xref: /freebsd/sys/i386/include/atomic.h (revision 15fe2513996eaa8857fcf66a632814b5f9374b03)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1998 Doug Rabson
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 #ifndef _MACHINE_ATOMIC_H_
31 #define	_MACHINE_ATOMIC_H_
32 
33 #ifndef _SYS_CDEFS_H_
34 #error this file needs sys/cdefs.h as a prerequisite
35 #endif
36 
37 #include <sys/atomic_common.h>
38 
39 #ifdef _KERNEL
40 #include <machine/md_var.h>
41 #include <machine/specialreg.h>
42 #endif
43 
44 #ifndef __OFFSETOF_MONITORBUF
45 /*
46  * __OFFSETOF_MONITORBUF == __pcpu_offset(pc_monitorbuf).
47  *
48  * The open-coded number is used instead of the symbolic expression to
49  * avoid a dependency on sys/pcpu.h in machine/atomic.h consumers.
50  * An assertion in i386/vm_machdep.c ensures that the value is correct.
51  */
52 #define	__OFFSETOF_MONITORBUF	0x80
53 
54 static __inline void
55 __mbk(void)
56 {
57 
58 	__asm __volatile("lock; addl $0,%%fs:%0"
59 	    : "+m" (*(u_int *)__OFFSETOF_MONITORBUF) : : "memory", "cc");
60 }
61 
62 static __inline void
63 __mbu(void)
64 {
65 
66 	__asm __volatile("lock; addl $0,(%%esp)" : : : "memory", "cc");
67 }
68 #endif
69 
70 /*
71  * Various simple operations on memory, each of which is atomic in the
72  * presence of interrupts and multiple processors.
73  *
74  * atomic_set_char(P, V)	(*(u_char *)(P) |= (V))
75  * atomic_clear_char(P, V)	(*(u_char *)(P) &= ~(V))
76  * atomic_add_char(P, V)	(*(u_char *)(P) += (V))
77  * atomic_subtract_char(P, V)	(*(u_char *)(P) -= (V))
78  *
79  * atomic_set_short(P, V)	(*(u_short *)(P) |= (V))
80  * atomic_clear_short(P, V)	(*(u_short *)(P) &= ~(V))
81  * atomic_add_short(P, V)	(*(u_short *)(P) += (V))
82  * atomic_subtract_short(P, V)	(*(u_short *)(P) -= (V))
83  *
84  * atomic_set_int(P, V)		(*(u_int *)(P) |= (V))
85  * atomic_clear_int(P, V)	(*(u_int *)(P) &= ~(V))
86  * atomic_add_int(P, V)		(*(u_int *)(P) += (V))
87  * atomic_subtract_int(P, V)	(*(u_int *)(P) -= (V))
88  * atomic_swap_int(P, V)	(return (*(u_int *)(P)); *(u_int *)(P) = (V);)
89  * atomic_readandclear_int(P)	(return (*(u_int *)(P)); *(u_int *)(P) = 0;)
90  *
91  * atomic_set_long(P, V)	(*(u_long *)(P) |= (V))
92  * atomic_clear_long(P, V)	(*(u_long *)(P) &= ~(V))
93  * atomic_add_long(P, V)	(*(u_long *)(P) += (V))
94  * atomic_subtract_long(P, V)	(*(u_long *)(P) -= (V))
95  * atomic_swap_long(P, V)	(return (*(u_long *)(P)); *(u_long *)(P) = (V);)
96  * atomic_readandclear_long(P)	(return (*(u_long *)(P)); *(u_long *)(P) = 0;)
97  */
98 
99 /*
100  * The above functions are expanded inline in the statically-linked
101  * kernel.  Lock prefixes are generated if an SMP kernel is being
102  * built.
103  *
104  * Kernel modules call real functions which are built into the kernel.
105  * This allows kernel modules to be portable between UP and SMP systems.
106  */
107 #if !defined(__GNUCLIKE_ASM)
108 #define	ATOMIC_ASM(NAME, TYPE, OP, CONS, V)			\
109 void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v);	\
110 void atomic_##NAME##_barr_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
111 
112 int	atomic_cmpset_char(volatile u_char *dst, u_char expect, u_char src);
113 int	atomic_cmpset_short(volatile u_short *dst, u_short expect, u_short src);
114 int	atomic_cmpset_int(volatile u_int *dst, u_int expect, u_int src);
115 int	atomic_fcmpset_char(volatile u_char *dst, u_char *expect, u_char src);
116 int	atomic_fcmpset_short(volatile u_short *dst, u_short *expect,
117 	    u_short src);
118 int	atomic_fcmpset_int(volatile u_int *dst, u_int *expect, u_int src);
119 u_int	atomic_fetchadd_int(volatile u_int *p, u_int v);
120 int	atomic_testandset_int(volatile u_int *p, u_int v);
121 int	atomic_testandclear_int(volatile u_int *p, u_int v);
122 void	atomic_thread_fence_acq(void);
123 void	atomic_thread_fence_acq_rel(void);
124 void	atomic_thread_fence_rel(void);
125 void	atomic_thread_fence_seq_cst(void);
126 
127 #define	ATOMIC_LOAD(TYPE)					\
128 u_##TYPE	atomic_load_acq_##TYPE(volatile u_##TYPE *p)
129 #define	ATOMIC_STORE(TYPE)					\
130 void		atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
131 
132 int		atomic_cmpset_64(volatile uint64_t *, uint64_t, uint64_t);
133 int		atomic_fcmpset_64(volatile uint64_t *, uint64_t *, uint64_t);
134 uint64_t	atomic_load_acq_64(volatile uint64_t *);
135 void		atomic_store_rel_64(volatile uint64_t *, uint64_t);
136 uint64_t	atomic_swap_64(volatile uint64_t *, uint64_t);
137 uint64_t	atomic_fetchadd_64(volatile uint64_t *, uint64_t);
138 void		atomic_add_64(volatile uint64_t *, uint64_t);
139 void		atomic_subtract_64(volatile uint64_t *, uint64_t);
140 
141 #else /* !KLD_MODULE && __GNUCLIKE_ASM */
142 
143 /*
144  * For userland, always use lock prefixes so that the binaries will run
145  * on both SMP and !SMP systems.
146  */
147 #if defined(SMP) || !defined(_KERNEL) || defined(KLD_MODULE)
148 #define	MPLOCKED	"lock ; "
149 #else
150 #define	MPLOCKED
151 #endif
152 
153 /*
154  * The assembly is volatilized to avoid code chunk removal by the compiler.
155  * GCC aggressively reorders operations and memory clobbering is necessary
156  * in order to avoid that for memory barriers.
157  */
158 #define	ATOMIC_ASM(NAME, TYPE, OP, CONS, V)		\
159 static __inline void					\
160 atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
161 {							\
162 	__asm __volatile(MPLOCKED OP			\
163 	: "+m" (*p)					\
164 	: CONS (V)					\
165 	: "cc");					\
166 }							\
167 							\
168 static __inline void					\
169 atomic_##NAME##_barr_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
170 {							\
171 	__asm __volatile(MPLOCKED OP			\
172 	: "+m" (*p)					\
173 	: CONS (V)					\
174 	: "memory", "cc");				\
175 }							\
176 struct __hack
177 
178 /*
179  * Atomic compare and set, used by the mutex functions.
180  *
181  * cmpset:
182  *	if (*dst == expect)
183  *		*dst = src
184  *
185  * fcmpset:
186  *	if (*dst == *expect)
187  *		*dst = src
188  *	else
189  *		*expect = *dst
190  *
191  * Returns 0 on failure, non-zero on success.
192  */
193 #define	ATOMIC_CMPSET(TYPE, CONS)			\
194 static __inline int					\
195 atomic_cmpset_##TYPE(volatile u_##TYPE *dst, u_##TYPE expect, u_##TYPE src) \
196 {							\
197 	u_char res;					\
198 							\
199 	__asm __volatile(				\
200 	"	" MPLOCKED "		"		\
201 	"	cmpxchg	%3,%1 ;		"		\
202 	"	sete	%0 ;		"		\
203 	"# atomic_cmpset_" #TYPE "	"		\
204 	: "=q" (res),			/* 0 */		\
205 	  "+m" (*dst),			/* 1 */		\
206 	  "+a" (expect)			/* 2 */		\
207 	: CONS (src)			/* 3 */		\
208 	: "memory", "cc");				\
209 	return (res);					\
210 }							\
211 							\
212 static __inline int					\
213 atomic_fcmpset_##TYPE(volatile u_##TYPE *dst, u_##TYPE *expect, u_##TYPE src) \
214 {							\
215 	u_char res;					\
216 							\
217 	__asm __volatile(				\
218 	"	" MPLOCKED "		"		\
219 	"	cmpxchg	%3,%1 ;		"		\
220 	"	sete	%0 ;		"		\
221 	"# atomic_fcmpset_" #TYPE "	"		\
222 	: "=q" (res),			/* 0 */		\
223 	  "+m" (*dst),			/* 1 */		\
224 	  "+a" (*expect)		/* 2 */		\
225 	: CONS (src)			/* 3 */		\
226 	: "memory", "cc");				\
227 	return (res);					\
228 }
229 
230 ATOMIC_CMPSET(char, "q");
231 ATOMIC_CMPSET(short, "r");
232 ATOMIC_CMPSET(int, "r");
233 
234 /*
235  * Atomically add the value of v to the integer pointed to by p and return
236  * the previous value of *p.
237  */
238 static __inline u_int
239 atomic_fetchadd_int(volatile u_int *p, u_int v)
240 {
241 
242 	__asm __volatile(
243 	"	" MPLOCKED "		"
244 	"	xaddl	%0,%1 ;		"
245 	"# atomic_fetchadd_int"
246 	: "+r" (v),			/* 0 */
247 	  "+m" (*p)			/* 1 */
248 	: : "cc");
249 	return (v);
250 }
251 
252 static __inline int
253 atomic_testandset_int(volatile u_int *p, u_int v)
254 {
255 	u_char res;
256 
257 	__asm __volatile(
258 	"	" MPLOCKED "		"
259 	"	btsl	%2,%1 ;		"
260 	"	setc	%0 ;		"
261 	"# atomic_testandset_int"
262 	: "=q" (res),			/* 0 */
263 	  "+m" (*p)			/* 1 */
264 	: "Ir" (v & 0x1f)		/* 2 */
265 	: "cc");
266 	return (res);
267 }
268 
269 static __inline int
270 atomic_testandclear_int(volatile u_int *p, u_int v)
271 {
272 	u_char res;
273 
274 	__asm __volatile(
275 	"	" MPLOCKED "		"
276 	"	btrl	%2,%1 ;		"
277 	"	setc	%0 ;		"
278 	"# atomic_testandclear_int"
279 	: "=q" (res),			/* 0 */
280 	  "+m" (*p)			/* 1 */
281 	: "Ir" (v & 0x1f)		/* 2 */
282 	: "cc");
283 	return (res);
284 }
285 
286 /*
287  * We assume that a = b will do atomic loads and stores.  Due to the
288  * IA32 memory model, a simple store guarantees release semantics.
289  *
290  * However, a load may pass a store if they are performed on distinct
291  * addresses, so we need Store/Load barrier for sequentially
292  * consistent fences in SMP kernels.  We use "lock addl $0,mem" for a
293  * Store/Load barrier, as recommended by the AMD Software Optimization
294  * Guide, and not mfence.  In the kernel, we use a private per-cpu
295  * cache line for "mem", to avoid introducing false data
296  * dependencies.  In user space, we use the word at the top of the
297  * stack.
298  *
299  * For UP kernels, however, the memory of the single processor is
300  * always consistent, so we only need to stop the compiler from
301  * reordering accesses in a way that violates the semantics of acquire
302  * and release.
303  */
304 
305 #if defined(_KERNEL)
306 #if defined(SMP) || defined(KLD_MODULE)
307 #define	__storeload_barrier()	__mbk()
308 #else /* _KERNEL && UP */
309 #define	__storeload_barrier()	__compiler_membar()
310 #endif /* SMP */
311 #else /* !_KERNEL */
312 #define	__storeload_barrier()	__mbu()
313 #endif /* _KERNEL*/
314 
315 #define	ATOMIC_LOAD(TYPE)					\
316 static __inline u_##TYPE					\
317 atomic_load_acq_##TYPE(volatile u_##TYPE *p)			\
318 {								\
319 	u_##TYPE res;						\
320 								\
321 	res = *p;						\
322 	__compiler_membar();					\
323 	return (res);						\
324 }								\
325 struct __hack
326 
327 #define	ATOMIC_STORE(TYPE)					\
328 static __inline void						\
329 atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)	\
330 {								\
331 								\
332 	__compiler_membar();					\
333 	*p = v;							\
334 }								\
335 struct __hack
336 
337 static __inline void
338 atomic_thread_fence_acq(void)
339 {
340 
341 	__compiler_membar();
342 }
343 
344 static __inline void
345 atomic_thread_fence_rel(void)
346 {
347 
348 	__compiler_membar();
349 }
350 
351 static __inline void
352 atomic_thread_fence_acq_rel(void)
353 {
354 
355 	__compiler_membar();
356 }
357 
358 static __inline void
359 atomic_thread_fence_seq_cst(void)
360 {
361 
362 	__storeload_barrier();
363 }
364 
365 #ifdef _KERNEL
366 
367 #ifdef WANT_FUNCTIONS
368 int		atomic_cmpset_64_i386(volatile uint64_t *, uint64_t, uint64_t);
369 int		atomic_cmpset_64_i586(volatile uint64_t *, uint64_t, uint64_t);
370 uint64_t	atomic_load_acq_64_i386(volatile uint64_t *);
371 uint64_t	atomic_load_acq_64_i586(volatile uint64_t *);
372 void		atomic_store_rel_64_i386(volatile uint64_t *, uint64_t);
373 void		atomic_store_rel_64_i586(volatile uint64_t *, uint64_t);
374 uint64_t	atomic_swap_64_i386(volatile uint64_t *, uint64_t);
375 uint64_t	atomic_swap_64_i586(volatile uint64_t *, uint64_t);
376 #endif
377 
378 /* I486 does not support SMP or CMPXCHG8B. */
379 static __inline int
380 atomic_cmpset_64_i386(volatile uint64_t *dst, uint64_t expect, uint64_t src)
381 {
382 	volatile uint32_t *p;
383 	u_char res;
384 
385 	p = (volatile uint32_t *)dst;
386 	__asm __volatile(
387 	"	pushfl ;		"
388 	"	cli ;			"
389 	"	xorl	%1,%%eax ;	"
390 	"	xorl	%2,%%edx ;	"
391 	"	orl	%%edx,%%eax ;	"
392 	"	jne	1f ;		"
393 	"	movl	%4,%1 ;		"
394 	"	movl	%5,%2 ;		"
395 	"1:				"
396 	"	sete	%3 ;		"
397 	"	popfl"
398 	: "+A" (expect),		/* 0 */
399 	  "+m" (*p),			/* 1 */
400 	  "+m" (*(p + 1)),		/* 2 */
401 	  "=q" (res)			/* 3 */
402 	: "r" ((uint32_t)src),		/* 4 */
403 	  "r" ((uint32_t)(src >> 32))	/* 5 */
404 	: "memory", "cc");
405 	return (res);
406 }
407 
408 static __inline int
409 atomic_fcmpset_64_i386(volatile uint64_t *dst, uint64_t *expect, uint64_t src)
410 {
411 
412 	if (atomic_cmpset_64_i386(dst, *expect, src)) {
413 		return (1);
414 	} else {
415 		*expect = *dst;
416 		return (0);
417 	}
418 }
419 
420 static __inline uint64_t
421 atomic_load_acq_64_i386(volatile uint64_t *p)
422 {
423 	volatile uint32_t *q;
424 	uint64_t res;
425 
426 	q = (volatile uint32_t *)p;
427 	__asm __volatile(
428 	"	pushfl ;		"
429 	"	cli ;			"
430 	"	movl	%1,%%eax ;	"
431 	"	movl	%2,%%edx ;	"
432 	"	popfl"
433 	: "=&A" (res)			/* 0 */
434 	: "m" (*q),			/* 1 */
435 	  "m" (*(q + 1))		/* 2 */
436 	: "memory");
437 	return (res);
438 }
439 
440 static __inline void
441 atomic_store_rel_64_i386(volatile uint64_t *p, uint64_t v)
442 {
443 	volatile uint32_t *q;
444 
445 	q = (volatile uint32_t *)p;
446 	__asm __volatile(
447 	"	pushfl ;		"
448 	"	cli ;			"
449 	"	movl	%%eax,%0 ;	"
450 	"	movl	%%edx,%1 ;	"
451 	"	popfl"
452 	: "=m" (*q),			/* 0 */
453 	  "=m" (*(q + 1))		/* 1 */
454 	: "A" (v)			/* 2 */
455 	: "memory");
456 }
457 
458 static __inline uint64_t
459 atomic_swap_64_i386(volatile uint64_t *p, uint64_t v)
460 {
461 	volatile uint32_t *q;
462 	uint64_t res;
463 
464 	q = (volatile uint32_t *)p;
465 	__asm __volatile(
466 	"	pushfl ;		"
467 	"	cli ;			"
468 	"	movl	%1,%%eax ;	"
469 	"	movl	%2,%%edx ;	"
470 	"	movl	%4,%2 ;		"
471 	"	movl	%3,%1 ;		"
472 	"	popfl"
473 	: "=&A" (res),			/* 0 */
474 	  "+m" (*q),			/* 1 */
475 	  "+m" (*(q + 1))		/* 2 */
476 	: "r" ((uint32_t)v),		/* 3 */
477 	  "r" ((uint32_t)(v >> 32)));	/* 4 */
478 	return (res);
479 }
480 
481 static __inline int
482 atomic_cmpset_64_i586(volatile uint64_t *dst, uint64_t expect, uint64_t src)
483 {
484 	u_char res;
485 
486 	__asm __volatile(
487 	"	" MPLOCKED "		"
488 	"	cmpxchg8b %1 ;		"
489 	"	sete	%0"
490 	: "=q" (res),			/* 0 */
491 	  "+m" (*dst),			/* 1 */
492 	  "+A" (expect)			/* 2 */
493 	: "b" ((uint32_t)src),		/* 3 */
494 	  "c" ((uint32_t)(src >> 32))	/* 4 */
495 	: "memory", "cc");
496 	return (res);
497 }
498 
499 static __inline int
500 atomic_fcmpset_64_i586(volatile uint64_t *dst, uint64_t *expect, uint64_t src)
501 {
502 	u_char res;
503 
504 	__asm __volatile(
505 	"	" MPLOCKED "		"
506 	"	cmpxchg8b %1 ;		"
507 	"	sete	%0"
508 	: "=q" (res),			/* 0 */
509 	  "+m" (*dst),			/* 1 */
510 	  "+A" (*expect)		/* 2 */
511 	: "b" ((uint32_t)src),		/* 3 */
512 	  "c" ((uint32_t)(src >> 32))	/* 4 */
513 	: "memory", "cc");
514 	return (res);
515 }
516 
517 static __inline uint64_t
518 atomic_load_acq_64_i586(volatile uint64_t *p)
519 {
520 	uint64_t res;
521 
522 	__asm __volatile(
523 	"	movl	%%ebx,%%eax ;	"
524 	"	movl	%%ecx,%%edx ;	"
525 	"	" MPLOCKED "		"
526 	"	cmpxchg8b %1"
527 	: "=&A" (res),			/* 0 */
528 	  "+m" (*p)			/* 1 */
529 	: : "memory", "cc");
530 	return (res);
531 }
532 
533 static __inline void
534 atomic_store_rel_64_i586(volatile uint64_t *p, uint64_t v)
535 {
536 
537 	__asm __volatile(
538 	"	movl	%%eax,%%ebx ;	"
539 	"	movl	%%edx,%%ecx ;	"
540 	"1:				"
541 	"	" MPLOCKED "		"
542 	"	cmpxchg8b %0 ;		"
543 	"	jne	1b"
544 	: "+m" (*p),			/* 0 */
545 	  "+A" (v)			/* 1 */
546 	: : "ebx", "ecx", "memory", "cc");
547 }
548 
549 static __inline uint64_t
550 atomic_swap_64_i586(volatile uint64_t *p, uint64_t v)
551 {
552 
553 	__asm __volatile(
554 	"	movl	%%eax,%%ebx ;	"
555 	"	movl	%%edx,%%ecx ;	"
556 	"1:				"
557 	"	" MPLOCKED "		"
558 	"	cmpxchg8b %0 ;		"
559 	"	jne	1b"
560 	: "+m" (*p),			/* 0 */
561 	  "+A" (v)			/* 1 */
562 	: : "ebx", "ecx", "memory", "cc");
563 	return (v);
564 }
565 
566 static __inline int
567 atomic_cmpset_64(volatile uint64_t *dst, uint64_t expect, uint64_t src)
568 {
569 
570 	if ((cpu_feature & CPUID_CX8) == 0)
571 		return (atomic_cmpset_64_i386(dst, expect, src));
572 	else
573 		return (atomic_cmpset_64_i586(dst, expect, src));
574 }
575 
576 static __inline int
577 atomic_fcmpset_64(volatile uint64_t *dst, uint64_t *expect, uint64_t src)
578 {
579 
580   	if ((cpu_feature & CPUID_CX8) == 0)
581 		return (atomic_fcmpset_64_i386(dst, expect, src));
582 	else
583 		return (atomic_fcmpset_64_i586(dst, expect, src));
584 }
585 
586 static __inline uint64_t
587 atomic_load_acq_64(volatile uint64_t *p)
588 {
589 
590 	if ((cpu_feature & CPUID_CX8) == 0)
591 		return (atomic_load_acq_64_i386(p));
592 	else
593 		return (atomic_load_acq_64_i586(p));
594 }
595 
596 static __inline void
597 atomic_store_rel_64(volatile uint64_t *p, uint64_t v)
598 {
599 
600 	if ((cpu_feature & CPUID_CX8) == 0)
601 		atomic_store_rel_64_i386(p, v);
602 	else
603 		atomic_store_rel_64_i586(p, v);
604 }
605 
606 static __inline uint64_t
607 atomic_swap_64(volatile uint64_t *p, uint64_t v)
608 {
609 
610 	if ((cpu_feature & CPUID_CX8) == 0)
611 		return (atomic_swap_64_i386(p, v));
612 	else
613 		return (atomic_swap_64_i586(p, v));
614 }
615 
616 static __inline uint64_t
617 atomic_fetchadd_64(volatile uint64_t *p, uint64_t v)
618 {
619 
620 	for (;;) {
621 		uint64_t t = *p;
622 		if (atomic_cmpset_64(p, t, t + v))
623 			return (t);
624 	}
625 }
626 
627 static __inline void
628 atomic_add_64(volatile uint64_t *p, uint64_t v)
629 {
630 	uint64_t t;
631 
632 	for (;;) {
633 		t = *p;
634 		if (atomic_cmpset_64(p, t, t + v))
635 			break;
636 	}
637 }
638 
639 static __inline void
640 atomic_subtract_64(volatile uint64_t *p, uint64_t v)
641 {
642 	uint64_t t;
643 
644 	for (;;) {
645 		t = *p;
646 		if (atomic_cmpset_64(p, t, t - v))
647 			break;
648 	}
649 }
650 
651 #endif /* _KERNEL */
652 
653 #endif /* KLD_MODULE || !__GNUCLIKE_ASM */
654 
655 ATOMIC_ASM(set,	     char,  "orb %b1,%0",  "iq",  v);
656 ATOMIC_ASM(clear,    char,  "andb %b1,%0", "iq", ~v);
657 ATOMIC_ASM(add,	     char,  "addb %b1,%0", "iq",  v);
658 ATOMIC_ASM(subtract, char,  "subb %b1,%0", "iq",  v);
659 
660 ATOMIC_ASM(set,	     short, "orw %w1,%0",  "ir",  v);
661 ATOMIC_ASM(clear,    short, "andw %w1,%0", "ir", ~v);
662 ATOMIC_ASM(add,	     short, "addw %w1,%0", "ir",  v);
663 ATOMIC_ASM(subtract, short, "subw %w1,%0", "ir",  v);
664 
665 ATOMIC_ASM(set,	     int,   "orl %1,%0",   "ir",  v);
666 ATOMIC_ASM(clear,    int,   "andl %1,%0",  "ir", ~v);
667 ATOMIC_ASM(add,	     int,   "addl %1,%0",  "ir",  v);
668 ATOMIC_ASM(subtract, int,   "subl %1,%0",  "ir",  v);
669 
670 ATOMIC_ASM(set,	     long,  "orl %1,%0",   "ir",  v);
671 ATOMIC_ASM(clear,    long,  "andl %1,%0",  "ir", ~v);
672 ATOMIC_ASM(add,	     long,  "addl %1,%0",  "ir",  v);
673 ATOMIC_ASM(subtract, long,  "subl %1,%0",  "ir",  v);
674 
675 #define	ATOMIC_LOADSTORE(TYPE)				\
676 	ATOMIC_LOAD(TYPE);				\
677 	ATOMIC_STORE(TYPE)
678 
679 ATOMIC_LOADSTORE(char);
680 ATOMIC_LOADSTORE(short);
681 ATOMIC_LOADSTORE(int);
682 ATOMIC_LOADSTORE(long);
683 
684 #undef ATOMIC_ASM
685 #undef ATOMIC_LOAD
686 #undef ATOMIC_STORE
687 #undef ATOMIC_LOADSTORE
688 
689 #ifndef WANT_FUNCTIONS
690 
691 static __inline int
692 atomic_cmpset_long(volatile u_long *dst, u_long expect, u_long src)
693 {
694 
695 	return (atomic_cmpset_int((volatile u_int *)dst, (u_int)expect,
696 	    (u_int)src));
697 }
698 
699 static __inline int
700 atomic_fcmpset_long(volatile u_long *dst, u_long *expect, u_long src)
701 {
702 
703 	return (atomic_fcmpset_int((volatile u_int *)dst, (u_int *)expect,
704 	    (u_int)src));
705 }
706 
707 static __inline u_long
708 atomic_fetchadd_long(volatile u_long *p, u_long v)
709 {
710 
711 	return (atomic_fetchadd_int((volatile u_int *)p, (u_int)v));
712 }
713 
714 static __inline int
715 atomic_testandset_long(volatile u_long *p, u_int v)
716 {
717 
718 	return (atomic_testandset_int((volatile u_int *)p, v));
719 }
720 
721 static __inline int
722 atomic_testandclear_long(volatile u_long *p, u_int v)
723 {
724 
725 	return (atomic_testandclear_int((volatile u_int *)p, v));
726 }
727 
728 /* Read the current value and store a new value in the destination. */
729 #ifdef __GNUCLIKE_ASM
730 
731 static __inline u_int
732 atomic_swap_int(volatile u_int *p, u_int v)
733 {
734 
735 	__asm __volatile(
736 	"	xchgl	%1,%0 ;		"
737 	"# atomic_swap_int"
738 	: "+r" (v),			/* 0 */
739 	  "+m" (*p));			/* 1 */
740 	return (v);
741 }
742 
743 static __inline u_long
744 atomic_swap_long(volatile u_long *p, u_long v)
745 {
746 
747 	return (atomic_swap_int((volatile u_int *)p, (u_int)v));
748 }
749 
750 #else /* !__GNUCLIKE_ASM */
751 
752 u_int	atomic_swap_int(volatile u_int *p, u_int v);
753 u_long	atomic_swap_long(volatile u_long *p, u_long v);
754 
755 #endif /* __GNUCLIKE_ASM */
756 
757 #define	atomic_set_acq_char		atomic_set_barr_char
758 #define	atomic_set_rel_char		atomic_set_barr_char
759 #define	atomic_clear_acq_char		atomic_clear_barr_char
760 #define	atomic_clear_rel_char		atomic_clear_barr_char
761 #define	atomic_add_acq_char		atomic_add_barr_char
762 #define	atomic_add_rel_char		atomic_add_barr_char
763 #define	atomic_subtract_acq_char	atomic_subtract_barr_char
764 #define	atomic_subtract_rel_char	atomic_subtract_barr_char
765 #define	atomic_cmpset_acq_char		atomic_cmpset_char
766 #define	atomic_cmpset_rel_char		atomic_cmpset_char
767 #define	atomic_fcmpset_acq_char		atomic_fcmpset_char
768 #define	atomic_fcmpset_rel_char		atomic_fcmpset_char
769 
770 #define	atomic_set_acq_short		atomic_set_barr_short
771 #define	atomic_set_rel_short		atomic_set_barr_short
772 #define	atomic_clear_acq_short		atomic_clear_barr_short
773 #define	atomic_clear_rel_short		atomic_clear_barr_short
774 #define	atomic_add_acq_short		atomic_add_barr_short
775 #define	atomic_add_rel_short		atomic_add_barr_short
776 #define	atomic_subtract_acq_short	atomic_subtract_barr_short
777 #define	atomic_subtract_rel_short	atomic_subtract_barr_short
778 #define	atomic_cmpset_acq_short		atomic_cmpset_short
779 #define	atomic_cmpset_rel_short		atomic_cmpset_short
780 #define	atomic_fcmpset_acq_short	atomic_fcmpset_short
781 #define	atomic_fcmpset_rel_short	atomic_fcmpset_short
782 
783 #define	atomic_set_acq_int		atomic_set_barr_int
784 #define	atomic_set_rel_int		atomic_set_barr_int
785 #define	atomic_clear_acq_int		atomic_clear_barr_int
786 #define	atomic_clear_rel_int		atomic_clear_barr_int
787 #define	atomic_add_acq_int		atomic_add_barr_int
788 #define	atomic_add_rel_int		atomic_add_barr_int
789 #define	atomic_subtract_acq_int		atomic_subtract_barr_int
790 #define	atomic_subtract_rel_int		atomic_subtract_barr_int
791 #define	atomic_cmpset_acq_int		atomic_cmpset_int
792 #define	atomic_cmpset_rel_int		atomic_cmpset_int
793 #define	atomic_fcmpset_acq_int		atomic_fcmpset_int
794 #define	atomic_fcmpset_rel_int		atomic_fcmpset_int
795 
796 #define	atomic_set_acq_long		atomic_set_barr_long
797 #define	atomic_set_rel_long		atomic_set_barr_long
798 #define	atomic_clear_acq_long		atomic_clear_barr_long
799 #define	atomic_clear_rel_long		atomic_clear_barr_long
800 #define	atomic_add_acq_long		atomic_add_barr_long
801 #define	atomic_add_rel_long		atomic_add_barr_long
802 #define	atomic_subtract_acq_long	atomic_subtract_barr_long
803 #define	atomic_subtract_rel_long	atomic_subtract_barr_long
804 #define	atomic_cmpset_acq_long		atomic_cmpset_long
805 #define	atomic_cmpset_rel_long		atomic_cmpset_long
806 #define	atomic_fcmpset_acq_long		atomic_fcmpset_long
807 #define	atomic_fcmpset_rel_long		atomic_fcmpset_long
808 
809 #define	atomic_readandclear_int(p)	atomic_swap_int(p, 0)
810 #define	atomic_readandclear_long(p)	atomic_swap_long(p, 0)
811 
812 /* Operations on 8-bit bytes. */
813 #define	atomic_set_8		atomic_set_char
814 #define	atomic_set_acq_8	atomic_set_acq_char
815 #define	atomic_set_rel_8	atomic_set_rel_char
816 #define	atomic_clear_8		atomic_clear_char
817 #define	atomic_clear_acq_8	atomic_clear_acq_char
818 #define	atomic_clear_rel_8	atomic_clear_rel_char
819 #define	atomic_add_8		atomic_add_char
820 #define	atomic_add_acq_8	atomic_add_acq_char
821 #define	atomic_add_rel_8	atomic_add_rel_char
822 #define	atomic_subtract_8	atomic_subtract_char
823 #define	atomic_subtract_acq_8	atomic_subtract_acq_char
824 #define	atomic_subtract_rel_8	atomic_subtract_rel_char
825 #define	atomic_load_acq_8	atomic_load_acq_char
826 #define	atomic_store_rel_8	atomic_store_rel_char
827 #define	atomic_cmpset_8		atomic_cmpset_char
828 #define	atomic_cmpset_acq_8	atomic_cmpset_acq_char
829 #define	atomic_cmpset_rel_8	atomic_cmpset_rel_char
830 #define	atomic_fcmpset_8	atomic_fcmpset_char
831 #define	atomic_fcmpset_acq_8	atomic_fcmpset_acq_char
832 #define	atomic_fcmpset_rel_8	atomic_fcmpset_rel_char
833 
834 /* Operations on 16-bit words. */
835 #define	atomic_set_16		atomic_set_short
836 #define	atomic_set_acq_16	atomic_set_acq_short
837 #define	atomic_set_rel_16	atomic_set_rel_short
838 #define	atomic_clear_16		atomic_clear_short
839 #define	atomic_clear_acq_16	atomic_clear_acq_short
840 #define	atomic_clear_rel_16	atomic_clear_rel_short
841 #define	atomic_add_16		atomic_add_short
842 #define	atomic_add_acq_16	atomic_add_acq_short
843 #define	atomic_add_rel_16	atomic_add_rel_short
844 #define	atomic_subtract_16	atomic_subtract_short
845 #define	atomic_subtract_acq_16	atomic_subtract_acq_short
846 #define	atomic_subtract_rel_16	atomic_subtract_rel_short
847 #define	atomic_load_acq_16	atomic_load_acq_short
848 #define	atomic_store_rel_16	atomic_store_rel_short
849 #define	atomic_cmpset_16	atomic_cmpset_short
850 #define	atomic_cmpset_acq_16	atomic_cmpset_acq_short
851 #define	atomic_cmpset_rel_16	atomic_cmpset_rel_short
852 #define	atomic_fcmpset_16	atomic_fcmpset_short
853 #define	atomic_fcmpset_acq_16	atomic_fcmpset_acq_short
854 #define	atomic_fcmpset_rel_16	atomic_fcmpset_rel_short
855 
856 /* Operations on 32-bit double words. */
857 #define	atomic_set_32		atomic_set_int
858 #define	atomic_set_acq_32	atomic_set_acq_int
859 #define	atomic_set_rel_32	atomic_set_rel_int
860 #define	atomic_clear_32		atomic_clear_int
861 #define	atomic_clear_acq_32	atomic_clear_acq_int
862 #define	atomic_clear_rel_32	atomic_clear_rel_int
863 #define	atomic_add_32		atomic_add_int
864 #define	atomic_add_acq_32	atomic_add_acq_int
865 #define	atomic_add_rel_32	atomic_add_rel_int
866 #define	atomic_subtract_32	atomic_subtract_int
867 #define	atomic_subtract_acq_32	atomic_subtract_acq_int
868 #define	atomic_subtract_rel_32	atomic_subtract_rel_int
869 #define	atomic_load_acq_32	atomic_load_acq_int
870 #define	atomic_store_rel_32	atomic_store_rel_int
871 #define	atomic_cmpset_32	atomic_cmpset_int
872 #define	atomic_cmpset_acq_32	atomic_cmpset_acq_int
873 #define	atomic_cmpset_rel_32	atomic_cmpset_rel_int
874 #define	atomic_fcmpset_32	atomic_fcmpset_int
875 #define	atomic_fcmpset_acq_32	atomic_fcmpset_acq_int
876 #define	atomic_fcmpset_rel_32	atomic_fcmpset_rel_int
877 #define	atomic_swap_32		atomic_swap_int
878 #define	atomic_readandclear_32	atomic_readandclear_int
879 #define	atomic_fetchadd_32	atomic_fetchadd_int
880 #define	atomic_testandset_32	atomic_testandset_int
881 #define	atomic_testandclear_32	atomic_testandclear_int
882 
883 #ifdef _KERNEL
884 /* Operations on 64-bit quad words. */
885 #define	atomic_cmpset_acq_64 atomic_cmpset_64
886 #define	atomic_cmpset_rel_64 atomic_cmpset_64
887 #define	atomic_fcmpset_acq_64 atomic_fcmpset_64
888 #define	atomic_fcmpset_rel_64 atomic_fcmpset_64
889 #define	atomic_fetchadd_acq_64	atomic_fetchadd_64
890 #define	atomic_fetchadd_rel_64	atomic_fetchadd_64
891 #define	atomic_add_acq_64 atomic_add_64
892 #define	atomic_add_rel_64 atomic_add_64
893 #define	atomic_subtract_acq_64 atomic_subtract_64
894 #define	atomic_subtract_rel_64 atomic_subtract_64
895 #define	atomic_load_64 atomic_load_acq_64
896 #define	atomic_store_64 atomic_store_rel_64
897 #endif
898 
899 /* Operations on pointers. */
900 #define	atomic_set_ptr(p, v) \
901 	atomic_set_int((volatile u_int *)(p), (u_int)(v))
902 #define	atomic_set_acq_ptr(p, v) \
903 	atomic_set_acq_int((volatile u_int *)(p), (u_int)(v))
904 #define	atomic_set_rel_ptr(p, v) \
905 	atomic_set_rel_int((volatile u_int *)(p), (u_int)(v))
906 #define	atomic_clear_ptr(p, v) \
907 	atomic_clear_int((volatile u_int *)(p), (u_int)(v))
908 #define	atomic_clear_acq_ptr(p, v) \
909 	atomic_clear_acq_int((volatile u_int *)(p), (u_int)(v))
910 #define	atomic_clear_rel_ptr(p, v) \
911 	atomic_clear_rel_int((volatile u_int *)(p), (u_int)(v))
912 #define	atomic_add_ptr(p, v) \
913 	atomic_add_int((volatile u_int *)(p), (u_int)(v))
914 #define	atomic_add_acq_ptr(p, v) \
915 	atomic_add_acq_int((volatile u_int *)(p), (u_int)(v))
916 #define	atomic_add_rel_ptr(p, v) \
917 	atomic_add_rel_int((volatile u_int *)(p), (u_int)(v))
918 #define	atomic_subtract_ptr(p, v) \
919 	atomic_subtract_int((volatile u_int *)(p), (u_int)(v))
920 #define	atomic_subtract_acq_ptr(p, v) \
921 	atomic_subtract_acq_int((volatile u_int *)(p), (u_int)(v))
922 #define	atomic_subtract_rel_ptr(p, v) \
923 	atomic_subtract_rel_int((volatile u_int *)(p), (u_int)(v))
924 #define	atomic_load_acq_ptr(p) \
925 	atomic_load_acq_int((volatile u_int *)(p))
926 #define	atomic_store_rel_ptr(p, v) \
927 	atomic_store_rel_int((volatile u_int *)(p), (v))
928 #define	atomic_cmpset_ptr(dst, old, new) \
929 	atomic_cmpset_int((volatile u_int *)(dst), (u_int)(old), (u_int)(new))
930 #define	atomic_cmpset_acq_ptr(dst, old, new) \
931 	atomic_cmpset_acq_int((volatile u_int *)(dst), (u_int)(old), \
932 	    (u_int)(new))
933 #define	atomic_cmpset_rel_ptr(dst, old, new) \
934 	atomic_cmpset_rel_int((volatile u_int *)(dst), (u_int)(old), \
935 	    (u_int)(new))
936 #define	atomic_fcmpset_ptr(dst, old, new) \
937 	atomic_fcmpset_int((volatile u_int *)(dst), (u_int *)(old), (u_int)(new))
938 #define	atomic_fcmpset_acq_ptr(dst, old, new) \
939 	atomic_fcmpset_acq_int((volatile u_int *)(dst), (u_int *)(old), \
940 	    (u_int)(new))
941 #define	atomic_fcmpset_rel_ptr(dst, old, new) \
942 	atomic_fcmpset_rel_int((volatile u_int *)(dst), (u_int *)(old), \
943 	    (u_int)(new))
944 #define	atomic_swap_ptr(p, v) \
945 	atomic_swap_int((volatile u_int *)(p), (u_int)(v))
946 #define	atomic_readandclear_ptr(p) \
947 	atomic_readandclear_int((volatile u_int *)(p))
948 
949 #endif /* !WANT_FUNCTIONS */
950 
951 #if defined(_KERNEL)
952 #define	mb()	__mbk()
953 #define	wmb()	__mbk()
954 #define	rmb()	__mbk()
955 #else
956 #define	mb()	__mbu()
957 #define	wmb()	__mbu()
958 #define	rmb()	__mbu()
959 #endif
960 
961 #endif /* !_MACHINE_ATOMIC_H_ */
962