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 _LINUXKPI_ASM_ATOMIC_H_ 33 #define _LINUXKPI_ASM_ATOMIC_H_ 34 35 #include <linux/compiler.h> 36 #include <sys/types.h> 37 #include <machine/atomic.h> 38 #define ATOMIC_INIT(x) { .counter = (x) } 39 40 typedef struct { 41 volatile int counter; 42 } atomic_t; 43 44 /*------------------------------------------------------------------------* 45 * 32-bit atomic operations 46 *------------------------------------------------------------------------*/ 47 48 #define atomic_add(i, v) atomic_add_return((i), (v)) 49 #define atomic_sub(i, v) atomic_sub_return((i), (v)) 50 #define atomic_inc_return(v) atomic_add_return(1, (v)) 51 #define atomic_add_negative(i, v) (atomic_add_return((i), (v)) < 0) 52 #define atomic_add_and_test(i, v) (atomic_add_return((i), (v)) == 0) 53 #define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0) 54 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) 55 #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0) 56 #define atomic_dec_return(v) atomic_sub_return(1, (v)) 57 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) 58 59 static inline int 60 atomic_add_return(int i, atomic_t *v) 61 { 62 return i + atomic_fetchadd_int(&v->counter, i); 63 } 64 65 static inline int 66 atomic_sub_return(int i, atomic_t *v) 67 { 68 return atomic_fetchadd_int(&v->counter, -i) - i; 69 } 70 71 static inline void 72 atomic_set(atomic_t *v, int i) 73 { 74 WRITE_ONCE(v->counter, i); 75 } 76 77 static inline void 78 atomic_set_release(atomic_t *v, int i) 79 { 80 atomic_store_rel_int(&v->counter, i); 81 } 82 83 static inline void 84 atomic_set_mask(unsigned int mask, atomic_t *v) 85 { 86 atomic_set_int(&v->counter, mask); 87 } 88 89 static inline int 90 atomic_read(const atomic_t *v) 91 { 92 return READ_ONCE(v->counter); 93 } 94 95 static inline int 96 atomic_inc(atomic_t *v) 97 { 98 return atomic_fetchadd_int(&v->counter, 1) + 1; 99 } 100 101 static inline int 102 atomic_dec(atomic_t *v) 103 { 104 return atomic_fetchadd_int(&v->counter, -1) - 1; 105 } 106 107 static inline int 108 atomic_add_unless(atomic_t *v, int a, int u) 109 { 110 int c = atomic_read(v); 111 112 for (;;) { 113 if (unlikely(c == u)) 114 break; 115 if (likely(atomic_fcmpset_int(&v->counter, &c, c + a))) 116 break; 117 } 118 return (c != u); 119 } 120 121 static inline int 122 atomic_fetch_add_unless(atomic_t *v, int a, int u) 123 { 124 int c = atomic_read(v); 125 126 for (;;) { 127 if (unlikely(c == u)) 128 break; 129 if (likely(atomic_fcmpset_int(&v->counter, &c, c + a))) 130 break; 131 } 132 return (c); 133 } 134 135 static inline void 136 atomic_clear_mask(unsigned int mask, atomic_t *v) 137 { 138 atomic_clear_int(&v->counter, mask); 139 } 140 141 static inline int 142 atomic_xchg(atomic_t *v, int i) 143 { 144 return (atomic_swap_int(&v->counter, i)); 145 } 146 147 static inline int 148 atomic_cmpxchg(atomic_t *v, int old, int new) 149 { 150 int ret = old; 151 152 for (;;) { 153 if (atomic_fcmpset_int(&v->counter, &ret, new)) 154 break; 155 if (ret != old) 156 break; 157 } 158 return (ret); 159 } 160 161 #if defined(__amd64__) || defined(__arm64__) || defined(__i386__) 162 #define LINUXKPI_ATOMIC_8(...) __VA_ARGS__ 163 #define LINUXKPI_ATOMIC_16(...) __VA_ARGS__ 164 #else 165 #define LINUXKPI_ATOMIC_8(...) 166 #define LINUXKPI_ATOMIC_16(...) 167 #endif 168 169 #if !(defined(i386) || (defined(__powerpc__) && !defined(__powerpc64__))) 170 #define LINUXKPI_ATOMIC_64(...) __VA_ARGS__ 171 #else 172 #define LINUXKPI_ATOMIC_64(...) 173 #endif 174 175 #define cmpxchg(ptr, old, new) ({ \ 176 union { \ 177 __typeof(*(ptr)) val; \ 178 u8 u8[0]; \ 179 u16 u16[0]; \ 180 u32 u32[0]; \ 181 u64 u64[0]; \ 182 } __ret = { .val = (old) }, __new = { .val = (new) }; \ 183 \ 184 CTASSERT( \ 185 LINUXKPI_ATOMIC_8(sizeof(__ret.val) == 1 ||) \ 186 LINUXKPI_ATOMIC_16(sizeof(__ret.val) == 2 ||) \ 187 LINUXKPI_ATOMIC_64(sizeof(__ret.val) == 8 ||) \ 188 sizeof(__ret.val) == 4); \ 189 \ 190 switch (sizeof(__ret.val)) { \ 191 LINUXKPI_ATOMIC_8( \ 192 case 1: \ 193 while (!atomic_fcmpset_8((volatile u8 *)(ptr), \ 194 __ret.u8, __new.u8[0]) && __ret.val == (old)) \ 195 ; \ 196 break; \ 197 ) \ 198 LINUXKPI_ATOMIC_16( \ 199 case 2: \ 200 while (!atomic_fcmpset_16((volatile u16 *)(ptr), \ 201 __ret.u16, __new.u16[0]) && __ret.val == (old)) \ 202 ; \ 203 break; \ 204 ) \ 205 case 4: \ 206 while (!atomic_fcmpset_32((volatile u32 *)(ptr), \ 207 __ret.u32, __new.u32[0]) && __ret.val == (old)) \ 208 ; \ 209 break; \ 210 LINUXKPI_ATOMIC_64( \ 211 case 8: \ 212 while (!atomic_fcmpset_64((volatile u64 *)(ptr), \ 213 __ret.u64, __new.u64[0]) && __ret.val == (old)) \ 214 ; \ 215 break; \ 216 ) \ 217 } \ 218 __ret.val; \ 219 }) 220 221 #define cmpxchg_relaxed(...) cmpxchg(__VA_ARGS__) 222 223 #define xchg(ptr, new) ({ \ 224 union { \ 225 __typeof(*(ptr)) val; \ 226 u8 u8[0]; \ 227 u16 u16[0]; \ 228 u32 u32[0]; \ 229 u64 u64[0]; \ 230 } __ret, __new = { .val = (new) }; \ 231 \ 232 CTASSERT( \ 233 LINUXKPI_ATOMIC_8(sizeof(__ret.val) == 1 ||) \ 234 LINUXKPI_ATOMIC_16(sizeof(__ret.val) == 2 ||) \ 235 LINUXKPI_ATOMIC_64(sizeof(__ret.val) == 8 ||) \ 236 sizeof(__ret.val) == 4); \ 237 \ 238 switch (sizeof(__ret.val)) { \ 239 LINUXKPI_ATOMIC_8( \ 240 case 1: \ 241 __ret.val = READ_ONCE(*ptr); \ 242 while (!atomic_fcmpset_8((volatile u8 *)(ptr), \ 243 __ret.u8, __new.u8[0])) \ 244 ; \ 245 break; \ 246 ) \ 247 LINUXKPI_ATOMIC_16( \ 248 case 2: \ 249 __ret.val = READ_ONCE(*ptr); \ 250 while (!atomic_fcmpset_16((volatile u16 *)(ptr), \ 251 __ret.u16, __new.u16[0])) \ 252 ; \ 253 break; \ 254 ) \ 255 case 4: \ 256 __ret.u32[0] = atomic_swap_32((volatile u32 *)(ptr), \ 257 __new.u32[0]); \ 258 break; \ 259 LINUXKPI_ATOMIC_64( \ 260 case 8: \ 261 __ret.u64[0] = atomic_swap_64((volatile u64 *)(ptr), \ 262 __new.u64[0]); \ 263 break; \ 264 ) \ 265 } \ 266 __ret.val; \ 267 }) 268 269 #define try_cmpxchg(p, op, n) \ 270 ({ \ 271 __typeof(p) __op = (__typeof((p)))(op); \ 272 __typeof(*(p)) __o = *__op; \ 273 __typeof(*(p)) __p = __sync_val_compare_and_swap((p), (__o), (n)); \ 274 if (__p != __o) \ 275 *__op = __p; \ 276 (__p == __o); \ 277 }) 278 279 #define __atomic_try_cmpxchg(type, _p, _po, _n) \ 280 ({ \ 281 __typeof(_po) __po = (_po); \ 282 __typeof(*(_po)) __r, __o = *__po; \ 283 __r = atomic_cmpxchg##type((_p), __o, (_n)); \ 284 if (unlikely(__r != __o)) \ 285 *__po = __r; \ 286 likely(__r == __o); \ 287 }) 288 289 #define atomic_try_cmpxchg(_p, _po, _n) __atomic_try_cmpxchg(, _p, _po, _n) 290 291 static inline int 292 atomic_dec_if_positive(atomic_t *v) 293 { 294 int retval; 295 int old; 296 297 old = atomic_read(v); 298 for (;;) { 299 retval = old - 1; 300 if (unlikely(retval < 0)) 301 break; 302 if (likely(atomic_fcmpset_int(&v->counter, &old, retval))) 303 break; 304 } 305 return (retval); 306 } 307 308 #define LINUX_ATOMIC_OP(op, c_op) \ 309 static inline void atomic_##op(int i, atomic_t *v) \ 310 { \ 311 int c, old; \ 312 \ 313 c = v->counter; \ 314 while ((old = atomic_cmpxchg(v, c, c c_op i)) != c) \ 315 c = old; \ 316 } 317 318 #define LINUX_ATOMIC_FETCH_OP(op, c_op) \ 319 static inline int atomic_fetch_##op(int i, atomic_t *v) \ 320 { \ 321 int c, old; \ 322 \ 323 c = v->counter; \ 324 while ((old = atomic_cmpxchg(v, c, c c_op i)) != c) \ 325 c = old; \ 326 \ 327 return (c); \ 328 } 329 330 static inline int 331 atomic_fetch_inc(atomic_t *v) 332 { 333 334 return ((atomic_inc_return(v) - 1)); 335 } 336 337 LINUX_ATOMIC_OP(or, |) 338 LINUX_ATOMIC_OP(and, &) 339 LINUX_ATOMIC_OP(andnot, &~) 340 LINUX_ATOMIC_OP(xor, ^) 341 342 LINUX_ATOMIC_FETCH_OP(or, |) 343 LINUX_ATOMIC_FETCH_OP(and, &) 344 LINUX_ATOMIC_FETCH_OP(andnot, &~) 345 LINUX_ATOMIC_FETCH_OP(xor, ^) 346 347 #endif /* _LINUXKPI_ASM_ATOMIC_H_ */ 348