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1da177e4 LT |
1 | #ifndef __ARCH_X86_64_ATOMIC__ |
2 | #define __ARCH_X86_64_ATOMIC__ | |
3 | ||
d167a518 | 4 | #include <asm/alternative.h> |
a436ed9c | 5 | #include <asm/cmpxchg.h> |
1da177e4 LT |
6 | |
7 | /* atomic_t should be 32 bit signed type */ | |
8 | ||
9 | /* | |
10 | * Atomic operations that C can't guarantee us. Useful for | |
11 | * resource counting etc.. | |
12 | */ | |
13 | ||
14 | #ifdef CONFIG_SMP | |
15 | #define LOCK "lock ; " | |
16 | #else | |
17 | #define LOCK "" | |
18 | #endif | |
19 | ||
20 | /* | |
21 | * Make sure gcc doesn't try to be clever and move things around | |
22 | * on us. We need to use _exactly_ the address the user gave us, | |
23 | * not some alias that contains the same information. | |
24 | */ | |
f9e9dcb3 | 25 | typedef struct { int counter; } atomic_t; |
1da177e4 LT |
26 | |
27 | #define ATOMIC_INIT(i) { (i) } | |
28 | ||
29 | /** | |
30 | * atomic_read - read atomic variable | |
31 | * @v: pointer of type atomic_t | |
32 | * | |
33 | * Atomically reads the value of @v. | |
34 | */ | |
35 | #define atomic_read(v) ((v)->counter) | |
36 | ||
37 | /** | |
38 | * atomic_set - set atomic variable | |
39 | * @v: pointer of type atomic_t | |
40 | * @i: required value | |
41 | * | |
42 | * Atomically sets the value of @v to @i. | |
43 | */ | |
44 | #define atomic_set(v,i) (((v)->counter) = (i)) | |
45 | ||
46 | /** | |
47 | * atomic_add - add integer to atomic variable | |
48 | * @i: integer value to add | |
49 | * @v: pointer of type atomic_t | |
50 | * | |
51 | * Atomically adds @i to @v. | |
52 | */ | |
53 | static __inline__ void atomic_add(int i, atomic_t *v) | |
54 | { | |
55 | __asm__ __volatile__( | |
d167a518 | 56 | LOCK_PREFIX "addl %1,%0" |
1da177e4 LT |
57 | :"=m" (v->counter) |
58 | :"ir" (i), "m" (v->counter)); | |
59 | } | |
60 | ||
61 | /** | |
62 | * atomic_sub - subtract the atomic variable | |
63 | * @i: integer value to subtract | |
64 | * @v: pointer of type atomic_t | |
65 | * | |
66 | * Atomically subtracts @i from @v. | |
67 | */ | |
68 | static __inline__ void atomic_sub(int i, atomic_t *v) | |
69 | { | |
70 | __asm__ __volatile__( | |
d167a518 | 71 | LOCK_PREFIX "subl %1,%0" |
1da177e4 LT |
72 | :"=m" (v->counter) |
73 | :"ir" (i), "m" (v->counter)); | |
74 | } | |
75 | ||
76 | /** | |
77 | * atomic_sub_and_test - subtract value from variable and test result | |
78 | * @i: integer value to subtract | |
79 | * @v: pointer of type atomic_t | |
80 | * | |
81 | * Atomically subtracts @i from @v and returns | |
82 | * true if the result is zero, or false for all | |
83 | * other cases. | |
84 | */ | |
85 | static __inline__ int atomic_sub_and_test(int i, atomic_t *v) | |
86 | { | |
87 | unsigned char c; | |
88 | ||
89 | __asm__ __volatile__( | |
d167a518 | 90 | LOCK_PREFIX "subl %2,%0; sete %1" |
1da177e4 LT |
91 | :"=m" (v->counter), "=qm" (c) |
92 | :"ir" (i), "m" (v->counter) : "memory"); | |
93 | return c; | |
94 | } | |
95 | ||
96 | /** | |
97 | * atomic_inc - increment atomic variable | |
98 | * @v: pointer of type atomic_t | |
99 | * | |
100 | * Atomically increments @v by 1. | |
101 | */ | |
102 | static __inline__ void atomic_inc(atomic_t *v) | |
103 | { | |
104 | __asm__ __volatile__( | |
d167a518 | 105 | LOCK_PREFIX "incl %0" |
1da177e4 LT |
106 | :"=m" (v->counter) |
107 | :"m" (v->counter)); | |
108 | } | |
109 | ||
110 | /** | |
111 | * atomic_dec - decrement atomic variable | |
112 | * @v: pointer of type atomic_t | |
113 | * | |
114 | * Atomically decrements @v by 1. | |
115 | */ | |
116 | static __inline__ void atomic_dec(atomic_t *v) | |
117 | { | |
118 | __asm__ __volatile__( | |
d167a518 | 119 | LOCK_PREFIX "decl %0" |
1da177e4 LT |
120 | :"=m" (v->counter) |
121 | :"m" (v->counter)); | |
122 | } | |
123 | ||
124 | /** | |
125 | * atomic_dec_and_test - decrement and test | |
126 | * @v: pointer of type atomic_t | |
127 | * | |
128 | * Atomically decrements @v by 1 and | |
129 | * returns true if the result is 0, or false for all other | |
130 | * cases. | |
131 | */ | |
132 | static __inline__ int atomic_dec_and_test(atomic_t *v) | |
133 | { | |
134 | unsigned char c; | |
135 | ||
136 | __asm__ __volatile__( | |
d167a518 | 137 | LOCK_PREFIX "decl %0; sete %1" |
1da177e4 LT |
138 | :"=m" (v->counter), "=qm" (c) |
139 | :"m" (v->counter) : "memory"); | |
140 | return c != 0; | |
141 | } | |
142 | ||
143 | /** | |
144 | * atomic_inc_and_test - increment and test | |
145 | * @v: pointer of type atomic_t | |
146 | * | |
147 | * Atomically increments @v by 1 | |
148 | * and returns true if the result is zero, or false for all | |
149 | * other cases. | |
150 | */ | |
151 | static __inline__ int atomic_inc_and_test(atomic_t *v) | |
152 | { | |
153 | unsigned char c; | |
154 | ||
155 | __asm__ __volatile__( | |
d167a518 | 156 | LOCK_PREFIX "incl %0; sete %1" |
1da177e4 LT |
157 | :"=m" (v->counter), "=qm" (c) |
158 | :"m" (v->counter) : "memory"); | |
159 | return c != 0; | |
160 | } | |
161 | ||
162 | /** | |
163 | * atomic_add_negative - add and test if negative | |
1da177e4 | 164 | * @i: integer value to add |
7c72aaf2 | 165 | * @v: pointer of type atomic_t |
1da177e4 LT |
166 | * |
167 | * Atomically adds @i to @v and returns true | |
168 | * if the result is negative, or false when | |
169 | * result is greater than or equal to zero. | |
170 | */ | |
171 | static __inline__ int atomic_add_negative(int i, atomic_t *v) | |
172 | { | |
173 | unsigned char c; | |
174 | ||
175 | __asm__ __volatile__( | |
d167a518 | 176 | LOCK_PREFIX "addl %2,%0; sets %1" |
1da177e4 LT |
177 | :"=m" (v->counter), "=qm" (c) |
178 | :"ir" (i), "m" (v->counter) : "memory"); | |
179 | return c; | |
180 | } | |
181 | ||
7c72aaf2 HD |
182 | /** |
183 | * atomic_add_return - add and return | |
184 | * @i: integer value to add | |
185 | * @v: pointer of type atomic_t | |
186 | * | |
187 | * Atomically adds @i to @v and returns @i + @v | |
188 | */ | |
189 | static __inline__ int atomic_add_return(int i, atomic_t *v) | |
190 | { | |
191 | int __i = i; | |
192 | __asm__ __volatile__( | |
9dc452ba AK |
193 | LOCK_PREFIX "xaddl %0, %1" |
194 | :"+r" (i), "+m" (v->counter) | |
195 | : : "memory"); | |
7c72aaf2 HD |
196 | return i + __i; |
197 | } | |
198 | ||
199 | static __inline__ int atomic_sub_return(int i, atomic_t *v) | |
200 | { | |
201 | return atomic_add_return(-i,v); | |
202 | } | |
203 | ||
204 | #define atomic_inc_return(v) (atomic_add_return(1,v)) | |
205 | #define atomic_dec_return(v) (atomic_sub_return(1,v)) | |
206 | ||
1da177e4 LT |
207 | /* An 64bit atomic type */ |
208 | ||
209 | typedef struct { volatile long counter; } atomic64_t; | |
210 | ||
211 | #define ATOMIC64_INIT(i) { (i) } | |
212 | ||
213 | /** | |
214 | * atomic64_read - read atomic64 variable | |
215 | * @v: pointer of type atomic64_t | |
216 | * | |
217 | * Atomically reads the value of @v. | |
218 | * Doesn't imply a read memory barrier. | |
219 | */ | |
220 | #define atomic64_read(v) ((v)->counter) | |
221 | ||
222 | /** | |
223 | * atomic64_set - set atomic64 variable | |
224 | * @v: pointer to type atomic64_t | |
225 | * @i: required value | |
226 | * | |
227 | * Atomically sets the value of @v to @i. | |
228 | */ | |
229 | #define atomic64_set(v,i) (((v)->counter) = (i)) | |
230 | ||
231 | /** | |
232 | * atomic64_add - add integer to atomic64 variable | |
233 | * @i: integer value to add | |
234 | * @v: pointer to type atomic64_t | |
235 | * | |
236 | * Atomically adds @i to @v. | |
237 | */ | |
238 | static __inline__ void atomic64_add(long i, atomic64_t *v) | |
239 | { | |
240 | __asm__ __volatile__( | |
d167a518 | 241 | LOCK_PREFIX "addq %1,%0" |
1da177e4 LT |
242 | :"=m" (v->counter) |
243 | :"ir" (i), "m" (v->counter)); | |
244 | } | |
245 | ||
246 | /** | |
247 | * atomic64_sub - subtract the atomic64 variable | |
248 | * @i: integer value to subtract | |
249 | * @v: pointer to type atomic64_t | |
250 | * | |
251 | * Atomically subtracts @i from @v. | |
252 | */ | |
253 | static __inline__ void atomic64_sub(long i, atomic64_t *v) | |
254 | { | |
255 | __asm__ __volatile__( | |
d167a518 | 256 | LOCK_PREFIX "subq %1,%0" |
1da177e4 LT |
257 | :"=m" (v->counter) |
258 | :"ir" (i), "m" (v->counter)); | |
259 | } | |
260 | ||
261 | /** | |
262 | * atomic64_sub_and_test - subtract value from variable and test result | |
263 | * @i: integer value to subtract | |
264 | * @v: pointer to type atomic64_t | |
265 | * | |
266 | * Atomically subtracts @i from @v and returns | |
267 | * true if the result is zero, or false for all | |
268 | * other cases. | |
269 | */ | |
270 | static __inline__ int atomic64_sub_and_test(long i, atomic64_t *v) | |
271 | { | |
272 | unsigned char c; | |
273 | ||
274 | __asm__ __volatile__( | |
d167a518 | 275 | LOCK_PREFIX "subq %2,%0; sete %1" |
1da177e4 LT |
276 | :"=m" (v->counter), "=qm" (c) |
277 | :"ir" (i), "m" (v->counter) : "memory"); | |
278 | return c; | |
279 | } | |
280 | ||
281 | /** | |
282 | * atomic64_inc - increment atomic64 variable | |
283 | * @v: pointer to type atomic64_t | |
284 | * | |
285 | * Atomically increments @v by 1. | |
286 | */ | |
287 | static __inline__ void atomic64_inc(atomic64_t *v) | |
288 | { | |
289 | __asm__ __volatile__( | |
d167a518 | 290 | LOCK_PREFIX "incq %0" |
1da177e4 LT |
291 | :"=m" (v->counter) |
292 | :"m" (v->counter)); | |
293 | } | |
294 | ||
295 | /** | |
296 | * atomic64_dec - decrement atomic64 variable | |
297 | * @v: pointer to type atomic64_t | |
298 | * | |
299 | * Atomically decrements @v by 1. | |
300 | */ | |
301 | static __inline__ void atomic64_dec(atomic64_t *v) | |
302 | { | |
303 | __asm__ __volatile__( | |
d167a518 | 304 | LOCK_PREFIX "decq %0" |
1da177e4 LT |
305 | :"=m" (v->counter) |
306 | :"m" (v->counter)); | |
307 | } | |
308 | ||
309 | /** | |
310 | * atomic64_dec_and_test - decrement and test | |
311 | * @v: pointer to type atomic64_t | |
312 | * | |
313 | * Atomically decrements @v by 1 and | |
314 | * returns true if the result is 0, or false for all other | |
315 | * cases. | |
316 | */ | |
317 | static __inline__ int atomic64_dec_and_test(atomic64_t *v) | |
318 | { | |
319 | unsigned char c; | |
320 | ||
321 | __asm__ __volatile__( | |
d167a518 | 322 | LOCK_PREFIX "decq %0; sete %1" |
1da177e4 LT |
323 | :"=m" (v->counter), "=qm" (c) |
324 | :"m" (v->counter) : "memory"); | |
325 | return c != 0; | |
326 | } | |
327 | ||
328 | /** | |
329 | * atomic64_inc_and_test - increment and test | |
330 | * @v: pointer to type atomic64_t | |
331 | * | |
332 | * Atomically increments @v by 1 | |
333 | * and returns true if the result is zero, or false for all | |
334 | * other cases. | |
335 | */ | |
336 | static __inline__ int atomic64_inc_and_test(atomic64_t *v) | |
337 | { | |
338 | unsigned char c; | |
339 | ||
340 | __asm__ __volatile__( | |
d167a518 | 341 | LOCK_PREFIX "incq %0; sete %1" |
1da177e4 LT |
342 | :"=m" (v->counter), "=qm" (c) |
343 | :"m" (v->counter) : "memory"); | |
344 | return c != 0; | |
345 | } | |
346 | ||
347 | /** | |
348 | * atomic64_add_negative - add and test if negative | |
1da177e4 | 349 | * @i: integer value to add |
7c72aaf2 | 350 | * @v: pointer to type atomic64_t |
1da177e4 LT |
351 | * |
352 | * Atomically adds @i to @v and returns true | |
353 | * if the result is negative, or false when | |
354 | * result is greater than or equal to zero. | |
355 | */ | |
7c72aaf2 | 356 | static __inline__ int atomic64_add_negative(long i, atomic64_t *v) |
1da177e4 LT |
357 | { |
358 | unsigned char c; | |
359 | ||
360 | __asm__ __volatile__( | |
d167a518 | 361 | LOCK_PREFIX "addq %2,%0; sets %1" |
1da177e4 LT |
362 | :"=m" (v->counter), "=qm" (c) |
363 | :"ir" (i), "m" (v->counter) : "memory"); | |
364 | return c; | |
365 | } | |
366 | ||
367 | /** | |
7c72aaf2 | 368 | * atomic64_add_return - add and return |
1da177e4 | 369 | * @i: integer value to add |
7c72aaf2 | 370 | * @v: pointer to type atomic64_t |
1da177e4 LT |
371 | * |
372 | * Atomically adds @i to @v and returns @i + @v | |
373 | */ | |
7c72aaf2 | 374 | static __inline__ long atomic64_add_return(long i, atomic64_t *v) |
1da177e4 | 375 | { |
7c72aaf2 | 376 | long __i = i; |
1da177e4 | 377 | __asm__ __volatile__( |
d167a518 | 378 | LOCK_PREFIX "xaddq %0, %1;" |
79d365a3 MD |
379 | :"+r" (i), "+m" (v->counter) |
380 | : : "memory"); | |
1da177e4 LT |
381 | return i + __i; |
382 | } | |
383 | ||
7c72aaf2 | 384 | static __inline__ long atomic64_sub_return(long i, atomic64_t *v) |
1da177e4 | 385 | { |
7c72aaf2 | 386 | return atomic64_add_return(-i,v); |
1da177e4 LT |
387 | } |
388 | ||
7c72aaf2 HD |
389 | #define atomic64_inc_return(v) (atomic64_add_return(1,v)) |
390 | #define atomic64_dec_return(v) (atomic64_sub_return(1,v)) | |
391 | ||
79d365a3 MD |
392 | #define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new)) |
393 | #define atomic64_xchg(v, new) (xchg(&((v)->counter), new)) | |
394 | ||
395 | #define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new)) | |
ffbf670f | 396 | #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) |
4a6dae6d | 397 | |
8426e1f6 NP |
398 | /** |
399 | * atomic_add_unless - add unless the number is a given value | |
400 | * @v: pointer of type atomic_t | |
401 | * @a: the amount to add to v... | |
402 | * @u: ...unless v is equal to u. | |
403 | * | |
404 | * Atomically adds @a to @v, so long as it was not @u. | |
405 | * Returns non-zero if @v was not @u, and zero otherwise. | |
406 | */ | |
2856f5e3 MD |
407 | static __inline__ int atomic_add_unless(atomic_t *v, int a, int u) |
408 | { | |
409 | int c, old; | |
410 | c = atomic_read(v); | |
411 | for (;;) { | |
412 | if (unlikely(c == (u))) | |
413 | break; | |
414 | old = atomic_cmpxchg((v), c, c + (a)); | |
415 | if (likely(old == c)) | |
416 | break; | |
417 | c = old; | |
418 | } | |
419 | return c != (u); | |
420 | } | |
421 | ||
8426e1f6 NP |
422 | #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) |
423 | ||
79d365a3 MD |
424 | /** |
425 | * atomic64_add_unless - add unless the number is a given value | |
426 | * @v: pointer of type atomic64_t | |
427 | * @a: the amount to add to v... | |
428 | * @u: ...unless v is equal to u. | |
429 | * | |
430 | * Atomically adds @a to @v, so long as it was not @u. | |
431 | * Returns non-zero if @v was not @u, and zero otherwise. | |
432 | */ | |
2856f5e3 MD |
433 | static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u) |
434 | { | |
435 | long c, old; | |
436 | c = atomic64_read(v); | |
437 | for (;;) { | |
438 | if (unlikely(c == (u))) | |
439 | break; | |
440 | old = atomic64_cmpxchg((v), c, c + (a)); | |
441 | if (likely(old == c)) | |
442 | break; | |
443 | c = old; | |
444 | } | |
445 | return c != (u); | |
446 | } | |
447 | ||
79d365a3 MD |
448 | #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) |
449 | ||
1da177e4 LT |
450 | /* These are x86-specific, used by some header files */ |
451 | #define atomic_clear_mask(mask, addr) \ | |
d167a518 | 452 | __asm__ __volatile__(LOCK_PREFIX "andl %0,%1" \ |
1da177e4 LT |
453 | : : "r" (~(mask)),"m" (*addr) : "memory") |
454 | ||
455 | #define atomic_set_mask(mask, addr) \ | |
d167a518 | 456 | __asm__ __volatile__(LOCK_PREFIX "orl %0,%1" \ |
1da177e4 LT |
457 | : : "r" ((unsigned)mask),"m" (*(addr)) : "memory") |
458 | ||
459 | /* Atomic operations are already serializing on x86 */ | |
460 | #define smp_mb__before_atomic_dec() barrier() | |
461 | #define smp_mb__after_atomic_dec() barrier() | |
462 | #define smp_mb__before_atomic_inc() barrier() | |
463 | #define smp_mb__after_atomic_inc() barrier() | |
464 | ||
d3cb4871 | 465 | #include <asm-generic/atomic.h> |
1da177e4 | 466 | #endif |