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 41 typedef 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 60 static inline int 61 atomic_add_return(int i, atomic_t *v) 62 { 63 return i + atomic_fetchadd_int(&v->counter, i); 64 } 65 66 static inline int 67 atomic_sub_return(int i, atomic_t *v) 68 { 69 return atomic_fetchadd_int(&v->counter, -i) - i; 70 } 71 72 static inline void 73 atomic_set(atomic_t *v, int i) 74 { 75 WRITE_ONCE(v->counter, i); 76 } 77 78 static inline void 79 atomic_set_release(atomic_t *v, int i) 80 { 81 atomic_store_rel_int(&v->counter, i); 82 } 83 84 static inline void 85 atomic_set_mask(unsigned int mask, atomic_t *v) 86 { 87 atomic_set_int(&v->counter, mask); 88 } 89 90 static inline int 91 atomic_read(const atomic_t *v) 92 { 93 return READ_ONCE(v->counter); 94 } 95 96 static inline int 97 atomic_inc(atomic_t *v) 98 { 99 return atomic_fetchadd_int(&v->counter, 1) + 1; 100 } 101 102 static inline int 103 atomic_dec(atomic_t *v) 104 { 105 return atomic_fetchadd_int(&v->counter, -1) - 1; 106 } 107 108 static inline int 109 atomic_add_unless(atomic_t *v, int a, int u) 110 { 111 int c; 112 113 for (;;) { 114 c = atomic_read(v); 115 if (unlikely(c == u)) 116 break; 117 if (likely(atomic_cmpset_int(&v->counter, c, c + a))) 118 break; 119 } 120 return (c != u); 121 } 122 123 static inline void 124 atomic_clear_mask(unsigned int mask, atomic_t *v) 125 { 126 atomic_clear_int(&v->counter, mask); 127 } 128 129 static inline int 130 atomic_xchg(atomic_t *v, int i) 131 { 132 #if !defined(__mips__) 133 return (atomic_swap_int(&v->counter, i)); 134 #else 135 int ret; 136 for (;;) { 137 ret = READ_ONCE(v->counter); 138 if (atomic_cmpset_int(&v->counter, ret, i)) 139 break; 140 } 141 return (ret); 142 #endif 143 } 144 145 static inline int 146 atomic_cmpxchg(atomic_t *v, int old, int new) 147 { 148 int ret = old; 149 150 for (;;) { 151 if (atomic_cmpset_int(&v->counter, old, new)) 152 break; 153 ret = READ_ONCE(v->counter); 154 if (ret != old) 155 break; 156 } 157 return (ret); 158 } 159 160 #if defined(__amd64__) || defined(__arm64__) || defined(__i386__) 161 #define LINUXKPI_ATOMIC_8(...) __VA_ARGS__ 162 #define LINUXKPI_ATOMIC_16(...) __VA_ARGS__ 163 #else 164 #define LINUXKPI_ATOMIC_8(...) 165 #define LINUXKPI_ATOMIC_16(...) 166 #endif 167 168 #if !(defined(i386) || (defined(__mips__) && !(defined(__mips_n32) || \ 169 defined(__mips_n64))) || (defined(__powerpc__) && \ 170 !defined(__powerpc64__))) 171 #define LINUXKPI_ATOMIC_64(...) __VA_ARGS__ 172 #else 173 #define LINUXKPI_ATOMIC_64(...) 174 #endif 175 176 #define cmpxchg(ptr, old, new) ({ \ 177 union { \ 178 __typeof(*(ptr)) val; \ 179 u8 u8[0]; \ 180 u16 u16[0]; \ 181 u32 u32[0]; \ 182 u64 u64[0]; \ 183 } __ret = { .val = (old) }, __new = { .val = (new) }; \ 184 \ 185 CTASSERT( \ 186 LINUXKPI_ATOMIC_8(sizeof(__ret.val) == 1 ||) \ 187 LINUXKPI_ATOMIC_16(sizeof(__ret.val) == 2 ||) \ 188 LINUXKPI_ATOMIC_64(sizeof(__ret.val) == 8 ||) \ 189 sizeof(__ret.val) == 4); \ 190 \ 191 switch (sizeof(__ret.val)) { \ 192 LINUXKPI_ATOMIC_8( \ 193 case 1: \ 194 while (!atomic_fcmpset_8((volatile u8 *)(ptr), \ 195 __ret.u8, __new.u8[0]) && __ret.val == (old)) \ 196 ; \ 197 break; \ 198 ) \ 199 LINUXKPI_ATOMIC_16( \ 200 case 2: \ 201 while (!atomic_fcmpset_16((volatile u16 *)(ptr), \ 202 __ret.u16, __new.u16[0]) && __ret.val == (old)) \ 203 ; \ 204 break; \ 205 ) \ 206 case 4: \ 207 while (!atomic_fcmpset_32((volatile u32 *)(ptr), \ 208 __ret.u32, __new.u32[0]) && __ret.val == (old)) \ 209 ; \ 210 break; \ 211 LINUXKPI_ATOMIC_64( \ 212 case 8: \ 213 while (!atomic_fcmpset_64((volatile u64 *)(ptr), \ 214 __ret.u64, __new.u64[0]) && __ret.val == (old)) \ 215 ; \ 216 break; \ 217 ) \ 218 } \ 219 __ret.val; \ 220 }) 221 222 #define cmpxchg_relaxed(...) cmpxchg(__VA_ARGS__) 223 224 #define xchg(ptr, new) ({ \ 225 union { \ 226 __typeof(*(ptr)) val; \ 227 u8 u8[0]; \ 228 u16 u16[0]; \ 229 u32 u32[0]; \ 230 u64 u64[0]; \ 231 } __ret, __new = { .val = (new) }; \ 232 \ 233 CTASSERT( \ 234 LINUXKPI_ATOMIC_8(sizeof(__ret.val) == 1 ||) \ 235 LINUXKPI_ATOMIC_16(sizeof(__ret.val) == 2 ||) \ 236 LINUXKPI_ATOMIC_64(sizeof(__ret.val) == 8 ||) \ 237 sizeof(__ret.val) == 4); \ 238 \ 239 switch (sizeof(__ret.val)) { \ 240 LINUXKPI_ATOMIC_8( \ 241 case 1: \ 242 __ret.val = READ_ONCE(*ptr); \ 243 while (!atomic_fcmpset_8((volatile u8 *)(ptr), \ 244 __ret.u8, __new.u8[0])) \ 245 ; \ 246 break; \ 247 ) \ 248 LINUXKPI_ATOMIC_16( \ 249 case 2: \ 250 __ret.val = READ_ONCE(*ptr); \ 251 while (!atomic_fcmpset_16((volatile u16 *)(ptr), \ 252 __ret.u16, __new.u16[0])) \ 253 ; \ 254 break; \ 255 ) \ 256 case 4: \ 257 __ret.u32[0] = atomic_swap_32((volatile u32 *)(ptr), \ 258 __new.u32[0]); \ 259 break; \ 260 LINUXKPI_ATOMIC_64( \ 261 case 8: \ 262 __ret.u64[0] = atomic_swap_64((volatile u64 *)(ptr), \ 263 __new.u64[0]); \ 264 break; \ 265 ) \ 266 } \ 267 __ret.val; \ 268 }) 269 270 static inline int 271 atomic_dec_if_positive(atomic_t *v) 272 { 273 int retval; 274 int old; 275 276 old = atomic_read(v); 277 for (;;) { 278 retval = old - 1; 279 if (unlikely(retval < 0)) 280 break; 281 if (likely(atomic_fcmpset_int(&v->counter, &old, retval))) 282 break; 283 } 284 return (retval); 285 } 286 287 #define LINUX_ATOMIC_OP(op, c_op) \ 288 static inline void atomic_##op(int i, atomic_t *v) \ 289 { \ 290 int c, old; \ 291 \ 292 c = v->counter; \ 293 while ((old = atomic_cmpxchg(v, c, c c_op i)) != c) \ 294 c = old; \ 295 } 296 297 #define LINUX_ATOMIC_FETCH_OP(op, c_op) \ 298 static inline int atomic_fetch_##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 return (c); \ 307 } 308 309 LINUX_ATOMIC_OP(or, |) 310 LINUX_ATOMIC_OP(and, &) 311 LINUX_ATOMIC_OP(andnot, &~) 312 LINUX_ATOMIC_OP(xor, ^) 313 314 LINUX_ATOMIC_FETCH_OP(or, |) 315 LINUX_ATOMIC_FETCH_OP(and, &) 316 LINUX_ATOMIC_FETCH_OP(andnot, &~) 317 LINUX_ATOMIC_FETCH_OP(xor, ^) 318 319 #endif /* _ASM_ATOMIC_H_ */ 320