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 (*(volatile long *)&(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)
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 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)
77 asm volatile(LOCK_PREFIX "subq %2,%0; sete %1"
78 : "=m" (v->counter), "=qm" (c)
79 : "er" (i), "m" (v->counter) : "memory");
84 * atomic64_inc - increment atomic64 variable
85 * @v: pointer to type atomic64_t
87 * Atomically increments @v by 1.
89 static inline void atomic64_inc(atomic64_t *v)
91 asm volatile(LOCK_PREFIX "incq %0"
97 * atomic64_dec - decrement atomic64 variable
98 * @v: pointer to type atomic64_t
100 * Atomically decrements @v by 1.
102 static inline void atomic64_dec(atomic64_t *v)
104 asm volatile(LOCK_PREFIX "decq %0"
110 * atomic64_dec_and_test - decrement and test
111 * @v: pointer to type atomic64_t
113 * Atomically decrements @v by 1 and
114 * returns true if the result is 0, or false for all other
117 static inline int atomic64_dec_and_test(atomic64_t *v)
121 asm volatile(LOCK_PREFIX "decq %0; sete %1"
122 : "=m" (v->counter), "=qm" (c)
123 : "m" (v->counter) : "memory");
128 * atomic64_inc_and_test - increment and test
129 * @v: pointer to type atomic64_t
131 * Atomically increments @v by 1
132 * and returns true if the result is zero, or false for all
135 static inline int atomic64_inc_and_test(atomic64_t *v)
139 asm volatile(LOCK_PREFIX "incq %0; sete %1"
140 : "=m" (v->counter), "=qm" (c)
141 : "m" (v->counter) : "memory");
146 * atomic64_add_negative - add and test if negative
147 * @i: integer value to add
148 * @v: pointer to type atomic64_t
150 * Atomically adds @i to @v and returns true
151 * if the result is negative, or false when
152 * result is greater than or equal to zero.
154 static inline int atomic64_add_negative(long i, atomic64_t *v)
158 asm volatile(LOCK_PREFIX "addq %2,%0; sets %1"
159 : "=m" (v->counter), "=qm" (c)
160 : "er" (i), "m" (v->counter) : "memory");
165 * atomic64_add_return - add and return
166 * @i: integer value to add
167 * @v: pointer to type atomic64_t
169 * Atomically adds @i to @v and returns @i + @v
171 static inline long atomic64_add_return(long i, atomic64_t *v)
174 asm volatile(LOCK_PREFIX "xaddq %0, %1;"
175 : "+r" (i), "+m" (v->counter)
180 static inline long atomic64_sub_return(long i, atomic64_t *v)
182 return atomic64_add_return(-i, v);
185 #define atomic64_inc_return(v) (atomic64_add_return(1, (v)))
186 #define atomic64_dec_return(v) (atomic64_sub_return(1, (v)))
188 static inline long atomic64_cmpxchg(atomic64_t *v, long old, long new)
190 return cmpxchg(&v->counter, old, new);
193 static inline long atomic64_xchg(atomic64_t *v, long new)
195 return xchg(&v->counter, new);
199 * atomic64_add_unless - add unless the number is a given value
200 * @v: pointer of type atomic64_t
201 * @a: the amount to add to v...
202 * @u: ...unless v is equal to u.
204 * Atomically adds @a to @v, so long as it was not @u.
205 * Returns non-zero if @v was not @u, and zero otherwise.
207 static inline int atomic64_add_unless(atomic64_t *v, long a, long u)
210 c = atomic64_read(v);
212 if (unlikely(c == (u)))
214 old = atomic64_cmpxchg((v), c, c + (a));
215 if (likely(old == c))
222 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
225 * atomic64_dec_if_positive - decrement by 1 if old value positive
226 * @v: pointer of type atomic_t
228 * The function returns the old value of *v minus 1, even if
229 * the atomic variable, v, was not decremented.
231 static inline long atomic64_dec_if_positive(atomic64_t *v)
234 c = atomic64_read(v);
237 if (unlikely(dec < 0))
239 old = atomic64_cmpxchg((v), c, dec);
240 if (likely(old == c))
247 #endif /* _ASM_X86_ATOMIC64_64_H */