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 * $FreeBSD$ 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) 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 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) 80 81 #else /* !KLD_MODULE */ 82 83 #if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE) 84 85 /* 86 * For userland, assume the SMP case and use lock prefixes so that 87 * the binaries will run on both types of systems. 88 */ 89 #if defined(SMP) || !defined(_KERNEL) 90 #define MPLOCKED lock ; 91 #else 92 #define MPLOCKED 93 #endif 94 95 /* 96 * The assembly is volatilized to demark potential before-and-after side 97 * effects if an interrupt or SMP collision were to occur. 98 */ 99 #define ATOMIC_ASM(NAME, TYPE, OP, CONS, V) \ 100 static __inline void \ 101 atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\ 102 { \ 103 __asm __volatile(__XSTRING(MPLOCKED) OP \ 104 : "+m" (*p) \ 105 : CONS (V)); \ 106 } \ 107 struct __hack 108 109 #else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */ 110 111 #define ATOMIC_ASM(NAME, TYPE, OP, CONS, V) \ 112 extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v) 113 114 #endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */ 115 116 /* 117 * Atomic compare and set, used by the mutex functions 118 * 119 * if (*dst == exp) *dst = src (all 32 bit words) 120 * 121 * Returns 0 on failure, non-zero on success 122 */ 123 124 #if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE) 125 126 static __inline int 127 atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src) 128 { 129 int res = exp; 130 131 __asm __volatile ( 132 " " __XSTRING(MPLOCKED) " " 133 " cmpxchgl %1,%2 ; " 134 " setz %%al ; " 135 " movzbl %%al,%0 ; " 136 "1: " 137 "# atomic_cmpset_int" 138 : "+a" (res) /* 0 (result) */ 139 : "r" (src), /* 1 */ 140 "m" (*(dst)) /* 2 */ 141 : "memory"); 142 143 return (res); 144 } 145 146 static __inline int 147 atomic_cmpset_long(volatile u_long *dst, u_long exp, u_long src) 148 { 149 long res = exp; 150 151 __asm __volatile ( 152 " " __XSTRING(MPLOCKED) " " 153 " cmpxchgq %1,%2 ; " 154 " setz %%al ; " 155 " movzbq %%al,%0 ; " 156 "1: " 157 "# atomic_cmpset_long" 158 : "+a" (res) /* 0 (result) */ 159 : "r" (src), /* 1 */ 160 "m" (*(dst)) /* 2 */ 161 : "memory"); 162 163 return (res); 164 } 165 #endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */ 166 167 #if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE) 168 169 #define ATOMIC_STORE_LOAD(TYPE, LOP, SOP) \ 170 static __inline u_##TYPE \ 171 atomic_load_acq_##TYPE(volatile u_##TYPE *p) \ 172 { \ 173 u_##TYPE res; \ 174 \ 175 __asm __volatile(__XSTRING(MPLOCKED) LOP \ 176 : "=a" (res), /* 0 (result) */\ 177 "+m" (*p) /* 1 */ \ 178 : : "memory"); \ 179 \ 180 return (res); \ 181 } \ 182 \ 183 /* \ 184 * The XCHG instruction asserts LOCK automagically. \ 185 */ \ 186 static __inline void \ 187 atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\ 188 { \ 189 __asm __volatile(SOP \ 190 : "+m" (*p), /* 0 */ \ 191 "+r" (v) /* 1 */ \ 192 : : "memory"); \ 193 } \ 194 struct __hack 195 196 #else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */ 197 198 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); 200 201 #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) 204 205 #endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */ 206 207 #endif /* KLD_MODULE */ 208 209 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); 213 214 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); 218 219 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); 223 224 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); 228 229 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"); 233 234 #undef ATOMIC_ASM 235 #undef ATOMIC_STORE_LOAD 236 237 #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 245 246 #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 254 255 #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 265 266 #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 274 275 #define atomic_cmpset_acq_ptr atomic_cmpset_ptr 276 #define atomic_cmpset_rel_ptr atomic_cmpset_ptr 277 278 #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 292 293 #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 307 308 #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 326 327 #if !defined(WANT_FUNCTIONS) 328 static __inline int 329 atomic_cmpset_ptr(volatile void *dst, void *exp, void *src) 330 { 331 332 return (atomic_cmpset_long((volatile u_long *)dst, 333 (u_long)exp, (u_long)src)); 334 } 335 336 static __inline void * 337 atomic_load_acq_ptr(volatile void *p) 338 { 339 /* 340 * The apparently-bogus cast to intptr_t in the following is to 341 * avoid a warning from "gcc -Wbad-function-cast". 342 */ 343 return ((void *)(intptr_t)atomic_load_acq_long((volatile u_long *)p)); 344 } 345 346 static __inline void 347 atomic_store_rel_ptr(volatile void *p, void *v) 348 { 349 atomic_store_rel_long((volatile u_long *)p, (u_long)v); 350 } 351 352 #define ATOMIC_PTR(NAME) \ 353 static __inline void \ 354 atomic_##NAME##_ptr(volatile void *p, uintptr_t v) \ 355 { \ 356 atomic_##NAME##_long((volatile u_long *)p, v); \ 357 } \ 358 \ 359 static __inline void \ 360 atomic_##NAME##_acq_ptr(volatile void *p, uintptr_t v) \ 361 { \ 362 atomic_##NAME##_acq_long((volatile u_long *)p, v);\ 363 } \ 364 \ 365 static __inline void \ 366 atomic_##NAME##_rel_ptr(volatile void *p, uintptr_t v) \ 367 { \ 368 atomic_##NAME##_rel_long((volatile u_long *)p, v);\ 369 } 370 371 ATOMIC_PTR(set) 372 ATOMIC_PTR(clear) 373 ATOMIC_PTR(add) 374 ATOMIC_PTR(subtract) 375 376 #undef ATOMIC_PTR 377 378 #if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE) 379 380 static __inline u_int 381 atomic_readandclear_int(volatile u_int *addr) 382 { 383 u_int result; 384 385 __asm __volatile ( 386 " xorl %0,%0 ; " 387 " xchgl %1,%0 ; " 388 "# atomic_readandclear_int" 389 : "=&r" (result) /* 0 (result) */ 390 : "m" (*addr)); /* 1 (addr) */ 391 392 return (result); 393 } 394 395 static __inline u_long 396 atomic_readandclear_long(volatile u_long *addr) 397 { 398 u_long result; 399 400 __asm __volatile ( 401 " xorq %0,%0 ; " 402 " xchgq %1,%0 ; " 403 "# atomic_readandclear_int" 404 : "=&r" (result) /* 0 (result) */ 405 : "m" (*addr)); /* 1 (addr) */ 406 407 return (result); 408 } 409 410 #else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */ 411 412 extern u_long atomic_readandclear_long(volatile u_long *); 413 extern u_int atomic_readandclear_int(volatile u_int *); 414 415 #endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */ 416 417 #endif /* !defined(WANT_FUNCTIONS) */ 418 #endif /* ! _MACHINE_ATOMIC_H_ */ 419