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Linux kernel mirror (for testing)
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1/*
2 * Copyright 2011 Tilera Corporation. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
12 * more details.
13 *
14 * Do not include directly; use <linux/atomic.h>.
15 */
16
17#ifndef _ASM_TILE_ATOMIC_64_H
18#define _ASM_TILE_ATOMIC_64_H
19
20#ifndef __ASSEMBLY__
21
22#include <asm/barrier.h>
23#include <arch/spr_def.h>
24
25/* First, the 32-bit atomic ops that are "real" on our 64-bit platform. */
26
27#define atomic_set(v, i) ((v)->counter = (i))
28
29/*
30 * The smp_mb() operations throughout are to support the fact that
31 * Linux requires memory barriers before and after the operation,
32 * on any routine which updates memory and returns a value.
33 */
34
35static inline int atomic_cmpxchg(atomic_t *v, int o, int n)
36{
37 int val;
38 __insn_mtspr(SPR_CMPEXCH_VALUE, o);
39 smp_mb(); /* barrier for proper semantics */
40 val = __insn_cmpexch4((void *)&v->counter, n);
41 smp_mb(); /* barrier for proper semantics */
42 return val;
43}
44
45static inline int atomic_xchg(atomic_t *v, int n)
46{
47 int val;
48 smp_mb(); /* barrier for proper semantics */
49 val = __insn_exch4((void *)&v->counter, n);
50 smp_mb(); /* barrier for proper semantics */
51 return val;
52}
53
54static inline void atomic_add(int i, atomic_t *v)
55{
56 __insn_fetchadd4((void *)&v->counter, i);
57}
58
59static inline int atomic_add_return(int i, atomic_t *v)
60{
61 int val;
62 smp_mb(); /* barrier for proper semantics */
63 val = __insn_fetchadd4((void *)&v->counter, i) + i;
64 barrier(); /* the "+ i" above will wait on memory */
65 return val;
66}
67
68static inline int __atomic_add_unless(atomic_t *v, int a, int u)
69{
70 int guess, oldval = v->counter;
71 do {
72 if (oldval == u)
73 break;
74 guess = oldval;
75 oldval = atomic_cmpxchg(v, guess, guess + a);
76 } while (guess != oldval);
77 return oldval;
78}
79
80/* Now the true 64-bit operations. */
81
82#define ATOMIC64_INIT(i) { (i) }
83
84#define atomic64_read(v) ((v)->counter)
85#define atomic64_set(v, i) ((v)->counter = (i))
86
87static inline long atomic64_cmpxchg(atomic64_t *v, long o, long n)
88{
89 long val;
90 smp_mb(); /* barrier for proper semantics */
91 __insn_mtspr(SPR_CMPEXCH_VALUE, o);
92 val = __insn_cmpexch((void *)&v->counter, n);
93 smp_mb(); /* barrier for proper semantics */
94 return val;
95}
96
97static inline long atomic64_xchg(atomic64_t *v, long n)
98{
99 long val;
100 smp_mb(); /* barrier for proper semantics */
101 val = __insn_exch((void *)&v->counter, n);
102 smp_mb(); /* barrier for proper semantics */
103 return val;
104}
105
106static inline void atomic64_add(long i, atomic64_t *v)
107{
108 __insn_fetchadd((void *)&v->counter, i);
109}
110
111static inline long atomic64_add_return(long i, atomic64_t *v)
112{
113 int val;
114 smp_mb(); /* barrier for proper semantics */
115 val = __insn_fetchadd((void *)&v->counter, i) + i;
116 barrier(); /* the "+ i" above will wait on memory */
117 return val;
118}
119
120static inline long atomic64_add_unless(atomic64_t *v, long a, long u)
121{
122 long guess, oldval = v->counter;
123 do {
124 if (oldval == u)
125 break;
126 guess = oldval;
127 oldval = atomic64_cmpxchg(v, guess, guess + a);
128 } while (guess != oldval);
129 return oldval != u;
130}
131
132#define atomic64_sub_return(i, v) atomic64_add_return(-(i), (v))
133#define atomic64_sub(i, v) atomic64_add(-(i), (v))
134#define atomic64_inc_return(v) atomic64_add_return(1, (v))
135#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
136#define atomic64_inc(v) atomic64_add(1, (v))
137#define atomic64_dec(v) atomic64_sub(1, (v))
138
139#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
140#define atomic64_dec_and_test(v) (atomic64_dec_return(v) == 0)
141#define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0)
142#define atomic64_add_negative(i, v) (atomic64_add_return((i), (v)) < 0)
143
144#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
145
146/* Atomic dec and inc don't implement barrier, so provide them if needed. */
147#define smp_mb__before_atomic_dec() smp_mb()
148#define smp_mb__after_atomic_dec() smp_mb()
149#define smp_mb__before_atomic_inc() smp_mb()
150#define smp_mb__after_atomic_inc() smp_mb()
151
152/* Define this to indicate that cmpxchg is an efficient operation. */
153#define __HAVE_ARCH_CMPXCHG
154
155#endif /* !__ASSEMBLY__ */
156
157#endif /* _ASM_TILE_ATOMIC_64_H */