Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | #ifndef _ALPHA_ATOMIC_H |
2 | #define _ALPHA_ATOMIC_H | |
3 | ||
4 | /* | |
5 | * Atomic operations that C can't guarantee us. Useful for | |
6 | * resource counting etc... | |
7 | * | |
8 | * But use these as seldom as possible since they are much slower | |
9 | * than regular operations. | |
10 | */ | |
11 | ||
12 | ||
13 | /* | |
14 | * Counter is volatile to make sure gcc doesn't try to be clever | |
15 | * and move things around on us. We need to use _exactly_ the address | |
16 | * the user gave us, not some alias that contains the same information. | |
17 | */ | |
18 | typedef struct { volatile int counter; } atomic_t; | |
19 | typedef struct { volatile long counter; } atomic64_t; | |
20 | ||
21 | #define ATOMIC_INIT(i) ( (atomic_t) { (i) } ) | |
22 | #define ATOMIC64_INIT(i) ( (atomic64_t) { (i) } ) | |
23 | ||
24 | #define atomic_read(v) ((v)->counter + 0) | |
25 | #define atomic64_read(v) ((v)->counter + 0) | |
26 | ||
27 | #define atomic_set(v,i) ((v)->counter = (i)) | |
28 | #define atomic64_set(v,i) ((v)->counter = (i)) | |
29 | ||
30 | /* | |
31 | * To get proper branch prediction for the main line, we must branch | |
32 | * forward to code at the end of this object's .text section, then | |
33 | * branch back to restart the operation. | |
34 | */ | |
35 | ||
36 | static __inline__ void atomic_add(int i, atomic_t * v) | |
37 | { | |
38 | unsigned long temp; | |
39 | __asm__ __volatile__( | |
40 | "1: ldl_l %0,%1\n" | |
41 | " addl %0,%2,%0\n" | |
42 | " stl_c %0,%1\n" | |
43 | " beq %0,2f\n" | |
44 | ".subsection 2\n" | |
45 | "2: br 1b\n" | |
46 | ".previous" | |
47 | :"=&r" (temp), "=m" (v->counter) | |
48 | :"Ir" (i), "m" (v->counter)); | |
49 | } | |
50 | ||
51 | static __inline__ void atomic64_add(long i, atomic64_t * v) | |
52 | { | |
53 | unsigned long temp; | |
54 | __asm__ __volatile__( | |
55 | "1: ldq_l %0,%1\n" | |
56 | " addq %0,%2,%0\n" | |
57 | " stq_c %0,%1\n" | |
58 | " beq %0,2f\n" | |
59 | ".subsection 2\n" | |
60 | "2: br 1b\n" | |
61 | ".previous" | |
62 | :"=&r" (temp), "=m" (v->counter) | |
63 | :"Ir" (i), "m" (v->counter)); | |
64 | } | |
65 | ||
66 | static __inline__ void atomic_sub(int i, atomic_t * v) | |
67 | { | |
68 | unsigned long temp; | |
69 | __asm__ __volatile__( | |
70 | "1: ldl_l %0,%1\n" | |
71 | " subl %0,%2,%0\n" | |
72 | " stl_c %0,%1\n" | |
73 | " beq %0,2f\n" | |
74 | ".subsection 2\n" | |
75 | "2: br 1b\n" | |
76 | ".previous" | |
77 | :"=&r" (temp), "=m" (v->counter) | |
78 | :"Ir" (i), "m" (v->counter)); | |
79 | } | |
80 | ||
81 | static __inline__ void atomic64_sub(long i, atomic64_t * v) | |
82 | { | |
83 | unsigned long temp; | |
84 | __asm__ __volatile__( | |
85 | "1: ldq_l %0,%1\n" | |
86 | " subq %0,%2,%0\n" | |
87 | " stq_c %0,%1\n" | |
88 | " beq %0,2f\n" | |
89 | ".subsection 2\n" | |
90 | "2: br 1b\n" | |
91 | ".previous" | |
92 | :"=&r" (temp), "=m" (v->counter) | |
93 | :"Ir" (i), "m" (v->counter)); | |
94 | } | |
95 | ||
96 | ||
97 | /* | |
98 | * Same as above, but return the result value | |
99 | */ | |
100 | static __inline__ long atomic_add_return(int i, atomic_t * v) | |
101 | { | |
102 | long temp, result; | |
103 | __asm__ __volatile__( | |
104 | "1: ldl_l %0,%1\n" | |
105 | " addl %0,%3,%2\n" | |
106 | " addl %0,%3,%0\n" | |
107 | " stl_c %0,%1\n" | |
108 | " beq %0,2f\n" | |
109 | " mb\n" | |
110 | ".subsection 2\n" | |
111 | "2: br 1b\n" | |
112 | ".previous" | |
113 | :"=&r" (temp), "=m" (v->counter), "=&r" (result) | |
114 | :"Ir" (i), "m" (v->counter) : "memory"); | |
115 | return result; | |
116 | } | |
117 | ||
118 | #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) | |
119 | ||
120 | static __inline__ long atomic64_add_return(long i, atomic64_t * v) | |
121 | { | |
122 | long temp, result; | |
123 | __asm__ __volatile__( | |
124 | "1: ldq_l %0,%1\n" | |
125 | " addq %0,%3,%2\n" | |
126 | " addq %0,%3,%0\n" | |
127 | " stq_c %0,%1\n" | |
128 | " beq %0,2f\n" | |
129 | " mb\n" | |
130 | ".subsection 2\n" | |
131 | "2: br 1b\n" | |
132 | ".previous" | |
133 | :"=&r" (temp), "=m" (v->counter), "=&r" (result) | |
134 | :"Ir" (i), "m" (v->counter) : "memory"); | |
135 | return result; | |
136 | } | |
137 | ||
138 | static __inline__ long atomic_sub_return(int i, atomic_t * v) | |
139 | { | |
140 | long temp, result; | |
141 | __asm__ __volatile__( | |
142 | "1: ldl_l %0,%1\n" | |
143 | " subl %0,%3,%2\n" | |
144 | " subl %0,%3,%0\n" | |
145 | " stl_c %0,%1\n" | |
146 | " beq %0,2f\n" | |
147 | " mb\n" | |
148 | ".subsection 2\n" | |
149 | "2: br 1b\n" | |
150 | ".previous" | |
151 | :"=&r" (temp), "=m" (v->counter), "=&r" (result) | |
152 | :"Ir" (i), "m" (v->counter) : "memory"); | |
153 | return result; | |
154 | } | |
155 | ||
156 | static __inline__ long atomic64_sub_return(long i, atomic64_t * v) | |
157 | { | |
158 | long temp, result; | |
159 | __asm__ __volatile__( | |
160 | "1: ldq_l %0,%1\n" | |
161 | " subq %0,%3,%2\n" | |
162 | " subq %0,%3,%0\n" | |
163 | " stq_c %0,%1\n" | |
164 | " beq %0,2f\n" | |
165 | " mb\n" | |
166 | ".subsection 2\n" | |
167 | "2: br 1b\n" | |
168 | ".previous" | |
169 | :"=&r" (temp), "=m" (v->counter), "=&r" (result) | |
170 | :"Ir" (i), "m" (v->counter) : "memory"); | |
171 | return result; | |
172 | } | |
173 | ||
174 | #define atomic_dec_return(v) atomic_sub_return(1,(v)) | |
175 | #define atomic64_dec_return(v) atomic64_sub_return(1,(v)) | |
176 | ||
177 | #define atomic_inc_return(v) atomic_add_return(1,(v)) | |
178 | #define atomic64_inc_return(v) atomic64_add_return(1,(v)) | |
179 | ||
180 | #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) | |
181 | #define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0) | |
182 | ||
183 | #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0) | |
184 | #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) | |
185 | #define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0) | |
186 | ||
187 | #define atomic_inc(v) atomic_add(1,(v)) | |
188 | #define atomic64_inc(v) atomic64_add(1,(v)) | |
189 | ||
190 | #define atomic_dec(v) atomic_sub(1,(v)) | |
191 | #define atomic64_dec(v) atomic64_sub(1,(v)) | |
192 | ||
193 | #define smp_mb__before_atomic_dec() smp_mb() | |
194 | #define smp_mb__after_atomic_dec() smp_mb() | |
195 | #define smp_mb__before_atomic_inc() smp_mb() | |
196 | #define smp_mb__after_atomic_inc() smp_mb() | |
197 | ||
198 | #endif /* _ALPHA_ATOMIC_H */ |