atomic.h revision 254611
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: head/sys/amd64/include/atomic.h 254611 2013-08-21 20:49:46Z jkim $ 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#define mb() __asm __volatile("mfence;" : : : "memory") 36#define wmb() __asm __volatile("sfence;" : : : "memory") 37#define rmb() __asm __volatile("lfence;" : : : "memory") 38 39/* 40 * Various simple operations on memory, each of which is atomic in the 41 * presence of interrupts and multiple processors. 42 * 43 * atomic_set_char(P, V) (*(u_char *)(P) |= (V)) 44 * atomic_clear_char(P, V) (*(u_char *)(P) &= ~(V)) 45 * atomic_add_char(P, V) (*(u_char *)(P) += (V)) 46 * atomic_subtract_char(P, V) (*(u_char *)(P) -= (V)) 47 * 48 * atomic_set_short(P, V) (*(u_short *)(P) |= (V)) 49 * atomic_clear_short(P, V) (*(u_short *)(P) &= ~(V)) 50 * atomic_add_short(P, V) (*(u_short *)(P) += (V)) 51 * atomic_subtract_short(P, V) (*(u_short *)(P) -= (V)) 52 * 53 * atomic_set_int(P, V) (*(u_int *)(P) |= (V)) 54 * atomic_clear_int(P, V) (*(u_int *)(P) &= ~(V)) 55 * atomic_add_int(P, V) (*(u_int *)(P) += (V)) 56 * atomic_subtract_int(P, V) (*(u_int *)(P) -= (V)) 57 * atomic_readandclear_int(P) (return (*(u_int *)(P)); *(u_int *)(P) = 0;) 58 * 59 * atomic_set_long(P, V) (*(u_long *)(P) |= (V)) 60 * atomic_clear_long(P, V) (*(u_long *)(P) &= ~(V)) 61 * atomic_add_long(P, V) (*(u_long *)(P) += (V)) 62 * atomic_subtract_long(P, V) (*(u_long *)(P) -= (V)) 63 * atomic_readandclear_long(P) (return (*(u_long *)(P)); *(u_long *)(P) = 0;) 64 */ 65 66/* 67 * The above functions are expanded inline in the statically-linked 68 * kernel. Lock prefixes are generated if an SMP kernel is being 69 * built. 70 * 71 * Kernel modules call real functions which are built into the kernel. 72 * This allows kernel modules to be portable between UP and SMP systems. 73 */ 74#if defined(KLD_MODULE) || !defined(__GNUCLIKE_ASM) 75#define ATOMIC_ASM(NAME, TYPE, OP, CONS, V) \ 76void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v); \ 77void atomic_##NAME##_barr_##TYPE(volatile u_##TYPE *p, u_##TYPE v) 78 79int atomic_cmpset_int(volatile u_int *dst, u_int expect, u_int src); 80int atomic_cmpset_long(volatile u_long *dst, u_long expect, u_long src); 81u_int atomic_fetchadd_int(volatile u_int *p, u_int v); 82u_long atomic_fetchadd_long(volatile u_long *p, u_long v); 83 84#define ATOMIC_LOAD(TYPE, LOP) \ 85u_##TYPE atomic_load_acq_##TYPE(volatile u_##TYPE *p) 86#define ATOMIC_STORE(TYPE) \ 87void atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v) 88 89#else /* !KLD_MODULE && __GNUCLIKE_ASM */ 90 91/* 92 * For userland, always use lock prefixes so that the binaries will run 93 * on both SMP and !SMP systems. 94 */ 95#if defined(SMP) || !defined(_KERNEL) 96#define MPLOCKED "lock ; " 97#else 98#define MPLOCKED 99#endif 100 101/* 102 * The assembly is volatilized to avoid code chunk removal by the compiler. 103 * GCC aggressively reorders operations and memory clobbering is necessary 104 * in order to avoid that for memory barriers. 105 */ 106#define ATOMIC_ASM(NAME, TYPE, OP, CONS, V) \ 107static __inline void \ 108atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\ 109{ \ 110 __asm __volatile(MPLOCKED OP \ 111 : "=m" (*p) \ 112 : CONS (V), "m" (*p) \ 113 : "cc"); \ 114} \ 115 \ 116static __inline void \ 117atomic_##NAME##_barr_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\ 118{ \ 119 __asm __volatile(MPLOCKED OP \ 120 : "=m" (*p) \ 121 : CONS (V), "m" (*p) \ 122 : "memory", "cc"); \ 123} \ 124struct __hack 125 126/* 127 * Atomic compare and set, used by the mutex functions 128 * 129 * if (*dst == expect) *dst = src (all 32 bit words) 130 * 131 * Returns 0 on failure, non-zero on success 132 */ 133 134static __inline int 135atomic_cmpset_int(volatile u_int *dst, u_int expect, u_int src) 136{ 137 u_char res; 138 139 __asm __volatile( 140 " " MPLOCKED " " 141 " cmpxchgl %2,%1 ; " 142 " sete %0 ; " 143 "# atomic_cmpset_int" 144 : "=a" (res), /* 0 */ 145 "=m" (*dst) /* 1 */ 146 : "r" (src), /* 2 */ 147 "a" (expect), /* 3 */ 148 "m" (*dst) /* 4 */ 149 : "memory", "cc"); 150 151 return (res); 152} 153 154static __inline int 155atomic_cmpset_long(volatile u_long *dst, u_long expect, u_long src) 156{ 157 u_char res; 158 159 __asm __volatile( 160 " " MPLOCKED " " 161 " cmpxchgq %2,%1 ; " 162 " sete %0 ; " 163 "# atomic_cmpset_long" 164 : "=a" (res), /* 0 */ 165 "=m" (*dst) /* 1 */ 166 : "r" (src), /* 2 */ 167 "a" (expect), /* 3 */ 168 "m" (*dst) /* 4 */ 169 : "memory", "cc"); 170 171 return (res); 172} 173 174/* 175 * Atomically add the value of v to the integer pointed to by p and return 176 * the previous value of *p. 177 */ 178static __inline u_int 179atomic_fetchadd_int(volatile u_int *p, u_int v) 180{ 181 182 __asm __volatile( 183 " " MPLOCKED " " 184 " xaddl %0,%1 ; " 185 "# atomic_fetchadd_int" 186 : "+r" (v), /* 0 */ 187 "=m" (*p) /* 1 */ 188 : "m" (*p) /* 2 */ 189 : "cc"); 190 return (v); 191} 192 193/* 194 * Atomically add the value of v to the long integer pointed to by p and return 195 * the previous value of *p. 196 */ 197static __inline u_long 198atomic_fetchadd_long(volatile u_long *p, u_long v) 199{ 200 201 __asm __volatile( 202 " " MPLOCKED " " 203 " xaddq %0,%1 ; " 204 "# atomic_fetchadd_long" 205 : "+r" (v), /* 0 */ 206 "=m" (*p) /* 1 */ 207 : "m" (*p) /* 2 */ 208 : "cc"); 209 return (v); 210} 211 212/* 213 * We assume that a = b will do atomic loads and stores. Due to the 214 * IA32 memory model, a simple store guarantees release semantics. 215 * 216 * However, loads may pass stores, so for atomic_load_acq we have to 217 * ensure a Store/Load barrier to do the load in SMP kernels. We use 218 * "lock cmpxchg" as recommended by the AMD Software Optimization 219 * Guide, and not mfence. For UP kernels, however, the cache of the 220 * single processor is always consistent, so we only need to take care 221 * of the compiler. 222 */ 223#define ATOMIC_STORE(TYPE) \ 224static __inline void \ 225atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\ 226{ \ 227 __compiler_membar(); \ 228 *p = v; \ 229} \ 230struct __hack 231 232#if defined(_KERNEL) && !defined(SMP) 233 234#define ATOMIC_LOAD(TYPE, LOP) \ 235static __inline u_##TYPE \ 236atomic_load_acq_##TYPE(volatile u_##TYPE *p) \ 237{ \ 238 u_##TYPE tmp; \ 239 \ 240 tmp = *p; \ 241 __compiler_membar(); \ 242 return (tmp); \ 243} \ 244struct __hack 245 246#else /* !(_KERNEL && !SMP) */ 247 248#define ATOMIC_LOAD(TYPE, LOP) \ 249static __inline u_##TYPE \ 250atomic_load_acq_##TYPE(volatile u_##TYPE *p) \ 251{ \ 252 u_##TYPE res; \ 253 \ 254 __asm __volatile(MPLOCKED LOP \ 255 : "=a" (res), /* 0 */ \ 256 "=m" (*p) /* 1 */ \ 257 : "m" (*p) /* 2 */ \ 258 : "memory", "cc"); \ 259 \ 260 return (res); \ 261} \ 262struct __hack 263 264#endif /* _KERNEL && !SMP */ 265 266#endif /* KLD_MODULE || !__GNUCLIKE_ASM */ 267 268ATOMIC_ASM(set, char, "orb %b1,%0", "iq", v); 269ATOMIC_ASM(clear, char, "andb %b1,%0", "iq", ~v); 270ATOMIC_ASM(add, char, "addb %b1,%0", "iq", v); 271ATOMIC_ASM(subtract, char, "subb %b1,%0", "iq", v); 272 273ATOMIC_ASM(set, short, "orw %w1,%0", "ir", v); 274ATOMIC_ASM(clear, short, "andw %w1,%0", "ir", ~v); 275ATOMIC_ASM(add, short, "addw %w1,%0", "ir", v); 276ATOMIC_ASM(subtract, short, "subw %w1,%0", "ir", v); 277 278ATOMIC_ASM(set, int, "orl %1,%0", "ir", v); 279ATOMIC_ASM(clear, int, "andl %1,%0", "ir", ~v); 280ATOMIC_ASM(add, int, "addl %1,%0", "ir", v); 281ATOMIC_ASM(subtract, int, "subl %1,%0", "ir", v); 282 283ATOMIC_ASM(set, long, "orq %1,%0", "ir", v); 284ATOMIC_ASM(clear, long, "andq %1,%0", "ir", ~v); 285ATOMIC_ASM(add, long, "addq %1,%0", "ir", v); 286ATOMIC_ASM(subtract, long, "subq %1,%0", "ir", v); 287 288ATOMIC_LOAD(char, "cmpxchgb %b0,%1"); 289ATOMIC_LOAD(short, "cmpxchgw %w0,%1"); 290ATOMIC_LOAD(int, "cmpxchgl %0,%1"); 291ATOMIC_LOAD(long, "cmpxchgq %0,%1"); 292 293ATOMIC_STORE(char); 294ATOMIC_STORE(short); 295ATOMIC_STORE(int); 296ATOMIC_STORE(long); 297 298#undef ATOMIC_ASM 299#undef ATOMIC_LOAD 300#undef ATOMIC_STORE 301 302#ifndef WANT_FUNCTIONS 303 304/* Read the current value and store a zero in the destination. */ 305#ifdef __GNUCLIKE_ASM 306 307static __inline u_int 308atomic_readandclear_int(volatile u_int *p) 309{ 310 u_int res; 311 312 res = 0; 313 __asm __volatile( 314 " xchgl %1,%0 ; " 315 "# atomic_readandclear_int" 316 : "+r" (res), /* 0 */ 317 "=m" (*p) /* 1 */ 318 : "m" (*p)); 319 320 return (res); 321} 322 323static __inline u_long 324atomic_readandclear_long(volatile u_long *p) 325{ 326 u_long res; 327 328 res = 0; 329 __asm __volatile( 330 " xchgq %1,%0 ; " 331 "# atomic_readandclear_long" 332 : "+r" (res), /* 0 */ 333 "=m" (*p) /* 1 */ 334 : "m" (*p)); 335 336 return (res); 337} 338 339#else /* !__GNUCLIKE_ASM */ 340 341u_int atomic_readandclear_int(volatile u_int *p); 342u_long atomic_readandclear_long(volatile u_long *p); 343 344#endif /* __GNUCLIKE_ASM */ 345 346#define atomic_set_acq_char atomic_set_barr_char 347#define atomic_set_rel_char atomic_set_barr_char 348#define atomic_clear_acq_char atomic_clear_barr_char 349#define atomic_clear_rel_char atomic_clear_barr_char 350#define atomic_add_acq_char atomic_add_barr_char 351#define atomic_add_rel_char atomic_add_barr_char 352#define atomic_subtract_acq_char atomic_subtract_barr_char 353#define atomic_subtract_rel_char atomic_subtract_barr_char 354 355#define atomic_set_acq_short atomic_set_barr_short 356#define atomic_set_rel_short atomic_set_barr_short 357#define atomic_clear_acq_short atomic_clear_barr_short 358#define atomic_clear_rel_short atomic_clear_barr_short 359#define atomic_add_acq_short atomic_add_barr_short 360#define atomic_add_rel_short atomic_add_barr_short 361#define atomic_subtract_acq_short atomic_subtract_barr_short 362#define atomic_subtract_rel_short atomic_subtract_barr_short 363 364#define atomic_set_acq_int atomic_set_barr_int 365#define atomic_set_rel_int atomic_set_barr_int 366#define atomic_clear_acq_int atomic_clear_barr_int 367#define atomic_clear_rel_int atomic_clear_barr_int 368#define atomic_add_acq_int atomic_add_barr_int 369#define atomic_add_rel_int atomic_add_barr_int 370#define atomic_subtract_acq_int atomic_subtract_barr_int 371#define atomic_subtract_rel_int atomic_subtract_barr_int 372#define atomic_cmpset_acq_int atomic_cmpset_int 373#define atomic_cmpset_rel_int atomic_cmpset_int 374 375#define atomic_set_acq_long atomic_set_barr_long 376#define atomic_set_rel_long atomic_set_barr_long 377#define atomic_clear_acq_long atomic_clear_barr_long 378#define atomic_clear_rel_long atomic_clear_barr_long 379#define atomic_add_acq_long atomic_add_barr_long 380#define atomic_add_rel_long atomic_add_barr_long 381#define atomic_subtract_acq_long atomic_subtract_barr_long 382#define atomic_subtract_rel_long atomic_subtract_barr_long 383#define atomic_cmpset_acq_long atomic_cmpset_long 384#define atomic_cmpset_rel_long atomic_cmpset_long 385 386/* Operations on 8-bit bytes. */ 387#define atomic_set_8 atomic_set_char 388#define atomic_set_acq_8 atomic_set_acq_char 389#define atomic_set_rel_8 atomic_set_rel_char 390#define atomic_clear_8 atomic_clear_char 391#define atomic_clear_acq_8 atomic_clear_acq_char 392#define atomic_clear_rel_8 atomic_clear_rel_char 393#define atomic_add_8 atomic_add_char 394#define atomic_add_acq_8 atomic_add_acq_char 395#define atomic_add_rel_8 atomic_add_rel_char 396#define atomic_subtract_8 atomic_subtract_char 397#define atomic_subtract_acq_8 atomic_subtract_acq_char 398#define atomic_subtract_rel_8 atomic_subtract_rel_char 399#define atomic_load_acq_8 atomic_load_acq_char 400#define atomic_store_rel_8 atomic_store_rel_char 401 402/* Operations on 16-bit words. */ 403#define atomic_set_16 atomic_set_short 404#define atomic_set_acq_16 atomic_set_acq_short 405#define atomic_set_rel_16 atomic_set_rel_short 406#define atomic_clear_16 atomic_clear_short 407#define atomic_clear_acq_16 atomic_clear_acq_short 408#define atomic_clear_rel_16 atomic_clear_rel_short 409#define atomic_add_16 atomic_add_short 410#define atomic_add_acq_16 atomic_add_acq_short 411#define atomic_add_rel_16 atomic_add_rel_short 412#define atomic_subtract_16 atomic_subtract_short 413#define atomic_subtract_acq_16 atomic_subtract_acq_short 414#define atomic_subtract_rel_16 atomic_subtract_rel_short 415#define atomic_load_acq_16 atomic_load_acq_short 416#define atomic_store_rel_16 atomic_store_rel_short 417 418/* Operations on 32-bit double words. */ 419#define atomic_set_32 atomic_set_int 420#define atomic_set_acq_32 atomic_set_acq_int 421#define atomic_set_rel_32 atomic_set_rel_int 422#define atomic_clear_32 atomic_clear_int 423#define atomic_clear_acq_32 atomic_clear_acq_int 424#define atomic_clear_rel_32 atomic_clear_rel_int 425#define atomic_add_32 atomic_add_int 426#define atomic_add_acq_32 atomic_add_acq_int 427#define atomic_add_rel_32 atomic_add_rel_int 428#define atomic_subtract_32 atomic_subtract_int 429#define atomic_subtract_acq_32 atomic_subtract_acq_int 430#define atomic_subtract_rel_32 atomic_subtract_rel_int 431#define atomic_load_acq_32 atomic_load_acq_int 432#define atomic_store_rel_32 atomic_store_rel_int 433#define atomic_cmpset_32 atomic_cmpset_int 434#define atomic_cmpset_acq_32 atomic_cmpset_acq_int 435#define atomic_cmpset_rel_32 atomic_cmpset_rel_int 436#define atomic_readandclear_32 atomic_readandclear_int 437#define atomic_fetchadd_32 atomic_fetchadd_int 438 439/* Operations on 64-bit quad words. */ 440#define atomic_set_64 atomic_set_long 441#define atomic_set_acq_64 atomic_set_acq_long 442#define atomic_set_rel_64 atomic_set_rel_long 443#define atomic_clear_64 atomic_clear_long 444#define atomic_clear_acq_64 atomic_clear_acq_long 445#define atomic_clear_rel_64 atomic_clear_rel_long 446#define atomic_add_64 atomic_add_long 447#define atomic_add_acq_64 atomic_add_acq_long 448#define atomic_add_rel_64 atomic_add_rel_long 449#define atomic_subtract_64 atomic_subtract_long 450#define atomic_subtract_acq_64 atomic_subtract_acq_long 451#define atomic_subtract_rel_64 atomic_subtract_rel_long 452#define atomic_load_acq_64 atomic_load_acq_long 453#define atomic_store_rel_64 atomic_store_rel_long 454#define atomic_cmpset_64 atomic_cmpset_long 455#define atomic_cmpset_acq_64 atomic_cmpset_acq_long 456#define atomic_cmpset_rel_64 atomic_cmpset_rel_long 457#define atomic_readandclear_64 atomic_readandclear_long 458 459/* Operations on pointers. */ 460#define atomic_set_ptr atomic_set_long 461#define atomic_set_acq_ptr atomic_set_acq_long 462#define atomic_set_rel_ptr atomic_set_rel_long 463#define atomic_clear_ptr atomic_clear_long 464#define atomic_clear_acq_ptr atomic_clear_acq_long 465#define atomic_clear_rel_ptr atomic_clear_rel_long 466#define atomic_add_ptr atomic_add_long 467#define atomic_add_acq_ptr atomic_add_acq_long 468#define atomic_add_rel_ptr atomic_add_rel_long 469#define atomic_subtract_ptr atomic_subtract_long 470#define atomic_subtract_acq_ptr atomic_subtract_acq_long 471#define atomic_subtract_rel_ptr atomic_subtract_rel_long 472#define atomic_load_acq_ptr atomic_load_acq_long 473#define atomic_store_rel_ptr atomic_store_rel_long 474#define atomic_cmpset_ptr atomic_cmpset_long 475#define atomic_cmpset_acq_ptr atomic_cmpset_acq_long 476#define atomic_cmpset_rel_ptr atomic_cmpset_rel_long 477#define atomic_readandclear_ptr atomic_readandclear_long 478 479#endif /* !WANT_FUNCTIONS */ 480 481#endif /* !_MACHINE_ATOMIC_H_ */ 482