xref: /freebsd/sys/powerpc/include/atomic.h (revision 640235e2c2ba32947f7c59d168437ffa1280f1e6)
1 /*-
2  * Copyright (c) 2008 Marcel Moolenaar
3  * Copyright (c) 2001 Benno Rice
4  * Copyright (c) 2001 David E. O'Brien
5  * Copyright (c) 1998 Doug Rabson
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 #ifndef _MACHINE_ATOMIC_H_
33 #define	_MACHINE_ATOMIC_H_
34 
35 #ifndef _SYS_CDEFS_H_
36 #error this file needs sys/cdefs.h as a prerequisite
37 #endif
38 
39 /*
40  * The __ATOMIC_REL/ACQ() macros provide memory barriers only in conjunction
41  * with the atomic lXarx/stXcx. sequences below. They are not exposed outside
42  * of this file. See also Appendix B.2 of Book II of the architecture manual.
43  *
44  * Note that not all Book-E processors accept the light-weight sync variant.
45  * In particular, early models of E500 cores are known to wedge. Bank on all
46  * 64-bit capable CPUs to accept lwsync properly and pressimize 32-bit CPUs
47  * to use the heavier-weight sync.
48  */
49 
50 #ifdef __powerpc64__
51 #define mb()		__asm __volatile("sync" : : : "memory")
52 #define rmb()		__asm __volatile("lwsync" : : : "memory")
53 #define wmb()		__asm __volatile("lwsync" : : : "memory")
54 #define __ATOMIC_REL()	__asm __volatile("lwsync" : : : "memory")
55 #define __ATOMIC_ACQ()	__asm __volatile("isync" : : : "memory")
56 #else
57 #define mb()		__asm __volatile("sync" : : : "memory")
58 #define rmb()		__asm __volatile("sync" : : : "memory")
59 #define wmb()		__asm __volatile("sync" : : : "memory")
60 #define __ATOMIC_REL()	__asm __volatile("sync" : : : "memory")
61 #define __ATOMIC_ACQ()	__asm __volatile("isync" : : : "memory")
62 #endif
63 
64 static __inline void
65 powerpc_lwsync(void)
66 {
67 
68 #ifdef __powerpc64__
69 	__asm __volatile("lwsync" : : : "memory");
70 #else
71 	__asm __volatile("sync" : : : "memory");
72 #endif
73 }
74 
75 /*
76  * atomic_add(p, v)
77  * { *p += v; }
78  */
79 
80 #define __atomic_add_int(p, v, t)				\
81     __asm __volatile(						\
82 	"1:	lwarx	%0, 0, %2\n"				\
83 	"	add	%0, %3, %0\n"				\
84 	"	stwcx.	%0, 0, %2\n"				\
85 	"	bne-	1b\n"					\
86 	: "=&r" (t), "=m" (*p)					\
87 	: "r" (p), "r" (v), "m" (*p)				\
88 	: "cr0", "memory")					\
89     /* __atomic_add_int */
90 
91 #ifdef __powerpc64__
92 #define __atomic_add_long(p, v, t)				\
93     __asm __volatile(						\
94 	"1:	ldarx	%0, 0, %2\n"				\
95 	"	add	%0, %3, %0\n"				\
96 	"	stdcx.	%0, 0, %2\n"				\
97 	"	bne-	1b\n"					\
98 	: "=&r" (t), "=m" (*p)					\
99 	: "r" (p), "r" (v), "m" (*p)				\
100 	: "cr0", "memory")					\
101     /* __atomic_add_long */
102 #else
103 #define	__atomic_add_long(p, v, t)				\
104     __asm __volatile(						\
105 	"1:	lwarx	%0, 0, %2\n"				\
106 	"	add	%0, %3, %0\n"				\
107 	"	stwcx.	%0, 0, %2\n"				\
108 	"	bne-	1b\n"					\
109 	: "=&r" (t), "=m" (*p)					\
110 	: "r" (p), "r" (v), "m" (*p)				\
111 	: "cr0", "memory")					\
112     /* __atomic_add_long */
113 #endif
114 
115 #define	_ATOMIC_ADD(type)					\
116     static __inline void					\
117     atomic_add_##type(volatile u_##type *p, u_##type v) {	\
118 	u_##type t;						\
119 	__atomic_add_##type(p, v, t);				\
120     }								\
121 								\
122     static __inline void					\
123     atomic_add_acq_##type(volatile u_##type *p, u_##type v) {	\
124 	u_##type t;						\
125 	__atomic_add_##type(p, v, t);				\
126 	__ATOMIC_ACQ();						\
127     }								\
128 								\
129     static __inline void					\
130     atomic_add_rel_##type(volatile u_##type *p, u_##type v) {	\
131 	u_##type t;						\
132 	__ATOMIC_REL();						\
133 	__atomic_add_##type(p, v, t);				\
134     }								\
135     /* _ATOMIC_ADD */
136 
137 _ATOMIC_ADD(int)
138 _ATOMIC_ADD(long)
139 
140 #define	atomic_add_32		atomic_add_int
141 #define	atomic_add_acq_32	atomic_add_acq_int
142 #define	atomic_add_rel_32	atomic_add_rel_int
143 
144 #ifdef __powerpc64__
145 #define	atomic_add_64		atomic_add_long
146 #define	atomic_add_acq_64	atomic_add_acq_long
147 #define	atomic_add_rel_64	atomic_add_rel_long
148 
149 #define	atomic_add_ptr		atomic_add_long
150 #define	atomic_add_acq_ptr	atomic_add_acq_long
151 #define	atomic_add_rel_ptr	atomic_add_rel_long
152 #else
153 #define	atomic_add_ptr		atomic_add_int
154 #define	atomic_add_acq_ptr	atomic_add_acq_int
155 #define	atomic_add_rel_ptr	atomic_add_rel_int
156 #endif
157 #undef _ATOMIC_ADD
158 #undef __atomic_add_long
159 #undef __atomic_add_int
160 
161 /*
162  * atomic_clear(p, v)
163  * { *p &= ~v; }
164  */
165 
166 #define __atomic_clear_int(p, v, t)				\
167     __asm __volatile(						\
168 	"1:	lwarx	%0, 0, %2\n"				\
169 	"	andc	%0, %0, %3\n"				\
170 	"	stwcx.	%0, 0, %2\n"				\
171 	"	bne-	1b\n"					\
172 	: "=&r" (t), "=m" (*p)					\
173 	: "r" (p), "r" (v), "m" (*p)				\
174 	: "cr0", "memory")					\
175     /* __atomic_clear_int */
176 
177 #ifdef __powerpc64__
178 #define __atomic_clear_long(p, v, t)				\
179     __asm __volatile(						\
180 	"1:	ldarx	%0, 0, %2\n"				\
181 	"	andc	%0, %0, %3\n"				\
182 	"	stdcx.	%0, 0, %2\n"				\
183 	"	bne-	1b\n"					\
184 	: "=&r" (t), "=m" (*p)					\
185 	: "r" (p), "r" (v), "m" (*p)				\
186 	: "cr0", "memory")					\
187     /* __atomic_clear_long */
188 #else
189 #define	__atomic_clear_long(p, v, t)				\
190     __asm __volatile(						\
191 	"1:	lwarx	%0, 0, %2\n"				\
192 	"	andc	%0, %0, %3\n"				\
193 	"	stwcx.	%0, 0, %2\n"				\
194 	"	bne-	1b\n"					\
195 	: "=&r" (t), "=m" (*p)					\
196 	: "r" (p), "r" (v), "m" (*p)				\
197 	: "cr0", "memory")					\
198     /* __atomic_clear_long */
199 #endif
200 
201 #define	_ATOMIC_CLEAR(type)					\
202     static __inline void					\
203     atomic_clear_##type(volatile u_##type *p, u_##type v) {	\
204 	u_##type t;						\
205 	__atomic_clear_##type(p, v, t);				\
206     }								\
207 								\
208     static __inline void					\
209     atomic_clear_acq_##type(volatile u_##type *p, u_##type v) {	\
210 	u_##type t;						\
211 	__atomic_clear_##type(p, v, t);				\
212 	__ATOMIC_ACQ();						\
213     }								\
214 								\
215     static __inline void					\
216     atomic_clear_rel_##type(volatile u_##type *p, u_##type v) {	\
217 	u_##type t;						\
218 	__ATOMIC_REL();						\
219 	__atomic_clear_##type(p, v, t);				\
220     }								\
221     /* _ATOMIC_CLEAR */
222 
223 
224 _ATOMIC_CLEAR(int)
225 _ATOMIC_CLEAR(long)
226 
227 #define	atomic_clear_32		atomic_clear_int
228 #define	atomic_clear_acq_32	atomic_clear_acq_int
229 #define	atomic_clear_rel_32	atomic_clear_rel_int
230 
231 #ifdef __powerpc64__
232 #define	atomic_clear_64		atomic_clear_long
233 #define	atomic_clear_acq_64	atomic_clear_acq_long
234 #define	atomic_clear_rel_64	atomic_clear_rel_long
235 
236 #define	atomic_clear_ptr	atomic_clear_long
237 #define	atomic_clear_acq_ptr	atomic_clear_acq_long
238 #define	atomic_clear_rel_ptr	atomic_clear_rel_long
239 #else
240 #define	atomic_clear_ptr	atomic_clear_int
241 #define	atomic_clear_acq_ptr	atomic_clear_acq_int
242 #define	atomic_clear_rel_ptr	atomic_clear_rel_int
243 #endif
244 #undef _ATOMIC_CLEAR
245 #undef __atomic_clear_long
246 #undef __atomic_clear_int
247 
248 /*
249  * atomic_cmpset(p, o, n)
250  */
251 /* TODO -- see below */
252 
253 /*
254  * atomic_load_acq(p)
255  */
256 /* TODO -- see below */
257 
258 /*
259  * atomic_readandclear(p)
260  */
261 /* TODO -- see below */
262 
263 /*
264  * atomic_set(p, v)
265  * { *p |= v; }
266  */
267 
268 #define __atomic_set_int(p, v, t)				\
269     __asm __volatile(						\
270 	"1:	lwarx	%0, 0, %2\n"				\
271 	"	or	%0, %3, %0\n"				\
272 	"	stwcx.	%0, 0, %2\n"				\
273 	"	bne-	1b\n"					\
274 	: "=&r" (t), "=m" (*p)					\
275 	: "r" (p), "r" (v), "m" (*p)				\
276 	: "cr0", "memory")					\
277     /* __atomic_set_int */
278 
279 #ifdef __powerpc64__
280 #define __atomic_set_long(p, v, t)				\
281     __asm __volatile(						\
282 	"1:	ldarx	%0, 0, %2\n"				\
283 	"	or	%0, %3, %0\n"				\
284 	"	stdcx.	%0, 0, %2\n"				\
285 	"	bne-	1b\n"					\
286 	: "=&r" (t), "=m" (*p)					\
287 	: "r" (p), "r" (v), "m" (*p)				\
288 	: "cr0", "memory")					\
289     /* __atomic_set_long */
290 #else
291 #define	__atomic_set_long(p, v, t)				\
292     __asm __volatile(						\
293 	"1:	lwarx	%0, 0, %2\n"				\
294 	"	or	%0, %3, %0\n"				\
295 	"	stwcx.	%0, 0, %2\n"				\
296 	"	bne-	1b\n"					\
297 	: "=&r" (t), "=m" (*p)					\
298 	: "r" (p), "r" (v), "m" (*p)				\
299 	: "cr0", "memory")					\
300     /* __atomic_set_long */
301 #endif
302 
303 #define	_ATOMIC_SET(type)					\
304     static __inline void					\
305     atomic_set_##type(volatile u_##type *p, u_##type v) {	\
306 	u_##type t;						\
307 	__atomic_set_##type(p, v, t);				\
308     }								\
309 								\
310     static __inline void					\
311     atomic_set_acq_##type(volatile u_##type *p, u_##type v) {	\
312 	u_##type t;						\
313 	__atomic_set_##type(p, v, t);				\
314 	__ATOMIC_ACQ();						\
315     }								\
316 								\
317     static __inline void					\
318     atomic_set_rel_##type(volatile u_##type *p, u_##type v) {	\
319 	u_##type t;						\
320 	__ATOMIC_REL();						\
321 	__atomic_set_##type(p, v, t);				\
322     }								\
323     /* _ATOMIC_SET */
324 
325 _ATOMIC_SET(int)
326 _ATOMIC_SET(long)
327 
328 #define	atomic_set_32		atomic_set_int
329 #define	atomic_set_acq_32	atomic_set_acq_int
330 #define	atomic_set_rel_32	atomic_set_rel_int
331 
332 #ifdef __powerpc64__
333 #define	atomic_set_64		atomic_set_long
334 #define	atomic_set_acq_64	atomic_set_acq_long
335 #define	atomic_set_rel_64	atomic_set_rel_long
336 
337 #define	atomic_set_ptr		atomic_set_long
338 #define	atomic_set_acq_ptr	atomic_set_acq_long
339 #define	atomic_set_rel_ptr	atomic_set_rel_long
340 #else
341 #define	atomic_set_ptr		atomic_set_int
342 #define	atomic_set_acq_ptr	atomic_set_acq_int
343 #define	atomic_set_rel_ptr	atomic_set_rel_int
344 #endif
345 #undef _ATOMIC_SET
346 #undef __atomic_set_long
347 #undef __atomic_set_int
348 
349 /*
350  * atomic_subtract(p, v)
351  * { *p -= v; }
352  */
353 
354 #define __atomic_subtract_int(p, v, t)				\
355     __asm __volatile(						\
356 	"1:	lwarx	%0, 0, %2\n"				\
357 	"	subf	%0, %3, %0\n"				\
358 	"	stwcx.	%0, 0, %2\n"				\
359 	"	bne-	1b\n"					\
360 	: "=&r" (t), "=m" (*p)					\
361 	: "r" (p), "r" (v), "m" (*p)				\
362 	: "cr0", "memory")					\
363     /* __atomic_subtract_int */
364 
365 #ifdef __powerpc64__
366 #define __atomic_subtract_long(p, v, t)				\
367     __asm __volatile(						\
368 	"1:	ldarx	%0, 0, %2\n"				\
369 	"	subf	%0, %3, %0\n"				\
370 	"	stdcx.	%0, 0, %2\n"				\
371 	"	bne-	1b\n"					\
372 	: "=&r" (t), "=m" (*p)					\
373 	: "r" (p), "r" (v), "m" (*p)				\
374 	: "cr0", "memory")					\
375     /* __atomic_subtract_long */
376 #else
377 #define	__atomic_subtract_long(p, v, t)				\
378     __asm __volatile(						\
379 	"1:	lwarx	%0, 0, %2\n"				\
380 	"	subf	%0, %3, %0\n"				\
381 	"	stwcx.	%0, 0, %2\n"				\
382 	"	bne-	1b\n"					\
383 	: "=&r" (t), "=m" (*p)					\
384 	: "r" (p), "r" (v), "m" (*p)				\
385 	: "cr0", "memory")					\
386     /* __atomic_subtract_long */
387 #endif
388 
389 #define	_ATOMIC_SUBTRACT(type)						\
390     static __inline void						\
391     atomic_subtract_##type(volatile u_##type *p, u_##type v) {		\
392 	u_##type t;							\
393 	__atomic_subtract_##type(p, v, t);				\
394     }									\
395 									\
396     static __inline void						\
397     atomic_subtract_acq_##type(volatile u_##type *p, u_##type v) {	\
398 	u_##type t;							\
399 	__atomic_subtract_##type(p, v, t);				\
400 	__ATOMIC_ACQ();							\
401     }									\
402 									\
403     static __inline void						\
404     atomic_subtract_rel_##type(volatile u_##type *p, u_##type v) {	\
405 	u_##type t;							\
406 	__ATOMIC_REL();							\
407 	__atomic_subtract_##type(p, v, t);				\
408     }									\
409     /* _ATOMIC_SUBTRACT */
410 
411 _ATOMIC_SUBTRACT(int)
412 _ATOMIC_SUBTRACT(long)
413 
414 #define	atomic_subtract_32	atomic_subtract_int
415 #define	atomic_subtract_acq_32	atomic_subtract_acq_int
416 #define	atomic_subtract_rel_32	atomic_subtract_rel_int
417 
418 #ifdef __powerpc64__
419 #define	atomic_subtract_64	atomic_subtract_long
420 #define	atomic_subtract_acq_64	atomic_subract_acq_long
421 #define	atomic_subtract_rel_64	atomic_subtract_rel_long
422 
423 #define	atomic_subtract_ptr	atomic_subtract_long
424 #define	atomic_subtract_acq_ptr	atomic_subtract_acq_long
425 #define	atomic_subtract_rel_ptr	atomic_subtract_rel_long
426 #else
427 #define	atomic_subtract_ptr	atomic_subtract_int
428 #define	atomic_subtract_acq_ptr	atomic_subtract_acq_int
429 #define	atomic_subtract_rel_ptr	atomic_subtract_rel_int
430 #endif
431 #undef _ATOMIC_SUBTRACT
432 #undef __atomic_subtract_long
433 #undef __atomic_subtract_int
434 
435 /*
436  * atomic_store_rel(p, v)
437  */
438 /* TODO -- see below */
439 
440 /*
441  * Old/original implementations that still need revisiting.
442  */
443 
444 static __inline u_int
445 atomic_readandclear_int(volatile u_int *addr)
446 {
447 	u_int result,temp;
448 
449 #ifdef __GNUCLIKE_ASM
450 	__asm __volatile (
451 		"\tsync\n"			/* drain writes */
452 		"1:\tlwarx %0, 0, %3\n\t"	/* load old value */
453 		"li %1, 0\n\t"			/* load new value */
454 		"stwcx. %1, 0, %3\n\t"      	/* attempt to store */
455 		"bne- 1b\n\t"			/* spin if failed */
456 		: "=&r"(result), "=&r"(temp), "=m" (*addr)
457 		: "r" (addr), "m" (*addr)
458 		: "cr0", "memory");
459 #endif
460 
461 	return (result);
462 }
463 
464 #ifdef __powerpc64__
465 static __inline u_long
466 atomic_readandclear_long(volatile u_long *addr)
467 {
468 	u_long result,temp;
469 
470 #ifdef __GNUCLIKE_ASM
471 	__asm __volatile (
472 		"\tsync\n"			/* drain writes */
473 		"1:\tldarx %0, 0, %3\n\t"	/* load old value */
474 		"li %1, 0\n\t"			/* load new value */
475 		"stdcx. %1, 0, %3\n\t"      	/* attempt to store */
476 		"bne- 1b\n\t"			/* spin if failed */
477 		: "=&r"(result), "=&r"(temp), "=m" (*addr)
478 		: "r" (addr), "m" (*addr)
479 		: "cr0", "memory");
480 #endif
481 
482 	return (result);
483 }
484 #endif
485 
486 #define	atomic_readandclear_32		atomic_readandclear_int
487 
488 #ifdef __powerpc64__
489 #define	atomic_readandclear_64		atomic_readandclear_long
490 
491 #define	atomic_readandclear_ptr		atomic_readandclear_long
492 #else
493 static __inline u_long
494 atomic_readandclear_long(volatile u_long *addr)
495 {
496 
497 	return ((u_long)atomic_readandclear_int((volatile u_int *)addr));
498 }
499 
500 #define	atomic_readandclear_ptr		atomic_readandclear_int
501 #endif
502 
503 /*
504  * We assume that a = b will do atomic loads and stores.
505  */
506 #define	ATOMIC_STORE_LOAD(TYPE)					\
507 static __inline u_##TYPE					\
508 atomic_load_acq_##TYPE(volatile u_##TYPE *p)			\
509 {								\
510 	u_##TYPE v;						\
511 								\
512 	v = *p;							\
513 	mb();							\
514 	return (v);						\
515 }								\
516 								\
517 static __inline void						\
518 atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)	\
519 {								\
520 								\
521 	powerpc_lwsync();					\
522 	*p = v;							\
523 }
524 
525 ATOMIC_STORE_LOAD(int)
526 
527 #define	atomic_load_acq_32	atomic_load_acq_int
528 #define	atomic_store_rel_32	atomic_store_rel_int
529 
530 #ifdef __powerpc64__
531 ATOMIC_STORE_LOAD(long)
532 
533 #define	atomic_load_acq_64	atomic_load_acq_long
534 #define	atomic_store_rel_64	atomic_store_rel_long
535 
536 #define	atomic_load_acq_ptr	atomic_load_acq_long
537 #define	atomic_store_rel_ptr	atomic_store_rel_long
538 #else
539 static __inline u_long
540 atomic_load_acq_long(volatile u_long *addr)
541 {
542 
543 	return ((u_long)atomic_load_acq_int((volatile u_int *)addr));
544 }
545 
546 static __inline void
547 atomic_store_rel_long(volatile u_long *addr, u_long val)
548 {
549 
550 	atomic_store_rel_int((volatile u_int *)addr, (u_int)val);
551 }
552 
553 #define	atomic_load_acq_ptr	atomic_load_acq_int
554 #define	atomic_store_rel_ptr	atomic_store_rel_int
555 #endif
556 #undef ATOMIC_STORE_LOAD
557 
558 /*
559  * Atomically compare the value stored at *p with cmpval and if the
560  * two values are equal, update the value of *p with newval. Returns
561  * zero if the compare failed, nonzero otherwise.
562  */
563 static __inline int
564 atomic_cmpset_int(volatile u_int* p, u_int cmpval, u_int newval)
565 {
566 	int	ret;
567 
568 #ifdef __GNUCLIKE_ASM
569 	__asm __volatile (
570 		"1:\tlwarx %0, 0, %2\n\t"	/* load old value */
571 		"cmplw %3, %0\n\t"		/* compare */
572 		"bne 2f\n\t"			/* exit if not equal */
573 		"stwcx. %4, 0, %2\n\t"      	/* attempt to store */
574 		"bne- 1b\n\t"			/* spin if failed */
575 		"li %0, 1\n\t"			/* success - retval = 1 */
576 		"b 3f\n\t"			/* we've succeeded */
577 		"2:\n\t"
578 		"stwcx. %0, 0, %2\n\t"       	/* clear reservation (74xx) */
579 		"li %0, 0\n\t"			/* failure - retval = 0 */
580 		"3:\n\t"
581 		: "=&r" (ret), "=m" (*p)
582 		: "r" (p), "r" (cmpval), "r" (newval), "m" (*p)
583 		: "cr0", "memory");
584 #endif
585 
586 	return (ret);
587 }
588 static __inline int
589 atomic_cmpset_long(volatile u_long* p, u_long cmpval, u_long newval)
590 {
591 	int ret;
592 
593 #ifdef __GNUCLIKE_ASM
594 	__asm __volatile (
595 	    #ifdef __powerpc64__
596 		"1:\tldarx %0, 0, %2\n\t"	/* load old value */
597 		"cmpld %3, %0\n\t"		/* compare */
598 		"bne 2f\n\t"			/* exit if not equal */
599 		"stdcx. %4, 0, %2\n\t"		/* attempt to store */
600 	    #else
601 		"1:\tlwarx %0, 0, %2\n\t"	/* load old value */
602 		"cmplw %3, %0\n\t"		/* compare */
603 		"bne 2f\n\t"			/* exit if not equal */
604 		"stwcx. %4, 0, %2\n\t"		/* attempt to store */
605 	    #endif
606 		"bne- 1b\n\t"			/* spin if failed */
607 		"li %0, 1\n\t"			/* success - retval = 1 */
608 		"b 3f\n\t"			/* we've succeeded */
609 		"2:\n\t"
610 	    #ifdef __powerpc64__
611 		"stdcx. %0, 0, %2\n\t"		/* clear reservation (74xx) */
612 	    #else
613 		"stwcx. %0, 0, %2\n\t"		/* clear reservation (74xx) */
614 	    #endif
615 		"li %0, 0\n\t"			/* failure - retval = 0 */
616 		"3:\n\t"
617 		: "=&r" (ret), "=m" (*p)
618 		: "r" (p), "r" (cmpval), "r" (newval), "m" (*p)
619 		: "cr0", "memory");
620 #endif
621 
622 	return (ret);
623 }
624 
625 static __inline int
626 atomic_cmpset_acq_int(volatile u_int *p, u_int cmpval, u_int newval)
627 {
628 	int retval;
629 
630 	retval = atomic_cmpset_int(p, cmpval, newval);
631 	__ATOMIC_ACQ();
632 	return (retval);
633 }
634 
635 static __inline int
636 atomic_cmpset_rel_int(volatile u_int *p, u_int cmpval, u_int newval)
637 {
638 	__ATOMIC_REL();
639 	return (atomic_cmpset_int(p, cmpval, newval));
640 }
641 
642 static __inline int
643 atomic_cmpset_acq_long(volatile u_long *p, u_long cmpval, u_long newval)
644 {
645 	u_long retval;
646 
647 	retval = atomic_cmpset_long(p, cmpval, newval);
648 	__ATOMIC_ACQ();
649 	return (retval);
650 }
651 
652 static __inline int
653 atomic_cmpset_rel_long(volatile u_long *p, u_long cmpval, u_long newval)
654 {
655 	__ATOMIC_REL();
656 	return (atomic_cmpset_long(p, cmpval, newval));
657 }
658 
659 #define	atomic_cmpset_32	atomic_cmpset_int
660 #define	atomic_cmpset_acq_32	atomic_cmpset_acq_int
661 #define	atomic_cmpset_rel_32	atomic_cmpset_rel_int
662 
663 #ifdef __powerpc64__
664 #define	atomic_cmpset_64	atomic_cmpset_long
665 #define	atomic_cmpset_acq_64	atomic_cmpset_acq_long
666 #define	atomic_cmpset_rel_64	atomic_cmpset_rel_long
667 
668 #define	atomic_cmpset_ptr	atomic_cmpset_long
669 #define	atomic_cmpset_acq_ptr	atomic_cmpset_acq_long
670 #define	atomic_cmpset_rel_ptr	atomic_cmpset_rel_long
671 #else
672 #define	atomic_cmpset_ptr	atomic_cmpset_int
673 #define	atomic_cmpset_acq_ptr	atomic_cmpset_acq_int
674 #define	atomic_cmpset_rel_ptr	atomic_cmpset_rel_int
675 #endif
676 
677 static __inline u_int
678 atomic_fetchadd_int(volatile u_int *p, u_int v)
679 {
680 	u_int value;
681 
682 	do {
683 		value = *p;
684 	} while (!atomic_cmpset_int(p, value, value + v));
685 	return (value);
686 }
687 
688 static __inline u_long
689 atomic_fetchadd_long(volatile u_long *p, u_long v)
690 {
691 	u_long value;
692 
693 	do {
694 		value = *p;
695 	} while (!atomic_cmpset_long(p, value, value + v));
696 	return (value);
697 }
698 
699 static __inline u_int
700 atomic_swap_32(volatile u_int *p, u_int v)
701 {
702 	u_int prev;
703 
704 	__asm __volatile(
705 	"1:	lwarx	%0,0,%2\n"
706 	"	stwcx.	%3,0,%2\n"
707 	"	bne-	1b\n"
708 	: "=&r" (prev), "+m" (*(volatile u_int *)p)
709 	: "r" (p), "r" (v)
710 	: "cr0", "memory");
711 
712 	return (prev);
713 }
714 
715 #ifdef __powerpc64__
716 static __inline u_long
717 atomic_swap_64(volatile u_long *p, u_long v)
718 {
719 	u_long prev;
720 
721 	__asm __volatile(
722 	"1:	ldarx	%0,0,%2\n"
723 	"	stdcx.	%3,0,%2\n"
724 	"	bne-	1b\n"
725 	: "=&r" (prev), "+m" (*(volatile u_long *)p)
726 	: "r" (p), "r" (v)
727 	: "cr0", "memory");
728 
729 	return (prev);
730 }
731 #endif
732 
733 #define	atomic_fetchadd_32	atomic_fetchadd_int
734 #define	atomic_swap_int		atomic_swap_32
735 
736 #ifdef __powerpc64__
737 #define	atomic_fetchadd_64	atomic_fetchadd_long
738 #define	atomic_swap_long	atomic_swap_64
739 #define	atomic_swap_ptr		atomic_swap_64
740 #endif
741 
742 #undef __ATOMIC_REL
743 #undef __ATOMIC_ACQ
744 
745 static __inline void
746 atomic_thread_fence_acq(void)
747 {
748 
749 	powerpc_lwsync();
750 }
751 
752 static __inline void
753 atomic_thread_fence_rel(void)
754 {
755 
756 	powerpc_lwsync();
757 }
758 
759 static __inline void
760 atomic_thread_fence_acq_rel(void)
761 {
762 
763 	powerpc_lwsync();
764 }
765 
766 static __inline void
767 atomic_thread_fence_seq_cst(void)
768 {
769 
770 	__asm __volatile("sync" : : : "memory");
771 }
772 
773 #endif /* ! _MACHINE_ATOMIC_H_ */
774