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1da177e4 | 1 | /* |
4baa9922 | 2 | * arch/arm/include/asm/atomic.h |
1da177e4 LT |
3 | * |
4 | * Copyright (C) 1996 Russell King. | |
5 | * Copyright (C) 2002 Deep Blue Solutions Ltd. | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | #ifndef __ASM_ARM_ATOMIC_H | |
12 | #define __ASM_ARM_ATOMIC_H | |
13 | ||
8dc39b88 | 14 | #include <linux/compiler.h> |
ea435467 | 15 | #include <linux/types.h> |
2856f5e3 | 16 | #include <asm/system.h> |
1da177e4 | 17 | |
1da177e4 LT |
18 | #define ATOMIC_INIT(i) { (i) } |
19 | ||
20 | #ifdef __KERNEL__ | |
21 | ||
200b812d CM |
22 | /* |
23 | * On ARM, ordinary assignment (str instruction) doesn't clear the local | |
24 | * strex/ldrex monitor on some implementations. The reason we can use it for | |
25 | * atomic_set() is the clrex or dummy strex done on every exception return. | |
26 | */ | |
f3d46f9d | 27 | #define atomic_read(v) (*(volatile int *)&(v)->counter) |
200b812d | 28 | #define atomic_set(v,i) (((v)->counter) = (i)) |
1da177e4 LT |
29 | |
30 | #if __LINUX_ARM_ARCH__ >= 6 | |
31 | ||
32 | /* | |
33 | * ARMv6 UP and SMP safe atomic ops. We use load exclusive and | |
34 | * store exclusive to ensure that these are atomic. We may loop | |
200b812d | 35 | * to ensure that the update happens. |
1da177e4 | 36 | */ |
bac4e960 RK |
37 | static inline void atomic_add(int i, atomic_t *v) |
38 | { | |
39 | unsigned long tmp; | |
40 | int result; | |
41 | ||
42 | __asm__ __volatile__("@ atomic_add\n" | |
398aa668 WD |
43 | "1: ldrex %0, [%3]\n" |
44 | " add %0, %0, %4\n" | |
45 | " strex %1, %0, [%3]\n" | |
bac4e960 RK |
46 | " teq %1, #0\n" |
47 | " bne 1b" | |
398aa668 | 48 | : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) |
bac4e960 RK |
49 | : "r" (&v->counter), "Ir" (i) |
50 | : "cc"); | |
51 | } | |
52 | ||
1da177e4 LT |
53 | static inline int atomic_add_return(int i, atomic_t *v) |
54 | { | |
55 | unsigned long tmp; | |
56 | int result; | |
57 | ||
bac4e960 RK |
58 | smp_mb(); |
59 | ||
1da177e4 | 60 | __asm__ __volatile__("@ atomic_add_return\n" |
398aa668 WD |
61 | "1: ldrex %0, [%3]\n" |
62 | " add %0, %0, %4\n" | |
63 | " strex %1, %0, [%3]\n" | |
1da177e4 LT |
64 | " teq %1, #0\n" |
65 | " bne 1b" | |
398aa668 | 66 | : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) |
1da177e4 LT |
67 | : "r" (&v->counter), "Ir" (i) |
68 | : "cc"); | |
69 | ||
bac4e960 RK |
70 | smp_mb(); |
71 | ||
1da177e4 LT |
72 | return result; |
73 | } | |
74 | ||
bac4e960 RK |
75 | static inline void atomic_sub(int i, atomic_t *v) |
76 | { | |
77 | unsigned long tmp; | |
78 | int result; | |
79 | ||
80 | __asm__ __volatile__("@ atomic_sub\n" | |
398aa668 WD |
81 | "1: ldrex %0, [%3]\n" |
82 | " sub %0, %0, %4\n" | |
83 | " strex %1, %0, [%3]\n" | |
bac4e960 RK |
84 | " teq %1, #0\n" |
85 | " bne 1b" | |
398aa668 | 86 | : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) |
bac4e960 RK |
87 | : "r" (&v->counter), "Ir" (i) |
88 | : "cc"); | |
89 | } | |
90 | ||
1da177e4 LT |
91 | static inline int atomic_sub_return(int i, atomic_t *v) |
92 | { | |
93 | unsigned long tmp; | |
94 | int result; | |
95 | ||
bac4e960 RK |
96 | smp_mb(); |
97 | ||
1da177e4 | 98 | __asm__ __volatile__("@ atomic_sub_return\n" |
398aa668 WD |
99 | "1: ldrex %0, [%3]\n" |
100 | " sub %0, %0, %4\n" | |
101 | " strex %1, %0, [%3]\n" | |
1da177e4 LT |
102 | " teq %1, #0\n" |
103 | " bne 1b" | |
398aa668 | 104 | : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) |
1da177e4 LT |
105 | : "r" (&v->counter), "Ir" (i) |
106 | : "cc"); | |
107 | ||
bac4e960 RK |
108 | smp_mb(); |
109 | ||
1da177e4 LT |
110 | return result; |
111 | } | |
112 | ||
4a6dae6d NP |
113 | static inline int atomic_cmpxchg(atomic_t *ptr, int old, int new) |
114 | { | |
49ee57a3 | 115 | unsigned long oldval, res; |
4a6dae6d | 116 | |
bac4e960 RK |
117 | smp_mb(); |
118 | ||
4a6dae6d NP |
119 | do { |
120 | __asm__ __volatile__("@ atomic_cmpxchg\n" | |
398aa668 | 121 | "ldrex %1, [%3]\n" |
a7d06833 | 122 | "mov %0, #0\n" |
398aa668 WD |
123 | "teq %1, %4\n" |
124 | "strexeq %0, %5, [%3]\n" | |
125 | : "=&r" (res), "=&r" (oldval), "+Qo" (ptr->counter) | |
4a6dae6d NP |
126 | : "r" (&ptr->counter), "Ir" (old), "r" (new) |
127 | : "cc"); | |
128 | } while (res); | |
129 | ||
bac4e960 RK |
130 | smp_mb(); |
131 | ||
4a6dae6d NP |
132 | return oldval; |
133 | } | |
134 | ||
1da177e4 LT |
135 | static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) |
136 | { | |
137 | unsigned long tmp, tmp2; | |
138 | ||
139 | __asm__ __volatile__("@ atomic_clear_mask\n" | |
398aa668 WD |
140 | "1: ldrex %0, [%3]\n" |
141 | " bic %0, %0, %4\n" | |
142 | " strex %1, %0, [%3]\n" | |
1da177e4 LT |
143 | " teq %1, #0\n" |
144 | " bne 1b" | |
398aa668 | 145 | : "=&r" (tmp), "=&r" (tmp2), "+Qo" (*addr) |
1da177e4 LT |
146 | : "r" (addr), "Ir" (mask) |
147 | : "cc"); | |
148 | } | |
149 | ||
150 | #else /* ARM_ARCH_6 */ | |
151 | ||
1da177e4 LT |
152 | #ifdef CONFIG_SMP |
153 | #error SMP not supported on pre-ARMv6 CPUs | |
154 | #endif | |
155 | ||
1da177e4 LT |
156 | static inline int atomic_add_return(int i, atomic_t *v) |
157 | { | |
158 | unsigned long flags; | |
159 | int val; | |
160 | ||
8dd5c845 | 161 | raw_local_irq_save(flags); |
1da177e4 LT |
162 | val = v->counter; |
163 | v->counter = val += i; | |
8dd5c845 | 164 | raw_local_irq_restore(flags); |
1da177e4 LT |
165 | |
166 | return val; | |
167 | } | |
bac4e960 | 168 | #define atomic_add(i, v) (void) atomic_add_return(i, v) |
1da177e4 LT |
169 | |
170 | static inline int atomic_sub_return(int i, atomic_t *v) | |
171 | { | |
172 | unsigned long flags; | |
173 | int val; | |
174 | ||
8dd5c845 | 175 | raw_local_irq_save(flags); |
1da177e4 LT |
176 | val = v->counter; |
177 | v->counter = val -= i; | |
8dd5c845 | 178 | raw_local_irq_restore(flags); |
1da177e4 LT |
179 | |
180 | return val; | |
181 | } | |
bac4e960 | 182 | #define atomic_sub(i, v) (void) atomic_sub_return(i, v) |
1da177e4 | 183 | |
4a6dae6d NP |
184 | static inline int atomic_cmpxchg(atomic_t *v, int old, int new) |
185 | { | |
186 | int ret; | |
187 | unsigned long flags; | |
188 | ||
8dd5c845 | 189 | raw_local_irq_save(flags); |
4a6dae6d NP |
190 | ret = v->counter; |
191 | if (likely(ret == old)) | |
192 | v->counter = new; | |
8dd5c845 | 193 | raw_local_irq_restore(flags); |
4a6dae6d NP |
194 | |
195 | return ret; | |
196 | } | |
197 | ||
1da177e4 LT |
198 | static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) |
199 | { | |
200 | unsigned long flags; | |
201 | ||
8dd5c845 | 202 | raw_local_irq_save(flags); |
1da177e4 | 203 | *addr &= ~mask; |
8dd5c845 | 204 | raw_local_irq_restore(flags); |
1da177e4 LT |
205 | } |
206 | ||
207 | #endif /* __LINUX_ARM_ARCH__ */ | |
208 | ||
ffbf670f IM |
209 | #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) |
210 | ||
8426e1f6 NP |
211 | static inline int atomic_add_unless(atomic_t *v, int a, int u) |
212 | { | |
213 | int c, old; | |
214 | ||
215 | c = atomic_read(v); | |
216 | while (c != u && (old = atomic_cmpxchg((v), c, c + a)) != c) | |
217 | c = old; | |
218 | return c != u; | |
219 | } | |
8426e1f6 | 220 | |
bac4e960 RK |
221 | #define atomic_inc(v) atomic_add(1, v) |
222 | #define atomic_dec(v) atomic_sub(1, v) | |
1da177e4 LT |
223 | |
224 | #define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0) | |
225 | #define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0) | |
226 | #define atomic_inc_return(v) (atomic_add_return(1, v)) | |
227 | #define atomic_dec_return(v) (atomic_sub_return(1, v)) | |
228 | #define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0) | |
229 | ||
230 | #define atomic_add_negative(i,v) (atomic_add_return(i, v) < 0) | |
231 | ||
bac4e960 RK |
232 | #define smp_mb__before_atomic_dec() smp_mb() |
233 | #define smp_mb__after_atomic_dec() smp_mb() | |
234 | #define smp_mb__before_atomic_inc() smp_mb() | |
235 | #define smp_mb__after_atomic_inc() smp_mb() | |
1da177e4 | 236 | |
24b44a66 WD |
237 | #ifndef CONFIG_GENERIC_ATOMIC64 |
238 | typedef struct { | |
239 | u64 __aligned(8) counter; | |
240 | } atomic64_t; | |
241 | ||
242 | #define ATOMIC64_INIT(i) { (i) } | |
243 | ||
244 | static inline u64 atomic64_read(atomic64_t *v) | |
245 | { | |
246 | u64 result; | |
247 | ||
248 | __asm__ __volatile__("@ atomic64_read\n" | |
249 | " ldrexd %0, %H0, [%1]" | |
250 | : "=&r" (result) | |
398aa668 | 251 | : "r" (&v->counter), "Qo" (v->counter) |
24b44a66 WD |
252 | ); |
253 | ||
254 | return result; | |
255 | } | |
256 | ||
257 | static inline void atomic64_set(atomic64_t *v, u64 i) | |
258 | { | |
259 | u64 tmp; | |
260 | ||
261 | __asm__ __volatile__("@ atomic64_set\n" | |
398aa668 WD |
262 | "1: ldrexd %0, %H0, [%2]\n" |
263 | " strexd %0, %3, %H3, [%2]\n" | |
24b44a66 WD |
264 | " teq %0, #0\n" |
265 | " bne 1b" | |
398aa668 | 266 | : "=&r" (tmp), "=Qo" (v->counter) |
24b44a66 WD |
267 | : "r" (&v->counter), "r" (i) |
268 | : "cc"); | |
269 | } | |
270 | ||
271 | static inline void atomic64_add(u64 i, atomic64_t *v) | |
272 | { | |
273 | u64 result; | |
274 | unsigned long tmp; | |
275 | ||
276 | __asm__ __volatile__("@ atomic64_add\n" | |
398aa668 WD |
277 | "1: ldrexd %0, %H0, [%3]\n" |
278 | " adds %0, %0, %4\n" | |
279 | " adc %H0, %H0, %H4\n" | |
280 | " strexd %1, %0, %H0, [%3]\n" | |
24b44a66 WD |
281 | " teq %1, #0\n" |
282 | " bne 1b" | |
398aa668 | 283 | : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) |
24b44a66 WD |
284 | : "r" (&v->counter), "r" (i) |
285 | : "cc"); | |
286 | } | |
287 | ||
288 | static inline u64 atomic64_add_return(u64 i, atomic64_t *v) | |
289 | { | |
290 | u64 result; | |
291 | unsigned long tmp; | |
292 | ||
293 | smp_mb(); | |
294 | ||
295 | __asm__ __volatile__("@ atomic64_add_return\n" | |
398aa668 WD |
296 | "1: ldrexd %0, %H0, [%3]\n" |
297 | " adds %0, %0, %4\n" | |
298 | " adc %H0, %H0, %H4\n" | |
299 | " strexd %1, %0, %H0, [%3]\n" | |
24b44a66 WD |
300 | " teq %1, #0\n" |
301 | " bne 1b" | |
398aa668 | 302 | : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) |
24b44a66 WD |
303 | : "r" (&v->counter), "r" (i) |
304 | : "cc"); | |
305 | ||
306 | smp_mb(); | |
307 | ||
308 | return result; | |
309 | } | |
310 | ||
311 | static inline void atomic64_sub(u64 i, atomic64_t *v) | |
312 | { | |
313 | u64 result; | |
314 | unsigned long tmp; | |
315 | ||
316 | __asm__ __volatile__("@ atomic64_sub\n" | |
398aa668 WD |
317 | "1: ldrexd %0, %H0, [%3]\n" |
318 | " subs %0, %0, %4\n" | |
319 | " sbc %H0, %H0, %H4\n" | |
320 | " strexd %1, %0, %H0, [%3]\n" | |
24b44a66 WD |
321 | " teq %1, #0\n" |
322 | " bne 1b" | |
398aa668 | 323 | : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) |
24b44a66 WD |
324 | : "r" (&v->counter), "r" (i) |
325 | : "cc"); | |
326 | } | |
327 | ||
328 | static inline u64 atomic64_sub_return(u64 i, atomic64_t *v) | |
329 | { | |
330 | u64 result; | |
331 | unsigned long tmp; | |
332 | ||
333 | smp_mb(); | |
334 | ||
335 | __asm__ __volatile__("@ atomic64_sub_return\n" | |
398aa668 WD |
336 | "1: ldrexd %0, %H0, [%3]\n" |
337 | " subs %0, %0, %4\n" | |
338 | " sbc %H0, %H0, %H4\n" | |
339 | " strexd %1, %0, %H0, [%3]\n" | |
24b44a66 WD |
340 | " teq %1, #0\n" |
341 | " bne 1b" | |
398aa668 | 342 | : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) |
24b44a66 WD |
343 | : "r" (&v->counter), "r" (i) |
344 | : "cc"); | |
345 | ||
346 | smp_mb(); | |
347 | ||
348 | return result; | |
349 | } | |
350 | ||
351 | static inline u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old, u64 new) | |
352 | { | |
353 | u64 oldval; | |
354 | unsigned long res; | |
355 | ||
356 | smp_mb(); | |
357 | ||
358 | do { | |
359 | __asm__ __volatile__("@ atomic64_cmpxchg\n" | |
398aa668 | 360 | "ldrexd %1, %H1, [%3]\n" |
24b44a66 | 361 | "mov %0, #0\n" |
398aa668 WD |
362 | "teq %1, %4\n" |
363 | "teqeq %H1, %H4\n" | |
364 | "strexdeq %0, %5, %H5, [%3]" | |
365 | : "=&r" (res), "=&r" (oldval), "+Qo" (ptr->counter) | |
24b44a66 WD |
366 | : "r" (&ptr->counter), "r" (old), "r" (new) |
367 | : "cc"); | |
368 | } while (res); | |
369 | ||
370 | smp_mb(); | |
371 | ||
372 | return oldval; | |
373 | } | |
374 | ||
375 | static inline u64 atomic64_xchg(atomic64_t *ptr, u64 new) | |
376 | { | |
377 | u64 result; | |
378 | unsigned long tmp; | |
379 | ||
380 | smp_mb(); | |
381 | ||
382 | __asm__ __volatile__("@ atomic64_xchg\n" | |
398aa668 WD |
383 | "1: ldrexd %0, %H0, [%3]\n" |
384 | " strexd %1, %4, %H4, [%3]\n" | |
24b44a66 WD |
385 | " teq %1, #0\n" |
386 | " bne 1b" | |
398aa668 | 387 | : "=&r" (result), "=&r" (tmp), "+Qo" (ptr->counter) |
24b44a66 WD |
388 | : "r" (&ptr->counter), "r" (new) |
389 | : "cc"); | |
390 | ||
391 | smp_mb(); | |
392 | ||
393 | return result; | |
394 | } | |
395 | ||
396 | static inline u64 atomic64_dec_if_positive(atomic64_t *v) | |
397 | { | |
398 | u64 result; | |
399 | unsigned long tmp; | |
400 | ||
401 | smp_mb(); | |
402 | ||
403 | __asm__ __volatile__("@ atomic64_dec_if_positive\n" | |
398aa668 | 404 | "1: ldrexd %0, %H0, [%3]\n" |
24b44a66 WD |
405 | " subs %0, %0, #1\n" |
406 | " sbc %H0, %H0, #0\n" | |
407 | " teq %H0, #0\n" | |
408 | " bmi 2f\n" | |
398aa668 | 409 | " strexd %1, %0, %H0, [%3]\n" |
24b44a66 WD |
410 | " teq %1, #0\n" |
411 | " bne 1b\n" | |
412 | "2:" | |
398aa668 | 413 | : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) |
24b44a66 WD |
414 | : "r" (&v->counter) |
415 | : "cc"); | |
416 | ||
417 | smp_mb(); | |
418 | ||
419 | return result; | |
420 | } | |
421 | ||
422 | static inline int atomic64_add_unless(atomic64_t *v, u64 a, u64 u) | |
423 | { | |
424 | u64 val; | |
425 | unsigned long tmp; | |
426 | int ret = 1; | |
427 | ||
428 | smp_mb(); | |
429 | ||
430 | __asm__ __volatile__("@ atomic64_add_unless\n" | |
398aa668 WD |
431 | "1: ldrexd %0, %H0, [%4]\n" |
432 | " teq %0, %5\n" | |
433 | " teqeq %H0, %H5\n" | |
24b44a66 WD |
434 | " moveq %1, #0\n" |
435 | " beq 2f\n" | |
398aa668 WD |
436 | " adds %0, %0, %6\n" |
437 | " adc %H0, %H0, %H6\n" | |
438 | " strexd %2, %0, %H0, [%4]\n" | |
24b44a66 WD |
439 | " teq %2, #0\n" |
440 | " bne 1b\n" | |
441 | "2:" | |
398aa668 | 442 | : "=&r" (val), "+r" (ret), "=&r" (tmp), "+Qo" (v->counter) |
24b44a66 WD |
443 | : "r" (&v->counter), "r" (u), "r" (a) |
444 | : "cc"); | |
445 | ||
446 | if (ret) | |
447 | smp_mb(); | |
448 | ||
449 | return ret; | |
450 | } | |
451 | ||
452 | #define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0) | |
453 | #define atomic64_inc(v) atomic64_add(1LL, (v)) | |
454 | #define atomic64_inc_return(v) atomic64_add_return(1LL, (v)) | |
455 | #define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0) | |
456 | #define atomic64_sub_and_test(a, v) (atomic64_sub_return((a), (v)) == 0) | |
457 | #define atomic64_dec(v) atomic64_sub(1LL, (v)) | |
458 | #define atomic64_dec_return(v) atomic64_sub_return(1LL, (v)) | |
459 | #define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0) | |
460 | #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL) | |
461 | ||
462 | #else /* !CONFIG_GENERIC_ATOMIC64 */ | |
463 | #include <asm-generic/atomic64.h> | |
464 | #endif | |
72099ed2 | 465 | #include <asm-generic/atomic-long.h> |
1da177e4 LT |
466 | #endif |
467 | #endif |