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 = 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 } 121 122 static inline void 123 atomic_clear_mask(unsigned int mask, atomic_t *v) 124 { 125 atomic_clear_int(&v->counter, mask); 126 } 127 128 static inline int 129 atomic_xchg(atomic_t *v, int i) 130 { 131 return (atomic_swap_int(&v->counter, i)); 132 } 133 134 static inline int 135 atomic_cmpxchg(atomic_t *v, int old, int new) 136 { 137 int ret = old; 138 139 for (;;) { 140 if (atomic_fcmpset_int(&v->counter, &ret, new)) 141 break; 142 if (ret != old) 143 break; 144 } 145 return (ret); 146 } 147 148 #if defined(__amd64__) || defined(__arm64__) || defined(__i386__) 149 #define LINUXKPI_ATOMIC_8(...) __VA_ARGS__ 150 #define LINUXKPI_ATOMIC_16(...) __VA_ARGS__ 151 #else 152 #define LINUXKPI_ATOMIC_8(...) 153 #define LINUXKPI_ATOMIC_16(...) 154 #endif 155 156 #if !(defined(i386) || (defined(__mips__) && !(defined(__mips_n32) || \ 157 defined(__mips_n64))) || (defined(__powerpc__) && \ 158 !defined(__powerpc64__))) 159 #define LINUXKPI_ATOMIC_64(...) __VA_ARGS__ 160 #else 161 #define LINUXKPI_ATOMIC_64(...) 162 #endif 163 164 #define cmpxchg(ptr, old, new) ({ \ 165 union { \ 166 __typeof(*(ptr)) val; \ 167 u8 u8[0]; \ 168 u16 u16[0]; \ 169 u32 u32[0]; \ 170 u64 u64[0]; \ 171 } __ret = { .val = (old) }, __new = { .val = (new) }; \ 172 \ 173 CTASSERT( \ 174 LINUXKPI_ATOMIC_8(sizeof(__ret.val) == 1 ||) \ 175 LINUXKPI_ATOMIC_16(sizeof(__ret.val) == 2 ||) \ 176 LINUXKPI_ATOMIC_64(sizeof(__ret.val) == 8 ||) \ 177 sizeof(__ret.val) == 4); \ 178 \ 179 switch (sizeof(__ret.val)) { \ 180 LINUXKPI_ATOMIC_8( \ 181 case 1: \ 182 while (!atomic_fcmpset_8((volatile u8 *)(ptr), \ 183 __ret.u8, __new.u8[0]) && __ret.val == (old)) \ 184 ; \ 185 break; \ 186 ) \ 187 LINUXKPI_ATOMIC_16( \ 188 case 2: \ 189 while (!atomic_fcmpset_16((volatile u16 *)(ptr), \ 190 __ret.u16, __new.u16[0]) && __ret.val == (old)) \ 191 ; \ 192 break; \ 193 ) \ 194 case 4: \ 195 while (!atomic_fcmpset_32((volatile u32 *)(ptr), \ 196 __ret.u32, __new.u32[0]) && __ret.val == (old)) \ 197 ; \ 198 break; \ 199 LINUXKPI_ATOMIC_64( \ 200 case 8: \ 201 while (!atomic_fcmpset_64((volatile u64 *)(ptr), \ 202 __ret.u64, __new.u64[0]) && __ret.val == (old)) \ 203 ; \ 204 break; \ 205 ) \ 206 } \ 207 __ret.val; \ 208 }) 209 210 #define cmpxchg_relaxed(...) cmpxchg(__VA_ARGS__) 211 212 #define xchg(ptr, new) ({ \ 213 union { \ 214 __typeof(*(ptr)) val; \ 215 u8 u8[0]; \ 216 u16 u16[0]; \ 217 u32 u32[0]; \ 218 u64 u64[0]; \ 219 } __ret, __new = { .val = (new) }; \ 220 \ 221 CTASSERT( \ 222 LINUXKPI_ATOMIC_8(sizeof(__ret.val) == 1 ||) \ 223 LINUXKPI_ATOMIC_16(sizeof(__ret.val) == 2 ||) \ 224 LINUXKPI_ATOMIC_64(sizeof(__ret.val) == 8 ||) \ 225 sizeof(__ret.val) == 4); \ 226 \ 227 switch (sizeof(__ret.val)) { \ 228 LINUXKPI_ATOMIC_8( \ 229 case 1: \ 230 __ret.val = READ_ONCE(*ptr); \ 231 while (!atomic_fcmpset_8((volatile u8 *)(ptr), \ 232 __ret.u8, __new.u8[0])) \ 233 ; \ 234 break; \ 235 ) \ 236 LINUXKPI_ATOMIC_16( \ 237 case 2: \ 238 __ret.val = READ_ONCE(*ptr); \ 239 while (!atomic_fcmpset_16((volatile u16 *)(ptr), \ 240 __ret.u16, __new.u16[0])) \ 241 ; \ 242 break; \ 243 ) \ 244 case 4: \ 245 __ret.u32[0] = atomic_swap_32((volatile u32 *)(ptr), \ 246 __new.u32[0]); \ 247 break; \ 248 LINUXKPI_ATOMIC_64( \ 249 case 8: \ 250 __ret.u64[0] = atomic_swap_64((volatile u64 *)(ptr), \ 251 __new.u64[0]); \ 252 break; \ 253 ) \ 254 } \ 255 __ret.val; \ 256 }) 257 258 static inline int 259 atomic_dec_if_positive(atomic_t *v) 260 { 261 int retval; 262 int old; 263 264 old = atomic_read(v); 265 for (;;) { 266 retval = old - 1; 267 if (unlikely(retval < 0)) 268 break; 269 if (likely(atomic_fcmpset_int(&v->counter, &old, retval))) 270 break; 271 } 272 return (retval); 273 } 274 275 #define LINUX_ATOMIC_OP(op, c_op) \ 276 static inline void atomic_##op(int i, atomic_t *v) \ 277 { \ 278 int c, old; \ 279 \ 280 c = v->counter; \ 281 while ((old = atomic_cmpxchg(v, c, c c_op i)) != c) \ 282 c = old; \ 283 } 284 285 #define LINUX_ATOMIC_FETCH_OP(op, c_op) \ 286 static inline int atomic_fetch_##op(int i, atomic_t *v) \ 287 { \ 288 int c, old; \ 289 \ 290 c = v->counter; \ 291 while ((old = atomic_cmpxchg(v, c, c c_op i)) != c) \ 292 c = old; \ 293 \ 294 return (c); \ 295 } 296 297 LINUX_ATOMIC_OP(or, |) 298 LINUX_ATOMIC_OP(and, &) 299 LINUX_ATOMIC_OP(andnot, &~) 300 LINUX_ATOMIC_OP(xor, ^) 301 302 LINUX_ATOMIC_FETCH_OP(or, |) 303 LINUX_ATOMIC_FETCH_OP(and, &) 304 LINUX_ATOMIC_FETCH_OP(andnot, &~) 305 LINUX_ATOMIC_FETCH_OP(xor, ^) 306 307 #endif /* _ASM_ATOMIC_H_ */ 308