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 int 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 int 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 int 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 int 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 int 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 */