1 #ifndef _ASM_X86_ATOMIC64_64_H
2 #define _ASM_X86_ATOMIC64_64_H
4 #include <linux/types.h>
5 #include <asm/alternative.h>
6 #include <asm/cmpxchg.h>
8 /* The 64-bit atomic type */
10 #define ATOMIC64_INIT(i) { (i) }
13 * atomic64_read - read atomic64 variable
14 * @v: pointer of type atomic64_t
16 * Atomically reads the value of @v.
17 * Doesn't imply a read memory barrier.
19 static inline long atomic64_read(const atomic64_t
*v
)
21 return READ_ONCE((v
)->counter
);
25 * atomic64_set - set atomic64 variable
26 * @v: pointer to type atomic64_t
29 * Atomically sets the value of @v to @i.
31 static inline void atomic64_set(atomic64_t
*v
, long i
)
33 WRITE_ONCE(v
->counter
, i
);
37 * atomic64_add - add integer to atomic64 variable
38 * @i: integer value to add
39 * @v: pointer to type atomic64_t
41 * Atomically adds @i to @v.
43 static __always_inline
void atomic64_add(long i
, atomic64_t
*v
)
45 asm volatile(LOCK_PREFIX
"addq %1,%0"
47 : "er" (i
), "m" (v
->counter
));
51 * atomic64_sub - subtract the atomic64 variable
52 * @i: integer value to subtract
53 * @v: pointer to type atomic64_t
55 * Atomically subtracts @i from @v.
57 static inline void atomic64_sub(long i
, atomic64_t
*v
)
59 asm volatile(LOCK_PREFIX
"subq %1,%0"
61 : "er" (i
), "m" (v
->counter
));
65 * atomic64_sub_and_test - subtract value from variable and test result
66 * @i: integer value to subtract
67 * @v: pointer to type atomic64_t
69 * Atomically subtracts @i from @v and returns
70 * true if the result is zero, or false for all
73 static inline bool atomic64_sub_and_test(long i
, atomic64_t
*v
)
75 GEN_BINARY_RMWcc(LOCK_PREFIX
"subq", v
->counter
, "er", i
, "%0", "e");
79 * atomic64_inc - increment atomic64 variable
80 * @v: pointer to type atomic64_t
82 * Atomically increments @v by 1.
84 static __always_inline
void atomic64_inc(atomic64_t
*v
)
86 asm volatile(LOCK_PREFIX
"incq %0"
92 * atomic64_dec - decrement atomic64 variable
93 * @v: pointer to type atomic64_t
95 * Atomically decrements @v by 1.
97 static __always_inline
void atomic64_dec(atomic64_t
*v
)
99 asm volatile(LOCK_PREFIX
"decq %0"
105 * atomic64_dec_and_test - decrement and test
106 * @v: pointer to type atomic64_t
108 * Atomically decrements @v by 1 and
109 * returns true if the result is 0, or false for all other
112 static inline bool atomic64_dec_and_test(atomic64_t
*v
)
114 GEN_UNARY_RMWcc(LOCK_PREFIX
"decq", v
->counter
, "%0", "e");
118 * atomic64_inc_and_test - increment and test
119 * @v: pointer to type atomic64_t
121 * Atomically increments @v by 1
122 * and returns true if the result is zero, or false for all
125 static inline bool atomic64_inc_and_test(atomic64_t
*v
)
127 GEN_UNARY_RMWcc(LOCK_PREFIX
"incq", v
->counter
, "%0", "e");
131 * atomic64_add_negative - add and test if negative
132 * @i: integer value to add
133 * @v: pointer to type atomic64_t
135 * Atomically adds @i to @v and returns true
136 * if the result is negative, or false when
137 * result is greater than or equal to zero.
139 static inline bool atomic64_add_negative(long i
, atomic64_t
*v
)
141 GEN_BINARY_RMWcc(LOCK_PREFIX
"addq", v
->counter
, "er", i
, "%0", "s");
145 * atomic64_add_return - add and return
146 * @i: integer value to add
147 * @v: pointer to type atomic64_t
149 * Atomically adds @i to @v and returns @i + @v
151 static __always_inline
long atomic64_add_return(long i
, atomic64_t
*v
)
153 return i
+ xadd(&v
->counter
, i
);
156 static inline long atomic64_sub_return(long i
, atomic64_t
*v
)
158 return atomic64_add_return(-i
, v
);
161 #define atomic64_inc_return(v) (atomic64_add_return(1, (v)))
162 #define atomic64_dec_return(v) (atomic64_sub_return(1, (v)))
164 static inline long atomic64_cmpxchg(atomic64_t
*v
, long old
, long new)
166 return cmpxchg(&v
->counter
, old
, new);
169 static inline long atomic64_xchg(atomic64_t
*v
, long new)
171 return xchg(&v
->counter
, new);
175 * atomic64_add_unless - add unless the number is a given value
176 * @v: pointer of type atomic64_t
177 * @a: the amount to add to v...
178 * @u: ...unless v is equal to u.
180 * Atomically adds @a to @v, so long as it was not @u.
181 * Returns the old value of @v.
183 static inline bool atomic64_add_unless(atomic64_t
*v
, long a
, long u
)
186 c
= atomic64_read(v
);
188 if (unlikely(c
== (u
)))
190 old
= atomic64_cmpxchg((v
), c
, c
+ (a
));
191 if (likely(old
== c
))
198 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
201 * atomic64_dec_if_positive - decrement by 1 if old value positive
202 * @v: pointer of type atomic_t
204 * The function returns the old value of *v minus 1, even if
205 * the atomic variable, v, was not decremented.
207 static inline long atomic64_dec_if_positive(atomic64_t
*v
)
210 c
= atomic64_read(v
);
213 if (unlikely(dec
< 0))
215 old
= atomic64_cmpxchg((v
), c
, dec
);
216 if (likely(old
== c
))
223 #define ATOMIC64_OP(op) \
224 static inline void atomic64_##op(long i, atomic64_t *v) \
226 asm volatile(LOCK_PREFIX #op"q %1,%0" \
227 : "+m" (v->counter) \
238 #endif /* _ASM_X86_ATOMIC64_64_H */
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