1 /*- 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2013-2017 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(__i386__) || defined(__amd64__) || \ 133 defined(__arm__) || defined(__aarch64__) || \ 134 defined(__powerpc__) 135 return (atomic_swap_int(&v->counter, i)); 136 #else 137 int ret; 138 for (;;) { 139 ret = READ_ONCE(v->counter); 140 if (atomic_cmpset_int(&v->counter, ret, i)) 141 break; 142 } 143 return (ret); 144 #endif 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_cmpset_int(&v->counter, old, new)) 154 break; 155 ret = READ_ONCE(v->counter); 156 if (ret != old) 157 break; 158 } 159 return (ret); 160 } 161 162 #define cmpxchg(ptr, old, new) ({ \ 163 __typeof(*(ptr)) __ret; \ 164 \ 165 CTASSERT(sizeof(__ret) == 1 || sizeof(__ret) == 2 || \ 166 sizeof(__ret) == 4 || sizeof(__ret) == 8); \ 167 \ 168 __ret = (old); \ 169 switch (sizeof(__ret)) { \ 170 case 1: \ 171 while (!atomic_fcmpset_8((volatile int8_t *)(ptr), \ 172 (int8_t *)&__ret, (new)) && __ret == (old)) \ 173 ; \ 174 break; \ 175 case 2: \ 176 while (!atomic_fcmpset_16((volatile int16_t *)(ptr), \ 177 (int16_t *)&__ret, (new)) && __ret == (old)) \ 178 ; \ 179 break; \ 180 case 4: \ 181 while (!atomic_fcmpset_32((volatile int32_t *)(ptr), \ 182 (int32_t *)&__ret, (new)) && __ret == (old)) \ 183 ; \ 184 break; \ 185 case 8: \ 186 while (!atomic_fcmpset_64((volatile int64_t *)(ptr), \ 187 (int64_t *)&__ret, (new)) && __ret == (old)) \ 188 ; \ 189 break; \ 190 } \ 191 __ret; \ 192 }) 193 194 #define cmpxchg_relaxed(...) cmpxchg(__VA_ARGS__) 195 196 #define xchg(ptr, v) ({ \ 197 __typeof(*(ptr)) __ret; \ 198 \ 199 __ret = *(ptr); \ 200 *(ptr) = v; \ 201 __ret; \ 202 }) 203 204 #define LINUX_ATOMIC_OP(op, c_op) \ 205 static inline void atomic_##op(int i, atomic_t *v) \ 206 { \ 207 int c, old; \ 208 \ 209 c = v->counter; \ 210 while ((old = atomic_cmpxchg(v, c, c c_op i)) != c) \ 211 c = old; \ 212 } 213 214 #define LINUX_ATOMIC_FETCH_OP(op, c_op) \ 215 static inline int atomic_fetch_##op(int i, atomic_t *v) \ 216 { \ 217 int c, old; \ 218 \ 219 c = v->counter; \ 220 while ((old = atomic_cmpxchg(v, c, c c_op i)) != c) \ 221 c = old; \ 222 \ 223 return (c); \ 224 } 225 226 LINUX_ATOMIC_OP(or, |) 227 LINUX_ATOMIC_OP(and, &) 228 LINUX_ATOMIC_OP(andnot, &~) 229 LINUX_ATOMIC_OP(xor, ^) 230 231 LINUX_ATOMIC_FETCH_OP(or, |) 232 LINUX_ATOMIC_FETCH_OP(and, &) 233 LINUX_ATOMIC_FETCH_OP(andnot, &~) 234 LINUX_ATOMIC_FETCH_OP(xor, ^) 235 236 #endif /* _ASM_ATOMIC_H_ */ 237