1 /*- 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2013-2016 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 #ifndef _ASM_ATOMIC_H_ 32 #define _ASM_ATOMIC_H_ 33 34 #include <sys/cdefs.h> 35 #include <sys/types.h> 36 #include <machine/atomic.h> 37 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_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0) 53 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) 54 #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0) 55 #define atomic_dec_return(v) atomic_sub_return(1, (v)) 56 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) 57 58 static inline int 59 atomic_add_return(int i, atomic_t *v) 60 { 61 return i + atomic_fetchadd_int(&v->counter, i); 62 } 63 64 static inline int 65 atomic_sub_return(int i, atomic_t *v) 66 { 67 return atomic_fetchadd_int(&v->counter, -i) - i; 68 } 69 70 static inline void 71 atomic_set(atomic_t *v, int i) 72 { 73 atomic_store_rel_int(&v->counter, i); 74 } 75 76 static inline int 77 atomic_read(atomic_t *v) 78 { 79 return atomic_load_acq_int(&v->counter); 80 } 81 82 static inline int 83 atomic_inc(atomic_t *v) 84 { 85 return atomic_fetchadd_int(&v->counter, 1) + 1; 86 } 87 88 static inline int 89 atomic_dec(atomic_t *v) 90 { 91 return atomic_fetchadd_int(&v->counter, -1) - 1; 92 } 93 94 static inline int 95 atomic_add_unless(atomic_t *v, int a, int u) 96 { 97 int c; 98 99 for (;;) { 100 c = atomic_read(v); 101 if (unlikely(c == u)) 102 break; 103 if (likely(atomic_cmpset_int(&v->counter, c, c + a))) 104 break; 105 } 106 return (c != u); 107 } 108 109 #endif /* _ASM_ATOMIC_H_ */ 110