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 #ifndef _ATOMIC_LONG_H_ 32 #define _ATOMIC_LONG_H_ 33 34 #include <linux/compiler.h> 35 #include <sys/types.h> 36 #include <machine/atomic.h> 37 38 #define ATOMIC_LONG_INIT(x) { .counter = (x) } 39 40 typedef struct { 41 volatile long counter; 42 } atomic_long_t; 43 44 #define atomic_long_add(i, v) atomic_long_add_return((i), (v)) 45 #define atomic_long_inc_return(v) atomic_long_add_return(1, (v)) 46 #define atomic_long_inc_not_zero(v) atomic_long_add_unless((v), 1, 0) 47 48 static inline long 49 atomic_long_add_return(long i, atomic_long_t *v) 50 { 51 return i + atomic_fetchadd_long(&v->counter, i); 52 } 53 54 static inline void 55 atomic_long_set(atomic_long_t *v, long i) 56 { 57 WRITE_ONCE(v->counter, i); 58 } 59 60 static inline long 61 atomic_long_read(atomic_long_t *v) 62 { 63 return READ_ONCE(v->counter); 64 } 65 66 static inline long 67 atomic_long_inc(atomic_long_t *v) 68 { 69 return atomic_fetchadd_long(&v->counter, 1) + 1; 70 } 71 72 static inline long 73 atomic_long_dec(atomic_long_t *v) 74 { 75 return atomic_fetchadd_long(&v->counter, -1) - 1; 76 } 77 78 static inline long 79 atomic_long_xchg(atomic_long_t *v, long val) 80 { 81 return atomic_swap_long(&v->counter, val); 82 } 83 84 static inline long 85 atomic_long_cmpxchg(atomic_long_t *v, long old, long new) 86 { 87 long ret = old; 88 89 for (;;) { 90 if (atomic_fcmpset_long(&v->counter, &ret, new)) 91 break; 92 if (ret != old) 93 break; 94 } 95 return (ret); 96 } 97 98 static inline int 99 atomic_long_add_unless(atomic_long_t *v, long a, long u) 100 { 101 long c = atomic_long_read(v); 102 103 for (;;) { 104 if (unlikely(c == u)) 105 break; 106 if (likely(atomic_fcmpset_long(&v->counter, &c, c + a))) 107 break; 108 } 109 return (c != u); 110 } 111 112 static inline long 113 atomic_long_dec_and_test(atomic_long_t *v) 114 { 115 long i = atomic_long_add(-1, v); 116 return i == 0 ; 117 } 118 119 #endif /* _ATOMIC_LONG_H_ */ 120