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 typedef struct { 39 volatile int counter; 40 } atomic_t; 41 42 /*------------------------------------------------------------------------* 43 * 32-bit atomic operations 44 *------------------------------------------------------------------------*/ 45 46 #define atomic_add(i, v) atomic_add_return((i), (v)) 47 #define atomic_sub(i, v) atomic_sub_return((i), (v)) 48 #define atomic_inc_return(v) atomic_add_return(1, (v)) 49 #define atomic_add_negative(i, v) (atomic_add_return((i), (v)) < 0) 50 #define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0) 51 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) 52 #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0) 53 #define atomic_dec_return(v) atomic_sub_return(1, (v)) 54 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) 55 56 static inline int 57 atomic_add_return(int i, atomic_t *v) 58 { 59 return i + atomic_fetchadd_int(&v->counter, i); 60 } 61 62 static inline int 63 atomic_sub_return(int i, atomic_t *v) 64 { 65 return atomic_fetchadd_int(&v->counter, -i) - i; 66 } 67 68 static inline void 69 atomic_set(atomic_t *v, int i) 70 { 71 atomic_store_rel_int(&v->counter, i); 72 } 73 74 static inline int 75 atomic_read(atomic_t *v) 76 { 77 return atomic_load_acq_int(&v->counter); 78 } 79 80 static inline int 81 atomic_inc(atomic_t *v) 82 { 83 return atomic_fetchadd_int(&v->counter, 1) + 1; 84 } 85 86 static inline int 87 atomic_dec(atomic_t *v) 88 { 89 return atomic_fetchadd_int(&v->counter, -1) - 1; 90 } 91 92 static inline int 93 atomic_add_unless(atomic_t *v, int a, int u) 94 { 95 int c; 96 97 for (;;) { 98 c = atomic_read(v); 99 if (unlikely(c == u)) 100 break; 101 if (likely(atomic_cmpset_int(&v->counter, c, c + a))) 102 break; 103 } 104 return (c != u); 105 } 106 107 #endif /* _ASM_ATOMIC_H_ */ 108