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
|
#ifndef _ASM_X86_ATOMIC64_64_H
#define _ASM_X86_ATOMIC64_64_H
#include <linux/types.h>
#include <asm/alternative.h>
#include <asm/cmpxchg.h>
/* The 64-bit atomic type */
#define ATOMIC64_INIT(i) { (i) }
/**
* atomic64_read - read atomic64 variable
* @v: pointer of type atomic64_t
*
* Atomically reads the value of @v.
* Doesn't imply a read memory barrier.
*/
static inline long atomic64_read(const atomic64_t *v)
{
return ACCESS_ONCE((v)->counter);
}
/**
* atomic64_set - set atomic64 variable
* @v: pointer to type atomic64_t
* @i: required value
*
* Atomically sets the value of @v to @i.
*/
static inline void atomic64_set(atomic64_t *v, long i)
{
v->counter = i;
}
/**
* atomic64_add - add integer to atomic64 variable
* @i: integer value to add
* @v: pointer to type atomic64_t
*
* Atomically adds @i to @v.
*/
static __always_inline void atomic64_add(long i, atomic64_t *v)
{
asm volatile(LOCK_PREFIX "addq %1,%0"
: "=m" (v->counter)
: "er" (i), "m" (v->counter));
}
/**
* atomic64_sub - subtract the atomic64 variable
* @i: integer value to subtract
* @v: pointer to type atomic64_t
*
* Atomically subtracts @i from @v.
*/
static inline void atomic64_sub(long i, atomic64_t *v)
{
asm volatile(LOCK_PREFIX "subq %1,%0"
: "=m" (v->counter)
: "er" (i), "m" (v->counter));
}
/**
* atomic64_sub_and_test - subtract value from variable and test result
* @i: integer value to subtract
* @v: pointer to type atomic64_t
*
* Atomically subtracts @i from @v and returns
* true if the result is zero, or false for all
* other cases.
*/
static inline int atomic64_sub_and_test(long i, atomic64_t *v)
{
GEN_BINARY_RMWcc(LOCK_PREFIX "subq", v->counter, "er", i, "%0", "e");
}
/**
* atomic64_inc - increment atomic64 variable
* @v: pointer to type atomic64_t
*
* Atomically increments @v by 1.
*/
static __always_inline void atomic64_inc(atomic64_t *v)
{
asm volatile(LOCK_PREFIX "incq %0"
: "=m" (v->counter)
: "m" (v->counter));
}
/**
* atomic64_dec - decrement atomic64 variable
* @v: pointer to type atomic64_t
*
* Atomically decrements @v by 1.
*/
static __always_inline void atomic64_dec(atomic64_t *v)
{
asm volatile(LOCK_PREFIX "decq %0"
: "=m" (v->counter)
: "m" (v->counter));
}
/**
* atomic64_dec_and_test - decrement and test
* @v: pointer to type atomic64_t
*
* Atomically decrements @v by 1 and
* returns true if the result is 0, or false for all other
* cases.
*/
static inline int atomic64_dec_and_test(atomic64_t *v)
{
GEN_UNARY_RMWcc(LOCK_PREFIX "decq", v->counter, "%0", "e");
}
/**
* atomic64_inc_and_test - increment and test
* @v: pointer to type atomic64_t
*
* Atomically increments @v by 1
* and returns true if the result is zero, or false for all
* other cases.
*/
static inline int atomic64_inc_and_test(atomic64_t *v)
{
GEN_UNARY_RMWcc(LOCK_PREFIX "incq", v->counter, "%0", "e");
}
/**
* atomic64_add_negative - add and test if negative
* @i: integer value to add
* @v: pointer to type atomic64_t
*
* Atomically adds @i to @v and returns true
* if the result is negative, or false when
* result is greater than or equal to zero.
*/
static inline int atomic64_add_negative(long i, atomic64_t *v)
{
GEN_BINARY_RMWcc(LOCK_PREFIX "addq", v->counter, "er", i, "%0", "s");
}
/**
* atomic64_add_return - add and return
* @i: integer value to add
* @v: pointer to type atomic64_t
*
* Atomically adds @i to @v and returns @i + @v
*/
static __always_inline long atomic64_add_return(long i, atomic64_t *v)
{
return i + xadd(&v->counter, i);
}
static inline long atomic64_sub_return(long i, atomic64_t *v)
{
return atomic64_add_return(-i, v);
}
#define atomic64_inc_return(v) (atomic64_add_return(1, (v)))
#define atomic64_dec_return(v) (atomic64_sub_return(1, (v)))
static inline long atomic64_cmpxchg(atomic64_t *v, long old, long new)
{
return cmpxchg(&v->counter, old, new);
}
static inline long atomic64_xchg(atomic64_t *v, long new)
{
return xchg(&v->counter, new);
}
/**
* atomic64_add_unless - add unless the number is a given value
* @v: pointer of type atomic64_t
* @a: the amount to add to v...
* @u: ...unless v is equal to u.
*
* Atomically adds @a to @v, so long as it was not @u.
* Returns the old value of @v.
*/
static inline int atomic64_add_unless(atomic64_t *v, long a, long u)
{
long c, old;
c = atomic64_read(v);
for (;;) {
if (unlikely(c == (u)))
break;
old = atomic64_cmpxchg((v), c, c + (a));
if (likely(old == c))
break;
c = old;
}
return c != (u);
}
#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
/*
* 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;
}
#define ATOMIC64_OP(op) \
static inline void atomic64_##op(long i, atomic64_t *v) \
{ \
asm volatile(LOCK_PREFIX #op"q %1,%0" \
: "+m" (v->counter) \
: "er" (i) \
: "memory"); \
}
ATOMIC64_OP(and)
ATOMIC64_OP(or)
ATOMIC64_OP(xor)
#undef ATOMIC64_OP
#endif /* _ASM_X86_ATOMIC64_64_H */
|
