomic64_read(v);
112  for (;;) {
113  if (unlikely(c == (u)))
114  break;
115  old = atomic64_cmpxchg((v), c, c + (a));
116  if (likely(old == c))
117  break;
118  c = old;
119  }
120  return c != (u);
121 }
122 
123 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
124 
125 #define atomic_add_return(i,v) \
126 ({ \
127  int __ia64_aar_i = (i); \
128  (__builtin_constant_p(i) \
129  && ( (__ia64_aar_i == 1) || (__ia64_aar_i == 4) \
130  || (__ia64_aar_i == 8) || (__ia64_aar_i == 16) \
131  || (__ia64_aar_i == -1) || (__ia64_aar_i == -4) \
132  || (__ia64_aar_i == -8) || (__ia64_aar_i == -16))) \
133  ? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter) \
134  : ia64_atomic_add(__ia64_aar_i, v); \
135 })
136 
137 #define atomic64_add_return(i,v) \
138 ({ \
139  long __ia64_aar_i = (i); \
140  (__builtin_constant_p(i) \
141  && ( (__ia64_aar_i == 1) || (__ia64_aar_i == 4) \
142  || (__ia64_aar_i == 8) || (__ia64_aar_i == 16) \
143  || (__ia64_aar_i == -1) || (__ia64_aar_i == -4) \
144  || (__ia64_aar_i == -8) || (__ia64_aar_i == -16))) \
145  ? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter) \
146  : ia64_atomic64_add(__ia64_aar_i, v); \
147 })
148 
149 /*
150  * Atomically add I to V and return TRUE if the resulting value is
151  * negative.
152  */
153 static __inline__ int
154 atomic_add_negative (int i, atomic_t *v)
155 {
156  return atomic_add_return(i, v) < 0;
157 }
158 
159 static __inline__ long
160 atomic64_add_negative (__s64 i, atomic64_t *v)
161 {
162  return atomic64_add_return(i, v) < 0;
163 }
164 
165 #define atomic_sub_return(i,v) \
166 ({ \
167  int __ia64_asr_i = (i); \
168  (__builtin_constant_p(i) \
169  && ( (__ia64_asr_i == 1) || (__ia64_asr_i == 4) \
170  || (__ia64_asr_i == 8) || (__ia64_asr_i == 16) \
171  || (__ia64_asr_i == -1) || (__ia64_asr_i == -4) \
172  || (__ia64_asr_i == -8) || (__ia64_asr_i == -16))) \
173  ? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter) \
174  : ia64_atomic_sub(__ia64_asr_i, v); \
175 })
176 
177 #define atomic64_sub_return(i,v) \
178 ({ \
179  long __ia64_asr_i = (i); \
180  (__builtin_constant_p(i) \
181  && ( (__ia64_asr_i == 1) || (__ia64_asr_i == 4) \
182  || (__ia64_asr_i == 8) || (__ia64_asr_i == 16) \
183  || (__ia64_asr_i == -1) || (__ia64_asr_i == -4) \
184  || (__ia64_asr_i == -8) || (__ia64_asr_i == -16))) \
185  ? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter) \
186  : ia64_atomic64_sub(__ia64_asr_i, v); \
187 })
188 
189 #define atomic_dec_return(v) atomic_sub_return(1, (v))
190 #define atomic_inc_return(v) atomic_add_return(1, (v))
191 #define atomic64_dec_return(v) atomic64_sub_return(1, (v))
192 #define atomic64_inc_return(v) atomic64_add_return(1, (v))
193 
194 #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
195 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
196 #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
197 #define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)
198 #define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
199 #define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0)
200 
201 #define atomic_add(i,v) atomic_add_return((i), (v))
202 #define atomic_sub(i,v) atomic_sub_return((i), (v))
203 #define atomic_inc(v) atomic_add(1, (v))
204 #define atomic_dec(v) atomic_sub(1, (v))
205 
206 #define atomic64_add(i,v) atomic64_add_return((i), (v))
207 #define atomic64_sub(i,v) atomic64_sub_return((i), (v))
208 #define atomic64_inc(v) atomic64_add(1, (v))
209 #define atomic64_dec(v) atomic64_sub(1, (v))
210 
211 /* Atomic operations are already serializing */
212 #define smp_mb__before_atomic_dec() barrier()
213 #define smp_mb__after_atomic_dec() barrier()
214 #define smp_mb__before_atomic_inc() barrier()
215 #define smp_mb__after_atomic_inc() barrier()
216 
217 #endif /* _ASM_IA64_ATOMIC_H */
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