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1 | #ifndef _ASM_X86_ATOMIC_H |
2 | #define _ASM_X86_ATOMIC_H | |
3 | ||
4 | #include <linux/compiler.h> | |
5 | #include <linux/types.h> | |
6 | #include <asm/processor.h> | |
7 | #include <asm/alternative.h> | |
8 | #include <asm/cmpxchg.h> | |
0c44c2d0 | 9 | #include <asm/rmwcc.h> |
5abbbbf0 BG |
10 | |
11 | /* | |
12 | * Atomic operations that C can't guarantee us. Useful for | |
13 | * resource counting etc.. | |
14 | */ | |
15 | ||
16 | #define ATOMIC_INIT(i) { (i) } | |
17 | ||
18 | /** | |
19 | * atomic_read - read atomic variable | |
20 | * @v: pointer of type atomic_t | |
21 | * | |
22 | * Atomically reads the value of @v. | |
23 | */ | |
24 | static inline int atomic_read(const atomic_t *v) | |
25 | { | |
f3d46f9d | 26 | return (*(volatile int *)&(v)->counter); |
5abbbbf0 BG |
27 | } |
28 | ||
29 | /** | |
30 | * atomic_set - set atomic variable | |
31 | * @v: pointer of type atomic_t | |
32 | * @i: required value | |
33 | * | |
34 | * Atomically sets the value of @v to @i. | |
35 | */ | |
36 | static inline void atomic_set(atomic_t *v, int i) | |
37 | { | |
38 | v->counter = i; | |
39 | } | |
40 | ||
41 | /** | |
42 | * atomic_add - add integer to atomic variable | |
43 | * @i: integer value to add | |
44 | * @v: pointer of type atomic_t | |
45 | * | |
46 | * Atomically adds @i to @v. | |
47 | */ | |
48 | static inline void atomic_add(int i, atomic_t *v) | |
49 | { | |
50 | asm volatile(LOCK_PREFIX "addl %1,%0" | |
51 | : "+m" (v->counter) | |
52 | : "ir" (i)); | |
53 | } | |
54 | ||
55 | /** | |
56 | * atomic_sub - subtract integer from atomic variable | |
57 | * @i: integer value to subtract | |
58 | * @v: pointer of type atomic_t | |
59 | * | |
60 | * Atomically subtracts @i from @v. | |
61 | */ | |
62 | static inline void atomic_sub(int i, atomic_t *v) | |
63 | { | |
64 | asm volatile(LOCK_PREFIX "subl %1,%0" | |
65 | : "+m" (v->counter) | |
66 | : "ir" (i)); | |
67 | } | |
68 | ||
69 | /** | |
70 | * atomic_sub_and_test - subtract value from variable and test result | |
71 | * @i: integer value to subtract | |
72 | * @v: pointer of type atomic_t | |
73 | * | |
74 | * Atomically subtracts @i from @v and returns | |
75 | * true if the result is zero, or false for all | |
76 | * other cases. | |
77 | */ | |
78 | static inline int atomic_sub_and_test(int i, atomic_t *v) | |
79 | { | |
e0f6dec3 | 80 | GEN_BINARY_RMWcc(LOCK_PREFIX "subl", v->counter, "er", i, "%0", "e"); |
5abbbbf0 BG |
81 | } |
82 | ||
83 | /** | |
84 | * atomic_inc - increment atomic variable | |
85 | * @v: pointer of type atomic_t | |
86 | * | |
87 | * Atomically increments @v by 1. | |
88 | */ | |
89 | static inline void atomic_inc(atomic_t *v) | |
90 | { | |
91 | asm volatile(LOCK_PREFIX "incl %0" | |
92 | : "+m" (v->counter)); | |
93 | } | |
94 | ||
95 | /** | |
96 | * atomic_dec - decrement atomic variable | |
97 | * @v: pointer of type atomic_t | |
98 | * | |
99 | * Atomically decrements @v by 1. | |
100 | */ | |
101 | static inline void atomic_dec(atomic_t *v) | |
102 | { | |
103 | asm volatile(LOCK_PREFIX "decl %0" | |
104 | : "+m" (v->counter)); | |
105 | } | |
106 | ||
107 | /** | |
108 | * atomic_dec_and_test - decrement and test | |
109 | * @v: pointer of type atomic_t | |
110 | * | |
111 | * Atomically decrements @v by 1 and | |
112 | * returns true if the result is 0, or false for all other | |
113 | * cases. | |
114 | */ | |
115 | static inline int atomic_dec_and_test(atomic_t *v) | |
116 | { | |
0c44c2d0 | 117 | GEN_UNARY_RMWcc(LOCK_PREFIX "decl", v->counter, "%0", "e"); |
5abbbbf0 BG |
118 | } |
119 | ||
120 | /** | |
121 | * atomic_inc_and_test - increment and test | |
122 | * @v: pointer of type atomic_t | |
123 | * | |
124 | * Atomically increments @v by 1 | |
125 | * and returns true if the result is zero, or false for all | |
126 | * other cases. | |
127 | */ | |
128 | static inline int atomic_inc_and_test(atomic_t *v) | |
129 | { | |
0c44c2d0 | 130 | GEN_UNARY_RMWcc(LOCK_PREFIX "incl", v->counter, "%0", "e"); |
5abbbbf0 BG |
131 | } |
132 | ||
133 | /** | |
134 | * atomic_add_negative - add and test if negative | |
135 | * @i: integer value to add | |
136 | * @v: pointer of type atomic_t | |
137 | * | |
138 | * Atomically adds @i to @v and returns true | |
139 | * if the result is negative, or false when | |
140 | * result is greater than or equal to zero. | |
141 | */ | |
142 | static inline int atomic_add_negative(int i, atomic_t *v) | |
143 | { | |
e0f6dec3 | 144 | GEN_BINARY_RMWcc(LOCK_PREFIX "addl", v->counter, "er", i, "%0", "s"); |
5abbbbf0 BG |
145 | } |
146 | ||
147 | /** | |
148 | * atomic_add_return - add integer and return | |
149 | * @i: integer value to add | |
150 | * @v: pointer of type atomic_t | |
151 | * | |
152 | * Atomically adds @i to @v and returns @i + @v | |
153 | */ | |
154 | static inline int atomic_add_return(int i, atomic_t *v) | |
155 | { | |
8b8bc2f7 | 156 | return i + xadd(&v->counter, i); |
5abbbbf0 BG |
157 | } |
158 | ||
159 | /** | |
160 | * atomic_sub_return - subtract integer and return | |
161 | * @v: pointer of type atomic_t | |
162 | * @i: integer value to subtract | |
163 | * | |
164 | * Atomically subtracts @i from @v and returns @v - @i | |
165 | */ | |
166 | static inline int atomic_sub_return(int i, atomic_t *v) | |
167 | { | |
168 | return atomic_add_return(-i, v); | |
169 | } | |
170 | ||
171 | #define atomic_inc_return(v) (atomic_add_return(1, v)) | |
172 | #define atomic_dec_return(v) (atomic_sub_return(1, v)) | |
173 | ||
174 | static inline int atomic_cmpxchg(atomic_t *v, int old, int new) | |
175 | { | |
176 | return cmpxchg(&v->counter, old, new); | |
177 | } | |
178 | ||
179 | static inline int atomic_xchg(atomic_t *v, int new) | |
180 | { | |
181 | return xchg(&v->counter, new); | |
182 | } | |
183 | ||
184 | /** | |
f24219b4 | 185 | * __atomic_add_unless - add unless the number is already a given value |
5abbbbf0 BG |
186 | * @v: pointer of type atomic_t |
187 | * @a: the amount to add to v... | |
188 | * @u: ...unless v is equal to u. | |
189 | * | |
190 | * Atomically adds @a to @v, so long as @v was not already @u. | |
f24219b4 | 191 | * Returns the old value of @v. |
5abbbbf0 | 192 | */ |
f24219b4 | 193 | static inline int __atomic_add_unless(atomic_t *v, int a, int u) |
5abbbbf0 BG |
194 | { |
195 | int c, old; | |
196 | c = atomic_read(v); | |
197 | for (;;) { | |
198 | if (unlikely(c == (u))) | |
199 | break; | |
200 | old = atomic_cmpxchg((v), c, c + (a)); | |
201 | if (likely(old == c)) | |
202 | break; | |
203 | c = old; | |
204 | } | |
f24219b4 | 205 | return c; |
5abbbbf0 BG |
206 | } |
207 | ||
5abbbbf0 BG |
208 | /** |
209 | * atomic_inc_short - increment of a short integer | |
210 | * @v: pointer to type int | |
211 | * | |
212 | * Atomically adds 1 to @v | |
213 | * Returns the new value of @u | |
214 | */ | |
215 | static inline short int atomic_inc_short(short int *v) | |
216 | { | |
217 | asm(LOCK_PREFIX "addw $1, %0" : "+m" (*v)); | |
218 | return *v; | |
219 | } | |
220 | ||
221 | #ifdef CONFIG_X86_64 | |
222 | /** | |
223 | * atomic_or_long - OR of two long integers | |
224 | * @v1: pointer to type unsigned long | |
225 | * @v2: pointer to type unsigned long | |
226 | * | |
227 | * Atomically ORs @v1 and @v2 | |
228 | * Returns the result of the OR | |
229 | */ | |
230 | static inline void atomic_or_long(unsigned long *v1, unsigned long v2) | |
231 | { | |
232 | asm(LOCK_PREFIX "orq %1, %0" : "+m" (*v1) : "r" (v2)); | |
233 | } | |
234 | #endif | |
235 | ||
236 | /* These are x86-specific, used by some header files */ | |
237 | #define atomic_clear_mask(mask, addr) \ | |
238 | asm volatile(LOCK_PREFIX "andl %0,%1" \ | |
239 | : : "r" (~(mask)), "m" (*(addr)) : "memory") | |
240 | ||
241 | #define atomic_set_mask(mask, addr) \ | |
242 | asm volatile(LOCK_PREFIX "orl %0,%1" \ | |
243 | : : "r" ((unsigned)(mask)), "m" (*(addr)) \ | |
244 | : "memory") | |
245 | ||
246 | /* Atomic operations are already serializing on x86 */ | |
247 | #define smp_mb__before_atomic_dec() barrier() | |
248 | #define smp_mb__after_atomic_dec() barrier() | |
249 | #define smp_mb__before_atomic_inc() barrier() | |
250 | #define smp_mb__after_atomic_inc() barrier() | |
251 | ||
96a388de | 252 | #ifdef CONFIG_X86_32 |
a1ce3928 | 253 | # include <asm/atomic64_32.h> |
96a388de | 254 | #else |
a1ce3928 | 255 | # include <asm/atomic64_64.h> |
96a388de | 256 | #endif |
5abbbbf0 | 257 | |
5abbbbf0 | 258 | #endif /* _ASM_X86_ATOMIC_H */ |