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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> |
d00a5692 | 10 | #include <asm/barrier.h> |
5abbbbf0 BG |
11 | |
12 | /* | |
13 | * Atomic operations that C can't guarantee us. Useful for | |
14 | * resource counting etc.. | |
15 | */ | |
16 | ||
17 | #define ATOMIC_INIT(i) { (i) } | |
18 | ||
19 | /** | |
20 | * atomic_read - read atomic variable | |
21 | * @v: pointer of type atomic_t | |
22 | * | |
23 | * Atomically reads the value of @v. | |
24 | */ | |
25 | static inline int atomic_read(const atomic_t *v) | |
26 | { | |
f3d46f9d | 27 | return (*(volatile int *)&(v)->counter); |
5abbbbf0 BG |
28 | } |
29 | ||
30 | /** | |
31 | * atomic_set - set atomic variable | |
32 | * @v: pointer of type atomic_t | |
33 | * @i: required value | |
34 | * | |
35 | * Atomically sets the value of @v to @i. | |
36 | */ | |
37 | static inline void atomic_set(atomic_t *v, int i) | |
38 | { | |
39 | v->counter = i; | |
40 | } | |
41 | ||
42 | /** | |
43 | * atomic_add - add integer to atomic variable | |
44 | * @i: integer value to add | |
45 | * @v: pointer of type atomic_t | |
46 | * | |
47 | * Atomically adds @i to @v. | |
48 | */ | |
49 | static inline void atomic_add(int i, atomic_t *v) | |
50 | { | |
51 | asm volatile(LOCK_PREFIX "addl %1,%0" | |
52 | : "+m" (v->counter) | |
53 | : "ir" (i)); | |
54 | } | |
55 | ||
56 | /** | |
57 | * atomic_sub - subtract integer from atomic variable | |
58 | * @i: integer value to subtract | |
59 | * @v: pointer of type atomic_t | |
60 | * | |
61 | * Atomically subtracts @i from @v. | |
62 | */ | |
63 | static inline void atomic_sub(int i, atomic_t *v) | |
64 | { | |
65 | asm volatile(LOCK_PREFIX "subl %1,%0" | |
66 | : "+m" (v->counter) | |
67 | : "ir" (i)); | |
68 | } | |
69 | ||
70 | /** | |
71 | * atomic_sub_and_test - subtract value from variable and test result | |
72 | * @i: integer value to subtract | |
73 | * @v: pointer of type atomic_t | |
74 | * | |
75 | * Atomically subtracts @i from @v and returns | |
76 | * true if the result is zero, or false for all | |
77 | * other cases. | |
78 | */ | |
79 | static inline int atomic_sub_and_test(int i, atomic_t *v) | |
80 | { | |
e0f6dec3 | 81 | GEN_BINARY_RMWcc(LOCK_PREFIX "subl", v->counter, "er", i, "%0", "e"); |
5abbbbf0 BG |
82 | } |
83 | ||
84 | /** | |
85 | * atomic_inc - increment atomic variable | |
86 | * @v: pointer of type atomic_t | |
87 | * | |
88 | * Atomically increments @v by 1. | |
89 | */ | |
90 | static inline void atomic_inc(atomic_t *v) | |
91 | { | |
92 | asm volatile(LOCK_PREFIX "incl %0" | |
93 | : "+m" (v->counter)); | |
94 | } | |
95 | ||
96 | /** | |
97 | * atomic_dec - decrement atomic variable | |
98 | * @v: pointer of type atomic_t | |
99 | * | |
100 | * Atomically decrements @v by 1. | |
101 | */ | |
102 | static inline void atomic_dec(atomic_t *v) | |
103 | { | |
104 | asm volatile(LOCK_PREFIX "decl %0" | |
105 | : "+m" (v->counter)); | |
106 | } | |
107 | ||
108 | /** | |
109 | * atomic_dec_and_test - decrement and test | |
110 | * @v: pointer of type atomic_t | |
111 | * | |
112 | * Atomically decrements @v by 1 and | |
113 | * returns true if the result is 0, or false for all other | |
114 | * cases. | |
115 | */ | |
116 | static inline int atomic_dec_and_test(atomic_t *v) | |
117 | { | |
0c44c2d0 | 118 | GEN_UNARY_RMWcc(LOCK_PREFIX "decl", v->counter, "%0", "e"); |
5abbbbf0 BG |
119 | } |
120 | ||
121 | /** | |
122 | * atomic_inc_and_test - increment and test | |
123 | * @v: pointer of type atomic_t | |
124 | * | |
125 | * Atomically increments @v by 1 | |
126 | * and returns true if the result is zero, or false for all | |
127 | * other cases. | |
128 | */ | |
129 | static inline int atomic_inc_and_test(atomic_t *v) | |
130 | { | |
0c44c2d0 | 131 | GEN_UNARY_RMWcc(LOCK_PREFIX "incl", v->counter, "%0", "e"); |
5abbbbf0 BG |
132 | } |
133 | ||
134 | /** | |
135 | * atomic_add_negative - add and test if negative | |
136 | * @i: integer value to add | |
137 | * @v: pointer of type atomic_t | |
138 | * | |
139 | * Atomically adds @i to @v and returns true | |
140 | * if the result is negative, or false when | |
141 | * result is greater than or equal to zero. | |
142 | */ | |
143 | static inline int atomic_add_negative(int i, atomic_t *v) | |
144 | { | |
e0f6dec3 | 145 | GEN_BINARY_RMWcc(LOCK_PREFIX "addl", v->counter, "er", i, "%0", "s"); |
5abbbbf0 BG |
146 | } |
147 | ||
148 | /** | |
149 | * atomic_add_return - add integer and return | |
150 | * @i: integer value to add | |
151 | * @v: pointer of type atomic_t | |
152 | * | |
153 | * Atomically adds @i to @v and returns @i + @v | |
154 | */ | |
155 | static inline int atomic_add_return(int i, atomic_t *v) | |
156 | { | |
8b8bc2f7 | 157 | return i + xadd(&v->counter, i); |
5abbbbf0 BG |
158 | } |
159 | ||
160 | /** | |
161 | * atomic_sub_return - subtract integer and return | |
162 | * @v: pointer of type atomic_t | |
163 | * @i: integer value to subtract | |
164 | * | |
165 | * Atomically subtracts @i from @v and returns @v - @i | |
166 | */ | |
167 | static inline int atomic_sub_return(int i, atomic_t *v) | |
168 | { | |
169 | return atomic_add_return(-i, v); | |
170 | } | |
171 | ||
172 | #define atomic_inc_return(v) (atomic_add_return(1, v)) | |
173 | #define atomic_dec_return(v) (atomic_sub_return(1, v)) | |
174 | ||
175 | static inline int atomic_cmpxchg(atomic_t *v, int old, int new) | |
176 | { | |
177 | return cmpxchg(&v->counter, old, new); | |
178 | } | |
179 | ||
180 | static inline int atomic_xchg(atomic_t *v, int new) | |
181 | { | |
182 | return xchg(&v->counter, new); | |
183 | } | |
184 | ||
185 | /** | |
f24219b4 | 186 | * __atomic_add_unless - add unless the number is already a given value |
5abbbbf0 BG |
187 | * @v: pointer of type atomic_t |
188 | * @a: the amount to add to v... | |
189 | * @u: ...unless v is equal to u. | |
190 | * | |
191 | * Atomically adds @a to @v, so long as @v was not already @u. | |
f24219b4 | 192 | * Returns the old value of @v. |
5abbbbf0 | 193 | */ |
f24219b4 | 194 | static inline int __atomic_add_unless(atomic_t *v, int a, int u) |
5abbbbf0 BG |
195 | { |
196 | int c, old; | |
197 | c = atomic_read(v); | |
198 | for (;;) { | |
199 | if (unlikely(c == (u))) | |
200 | break; | |
201 | old = atomic_cmpxchg((v), c, c + (a)); | |
202 | if (likely(old == c)) | |
203 | break; | |
204 | c = old; | |
205 | } | |
f24219b4 | 206 | return c; |
5abbbbf0 BG |
207 | } |
208 | ||
5abbbbf0 BG |
209 | /** |
210 | * atomic_inc_short - increment of a short integer | |
211 | * @v: pointer to type int | |
212 | * | |
213 | * Atomically adds 1 to @v | |
214 | * Returns the new value of @u | |
215 | */ | |
216 | static inline short int atomic_inc_short(short int *v) | |
217 | { | |
218 | asm(LOCK_PREFIX "addw $1, %0" : "+m" (*v)); | |
219 | return *v; | |
220 | } | |
221 | ||
222 | #ifdef CONFIG_X86_64 | |
223 | /** | |
224 | * atomic_or_long - OR of two long integers | |
225 | * @v1: pointer to type unsigned long | |
226 | * @v2: pointer to type unsigned long | |
227 | * | |
228 | * Atomically ORs @v1 and @v2 | |
229 | * Returns the result of the OR | |
230 | */ | |
231 | static inline void atomic_or_long(unsigned long *v1, unsigned long v2) | |
232 | { | |
233 | asm(LOCK_PREFIX "orq %1, %0" : "+m" (*v1) : "r" (v2)); | |
234 | } | |
235 | #endif | |
236 | ||
237 | /* These are x86-specific, used by some header files */ | |
238 | #define atomic_clear_mask(mask, addr) \ | |
239 | asm volatile(LOCK_PREFIX "andl %0,%1" \ | |
240 | : : "r" (~(mask)), "m" (*(addr)) : "memory") | |
241 | ||
242 | #define atomic_set_mask(mask, addr) \ | |
243 | asm volatile(LOCK_PREFIX "orl %0,%1" \ | |
244 | : : "r" ((unsigned)(mask)), "m" (*(addr)) \ | |
245 | : "memory") | |
246 | ||
96a388de | 247 | #ifdef CONFIG_X86_32 |
a1ce3928 | 248 | # include <asm/atomic64_32.h> |
96a388de | 249 | #else |
a1ce3928 | 250 | # include <asm/atomic64_64.h> |
96a388de | 251 | #endif |
5abbbbf0 | 252 | |
5abbbbf0 | 253 | #endif /* _ASM_X86_ATOMIC_H */ |