Linux kernel mirror (for testing)
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1#ifndef __ARCH_M68K_ATOMIC__
2#define __ARCH_M68K_ATOMIC__
3
4
5#include <asm/system.h>
6
7/*
8 * Atomic operations that C can't guarantee us. Useful for
9 * resource counting etc..
10 */
11
12/*
13 * We do not have SMP m68k systems, so we don't have to deal with that.
14 */
15
16typedef struct { int counter; } atomic_t;
17#define ATOMIC_INIT(i) { (i) }
18
19#define atomic_read(v) ((v)->counter)
20#define atomic_set(v, i) (((v)->counter) = i)
21
22static inline void atomic_add(int i, atomic_t *v)
23{
24 __asm__ __volatile__("addl %1,%0" : "+m" (*v) : "id" (i));
25}
26
27static inline void atomic_sub(int i, atomic_t *v)
28{
29 __asm__ __volatile__("subl %1,%0" : "+m" (*v) : "id" (i));
30}
31
32static inline void atomic_inc(atomic_t *v)
33{
34 __asm__ __volatile__("addql #1,%0" : "+m" (*v));
35}
36
37static inline void atomic_dec(atomic_t *v)
38{
39 __asm__ __volatile__("subql #1,%0" : "+m" (*v));
40}
41
42static inline int atomic_dec_and_test(atomic_t *v)
43{
44 char c;
45 __asm__ __volatile__("subql #1,%1; seq %0" : "=d" (c), "+m" (*v));
46 return c != 0;
47}
48
49static inline int atomic_inc_and_test(atomic_t *v)
50{
51 char c;
52 __asm__ __volatile__("addql #1,%1; seq %0" : "=d" (c), "+m" (*v));
53 return c != 0;
54}
55
56#ifdef CONFIG_RMW_INSNS
57
58static inline int atomic_add_return(int i, atomic_t *v)
59{
60 int t, tmp;
61
62 __asm__ __volatile__(
63 "1: movel %2,%1\n"
64 " addl %3,%1\n"
65 " casl %2,%1,%0\n"
66 " jne 1b"
67 : "+m" (*v), "=&d" (t), "=&d" (tmp)
68 : "g" (i), "2" (atomic_read(v)));
69 return t;
70}
71
72static inline int atomic_sub_return(int i, atomic_t *v)
73{
74 int t, tmp;
75
76 __asm__ __volatile__(
77 "1: movel %2,%1\n"
78 " subl %3,%1\n"
79 " casl %2,%1,%0\n"
80 " jne 1b"
81 : "+m" (*v), "=&d" (t), "=&d" (tmp)
82 : "g" (i), "2" (atomic_read(v)));
83 return t;
84}
85
86#define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
87#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
88
89#else /* !CONFIG_RMW_INSNS */
90
91static inline int atomic_add_return(int i, atomic_t * v)
92{
93 unsigned long flags;
94 int t;
95
96 local_irq_save(flags);
97 t = atomic_read(v);
98 t += i;
99 atomic_set(v, t);
100 local_irq_restore(flags);
101
102 return t;
103}
104
105static inline int atomic_sub_return(int i, atomic_t * v)
106{
107 unsigned long flags;
108 int t;
109
110 local_irq_save(flags);
111 t = atomic_read(v);
112 t -= i;
113 atomic_set(v, t);
114 local_irq_restore(flags);
115
116 return t;
117}
118
119static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
120{
121 unsigned long flags;
122 int prev;
123
124 local_irq_save(flags);
125 prev = atomic_read(v);
126 if (prev == old)
127 atomic_set(v, new);
128 local_irq_restore(flags);
129 return prev;
130}
131
132static inline int atomic_xchg(atomic_t *v, int new)
133{
134 unsigned long flags;
135 int prev;
136
137 local_irq_save(flags);
138 prev = atomic_read(v);
139 atomic_set(v, new);
140 local_irq_restore(flags);
141 return prev;
142}
143
144#endif /* !CONFIG_RMW_INSNS */
145
146#define atomic_dec_return(v) atomic_sub_return(1, (v))
147#define atomic_inc_return(v) atomic_add_return(1, (v))
148
149static inline int atomic_sub_and_test(int i, atomic_t *v)
150{
151 char c;
152 __asm__ __volatile__("subl %2,%1; seq %0" : "=d" (c), "+m" (*v): "g" (i));
153 return c != 0;
154}
155
156static inline int atomic_add_negative(int i, atomic_t *v)
157{
158 char c;
159 __asm__ __volatile__("addl %2,%1; smi %0" : "=d" (c), "+m" (*v): "g" (i));
160 return c != 0;
161}
162
163static inline void atomic_clear_mask(unsigned long mask, unsigned long *v)
164{
165 __asm__ __volatile__("andl %1,%0" : "+m" (*v) : "id" (~(mask)));
166}
167
168static inline void atomic_set_mask(unsigned long mask, unsigned long *v)
169{
170 __asm__ __volatile__("orl %1,%0" : "+m" (*v) : "id" (mask));
171}
172
173static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
174{
175 int c, old;
176 c = atomic_read(v);
177 for (;;) {
178 if (unlikely(c == (u)))
179 break;
180 old = atomic_cmpxchg((v), c, c + (a));
181 if (likely(old == c))
182 break;
183 c = old;
184 }
185 return c != (u);
186}
187
188#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
189
190/* Atomic operations are already serializing */
191#define smp_mb__before_atomic_dec() barrier()
192#define smp_mb__after_atomic_dec() barrier()
193#define smp_mb__before_atomic_inc() barrier()
194#define smp_mb__after_atomic_inc() barrier()
195
196#include <asm-generic/atomic.h>
197#endif /* __ARCH_M68K_ATOMIC __ */