1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
|
/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
* Copyright (C) 2006 Kyle McMartin <kyle@parisc-linux.org>
*/
#ifndef _ASM_PARISC_ATOMIC_H_
#define _ASM_PARISC_ATOMIC_H_
#include <linux/types.h>
#include <asm/cmpxchg.h>
#include <asm/barrier.h>
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
*
* And probably incredibly slow on parisc. OTOH, we don't
* have to write any serious assembly. prumpf
*/
#ifdef CONFIG_SMP
#include <asm/spinlock.h>
#include <asm/cache.h> /* we use L1_CACHE_BYTES */
/* Use an array of spinlocks for our atomic_ts.
* Hash function to index into a different SPINLOCK.
* Since "a" is usually an address, use one spinlock per cacheline.
*/
# define ATOMIC_HASH_SIZE 4
# define ATOMIC_HASH(a) (&(__atomic_hash[ (((unsigned long) (a))/L1_CACHE_BYTES) & (ATOMIC_HASH_SIZE-1) ]))
extern arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned;
/* Can't use raw_spin_lock_irq because of #include problems, so
* this is the substitute */
#define _atomic_spin_lock_irqsave(l,f) do { \
arch_spinlock_t *s = ATOMIC_HASH(l); \
local_irq_save(f); \
arch_spin_lock(s); \
} while(0)
#define _atomic_spin_unlock_irqrestore(l,f) do { \
arch_spinlock_t *s = ATOMIC_HASH(l); \
arch_spin_unlock(s); \
local_irq_restore(f); \
} while(0)
#else
# define _atomic_spin_lock_irqsave(l,f) do { local_irq_save(f); } while (0)
# define _atomic_spin_unlock_irqrestore(l,f) do { local_irq_restore(f); } while (0)
#endif
/*
* Note that we need not lock read accesses - aligned word writes/reads
* are atomic, so a reader never sees inconsistent values.
*/
static __inline__ void atomic_set(atomic_t *v, int i)
{
unsigned long flags;
_atomic_spin_lock_irqsave(v, flags);
v->counter = i;
_atomic_spin_unlock_irqrestore(v, flags);
}
#define atomic_set_release(v, i) atomic_set((v), (i))
static __inline__ int atomic_read(const atomic_t *v)
{
return READ_ONCE((v)->counter);
}
/* exported interface */
#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
#define ATOMIC_OP(op, c_op) \
static __inline__ void atomic_##op(int i, atomic_t *v) \
{ \
unsigned long flags; \
\
_atomic_spin_lock_irqsave(v, flags); \
v->counter c_op i; \
_atomic_spin_unlock_irqrestore(v, flags); \
} \
#define ATOMIC_OP_RETURN(op, c_op) \
static __inline__ int atomic_##op##_return(int i, atomic_t *v) \
{ \
unsigned long flags; \
int ret; \
\
_atomic_spin_lock_irqsave(v, flags); \
ret = (v->counter c_op i); \
_atomic_spin_unlock_irqrestore(v, flags); \
\
return ret; \
}
#define ATOMIC_FETCH_OP(op, c_op) \
static __inline__ int atomic_fetch_##op(int i, atomic_t *v) \
{ \
unsigned long flags; \
int ret; \
\
_atomic_spin_lock_irqsave(v, flags); \
ret = v->counter; \
v->counter c_op i; \
_atomic_spin_unlock_irqrestore(v, flags); \
\
return ret; \
}
#define ATOMIC_OPS(op, c_op) \
ATOMIC_OP(op, c_op) \
ATOMIC_OP_RETURN(op, c_op) \
ATOMIC_FETCH_OP(op, c_op)
ATOMIC_OPS(add, +=)
ATOMIC_OPS(sub, -=)
#undef ATOMIC_OPS
#define ATOMIC_OPS(op, c_op) \
ATOMIC_OP(op, c_op) \
ATOMIC_FETCH_OP(op, c_op)
ATOMIC_OPS(and, &=)
ATOMIC_OPS(or, |=)
ATOMIC_OPS(xor, ^=)
#undef ATOMIC_OPS
#undef ATOMIC_FETCH_OP
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
#define ATOMIC_INIT(i) { (i) }
#ifdef CONFIG_64BIT
#define ATOMIC64_INIT(i) { (i) }
#define ATOMIC64_OP(op, c_op) \
static __inline__ void atomic64_##op(s64 i, atomic64_t *v) \
{ \
unsigned long flags; \
\
_atomic_spin_lock_irqsave(v, flags); \
v->counter c_op i; \
_atomic_spin_unlock_irqrestore(v, flags); \
} \
#define ATOMIC64_OP_RETURN(op, c_op) \
static __inline__ s64 atomic64_##op##_return(s64 i, atomic64_t *v) \
{ \
unsigned long flags; \
s64 ret; \
\
_atomic_spin_lock_irqsave(v, flags); \
ret = (v->counter c_op i); \
_atomic_spin_unlock_irqrestore(v, flags); \
\
return ret; \
}
#define ATOMIC64_FETCH_OP(op, c_op) \
static __inline__ s64 atomic64_fetch_##op(s64 i, atomic64_t *v) \
{ \
unsigned long flags; \
s64 ret; \
\
_atomic_spin_lock_irqsave(v, flags); \
ret = v->counter; \
v->counter c_op i; \
_atomic_spin_unlock_irqrestore(v, flags); \
\
return ret; \
}
#define ATOMIC64_OPS(op, c_op) \
ATOMIC64_OP(op, c_op) \
ATOMIC64_OP_RETURN(op, c_op) \
ATOMIC64_FETCH_OP(op, c_op)
ATOMIC64_OPS(add, +=)
ATOMIC64_OPS(sub, -=)
#undef ATOMIC64_OPS
#define ATOMIC64_OPS(op, c_op) \
ATOMIC64_OP(op, c_op) \
ATOMIC64_FETCH_OP(op, c_op)
ATOMIC64_OPS(and, &=)
ATOMIC64_OPS(or, |=)
ATOMIC64_OPS(xor, ^=)
#undef ATOMIC64_OPS
#undef ATOMIC64_FETCH_OP
#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP
static __inline__ void
atomic64_set(atomic64_t *v, s64 i)
{
unsigned long flags;
_atomic_spin_lock_irqsave(v, flags);
v->counter = i;
_atomic_spin_unlock_irqrestore(v, flags);
}
static __inline__ s64
atomic64_read(const atomic64_t *v)
{
return READ_ONCE((v)->counter);
}
/* exported interface */
#define atomic64_cmpxchg(v, o, n) \
((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
/*
* atomic64_dec_if_positive - decrement by 1 if old value positive
* @v: pointer of type atomic_t
*
* The function returns the old value of *v minus 1, even if
* the atomic variable, v, was not decremented.
*/
static inline long atomic64_dec_if_positive(atomic64_t *v)
{
long c, old, dec;
c = atomic64_read(v);
for (;;) {
dec = c - 1;
if (unlikely(dec < 0))
break;
old = atomic64_cmpxchg((v), c, dec);
if (likely(old == c))
break;
c = old;
}
return dec;
}
#endif /* !CONFIG_64BIT */
#endif /* _ASM_PARISC_ATOMIC_H_ */
|
