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 #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(__mips__) && !(defined(__mips_n32) || \ 170 defined(__mips_n64))) || (defined(__powerpc__) && \ 171 !defined(__powerpc64__))) 172 #define LINUXKPI_ATOMIC_64(...) __VA_ARGS__ 173 #else 174 #define LINUXKPI_ATOMIC_64(...) 175 #endif 176 177 #define cmpxchg(ptr, old, new) ({ \ 178 union { \ 179 __typeof(*(ptr)) val; \ 180 u8 u8[0]; \ 181 u16 u16[0]; \ 182 u32 u32[0]; \ 183 u64 u64[0]; \ 184 } __ret = { .val = (old) }, __new = { .val = (new) }; \ 185 \ 186 CTASSERT( \ 187 LINUXKPI_ATOMIC_8(sizeof(__ret.val) == 1 ||) \ 188 LINUXKPI_ATOMIC_16(sizeof(__ret.val) == 2 ||) \ 189 LINUXKPI_ATOMIC_64(sizeof(__ret.val) == 8 ||) \ 190 sizeof(__ret.val) == 4); \ 191 \ 192 switch (sizeof(__ret.val)) { \ 193 LINUXKPI_ATOMIC_8( \ 194 case 1: \ 195 while (!atomic_fcmpset_8((volatile u8 *)(ptr), \ 196 __ret.u8, __new.u8[0]) && __ret.val == (old)) \ 197 ; \ 198 break; \ 199 ) \ 200 LINUXKPI_ATOMIC_16( \ 201 case 2: \ 202 while (!atomic_fcmpset_16((volatile u16 *)(ptr), \ 203 __ret.u16, __new.u16[0]) && __ret.val == (old)) \ 204 ; \ 205 break; \ 206 ) \ 207 case 4: \ 208 while (!atomic_fcmpset_32((volatile u32 *)(ptr), \ 209 __ret.u32, __new.u32[0]) && __ret.val == (old)) \ 210 ; \ 211 break; \ 212 LINUXKPI_ATOMIC_64( \ 213 case 8: \ 214 while (!atomic_fcmpset_64((volatile u64 *)(ptr), \ 215 __ret.u64, __new.u64[0]) && __ret.val == (old)) \ 216 ; \ 217 break; \ 218 ) \ 219 } \ 220 __ret.val; \ 221 }) 222 223 #define cmpxchg_relaxed(...) cmpxchg(__VA_ARGS__) 224 225 #define xchg(ptr, new) ({ \ 226 union { \ 227 __typeof(*(ptr)) val; \ 228 u8 u8[0]; \ 229 u16 u16[0]; \ 230 u32 u32[0]; \ 231 u64 u64[0]; \ 232 } __ret, __new = { .val = (new) }; \ 233 \ 234 CTASSERT( \ 235 LINUXKPI_ATOMIC_8(sizeof(__ret.val) == 1 ||) \ 236 LINUXKPI_ATOMIC_16(sizeof(__ret.val) == 2 ||) \ 237 LINUXKPI_ATOMIC_64(sizeof(__ret.val) == 8 ||) \ 238 sizeof(__ret.val) == 4); \ 239 \ 240 switch (sizeof(__ret.val)) { \ 241 LINUXKPI_ATOMIC_8( \ 242 case 1: \ 243 __ret.val = READ_ONCE(*ptr); \ 244 while (!atomic_fcmpset_8((volatile u8 *)(ptr), \ 245 __ret.u8, __new.u8[0])) \ 246 ; \ 247 break; \ 248 ) \ 249 LINUXKPI_ATOMIC_16( \ 250 case 2: \ 251 __ret.val = READ_ONCE(*ptr); \ 252 while (!atomic_fcmpset_16((volatile u16 *)(ptr), \ 253 __ret.u16, __new.u16[0])) \ 254 ; \ 255 break; \ 256 ) \ 257 case 4: \ 258 __ret.u32[0] = atomic_swap_32((volatile u32 *)(ptr), \ 259 __new.u32[0]); \ 260 break; \ 261 LINUXKPI_ATOMIC_64( \ 262 case 8: \ 263 __ret.u64[0] = atomic_swap_64((volatile u64 *)(ptr), \ 264 __new.u64[0]); \ 265 break; \ 266 ) \ 267 } \ 268 __ret.val; \ 269 }) 270 271 static inline int 272 atomic_dec_if_positive(atomic_t *v) 273 { 274 int retval; 275 int old; 276 277 old = atomic_read(v); 278 for (;;) { 279 retval = old - 1; 280 if (unlikely(retval < 0)) 281 break; 282 if (likely(atomic_fcmpset_int(&v->counter, &old, retval))) 283 break; 284 } 285 return (retval); 286 } 287 288 #define LINUX_ATOMIC_OP(op, c_op) \ 289 static inline void atomic_##op(int i, atomic_t *v) \ 290 { \ 291 int c, old; \ 292 \ 293 c = v->counter; \ 294 while ((old = atomic_cmpxchg(v, c, c c_op i)) != c) \ 295 c = old; \ 296 } 297 298 #define LINUX_ATOMIC_FETCH_OP(op, c_op) \ 299 static inline int atomic_fetch_##op(int i, atomic_t *v) \ 300 { \ 301 int c, old; \ 302 \ 303 c = v->counter; \ 304 while ((old = atomic_cmpxchg(v, c, c c_op i)) != c) \ 305 c = old; \ 306 \ 307 return (c); \ 308 } 309 310 LINUX_ATOMIC_OP(or, |) 311 LINUX_ATOMIC_OP(and, &) 312 LINUX_ATOMIC_OP(andnot, &~) 313 LINUX_ATOMIC_OP(xor, ^) 314 315 LINUX_ATOMIC_FETCH_OP(or, |) 316 LINUX_ATOMIC_FETCH_OP(and, &) 317 LINUX_ATOMIC_FETCH_OP(andnot, &~) 318 LINUX_ATOMIC_FETCH_OP(xor, ^) 319 320 #endif /* _ASM_ATOMIC_H_ */ 321