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1 | #ifndef _ASM_X86_ATOMIC64_64_H |
2 | #define _ASM_X86_ATOMIC64_64_H | |
3 | ||
4 | #include <linux/types.h> | |
5 | #include <asm/alternative.h> | |
6 | #include <asm/cmpxchg.h> | |
7 | ||
8 | /* The 64-bit atomic type */ | |
9 | ||
10 | #define ATOMIC64_INIT(i) { (i) } | |
11 | ||
12 | /** | |
13 | * atomic64_read - read atomic64 variable | |
14 | * @v: pointer of type atomic64_t | |
15 | * | |
16 | * Atomically reads the value of @v. | |
17 | * Doesn't imply a read memory barrier. | |
18 | */ | |
19 | static inline long atomic64_read(const atomic64_t *v) | |
20 | { | |
f3d46f9d | 21 | return (*(volatile long *)&(v)->counter); |
1a3b1d89 BG |
22 | } |
23 | ||
24 | /** | |
25 | * atomic64_set - set atomic64 variable | |
26 | * @v: pointer to type atomic64_t | |
27 | * @i: required value | |
28 | * | |
29 | * Atomically sets the value of @v to @i. | |
30 | */ | |
31 | static inline void atomic64_set(atomic64_t *v, long i) | |
32 | { | |
33 | v->counter = i; | |
34 | } | |
35 | ||
36 | /** | |
37 | * atomic64_add - add integer to atomic64 variable | |
38 | * @i: integer value to add | |
39 | * @v: pointer to type atomic64_t | |
40 | * | |
41 | * Atomically adds @i to @v. | |
42 | */ | |
43 | static inline void atomic64_add(long i, atomic64_t *v) | |
44 | { | |
45 | asm volatile(LOCK_PREFIX "addq %1,%0" | |
46 | : "=m" (v->counter) | |
47 | : "er" (i), "m" (v->counter)); | |
48 | } | |
49 | ||
50 | /** | |
51 | * atomic64_sub - subtract the atomic64 variable | |
52 | * @i: integer value to subtract | |
53 | * @v: pointer to type atomic64_t | |
54 | * | |
55 | * Atomically subtracts @i from @v. | |
56 | */ | |
57 | static inline void atomic64_sub(long i, atomic64_t *v) | |
58 | { | |
59 | asm volatile(LOCK_PREFIX "subq %1,%0" | |
60 | : "=m" (v->counter) | |
61 | : "er" (i), "m" (v->counter)); | |
62 | } | |
63 | ||
64 | /** | |
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 | |
68 | * | |
69 | * Atomically subtracts @i from @v and returns | |
70 | * true if the result is zero, or false for all | |
71 | * other cases. | |
72 | */ | |
73 | static inline int atomic64_sub_and_test(long i, atomic64_t *v) | |
74 | { | |
75 | unsigned char c; | |
76 | ||
77 | asm volatile(LOCK_PREFIX "subq %2,%0; sete %1" | |
78 | : "=m" (v->counter), "=qm" (c) | |
79 | : "er" (i), "m" (v->counter) : "memory"); | |
80 | return c; | |
81 | } | |
82 | ||
83 | /** | |
84 | * atomic64_inc - increment atomic64 variable | |
85 | * @v: pointer to type atomic64_t | |
86 | * | |
87 | * Atomically increments @v by 1. | |
88 | */ | |
89 | static inline void atomic64_inc(atomic64_t *v) | |
90 | { | |
91 | asm volatile(LOCK_PREFIX "incq %0" | |
92 | : "=m" (v->counter) | |
93 | : "m" (v->counter)); | |
94 | } | |
95 | ||
96 | /** | |
97 | * atomic64_dec - decrement atomic64 variable | |
98 | * @v: pointer to type atomic64_t | |
99 | * | |
100 | * Atomically decrements @v by 1. | |
101 | */ | |
102 | static inline void atomic64_dec(atomic64_t *v) | |
103 | { | |
104 | asm volatile(LOCK_PREFIX "decq %0" | |
105 | : "=m" (v->counter) | |
106 | : "m" (v->counter)); | |
107 | } | |
108 | ||
109 | /** | |
110 | * atomic64_dec_and_test - decrement and test | |
111 | * @v: pointer to type atomic64_t | |
112 | * | |
113 | * Atomically decrements @v by 1 and | |
114 | * returns true if the result is 0, or false for all other | |
115 | * cases. | |
116 | */ | |
117 | static inline int atomic64_dec_and_test(atomic64_t *v) | |
118 | { | |
119 | unsigned char c; | |
120 | ||
121 | asm volatile(LOCK_PREFIX "decq %0; sete %1" | |
122 | : "=m" (v->counter), "=qm" (c) | |
123 | : "m" (v->counter) : "memory"); | |
124 | return c != 0; | |
125 | } | |
126 | ||
127 | /** | |
128 | * atomic64_inc_and_test - increment and test | |
129 | * @v: pointer to type atomic64_t | |
130 | * | |
131 | * Atomically increments @v by 1 | |
132 | * and returns true if the result is zero, or false for all | |
133 | * other cases. | |
134 | */ | |
135 | static inline int atomic64_inc_and_test(atomic64_t *v) | |
136 | { | |
137 | unsigned char c; | |
138 | ||
139 | asm volatile(LOCK_PREFIX "incq %0; sete %1" | |
140 | : "=m" (v->counter), "=qm" (c) | |
141 | : "m" (v->counter) : "memory"); | |
142 | return c != 0; | |
143 | } | |
144 | ||
145 | /** | |
146 | * atomic64_add_negative - add and test if negative | |
147 | * @i: integer value to add | |
148 | * @v: pointer to type atomic64_t | |
149 | * | |
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. | |
153 | */ | |
154 | static inline int atomic64_add_negative(long i, atomic64_t *v) | |
155 | { | |
156 | unsigned char c; | |
157 | ||
158 | asm volatile(LOCK_PREFIX "addq %2,%0; sets %1" | |
159 | : "=m" (v->counter), "=qm" (c) | |
160 | : "er" (i), "m" (v->counter) : "memory"); | |
161 | return c; | |
162 | } | |
163 | ||
164 | /** | |
165 | * atomic64_add_return - add and return | |
166 | * @i: integer value to add | |
167 | * @v: pointer to type atomic64_t | |
168 | * | |
169 | * Atomically adds @i to @v and returns @i + @v | |
170 | */ | |
171 | static inline long atomic64_add_return(long i, atomic64_t *v) | |
172 | { | |
8b8bc2f7 | 173 | return i + xadd(&v->counter, i); |
1a3b1d89 BG |
174 | } |
175 | ||
176 | static inline long atomic64_sub_return(long i, atomic64_t *v) | |
177 | { | |
178 | return atomic64_add_return(-i, v); | |
179 | } | |
180 | ||
181 | #define atomic64_inc_return(v) (atomic64_add_return(1, (v))) | |
182 | #define atomic64_dec_return(v) (atomic64_sub_return(1, (v))) | |
183 | ||
184 | static inline long atomic64_cmpxchg(atomic64_t *v, long old, long new) | |
185 | { | |
186 | return cmpxchg(&v->counter, old, new); | |
187 | } | |
188 | ||
189 | static inline long atomic64_xchg(atomic64_t *v, long new) | |
190 | { | |
191 | return xchg(&v->counter, new); | |
192 | } | |
193 | ||
194 | /** | |
195 | * atomic64_add_unless - add unless the number is a given value | |
196 | * @v: pointer of type atomic64_t | |
197 | * @a: the amount to add to v... | |
198 | * @u: ...unless v is equal to u. | |
199 | * | |
200 | * Atomically adds @a to @v, so long as it was not @u. | |
f24219b4 | 201 | * Returns the old value of @v. |
1a3b1d89 BG |
202 | */ |
203 | static inline int atomic64_add_unless(atomic64_t *v, long a, long u) | |
204 | { | |
205 | long c, old; | |
206 | c = atomic64_read(v); | |
207 | for (;;) { | |
208 | if (unlikely(c == (u))) | |
209 | break; | |
210 | old = atomic64_cmpxchg((v), c, c + (a)); | |
211 | if (likely(old == c)) | |
212 | break; | |
213 | c = old; | |
214 | } | |
215 | return c != (u); | |
216 | } | |
217 | ||
218 | #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) | |
219 | ||
d7f6de1e LB |
220 | /* |
221 | * atomic64_dec_if_positive - decrement by 1 if old value positive | |
222 | * @v: pointer of type atomic_t | |
223 | * | |
224 | * The function returns the old value of *v minus 1, even if | |
225 | * the atomic variable, v, was not decremented. | |
226 | */ | |
227 | static inline long atomic64_dec_if_positive(atomic64_t *v) | |
228 | { | |
229 | long c, old, dec; | |
230 | c = atomic64_read(v); | |
231 | for (;;) { | |
232 | dec = c - 1; | |
233 | if (unlikely(dec < 0)) | |
234 | break; | |
235 | old = atomic64_cmpxchg((v), c, dec); | |
236 | if (likely(old == c)) | |
237 | break; | |
238 | c = old; | |
239 | } | |
240 | return dec; | |
241 | } | |
242 | ||
1a3b1d89 | 243 | #endif /* _ASM_X86_ATOMIC64_64_H */ |