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/6.0/sys/amd64/include/atomic.h 151008 2005-10-06 18:12:06Z jhb $
27 */
28 #ifndef _MACHINE_ATOMIC_H_
29 #define _MACHINE_ATOMIC_H_
30
31 #ifndef _SYS_CDEFS_H_
32 #error this file needs sys/cdefs.h as a prerequisite
33 #endif
34
35 /*
36 * Various simple arithmetic on memory which is atomic in the presence
37 * of interrupts and multiple processors.
38 *
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))
43 *
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))
48 *
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;)
54 *
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;)
60 */
61
62 /*
63 * The above functions are expanded inline in the statically-linked
64 * kernel. Lock prefixes are generated if an SMP kernel is being
65 * built.
66 *
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.
69 */
70 #if defined(KLD_MODULE) || !(defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE))
71 #define ATOMIC_ASM(NAME, TYPE, OP, CONS, V) \
72 void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
73
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);
76 u_int atomic_fetchadd_int(volatile u_int *p, u_int v);
77
78 #define ATOMIC_STORE_LOAD(TYPE, LOP, SOP) \
79 u_##TYPE atomic_load_acq_##TYPE(volatile u_##TYPE *p); \
80 void atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
81
82 #else /* !KLD_MODULE && __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
83
84 /*
85 * For userland, assume the SMP case and use lock prefixes so that
86 * the binaries will run on both types of systems.
87 */
88 #if defined(SMP) || !defined(_KERNEL)
89 #define MPLOCKED lock ;
90 #else
91 #define MPLOCKED
92 #endif
93
94 /*
95 * The assembly is volatilized to demark potential before-and-after side
96 * effects if an interrupt or SMP collision were to occur.
97 */
98 #define ATOMIC_ASM(NAME, TYPE, OP, CONS, V) \
99 static __inline void \
100 atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
101 { \
102 __asm __volatile(__XSTRING(MPLOCKED) OP \
103 : "=m" (*p) \
104 : CONS (V), "m" (*p)); \
105 } \
106 struct __hack
107
108 /*
109 * Atomic compare and set, used by the mutex functions
110 *
111 * if (*dst == exp) *dst = src (all 32 bit words)
112 *
113 * Returns 0 on failure, non-zero on success
114 */
115
116 static __inline int
117 atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
118 {
119 int res = exp;
120
121 __asm __volatile (
122 " " __XSTRING(MPLOCKED) " "
123 " cmpxchgl %2,%1 ; "
124 " setz %%al ; "
125 " movzbl %%al,%0 ; "
126 "1: "
127 "# atomic_cmpset_int"
128 : "+a" (res), /* 0 (result) */
129 "=m" (*dst) /* 1 */
130 : "r" (src), /* 2 */
131 "m" (*dst) /* 3 */
132 : "memory");
133
134 return (res);
135 }
136
137 static __inline int
138 atomic_cmpset_long(volatile u_long *dst, u_long exp, u_long src)
139 {
140 long res = exp;
141
142 __asm __volatile (
143 " " __XSTRING(MPLOCKED) " "
144 " cmpxchgq %2,%1 ; "
145 " setz %%al ; "
146 " movzbq %%al,%0 ; "
147 "1: "
148 "# atomic_cmpset_long"
149 : "+a" (res), /* 0 (result) */
150 "=m" (*dst) /* 1 */
151 : "r" (src), /* 2 */
152 "m" (*dst) /* 3 */
153 : "memory");
154
155 return (res);
156 }
157
158 /*
159 * Atomically add the value of v to the integer pointed to by p and return
160 * the previous value of *p.
161 */
162 static __inline u_int
163 atomic_fetchadd_int(volatile u_int *p, u_int v)
164 {
165
166 __asm __volatile (
167 " " __XSTRING(MPLOCKED) " "
168 " xaddl %0, %1 ; "
169 "# atomic_fetchadd_int"
170 : "+r" (v), /* 0 (result) */
171 "=m" (*p) /* 1 */
172 : "m" (*p)); /* 2 */
173
174 return (v);
175 }
176
177 #define ATOMIC_STORE_LOAD(TYPE, LOP, SOP) \
178 static __inline u_##TYPE \
179 atomic_load_acq_##TYPE(volatile u_##TYPE *p) \
180 { \
181 u_##TYPE res; \
182 \
183 __asm __volatile(__XSTRING(MPLOCKED) LOP \
184 : "=a" (res), /* 0 (result) */\
185 "=m" (*p) /* 1 */ \
186 : "m" (*p) /* 2 */ \
187 : "memory"); \
188 \
189 return (res); \
190 } \
191 \
192 /* \
193 * The XCHG instruction asserts LOCK automagically. \
194 */ \
195 static __inline void \
196 atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
197 { \
198 __asm __volatile(SOP \
199 : "=m" (*p), /* 0 */ \
200 "+r" (v) /* 1 */ \
201 : "m" (*p)); /* 2 */ \
202 } \
203 struct __hack
204
205 #endif /* KLD_MODULE || !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
206
207 ATOMIC_ASM(set, char, "orb %b1,%0", "iq", v);
208 ATOMIC_ASM(clear, char, "andb %b1,%0", "iq", ~v);
209 ATOMIC_ASM(add, char, "addb %b1,%0", "iq", v);
210 ATOMIC_ASM(subtract, char, "subb %b1,%0", "iq", v);
211
212 ATOMIC_ASM(set, short, "orw %w1,%0", "ir", v);
213 ATOMIC_ASM(clear, short, "andw %w1,%0", "ir", ~v);
214 ATOMIC_ASM(add, short, "addw %w1,%0", "ir", v);
215 ATOMIC_ASM(subtract, short, "subw %w1,%0", "ir", v);
216
217 ATOMIC_ASM(set, int, "orl %1,%0", "ir", v);
218 ATOMIC_ASM(clear, int, "andl %1,%0", "ir", ~v);
219 ATOMIC_ASM(add, int, "addl %1,%0", "ir", v);
220 ATOMIC_ASM(subtract, int, "subl %1,%0", "ir", v);
221
222 ATOMIC_ASM(set, long, "orq %1,%0", "ir", v);
223 ATOMIC_ASM(clear, long, "andq %1,%0", "ir", ~v);
224 ATOMIC_ASM(add, long, "addq %1,%0", "ir", v);
225 ATOMIC_ASM(subtract, long, "subq %1,%0", "ir", v);
226
227 ATOMIC_STORE_LOAD(char, "cmpxchgb %b0,%1", "xchgb %b1,%0");
228 ATOMIC_STORE_LOAD(short,"cmpxchgw %w0,%1", "xchgw %w1,%0");
229 ATOMIC_STORE_LOAD(int, "cmpxchgl %0,%1", "xchgl %1,%0");
230 ATOMIC_STORE_LOAD(long, "cmpxchgq %0,%1", "xchgq %1,%0");
231
232 #undef ATOMIC_ASM
233 #undef ATOMIC_STORE_LOAD
234
235 #if !defined(WANT_FUNCTIONS)
236
237 /* Read the current value and store a zero in the destination. */
238 #if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
239
240 static __inline u_int
241 atomic_readandclear_int(volatile u_int *addr)
242 {
243 u_int result;
244
245 result = 0;
246 __asm __volatile (
247 " xchgl %1,%0 ; "
248 "# atomic_readandclear_int"
249 : "+r" (result), /* 0 (result) */
250 "=m" (*addr) /* 1 (addr) */
251 : "m" (*addr));
252
253 return (result);
254 }
255
256 static __inline u_long
257 atomic_readandclear_long(volatile u_long *addr)
258 {
259 u_long result;
260
261 result = 0;
262 __asm __volatile (
263 " xchgq %1,%0 ; "
264 "# atomic_readandclear_long"
265 : "+r" (result), /* 0 (result) */
266 "=m" (*addr) /* 1 (addr) */
267 : "m" (*addr));
268
269 return (result);
270 }
271
272 #else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
273
274 u_int atomic_readandclear_int(volatile u_int *);
275 u_long atomic_readandclear_long(volatile u_long *);
276
277 #endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
278
279 /* Acquire and release variants are identical to the normal ones. */
280 #define atomic_set_acq_char atomic_set_char
281 #define atomic_set_rel_char atomic_set_char
282 #define atomic_clear_acq_char atomic_clear_char
283 #define atomic_clear_rel_char atomic_clear_char
284 #define atomic_add_acq_char atomic_add_char
285 #define atomic_add_rel_char atomic_add_char
286 #define atomic_subtract_acq_char atomic_subtract_char
287 #define atomic_subtract_rel_char atomic_subtract_char
288
289 #define atomic_set_acq_short atomic_set_short
290 #define atomic_set_rel_short atomic_set_short
291 #define atomic_clear_acq_short atomic_clear_short
292 #define atomic_clear_rel_short atomic_clear_short
293 #define atomic_add_acq_short atomic_add_short
294 #define atomic_add_rel_short atomic_add_short
295 #define atomic_subtract_acq_short atomic_subtract_short
296 #define atomic_subtract_rel_short atomic_subtract_short
297
298 #define atomic_set_acq_int atomic_set_int
299 #define atomic_set_rel_int atomic_set_int
300 #define atomic_clear_acq_int atomic_clear_int
301 #define atomic_clear_rel_int atomic_clear_int
302 #define atomic_add_acq_int atomic_add_int
303 #define atomic_add_rel_int atomic_add_int
304 #define atomic_subtract_acq_int atomic_subtract_int
305 #define atomic_subtract_rel_int atomic_subtract_int
306 #define atomic_cmpset_acq_int atomic_cmpset_int
307 #define atomic_cmpset_rel_int atomic_cmpset_int
308
309 #define atomic_set_acq_long atomic_set_long
310 #define atomic_set_rel_long atomic_set_long
311 #define atomic_clear_acq_long atomic_clear_long
312 #define atomic_clear_rel_long atomic_clear_long
313 #define atomic_add_acq_long atomic_add_long
314 #define atomic_add_rel_long atomic_add_long
315 #define atomic_subtract_acq_long atomic_subtract_long
316 #define atomic_subtract_rel_long atomic_subtract_long
317 #define atomic_cmpset_acq_long atomic_cmpset_long
318 #define atomic_cmpset_rel_long atomic_cmpset_long
319
320 /* Operations on 8-bit bytes. */
321 #define atomic_set_8 atomic_set_char
322 #define atomic_set_acq_8 atomic_set_acq_char
323 #define atomic_set_rel_8 atomic_set_rel_char
324 #define atomic_clear_8 atomic_clear_char
325 #define atomic_clear_acq_8 atomic_clear_acq_char
326 #define atomic_clear_rel_8 atomic_clear_rel_char
327 #define atomic_add_8 atomic_add_char
328 #define atomic_add_acq_8 atomic_add_acq_char
329 #define atomic_add_rel_8 atomic_add_rel_char
330 #define atomic_subtract_8 atomic_subtract_char
331 #define atomic_subtract_acq_8 atomic_subtract_acq_char
332 #define atomic_subtract_rel_8 atomic_subtract_rel_char
333 #define atomic_load_acq_8 atomic_load_acq_char
334 #define atomic_store_rel_8 atomic_store_rel_char
335
336 /* Operations on 16-bit words. */
337 #define atomic_set_16 atomic_set_short
338 #define atomic_set_acq_16 atomic_set_acq_short
339 #define atomic_set_rel_16 atomic_set_rel_short
340 #define atomic_clear_16 atomic_clear_short
341 #define atomic_clear_acq_16 atomic_clear_acq_short
342 #define atomic_clear_rel_16 atomic_clear_rel_short
343 #define atomic_add_16 atomic_add_short
344 #define atomic_add_acq_16 atomic_add_acq_short
345 #define atomic_add_rel_16 atomic_add_rel_short
346 #define atomic_subtract_16 atomic_subtract_short
347 #define atomic_subtract_acq_16 atomic_subtract_acq_short
348 #define atomic_subtract_rel_16 atomic_subtract_rel_short
349 #define atomic_load_acq_16 atomic_load_acq_short
350 #define atomic_store_rel_16 atomic_store_rel_short
351
352 /* Operations on 32-bit double words. */
353 #define atomic_set_32 atomic_set_int
354 #define atomic_set_acq_32 atomic_set_acq_int
355 #define atomic_set_rel_32 atomic_set_rel_int
356 #define atomic_clear_32 atomic_clear_int
357 #define atomic_clear_acq_32 atomic_clear_acq_int
358 #define atomic_clear_rel_32 atomic_clear_rel_int
359 #define atomic_add_32 atomic_add_int
360 #define atomic_add_acq_32 atomic_add_acq_int
361 #define atomic_add_rel_32 atomic_add_rel_int
362 #define atomic_subtract_32 atomic_subtract_int
363 #define atomic_subtract_acq_32 atomic_subtract_acq_int
364 #define atomic_subtract_rel_32 atomic_subtract_rel_int
365 #define atomic_load_acq_32 atomic_load_acq_int
366 #define atomic_store_rel_32 atomic_store_rel_int
367 #define atomic_cmpset_32 atomic_cmpset_int
368 #define atomic_cmpset_acq_32 atomic_cmpset_acq_int
369 #define atomic_cmpset_rel_32 atomic_cmpset_rel_int
370 #define atomic_readandclear_32 atomic_readandclear_int
371 #define atomic_fetchadd_32 atomic_fetchadd_int
372
373 /* Operations on 64-bit quad words. */
374 #define atomic_set_64 atomic_set_long
375 #define atomic_set_acq_64 atomic_set_acq_long
376 #define atomic_set_rel_64 atomic_set_rel_long
377 #define atomic_clear_64 atomic_clear_long
378 #define atomic_clear_acq_64 atomic_clear_acq_long
379 #define atomic_clear_rel_64 atomic_clear_rel_long
380 #define atomic_add_64 atomic_add_long
381 #define atomic_add_acq_64 atomic_add_acq_long
382 #define atomic_add_rel_64 atomic_add_rel_long
383 #define atomic_subtract_64 atomic_subtract_long
384 #define atomic_subtract_acq_64 atomic_subtract_acq_long
385 #define atomic_subtract_rel_64 atomic_subtract_rel_long
386 #define atomic_load_acq_64 atomic_load_acq_long
387 #define atomic_store_rel_64 atomic_store_rel_long
388 #define atomic_cmpset_64 atomic_cmpset_long
389 #define atomic_cmpset_acq_64 atomic_cmpset_acq_long
390 #define atomic_cmpset_rel_64 atomic_cmpset_rel_long
391 #define atomic_readandclear_64 atomic_readandclear_long
392
393 /* Operations on pointers. */
394 #define atomic_set_ptr atomic_set_long
395 #define atomic_set_acq_ptr atomic_set_acq_long
396 #define atomic_set_rel_ptr atomic_set_rel_long
397 #define atomic_clear_ptr atomic_clear_long
398 #define atomic_clear_acq_ptr atomic_clear_acq_long
399 #define atomic_clear_rel_ptr atomic_clear_rel_long
400 #define atomic_add_ptr atomic_add_long
401 #define atomic_add_acq_ptr atomic_add_acq_long
402 #define atomic_add_rel_ptr atomic_add_rel_long
403 #define atomic_subtract_ptr atomic_subtract_long
404 #define atomic_subtract_acq_ptr atomic_subtract_acq_long
405 #define atomic_subtract_rel_ptr atomic_subtract_rel_long
406 #define atomic_load_acq_ptr atomic_load_acq_long
407 #define atomic_store_rel_ptr atomic_store_rel_long
408 #define atomic_cmpset_ptr atomic_cmpset_long
409 #define atomic_cmpset_acq_ptr atomic_cmpset_acq_long
410 #define atomic_cmpset_rel_ptr atomic_cmpset_rel_long
411 #define atomic_readandclear_ptr atomic_readandclear_long
412
413 #endif /* !defined(WANT_FUNCTIONS) */
414 #endif /* ! _MACHINE_ATOMIC_H_ */
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