xref: /linux/arch/powerpc/include/asm/atomic.h (revision 367b8112fe2ea5c39a7bb4d263dcdd9b612fae18)
1 #ifndef _ASM_POWERPC_ATOMIC_H_
2 #define _ASM_POWERPC_ATOMIC_H_
3 
4 /*
5  * PowerPC atomic operations
6  */
7 
8 typedef struct { int counter; } atomic_t;
9 
10 #ifdef __KERNEL__
11 #include <linux/compiler.h>
12 #include <asm/synch.h>
13 #include <asm/asm-compat.h>
14 #include <asm/system.h>
15 
16 #define ATOMIC_INIT(i)		{ (i) }
17 
18 static __inline__ int atomic_read(const atomic_t *v)
19 {
20 	int t;
21 
22 	__asm__ __volatile__("lwz%U1%X1 %0,%1" : "=r"(t) : "m"(v->counter));
23 
24 	return t;
25 }
26 
27 static __inline__ void atomic_set(atomic_t *v, int i)
28 {
29 	__asm__ __volatile__("stw%U0%X0 %1,%0" : "=m"(v->counter) : "r"(i));
30 }
31 
32 static __inline__ void atomic_add(int a, atomic_t *v)
33 {
34 	int t;
35 
36 	__asm__ __volatile__(
37 "1:	lwarx	%0,0,%3		# atomic_add\n\
38 	add	%0,%2,%0\n"
39 	PPC405_ERR77(0,%3)
40 "	stwcx.	%0,0,%3 \n\
41 	bne-	1b"
42 	: "=&r" (t), "+m" (v->counter)
43 	: "r" (a), "r" (&v->counter)
44 	: "cc");
45 }
46 
47 static __inline__ int atomic_add_return(int a, atomic_t *v)
48 {
49 	int t;
50 
51 	__asm__ __volatile__(
52 	LWSYNC_ON_SMP
53 "1:	lwarx	%0,0,%2		# atomic_add_return\n\
54 	add	%0,%1,%0\n"
55 	PPC405_ERR77(0,%2)
56 "	stwcx.	%0,0,%2 \n\
57 	bne-	1b"
58 	ISYNC_ON_SMP
59 	: "=&r" (t)
60 	: "r" (a), "r" (&v->counter)
61 	: "cc", "memory");
62 
63 	return t;
64 }
65 
66 #define atomic_add_negative(a, v)	(atomic_add_return((a), (v)) < 0)
67 
68 static __inline__ void atomic_sub(int a, atomic_t *v)
69 {
70 	int t;
71 
72 	__asm__ __volatile__(
73 "1:	lwarx	%0,0,%3		# atomic_sub\n\
74 	subf	%0,%2,%0\n"
75 	PPC405_ERR77(0,%3)
76 "	stwcx.	%0,0,%3 \n\
77 	bne-	1b"
78 	: "=&r" (t), "+m" (v->counter)
79 	: "r" (a), "r" (&v->counter)
80 	: "cc");
81 }
82 
83 static __inline__ int atomic_sub_return(int a, atomic_t *v)
84 {
85 	int t;
86 
87 	__asm__ __volatile__(
88 	LWSYNC_ON_SMP
89 "1:	lwarx	%0,0,%2		# atomic_sub_return\n\
90 	subf	%0,%1,%0\n"
91 	PPC405_ERR77(0,%2)
92 "	stwcx.	%0,0,%2 \n\
93 	bne-	1b"
94 	ISYNC_ON_SMP
95 	: "=&r" (t)
96 	: "r" (a), "r" (&v->counter)
97 	: "cc", "memory");
98 
99 	return t;
100 }
101 
102 static __inline__ void atomic_inc(atomic_t *v)
103 {
104 	int t;
105 
106 	__asm__ __volatile__(
107 "1:	lwarx	%0,0,%2		# atomic_inc\n\
108 	addic	%0,%0,1\n"
109 	PPC405_ERR77(0,%2)
110 "	stwcx.	%0,0,%2 \n\
111 	bne-	1b"
112 	: "=&r" (t), "+m" (v->counter)
113 	: "r" (&v->counter)
114 	: "cc");
115 }
116 
117 static __inline__ int atomic_inc_return(atomic_t *v)
118 {
119 	int t;
120 
121 	__asm__ __volatile__(
122 	LWSYNC_ON_SMP
123 "1:	lwarx	%0,0,%1		# atomic_inc_return\n\
124 	addic	%0,%0,1\n"
125 	PPC405_ERR77(0,%1)
126 "	stwcx.	%0,0,%1 \n\
127 	bne-	1b"
128 	ISYNC_ON_SMP
129 	: "=&r" (t)
130 	: "r" (&v->counter)
131 	: "cc", "memory");
132 
133 	return t;
134 }
135 
136 /*
137  * atomic_inc_and_test - increment and test
138  * @v: pointer of type atomic_t
139  *
140  * Atomically increments @v by 1
141  * and returns true if the result is zero, or false for all
142  * other cases.
143  */
144 #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
145 
146 static __inline__ void atomic_dec(atomic_t *v)
147 {
148 	int t;
149 
150 	__asm__ __volatile__(
151 "1:	lwarx	%0,0,%2		# atomic_dec\n\
152 	addic	%0,%0,-1\n"
153 	PPC405_ERR77(0,%2)\
154 "	stwcx.	%0,0,%2\n\
155 	bne-	1b"
156 	: "=&r" (t), "+m" (v->counter)
157 	: "r" (&v->counter)
158 	: "cc");
159 }
160 
161 static __inline__ int atomic_dec_return(atomic_t *v)
162 {
163 	int t;
164 
165 	__asm__ __volatile__(
166 	LWSYNC_ON_SMP
167 "1:	lwarx	%0,0,%1		# atomic_dec_return\n\
168 	addic	%0,%0,-1\n"
169 	PPC405_ERR77(0,%1)
170 "	stwcx.	%0,0,%1\n\
171 	bne-	1b"
172 	ISYNC_ON_SMP
173 	: "=&r" (t)
174 	: "r" (&v->counter)
175 	: "cc", "memory");
176 
177 	return t;
178 }
179 
180 #define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
181 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
182 
183 /**
184  * atomic_add_unless - add unless the number is a given value
185  * @v: pointer of type atomic_t
186  * @a: the amount to add to v...
187  * @u: ...unless v is equal to u.
188  *
189  * Atomically adds @a to @v, so long as it was not @u.
190  * Returns non-zero if @v was not @u, and zero otherwise.
191  */
192 static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
193 {
194 	int t;
195 
196 	__asm__ __volatile__ (
197 	LWSYNC_ON_SMP
198 "1:	lwarx	%0,0,%1		# atomic_add_unless\n\
199 	cmpw	0,%0,%3 \n\
200 	beq-	2f \n\
201 	add	%0,%2,%0 \n"
202 	PPC405_ERR77(0,%2)
203 "	stwcx.	%0,0,%1 \n\
204 	bne-	1b \n"
205 	ISYNC_ON_SMP
206 "	subf	%0,%2,%0 \n\
207 2:"
208 	: "=&r" (t)
209 	: "r" (&v->counter), "r" (a), "r" (u)
210 	: "cc", "memory");
211 
212 	return t != u;
213 }
214 
215 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
216 
217 #define atomic_sub_and_test(a, v)	(atomic_sub_return((a), (v)) == 0)
218 #define atomic_dec_and_test(v)		(atomic_dec_return((v)) == 0)
219 
220 /*
221  * Atomically test *v and decrement if it is greater than 0.
222  * The function returns the old value of *v minus 1, even if
223  * the atomic variable, v, was not decremented.
224  */
225 static __inline__ int atomic_dec_if_positive(atomic_t *v)
226 {
227 	int t;
228 
229 	__asm__ __volatile__(
230 	LWSYNC_ON_SMP
231 "1:	lwarx	%0,0,%1		# atomic_dec_if_positive\n\
232 	cmpwi	%0,1\n\
233 	addi	%0,%0,-1\n\
234 	blt-	2f\n"
235 	PPC405_ERR77(0,%1)
236 "	stwcx.	%0,0,%1\n\
237 	bne-	1b"
238 	ISYNC_ON_SMP
239 	"\n\
240 2:"	: "=&b" (t)
241 	: "r" (&v->counter)
242 	: "cc", "memory");
243 
244 	return t;
245 }
246 
247 #define smp_mb__before_atomic_dec()     smp_mb()
248 #define smp_mb__after_atomic_dec()      smp_mb()
249 #define smp_mb__before_atomic_inc()     smp_mb()
250 #define smp_mb__after_atomic_inc()      smp_mb()
251 
252 #ifdef __powerpc64__
253 
254 typedef struct { long counter; } atomic64_t;
255 
256 #define ATOMIC64_INIT(i)	{ (i) }
257 
258 static __inline__ long atomic64_read(const atomic64_t *v)
259 {
260 	long t;
261 
262 	__asm__ __volatile__("ld%U1%X1 %0,%1" : "=r"(t) : "m"(v->counter));
263 
264 	return t;
265 }
266 
267 static __inline__ void atomic64_set(atomic64_t *v, long i)
268 {
269 	__asm__ __volatile__("std%U0%X0 %1,%0" : "=m"(v->counter) : "r"(i));
270 }
271 
272 static __inline__ void atomic64_add(long a, atomic64_t *v)
273 {
274 	long t;
275 
276 	__asm__ __volatile__(
277 "1:	ldarx	%0,0,%3		# atomic64_add\n\
278 	add	%0,%2,%0\n\
279 	stdcx.	%0,0,%3 \n\
280 	bne-	1b"
281 	: "=&r" (t), "+m" (v->counter)
282 	: "r" (a), "r" (&v->counter)
283 	: "cc");
284 }
285 
286 static __inline__ long atomic64_add_return(long a, atomic64_t *v)
287 {
288 	long t;
289 
290 	__asm__ __volatile__(
291 	LWSYNC_ON_SMP
292 "1:	ldarx	%0,0,%2		# atomic64_add_return\n\
293 	add	%0,%1,%0\n\
294 	stdcx.	%0,0,%2 \n\
295 	bne-	1b"
296 	ISYNC_ON_SMP
297 	: "=&r" (t)
298 	: "r" (a), "r" (&v->counter)
299 	: "cc", "memory");
300 
301 	return t;
302 }
303 
304 #define atomic64_add_negative(a, v)	(atomic64_add_return((a), (v)) < 0)
305 
306 static __inline__ void atomic64_sub(long a, atomic64_t *v)
307 {
308 	long t;
309 
310 	__asm__ __volatile__(
311 "1:	ldarx	%0,0,%3		# atomic64_sub\n\
312 	subf	%0,%2,%0\n\
313 	stdcx.	%0,0,%3 \n\
314 	bne-	1b"
315 	: "=&r" (t), "+m" (v->counter)
316 	: "r" (a), "r" (&v->counter)
317 	: "cc");
318 }
319 
320 static __inline__ long atomic64_sub_return(long a, atomic64_t *v)
321 {
322 	long t;
323 
324 	__asm__ __volatile__(
325 	LWSYNC_ON_SMP
326 "1:	ldarx	%0,0,%2		# atomic64_sub_return\n\
327 	subf	%0,%1,%0\n\
328 	stdcx.	%0,0,%2 \n\
329 	bne-	1b"
330 	ISYNC_ON_SMP
331 	: "=&r" (t)
332 	: "r" (a), "r" (&v->counter)
333 	: "cc", "memory");
334 
335 	return t;
336 }
337 
338 static __inline__ void atomic64_inc(atomic64_t *v)
339 {
340 	long t;
341 
342 	__asm__ __volatile__(
343 "1:	ldarx	%0,0,%2		# atomic64_inc\n\
344 	addic	%0,%0,1\n\
345 	stdcx.	%0,0,%2 \n\
346 	bne-	1b"
347 	: "=&r" (t), "+m" (v->counter)
348 	: "r" (&v->counter)
349 	: "cc");
350 }
351 
352 static __inline__ long atomic64_inc_return(atomic64_t *v)
353 {
354 	long t;
355 
356 	__asm__ __volatile__(
357 	LWSYNC_ON_SMP
358 "1:	ldarx	%0,0,%1		# atomic64_inc_return\n\
359 	addic	%0,%0,1\n\
360 	stdcx.	%0,0,%1 \n\
361 	bne-	1b"
362 	ISYNC_ON_SMP
363 	: "=&r" (t)
364 	: "r" (&v->counter)
365 	: "cc", "memory");
366 
367 	return t;
368 }
369 
370 /*
371  * atomic64_inc_and_test - increment and test
372  * @v: pointer of type atomic64_t
373  *
374  * Atomically increments @v by 1
375  * and returns true if the result is zero, or false for all
376  * other cases.
377  */
378 #define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
379 
380 static __inline__ void atomic64_dec(atomic64_t *v)
381 {
382 	long t;
383 
384 	__asm__ __volatile__(
385 "1:	ldarx	%0,0,%2		# atomic64_dec\n\
386 	addic	%0,%0,-1\n\
387 	stdcx.	%0,0,%2\n\
388 	bne-	1b"
389 	: "=&r" (t), "+m" (v->counter)
390 	: "r" (&v->counter)
391 	: "cc");
392 }
393 
394 static __inline__ long atomic64_dec_return(atomic64_t *v)
395 {
396 	long t;
397 
398 	__asm__ __volatile__(
399 	LWSYNC_ON_SMP
400 "1:	ldarx	%0,0,%1		# atomic64_dec_return\n\
401 	addic	%0,%0,-1\n\
402 	stdcx.	%0,0,%1\n\
403 	bne-	1b"
404 	ISYNC_ON_SMP
405 	: "=&r" (t)
406 	: "r" (&v->counter)
407 	: "cc", "memory");
408 
409 	return t;
410 }
411 
412 #define atomic64_sub_and_test(a, v)	(atomic64_sub_return((a), (v)) == 0)
413 #define atomic64_dec_and_test(v)	(atomic64_dec_return((v)) == 0)
414 
415 /*
416  * Atomically test *v and decrement if it is greater than 0.
417  * The function returns the old value of *v minus 1.
418  */
419 static __inline__ long atomic64_dec_if_positive(atomic64_t *v)
420 {
421 	long t;
422 
423 	__asm__ __volatile__(
424 	LWSYNC_ON_SMP
425 "1:	ldarx	%0,0,%1		# atomic64_dec_if_positive\n\
426 	addic.	%0,%0,-1\n\
427 	blt-	2f\n\
428 	stdcx.	%0,0,%1\n\
429 	bne-	1b"
430 	ISYNC_ON_SMP
431 	"\n\
432 2:"	: "=&r" (t)
433 	: "r" (&v->counter)
434 	: "cc", "memory");
435 
436 	return t;
437 }
438 
439 #define atomic64_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
440 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
441 
442 /**
443  * atomic64_add_unless - add unless the number is a given value
444  * @v: pointer of type atomic64_t
445  * @a: the amount to add to v...
446  * @u: ...unless v is equal to u.
447  *
448  * Atomically adds @a to @v, so long as it was not @u.
449  * Returns non-zero if @v was not @u, and zero otherwise.
450  */
451 static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
452 {
453 	long t;
454 
455 	__asm__ __volatile__ (
456 	LWSYNC_ON_SMP
457 "1:	ldarx	%0,0,%1		# atomic_add_unless\n\
458 	cmpd	0,%0,%3 \n\
459 	beq-	2f \n\
460 	add	%0,%2,%0 \n"
461 "	stdcx.	%0,0,%1 \n\
462 	bne-	1b \n"
463 	ISYNC_ON_SMP
464 "	subf	%0,%2,%0 \n\
465 2:"
466 	: "=&r" (t)
467 	: "r" (&v->counter), "r" (a), "r" (u)
468 	: "cc", "memory");
469 
470 	return t != u;
471 }
472 
473 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
474 
475 #endif /* __powerpc64__ */
476 
477 #include <asm-generic/atomic.h>
478 #endif /* __KERNEL__ */
479 #endif /* _ASM_POWERPC_ATOMIC_H_ */
480