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1965aae3 PA |
1 | #ifndef _ASM_X86_ATOMIC_32_H |
2 | #define _ASM_X86_ATOMIC_32_H | |
1da177e4 | 3 | |
1da177e4 | 4 | #include <linux/compiler.h> |
ea435467 | 5 | #include <linux/types.h> |
1da177e4 | 6 | #include <asm/processor.h> |
3ce59bb8 | 7 | #include <asm/alternative.h> |
a436ed9c | 8 | #include <asm/cmpxchg.h> |
1da177e4 LT |
9 | |
10 | /* | |
11 | * Atomic operations that C can't guarantee us. Useful for | |
12 | * resource counting etc.. | |
13 | */ | |
14 | ||
1da177e4 LT |
15 | #define ATOMIC_INIT(i) { (i) } |
16 | ||
17 | /** | |
18 | * atomic_read - read atomic variable | |
19 | * @v: pointer of type atomic_t | |
78ff12ee | 20 | * |
1da177e4 | 21 | * Atomically reads the value of @v. |
78ff12ee | 22 | */ |
32171208 IM |
23 | static inline int atomic_read(const atomic_t *v) |
24 | { | |
25 | return v->counter; | |
26 | } | |
1da177e4 LT |
27 | |
28 | /** | |
29 | * atomic_set - set atomic variable | |
30 | * @v: pointer of type atomic_t | |
31 | * @i: required value | |
78ff12ee | 32 | * |
1da177e4 | 33 | * Atomically sets the value of @v to @i. |
78ff12ee | 34 | */ |
8e049ef0 PM |
35 | static inline void atomic_set(atomic_t *v, int i) |
36 | { | |
37 | v->counter = i; | |
38 | } | |
1da177e4 LT |
39 | |
40 | /** | |
41 | * atomic_add - add integer to atomic variable | |
42 | * @i: integer value to add | |
43 | * @v: pointer of type atomic_t | |
78ff12ee | 44 | * |
1da177e4 LT |
45 | * Atomically adds @i to @v. |
46 | */ | |
78ff12ee | 47 | static inline void atomic_add(int i, atomic_t *v) |
1da177e4 | 48 | { |
78ff12ee JP |
49 | asm volatile(LOCK_PREFIX "addl %1,%0" |
50 | : "+m" (v->counter) | |
51 | : "ir" (i)); | |
1da177e4 LT |
52 | } |
53 | ||
54 | /** | |
cc38682f | 55 | * atomic_sub - subtract integer from atomic variable |
1da177e4 LT |
56 | * @i: integer value to subtract |
57 | * @v: pointer of type atomic_t | |
78ff12ee | 58 | * |
1da177e4 LT |
59 | * Atomically subtracts @i from @v. |
60 | */ | |
78ff12ee | 61 | static inline void atomic_sub(int i, atomic_t *v) |
1da177e4 | 62 | { |
78ff12ee JP |
63 | asm volatile(LOCK_PREFIX "subl %1,%0" |
64 | : "+m" (v->counter) | |
65 | : "ir" (i)); | |
1da177e4 LT |
66 | } |
67 | ||
68 | /** | |
69 | * atomic_sub_and_test - subtract value from variable and test result | |
70 | * @i: integer value to subtract | |
71 | * @v: pointer of type atomic_t | |
78ff12ee | 72 | * |
1da177e4 LT |
73 | * Atomically subtracts @i from @v and returns |
74 | * true if the result is zero, or false for all | |
75 | * other cases. | |
76 | */ | |
78ff12ee | 77 | static inline int atomic_sub_and_test(int i, atomic_t *v) |
1da177e4 LT |
78 | { |
79 | unsigned char c; | |
80 | ||
78ff12ee JP |
81 | asm volatile(LOCK_PREFIX "subl %2,%0; sete %1" |
82 | : "+m" (v->counter), "=qm" (c) | |
83 | : "ir" (i) : "memory"); | |
1da177e4 LT |
84 | return c; |
85 | } | |
86 | ||
87 | /** | |
88 | * atomic_inc - increment atomic variable | |
89 | * @v: pointer of type atomic_t | |
78ff12ee | 90 | * |
1da177e4 | 91 | * Atomically increments @v by 1. |
78ff12ee JP |
92 | */ |
93 | static inline void atomic_inc(atomic_t *v) | |
1da177e4 | 94 | { |
78ff12ee JP |
95 | asm volatile(LOCK_PREFIX "incl %0" |
96 | : "+m" (v->counter)); | |
1da177e4 LT |
97 | } |
98 | ||
99 | /** | |
100 | * atomic_dec - decrement atomic variable | |
101 | * @v: pointer of type atomic_t | |
78ff12ee | 102 | * |
1da177e4 | 103 | * Atomically decrements @v by 1. |
78ff12ee JP |
104 | */ |
105 | static inline void atomic_dec(atomic_t *v) | |
1da177e4 | 106 | { |
78ff12ee JP |
107 | asm volatile(LOCK_PREFIX "decl %0" |
108 | : "+m" (v->counter)); | |
1da177e4 LT |
109 | } |
110 | ||
111 | /** | |
112 | * atomic_dec_and_test - decrement and test | |
113 | * @v: pointer of type atomic_t | |
78ff12ee | 114 | * |
1da177e4 LT |
115 | * Atomically decrements @v by 1 and |
116 | * returns true if the result is 0, or false for all other | |
117 | * cases. | |
78ff12ee JP |
118 | */ |
119 | static inline int atomic_dec_and_test(atomic_t *v) | |
1da177e4 LT |
120 | { |
121 | unsigned char c; | |
122 | ||
78ff12ee JP |
123 | asm volatile(LOCK_PREFIX "decl %0; sete %1" |
124 | : "+m" (v->counter), "=qm" (c) | |
125 | : : "memory"); | |
1da177e4 LT |
126 | return c != 0; |
127 | } | |
128 | ||
129 | /** | |
78ff12ee | 130 | * atomic_inc_and_test - increment and test |
1da177e4 | 131 | * @v: pointer of type atomic_t |
78ff12ee | 132 | * |
1da177e4 LT |
133 | * Atomically increments @v by 1 |
134 | * and returns true if the result is zero, or false for all | |
135 | * other cases. | |
78ff12ee JP |
136 | */ |
137 | static inline int atomic_inc_and_test(atomic_t *v) | |
1da177e4 LT |
138 | { |
139 | unsigned char c; | |
140 | ||
78ff12ee JP |
141 | asm volatile(LOCK_PREFIX "incl %0; sete %1" |
142 | : "+m" (v->counter), "=qm" (c) | |
143 | : : "memory"); | |
1da177e4 LT |
144 | return c != 0; |
145 | } | |
146 | ||
147 | /** | |
148 | * atomic_add_negative - add and test if negative | |
1da177e4 | 149 | * @i: integer value to add |
3ce59bb8 | 150 | * @v: pointer of type atomic_t |
78ff12ee | 151 | * |
1da177e4 LT |
152 | * Atomically adds @i to @v and returns true |
153 | * if the result is negative, or false when | |
154 | * result is greater than or equal to zero. | |
78ff12ee JP |
155 | */ |
156 | static inline int atomic_add_negative(int i, atomic_t *v) | |
1da177e4 LT |
157 | { |
158 | unsigned char c; | |
159 | ||
78ff12ee JP |
160 | asm volatile(LOCK_PREFIX "addl %2,%0; sets %1" |
161 | : "+m" (v->counter), "=qm" (c) | |
162 | : "ir" (i) : "memory"); | |
1da177e4 LT |
163 | return c; |
164 | } | |
165 | ||
166 | /** | |
cc38682f | 167 | * atomic_add_return - add integer and return |
1da177e4 | 168 | * @i: integer value to add |
3ce59bb8 | 169 | * @v: pointer of type atomic_t |
1da177e4 LT |
170 | * |
171 | * Atomically adds @i to @v and returns @i + @v | |
172 | */ | |
78ff12ee | 173 | static inline int atomic_add_return(int i, atomic_t *v) |
1da177e4 LT |
174 | { |
175 | int __i; | |
176 | #ifdef CONFIG_M386 | |
1bb858f2 | 177 | unsigned long flags; |
78ff12ee | 178 | if (unlikely(boot_cpu_data.x86 <= 3)) |
1da177e4 LT |
179 | goto no_xadd; |
180 | #endif | |
181 | /* Modern 486+ processor */ | |
182 | __i = i; | |
78ff12ee JP |
183 | asm volatile(LOCK_PREFIX "xaddl %0, %1" |
184 | : "+r" (i), "+m" (v->counter) | |
185 | : : "memory"); | |
1da177e4 LT |
186 | return i + __i; |
187 | ||
188 | #ifdef CONFIG_M386 | |
189 | no_xadd: /* Legacy 386 processor */ | |
1bb858f2 | 190 | local_irq_save(flags); |
1da177e4 LT |
191 | __i = atomic_read(v); |
192 | atomic_set(v, i + __i); | |
1bb858f2 | 193 | local_irq_restore(flags); |
1da177e4 LT |
194 | return i + __i; |
195 | #endif | |
196 | } | |
197 | ||
cc38682f RD |
198 | /** |
199 | * atomic_sub_return - subtract integer and return | |
200 | * @v: pointer of type atomic_t | |
201 | * @i: integer value to subtract | |
202 | * | |
203 | * Atomically subtracts @i from @v and returns @v - @i | |
204 | */ | |
78ff12ee | 205 | static inline int atomic_sub_return(int i, atomic_t *v) |
1da177e4 | 206 | { |
78ff12ee | 207 | return atomic_add_return(-i, v); |
1da177e4 LT |
208 | } |
209 | ||
3ce59bb8 BG |
210 | #define atomic_inc_return(v) (atomic_add_return(1, v)) |
211 | #define atomic_dec_return(v) (atomic_sub_return(1, v)) | |
212 | ||
8e049ef0 PM |
213 | static inline int atomic_cmpxchg(atomic_t *v, int old, int new) |
214 | { | |
215 | return cmpxchg(&v->counter, old, new); | |
216 | } | |
217 | ||
218 | static inline int atomic_xchg(atomic_t *v, int new) | |
219 | { | |
220 | return xchg(&v->counter, new); | |
221 | } | |
4a6dae6d | 222 | |
8426e1f6 | 223 | /** |
72fd4a35 | 224 | * atomic_add_unless - add unless the number is already a given value |
8426e1f6 NP |
225 | * @v: pointer of type atomic_t |
226 | * @a: the amount to add to v... | |
227 | * @u: ...unless v is equal to u. | |
228 | * | |
72fd4a35 | 229 | * Atomically adds @a to @v, so long as @v was not already @u. |
8426e1f6 NP |
230 | * Returns non-zero if @v was not @u, and zero otherwise. |
231 | */ | |
78ff12ee | 232 | static inline int atomic_add_unless(atomic_t *v, int a, int u) |
2856f5e3 MD |
233 | { |
234 | int c, old; | |
235 | c = atomic_read(v); | |
236 | for (;;) { | |
237 | if (unlikely(c == (u))) | |
238 | break; | |
239 | old = atomic_cmpxchg((v), c, c + (a)); | |
240 | if (likely(old == c)) | |
241 | break; | |
242 | c = old; | |
243 | } | |
244 | return c != (u); | |
245 | } | |
246 | ||
8426e1f6 NP |
247 | #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) |
248 | ||
3ce59bb8 BG |
249 | /** |
250 | * atomic_inc_short - increment of a short integer | |
251 | * @v: pointer to type int | |
252 | * | |
253 | * Atomically adds 1 to @v | |
254 | * Returns the new value of @u | |
255 | */ | |
256 | static inline short int atomic_inc_short(short int *v) | |
257 | { | |
258 | asm(LOCK_PREFIX "addw $1, %0" : "+m" (*v)); | |
259 | return *v; | |
260 | } | |
261 | ||
262 | #ifdef CONFIG_X86_64 | |
263 | /** | |
264 | * atomic_or_long - OR of two long integers | |
265 | * @v1: pointer to type unsigned long | |
266 | * @v2: pointer to type unsigned long | |
267 | * | |
268 | * Atomically ORs @v1 and @v2 | |
269 | * Returns the result of the OR | |
270 | */ | |
271 | static inline void atomic_or_long(unsigned long *v1, unsigned long v2) | |
272 | { | |
273 | asm(LOCK_PREFIX "orq %1, %0" : "+m" (*v1) : "r" (v2)); | |
274 | } | |
275 | #endif | |
1da177e4 LT |
276 | |
277 | /* These are x86-specific, used by some header files */ | |
78ff12ee JP |
278 | #define atomic_clear_mask(mask, addr) \ |
279 | asm volatile(LOCK_PREFIX "andl %0,%1" \ | |
280 | : : "r" (~(mask)), "m" (*(addr)) : "memory") | |
1da177e4 | 281 | |
78ff12ee | 282 | #define atomic_set_mask(mask, addr) \ |
3ce59bb8 BG |
283 | asm volatile(LOCK_PREFIX "orl %0,%1" \ |
284 | : : "r" ((unsigned)(mask)), "m" (*(addr)) \ | |
285 | : "memory") | |
1da177e4 LT |
286 | |
287 | /* Atomic operations are already serializing on x86 */ | |
288 | #define smp_mb__before_atomic_dec() barrier() | |
289 | #define smp_mb__after_atomic_dec() barrier() | |
290 | #define smp_mb__before_atomic_inc() barrier() | |
291 | #define smp_mb__after_atomic_inc() barrier() | |
292 | ||
1a3b1d89 | 293 | #include <asm/atomic64_32.h> |
72099ed2 | 294 | #include <asm-generic/atomic-long.h> |
1965aae3 | 295 | #endif /* _ASM_X86_ATOMIC_32_H */ |