2 * Copyright (c) 1998 Doug Rabson
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 #ifndef _MACHINE_ATOMIC_H_
29 #define _MACHINE_ATOMIC_H_
32 #error this file needs sys/cdefs.h as a prerequisite
36 * Various simple arithmetic on memory which is atomic in the presence
37 * of interrupts and multiple processors.
39 * atomic_set_char(P, V) (*(u_char*)(P) |= (V))
40 * atomic_clear_char(P, V) (*(u_char*)(P) &= ~(V))
41 * atomic_add_char(P, V) (*(u_char*)(P) += (V))
42 * atomic_subtract_char(P, V) (*(u_char*)(P) -= (V))
44 * atomic_set_short(P, V) (*(u_short*)(P) |= (V))
45 * atomic_clear_short(P, V) (*(u_short*)(P) &= ~(V))
46 * atomic_add_short(P, V) (*(u_short*)(P) += (V))
47 * atomic_subtract_short(P, V) (*(u_short*)(P) -= (V))
49 * atomic_set_int(P, V) (*(u_int*)(P) |= (V))
50 * atomic_clear_int(P, V) (*(u_int*)(P) &= ~(V))
51 * atomic_add_int(P, V) (*(u_int*)(P) += (V))
52 * atomic_subtract_int(P, V) (*(u_int*)(P) -= (V))
53 * atomic_readandclear_int(P) (return *(u_int*)P; *(u_int*)P = 0;)
55 * atomic_set_long(P, V) (*(u_long*)(P) |= (V))
56 * atomic_clear_long(P, V) (*(u_long*)(P) &= ~(V))
57 * atomic_add_long(P, V) (*(u_long*)(P) += (V))
58 * atomic_subtract_long(P, V) (*(u_long*)(P) -= (V))
59 * atomic_readandclear_long(P) (return *(u_long*)P; *(u_long*)P = 0;)
63 * The above functions are expanded inline in the statically-linked
64 * kernel. Lock prefixes are generated if an SMP kernel is being
67 * Kernel modules call real functions which are built into the kernel.
68 * This allows kernel modules to be portable between UP and SMP systems.
70 #if defined(KLD_MODULE)
71 #define ATOMIC_ASM(NAME, TYPE, OP, CONS, V) \
72 void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
74 int atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src);
75 int atomic_cmpset_long(volatile u_long *dst, u_long exp, u_long src);
77 #define ATOMIC_STORE_LOAD(TYPE, LOP, SOP) \
78 u_##TYPE atomic_load_acq_##TYPE(volatile u_##TYPE *p); \
79 void atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
81 #else /* !KLD_MODULE */
83 #if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
86 * For userland, assume the SMP case and use lock prefixes so that
87 * the binaries will run on both types of systems.
89 #if defined(SMP) || !defined(_KERNEL)
90 #define MPLOCKED lock ;
96 * The assembly is volatilized to demark potential before-and-after side
97 * effects if an interrupt or SMP collision were to occur.
99 #define ATOMIC_ASM(NAME, TYPE, OP, CONS, V) \
100 static __inline void \
101 atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
103 __asm __volatile(__XSTRING(MPLOCKED) OP \
109 #else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
111 #define ATOMIC_ASM(NAME, TYPE, OP, CONS, V) \
112 extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
114 #endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
117 * Atomic compare and set, used by the mutex functions
119 * if (*dst == exp) *dst = src (all 32 bit words)
121 * Returns 0 on failure, non-zero on success
124 #if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
127 atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
132 " " __XSTRING(MPLOCKED) " "
137 "# atomic_cmpset_int"
138 : "+a" (res) /* 0 (result) */
147 atomic_cmpset_long(volatile u_long *dst, u_long exp, u_long src)
152 " " __XSTRING(MPLOCKED) " "
157 "# atomic_cmpset_long"
158 : "+a" (res) /* 0 (result) */
165 #endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
167 #if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
169 #define ATOMIC_STORE_LOAD(TYPE, LOP, SOP) \
170 static __inline u_##TYPE \
171 atomic_load_acq_##TYPE(volatile u_##TYPE *p) \
175 __asm __volatile(__XSTRING(MPLOCKED) LOP \
176 : "=a" (res), /* 0 (result) */\
184 * The XCHG instruction asserts LOCK automagically. \
186 static __inline void \
187 atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
189 __asm __volatile(SOP \
190 : "+m" (*p), /* 0 */ \
196 #else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
198 extern int atomic_cmpset_int(volatile u_int *, u_int, u_int);
199 extern int atomic_cmpset_long(volatile u_long *, u_long, u_long);
201 #define ATOMIC_STORE_LOAD(TYPE, LOP, SOP) \
202 extern u_##TYPE atomic_load_acq_##TYPE(volatile u_##TYPE *p); \
203 extern void atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
205 #endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
207 #endif /* KLD_MODULE */
209 ATOMIC_ASM(set, char, "orb %b1,%0", "iq", v);
210 ATOMIC_ASM(clear, char, "andb %b1,%0", "iq", ~v);
211 ATOMIC_ASM(add, char, "addb %b1,%0", "iq", v);
212 ATOMIC_ASM(subtract, char, "subb %b1,%0", "iq", v);
214 ATOMIC_ASM(set, short, "orw %w1,%0", "ir", v);
215 ATOMIC_ASM(clear, short, "andw %w1,%0", "ir", ~v);
216 ATOMIC_ASM(add, short, "addw %w1,%0", "ir", v);
217 ATOMIC_ASM(subtract, short, "subw %w1,%0", "ir", v);
219 ATOMIC_ASM(set, int, "orl %1,%0", "ir", v);
220 ATOMIC_ASM(clear, int, "andl %1,%0", "ir", ~v);
221 ATOMIC_ASM(add, int, "addl %1,%0", "ir", v);
222 ATOMIC_ASM(subtract, int, "subl %1,%0", "ir", v);
224 ATOMIC_ASM(set, long, "orq %1,%0", "ir", v);
225 ATOMIC_ASM(clear, long, "andq %1,%0", "ir", ~v);
226 ATOMIC_ASM(add, long, "addq %1,%0", "ir", v);
227 ATOMIC_ASM(subtract, long, "subq %1,%0", "ir", v);
229 ATOMIC_STORE_LOAD(char, "cmpxchgb %b0,%1", "xchgb %b1,%0");
230 ATOMIC_STORE_LOAD(short,"cmpxchgw %w0,%1", "xchgw %w1,%0");
231 ATOMIC_STORE_LOAD(int, "cmpxchgl %0,%1", "xchgl %1,%0");
232 ATOMIC_STORE_LOAD(long, "cmpxchgq %0,%1", "xchgq %1,%0");
235 #undef ATOMIC_STORE_LOAD
237 #define atomic_set_acq_char atomic_set_char
238 #define atomic_set_rel_char atomic_set_char
239 #define atomic_clear_acq_char atomic_clear_char
240 #define atomic_clear_rel_char atomic_clear_char
241 #define atomic_add_acq_char atomic_add_char
242 #define atomic_add_rel_char atomic_add_char
243 #define atomic_subtract_acq_char atomic_subtract_char
244 #define atomic_subtract_rel_char atomic_subtract_char
246 #define atomic_set_acq_short atomic_set_short
247 #define atomic_set_rel_short atomic_set_short
248 #define atomic_clear_acq_short atomic_clear_short
249 #define atomic_clear_rel_short atomic_clear_short
250 #define atomic_add_acq_short atomic_add_short
251 #define atomic_add_rel_short atomic_add_short
252 #define atomic_subtract_acq_short atomic_subtract_short
253 #define atomic_subtract_rel_short atomic_subtract_short
255 #define atomic_set_acq_int atomic_set_int
256 #define atomic_set_rel_int atomic_set_int
257 #define atomic_clear_acq_int atomic_clear_int
258 #define atomic_clear_rel_int atomic_clear_int
259 #define atomic_add_acq_int atomic_add_int
260 #define atomic_add_rel_int atomic_add_int
261 #define atomic_subtract_acq_int atomic_subtract_int
262 #define atomic_subtract_rel_int atomic_subtract_int
263 #define atomic_cmpset_acq_int atomic_cmpset_int
264 #define atomic_cmpset_rel_int atomic_cmpset_int
266 #define atomic_set_acq_long atomic_set_long
267 #define atomic_set_rel_long atomic_set_long
268 #define atomic_clear_acq_long atomic_clear_long
269 #define atomic_clear_rel_long atomic_clear_long
270 #define atomic_add_acq_long atomic_add_long
271 #define atomic_add_rel_long atomic_add_long
272 #define atomic_subtract_acq_long atomic_subtract_long
273 #define atomic_subtract_rel_long atomic_subtract_long
275 #define atomic_cmpset_acq_ptr atomic_cmpset_ptr
276 #define atomic_cmpset_rel_ptr atomic_cmpset_ptr
278 #define atomic_set_8 atomic_set_char
279 #define atomic_set_acq_8 atomic_set_acq_char
280 #define atomic_set_rel_8 atomic_set_rel_char
281 #define atomic_clear_8 atomic_clear_char
282 #define atomic_clear_acq_8 atomic_clear_acq_char
283 #define atomic_clear_rel_8 atomic_clear_rel_char
284 #define atomic_add_8 atomic_add_char
285 #define atomic_add_acq_8 atomic_add_acq_char
286 #define atomic_add_rel_8 atomic_add_rel_char
287 #define atomic_subtract_8 atomic_subtract_char
288 #define atomic_subtract_acq_8 atomic_subtract_acq_char
289 #define atomic_subtract_rel_8 atomic_subtract_rel_char
290 #define atomic_load_acq_8 atomic_load_acq_char
291 #define atomic_store_rel_8 atomic_store_rel_char
293 #define atomic_set_16 atomic_set_short
294 #define atomic_set_acq_16 atomic_set_acq_short
295 #define atomic_set_rel_16 atomic_set_rel_short
296 #define atomic_clear_16 atomic_clear_short
297 #define atomic_clear_acq_16 atomic_clear_acq_short
298 #define atomic_clear_rel_16 atomic_clear_rel_short
299 #define atomic_add_16 atomic_add_short
300 #define atomic_add_acq_16 atomic_add_acq_short
301 #define atomic_add_rel_16 atomic_add_rel_short
302 #define atomic_subtract_16 atomic_subtract_short
303 #define atomic_subtract_acq_16 atomic_subtract_acq_short
304 #define atomic_subtract_rel_16 atomic_subtract_rel_short
305 #define atomic_load_acq_16 atomic_load_acq_short
306 #define atomic_store_rel_16 atomic_store_rel_short
308 #define atomic_set_32 atomic_set_int
309 #define atomic_set_acq_32 atomic_set_acq_int
310 #define atomic_set_rel_32 atomic_set_rel_int
311 #define atomic_clear_32 atomic_clear_int
312 #define atomic_clear_acq_32 atomic_clear_acq_int
313 #define atomic_clear_rel_32 atomic_clear_rel_int
314 #define atomic_add_32 atomic_add_int
315 #define atomic_add_acq_32 atomic_add_acq_int
316 #define atomic_add_rel_32 atomic_add_rel_int
317 #define atomic_subtract_32 atomic_subtract_int
318 #define atomic_subtract_acq_32 atomic_subtract_acq_int
319 #define atomic_subtract_rel_32 atomic_subtract_rel_int
320 #define atomic_load_acq_32 atomic_load_acq_int
321 #define atomic_store_rel_32 atomic_store_rel_int
322 #define atomic_cmpset_32 atomic_cmpset_int
323 #define atomic_cmpset_acq_32 atomic_cmpset_acq_int
324 #define atomic_cmpset_rel_32 atomic_cmpset_rel_int
325 #define atomic_readandclear_32 atomic_readandclear_int
327 #if !defined(WANT_FUNCTIONS)
329 atomic_cmpset_ptr(volatile void *dst, void *exp, void *src)
332 return (atomic_cmpset_long((volatile u_long *)dst,
333 (u_long)exp, (u_long)src));
336 static __inline void *
337 atomic_load_acq_ptr(volatile void *p)
340 * The apparently-bogus cast to intptr_t in the following is to
341 * avoid a warning from "gcc -Wbad-function-cast".
343 return ((void *)(intptr_t)atomic_load_acq_long((volatile u_long *)p));
347 atomic_store_rel_ptr(volatile void *p, void *v)
349 atomic_store_rel_long((volatile u_long *)p, (u_long)v);
352 #define ATOMIC_PTR(NAME) \
353 static __inline void \
354 atomic_##NAME##_ptr(volatile void *p, uintptr_t v) \
356 atomic_##NAME##_long((volatile u_long *)p, v); \
359 static __inline void \
360 atomic_##NAME##_acq_ptr(volatile void *p, uintptr_t v) \
362 atomic_##NAME##_acq_long((volatile u_long *)p, v);\
365 static __inline void \
366 atomic_##NAME##_rel_ptr(volatile void *p, uintptr_t v) \
368 atomic_##NAME##_rel_long((volatile u_long *)p, v);\
378 #if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
380 static __inline u_int
381 atomic_readandclear_int(volatile u_int *addr)
388 "# atomic_readandclear_int"
389 : "=&r" (result) /* 0 (result) */
390 : "m" (*addr)); /* 1 (addr) */
395 static __inline u_long
396 atomic_readandclear_long(volatile u_long *addr)
403 "# atomic_readandclear_int"
404 : "=&r" (result) /* 0 (result) */
405 : "m" (*addr)); /* 1 (addr) */
410 #else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
412 extern u_long atomic_readandclear_long(volatile u_long *);
413 extern u_int atomic_readandclear_int(volatile u_int *);
415 #endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
417 #endif /* !defined(WANT_FUNCTIONS) */
418 #endif /* ! _MACHINE_ATOMIC_H_ */