Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * atomic32.c: 32-bit atomic_t implementation
4 *
5 * Copyright (C) 2004 Keith M Wesolowski
6 * Copyright (C) 2007 Kyle McMartin
7 *
8 * Based on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf
9 */
10
11#include <linux/atomic.h>
12#include <linux/spinlock.h>
13#include <linux/module.h>
14
15#ifdef CONFIG_SMP
16#define ATOMIC_HASH_SIZE 4
17#define ATOMIC_HASH(a) (&__atomic_hash[(((unsigned long)a)>>8) & (ATOMIC_HASH_SIZE-1)])
18
19spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] = {
20 [0 ... (ATOMIC_HASH_SIZE-1)] = __SPIN_LOCK_UNLOCKED(__atomic_hash)
21};
22
23#else /* SMP */
24
25static DEFINE_SPINLOCK(dummy);
26#define ATOMIC_HASH_SIZE 1
27#define ATOMIC_HASH(a) (&dummy)
28
29#endif /* SMP */
30
31#define ATOMIC_FETCH_OP(op, c_op) \
32int arch_atomic_fetch_##op(int i, atomic_t *v) \
33{ \
34 int ret; \
35 unsigned long flags; \
36 spin_lock_irqsave(ATOMIC_HASH(v), flags); \
37 \
38 ret = v->counter; \
39 v->counter c_op i; \
40 \
41 spin_unlock_irqrestore(ATOMIC_HASH(v), flags); \
42 return ret; \
43} \
44EXPORT_SYMBOL(arch_atomic_fetch_##op);
45
46#define ATOMIC_OP_RETURN(op, c_op) \
47int arch_atomic_##op##_return(int i, atomic_t *v) \
48{ \
49 int ret; \
50 unsigned long flags; \
51 spin_lock_irqsave(ATOMIC_HASH(v), flags); \
52 \
53 ret = (v->counter c_op i); \
54 \
55 spin_unlock_irqrestore(ATOMIC_HASH(v), flags); \
56 return ret; \
57} \
58EXPORT_SYMBOL(arch_atomic_##op##_return);
59
60ATOMIC_OP_RETURN(add, +=)
61
62ATOMIC_FETCH_OP(add, +=)
63ATOMIC_FETCH_OP(and, &=)
64ATOMIC_FETCH_OP(or, |=)
65ATOMIC_FETCH_OP(xor, ^=)
66
67#undef ATOMIC_FETCH_OP
68#undef ATOMIC_OP_RETURN
69
70int arch_atomic_xchg(atomic_t *v, int new)
71{
72 int ret;
73 unsigned long flags;
74
75 spin_lock_irqsave(ATOMIC_HASH(v), flags);
76 ret = v->counter;
77 v->counter = new;
78 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
79 return ret;
80}
81EXPORT_SYMBOL(arch_atomic_xchg);
82
83int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
84{
85 int ret;
86 unsigned long flags;
87
88 spin_lock_irqsave(ATOMIC_HASH(v), flags);
89 ret = v->counter;
90 if (likely(ret == old))
91 v->counter = new;
92
93 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
94 return ret;
95}
96EXPORT_SYMBOL(arch_atomic_cmpxchg);
97
98int arch_atomic_fetch_add_unless(atomic_t *v, int a, int u)
99{
100 int ret;
101 unsigned long flags;
102
103 spin_lock_irqsave(ATOMIC_HASH(v), flags);
104 ret = v->counter;
105 if (ret != u)
106 v->counter += a;
107 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
108 return ret;
109}
110EXPORT_SYMBOL(arch_atomic_fetch_add_unless);
111
112/* Atomic operations are already serializing */
113void arch_atomic_set(atomic_t *v, int i)
114{
115 unsigned long flags;
116
117 spin_lock_irqsave(ATOMIC_HASH(v), flags);
118 v->counter = i;
119 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
120}
121EXPORT_SYMBOL(arch_atomic_set);
122
123unsigned long sp32___set_bit(unsigned long *addr, unsigned long mask)
124{
125 unsigned long old, flags;
126
127 spin_lock_irqsave(ATOMIC_HASH(addr), flags);
128 old = *addr;
129 *addr = old | mask;
130 spin_unlock_irqrestore(ATOMIC_HASH(addr), flags);
131
132 return old & mask;
133}
134EXPORT_SYMBOL(sp32___set_bit);
135
136unsigned long sp32___clear_bit(unsigned long *addr, unsigned long mask)
137{
138 unsigned long old, flags;
139
140 spin_lock_irqsave(ATOMIC_HASH(addr), flags);
141 old = *addr;
142 *addr = old & ~mask;
143 spin_unlock_irqrestore(ATOMIC_HASH(addr), flags);
144
145 return old & mask;
146}
147EXPORT_SYMBOL(sp32___clear_bit);
148
149unsigned long sp32___change_bit(unsigned long *addr, unsigned long mask)
150{
151 unsigned long old, flags;
152
153 spin_lock_irqsave(ATOMIC_HASH(addr), flags);
154 old = *addr;
155 *addr = old ^ mask;
156 spin_unlock_irqrestore(ATOMIC_HASH(addr), flags);
157
158 return old & mask;
159}
160EXPORT_SYMBOL(sp32___change_bit);
161
162unsigned long __cmpxchg_u32(volatile u32 *ptr, u32 old, u32 new)
163{
164 unsigned long flags;
165 u32 prev;
166
167 spin_lock_irqsave(ATOMIC_HASH(ptr), flags);
168 if ((prev = *ptr) == old)
169 *ptr = new;
170 spin_unlock_irqrestore(ATOMIC_HASH(ptr), flags);
171
172 return (unsigned long)prev;
173}
174EXPORT_SYMBOL(__cmpxchg_u32);
175
176u64 __cmpxchg_u64(u64 *ptr, u64 old, u64 new)
177{
178 unsigned long flags;
179 u64 prev;
180
181 spin_lock_irqsave(ATOMIC_HASH(ptr), flags);
182 if ((prev = *ptr) == old)
183 *ptr = new;
184 spin_unlock_irqrestore(ATOMIC_HASH(ptr), flags);
185
186 return prev;
187}
188EXPORT_SYMBOL(__cmpxchg_u64);
189
190unsigned long __xchg_u32(volatile u32 *ptr, u32 new)
191{
192 unsigned long flags;
193 u32 prev;
194
195 spin_lock_irqsave(ATOMIC_HASH(ptr), flags);
196 prev = *ptr;
197 *ptr = new;
198 spin_unlock_irqrestore(ATOMIC_HASH(ptr), flags);
199
200 return (unsigned long)prev;
201}
202EXPORT_SYMBOL(__xchg_u32);
1/*
2 * atomic32.c: 32-bit atomic_t implementation
3 *
4 * Copyright (C) 2004 Keith M Wesolowski
5 * Copyright (C) 2007 Kyle McMartin
6 *
7 * Based on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf
8 */
9
10#include <linux/atomic.h>
11#include <linux/spinlock.h>
12#include <linux/module.h>
13
14#ifdef CONFIG_SMP
15#define ATOMIC_HASH_SIZE 4
16#define ATOMIC_HASH(a) (&__atomic_hash[(((unsigned long)a)>>8) & (ATOMIC_HASH_SIZE-1)])
17
18spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] = {
19 [0 ... (ATOMIC_HASH_SIZE-1)] = __SPIN_LOCK_UNLOCKED(__atomic_hash)
20};
21
22#else /* SMP */
23
24static DEFINE_SPINLOCK(dummy);
25#define ATOMIC_HASH_SIZE 1
26#define ATOMIC_HASH(a) (&dummy)
27
28#endif /* SMP */
29
30int __atomic_add_return(int i, atomic_t *v)
31{
32 int ret;
33 unsigned long flags;
34 spin_lock_irqsave(ATOMIC_HASH(v), flags);
35
36 ret = (v->counter += i);
37
38 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
39 return ret;
40}
41EXPORT_SYMBOL(__atomic_add_return);
42
43int atomic_cmpxchg(atomic_t *v, int old, int new)
44{
45 int ret;
46 unsigned long flags;
47
48 spin_lock_irqsave(ATOMIC_HASH(v), flags);
49 ret = v->counter;
50 if (likely(ret == old))
51 v->counter = new;
52
53 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
54 return ret;
55}
56EXPORT_SYMBOL(atomic_cmpxchg);
57
58int __atomic_add_unless(atomic_t *v, int a, int u)
59{
60 int ret;
61 unsigned long flags;
62
63 spin_lock_irqsave(ATOMIC_HASH(v), flags);
64 ret = v->counter;
65 if (ret != u)
66 v->counter += a;
67 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
68 return ret;
69}
70EXPORT_SYMBOL(__atomic_add_unless);
71
72/* Atomic operations are already serializing */
73void atomic_set(atomic_t *v, int i)
74{
75 unsigned long flags;
76
77 spin_lock_irqsave(ATOMIC_HASH(v), flags);
78 v->counter = i;
79 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
80}
81EXPORT_SYMBOL(atomic_set);
82
83unsigned long ___set_bit(unsigned long *addr, unsigned long mask)
84{
85 unsigned long old, flags;
86
87 spin_lock_irqsave(ATOMIC_HASH(addr), flags);
88 old = *addr;
89 *addr = old | mask;
90 spin_unlock_irqrestore(ATOMIC_HASH(addr), flags);
91
92 return old & mask;
93}
94EXPORT_SYMBOL(___set_bit);
95
96unsigned long ___clear_bit(unsigned long *addr, unsigned long mask)
97{
98 unsigned long old, flags;
99
100 spin_lock_irqsave(ATOMIC_HASH(addr), flags);
101 old = *addr;
102 *addr = old & ~mask;
103 spin_unlock_irqrestore(ATOMIC_HASH(addr), flags);
104
105 return old & mask;
106}
107EXPORT_SYMBOL(___clear_bit);
108
109unsigned long ___change_bit(unsigned long *addr, unsigned long mask)
110{
111 unsigned long old, flags;
112
113 spin_lock_irqsave(ATOMIC_HASH(addr), flags);
114 old = *addr;
115 *addr = old ^ mask;
116 spin_unlock_irqrestore(ATOMIC_HASH(addr), flags);
117
118 return old & mask;
119}
120EXPORT_SYMBOL(___change_bit);
121
122unsigned long __cmpxchg_u32(volatile u32 *ptr, u32 old, u32 new)
123{
124 unsigned long flags;
125 u32 prev;
126
127 spin_lock_irqsave(ATOMIC_HASH(ptr), flags);
128 if ((prev = *ptr) == old)
129 *ptr = new;
130 spin_unlock_irqrestore(ATOMIC_HASH(ptr), flags);
131
132 return (unsigned long)prev;
133}
134EXPORT_SYMBOL(__cmpxchg_u32);