1/*- 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2013-2018 Mellanox Technologies, Ltd. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice unmodified, this list of conditions, and the following 13 * disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * 29 * $FreeBSD$ 30 */ 31 32#ifndef _ASM_ATOMIC_H_ 33#define _ASM_ATOMIC_H_ 34 35#include <linux/compiler.h> 36#include <sys/types.h> 37#include <machine/atomic.h> 38 39#define ATOMIC_INIT(x) { .counter = (x) } 40 41typedef struct { 42 volatile int counter; 43} atomic_t; 44 45/*------------------------------------------------------------------------* 46 * 32-bit atomic operations 47 *------------------------------------------------------------------------*/ 48 49#define atomic_add(i, v) atomic_add_return((i), (v)) 50#define atomic_sub(i, v) atomic_sub_return((i), (v)) 51#define atomic_inc_return(v) atomic_add_return(1, (v)) 52#define atomic_add_negative(i, v) (atomic_add_return((i), (v)) < 0) 53#define atomic_add_and_test(i, v) (atomic_add_return((i), (v)) == 0) 54#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0) 55#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) 56#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0) 57#define atomic_dec_return(v) atomic_sub_return(1, (v)) 58#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) 59 60static inline int 61atomic_add_return(int i, atomic_t *v) 62{ 63 return i + atomic_fetchadd_int(&v->counter, i); 64} 65 66static inline int 67atomic_sub_return(int i, atomic_t *v) 68{ 69 return atomic_fetchadd_int(&v->counter, -i) - i; 70} 71 72static inline void 73atomic_set(atomic_t *v, int i) 74{ 75 WRITE_ONCE(v->counter, i); 76} 77 78static inline void 79atomic_set_release(atomic_t *v, int i) 80{ 81 atomic_store_rel_int(&v->counter, i); 82} 83 84static inline void 85atomic_set_mask(unsigned int mask, atomic_t *v) 86{ 87 atomic_set_int(&v->counter, mask); 88} 89 90static inline int 91atomic_read(const atomic_t *v) 92{ 93 return READ_ONCE(v->counter); 94} 95 96static inline int 97atomic_inc(atomic_t *v) 98{ 99 return atomic_fetchadd_int(&v->counter, 1) + 1; 100} 101 102static inline int 103atomic_dec(atomic_t *v) 104{ 105 return atomic_fetchadd_int(&v->counter, -1) - 1; 106} 107 108static inline int 109atomic_add_unless(atomic_t *v, int a, int u) 110{ 111 int c = atomic_read(v); 112 113 for (;;) { 114 if (unlikely(c == u)) 115 break; 116 if (likely(atomic_fcmpset_int(&v->counter, &c, c + a))) 117 break; 118 } 119 return (c != u); 120} 121 122static inline int 123atomic_fetch_add_unless(atomic_t *v, int a, int u) 124{ 125 int c = atomic_read(v); 126 127 for (;;) { 128 if (unlikely(c == u)) 129 break; 130 if (likely(atomic_fcmpset_int(&v->counter, &c, c + a))) 131 break; 132 } 133 return (c); 134} 135 136static inline void 137atomic_clear_mask(unsigned int mask, atomic_t *v) 138{ 139 atomic_clear_int(&v->counter, mask); 140} 141 142static inline int 143atomic_xchg(atomic_t *v, int i) 144{ 145#if !defined(__mips__) 146 return (atomic_swap_int(&v->counter, i)); 147#else 148 int ret = atomic_read(v); 149 150 while (!atomic_fcmpset_int(&v->counter, &ret, i)) 151 ; 152 return (ret); 153#endif 154} 155 156static inline int 157atomic_cmpxchg(atomic_t *v, int old, int new) 158{ 159 int ret = old; 160 161 for (;;) { 162 if (atomic_fcmpset_int(&v->counter, &ret, new)) 163 break; 164 if (ret != old) 165 break; 166 } 167 return (ret); 168} 169 170#if defined(__amd64__) || defined(__arm64__) || defined(__i386__) 171#define LINUXKPI_ATOMIC_8(...) __VA_ARGS__ 172#define LINUXKPI_ATOMIC_16(...) __VA_ARGS__ 173#else 174#define LINUXKPI_ATOMIC_8(...) 175#define LINUXKPI_ATOMIC_16(...) 176#endif 177 178#if !(defined(i386) || (defined(__mips__) && !(defined(__mips_n32) || \ 179 defined(__mips_n64))) || (defined(__powerpc__) && \ 180 !defined(__powerpc64__))) 181#define LINUXKPI_ATOMIC_64(...) __VA_ARGS__ 182#else 183#define LINUXKPI_ATOMIC_64(...) 184#endif 185 186#define cmpxchg(ptr, old, new) ({ \ 187 union { \ 188 __typeof(*(ptr)) val; \ 189 u8 u8[0]; \ 190 u16 u16[0]; \ 191 u32 u32[0]; \ 192 u64 u64[0]; \ 193 } __ret = { .val = (old) }, __new = { .val = (new) }; \ 194 \ 195 CTASSERT( \ 196 LINUXKPI_ATOMIC_8(sizeof(__ret.val) == 1 ||) \ 197 LINUXKPI_ATOMIC_16(sizeof(__ret.val) == 2 ||) \ 198 LINUXKPI_ATOMIC_64(sizeof(__ret.val) == 8 ||) \ 199 sizeof(__ret.val) == 4); \ 200 \ 201 switch (sizeof(__ret.val)) { \ 202 LINUXKPI_ATOMIC_8( \ 203 case 1: \ 204 while (!atomic_fcmpset_8((volatile u8 *)(ptr), \ 205 __ret.u8, __new.u8[0]) && __ret.val == (old)) \ 206 ; \ 207 break; \ 208 ) \ 209 LINUXKPI_ATOMIC_16( \ 210 case 2: \ 211 while (!atomic_fcmpset_16((volatile u16 *)(ptr), \ 212 __ret.u16, __new.u16[0]) && __ret.val == (old)) \ 213 ; \ 214 break; \ 215 ) \ 216 case 4: \ 217 while (!atomic_fcmpset_32((volatile u32 *)(ptr), \ 218 __ret.u32, __new.u32[0]) && __ret.val == (old)) \ 219 ; \ 220 break; \ 221 LINUXKPI_ATOMIC_64( \ 222 case 8: \ 223 while (!atomic_fcmpset_64((volatile u64 *)(ptr), \ 224 __ret.u64, __new.u64[0]) && __ret.val == (old)) \ 225 ; \ 226 break; \ 227 ) \ 228 } \ 229 __ret.val; \ 230}) 231 232#define cmpxchg_relaxed(...) cmpxchg(__VA_ARGS__) 233 234#define xchg(ptr, new) ({ \ 235 union { \ 236 __typeof(*(ptr)) val; \ 237 u8 u8[0]; \ 238 u16 u16[0]; \ 239 u32 u32[0]; \ 240 u64 u64[0]; \ 241 } __ret, __new = { .val = (new) }; \ 242 \ 243 CTASSERT( \ 244 LINUXKPI_ATOMIC_8(sizeof(__ret.val) == 1 ||) \ 245 LINUXKPI_ATOMIC_16(sizeof(__ret.val) == 2 ||) \ 246 LINUXKPI_ATOMIC_64(sizeof(__ret.val) == 8 ||) \ 247 sizeof(__ret.val) == 4); \ 248 \ 249 switch (sizeof(__ret.val)) { \ 250 LINUXKPI_ATOMIC_8( \ 251 case 1: \ 252 __ret.val = READ_ONCE(*ptr); \ 253 while (!atomic_fcmpset_8((volatile u8 *)(ptr), \ 254 __ret.u8, __new.u8[0])) \ 255 ; \ 256 break; \ 257 ) \ 258 LINUXKPI_ATOMIC_16( \ 259 case 2: \ 260 __ret.val = READ_ONCE(*ptr); \ 261 while (!atomic_fcmpset_16((volatile u16 *)(ptr), \ 262 __ret.u16, __new.u16[0])) \ 263 ; \ 264 break; \ 265 ) \ 266 case 4: \ 267 __ret.u32[0] = atomic_swap_32((volatile u32 *)(ptr), \ 268 __new.u32[0]); \ 269 break; \ 270 LINUXKPI_ATOMIC_64( \ 271 case 8: \ 272 __ret.u64[0] = atomic_swap_64((volatile u64 *)(ptr), \ 273 __new.u64[0]); \ 274 break; \ 275 ) \ 276 } \ 277 __ret.val; \ 278}) 279 280static inline int 281atomic_dec_if_positive(atomic_t *v) 282{ 283 int retval; 284 int old; 285 286 old = atomic_read(v); 287 for (;;) { 288 retval = old - 1; 289 if (unlikely(retval < 0)) 290 break; 291 if (likely(atomic_fcmpset_int(&v->counter, &old, retval))) 292 break; 293 } 294 return (retval); 295} 296 297#define LINUX_ATOMIC_OP(op, c_op) \ 298static inline void atomic_##op(int i, atomic_t *v) \ 299{ \ 300 int c, old; \ 301 \ 302 c = v->counter; \ 303 while ((old = atomic_cmpxchg(v, c, c c_op i)) != c) \ 304 c = old; \ 305} 306 307#define LINUX_ATOMIC_FETCH_OP(op, c_op) \ 308static inline int atomic_fetch_##op(int i, atomic_t *v) \ 309{ \ 310 int c, old; \ 311 \ 312 c = v->counter; \ 313 while ((old = atomic_cmpxchg(v, c, c c_op i)) != c) \ 314 c = old; \ 315 \ 316 return (c); \ 317} 318 319LINUX_ATOMIC_OP(or, |) 320LINUX_ATOMIC_OP(and, &) 321LINUX_ATOMIC_OP(andnot, &~) 322LINUX_ATOMIC_OP(xor, ^) 323 324LINUX_ATOMIC_FETCH_OP(or, |) 325LINUX_ATOMIC_FETCH_OP(and, &) 326LINUX_ATOMIC_FETCH_OP(andnot, &~) 327LINUX_ATOMIC_FETCH_OP(xor, ^) 328 329#endif /* _ASM_ATOMIC_H_ */ 330