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