1 /*-
2 * Copyright (c) 1998 Doug Rabson
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
13 *
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
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: releng/5.3/sys/amd64/include/atomic.h 122940 2003-11-21 03:02:00Z peter $
27 */
28 #ifndef _MACHINE_ATOMIC_H_
29 #define _MACHINE_ATOMIC_H_
30
31 /*
32 * Various simple arithmetic on memory which is atomic in the presence
33 * of interrupts and multiple processors.
34 *
35 * atomic_set_char(P, V) (*(u_char*)(P) |= (V))
36 * atomic_clear_char(P, V) (*(u_char*)(P) &= ~(V))
37 * atomic_add_char(P, V) (*(u_char*)(P) += (V))
38 * atomic_subtract_char(P, V) (*(u_char*)(P) -= (V))
39 *
40 * atomic_set_short(P, V) (*(u_short*)(P) |= (V))
41 * atomic_clear_short(P, V) (*(u_short*)(P) &= ~(V))
42 * atomic_add_short(P, V) (*(u_short*)(P) += (V))
43 * atomic_subtract_short(P, V) (*(u_short*)(P) -= (V))
44 *
45 * atomic_set_int(P, V) (*(u_int*)(P) |= (V))
46 * atomic_clear_int(P, V) (*(u_int*)(P) &= ~(V))
47 * atomic_add_int(P, V) (*(u_int*)(P) += (V))
48 * atomic_subtract_int(P, V) (*(u_int*)(P) -= (V))
49 * atomic_readandclear_int(P) (return *(u_int*)P; *(u_int*)P = 0;)
50 *
51 * atomic_set_long(P, V) (*(u_long*)(P) |= (V))
52 * atomic_clear_long(P, V) (*(u_long*)(P) &= ~(V))
53 * atomic_add_long(P, V) (*(u_long*)(P) += (V))
54 * atomic_subtract_long(P, V) (*(u_long*)(P) -= (V))
55 * atomic_readandclear_long(P) (return *(u_long*)P; *(u_long*)P = 0;)
56 */
57
58 /*
59 * The above functions are expanded inline in the statically-linked
60 * kernel. Lock prefixes are generated if an SMP kernel is being
61 * built.
62 *
63 * Kernel modules call real functions which are built into the kernel.
64 * This allows kernel modules to be portable between UP and SMP systems.
65 */
66 #if defined(KLD_MODULE)
67 #define ATOMIC_ASM(NAME, TYPE, OP, CONS, V) \
68 void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
69
70 int atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src);
71 int atomic_cmpset_long(volatile u_long *dst, u_long exp, u_long src);
72
73 #define ATOMIC_STORE_LOAD(TYPE, LOP, SOP) \
74 u_##TYPE atomic_load_acq_##TYPE(volatile u_##TYPE *p); \
75 void atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
76
77 #else /* !KLD_MODULE */
78
79 #ifdef __GNUC__
80
81 /*
82 * For userland, assume the SMP case and use lock prefixes so that
83 * the binaries will run on both types of systems.
84 */
85 #if defined(SMP) || !defined(_KERNEL)
86 #define MPLOCKED lock ;
87 #else
88 #define MPLOCKED
89 #endif
90
91 /*
92 * The assembly is volatilized to demark potential before-and-after side
93 * effects if an interrupt or SMP collision were to occur.
94 */
95 #define ATOMIC_ASM(NAME, TYPE, OP, CONS, V) \
96 static __inline void \
97 atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
98 { \
99 __asm __volatile(__XSTRING(MPLOCKED) OP \
100 : "+m" (*p) \
101 : CONS (V)); \
102 } \
103 struct __hack
104
105 #else /* !__GNUC__ */
106
107 #define ATOMIC_ASM(NAME, TYPE, OP, CONS, V) \
108 extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
109
110 #endif /* __GNUC__ */
111
112 /*
113 * Atomic compare and set, used by the mutex functions
114 *
115 * if (*dst == exp) *dst = src (all 32 bit words)
116 *
117 * Returns 0 on failure, non-zero on success
118 */
119
120 #if defined(__GNUC__)
121
122 static __inline int
123 atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
124 {
125 int res = exp;
126
127 __asm __volatile (
128 " " __XSTRING(MPLOCKED) " "
129 " cmpxchgl %1,%2 ; "
130 " setz %%al ; "
131 " movzbl %%al,%0 ; "
132 "1: "
133 "# atomic_cmpset_int"
134 : "+a" (res) /* 0 (result) */
135 : "r" (src), /* 1 */
136 "m" (*(dst)) /* 2 */
137 : "memory");
138
139 return (res);
140 }
141
142 static __inline int
143 atomic_cmpset_long(volatile u_long *dst, u_long exp, u_long src)
144 {
145 long res = exp;
146
147 __asm __volatile (
148 " " __XSTRING(MPLOCKED) " "
149 " cmpxchgq %1,%2 ; "
150 " setz %%al ; "
151 " movzbq %%al,%0 ; "
152 "1: "
153 "# atomic_cmpset_long"
154 : "+a" (res) /* 0 (result) */
155 : "r" (src), /* 1 */
156 "m" (*(dst)) /* 2 */
157 : "memory");
158
159 return (res);
160 }
161 #endif /* defined(__GNUC__) */
162
163 #if defined(__GNUC__)
164
165 #define ATOMIC_STORE_LOAD(TYPE, LOP, SOP) \
166 static __inline u_##TYPE \
167 atomic_load_acq_##TYPE(volatile u_##TYPE *p) \
168 { \
169 u_##TYPE res; \
170 \
171 __asm __volatile(__XSTRING(MPLOCKED) LOP \
172 : "=a" (res), /* 0 (result) */\
173 "+m" (*p) /* 1 */ \
174 : : "memory"); \
175 \
176 return (res); \
177 } \
178 \
179 /* \
180 * The XCHG instruction asserts LOCK automagically. \
181 */ \
182 static __inline void \
183 atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
184 { \
185 __asm __volatile(SOP \
186 : "+m" (*p), /* 0 */ \
187 "+r" (v) /* 1 */ \
188 : : "memory"); \
189 } \
190 struct __hack
191
192 #else /* !defined(__GNUC__) */
193
194 extern int atomic_cmpset_int(volatile u_int *, u_int, u_int);
195 extern int atomic_cmpset_long(volatile u_long *, u_long, u_long);
196
197 #define ATOMIC_STORE_LOAD(TYPE, LOP, SOP) \
198 extern u_##TYPE atomic_load_acq_##TYPE(volatile u_##TYPE *p); \
199 extern void atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
200
201 #endif /* defined(__GNUC__) */
202
203 #endif /* KLD_MODULE */
204
205 ATOMIC_ASM(set, char, "orb %b1,%0", "iq", v);
206 ATOMIC_ASM(clear, char, "andb %b1,%0", "iq", ~v);
207 ATOMIC_ASM(add, char, "addb %b1,%0", "iq", v);
208 ATOMIC_ASM(subtract, char, "subb %b1,%0", "iq", v);
209
210 ATOMIC_ASM(set, short, "orw %w1,%0", "ir", v);
211 ATOMIC_ASM(clear, short, "andw %w1,%0", "ir", ~v);
212 ATOMIC_ASM(add, short, "addw %w1,%0", "ir", v);
213 ATOMIC_ASM(subtract, short, "subw %w1,%0", "ir", v);
214
215 ATOMIC_ASM(set, int, "orl %1,%0", "ir", v);
216 ATOMIC_ASM(clear, int, "andl %1,%0", "ir", ~v);
217 ATOMIC_ASM(add, int, "addl %1,%0", "ir", v);
218 ATOMIC_ASM(subtract, int, "subl %1,%0", "ir", v);
219
220 ATOMIC_ASM(set, long, "orq %1,%0", "ir", v);
221 ATOMIC_ASM(clear, long, "andq %1,%0", "ir", ~v);
222 ATOMIC_ASM(add, long, "addq %1,%0", "ir", v);
223 ATOMIC_ASM(subtract, long, "subq %1,%0", "ir", v);
224
225 ATOMIC_STORE_LOAD(char, "cmpxchgb %b0,%1", "xchgb %b1,%0");
226 ATOMIC_STORE_LOAD(short,"cmpxchgw %w0,%1", "xchgw %w1,%0");
227 ATOMIC_STORE_LOAD(int, "cmpxchgl %0,%1", "xchgl %1,%0");
228 ATOMIC_STORE_LOAD(long, "cmpxchgq %0,%1", "xchgq %1,%0");
229
230 #undef ATOMIC_ASM
231 #undef ATOMIC_STORE_LOAD
232
233 #define atomic_set_acq_char atomic_set_char
234 #define atomic_set_rel_char atomic_set_char
235 #define atomic_clear_acq_char atomic_clear_char
236 #define atomic_clear_rel_char atomic_clear_char
237 #define atomic_add_acq_char atomic_add_char
238 #define atomic_add_rel_char atomic_add_char
239 #define atomic_subtract_acq_char atomic_subtract_char
240 #define atomic_subtract_rel_char atomic_subtract_char
241
242 #define atomic_set_acq_short atomic_set_short
243 #define atomic_set_rel_short atomic_set_short
244 #define atomic_clear_acq_short atomic_clear_short
245 #define atomic_clear_rel_short atomic_clear_short
246 #define atomic_add_acq_short atomic_add_short
247 #define atomic_add_rel_short atomic_add_short
248 #define atomic_subtract_acq_short atomic_subtract_short
249 #define atomic_subtract_rel_short atomic_subtract_short
250
251 #define atomic_set_acq_int atomic_set_int
252 #define atomic_set_rel_int atomic_set_int
253 #define atomic_clear_acq_int atomic_clear_int
254 #define atomic_clear_rel_int atomic_clear_int
255 #define atomic_add_acq_int atomic_add_int
256 #define atomic_add_rel_int atomic_add_int
257 #define atomic_subtract_acq_int atomic_subtract_int
258 #define atomic_subtract_rel_int atomic_subtract_int
259 #define atomic_cmpset_acq_int atomic_cmpset_int
260 #define atomic_cmpset_rel_int atomic_cmpset_int
261
262 #define atomic_set_acq_long atomic_set_long
263 #define atomic_set_rel_long atomic_set_long
264 #define atomic_clear_acq_long atomic_clear_long
265 #define atomic_clear_rel_long atomic_clear_long
266 #define atomic_add_acq_long atomic_add_long
267 #define atomic_add_rel_long atomic_add_long
268 #define atomic_subtract_acq_long atomic_subtract_long
269 #define atomic_subtract_rel_long atomic_subtract_long
270
271 #define atomic_cmpset_acq_ptr atomic_cmpset_ptr
272 #define atomic_cmpset_rel_ptr atomic_cmpset_ptr
273
274 #define atomic_set_8 atomic_set_char
275 #define atomic_set_acq_8 atomic_set_acq_char
276 #define atomic_set_rel_8 atomic_set_rel_char
277 #define atomic_clear_8 atomic_clear_char
278 #define atomic_clear_acq_8 atomic_clear_acq_char
279 #define atomic_clear_rel_8 atomic_clear_rel_char
280 #define atomic_add_8 atomic_add_char
281 #define atomic_add_acq_8 atomic_add_acq_char
282 #define atomic_add_rel_8 atomic_add_rel_char
283 #define atomic_subtract_8 atomic_subtract_char
284 #define atomic_subtract_acq_8 atomic_subtract_acq_char
285 #define atomic_subtract_rel_8 atomic_subtract_rel_char
286 #define atomic_load_acq_8 atomic_load_acq_char
287 #define atomic_store_rel_8 atomic_store_rel_char
288
289 #define atomic_set_16 atomic_set_short
290 #define atomic_set_acq_16 atomic_set_acq_short
291 #define atomic_set_rel_16 atomic_set_rel_short
292 #define atomic_clear_16 atomic_clear_short
293 #define atomic_clear_acq_16 atomic_clear_acq_short
294 #define atomic_clear_rel_16 atomic_clear_rel_short
295 #define atomic_add_16 atomic_add_short
296 #define atomic_add_acq_16 atomic_add_acq_short
297 #define atomic_add_rel_16 atomic_add_rel_short
298 #define atomic_subtract_16 atomic_subtract_short
299 #define atomic_subtract_acq_16 atomic_subtract_acq_short
300 #define atomic_subtract_rel_16 atomic_subtract_rel_short
301 #define atomic_load_acq_16 atomic_load_acq_short
302 #define atomic_store_rel_16 atomic_store_rel_short
303
304 #define atomic_set_32 atomic_set_int
305 #define atomic_set_acq_32 atomic_set_acq_int
306 #define atomic_set_rel_32 atomic_set_rel_int
307 #define atomic_clear_32 atomic_clear_int
308 #define atomic_clear_acq_32 atomic_clear_acq_int
309 #define atomic_clear_rel_32 atomic_clear_rel_int
310 #define atomic_add_32 atomic_add_int
311 #define atomic_add_acq_32 atomic_add_acq_int
312 #define atomic_add_rel_32 atomic_add_rel_int
313 #define atomic_subtract_32 atomic_subtract_int
314 #define atomic_subtract_acq_32 atomic_subtract_acq_int
315 #define atomic_subtract_rel_32 atomic_subtract_rel_int
316 #define atomic_load_acq_32 atomic_load_acq_int
317 #define atomic_store_rel_32 atomic_store_rel_int
318 #define atomic_cmpset_32 atomic_cmpset_int
319 #define atomic_cmpset_acq_32 atomic_cmpset_acq_int
320 #define atomic_cmpset_rel_32 atomic_cmpset_rel_int
321 #define atomic_readandclear_32 atomic_readandclear_int
322
323 #if !defined(WANT_FUNCTIONS)
324 static __inline int
325 atomic_cmpset_ptr(volatile void *dst, void *exp, void *src)
326 {
327
328 return (atomic_cmpset_long((volatile u_long *)dst,
329 (u_long)exp, (u_long)src));
330 }
331
332 static __inline void *
333 atomic_load_acq_ptr(volatile void *p)
334 {
335 /*
336 * The apparently-bogus cast to intptr_t in the following is to
337 * avoid a warning from "gcc -Wbad-function-cast".
338 */
339 return ((void *)(intptr_t)atomic_load_acq_long((volatile u_long *)p));
340 }
341
342 static __inline void
343 atomic_store_rel_ptr(volatile void *p, void *v)
344 {
345 atomic_store_rel_long((volatile u_long *)p, (u_long)v);
346 }
347
348 #define ATOMIC_PTR(NAME) \
349 static __inline void \
350 atomic_##NAME##_ptr(volatile void *p, uintptr_t v) \
351 { \
352 atomic_##NAME##_long((volatile u_long *)p, v); \
353 } \
354 \
355 static __inline void \
356 atomic_##NAME##_acq_ptr(volatile void *p, uintptr_t v) \
357 { \
358 atomic_##NAME##_acq_long((volatile u_long *)p, v);\
359 } \
360 \
361 static __inline void \
362 atomic_##NAME##_rel_ptr(volatile void *p, uintptr_t v) \
363 { \
364 atomic_##NAME##_rel_long((volatile u_long *)p, v);\
365 }
366
367 ATOMIC_PTR(set)
368 ATOMIC_PTR(clear)
369 ATOMIC_PTR(add)
370 ATOMIC_PTR(subtract)
371
372 #undef ATOMIC_PTR
373
374 #if defined(__GNUC__)
375
376 static __inline u_int
377 atomic_readandclear_int(volatile u_int *addr)
378 {
379 u_int result;
380
381 __asm __volatile (
382 " xorl %0,%0 ; "
383 " xchgl %1,%0 ; "
384 "# atomic_readandclear_int"
385 : "=&r" (result) /* 0 (result) */
386 : "m" (*addr)); /* 1 (addr) */
387
388 return (result);
389 }
390
391 static __inline u_long
392 atomic_readandclear_long(volatile u_long *addr)
393 {
394 u_long result;
395
396 __asm __volatile (
397 " xorq %0,%0 ; "
398 " xchgq %1,%0 ; "
399 "# atomic_readandclear_int"
400 : "=&r" (result) /* 0 (result) */
401 : "m" (*addr)); /* 1 (addr) */
402
403 return (result);
404 }
405
406 #else /* !defined(__GNUC__) */
407
408 extern u_long atomic_readandclear_long(volatile u_long *);
409 extern u_int atomic_readandclear_int(volatile u_int *);
410
411 #endif /* defined(__GNUC__) */
412
413 #endif /* !defined(WANT_FUNCTIONS) */
414 #endif /* ! _MACHINE_ATOMIC_H_ */
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